[PATCH net-next v2 6/9] net: phy: add backplane kr driver support

From: Florinel Iordache
Date: Fri Apr 24 2020 - 08:47:52 EST

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Add support for backplane kr generic driver including link training
(ieee802.3ap/ba) and fixed equalization algorithm

Signed-off-by: Florinel Iordache <florinel.iordache@xxxxxxx>
---
drivers/net/phy/Kconfig | 2 +
drivers/net/phy/Makefile | 1 +
drivers/net/phy/backplane/Kconfig | 20 +
drivers/net/phy/backplane/Makefile | 9 +
drivers/net/phy/backplane/backplane.c | 1626 +++++++++++++++++++++++++++++
drivers/net/phy/backplane/backplane.h | 293 ++++++
drivers/net/phy/backplane/eq_fixed.c | 83 ++
drivers/net/phy/backplane/equalization.h | 283 +++++
drivers/net/phy/backplane/link_training.c | 1529 +++++++++++++++++++++++++++
drivers/net/phy/backplane/link_training.h | 32 +
10 files changed, 3878 insertions(+)
create mode 100644 drivers/net/phy/backplane/Kconfig
create mode 100644 drivers/net/phy/backplane/Makefile
create mode 100644 drivers/net/phy/backplane/backplane.c
create mode 100644 drivers/net/phy/backplane/backplane.h
create mode 100644 drivers/net/phy/backplane/eq_fixed.c
create mode 100644 drivers/net/phy/backplane/equalization.h
create mode 100644 drivers/net/phy/backplane/link_training.c
create mode 100644 drivers/net/phy/backplane/link_training.h

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 3fa33d2..75baf46 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -530,6 +530,8 @@ config XILINX_GMII2RGMII
the Reduced Gigabit Media Independent Interface(RGMII) between
Ethernet physical media devices and the Gigabit Ethernet controller.

+source "drivers/net/phy/backplane/Kconfig"
+
endif # PHYLIB

config MICREL_KS8995MA
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 2f5c709..a642e44 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -102,3 +102,4 @@ obj-$(CONFIG_STE10XP) += ste10Xp.o
obj-$(CONFIG_TERANETICS_PHY) += teranetics.o
obj-$(CONFIG_VITESSE_PHY) += vitesse.o
obj-$(CONFIG_XILINX_GMII2RGMII) += xilinx_gmii2rgmii.o
+obj-$(CONFIG_ETH_BACKPLANE) += backplane/
diff --git a/drivers/net/phy/backplane/Kconfig b/drivers/net/phy/backplane/Kconfig
new file mode 100644
index 0000000..9ec54b5
--- /dev/null
+++ b/drivers/net/phy/backplane/Kconfig
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+config ETH_BACKPLANE
+ tristate "Ethernet Backplane support"
+ depends on OF_MDIO
+ help
+ This module provides driver support for Ethernet Operation over
+ Electrical Backplanes. It includes Backplane generic
+ driver including support for Link Training (IEEE802.3ap/ba).
+ Based on the link quality, a signal equalization is required.
+ The standard specifies that a start-up algorithm should be in place
+ in order to get the link up.
+
+config ETH_BACKPLANE_FIXED
+ tristate "Fixed: No Equalization algorithm"
+ depends on ETH_BACKPLANE
+ help
+ This module provides a driver to setup fixed user configurable
+ coefficient values for backplanes equalization. This means
+ No Equalization algorithm is used to adapt the initial coefficients
+ initially set by the user.
\ No newline at end of file
diff --git a/drivers/net/phy/backplane/Makefile b/drivers/net/phy/backplane/Makefile
new file mode 100644
index 0000000..ded6f2d
--- /dev/null
+++ b/drivers/net/phy/backplane/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+#
+# Makefile for Ethernet Backplane driver
+#
+
+obj-$(CONFIG_ETH_BACKPLANE) += eth_backplane.o
+obj-$(CONFIG_ETH_BACKPLANE_FIXED) += eq_fixed.o
+
+eth_backplane-objs := backplane.o link_training.o
diff --git a/drivers/net/phy/backplane/backplane.c b/drivers/net/phy/backplane/backplane.c
new file mode 100644
index 0000000..fefc1f4
--- /dev/null
+++ b/drivers/net/phy/backplane/backplane.c
@@ -0,0 +1,1626 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/* Backplane driver
+ *
+ * Copyright 2015 Freescale Semiconductor, Inc.
+ * Copyright 2018-2020 NXP
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mii.h>
+#include <linux/mdio.h>
+#include <linux/ethtool.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_net.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/timer.h>
+#include <linux/delay.h>
+#include <linux/workqueue.h>
+#include <linux/netdevice.h>
+#include <linux/list.h>
+
+#include "backplane.h"
+#include "link_training.h"
+
+/* KR timeouts in milliseconds */
+#define KR_TIMEOUT_1 100
+#define KR_TIMEOUT_2 1000
+#define KR_AN_TIMEOUT 3000
+#define KR_LT_TIMEOUT 500
+
+/* KR timings in interations */
+#define KR_AN_WAIT_ITERATIONS 5
+#define KR_TRAIN_STEP_ITERATIONS 2
+#define CDR_LOCK_RETRY_COUNT 3
+
+/* AN register initialization */
+#define AN_CTRL_INIT 0x1200
+
+/* AN status register (Clause 45) (MMD 7): MDIO_STAT1 */
+#define AN_LINK_UP_MASK 0x04
+
+/* Backplane Ethernet status (Register 7.48) */
+#define AN_BP_ETH_STATUS 48
+
+/* AN masks: Backplane Ethernet status: register 7.48 */
+#define AN_MASK_10GBASE_KR 0x08
+#define AN_MASK_40GBASE_KR4 0x20
+
+/* AN advertisement 1 (Register 7.17) */
+#define AN_ADVERTISEMENT_1 17
+
+/* AN advertisement initialization for register 7.17 */
+#define AN_ADV1_KR_INIT_10G 0x85
+#define AN_ADV1_KR_INIT_40G 0x105
+
+/* Backplane custom logging */
+#define bpdev_fn(fn) \
+void bpdev_##fn(struct phy_device *phydev, char *fmt, ...) \
+{ \
+ struct va_format vaf = { \
+ .fmt = fmt, \
+ }; \
+ va_list args; \
+ va_start(args, fmt); \
+ vaf.va = &args; \
+ if (!phydev->attached_dev) \
+ dev_##fn(&phydev->mdio.dev, "%pV", &vaf); \
+ else \
+ dev_##fn(&phydev->mdio.dev, "%s: %pV", \
+ netdev_name(phydev->attached_dev), &vaf); \
+ va_end(args); \
+}
+
+bpdev_fn(err)
+EXPORT_SYMBOL(bpdev_err);
+
+bpdev_fn(warn)
+EXPORT_SYMBOL(bpdev_warn);
+
+bpdev_fn(info)
+EXPORT_SYMBOL(bpdev_info);
+
+bpdev_fn(dbg)
+EXPORT_SYMBOL(bpdev_dbg);
+
+/* Backplane features */
+__ETHTOOL_DECLARE_LINK_MODE_MASK(backplane_features) __ro_after_init;
+EXPORT_SYMBOL(backplane_features);
+
+const int backplane_common_features_array[] = {
+ ETHTOOL_LINK_MODE_Backplane_BIT,
+ ETHTOOL_LINK_MODE_Autoneg_BIT,
+ ETHTOOL_LINK_MODE_MII_BIT,
+};
+
+const int backplane_protocol_features_array[] = {
+ ETHTOOL_LINK_MODE_10000baseKR_Full_BIT,
+ ETHTOOL_LINK_MODE_40000baseKR4_Full_BIT,
+};
+
+/* map string key to pointer data */
+struct spmap_node {
+ struct list_head entry;
+ const char *key;
+ void *pdata;
+};
+
+/* registered equalization algorithms info */
+static LIST_HEAD(eqalg_list);
+
+/* lanes attached to an equalization algorithm */
+static LIST_HEAD(lnalg_list);
+
+/* Backplane mutex between all KR PHY threads */
+static struct mutex backplane_lock;
+
+static int get_backplane_speed(phy_interface_t interface)
+{
+ switch (interface) {
+ case PHY_INTERFACE_MODE_10GKR:
+ return SPEED_10000;
+ case PHY_INTERFACE_MODE_40GKR4:
+ return SPEED_40000;
+ default:
+ pr_err("%s: Unsupported backplane interface\n",
+ BACKPLANE_DRIVER_NAME);
+ return SPEED_UNKNOWN;
+ }
+ return SPEED_UNKNOWN;
+}
+
+static enum ethtool_link_mode_bit_indices
+ get_backplane_supported_mode(phy_interface_t interface)
+{
+ switch (interface) {
+ case PHY_INTERFACE_MODE_10GKR:
+ return ETHTOOL_LINK_MODE_10000baseKR_Full_BIT;
+ case PHY_INTERFACE_MODE_40GKR4:
+ return ETHTOOL_LINK_MODE_40000baseKR4_Full_BIT;
+ default:
+ pr_err("%s: Unsupported backplane interface\n",
+ BACKPLANE_DRIVER_NAME);
+ return ETHTOOL_LINK_MODE_Backplane_BIT;
+ }
+ return ETHTOOL_LINK_MODE_Backplane_BIT;
+}
+
+static int spmap_add(struct list_head *list, const char *key, void *pdata)
+{
+ struct spmap_node *node;
+
+ /* create a new entry with desired key */
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ if (!node)
+ return -ENOMEM;
+
+ node->key = key;
+ node->pdata = pdata;
+
+ list_add(&node->entry, list);
+
+ return 0;
+}
+
+static const struct equalization_algorithm *eq_find(const char *key)
+{
+ struct spmap_node *eqalg, *eqalg_tmp;
+
+ if (!key)
+ return NULL;
+
+ /* search desired single key */
+ list_for_each_entry_safe(eqalg, eqalg_tmp, &eqalg_list, entry) {
+ if (strcmp(eqalg->key, key) == 0)
+ return (struct equalization_algorithm *)eqalg->pdata;
+ }
+ return NULL;
+}
+
+static void backplane_features_init(void)
+{
+ linkmode_set_bit_array(backplane_common_features_array,
+ ARRAY_SIZE(backplane_common_features_array),
+ backplane_features);
+
+ linkmode_set_bit_array(backplane_protocol_features_array,
+ ARRAY_SIZE(backplane_protocol_features_array),
+ backplane_features);
+}
+
+static u32 le_ioread32(void __iomem *reg)
+{
+ return ioread32(reg);
+}
+
+static void le_iowrite32(u32 value, void __iomem *reg)
+{
+ iowrite32(value, reg);
+}
+
+static u32 be_ioread32(void __iomem *reg)
+{
+ return ioread32be(reg);
+}
+
+static void be_iowrite32(u32 value, void __iomem *reg)
+{
+ iowrite32be(value, reg);
+}
+
+static void training_status_init(struct training_status *trst)
+{
+ trst->done_training = false;
+ trst->remote_tx_complete = false;
+ trst->remote_tx_running = false;
+ trst->sent_init = false;
+ trst->lp_rx_ready = 0;
+ trst->local_tx_running = false;
+}
+
+static void init_kr_lane(struct lane_device *lane, bool revert_default)
+{
+ if (revert_default)
+ backplane_default_kr_lane(lane);
+
+ training_status_init(&lane->krln.trst);
+ lane->krln.state = DETECTING_LP;
+ lane->krln.an_kr_detected = false;
+
+ lane->krln.ld_update = 0;
+ lane->krln.prev_ld_update = 0;
+ lane->krln.ld_last_nonhold_update = 0;
+ lane->krln.lp_status = 0;
+ lane->krln.lp_last_change_status = 0;
+ lane->krln.last_lp_update_status[C_M1] = 0;
+ lane->krln.last_lp_update_status[C_Z0] = 0;
+ lane->krln.last_lp_update_status[C_P1] = 0;
+ lane->krln.ld_status = 0;
+ lane->krln.move_back_prev = false;
+ lane->krln.move_back_cnt = 0;
+ lane->krln.move_back_lp_status = 0;
+
+ lt_init_ld(lane);
+}
+
+static void setup_supported_linkmode(struct phy_device *phydev)
+{
+ int i;
+
+ /* Clear all supported backplane protocols features
+ * and setup only the currently configured protocol
+ */
+ for (i = 0; i < ARRAY_SIZE(backplane_protocol_features_array); i++)
+ linkmode_clear_bit(backplane_protocol_features_array[i],
+ phydev->supported);
+
+ linkmode_set_bit(get_backplane_supported_mode(phydev->interface),
+ phydev->supported);
+}
+
+/* Read AN Link Status */
+static int is_an_link_up(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev = phydev->priv;
+ int ret, val = 0;
+
+ mutex_lock(&bpdev->bpphy_lock);
+
+ /* Read twice because Link_Status is LL (Latched Low) bit */
+ val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_STAT1);
+ val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_STAT1);
+
+ mutex_unlock(&bpdev->bpphy_lock);
+
+ ret = (val & AN_LINK_UP_MASK) ? 1 : 0;
+
+ return ret;
+}
+
+static void start_kr_state_machine(struct lane_device *lane, u32 timeout)
+{
+ /* Check if equalization algorithm is installed */
+ if (!lane->krln.eq_alg)
+ return;
+
+ /* Check if link training is used */
+ if (!lane->krln.eq_alg->use_local_tx_training &&
+ !lane->krln.eq_alg->use_remote_tx_training)
+ return;
+
+ queue_delayed_work(system_power_efficient_wq, &lane->krwk,
+ msecs_to_jiffies(timeout));
+}
+
+static void stop_kr_state_machine(struct lane_device *lane)
+{
+ /* Check if equalization algorithm is installed */
+ if (!lane->krln.eq_alg)
+ return;
+
+ /* Check if link training is used */
+ if (!lane->krln.eq_alg->use_local_tx_training &&
+ !lane->krln.eq_alg->use_remote_tx_training)
+ return;
+
+ cancel_delayed_work_sync(&lane->krwk);
+}
+
+static void setup_default_settings(struct lane_device *lane)
+{
+ if (lane->bpdev->bpkr.valid_eq_init)
+ lane->krln.def_kr = lane->bpdev->bpkr.def_kr;
+ else
+ lane->bpdev->drv.lane_ops->read_lane_kr(lane->reg_base,
+ &lane->krln.def_kr);
+
+ /* HW specific default settings */
+ if (lane->bpdev->drv.bp_ops.setup_default_settings)
+ lane->bpdev->drv.bp_ops.setup_default_settings(lane);
+}
+
+static void kr_reset_master_lane(struct lane_device *lane)
+{
+ const struct lane_ops *lane_ops = lane->bpdev->drv.lane_ops;
+ struct backplane_device *bpdev = lane->bpdev;
+
+ if (backplane_is_multi_lane(bpdev)) {
+ /* Reset only the Master Lane */
+ if (lane->idx == MASTER_LANE)
+ lane_ops->reset_lane(lane->reg_base, LANE_RX_TX);
+ } else {
+ lane_ops->reset_lane(lane->reg_base, LANE_RX_TX);
+ }
+}
+
+static void print_single_lane_trained(struct lane_device *lane)
+{
+ struct phy_device *phydev = lane->phydev;
+
+ bpdev_info(phydev,
+ "%s link trained, Tx equalization: C(-1)=0x%x, C(0)=0x%x, C(+1)=0x%x\n",
+ phy_modes(phydev->interface),
+ lane->krln.tuned_kr.preq, lane->krln.tuned_kr.mainq,
+ lane->krln.tuned_kr.postq);
+}
+
+static void print_multi_lane_trained(struct lane_device *lane)
+{
+ struct backplane_device *bpdev = lane->bpdev;
+ struct phy_device *phydev = lane->phydev;
+ int i;
+
+ bpdev_info(phydev,
+ "%s link trained, Tx equalization:\n",
+ phy_modes(phydev->interface));
+
+ for (i = 0; i < bpdev->num_lanes; i++)
+ bpdev_info(phydev,
+ "\t|- Lane %d: C(-1)=0x%x, C(0)=0x%x, C(+1)=0x%x\n",
+ i + 1, bpdev->lane[i].krln.tuned_kr.preq,
+ bpdev->lane[i].krln.tuned_kr.mainq,
+ bpdev->lane[i].krln.tuned_kr.postq);
+}
+
+static void kr_link_trained(struct lane_device *lane)
+{
+ struct backplane_device *bpdev = lane->bpdev;
+
+ mutex_lock(&bpdev->trained_lock);
+ /* Setup lane state as TRAINED inside the phy trained lock
+ * to avoid duplicated message printed on multi-lane PHYs
+ */
+ lane->krln.state = TRAINED;
+
+ mutex_lock(&backplane_lock);
+
+ if (backplane_is_single_lane(bpdev))
+ print_single_lane_trained(lane);
+ else
+ if (backplane_are_all_lanes_trained(bpdev))
+ print_multi_lane_trained(lane);
+
+ mutex_unlock(&backplane_lock);
+ mutex_unlock(&bpdev->trained_lock);
+}
+
+static void kr_train_step(struct lane_device *lane)
+{
+ struct training_status *trst = &lane->krln.trst;
+ u32 lt_timeout = KR_LT_TIMEOUT;
+ u64 dead_line;
+ int i = 0;
+
+ /* Check if equalization algorithm is installed */
+ if (!lane->krln.eq_alg)
+ return;
+
+ /* Check if link training is used */
+ if (!lane->krln.eq_alg->use_local_tx_training &&
+ !lane->krln.eq_alg->use_remote_tx_training)
+ return;
+
+ lt_start(lane);
+
+ while (i < KR_TRAIN_STEP_ITERATIONS) {
+ dead_line = jiffies + msecs_to_jiffies(lt_timeout);
+ while (time_before(jiffies, (unsigned long)dead_line)) {
+ /* check if the LT is already failed */
+ if (lt_is_training_failure(lane)) {
+ /* LT failed already, reset lane to avoid
+ * it run into hanging, then start LT again.
+ */
+ kr_reset_master_lane(lane);
+ lt_start(lane);
+ } else if (lt_is_frame_lock(lane)) {
+ break;
+ }
+ /* wait frame lock (without training_failure) */
+ usleep_range(100, 500);
+ }
+
+ if (!lt_is_frame_lock(lane)) {
+ i++;
+ continue;
+ }
+
+ /* the LT should be finished in 500ms, failed or OK. */
+ dead_line = jiffies + msecs_to_jiffies(lt_timeout);
+ while (time_before(jiffies, (unsigned long)dead_line)) {
+ /* check if the LT is already failed */
+ if (lt_is_training_failure(lane)) {
+ kr_reset_master_lane(lane);
+ break;
+ }
+
+ if (lane->krln.eq_alg->use_local_tx_training)
+ lt_train_local_tx(lane);
+
+ if (lane->krln.eq_alg->use_remote_tx_training)
+ lt_train_remote_tx(lane);
+
+ if (lane->krln.lt_error)
+ break;
+
+ if (trst->lp_rx_ready && trst->remote_tx_complete)
+ break;
+
+ usleep_range(100, 500);
+ }
+
+ i++;
+ /* check if LT Error occurred */
+ if (lane->krln.lt_error) {
+ init_kr_lane(lane, false);
+ continue;
+ } else {
+ break;
+ }
+ }
+
+ lt_stop(lane);
+
+ /* check if Link is successfully TRAINED */
+ if (lt_is_rx_trained(lane))
+ kr_link_trained(lane);
+ else
+ kr_reset_master_lane(lane);
+}
+
+static void an_init(struct lane_device *masterln)
+{
+ struct backplane_device *bpdev = masterln->bpdev;
+ struct phy_device *phydev = masterln->phydev;
+ struct lane_device *lane;
+ u32 init_an_adv1;
+ int i, err;
+
+ if (!backplane_is_mode_kr(phydev->interface))
+ return;
+
+ if (masterln->idx != MASTER_LANE)
+ return;
+
+ init_an_adv1 = backplane_get_an_adv1_init(phydev->interface);
+
+ /* setup AN init on each lane */
+ for (i = 0; i < bpdev->num_lanes; i++) {
+ lane = &bpdev->lane[i];
+ if (bpdev->drv.bp_ops.an_advertisement_init) {
+ bpdev->drv.bp_ops.an_advertisement_init(lane);
+ } else {
+ err = backplane_write_mmd(lane, MDIO_MMD_AN,
+ AN_ADVERTISEMENT_1,
+ init_an_adv1);
+ if (err)
+ bpdev_err(phydev,
+ "Setting AN register 0x%02x on lane %d failed with error code: 0x%08x\n",
+ AN_ADVERTISEMENT_1, lane->idx, err);
+ }
+ }
+
+ udelay(1);
+
+ err = backplane_write_mmd(masterln, MDIO_MMD_AN, MDIO_CTRL1,
+ AN_CTRL_INIT);
+ if (err)
+ bpdev_err(phydev,
+ "Setting AN register 0x%02x on Master Lane failed with error code: 0x%08x\n",
+ MDIO_CTRL1, err);
+}
+
+static void an_request_restart(struct lane_device *lane)
+{
+ const struct lane_ops *lane_ops = lane->bpdev->drv.lane_ops;
+ struct backplane_device *bpdev = lane->bpdev;
+ struct phy_device *phydev = lane->phydev;
+ int i;
+
+ if (time_before(jiffies, (unsigned long)lane->krln.an_kr_timeout))
+ return;
+ if (!backplane_is_mode_kr(phydev->interface))
+ return;
+
+ for (i = 0; i < bpdev->num_lanes; i++) {
+ init_kr_lane(&bpdev->lane[i], true);
+ /* Reset the lane to recover from link down */
+ lane_ops->reset_lane(bpdev->lane[i].reg_base, LANE_RX_TX);
+ lt_reset(&bpdev->lane[i]);
+ }
+ /* AN init only for Master Lane */
+ an_init(&bpdev->lane[MASTER_LANE]);
+
+ lane->krln.an_kr_timeout = jiffies + msecs_to_jiffies(KR_AN_TIMEOUT);
+}
+
+static bool detect_lp(struct lane_device *lane)
+{
+ struct backplane_device *bpdev = lane->bpdev;
+ struct phy_device *phydev = lane->phydev;
+ struct lane_device *masterln;
+ bool start_train = false;
+ bool an_kr_link;
+ int an_state;
+ u32 an_mask;
+
+ if (bpdev->drv.bp_ops.is_an_link_detected) {
+ an_kr_link = bpdev->drv.bp_ops.is_an_link_detected(lane);
+ } else {
+ /* Check AN state only on Master Lane */
+ masterln = &bpdev->lane[MASTER_LANE];
+ an_mask = backplane_get_an_bp_eth_status_bit(phydev->interface);
+ an_state = backplane_read_mmd(masterln, MDIO_MMD_AN,
+ AN_BP_ETH_STATUS);
+ an_kr_link = an_state & an_mask;
+ }
+
+ /* The link training occurs after auto-negotiation
+ * has determined the link to be a Base-KR link.
+ * This is indicated by asserting the corresponding bit.
+ * This occurs before auto-negotiation can declare auto-negotiation
+ * complete, as this requires the PCS to report a valid link.
+ */
+ if (an_kr_link) {
+ /* AN acquired:
+ * Train all lanes in order starting with Master Lane
+ */
+ lane->krln.an_kr_detected = true;
+ lane->krln.an_kr_wait_count = 0;
+ start_train = true;
+ } else {
+ /* AN lost or not yet acquired */
+ if (lane->krln.an_kr_detected) {
+ /* AN acquired first time but now was lost */
+ if (!backplane_is_link_up(phydev)) {
+ /* Link is down: restart training */
+ lane->krln.an_kr_wait_count = 0;
+ an_request_restart(lane);
+ } else {
+ /* Link is up:
+ * wait few iterations for AN to be acquired
+ */
+ if (lane->krln.an_kr_wait_count >=
+ KR_AN_WAIT_ITERATIONS) {
+ lane->krln.an_kr_wait_count = 0;
+ an_request_restart(lane);
+ } else {
+ lane->krln.an_kr_wait_count++;
+ }
+ }
+ }
+ /* else: AN was not yet acquired first time
+ * DO nothing, just wait AN to be acquired first time
+ */
+ }
+
+ return start_train;
+}
+
+static void detect_hotplug(struct lane_device *lane)
+{
+ struct backplane_device *bpdev = lane->bpdev;
+ struct phy_device *phydev = lane->phydev;
+ int i;
+
+ if (lane->idx == MASTER_LANE) {
+ /* check if all lanes are trained
+ * only if current lane is Master Lane
+ */
+ if (backplane_are_all_lanes_trained(bpdev)) {
+ bpdev_info(phydev, "Detect hotplug, restart training\n");
+ for (i = 0; i < bpdev->num_lanes; i++) {
+ /* initializations on Detect hotplug / restart:
+ * they must not be part of init_kr_lane
+ */
+ bpdev->lane[i].krln.first_recv_init = false;
+ }
+ an_request_restart(lane);
+ }
+ }
+}
+
+static void bp_kr_state_machine(struct work_struct *work)
+{
+ struct delayed_work *dwork = to_delayed_work(work);
+ struct backplane_device *bpdev;
+ u32 kr_timeout = KR_TIMEOUT_1;
+ struct phy_device *phydev;
+ struct lane_device *lane;
+ bool start_train = false;
+
+ lane = container_of(dwork, struct lane_device, krwk);
+ if (!lane)
+ return;
+
+ bpdev = lane->bpdev;
+ phydev = lane->phydev;
+
+ if (!backplane_is_mode_kr(phydev->interface))
+ return;
+
+ /* Check if equalization algorithm is installed */
+ if (!lane->krln.eq_alg)
+ return;
+
+ /* Check if link training is used */
+ if (!lane->krln.eq_alg->use_local_tx_training &&
+ !lane->krln.eq_alg->use_remote_tx_training)
+ return;
+
+ mutex_lock(&lane->lane_lock);
+ switch (lane->krln.state) {
+ case DETECTING_LP:
+ start_train = detect_lp(lane);
+ break;
+ case TRAINED:
+ kr_timeout = KR_TIMEOUT_2;
+ if (!backplane_is_link_up(phydev)) {
+ kr_timeout = KR_TIMEOUT_1;
+ detect_hotplug(lane);
+ }
+ break;
+ }
+
+ if (start_train)
+ kr_train_step(lane);
+
+ mutex_unlock(&lane->lane_lock);
+ start_kr_state_machine(lane, kr_timeout);
+}
+
+static void init_kr_state_machine(struct lane_device *lane)
+{
+ /* Check if equalization algorithm is installed */
+ if (!lane->krln.eq_alg)
+ return;
+
+ /* Check if link training is used */
+ if (!lane->krln.eq_alg->use_local_tx_training &&
+ !lane->krln.eq_alg->use_remote_tx_training)
+ return;
+
+ INIT_DELAYED_WORK(&lane->krwk, bp_kr_state_machine);
+}
+
+/* backplane_get_current_taps
+ * convert coefficient taps from internal backplane driver to link training
+ */
+void backplane_get_current_taps(struct lane_device *lane, u32 *coef)
+{
+ coef[C_M1] = lane->krln.crt_kr.preq;
+ coef[C_Z0] = lane->krln.crt_kr.mainq;
+ coef[C_P1] = lane->krln.crt_kr.postq;
+}
+
+/* backplane_set_current_taps
+ * convert coefficient taps from link training to internal backplane driver
+ */
+void backplane_set_current_taps(struct lane_device *lane, u32 *coef)
+{
+ lane->krln.crt_kr.preq = coef[C_M1];
+ lane->krln.crt_kr.mainq = coef[C_Z0];
+ lane->krln.crt_kr.postq = coef[C_P1];
+}
+
+/* backplane_set_all_taps_to_max
+ * setup all coefficients to MAX values from IEEE802.3ap perspective
+ */
+void backplane_set_all_taps_to_max(struct lane_device *lane)
+{
+ lane->krln.crt_kr = lane->bpdev->bpkr.max_kr;
+}
+
+void backplane_tune_kr_lane(struct lane_device *lane, bool reset_lane)
+{
+ struct backplane_device *bpdev = lane->bpdev;
+ bool reset = false;
+
+ if (backplane_is_multi_lane(bpdev)) {
+ /* Reset only the Master Lane */
+ reset = (lane->idx == MASTER_LANE);
+ } else {
+ reset = true;
+ }
+
+ /* Do not reset the lane if this is how it was asked */
+ if (!reset_lane)
+ reset = false;
+
+ lane->bpdev->drv.lane_ops->tune_lane_kr(lane->reg_base,
+ &lane->krln.crt_kr, reset);
+ lane->krln.tuned_kr = lane->krln.crt_kr;
+}
+
+void backplane_default_kr_lane(struct lane_device *lane)
+{
+ lane->krln.crt_kr = lane->krln.def_kr;
+
+ backplane_tune_kr_lane(lane, true);
+}
+
+/* backplane_write_mmd - Wrapper function for phy_write_mmd
+ * for writing a register on an MMD on a given PHY.
+ *
+ * Same rules as for phy_write_mmd();
+ */
+int backplane_write_mmd(struct lane_device *lane, int devad, u32 regnum,
+ u16 val)
+{
+ struct backplane_device *bpdev = lane->bpdev;
+ struct phy_device *phydev = lane->phydev;
+ int mdio_addr = phydev->mdio.addr;
+ int err;
+
+ mutex_lock(&bpdev->bpphy_lock);
+
+ if (devad == MDIO_MMD_AN && backplane_is_multi_lane(bpdev)) {
+ /* Multilane AN: prepare mdio address
+ * for writing phydev AN registers on respective lane
+ * AN MDIO address offset for multilane is equal
+ * to number of lanes
+ */
+ phydev->mdio.addr = bpdev->num_lanes + lane->idx;
+ }
+
+ err = phy_write_mmd(phydev, devad, regnum, val);
+ if (err)
+ bpdev_err(phydev,
+ "Writing PHY (%p) MMD = 0x%02x register = 0x%02x failed with error code: 0x%08x\n",
+ phydev, devad, regnum, err);
+
+ if (devad == MDIO_MMD_AN && backplane_is_multi_lane(bpdev)) {
+ /* Multilane AN: restore mdio address */
+ phydev->mdio.addr = mdio_addr;
+ }
+
+ mutex_unlock(&bpdev->bpphy_lock);
+
+ return err;
+}
+EXPORT_SYMBOL(backplane_write_mmd);
+
+/* backplane_read_mmd - Wrapper function for phy_read_mmd
+ * for reading a register from an MMD on a given PHY.
+ *
+ * Same rules as for phy_read_mmd();
+ */
+int backplane_read_mmd(struct lane_device *lane, int devad, u32 regnum)
+{
+ struct backplane_device *bpdev = lane->bpdev;
+ struct phy_device *phydev = lane->phydev;
+ int mdio_addr = phydev->mdio.addr;
+ int ret;
+
+ mutex_lock(&bpdev->bpphy_lock);
+
+ if (devad == MDIO_MMD_AN && backplane_is_multi_lane(bpdev)) {
+ /* Multilane AN: prepare mdio address
+ * for reading phydev AN registers on respective lane
+ * AN MDIO address offset for multilane is equal to
+ * number of lanes
+ */
+ phydev->mdio.addr = bpdev->num_lanes + lane->idx;
+ }
+
+ ret = phy_read_mmd(phydev, devad, regnum);
+
+ if (devad == MDIO_MMD_AN && backplane_is_multi_lane(bpdev)) {
+ /* Multilane AN: restore mdio address */
+ phydev->mdio.addr = mdio_addr;
+ }
+
+ mutex_unlock(&bpdev->bpphy_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(backplane_read_mmd);
+
+/* backplane_eq_register
+ *
+ * Registers an equalization algorithm with the specified key
+ *
+ * key: desired key on which eq algorithm must be registered
+ * eq_info: eq algorithm information to be registered
+ *
+ * Returns: Zero for success or error code in case of failure
+ */
+int backplane_eq_register(const char *key,
+ const struct equalization_algorithm *eq_info)
+{
+ struct spmap_node *eqalg, *eqalg_tmp;
+
+ /* check if desired key already exists */
+ list_for_each_entry_safe(eqalg, eqalg_tmp, &eqalg_list, entry) {
+ if (strcmp(eqalg->key, key) == 0) {
+ pr_err("%s: Equalization algorithm registration failed: key '%s' already exists\n",
+ BACKPLANE_DRIVER_NAME, key);
+ return -EEXIST;
+ }
+ }
+
+ spmap_add(&eqalg_list, key, (void *)eq_info);
+
+ return 0;
+}
+EXPORT_SYMBOL(backplane_eq_register);
+
+/* backplane_eq_unregister
+ *
+ * Unregisters all equalization algorithm for the specified key
+ *
+ * key: desired key for which all registered eq algorithms must be removed
+ *
+ * Returns: None
+ */
+void backplane_eq_unregister(const char *key)
+{
+ const struct equalization_algorithm *eq_alg;
+ struct spmap_node *node, *node_tmp;
+ struct lane_device *lane;
+
+ if (!key)
+ return;
+
+ /* search all keys in lanes list */
+ list_for_each_entry_safe(node, node_tmp, &lnalg_list, entry) {
+ if (strcmp(node->key, key) == 0) {
+ lane = (struct lane_device *)node->pdata;
+ eq_alg = lane->krln.eq_alg;
+ if (eq_alg->ops.destroy)
+ eq_alg->ops.destroy(lane->krln.eq_priv);
+ lane->krln.eq_alg = NULL;
+ lane->krln.eq_priv = NULL;
+ list_del_init(&node->entry);
+ kfree(node);
+ }
+ }
+
+ /* search single key in eq algorithms list */
+ list_for_each_entry_safe(node, node_tmp, &eqalg_list, entry) {
+ if (strcmp(node->key, key) == 0) {
+ list_del_init(&node->entry);
+ kfree(node);
+ break;
+ }
+ }
+}
+EXPORT_SYMBOL(backplane_eq_unregister);
+
+bool backplane_is_mode_kr(phy_interface_t interface)
+{
+ return (interface >= PHY_INTERFACE_MODE_10GKR &&
+ interface <= PHY_INTERFACE_MODE_40GKR4);
+}
+EXPORT_SYMBOL(backplane_is_mode_kr);
+
+bool backplane_is_valid_mode(phy_interface_t interface)
+{
+ return (interface >= PHY_INTERFACE_MODE_10GKR &&
+ interface <= PHY_INTERFACE_MODE_40GKR4);
+}
+EXPORT_SYMBOL(backplane_is_valid_mode);
+
+u8 backplane_num_lanes(phy_interface_t interface)
+{
+ const char *bp_name;
+ char num_lanes;
+ int len;
+
+ if (!backplane_is_valid_mode(interface))
+ return 0;
+
+ bp_name = phy_modes(interface);
+ if (!bp_name)
+ return 0;
+ if (strcmp(bp_name, "unknown") == 0)
+ return 0;
+
+ len = strlen(bp_name);
+ if (len == 0)
+ return 0;
+ num_lanes = bp_name[len - 1];
+ if (num_lanes >= '0' && num_lanes <= '9')
+ return num_lanes - '0';
+
+ return 1;
+}
+EXPORT_SYMBOL(backplane_num_lanes);
+
+/* Backplane Ethernet Status Register Register 7.48 (an_bp_eth_status)
+ * - AN_MASK_10GBASE_KR for 10GBase-KR
+ * - AN_MASK_40GBASE_KR4 for 40GBase-KR4
+ */
+u32 backplane_get_an_bp_eth_status_bit(phy_interface_t interface)
+{
+ switch (interface) {
+ case PHY_INTERFACE_MODE_10GKR:
+ return AN_MASK_10GBASE_KR;
+ case PHY_INTERFACE_MODE_40GKR4:
+ return AN_MASK_40GBASE_KR4;
+ /* add AN support for other backplane modes here */
+ default:
+ pr_err("%s: Unsupported backplane interface\n",
+ BACKPLANE_DRIVER_NAME);
+ return 0;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(backplane_get_an_bp_eth_status_bit);
+
+u32 backplane_get_an_adv1_init(phy_interface_t interface)
+{
+ switch (interface) {
+ case PHY_INTERFACE_MODE_10GKR:
+ return AN_ADV1_KR_INIT_10G;
+ case PHY_INTERFACE_MODE_40GKR4:
+ return AN_ADV1_KR_INIT_40G;
+ /* add AN support for other backplane modes here */
+ default:
+ pr_err("%s: Unsupported backplane interface\n",
+ BACKPLANE_DRIVER_NAME);
+ return 0;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(backplane_get_an_adv1_init);
+
+void backplane_kr_lt_mmd_c45(struct backplane_kr *bpkr)
+{
+ lt_mmd_c45(bpkr);
+}
+EXPORT_SYMBOL(backplane_kr_lt_mmd_c45);
+
+void backplane_kr_lt_mmd_setup(struct backplane_kr *bpkr, int devad, u32 base)
+{
+ lt_mmd_setup(bpkr, devad, base);
+}
+EXPORT_SYMBOL(backplane_kr_lt_mmd_setup);
+
+bool backplane_is_single_lane(struct backplane_device *bpdev)
+{
+ return (bpdev->num_lanes == 1);
+}
+EXPORT_SYMBOL(backplane_is_single_lane);
+
+bool backplane_is_multi_lane(struct backplane_device *bpdev)
+{
+ return (bpdev->num_lanes > 1);
+}
+EXPORT_SYMBOL(backplane_is_multi_lane);
+
+/* backplane_is_cdr_lock
+ *
+ * Checks clock and data recovery bit: CDR Lock
+ *
+ * lane: desired lane to be verified
+ * retry: boolean value that specifies if to retry the check
+ *
+ * Returns: true if CDR_Lock bit is asserted or false otherwise
+ */
+bool backplane_is_cdr_lock(struct lane_device *lane, bool retry)
+{
+ const struct lane_ops *lane_ops = lane->bpdev->drv.lane_ops;
+ int i;
+
+ if (lane_ops->is_cdr_lock(lane->reg_base))
+ return true;
+
+ if (!retry)
+ return false;
+
+ /* Try RX_RESET: Allow for few retries */
+ for (i = 0; i < CDR_LOCK_RETRY_COUNT; i++) {
+ lane_ops->reset_lane(lane->reg_base, LANE_RX);
+ usleep_range(10, 50);
+
+ if (lane_ops->is_cdr_lock(lane->reg_base))
+ return true;
+ }
+ return false;
+}
+EXPORT_SYMBOL(backplane_is_cdr_lock);
+
+/* backplane_is_link_up
+ * Generic Link-up Status: use AN link-up
+ */
+int backplane_is_link_up(struct phy_device *phydev)
+{
+ return is_an_link_up(phydev);
+}
+EXPORT_SYMBOL(backplane_is_link_up);
+
+int backplane_get_lanes_trained_count(struct backplane_device *bpdev)
+{
+ int i, lanes_trained = 0;
+
+ for (i = 0; i < bpdev->num_lanes; i++) {
+ if (bpdev->lane[i].krln.state == TRAINED)
+ lanes_trained++;
+ }
+ return lanes_trained;
+}
+EXPORT_SYMBOL(backplane_get_lanes_trained_count);
+
+int backplane_are_all_lanes_trained(struct backplane_device *bpdev)
+{
+ int i;
+
+ for (i = 0; i < bpdev->num_lanes; i++) {
+ if (bpdev->lane[i].krln.state != TRAINED)
+ return 0;
+ }
+ return 1;
+}
+EXPORT_SYMBOL(backplane_are_all_lanes_trained);
+
+int backplane_create(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev;
+ struct device_node *dev_node;
+
+ dev_node = phydev->mdio.dev.of_node;
+ if (!dev_node) {
+ bpdev_err(phydev, "No associated device tree node\n");
+ return -EINVAL;
+ }
+
+ /* allocate memory for backplane info structure */
+ bpdev = devm_kzalloc(&phydev->mdio.dev, sizeof(*bpdev), GFP_KERNEL);
+ if (!bpdev)
+ return -ENOMEM;
+
+ bpdev->phydev = phydev;
+
+ /* save bpdev as phy private data pointer */
+ phydev->priv = bpdev;
+
+ return 0;
+}
+EXPORT_SYMBOL(backplane_create);
+
+/* backplane_parse_dt
+ * parses the device tree and saves backplane relevant data
+ * in backplane phy info structure
+ */
+int backplane_parse_dt(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev = phydev->priv;
+ struct device_node *dev_node;
+ u32 eqinit[C_NO];
+ const char *eqa;
+ int proplen;
+ int ret;
+
+ if (!bpdev) {
+ bpdev_err(phydev, "Backplane phy info is not allocated\n");
+ return -EINVAL;
+ }
+
+ dev_node = phydev->mdio.dev.of_node;
+ if (!dev_node) {
+ bpdev_err(phydev, "No associated device tree node\n");
+ return -EINVAL;
+ }
+
+ if (!backplane_is_valid_mode(phydev->interface))
+ return -EINVAL;
+
+ ret = of_property_read_string(dev_node, "eq-algorithm", &eqa);
+ /* if eq-algorithm node is not found then use the default algorithm */
+ if (ret == 0)
+ bpdev->bpkr.eqa_name = eqa;
+ else
+ bpdev->bpkr.eqa_name = DEFAULT_EQ_ALGORITHM;
+
+ /* if eq-init node exists then use the DTS specified values
+ * if eq-init node doesn't exist then use values already found in HW
+ */
+ proplen = of_property_count_u32_elems(dev_node, "eq-init");
+ if (proplen > 0) {
+ /* There are 3 standard equalization coefficient taps */
+ if (proplen > C_NO)
+ proplen = C_NO;
+ ret = of_property_read_u32_array(dev_node, "eq-init",
+ (u32 *)eqinit, proplen);
+ if (ret == 0) {
+ bpdev->bpkr.valid_eq_init = true;
+ bpdev->bpkr.def_kr.preq = eqinit[C_M1];
+ bpdev->bpkr.def_kr.mainq = eqinit[C_Z0];
+ bpdev->bpkr.def_kr.postq = eqinit[C_P1];
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(backplane_parse_dt);
+
+/* backplane_setup_memio
+ * Setup memory I/O access
+ */
+int backplane_setup_memio(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev = phydev->priv;
+
+ if (!bpdev) {
+ bpdev_err(phydev, "Backplane phy info is not allocated\n");
+ return -EINVAL;
+ }
+
+ /* setup ioread/iowrite according to endianness */
+ if (bpdev->drv.is_little_endian) {
+ bpdev->drv.io.read32 = le_ioread32;
+ bpdev->drv.io.write32 = le_iowrite32;
+ } else {
+ bpdev->drv.io.read32 = be_ioread32;
+ bpdev->drv.io.write32 = be_iowrite32;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(backplane_setup_memio);
+
+/* backplane_setup_mmd
+ * Setup default MMD (MDIO Managed Device)
+ */
+int backplane_setup_mmd(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev = phydev->priv;
+
+ if (!bpdev) {
+ bpdev_err(phydev, "Backplane phy info is not allocated\n");
+ return -EINVAL;
+ }
+
+ /* By default setup LT MMD Clause 45 */
+ backplane_kr_lt_mmd_c45(&bpdev->bpkr);
+
+ return 0;
+}
+EXPORT_SYMBOL(backplane_setup_mmd);
+
+/* backplane_setup_lanes
+ * Allocates lanes memory map and setup lanes relevant data
+ * Requires:
+ * - backplane_driver#lane_ops
+ * for lane access operations
+ * - backplane_driver#lane_ops#memmap_size
+ * for lane memory map allocation
+ * - backplane_kr#equalizer
+ * for specific Equalizer access
+ * - backplane_kr#cx_def
+ * for default coefficient setup
+ */
+int backplane_setup_lanes(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev = phydev->priv;
+ const struct equalization_algorithm *eq_alg;
+ struct equalizer_driver eqdrv;
+ struct lane_device *lane;
+ int i;
+
+ if (!bpdev) {
+ bpdev_err(phydev, "Backplane phy info is not allocated\n");
+ return -EINVAL;
+ }
+ if (!bpdev->drv.lane_ops) {
+ bpdev_err(phydev, "Backplane lane ops is not set\n");
+ return -EINVAL;
+ }
+ if (!bpdev->bpkr.equalizer) {
+ bpdev_err(phydev, "Backplane equalizer info is not set\n");
+ return -EINVAL;
+ }
+ if (bpdev->drv.lane_ops->memmap_size == 0) {
+ bpdev_err(phydev, "Lane memory map size is zero\n");
+ return -EINVAL;
+ }
+
+ bpdev->num_lanes = backplane_num_lanes(phydev->interface);
+
+ if (backplane_is_mode_kr(phydev->interface)) {
+ if (bpdev->bpkr.valid_eq_init &&
+ bpdev->bpkr.def_kr.preq == 0 &&
+ bpdev->bpkr.def_kr.mainq == 0 &&
+ bpdev->bpkr.def_kr.postq == 0)
+ bpdev_warn(phydev,
+ "All KR default values from DT are zero\n");
+ }
+
+ for (i = 0; i < bpdev->num_lanes; i++) {
+ lane = &bpdev->lane[i];
+
+ /* setup lane memory map size */
+ lane->memmap_size = bpdev->drv.lane_ops->memmap_size;
+
+ lane->reg_base = devm_ioremap(&phydev->mdio.dev,
+ lane->lane_addr,
+ lane->memmap_size);
+ if (!lane->reg_base) {
+ bpdev_err(phydev, "Lane memory map allocation failed\n");
+ return -ENOMEM;
+ }
+
+ lane->idx = i;
+ lane->phydev = phydev;
+ lane->bpdev = bpdev;
+ lane->krln.an_kr_timeout =
+ jiffies + msecs_to_jiffies(KR_AN_TIMEOUT);
+
+ if (backplane_is_mode_kr(phydev->interface)) {
+ setup_default_settings(lane);
+
+ /* Find EQ Algorithm info */
+ eq_alg = eq_find(bpdev->bpkr.eqa_name);
+ if (!eq_alg) {
+ /* key for desired algorithm was not found */
+ bpdev_err(phydev,
+ "Equalization algorithm '%s' is not registered\n",
+ bpdev->bpkr.eqa_name);
+ return -EINVAL;
+ }
+ if (!eq_alg->ops.create) {
+ bpdev_err(phydev,
+ "Equalization algorithm creation failed: create operation is not available\n");
+ return -EINVAL;
+ }
+ lane->krln.eq_alg = eq_alg;
+
+ /* Setup EQ Algorithm */
+ eqdrv.lane = lane;
+ eqdrv.phydev = lane->phydev;
+ eqdrv.reg_base = lane->reg_base;
+ eqdrv.equalizer = lane->bpdev->bpkr.equalizer;
+
+ /* Create EQ Algorithm */
+ lane->krln.eq_priv = eq_alg->ops.create(eqdrv);
+
+ /* register lane attached to an algorithm */
+ spmap_add(&lnalg_list, bpdev->bpkr.eqa_name, lane);
+
+ if (eq_alg->use_remote_tx_training) {
+ if (!eq_alg->ops.is_rx_ok)
+ bpdev_warn(phydev,
+ "Required operation for remote Tx training is missing: is_rx_ok\n");
+ if (!eq_alg->ops.is_eq_done)
+ bpdev_warn(phydev,
+ "Required operation for remote Tx training is missing: is_eq_done\n");
+ if (!eq_alg->ops.collect_statistics)
+ bpdev_warn(phydev,
+ "Required operation for remote Tx training is missing: collect_statistics\n");
+ if (!eq_alg->ops.generate_request)
+ bpdev_warn(phydev,
+ "Required operation for remote Tx training is missing: generate_request\n");
+ }
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(backplane_setup_lanes);
+
+/* backplane_initialize
+ * Initializes all PHY and lane mutexes and
+ * starts lane timers for running the algorithm
+ */
+int backplane_initialize(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev = phydev->priv;
+ int i;
+
+ if (!bpdev) {
+ bpdev_err(phydev, "Backplane phy info is not allocated\n");
+ return -EINVAL;
+ }
+
+ mutex_init(&bpdev->bpphy_lock);
+ mutex_init(&bpdev->trained_lock);
+
+ for (i = 0; i < bpdev->num_lanes; i++)
+ mutex_init(&bpdev->lane[i].lane_lock);
+
+ phydev->speed = get_backplane_speed(phydev->interface);
+ if (phydev->speed < 0) {
+ bpdev_err(phydev, "Unsupported backplane mode\n");
+ return -EINVAL;
+ }
+
+ if (backplane_is_mode_kr(phydev->interface)) {
+ for (i = 0; i < bpdev->num_lanes; i++)
+ init_kr_state_machine(&bpdev->lane[i]);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(backplane_initialize);
+
+/* backplane_probe
+ *
+ * Probe function for backplane driver to provide generic device behavior
+ *
+ * phydev: backplane phy device
+ * this is an internal phy block controlled by the software
+ * which contains other component blocks like: PMA/PMD, PCS, AN
+ *
+ * Return: Zero for success or error code in case of failure
+ */
+int backplane_probe(struct phy_device *phydev)
+{
+ return backplane_create(phydev);
+}
+EXPORT_SYMBOL(backplane_probe);
+
+void backplane_remove(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev = phydev->priv;
+
+ if (!bpdev) {
+ bpdev_err(phydev, "Backplane phy info is not allocated\n");
+ return;
+ }
+
+ kfree(bpdev);
+ phydev->priv = NULL;
+}
+EXPORT_SYMBOL(backplane_remove);
+
+/* backplane_config_init
+ *
+ * Config_Init function for backplane driver to provide generic device behavior
+ *
+ * phydev: backplane phy device
+ *
+ * Return: Zero for success or error code in case of failure
+ */
+int backplane_config_init(struct phy_device *phydev)
+{
+ int ret;
+
+ ret = backplane_parse_dt(phydev);
+ if (ret)
+ return ret;
+
+ ret = backplane_setup_memio(phydev);
+ if (ret)
+ return ret;
+
+ ret = backplane_setup_mmd(phydev);
+ if (ret)
+ return ret;
+
+ ret = backplane_setup_lanes(phydev);
+ if (ret)
+ return ret;
+
+ ret = backplane_initialize(phydev);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+EXPORT_SYMBOL(backplane_config_init);
+
+int backplane_aneg_done(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev = phydev->priv;
+
+ if (!phydev->mdio.dev.of_node) {
+ bpdev_err(phydev, "No associated device tree node\n");
+ return -EINVAL;
+ }
+ if (!bpdev) {
+ bpdev_err(phydev, "Backplane phy info is not allocated\n");
+ return -EINVAL;
+ }
+
+ bpdev->aneg_done = true;
+ phydev->state = PHY_RUNNING;
+
+ return 1;
+}
+EXPORT_SYMBOL(backplane_aneg_done);
+
+int backplane_config_aneg(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev = phydev->priv;
+ struct equalization_ops ops;
+ struct lane_device *lane;
+ int i;
+
+ if (!phydev->mdio.dev.of_node) {
+ bpdev_err(phydev, "No associated device tree node\n");
+ return -EINVAL;
+ }
+ if (!bpdev) {
+ bpdev_err(phydev, "Backplane phy info is not allocated\n");
+ return -EINVAL;
+ }
+ if (backplane_get_lanes_trained_count(bpdev) > 0) {
+ bpdev_err(phydev, "Incorrectly trained lanes detected\n");
+ return -EINVAL;
+ }
+
+ for (i = 0; i < bpdev->num_lanes; i++) {
+ lane = &bpdev->lane[i];
+ if (lane->krln.eq_alg) {
+ ops = lane->krln.eq_alg->ops;
+ if (ops.dump_algorithm_context)
+ ops.dump_algorithm_context(lane->krln.eq_priv);
+ }
+ }
+
+ if (backplane_is_mode_kr(phydev->interface)) {
+ /* Warning:
+ * Order of the operations below is important
+ * otherwise the training may be failing
+ * with error: 'link_training_failed'
+ */
+
+ /* setup all lanes to default */
+ for (i = 0; i < bpdev->num_lanes; i++)
+ setup_default_settings(&bpdev->lane[i]);
+
+ /* Initialize all lanes and reset LT */
+ for (i = 0; i < bpdev->num_lanes; i++) {
+ init_kr_lane(&bpdev->lane[i], true);
+ lt_reset(&bpdev->lane[i]);
+ }
+ }
+
+ /* Warning:
+ * speed and protocol setup operation
+ * must be done just before AN and state machine start
+ * otherwise if it is done earlier,
+ * the error: 'REQ Timeout' will occur
+ */
+ /* setup supported speed and protocol */
+ phydev->speed = get_backplane_speed(phydev->interface);
+ if (phydev->speed < 0) {
+ bpdev_err(phydev, "Unsupported backplane mode\n");
+ return -EINVAL;
+ }
+
+ setup_supported_linkmode(phydev);
+ linkmode_copy(phydev->advertising, phydev->supported);
+ phydev->duplex = DUPLEX_FULL;
+
+ if (backplane_is_mode_kr(phydev->interface)) {
+ /* AN init only for Master Lane */
+ an_init(&bpdev->lane[MASTER_LANE]);
+ /* start state machine on all lanes */
+ for (i = 0; i < bpdev->num_lanes; i++)
+ start_kr_state_machine(&bpdev->lane[i], KR_TIMEOUT_1);
+ }
+
+ bpdev->aneg_config = true;
+
+ return 0;
+}
+EXPORT_SYMBOL(backplane_config_aneg);
+
+int backplane_suspend(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev = phydev->priv;
+ int i;
+
+ if (!phydev->mdio.dev.of_node) {
+ bpdev_err(phydev, "No associated device tree node\n");
+ return -EINVAL;
+ }
+ if (!bpdev) {
+ bpdev_err(phydev, "Backplane phy info is not allocated\n");
+ return -EINVAL;
+ }
+
+ if (bpdev->aneg_config && !bpdev->phy_suspended) {
+ if (backplane_is_mode_kr(phydev->interface)) {
+ for (i = 0; i < bpdev->num_lanes; i++)
+ stop_kr_state_machine(&bpdev->lane[i]);
+ }
+ bpdev->phy_suspended = true;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(backplane_suspend);
+
+int backplane_resume(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev = phydev->priv;
+ int i;
+
+ if (!phydev->mdio.dev.of_node) {
+ bpdev_err(phydev, "No associated device tree node\n");
+ return -EINVAL;
+ }
+ if (!bpdev) {
+ bpdev_err(phydev, "Backplane phy info is not allocated\n");
+ return -EINVAL;
+ }
+
+ if (bpdev->aneg_config && bpdev->phy_suspended) {
+ if (backplane_is_mode_kr(phydev->interface)) {
+ for (i = 0; i < bpdev->num_lanes; i++) {
+ init_kr_lane(&bpdev->lane[i], true);
+ start_kr_state_machine(&bpdev->lane[i],
+ KR_TIMEOUT_1);
+ }
+ }
+ bpdev->phy_suspended = false;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(backplane_resume);
+
+int backplane_read_status(struct phy_device *phydev)
+{
+ struct backplane_device *bpdev = phydev->priv;
+
+ if (!phydev->mdio.dev.of_node) {
+ bpdev_err(phydev, "No associated device tree node\n");
+ return -EINVAL;
+ }
+ if (!bpdev) {
+ bpdev_err(phydev, "Backplane phy info is not allocated\n");
+ return -EINVAL;
+ }
+
+ /* Linkup method proposal for training stability:
+ * Don't raise linkup until all lanes are trained
+ * in order to prevent interface sending packets that may
+ * interfere with the training packets
+ */
+ if (backplane_is_link_up(phydev))
+ if (backplane_is_mode_kr(phydev->interface))
+ phydev->link = backplane_are_all_lanes_trained(bpdev);
+ else
+ phydev->link = 1;
+ else
+ phydev->link = 0;
+
+ return 0;
+}
+EXPORT_SYMBOL(backplane_read_status);
+
+int backplane_match_phy_device(struct phy_device *phydev)
+{
+ struct device_node *dev_node;
+
+ if (!phydev->is_c45)
+ return 0;
+
+ dev_node = phydev->mdio.dev.of_node;
+ if (!dev_node) {
+ bpdev_err(phydev, "No associated device tree node\n");
+ return 0;
+ }
+
+ return 1;
+}
+EXPORT_SYMBOL(backplane_match_phy_device);
+
+static int __init backplane_module_init(void)
+{
+ pr_info("%s: Backplane driver version %s\n",
+ BACKPLANE_DRIVER_NAME, BACKPLANE_DRIVER_VERSION);
+
+ mutex_init(&backplane_lock);
+ backplane_features_init();
+
+ return 0;
+}
+
+static void __exit backplane_module_exit(void)
+{
+ pr_info("%s: Backplane driver version %s unloaded\n",
+ BACKPLANE_DRIVER_NAME, BACKPLANE_DRIVER_VERSION);
+}
+
+module_init(backplane_module_init);
+module_exit(backplane_module_exit);
+
+MODULE_DESCRIPTION("Backplane driver");
+MODULE_AUTHOR("Florinel Iordache <florinel.iordache@xxxxxxx>");
+MODULE_LICENSE("Dual BSD/GPL");
diff --git a/drivers/net/phy/backplane/backplane.h b/drivers/net/phy/backplane/backplane.h
new file mode 100644
index 0000000..5705d16
--- /dev/null
+++ b/drivers/net/phy/backplane/backplane.h
@@ -0,0 +1,293 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) */
+/* Backplane driver
+ *
+ * Copyright 2018-2020 NXP
+ */
+
+#ifndef __BACKPLANE_H
+#define __BACKPLANE_H
+
+#include <linux/phy.h>
+#include <linux/mutex.h>
+
+#include "equalization.h"
+
+/* Backplane Driver name */
+#define BACKPLANE_DRIVER_NAME "backplane"
+
+/* Backplane Driver version */
+#define BACKPLANE_DRIVER_VERSION "1.0.0"
+
+/* Maximum number of lanes per phy */
+#define MAX_KR_LANES_PER_PHY 4
+
+/* Lanes definitions */
+#define MASTER_LANE 0
+#define SINGLE_LANE 0
+
+/* Number of device specific kr coefficients (device specific extension) */
+#define DEVICE_KR_COEF_NO 6
+
+extern __ETHTOOL_DECLARE_LINK_MODE_MASK(backplane_features) __ro_after_init;
+
+#define BACKPLANE_FEATURES ((unsigned long *)&backplane_features)
+
+enum train_state {
+ DETECTING_LP,
+ TRAINED,
+};
+
+enum lane_req {
+ LANE_INVALID,
+ LANE_RX,
+ LANE_TX,
+ LANE_RX_TX
+};
+
+struct kr_coef {
+ u32 preq;
+ u32 mainq;
+ u32 postq;
+ /* device specific extension */
+ u32 dev_coef[DEVICE_KR_COEF_NO];
+};
+
+/* Endianness specific memory I/O */
+struct mem_io {
+ u32 (*read32)(void __iomem *addr);
+ void (*write32)(u32 value, void __iomem *addr);
+};
+
+/* Generic Lane operations */
+struct lane_ops {
+ /* device specific private extension */
+ const void *priv;
+ /* lane memory map size */
+ u32 memmap_size;
+ void (*reset_lane)(void __iomem *reg, enum lane_req req);
+ void (*tune_lane_kr)(void __iomem *reg, struct kr_coef *coef,
+ bool reset);
+ void (*read_lane_kr)(void __iomem *reg, struct kr_coef *coef);
+ bool (*is_cdr_lock)(void __iomem *reg);
+};
+
+struct training_status {
+ bool done_training;
+ bool remote_tx_complete;
+ bool remote_tx_running;
+ bool sent_init;
+ bool lp_rx_ready;
+ bool local_tx_running;
+};
+
+struct backplane_device;
+
+/* Lane kr */
+struct lane_kr {
+ /* KR parameters (current, default, tuned) */
+ struct kr_coef crt_kr;
+ struct kr_coef def_kr;
+ struct kr_coef tuned_kr;
+ /* equalization */
+ const struct equalization_algorithm *eq_alg;
+ struct eq_data_priv *eq_priv;
+ /* training status */
+ struct training_status trst;
+ enum train_state state;
+ /* AN KR status */
+ bool an_kr_detected;
+ u32 an_kr_wait_count;
+ u64 an_kr_timeout;
+ /* KR LD/LP updates and status */
+ u32 ld_update;
+ u32 prev_ld_update;
+ /* last change (non-hold) update */
+ u32 ld_last_nonhold_update;
+ u32 ld_status;
+ u32 lp_status;
+ /* last change (non-zero) status */
+ u32 lp_last_change_status;
+ u32 last_lp_update_status[C_NO];
+ /* link training status */
+ bool lt_error;
+ u32 req_ld_update_init_count;
+ u32 repeat_request_count;
+ u64 init_handshake_time;
+ bool first_recv_init;
+ /* move lp back */
+ bool move_back_prev;
+ u32 move_back_cnt;
+ u32 move_back_lp_status;
+};
+
+/* Lane device */
+struct lane_device {
+ /* lane memory map: registers base address */
+ void __iomem *reg_base;
+ /* lane memory map size */
+ u32 memmap_size;
+ /* lane address */
+ u32 lane_addr;
+ /* lane relative index inside multi-lane PHY */
+ u8 idx;
+ /* device specific private extension */
+ void *priv;
+ /* phy device */
+ struct phy_device *phydev;
+ struct backplane_device *bpdev;
+ struct lane_kr krln;
+ struct delayed_work krwk;
+ /* mutex between multiple lanes */
+ struct mutex lane_lock;
+};
+
+/* KR LT MMD (MDIO Managed Device) */
+struct kr_lt_mmd {
+ int devad;
+ u32 control;
+ u32 status;
+ u32 lp_cu;
+ u32 lp_status;
+ u32 ld_cu;
+ u32 ld_status;
+};
+
+/* Backplane kr */
+struct backplane_kr {
+ struct kr_coef min_kr;
+ struct kr_coef max_kr;
+ struct kr_coef def_kr;
+ /* defaults for eq kr are initialized from DT: eq-init */
+ bool valid_eq_init;
+ /* defaults for eq params are initialized from DT: eq-params */
+ bool valid_eq_params;
+ /* EQ algorithm name */
+ const char *eqa_name;
+ const struct equalizer_device *equalizer;
+ struct kr_lt_mmd ltmmd;
+};
+
+/* Backplane device specific callbacks */
+struct backplane_ops {
+ /* AN register ops */
+ void (*an_advertisement_init)(struct lane_device *lane);
+ bool (*is_an_link_detected)(struct lane_device *lane);
+ /* default settings ops */
+ void (*setup_default_settings)(struct lane_device *lane);
+ /* LT coefficients validation ops */
+ int (*lt_validation)(struct lane_device *lane, u32 *ld_coef);
+};
+
+/* Backplane driver */
+struct backplane_driver {
+ /* serdes base address */
+ u32 base_addr;
+ /* serdes memory map size */
+ u32 memmap_size;
+ /* serdes endianness */
+ bool is_little_endian;
+ /* memory I/O */
+ struct mem_io io;
+ /* backplane ops */
+ struct backplane_ops bp_ops;
+ /* lane ops */
+ const struct lane_ops *lane_ops;
+ /* device specific private extension */
+ void *priv;
+};
+
+/* Backplane device */
+struct backplane_device {
+ struct phy_device *phydev;
+ u8 num_lanes;
+ bool aneg_config;
+ bool aneg_done;
+ bool phy_suspended;
+ /* backplane management functions */
+ struct backplane_driver drv;
+ /* backplane kr */
+ struct backplane_kr bpkr;
+ /* kr lanes array: valid elements = num_lanes */
+ struct lane_device lane[MAX_KR_LANES_PER_PHY];
+ /* device specific private extension */
+ void *priv;
+ /* bpphy mutexes */
+ struct mutex bpphy_lock;
+ /* mutex between multiple lanes training */
+ struct mutex trained_lock;
+};
+
+bool backplane_is_mode_kr(phy_interface_t interface);
+
+bool backplane_is_valid_mode(phy_interface_t interface);
+
+u8 backplane_num_lanes(phy_interface_t interface);
+
+u32 backplane_get_an_bp_eth_status_bit(phy_interface_t interface);
+
+u32 backplane_get_an_adv1_init(phy_interface_t interface);
+
+bool backplane_is_single_lane(struct backplane_device *bpdev);
+
+bool backplane_is_multi_lane(struct backplane_device *bpdev);
+
+int backplane_are_all_lanes_trained(struct backplane_device *bpdev);
+
+int backplane_get_lanes_trained_count(struct backplane_device *bpdev);
+
+int backplane_is_link_up(struct phy_device *phydev);
+
+void backplane_kr_lt_mmd_c45(struct backplane_kr *bpkr);
+
+void backplane_kr_lt_mmd_setup(struct backplane_kr *bpkr, int devad, u32 base);
+
+int backplane_read_mmd(struct lane_device *lane, int devad, u32 regnum);
+
+int backplane_write_mmd(struct lane_device *lane, int devad, u32 regnum,
+ u16 val);
+
+void backplane_default_kr_lane(struct lane_device *lane);
+
+void backplane_get_current_taps(struct lane_device *lane, u32 *coef);
+
+void backplane_set_current_taps(struct lane_device *lane, u32 *coef);
+
+void backplane_set_all_taps_to_max(struct lane_device *lane);
+
+void backplane_tune_kr_lane(struct lane_device *lane, bool reset_lane);
+
+/* generic main operations to be used on probe callback */
+
+int backplane_create(struct phy_device *phydev);
+
+int backplane_parse_dt(struct phy_device *phydev);
+
+int backplane_setup_memio(struct phy_device *phydev);
+
+int backplane_setup_mmd(struct phy_device *phydev);
+
+int backplane_setup_lanes(struct phy_device *phydev);
+
+int backplane_initialize(struct phy_device *phydev);
+
+/* predefined phy_driver callback functions */
+
+int backplane_probe(struct phy_device *phydev);
+
+void backplane_remove(struct phy_device *phydev);
+
+int backplane_config_init(struct phy_device *phydev);
+
+int backplane_aneg_done(struct phy_device *phydev);
+
+int backplane_config_aneg(struct phy_device *phydev);
+
+int backplane_suspend(struct phy_device *phydev);
+
+int backplane_resume(struct phy_device *phydev);
+
+int backplane_read_status(struct phy_device *phydev);
+
+int backplane_match_phy_device(struct phy_device *phydev);
+
+#endif /* __BACKPLANE_H */
diff --git a/drivers/net/phy/backplane/eq_fixed.c b/drivers/net/phy/backplane/eq_fixed.c
new file mode 100644
index 0000000..827450e
--- /dev/null
+++ b/drivers/net/phy/backplane/eq_fixed.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/* Fixed: No Equalization algorithm
+ *
+ * Copyright 2019-2020 NXP
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "equalization.h"
+
+#define ALGORITHM_NAME "backplane_fixed"
+#define ALGORITHM_DESCR "Fixed Equalization"
+#define ALGORITHM_VERSION "1.0.0"
+
+/* Fixed Algorithm API */
+
+/* Create Fixed Equalization Algorithm */
+static struct eq_data_priv *create(struct equalizer_driver eqdrv)
+{
+ return NULL;
+}
+
+static const struct equalization_algorithm eq_alg = {
+ .name = ALGORITHM_NAME,
+ .descr = ALGORITHM_DESCR,
+ .version = ALGORITHM_VERSION,
+ .use_local_tx_training = false,
+ .use_remote_tx_training = false,
+ .ops = {
+ .create = create,
+ .destroy = NULL,
+ .is_rx_ok = NULL,
+ .is_eq_done = NULL,
+ .collect_statistics = NULL,
+ .generate_request = NULL,
+ .process_bad_state = NULL,
+ .dump_algorithm_context = NULL,
+ }
+};
+
+static const char * const alg_keys[] = {
+ DEFAULT_EQ_ALGORITHM,
+ "bypass",
+};
+
+static int __init fixed_init(void)
+{
+ int i, err;
+
+ pr_info("%s: %s algorithm version %s\n",
+ ALGORITHM_NAME, ALGORITHM_DESCR, ALGORITHM_VERSION);
+
+ /* register Fixed algorithm: */
+ for (i = 0; i < ARRAY_SIZE(alg_keys); i++) {
+ err = backplane_eq_register(alg_keys[i], &eq_alg);
+ if (err) {
+ pr_err("%s: '%s' equalization algorithm registration failed\n",
+ ALGORITHM_NAME, alg_keys[i]);
+ }
+ }
+
+ return 0;
+}
+
+static void __exit fixed_exit(void)
+{
+ int i;
+
+ /* unregister Fixed algorithm: */
+ for (i = 0; i < ARRAY_SIZE(alg_keys); i++)
+ backplane_eq_unregister(alg_keys[i]);
+
+ pr_info("%s: %s algorithm version %s unloaded\n",
+ ALGORITHM_NAME, ALGORITHM_DESCR, ALGORITHM_VERSION);
+}
+
+module_init(fixed_init);
+module_exit(fixed_exit);
+
+MODULE_DESCRIPTION("Fixed Equalization Algorithm");
+MODULE_AUTHOR("Florinel Iordache <florinel.iordache@xxxxxxx>");
+MODULE_LICENSE("Dual BSD/GPL");
diff --git a/drivers/net/phy/backplane/equalization.h b/drivers/net/phy/backplane/equalization.h
new file mode 100644
index 0000000..812c361
--- /dev/null
+++ b/drivers/net/phy/backplane/equalization.h
@@ -0,0 +1,283 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) */
+/* Equalization interface
+ * for Equalization and Link Training (IEEE802.3ap/ba)
+ *
+ * Copyright 2019-2020 NXP
+ */
+
+#ifndef __EQUALIZATION_H
+#define __EQUALIZATION_H
+
+#include <linux/phy.h>
+
+/* Default equalization algorithm */
+#define DEFAULT_EQ_ALGORITHM "fixed"
+
+struct lane_device;
+struct equalizer_driver;
+
+/* EQ Algorithms Interface used by Link Training
+ * to call equalization algorithms callbacks
+ */
+
+/* Equalization private data
+ * specifically defined by each algorithm to be used internally
+ */
+struct eq_data_priv;
+
+/* Equalization Algorithm operations */
+struct equalization_ops {
+ /* Mandatory operations: */
+ struct eq_data_priv *(*create)(struct equalizer_driver eqdrv);
+ void (*destroy)(struct eq_data_priv *priv);
+ /* Required operations for remote Tx link training: */
+ bool (*is_rx_ok)(struct eq_data_priv *priv);
+ bool (*is_eq_done)(struct eq_data_priv *priv);
+ bool (*collect_statistics)(struct eq_data_priv *priv);
+ void (*generate_request)(struct eq_data_priv *priv);
+ /* Optional operations: */
+ void (*process_bad_state)(struct eq_data_priv *priv);
+ void (*dump_algorithm_context)(struct eq_data_priv *priv);
+};
+
+/* Equalization Algorithm description data */
+struct equalization_algorithm {
+ const char *name;
+ const char *descr;
+ const char *version;
+ bool use_local_tx_training;
+ bool use_remote_tx_training;
+ struct equalization_ops ops;
+};
+
+/* Equalizer Interface for EQ Algorithms:
+ * Used by equalization algorithms to collect equalizer statistics
+ * required to take correct decisions for tuning equalization parameters
+ */
+
+/* Equalizer counters type
+ *
+ * Equalizer Binning Counters for Data Dependent Edge Statistics:
+ *
+ * Bin(s) = (# late edges - # early edges)
+ * Prior/Next Edge at T -/+ #UI (Unit Interval)
+ * Bin_1: 1UI wide pulses: Prior Edge at T - 1UI
+ * final edges on short pulses:
+ * - contains the scoring of final edges on pulses that are 1UI long
+ * - represents the difference between the number of short pulse late edges
+ * and the number of short pulse early edges
+ * Bin_2: 2UI wide pulses: Prior Edge at T - 2UI
+ * Bin_3: 3UI (or >=3UI) wide pulses: Prior Edge at T - 3UI (or T - >=3UI)
+ * Bin_4: 4UI (or >=4UI) wide pulses: Prior Edge at T - 4UI (or T - >=4UI)
+ * Bin_Med: >=5UI and <=7UI wide pulses:
+ * Prior Edge in between T - >=5UI and T - <=7UI
+ * final edges on medium pulses:
+ * - contains the scoring of final edges on pulses between 5UI and 7UI long
+ * Bin_Long: >=8UI wide pulses: Prior Edge at T - >=8UI
+ * final edges on long pulses:
+ * - contains the scoring of final edges on pulses longer than 7UI long
+ * - represents the difference between the number of long pulse late edges
+ * and the number of long pulse early edges
+ * Bin_M1: 1UI wide pulses: Next Edge at T + 1UI
+ * initial edges on short pulses following non-single bits:
+ * - contains the scoring of initial edges on pulses that are 1UI long
+ * following non-single bits
+ * - the next edge is 1UI away and prior edge is more than 1UI away
+ * Bin_M2: 2UI wide pulses: Next Edge at T + 2UI
+ * Bin_M3: 3UI (or >=3UI) wide pulses: Next Edge at T + 3UI (or T + >=3UI)
+ * Bin_M4: 4UI (or >=4UI) wide pulses: Next Edge at T + 4UI (or T + >=4UI)
+ * Bin_MMed: >=5UI and <=7UI wide pulses:
+ * Next Edge in between T + >=5UI and T + <=7UI
+ * initial edges on medium pulses following non-single bits:
+ * - contains the scoring of initial edges on pulses between 5UI and 7UI
+ * following non-single bits
+ * Bin_MLong: >=8UI wide pulses: Next Edge at T + >=8UI
+ * initial edges on long pulses following non-single bits:
+ * - contains the scoring of initial edges on pulses longer than 7UI long
+ * - represents the difference between the number of long pulse late edges
+ * and the number of long pulse early edges
+ *
+ * Bin_Offset = [(# late rising edges + # early falling edges) -
+ * (# early rising edges + # late falling edges)]
+ * - contains the transition information for the difference between
+ * all bits that are narrower than expected and
+ * all bits that are wider than expected
+ *
+ * Bin_Avg: Low Pass Filter of Running Disparity
+ * - Bin_Avg provides a time weighted, filtered average of disparity which
+ * indicates the BLW potential of recently received data
+ * New Bin_Avg = Bin_Avg - Bin_Avg/8 + block_disparity
+ * where block_disparity = (#of ones - #of zeros)
+ *
+ * Bin_BLW: Bin Baseline Wander
+ * - BinBLW accumulates the correlation between Bin_Avg and Bin_Offset
+ * - Low frequency deficiency (LFD) causes BLW effect
+ * New Bin_BLW = Bin_BLW + Bin_Avg, for Bin_Offset > 0
+ * = Bin_BLW - Bin_Avg, for Bin_Offset < 0
+ * = Bin_BLW, for Bin_Offset = 0
+ *
+ * Equalizer gains:
+ * GAIN_LF: Low-frequency gain of the equalizer amplifier
+ * GAIN_MF: Middle-frequency gain of the equalizer amplifier
+ * GAIN_HF: High-frequency gain of the equalizer amplifier
+ *
+ * Equalizer status:
+ * EQOFFSET: equalization offset status
+ * Binary coded status of RX Adaptive Equalization offset controls of lane
+ */
+enum eqc_type {
+ EQC_BIN_1,
+ EQC_BIN_2,
+ EQC_BIN_3,
+ EQC_BIN_4,
+ EQC_BIN_MED,
+ EQC_BIN_LONG,
+ EQC_BIN_M1,
+ EQC_BIN_M2,
+ EQC_BIN_M3,
+ EQC_BIN_M4,
+ EQC_BIN_MMED,
+ EQC_BIN_MLONG,
+ EQC_BIN_OFFSET,
+ EQC_BIN_AVG,
+ EQC_BIN_BLW,
+ EQC_GAIN_LF,
+ EQC_GAIN_MF,
+ EQC_GAIN_HF,
+ EQC_EQOFFSET,
+};
+
+/* Equalizer counters range */
+struct eqc_range {
+ s16 min;
+ s16 max;
+ s16 mid_low;
+ s16 mid_high;
+};
+
+/* Equalizer counters collection operations */
+struct equalizer_ops {
+ int (*collect_counters)(void *reg, enum eqc_type type, s16 *counters,
+ u8 size);
+ int (*collect_multiple_counters)(void *reg, enum eqc_type type[],
+ u8 type_no, s16 *counters, u8 size);
+ struct eqc_range *(*get_counter_range)(enum eqc_type type);
+};
+
+/* Equalizer device and operations */
+struct equalizer_device {
+ const char *name;
+ const char *version;
+ struct equalizer_ops ops;
+};
+
+/* Equalization driver */
+struct equalizer_driver {
+ struct phy_device *phydev;
+ /* lane info used as parameter for link training API */
+ struct lane_device *lane;
+ /* lane reg base used as parameter for equalizer ops */
+ void *reg_base;
+ const struct equalizer_device *equalizer;
+};
+
+/* Link Training Interface used by EQ Algorithms
+ * to interact with IEEE802.3ap/ba standards
+ */
+
+/* update request type
+ * Identifies the LP update request type according to IEEE802.3ap-2007
+ * which must be sent to LP to request coefficients update
+ *
+ * HOLD: Request LP to Hold all coefficients update
+ * INC: Request LP to Increment the specified coefficient
+ * DEC: Request LP to Decrement the specified coefficient
+ * INIT: Request LP to Initialize all coefficients
+ * PRESET: Request LP to set all coefficients to Preset
+ * INVALID: Invalid request type: should not be used as LP request
+ */
+enum req_type {
+ REQ_HOLD,
+ REQ_INC,
+ REQ_DEC,
+ REQ_INIT,
+ REQ_PRESET,
+ REQ_INVALID
+};
+
+/* coefficient field
+ * Identifies the coefficient field on which must take a desired action
+ * according to IEEE802.3ap-2007
+ *
+ * coefficients:
+ * M1: C(-1): Pre-cursor
+ * Z0: C(0): Main cursor
+ * P1: C(+1): Post-cursor
+ * NO: Number of coefficients (this is not a valid coefficient field)
+ */
+enum coef_field {
+ C_M1,
+ C_Z0,
+ C_P1,
+ C_NO
+};
+
+/* coefficient status
+ * Specifies the coefficient status according to IEEE802.3ap-2007:
+ * 72.6.10.2.5 Coefficient update process
+ *
+ * NOTUPDATED: Coefficient is not updated
+ * UPDATED: Coefficient is updated
+ * MIN: Coefficient has reached the minimum threshold
+ * MAX: Coefficient has reached the maximum threshold
+ * INVALID: Invalid coefficient status
+ */
+enum coef_status {
+ COEF_NOTUPDATED,
+ COEF_UPDATED,
+ COEF_MIN,
+ COEF_MAX,
+ COEF_INVALID
+};
+
+void lt_lp_update(struct lane_device *lane, u32 update);
+
+u32 lt_encode_request(u32 base_update, enum req_type req,
+ enum coef_field field);
+
+u32 lt_encode_startup_request(enum req_type req);
+
+enum req_type lt_decode_coef_update(u32 update, enum coef_field field);
+
+bool lt_is_update_of_type(u32 update, enum req_type type);
+
+bool lt_is_lp_at_startup(struct lane_device *lane, enum req_type type);
+
+enum coef_status lt_get_lp_coef_status(struct lane_device *lane,
+ enum coef_field field);
+
+void lt_move_lp_back(struct lane_device *lane);
+
+void lt_set_error(struct lane_device *lane, bool err);
+
+/* Backplane Driver Interface for EQ Algorithms:
+ * Used by equalization algorithms to interact
+ * with backplane driver during equalization
+ */
+
+/* equalization algorithm registration */
+int backplane_eq_register(const char *key,
+ const struct equalization_algorithm *eq_info);
+void backplane_eq_unregister(const char *key);
+
+bool backplane_is_cdr_lock(struct lane_device *lane, bool retry);
+
+void bpdev_err(struct phy_device *phydev, char *fmt, ...);
+
+void bpdev_warn(struct phy_device *phydev, char *fmt, ...);
+
+void bpdev_info(struct phy_device *phydev, char *fmt, ...);
+
+void bpdev_dbg(struct phy_device *phydev, char *fmt, ...);
+
+#endif /* __EQUALIZATION_H */
diff --git a/drivers/net/phy/backplane/link_training.c b/drivers/net/phy/backplane/link_training.c
new file mode 100644
index 0000000..87b376c
--- /dev/null
+++ b/drivers/net/phy/backplane/link_training.c
@@ -0,0 +1,1529 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/* Link Training (IEEE802.3ap/ba)
+ * Ethernet Operation over Electrical Backplanes
+ *
+ * Copyright 2019-2020 NXP
+ */
+
+#include <linux/mdio.h>
+#include <linux/timer.h>
+#include <linux/delay.h>
+
+#include "link_training.h"
+
+/* KR LP/LD Coefficients */
+#define PRESET_MASK 0x2000
+#define INIT_MASK 0x1000
+#define COP1_MASK 0x30
+#define COP1_SHIFT 4
+#define COZ0_MASK 0xc
+#define COZ0_SHIFT 2
+#define COM1_MASK 0x3
+#define COM1_SHIFT 0
+#define ALL_COEF_MASK (COP1_MASK | COZ0_MASK | COM1_MASK)
+#define LD_ALL_MASK (PRESET_MASK | INIT_MASK | ALL_COEF_MASK)
+
+/* KR LP Status Report */
+#define LP_STATUS_ALL_COEF_UPDATED 0x15
+
+/* KR LP/LD Status Report:
+ * RX_READY_MASK - Receiver Ready
+ * 0b - The LP/LD receiver is requesting that training continue
+ * 1b - The LP/LD receiver has determined that training is complete
+ * and is prepared to receive data.
+ */
+#define RX_READY_MASK 0x8000
+
+/* Increment/Decrement Requests */
+#define HOLD 0
+#define INCREMENT 1
+#define DECREMENT 2
+#define RESERVED 3
+
+/* Increment/Decrement Steps */
+#define STEP_INCREMENT_P1 -1
+#define STEP_INCREMENT_Z0 1
+#define STEP_INCREMENT_M1 -1
+
+/* KR PMD Control defines */
+#define TRAIN_EN 0x3
+#define TRAIN_DISABLE 0x1
+#define PMD_RESET 0x1
+
+/* KR PMD Status defines */
+#define PMD_STATUS_TRAIN_FAIL 0x8
+#define PMD_STATUS_SUP_STAT 0x4
+#define PMD_STATUS_FRAME_LOCK 0x2
+#define PMD_STATUS_RX_STAT 0x1
+
+/* KR PMD control register (Register 1.150) */
+#define KR_PMD_BASE_OFFSET 150
+
+/* Link training KR PMD registers offsets (relative to base) */
+#define OFFSET_KR_PMD_CTRL 0x0
+#define OFFSET_KR_PMD_STATUS 0x1
+#define OFFSET_KR_LP_CU 0x2
+#define OFFSET_KR_LP_STATUS 0x3
+#define OFFSET_KR_LD_CU 0x4
+#define OFFSET_KR_LD_STATUS 0x5
+
+/* Timeouts */
+#define TIMEOUT_MOVE_BACK_PREV 6
+#define TIMEOUT_REPEAT_REQUEST 10
+
+/* Training for Remote Tx */
+
+static u32 get_mask_for_req(enum req_type req)
+{
+ u32 cmd = HOLD;
+
+ switch (req) {
+ case REQ_HOLD:
+ cmd = HOLD;
+ break;
+ case REQ_INC:
+ cmd = INCREMENT;
+ break;
+ case REQ_DEC:
+ cmd = DECREMENT;
+ break;
+ case REQ_INIT:
+ cmd = INIT_MASK;
+ break;
+ case REQ_PRESET:
+ cmd = PRESET_MASK;
+ break;
+ case REQ_INVALID:
+ cmd = RESERVED;
+ break;
+ default:
+ cmd = HOLD;
+ break;
+ }
+ return cmd;
+}
+
+static enum req_type get_req_for_mask(u32 cmd)
+{
+ enum req_type req = REQ_HOLD;
+
+ switch (cmd) {
+ case HOLD:
+ req = REQ_HOLD;
+ break;
+ case INCREMENT:
+ req = REQ_INC;
+ break;
+ case DECREMENT:
+ req = REQ_DEC;
+ break;
+ case INIT_MASK:
+ req = REQ_INIT;
+ break;
+ case PRESET_MASK:
+ req = REQ_PRESET;
+ break;
+ case RESERVED:
+ req = REQ_INVALID;
+ break;
+ default:
+ req = REQ_HOLD;
+ break;
+ }
+ return req;
+}
+
+/* ld_coef_status
+ * 72.6.10.2.5 Coefficient update process
+ * Once the updated, maximum, or minimum state is reported it continues
+ * to be reported until a hold request is received,
+ * after which the status reverts to not_updated.
+ */
+static void ld_coef_status(struct lane_device *lane)
+{
+ backplane_write_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.ld_status,
+ lane->krln.ld_status);
+}
+
+/* ld_coef_update
+ * LD sends to LP the specified request for coefficients update
+ */
+static void ld_coef_update(struct lane_device *lane)
+{
+ backplane_write_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.ld_cu,
+ lane->krln.ld_update);
+}
+
+/* get_lp_lcs
+ * get LP lcs (last change status)
+ * returns the last LP change (non-zero) status:
+ * meaning the last LP status resulted from a change request
+ * 72.6.10.2.5 Coefficient update process
+ * Once the updated, maximum, or minimum state is reported it continues
+ * to be reported until a hold request is received,
+ * after which the status reverts to not_updated.
+ */
+static u32 get_lp_lcs(struct lane_device *lane)
+{
+ return lane->krln.lp_last_change_status;
+}
+
+static bool is_all_status(u32 status, enum coef_status cs)
+{
+ return ((status & ALL_COEF_MASK) ==
+ (cs << COP1_SHIFT | cs << COZ0_SHIFT | cs << COM1_SHIFT));
+}
+
+/* Training for Local Tx */
+
+static void initialize(struct lane_device *lane)
+{
+ backplane_default_kr_lane(lane);
+
+ lane->krln.ld_status &= ~ALL_COEF_MASK;
+ lane->krln.ld_status |= COEF_UPDATED << COP1_SHIFT |
+ COEF_UPDATED << COZ0_SHIFT |
+ COEF_UPDATED << COM1_SHIFT;
+
+ ld_coef_status(lane);
+}
+
+/* preset
+ * Preset as defined by: IEEE 802.3, sub-clause 72.6.10.2.3.1
+ * Setup all coefficients to MAX values from IEEE802.3 perspective
+ */
+static void preset(struct lane_device *lane)
+{
+ backplane_set_all_taps_to_max(lane);
+
+ backplane_tune_kr_lane(lane, true);
+
+ lane->krln.ld_status &= ~ALL_COEF_MASK;
+ lane->krln.ld_status |= COEF_MAX << COP1_SHIFT |
+ COEF_MAX << COZ0_SHIFT |
+ COEF_MAX << COM1_SHIFT;
+
+ ld_coef_status(lane);
+}
+
+static bool is_rx_ready(u32 status)
+{
+ return ((status & RX_READY_MASK) != 0);
+}
+
+/* is_ld_valid
+ * LD coefficient values have hardware restrictions
+ * Check if all ld coefficients are in range
+ */
+static int is_ld_valid(struct lane_device *lane, u32 *ld_coef)
+{
+ struct backplane_kr *bpkr = &lane->bpdev->bpkr;
+ u32 mainq = ld_coef[C_Z0];
+ u32 postq = ld_coef[C_P1];
+ u32 preq = ld_coef[C_M1];
+
+ /* Basic HW restrictions: */
+
+ /* 1. tx_preq <= MIN_C(-1) */
+ if (preq > bpkr->min_kr.preq)
+ return -ERANGE;
+ /* 2. tx_ratio_post1q <= MIN_C(+1) */
+ if (postq > bpkr->min_kr.postq)
+ return -ERANGE;
+ /* 3. MIN_C(0) <= tx_mainq <= MAX_C(0) */
+ if (mainq < bpkr->min_kr.mainq)
+ return -ERANGE;
+ if (mainq > bpkr->max_kr.mainq)
+ return -ERANGE;
+ /* 4. tx_ratio_post1q >= tx_preq */
+ if (postq < preq)
+ return -ERANGE;
+
+ /* Additional HW restrictions:
+ * LT custom HW validation: Device specific HW restrictions
+ */
+ if (lane->bpdev->drv.bp_ops.lt_validation)
+ return lane->bpdev->drv.bp_ops.lt_validation(lane, ld_coef);
+
+ return 0;
+}
+
+static bool update_ld_status(struct lane_device *lane, enum coef_field field,
+ enum coef_status cs)
+{
+ u32 ld_cs = cs;
+ u32 mask, val;
+
+ if (cs == COEF_INVALID)
+ return false;
+
+ switch (field) {
+ case C_P1:
+ mask = COP1_MASK;
+ val = ld_cs << COP1_SHIFT;
+ break;
+ case C_Z0:
+ mask = COZ0_MASK;
+ val = ld_cs << COZ0_SHIFT;
+ break;
+ case C_M1:
+ mask = COM1_MASK;
+ val = ld_cs << COM1_SHIFT;
+ break;
+ default:
+ return false;
+ }
+
+ lane->krln.ld_status &= ~mask;
+ lane->krln.ld_status |= val;
+
+ return true;
+}
+
+static enum coef_status inc_dec(struct lane_device *lane,
+ enum coef_field field, int request)
+{
+ u32 ld_coef[C_NO], step[C_NO], ld_limit[C_NO];
+ int err;
+
+ backplane_get_current_taps(lane, ld_coef);
+
+ step[C_M1] = STEP_INCREMENT_M1;
+ step[C_Z0] = STEP_INCREMENT_Z0;
+ step[C_P1] = STEP_INCREMENT_P1;
+
+ /* 72.6.10.2.5 Coefficient update process
+ * Upon execution of a received increment or decrement request,
+ * the status is reported as updated, maximum, or minimum.
+ */
+ switch (request) {
+ case INCREMENT:
+ ld_limit[C_M1] = lane->bpdev->bpkr.max_kr.preq;
+ ld_limit[C_Z0] = lane->bpdev->bpkr.max_kr.mainq;
+ ld_limit[C_P1] = lane->bpdev->bpkr.max_kr.postq;
+ if (ld_coef[field] != ld_limit[field])
+ ld_coef[field] += step[field];
+ else
+ return COEF_MAX;
+ break;
+ case DECREMENT:
+ ld_limit[C_M1] = lane->bpdev->bpkr.min_kr.preq;
+ ld_limit[C_Z0] = lane->bpdev->bpkr.min_kr.mainq;
+ ld_limit[C_P1] = lane->bpdev->bpkr.min_kr.postq;
+ if (ld_coef[field] != ld_limit[field])
+ ld_coef[field] -= step[field];
+ else
+ return COEF_MIN;
+ break;
+ default:
+ break;
+ }
+
+ err = is_ld_valid(lane, ld_coef);
+ if (!err) {
+ /* accept new ld coefficients */
+ backplane_set_current_taps(lane, ld_coef);
+ backplane_tune_kr_lane(lane, false);
+ } else {
+ if (request == DECREMENT)
+ return COEF_MIN;
+ if (request == INCREMENT)
+ return COEF_MAX;
+ }
+
+ /* UPDATED */
+ return COEF_UPDATED;
+}
+
+static void check_request(struct lane_device *lane, int request)
+{
+ enum coef_status cu = COEF_INVALID;
+ int cop1_req, coz0_req, com1_req;
+ int old_status;
+
+ cop1_req = (request & COP1_MASK) >> COP1_SHIFT;
+ coz0_req = (request & COZ0_MASK) >> COZ0_SHIFT;
+ com1_req = (request & COM1_MASK) >> COM1_SHIFT;
+
+ /* IEEE802.3-2008, 72.6.10.2.5
+ * Ensure we only act on INCREMENT/DECREMENT when we are in NOT UPDATED
+ *
+ * 72.6.10.2.5 Coefficient update process
+ * An increment or decrement request will only be acted upon when
+ * the state of the tap is not_updated.
+ */
+ old_status = lane->krln.ld_status;
+
+ if (cop1_req && !(lane->krln.ld_status & COP1_MASK)) {
+ cu = inc_dec(lane, C_P1, cop1_req);
+ update_ld_status(lane, C_P1, cu);
+ }
+
+ if (coz0_req && !(lane->krln.ld_status & COZ0_MASK)) {
+ cu = inc_dec(lane, C_Z0, coz0_req);
+ update_ld_status(lane, C_Z0, cu);
+ }
+
+ if (com1_req && !(lane->krln.ld_status & COM1_MASK)) {
+ cu = inc_dec(lane, C_M1, com1_req);
+ update_ld_status(lane, C_M1, cu);
+ }
+
+ if (old_status != lane->krln.ld_status)
+ ld_coef_status(lane);
+}
+
+static void training_complete(struct lane_device *lane)
+{
+ struct training_status *trst = &lane->krln.trst;
+
+ /* update training status */
+ trst->remote_tx_complete = true;
+ trst->remote_tx_running = false;
+
+ /* report LD status */
+ lane->krln.ld_status |= RX_READY_MASK;
+ ld_coef_status(lane);
+
+ /* update PMD status and tell LP we are ready */
+ backplane_write_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.status,
+ PMD_STATUS_RX_STAT);
+}
+
+/* Link Training general API */
+
+/* Setup standard KR LT MMD (MDIO Managed Device) for Clause 45
+ * 45.2.1.76 10GBASE-KR PMD control register (Register 1.150)
+ */
+void lt_mmd_c45(struct backplane_kr *bpkr)
+{
+ lt_mmd_setup(bpkr, MDIO_MMD_PMAPMD, KR_PMD_BASE_OFFSET);
+}
+
+/* Setup KR LT MMD (MDIO Managed Device)
+ * IEEE Std 802.3ap-2007: Table 45.3 PMA/PMD registers
+ */
+void lt_mmd_setup(struct backplane_kr *bpkr, int devad, u32 base)
+{
+ bpkr->ltmmd.devad = devad;
+ bpkr->ltmmd.control = base + OFFSET_KR_PMD_CTRL;
+ bpkr->ltmmd.status = base + OFFSET_KR_PMD_STATUS;
+ bpkr->ltmmd.lp_cu = base + OFFSET_KR_LP_CU;
+ bpkr->ltmmd.lp_status = base + OFFSET_KR_LP_STATUS;
+ bpkr->ltmmd.ld_cu = base + OFFSET_KR_LD_CU;
+ bpkr->ltmmd.ld_status = base + OFFSET_KR_LD_STATUS;
+}
+
+/* lt_is_lp_rx_ready
+ * Reports if LP Receiver is ready
+ * false: The LP receiver is requesting that training continue
+ * true: The LP receiver has determined that training is complete
+ * and is prepared to receive data.
+ */
+bool lt_is_lp_rx_ready(struct lane_device *lane)
+{
+ struct kr_lt_mmd *ltmmd = &lane->bpdev->bpkr.ltmmd;
+
+ /* Read LP Status */
+ lane->krln.lp_status = backplane_read_mmd(lane,
+ ltmmd->devad,
+ ltmmd->lp_status);
+ return is_rx_ready(lane->krln.lp_status);
+}
+
+/* lt_is_ld_rx_ready
+ * Reports if LD Receiver is ready
+ * false: The LD receiver is requesting that training continue
+ * true: The LD receiver has determined that training is complete
+ * and is prepared to receive data.
+ */
+bool lt_is_ld_rx_ready(struct lane_device *lane)
+{
+ return is_rx_ready(lane->krln.ld_status);
+}
+
+void lt_start(struct lane_device *lane)
+{
+ backplane_write_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.control,
+ TRAIN_EN);
+}
+
+void lt_stop(struct lane_device *lane)
+{
+ backplane_write_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.control,
+ TRAIN_DISABLE);
+}
+
+void lt_reset(struct lane_device *lane)
+{
+ backplane_write_mmd(lane, lane->bpdev->bpkr.ltmmd.devad, MDIO_CTRL1,
+ PMD_RESET);
+ backplane_write_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.control,
+ TRAIN_DISABLE);
+ backplane_write_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.ld_cu, 0);
+ backplane_write_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.ld_status, 0);
+ backplane_write_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.status, 0);
+ backplane_write_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.lp_cu, 0);
+ backplane_write_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.lp_status, 0);
+}
+
+/* lt_is_rx_trained
+ * IEEE Std 802.3ap-2007: Table 72.3 MDIO/PMD status variable mapping
+ * PMD status variable: rx_trained
+ */
+bool lt_is_rx_trained(struct lane_device *lane)
+{
+ struct phy_device *phydev = lane->phydev;
+ int timeout = 100;
+ int val;
+
+ val = backplane_read_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.status);
+
+ if ((val & PMD_STATUS_RX_STAT) && !(val & PMD_STATUS_TRAIN_FAIL)) {
+ while (timeout--) {
+ if (backplane_is_link_up(phydev))
+ return true;
+
+ usleep_range(100, 500);
+ }
+ }
+ return false;
+}
+
+/* lt_is_training_failure
+ * IEEE Std 802.3ap-2007: Table 72.3 MDIO/PMD status variable mapping
+ * PMD status variable: PMD_fault
+ */
+bool lt_is_training_failure(struct lane_device *lane)
+{
+ struct kr_lt_mmd *ltmmd = &lane->bpdev->bpkr.ltmmd;
+ int lt_state;
+
+ lt_state = backplane_read_mmd(lane, ltmmd->devad, ltmmd->status);
+
+ /* according to spec: 8023ap-2007.pdf
+ * training_failure
+ * Boolean variable that is set to TRUE when the training state machine
+ * has timed out due to expiration of the max_wait_timer while in the
+ * SEND_TRAINING, TRAIN_LOCAL, or
+ * TRAIN_REMOTE states and is set to FALSE otherwise.
+ */
+ if (lt_state & PMD_STATUS_TRAIN_FAIL)
+ return true;
+
+ return false;
+}
+
+/* lt_is_frame_lock
+ * IEEE Std 802.3ap-2007: Table 72.3 MDIO/PMD status variable mapping
+ * PMD status variable: frame_lock
+ */
+bool lt_is_frame_lock(struct lane_device *lane)
+{
+ struct kr_lt_mmd *ltmmd = &lane->bpdev->bpkr.ltmmd;
+ int lt_state;
+
+ lt_state = backplane_read_mmd(lane, ltmmd->devad, ltmmd->status);
+
+ if ((lt_state & PMD_STATUS_SUP_STAT) &&
+ (lt_state & PMD_STATUS_FRAME_LOCK))
+ return true;
+
+ return false;
+}
+
+/* Training for Remote Tx
+ * This is the main routine for Remote Tx training
+ */
+void lt_train_remote_tx(struct lane_device *lane)
+{
+ const struct equalization_algorithm *eq_alg = lane->krln.eq_alg;
+ struct training_status *trst = &lane->krln.trst;
+ u32 prev_req_cp1, prev_req_cz0, prev_req_cm1;
+ u32 status_cp1, status_cz0, status_cm1;
+ u32 prev_req_init, prev_req_preset;
+ u64 lp_resp_time;
+
+ /* Check stop condition for Remote Tx training */
+ if (trst->remote_tx_complete)
+ return;
+
+ /* Check if equalization algorithm is installed */
+ if (!eq_alg)
+ return;
+
+ /* Check that all required callback operations are installed */
+ if (!eq_alg->ops.collect_statistics ||
+ !eq_alg->ops.is_rx_ok ||
+ !eq_alg->ops.generate_request ||
+ !eq_alg->ops.is_eq_done)
+ return;
+
+ /* Start new Remote Tx training step */
+ trst->remote_tx_running = true;
+
+ /* Store current state as previous state */
+ lane->krln.prev_ld_update = lane->krln.ld_update;
+ if ((lane->krln.prev_ld_update & ALL_COEF_MASK) != HOLD)
+ lane->krln.ld_last_nonhold_update = lane->krln.prev_ld_update;
+
+ prev_req_init = lane->krln.prev_ld_update & INIT_MASK;
+ prev_req_preset = lane->krln.prev_ld_update & PRESET_MASK;
+ prev_req_cp1 = (lane->krln.prev_ld_update & COP1_MASK) >> COP1_SHIFT;
+ prev_req_cz0 = (lane->krln.prev_ld_update & COZ0_MASK) >> COZ0_SHIFT;
+ prev_req_cm1 = (lane->krln.prev_ld_update & COM1_MASK) >> COM1_SHIFT;
+
+ /* Training Done condition */
+ if (eq_alg->ops.is_eq_done(lane->krln.eq_priv))
+ trst->done_training = true;
+
+ /* Check if Training is Done */
+ if (trst->done_training) {
+ training_complete(lane);
+ return;
+ }
+
+ /* Read LP Status */
+ lane->krln.lp_status =
+ backplane_read_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.lp_status);
+
+ if ((lane->krln.lp_status & ALL_COEF_MASK) != 0)
+ lane->krln.lp_last_change_status = lane->krln.lp_status;
+
+ status_cp1 = (lane->krln.lp_status & COP1_MASK) >> COP1_SHIFT;
+ status_cz0 = (lane->krln.lp_status & COZ0_MASK) >> COZ0_SHIFT;
+ status_cm1 = (lane->krln.lp_status & COM1_MASK) >> COM1_SHIFT;
+
+ if (status_cp1 == COEF_UPDATED || status_cp1 == COEF_MIN ||
+ status_cp1 == COEF_MAX)
+ lane->krln.last_lp_update_status[C_P1] = status_cp1;
+ if (status_cz0 == COEF_UPDATED || status_cz0 == COEF_MIN ||
+ status_cz0 == COEF_MAX)
+ lane->krln.last_lp_update_status[C_Z0] = status_cz0;
+ if (status_cm1 == COEF_UPDATED || status_cm1 == COEF_MIN ||
+ status_cm1 == COEF_MAX)
+ lane->krln.last_lp_update_status[C_M1] = status_cm1;
+
+ /* IEEE802.3-2008, 72.6.10.2.3.2
+ * we send initialize to the other side to ensure default settings
+ * for the LP. Naturally, we should do this only once.
+ */
+ if (!trst->sent_init) {
+ /* All status MUST be NOTUPDATED for INIT to be executed
+ * otherwise send HOLD first
+ */
+ if (status_cp1 == COEF_NOTUPDATED &&
+ status_cz0 == COEF_NOTUPDATED &&
+ status_cm1 == COEF_NOTUPDATED) {
+ trst->sent_init = true;
+ lane->krln.ld_update = INIT_MASK;
+ lane->krln.req_ld_update_init_count = 1;
+ lane->krln.init_handshake_time =
+ jiffies_to_msecs(jiffies);
+ } else {
+ /* send HOLD before sending subsequent Init requests
+ * this is not the very first Init sent
+ */
+ lane->krln.ld_update = HOLD;
+ }
+ ld_coef_update(lane);
+ return;
+ }
+ /* continue to sent init request until LP responds to init */
+ if (prev_req_init) {
+ if (lane->krln.lp_status == 0) {
+ /* nothing to do here for now
+ * perhaps the partner board LP has not yet started
+ * so continue to send INIT requests
+ * this will happen in the next condition anyway
+ */
+ }
+ /* 72.6.10.2.3.2 Initialize
+ * The initialize control shall only be initially sent when all
+ * coefficient status fields indicate not_updated,
+ * and will then continue to be sent
+ * until no coefficient status field indicates not_updated.
+ */
+ if (status_cp1 == COEF_NOTUPDATED ||
+ status_cz0 == COEF_NOTUPDATED ||
+ status_cm1 == COEF_NOTUPDATED) {
+ lane->krln.ld_update = INIT_MASK;
+ ld_coef_update(lane);
+ lane->krln.req_ld_update_init_count++;
+ } else {
+ /* IEEE802.3-2008, 72.6.10.2.3.2
+ * We may clear INITIALIZE when no coefficients
+ * show NOT UPDATED.
+ */
+ /* v1: lane->krln.ld_update &= ~INIT_MASK; */
+ /* better send request: HOLD ALL
+ * should be equivalent since only INIT is set now
+ */
+ lane->krln.ld_update = HOLD;
+
+ lp_resp_time = jiffies_to_msecs(jiffies) -
+ lane->krln.init_handshake_time;
+ if (!lane->krln.first_recv_init) {
+ /* Init handshake not done yet,
+ * but will be soon
+ */
+ lane->krln.req_ld_update_init_count = 1;
+ lp_resp_time = 0;
+ }
+ ld_coef_update(lane);
+ }
+ return;
+ }
+
+ /* 72.6.10.2.3.1 Preset
+ * The preset control shall only be initially sent when all coefficient
+ * status fields indicate not_updated,
+ * and will then continue to be sent until the status for all
+ * coefficients indicates updated or maximum
+ */
+ /* IEEE802.3-2008, 72.6.10.2.3.1
+ * We may clear PRESET when all coefficients show UPDATED or MAX.
+ */
+ /* check if previous request was preset */
+ if (prev_req_preset) {
+ if ((status_cp1 == COEF_UPDATED || status_cp1 == COEF_MAX) &&
+ (status_cz0 == COEF_UPDATED || status_cz0 == COEF_MAX) &&
+ (status_cm1 == COEF_UPDATED || status_cm1 == COEF_MAX)) {
+ lane->krln.ld_update &= ~PRESET_MASK;
+ } else {
+ /* All status MUST be NOTUPDATED for INIT to be executed
+ * otherwise send HOLD first
+ */
+ if (status_cp1 == COEF_NOTUPDATED &&
+ status_cz0 == COEF_NOTUPDATED &&
+ status_cm1 == COEF_NOTUPDATED) {
+ lane->krln.ld_update = PRESET_MASK;
+ } else {
+ /* send HOLD before sending subsequent
+ * Preset requests
+ */
+ lane->krln.ld_update = HOLD;
+ }
+ ld_coef_update(lane);
+ return;
+ }
+ }
+
+ /* IEEE802.3-2008, 72.6.10.2.3.3
+ * We only request coefficient updates when no PRESET/INITIALIZE is
+ * pending. We also only request coefficient updates when the
+ * corresponding status is NOT UPDATED and nothing is pending.
+ */
+ if (lane->krln.ld_update & (PRESET_MASK | INIT_MASK))
+ return;
+
+ /* continue to move back to previous request until LP responds to it
+ * Move back to previous C(-1), C(0), C(+1) and HOLD
+ */
+ if (lane->krln.move_back_prev) {
+ /* can exit from here only with: DONE Training */
+ if (lane->krln.move_back_cnt == TIMEOUT_MOVE_BACK_PREV) {
+ trst->done_training = true;
+ training_complete(lane);
+ return;
+ }
+ lane->krln.move_back_cnt++;
+
+ if (status_cp1 == COEF_UPDATED)
+ lane->krln.move_back_lp_status |=
+ (COEF_UPDATED << COP1_SHIFT);
+ if (status_cz0 == COEF_UPDATED)
+ lane->krln.move_back_lp_status |=
+ (COEF_UPDATED << COZ0_SHIFT);
+ if (status_cm1 == COEF_UPDATED)
+ lane->krln.move_back_lp_status |=
+ (COEF_UPDATED << COM1_SHIFT);
+
+ if ((lane->krln.move_back_lp_status & ALL_COEF_MASK) ==
+ LP_STATUS_ALL_COEF_UPDATED) {
+ trst->done_training = true;
+ training_complete(lane);
+ return;
+ }
+
+ /* Move back to previous C(-1), C(0), C(+1) */
+ lane->krln.ld_update = lane->krln.prev_ld_update;
+ ld_coef_update(lane);
+ return;
+ }
+
+ /* 72.6.10.2.5 Coefficient update process
+ * Once the updated, maximum, or minimum state is reported it continues
+ * to be reported until a hold request is received,
+ * after which the status reverts to not_updated.
+ */
+
+ /* IEEE802.3-2008, 72.6.10.2.3.3
+ * We set coefficient requests to HOLD when we get the information
+ * about any updates On clearing our prior response, we also update
+ * our internal status.
+ */
+
+ /* send a Hold if want to send another INC same as previous
+ * and received status: NOTUPDATED
+ * 1. Continue to send previous REQ until receive status UPDATED
+ * 2. Continue to send HOLD until receive status NOTUPDATED
+ */
+
+ /* 3. LP can remain stuck ~42 ms in reset Rx lane: so we should wait
+ * around ~50 ms and only after that issue Timeout error message
+ */
+
+ switch (prev_req_cp1) {
+ case HOLD:
+ /* previous request was: HOLD */
+ if (status_cp1 == COEF_NOTUPDATED) {
+ /* All good here:
+ * continue to check the other coefficient requests
+ * and if all are good then proceed to
+ * generate coefficient tuning requests
+ */
+ } else {
+ /* Continue to send the same request: (2.)
+ * Continue to send HOLD until receive status NOTUPDATED
+ */
+ if (lane->krln.repeat_request_count >=
+ TIMEOUT_REPEAT_REQUEST) {
+ bpdev_err(lane->phydev,
+ "REQ Timeout: Repeating C(+1) HOLD request without LP response timeout !\n");
+ /* Hold Request Timeout:
+ * continue to send HOLD until LP responds
+ * with NOTUPDATED
+ */
+ lane->krln.repeat_request_count = 0;
+ } else {
+ /* Allow LP some time to respond
+ * and repeat request
+ */
+ msleep(20);
+ /* Allow LP more time to respond,
+ * as the last chance, on the last time
+ * before issuing timeout error: (3.)
+ */
+ if (lane->krln.repeat_request_count ==
+ TIMEOUT_REPEAT_REQUEST - 1)
+ msleep(30);
+ lane->krln.repeat_request_count++;
+ }
+ ld_coef_update(lane);
+ return;
+ }
+ break;
+ case INCREMENT:
+ case DECREMENT:
+ /* previous request was: INC/DEC */
+ if (status_cp1 == COEF_NOTUPDATED) {
+ /* Continue to send the same request: (1.)
+ * Continue to send previous REQ
+ * until receive status UPDATED
+ */
+ if (lane->krln.repeat_request_count >=
+ TIMEOUT_REPEAT_REQUEST) {
+ if (prev_req_cp1 == INCREMENT)
+ bpdev_err(lane->phydev,
+ "REQ Timeout: Repeating C(+1) INC request without LP response timeout !\n");
+ else
+ bpdev_err(lane->phydev,
+ "REQ Timeout: Repeating C(+1) DEC request without LP response timeout !\n");
+ /* Request Timeout:
+ * just continue: proceed again to
+ * generate coefficient tuning requests
+ */
+ } else {
+ /* Allow LP some time to respond
+ * and repeat request
+ */
+ msleep(20);
+ /* Allow LP more time to respond,
+ * as the last chance,
+ * on the last time before
+ * issuing timeout error: (3.)
+ */
+ if (lane->krln.repeat_request_count ==
+ TIMEOUT_REPEAT_REQUEST - 1)
+ msleep(30);
+ lane->krln.repeat_request_count++;
+ ld_coef_update(lane);
+ return;
+ }
+ } else {
+ /* All good here:
+ * LP responded to this Request
+ * Sent HOLD for this coefficient
+ * before asking another request
+ * continue to check the other coefficient requests
+ */
+ lane->krln.ld_update &= ~COP1_MASK;
+ }
+ break;
+ default:
+ /* previous request was: RESERVED: do nothing */
+ break;
+ }
+
+ switch (prev_req_cz0) {
+ case HOLD:
+ /* previous request was: HOLD */
+ if (status_cz0 == COEF_NOTUPDATED) {
+ /* All good here:
+ * continue to check the other coefficient requests
+ * and if all are good then proceed to
+ * generate coefficient tuning requests
+ */
+ } else {
+ /* Continue to send the same request: (2.)
+ * Continue to send HOLD until receive status NOTUPDATED
+ */
+ if (lane->krln.repeat_request_count >=
+ TIMEOUT_REPEAT_REQUEST) {
+ bpdev_err(lane->phydev,
+ "REQ Timeout: Repeating C(0) HOLD request without LP response timeout !\n");
+ /* Hold Request Timeout:
+ * continue to send HOLD until LP responds
+ * with NOTUPDATED
+ */
+ lane->krln.repeat_request_count = 0;
+ } else {
+ /* Allow LP some time to respond
+ * and repeat request
+ */
+ msleep(20);
+ /* Allow LP more time to respond,
+ * as the last chance,
+ * on the last time before issuing
+ * timeout error: (3.)
+ */
+ if (lane->krln.repeat_request_count ==
+ TIMEOUT_REPEAT_REQUEST - 1)
+ msleep(30);
+ lane->krln.repeat_request_count++;
+ }
+ ld_coef_update(lane);
+ return;
+ }
+ break;
+ case INCREMENT:
+ case DECREMENT:
+ /* previous request was: INC/DEC */
+ if (status_cz0 == COEF_NOTUPDATED) {
+ /* Continue to send the same request: (1.)
+ * Continue to send previous REQ until receive
+ * status UPDATED
+ */
+ if (lane->krln.repeat_request_count >=
+ TIMEOUT_REPEAT_REQUEST) {
+ if (prev_req_cz0 == INCREMENT)
+ bpdev_err(lane->phydev,
+ "REQ Timeout: Repeating C(0) INC request without LP response timeout !\n");
+ else
+ bpdev_err(lane->phydev,
+ "REQ Timeout: Repeating C(0) DEC request without LP response timeout !\n");
+ /* Request Timeout:
+ * just continue: proceed again to
+ * generate coefficient tuning requests
+ */
+ } else {
+ /* Allow LP some time to respond
+ * and repeat request
+ */
+ msleep(20);
+ /* Allow LP more time to respond, as the last
+ * chance, on the last time before issuing
+ * timeout error: (3.)
+ */
+ if (lane->krln.repeat_request_count ==
+ TIMEOUT_REPEAT_REQUEST - 1)
+ msleep(30);
+ lane->krln.repeat_request_count++;
+ ld_coef_update(lane);
+ return;
+ }
+ } else {
+ /* All good here:
+ * LP responded to this Request
+ * Sent HOLD for this coefficient
+ * before asking another request
+ * continue to check the other coefficient requests
+ */
+ lane->krln.ld_update &= ~COZ0_MASK;
+ }
+ break;
+ default:
+ /* previous request was: RESERVED: do nothing */
+ break;
+ }
+
+ switch (prev_req_cm1) {
+ case HOLD:
+ /* previous request was: HOLD */
+ if (status_cm1 == COEF_NOTUPDATED) {
+ /* All good here:
+ * continue to check the other coefficient requests
+ * and if all are good then proceed to
+ * generate coefficient tuning requests
+ */
+ } else {
+ /* Continue to send the same request: (2.)
+ * Continue to send HOLD until receive status
+ * NOTUPDATED
+ */
+ if (lane->krln.repeat_request_count >=
+ TIMEOUT_REPEAT_REQUEST) {
+ bpdev_err(lane->phydev,
+ "REQ Timeout: Repeating C(-1) HOLD request without LP response timeout !\n");
+ /* Hold Request Timeout:
+ * continue to send HOLD until
+ * LP responds with NOTUPDATED
+ */
+ lane->krln.repeat_request_count = 0;
+ } else {
+ /* Allow LP some time to respond
+ * and repeat request
+ */
+ msleep(20);
+ /* Allow LP more time to respond,
+ * as the last chance,
+ * on the last time
+ * before issuing timeout error: (3.)
+ */
+ if (lane->krln.repeat_request_count ==
+ TIMEOUT_REPEAT_REQUEST - 1)
+ msleep(30);
+ lane->krln.repeat_request_count++;
+ }
+ ld_coef_update(lane);
+ return;
+ }
+ break;
+ case INCREMENT:
+ case DECREMENT:
+ /* previous request was: INC/DEC */
+ if (status_cm1 == COEF_NOTUPDATED) {
+ /* Continue to send the same request: (1.)
+ * Continue to send previous REQ until receive status
+ * UPDATED
+ */
+ if (lane->krln.repeat_request_count >=
+ TIMEOUT_REPEAT_REQUEST) {
+ if (prev_req_cm1 == INCREMENT)
+ bpdev_err(lane->phydev,
+ "REQ Timeout: Repeating C(-1) INC request without LP response timeout !\n");
+ else
+ bpdev_err(lane->phydev,
+ "REQ Timeout: Repeating C(-1) DEC request without LP response timeout !\n");
+ /* Request Timeout:
+ * just continue: proceed again to
+ * generate coefficient tuning requests
+ */
+ } else {
+ /* Allow LP some time to respond and repeat
+ * request
+ */
+ msleep(20);
+ /* Allow LP more time to respond, as the last
+ * chance, on the last time before issuing
+ * timeout error: (3.)
+ */
+ if (lane->krln.repeat_request_count ==
+ TIMEOUT_REPEAT_REQUEST - 1)
+ msleep(30);
+ lane->krln.repeat_request_count++;
+ ld_coef_update(lane);
+ return;
+ }
+ } else {
+ /* All good here:
+ * LP responded to this Request
+ * Sent HOLD for this coefficient
+ * before asking another request
+ * continue to check the other coefficient requests
+ */
+ lane->krln.ld_update &= ~COM1_MASK;
+ }
+ break;
+ default:
+ /* previous request was: RESERVED: do nothing */
+ break;
+ }
+
+ /* Reset repeat request counter:
+ * must be after all prev_req verifications above
+ */
+ lane->krln.repeat_request_count = 0;
+
+ if (lane->krln.prev_ld_update != lane->krln.ld_update) {
+ ld_coef_update(lane);
+ /* Redo these status checks and updates until we have no more
+ * changes, to speed up the overall process.
+ */
+ return;
+ }
+
+ /* Do nothing if we have pending request. */
+ if (prev_req_cp1 || prev_req_cz0 || prev_req_cm1)
+ return;
+ else if (lane->krln.lp_status & ALL_COEF_MASK)
+ /* No pending request but LP status was not reverted to
+ * not updated.
+ */
+ return;
+
+ /* Initialize status for the current step */
+ lane->krln.lt_error = false;
+
+ /* if CDR_LOCK = 0: Statistics are invalid */
+ if (!backplane_is_cdr_lock(lane, true)) {
+ if (eq_alg->ops.process_bad_state)
+ eq_alg->ops.process_bad_state(lane->krln.eq_priv);
+ return;
+ }
+
+ /* collect bit edge statistics */
+ if (!eq_alg->ops.collect_statistics(lane->krln.eq_priv))
+ return;
+
+ /* if CDR_LOCK = 0: Statistics are invalid */
+ if (!backplane_is_cdr_lock(lane, true)) {
+ if (eq_alg->ops.process_bad_state)
+ eq_alg->ops.process_bad_state(lane->krln.eq_priv);
+ return;
+ }
+
+ /* Check Rx */
+ if (!eq_alg->ops.is_rx_ok(lane->krln.eq_priv)) {
+ if (eq_alg->ops.process_bad_state)
+ eq_alg->ops.process_bad_state(lane->krln.eq_priv);
+ return;
+ }
+ eq_alg->ops.generate_request(lane->krln.eq_priv);
+
+ /* All C are in Hold and both Bins are stopped:
+ * So the Training is done
+ */
+ if (eq_alg->ops.is_eq_done(lane->krln.eq_priv)) {
+ trst->done_training = true;
+ training_complete(lane);
+ }
+}
+
+/* Training for Local Tx
+ * Initialize LD (Local Device)
+ */
+void lt_init_ld(struct lane_device *lane)
+{
+ /* report initial ld status to lp */
+ lane->krln.ld_status = 0;
+ ld_coef_status(lane);
+}
+
+/* Training for Local Tx
+ * This is the main routine for Local Tx training
+ */
+void lt_train_local_tx(struct lane_device *lane)
+{
+ struct training_status *trst = &lane->krln.trst;
+ int request, old_ld_status;
+
+ /* Check stop condition for Local Tx training */
+ trst->lp_rx_ready = lt_is_lp_rx_ready(lane);
+ if (trst->lp_rx_ready) {
+ /* LP receiver is ready
+ * As soon as the LP shows ready,
+ * no need to do any more updates.
+ */
+ lane->krln.ld_status &= ~ALL_COEF_MASK;
+ ld_coef_status(lane);
+
+ trst->local_tx_running = false;
+ return;
+ }
+
+ /* Start new Local Tx training step */
+ trst->local_tx_running = true;
+
+ /* get request from LP */
+ request = backplane_read_mmd(lane, lane->bpdev->bpkr.ltmmd.devad,
+ lane->bpdev->bpkr.ltmmd.lp_cu) &
+ LD_ALL_MASK;
+
+ old_ld_status = lane->krln.ld_status;
+
+ /* IEEE802.3-2008, 72.6.10.2.5
+ * Ensure we always go to NOT UDPATED for status reporting in
+ * response to HOLD requests.
+ * IEEE802.3-2008, 72.6.10.2.3.1/2
+ * ... but only if PRESET/INITIALIZE are not active to ensure
+ * we keep status until they are released.
+ *
+ * 72.6.10.2.5 Coefficient update process
+ * Once the updated, maximum, or minimum state is reported it continues
+ * to be reported until a hold request is received,
+ * after which the status reverts to not_updated.
+ */
+ if (!(request & (PRESET_MASK | INIT_MASK))) {
+ /* Reset status on HOLD request */
+ if (!(request & COP1_MASK))
+ lane->krln.ld_status &= ~COP1_MASK;
+
+ if (!(request & COZ0_MASK))
+ lane->krln.ld_status &= ~COZ0_MASK;
+
+ if (!(request & COM1_MASK))
+ lane->krln.ld_status &= ~COM1_MASK;
+
+ ld_coef_status(lane);
+ }
+
+ /* IEEE802.3-2008, 72.6.10.2.3.1/2
+ * only act on PRESET/INITIALIZE if all status is NOT UPDATED.
+ */
+ if (request & (PRESET_MASK | INIT_MASK)) {
+ if (!(lane->krln.ld_status & ALL_COEF_MASK)) {
+ if (request & PRESET_MASK)
+ preset(lane);
+
+ if (request & INIT_MASK) {
+ if (!lane->krln.first_recv_init) {
+ lane->krln.first_recv_init = true;
+ /* Init requests must be counted
+ * from initial handshake
+ */
+ lane->krln.req_ld_update_init_count = 1;
+ lane->krln.init_handshake_time =
+ jiffies_to_msecs(jiffies);
+ }
+ initialize(lane);
+ }
+ } else {
+ /* Inform the partner about current ld status
+ * which should be: ALL UPDATED for INIT and
+ * ALL MAX for PRESET
+ */
+ ld_coef_status(lane);
+ }
+ }
+
+ /* check if LP Coefficient are not in HOLD */
+ if (request & ALL_COEF_MASK)
+ check_request(lane, request & ALL_COEF_MASK);
+
+ /* Make sure the partner is always informed about the current ld status
+ * this will ensure avoidance of several training issues and errors:
+ * 'link_training_failed'
+ * 'Repeating request without LP response'
+ */
+ ld_coef_status(lane);
+}
+
+/* Training for Remote Tx API */
+
+/* lt_lp_update
+ *
+ * Sends to LP the specified request for coefficients update
+ *
+ * lane: desired lane for which to send lp update
+ * update: desired update request to be sent to LP
+ *
+ * Returns: None
+ */
+void lt_lp_update(struct lane_device *lane, u32 update)
+{
+ lane->krln.ld_update = update;
+ ld_coef_update(lane);
+}
+EXPORT_SYMBOL(lt_lp_update);
+
+/* lt_encode_request
+ *
+ * Encodes a request in the update word
+ * and adds it to other bit requests already existent in the update word
+ *
+ * base_update: base update word used to add a new desired request
+ * req: desired request type to be encoded
+ * field: the field for which the request must be encoded
+ *
+ * Returns: the encoded update word
+ */
+u32 lt_encode_request(u32 base_update, enum req_type req,
+ enum coef_field field)
+{
+ u32 new_cmd = base_update;
+ u32 cmd;
+
+ if (req >= REQ_INIT)
+ return RESERVED;
+
+ cmd = get_mask_for_req(req);
+
+ switch (field) {
+ case C_P1:
+ new_cmd |= (cmd << COP1_SHIFT);
+ break;
+ case C_Z0:
+ new_cmd |= (cmd << COZ0_SHIFT);
+ break;
+ case C_M1:
+ new_cmd |= (cmd << COM1_SHIFT);
+ break;
+ default:
+ return RESERVED;
+ }
+ return new_cmd;
+}
+EXPORT_SYMBOL(lt_encode_request);
+
+/* lt_encode_startup_request
+ *
+ * Encodes a startup request in the update word
+ *
+ * req: desired startup request type to be encoded
+ *
+ * Returns: the encoded update word
+ */
+u32 lt_encode_startup_request(enum req_type req)
+{
+ if (req == REQ_HOLD || req == REQ_INIT || req == REQ_PRESET)
+ return get_mask_for_req(req);
+
+ return RESERVED;
+}
+EXPORT_SYMBOL(lt_encode_startup_request);
+
+/* lt_decode_coef_update
+ *
+ * Decodes a request update for the specified field
+ *
+ * update: update word to be decoded
+ * field: desired field for which to decode the update
+ *
+ * Returns: the decoded request type
+ */
+enum req_type lt_decode_coef_update(u32 update, enum coef_field field)
+{
+ u32 cmd = HOLD;
+
+ switch (field) {
+ case C_P1:
+ cmd = (update & COP1_MASK) >> COP1_SHIFT;
+ break;
+ case C_Z0:
+ cmd = (update & COZ0_MASK) >> COZ0_SHIFT;
+ break;
+ case C_M1:
+ cmd = (update & COM1_MASK) >> COM1_SHIFT;
+ break;
+ default:
+ return REQ_INVALID;
+ }
+
+ return get_req_for_mask(cmd);
+}
+EXPORT_SYMBOL(lt_decode_coef_update);
+
+/* lt_is_update_of_type
+ *
+ * Checks if a request update is according to the specified type
+ * by checking the specific request bit in update word
+ *
+ * update: desired update word to be verified
+ * type: desired type to check against
+ *
+ * Returns: true if update is according to asked type or false otherwise
+ */
+bool lt_is_update_of_type(u32 update, enum req_type type)
+{
+ u32 mask = HOLD;
+
+ switch (type) {
+ case REQ_HOLD:
+ return (update == HOLD);
+ case REQ_INC:
+ mask |= (INCREMENT << COP1_SHIFT);
+ mask |= (INCREMENT << COZ0_SHIFT);
+ mask |= (INCREMENT << COM1_SHIFT);
+ return ((update & mask) != 0);
+ case REQ_DEC:
+ mask |= (DECREMENT << COP1_SHIFT);
+ mask |= (DECREMENT << COZ0_SHIFT);
+ mask |= (DECREMENT << COM1_SHIFT);
+ return ((update & mask) != 0);
+ case REQ_INIT:
+ return ((update & INIT_MASK) != 0);
+ case REQ_PRESET:
+ return ((update & PRESET_MASK) != 0);
+ default:
+ return false;
+ }
+ return false;
+}
+EXPORT_SYMBOL(lt_is_update_of_type);
+
+/* lt_is_lp_at_startup
+ *
+ * Checks if LP status is still at startup status: INIT or PRESET
+ *
+ * lane: desired lane to be verified
+ * req: request type to check startup status
+ * it makes sense only for INIT or PRESET requests
+ *
+ * Returns: true if LP status is still at startup status or false otherwise
+ */
+bool lt_is_lp_at_startup(struct lane_device *lane, enum req_type type)
+{
+ u32 lp_lcs = get_lp_lcs(lane);
+ u32 lp_st = lane->krln.lp_status;
+ bool lp_startup;
+
+ /* LP status still at Init/Preset:
+ * IF now LP status is Init/Preset
+ * OR (now LP status is NOTUPDATED
+ * AND the last nonzero LP status was Init/Preset)
+ */
+ switch (type) {
+ case REQ_INIT:
+ if (is_all_status(lp_st, COEF_UPDATED))
+ lp_startup = true;
+ else
+ lp_startup = is_all_status(lp_st, COEF_NOTUPDATED) &&
+ is_all_status(lp_lcs, COEF_UPDATED);
+ break;
+ case REQ_PRESET:
+ /* LP status still at Preset
+ * if now LP status is Preset
+ * OR now LP status is NOTUPDATED
+ * AND the last nonzero LP status was Preset
+ */
+ if (is_all_status(lp_st, COEF_MAX) ||
+ is_all_status(lp_st, COEF_UPDATED))
+ lp_startup = true;
+ else
+ lp_startup = is_all_status(lp_st, COEF_NOTUPDATED) &&
+ (is_all_status(lp_lcs, COEF_MAX) ||
+ is_all_status(lp_lcs, COEF_UPDATED));
+ break;
+ default:
+ return false;
+ }
+
+ return lp_startup;
+}
+EXPORT_SYMBOL(lt_is_lp_at_startup);
+
+/* lt_get_lp_coef_status
+ *
+ * Determines the last LP coefficient status
+ * according to IEEE802.3ap-2007:
+ * 72.6.10.2.5 Coefficient update process
+ *
+ * lane: desired lane to be verified
+ * field: coefficient field to be verified
+ *
+ * Returns: the last LP coefficient status
+ */
+enum coef_status lt_get_lp_coef_status(struct lane_device *lane,
+ enum coef_field field)
+{
+ return lane->krln.last_lp_update_status[field];
+}
+EXPORT_SYMBOL(lt_get_lp_coef_status);
+
+/* lt_set_error
+ *
+ * Sets or resets the LT (Link Training) Error flag
+ * This is used to signal to the generic kr training step procedure
+ * that an LT error state has occurred
+ * and link training cannot be successfully finished
+ *
+ * lane: desired lane to set lt error
+ * err: boolean value that specifies if set or reset the error flag
+ *
+ * Returns: None
+ */
+void lt_set_error(struct lane_device *lane, bool err)
+{
+ lane->krln.lt_error = err;
+}
+EXPORT_SYMBOL(lt_set_error);
+
+/* lt_move_lp_back
+ * Request LP to move back to previous coefficients setup and HOLD
+ * The procedure for sending this request is based on reverting the
+ * latest change request (non-hold update) for all coefficients
+ * This procedure should be used to exit from bad states like not CDR_Lock
+ *
+ * lane: desired lane for which to send lp update
+ *
+ * Returns: None
+ */
+void lt_move_lp_back(struct lane_device *lane)
+{
+ u32 prev_req_cp1 = (lane->krln.ld_last_nonhold_update & COP1_MASK) >>
+ COP1_SHIFT;
+ u32 prev_req_cz0 = (lane->krln.ld_last_nonhold_update & COZ0_MASK) >>
+ COZ0_SHIFT;
+ u32 prev_req_cm1 = (lane->krln.ld_last_nonhold_update & COM1_MASK) >>
+ COM1_SHIFT;
+ u32 temp;
+
+ /* Move back to previous C(-1), C(0), C(+1) and HOLD */
+ temp = HOLD;
+ switch (prev_req_cp1) {
+ case INCREMENT:
+ temp |= DECREMENT << COP1_SHIFT;
+ break;
+ case DECREMENT:
+ temp |= INCREMENT << COP1_SHIFT;
+ break;
+ }
+ switch (prev_req_cz0) {
+ case INCREMENT:
+ temp |= DECREMENT << COZ0_SHIFT;
+ break;
+ case DECREMENT:
+ temp |= INCREMENT << COZ0_SHIFT;
+ break;
+ }
+ switch (prev_req_cm1) {
+ case INCREMENT:
+ temp |= DECREMENT << COM1_SHIFT;
+ break;
+ case DECREMENT:
+ temp |= INCREMENT << COM1_SHIFT;
+ break;
+ }
+
+ lane->krln.ld_update = temp;
+ ld_coef_update(lane);
+
+ /* start the procedure for sending request to move LP back
+ * to previous setup until LP responds to it
+ */
+ lane->krln.move_back_prev = true;
+ lane->krln.move_back_cnt = 0;
+ lane->krln.move_back_lp_status = 0;
+ if (prev_req_cp1 == HOLD)
+ lane->krln.move_back_lp_status |= (COEF_UPDATED << COP1_SHIFT);
+ if (prev_req_cz0 == HOLD)
+ lane->krln.move_back_lp_status |= (COEF_UPDATED << COZ0_SHIFT);
+ if (prev_req_cm1 == HOLD)
+ lane->krln.move_back_lp_status |= (COEF_UPDATED << COM1_SHIFT);
+}
+EXPORT_SYMBOL(lt_move_lp_back);
diff --git a/drivers/net/phy/backplane/link_training.h b/drivers/net/phy/backplane/link_training.h
new file mode 100644
index 0000000..fae5f35
--- /dev/null
+++ b/drivers/net/phy/backplane/link_training.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) */
+/* Link Training (IEEE802.3ap/ba)
+ *
+ * Copyright 2019-2020 NXP
+ */
+
+#ifndef __LINK_TRAINING_H
+#define __LINK_TRAINING_H
+
+#include "backplane.h"
+
+/* Link Training interface with backplane driver */
+
+void lt_start(struct lane_device *lane);
+void lt_stop(struct lane_device *lane);
+void lt_reset(struct lane_device *lane);
+void lt_init_ld(struct lane_device *lane);
+
+void lt_mmd_c45(struct backplane_kr *bpkr);
+void lt_mmd_setup(struct backplane_kr *bpkr, int devad, u32 base);
+
+bool lt_is_rx_trained(struct lane_device *lane);
+bool lt_is_training_failure(struct lane_device *lane);
+bool lt_is_frame_lock(struct lane_device *lane);
+
+bool lt_is_lp_rx_ready(struct lane_device *lane);
+bool lt_is_ld_rx_ready(struct lane_device *lane);
+
+void lt_train_remote_tx(struct lane_device *lane);
+void lt_train_local_tx(struct lane_device *lane);
+
+#endif /* __LINK_TRAINING_H */
--
1.9.1

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