[PATCH net-next v3 3/4] enetc: Add ENETC PF level external MDIO support

From: Claudiu Manoil
Date: Fri Feb 22 2019 - 10:04:34 EST

Each ENETC PF has its own MDIO interface, the corresponding
MDIO registers are mapped in the ENETC's Port register block.
The current patch adds a driver for these PF level MDIO buses,
so that each PF can manage directly its own external link.

Signed-off-by: Alex Marginean <alexandru.marginean@xxxxxxx>
Signed-off-by: Claudiu Manoil <claudiu.manoil@xxxxxxx>
---
v2 - used readx_poll_timeout()
- added mdio node child to the port node
- added code comments, removed redundant err messages,
minor code cleanup
v3 - replaced dev_err w/ dev_dbg for read() issues

drivers/net/ethernet/freescale/enetc/Makefile | 3 +-
drivers/net/ethernet/freescale/enetc/enetc_mdio.c | 199 ++++++++++++++++++++++
drivers/net/ethernet/freescale/enetc/enetc_pf.c | 12 ++
drivers/net/ethernet/freescale/enetc/enetc_pf.h | 6 +
4 files changed, 219 insertions(+), 1 deletion(-)
create mode 100644 drivers/net/ethernet/freescale/enetc/enetc_mdio.c

diff --git a/drivers/net/ethernet/freescale/enetc/Makefile b/drivers/net/ethernet/freescale/enetc/Makefile
index 6976602..7139e41 100644
--- a/drivers/net/ethernet/freescale/enetc/Makefile
+++ b/drivers/net/ethernet/freescale/enetc/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_FSL_ENETC) += fsl-enetc.o
-fsl-enetc-$(CONFIG_FSL_ENETC) += enetc.o enetc_cbdr.o enetc_ethtool.o
+fsl-enetc-$(CONFIG_FSL_ENETC) += enetc.o enetc_cbdr.o enetc_ethtool.o \
+ enetc_mdio.o
fsl-enetc-$(CONFIG_PCI_IOV) += enetc_msg.o
fsl-enetc-objs := enetc_pf.o $(fsl-enetc-y)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_mdio.c b/drivers/net/ethernet/freescale/enetc/enetc_mdio.c
new file mode 100644
index 0000000..77b9cd1
--- /dev/null
+++ b/drivers/net/ethernet/freescale/enetc/enetc_mdio.c
@@ -0,0 +1,199 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/* Copyright 2019 NXP */
+
+#include <linux/mdio.h>
+#include <linux/of_mdio.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+
+#include "enetc_pf.h"
+
+struct enetc_mdio_regs {
+ u32 mdio_cfg; /* MDIO configuration and status */
+ u32 mdio_ctl; /* MDIO control */
+ u32 mdio_data; /* MDIO data */
+ u32 mdio_addr; /* MDIO address */
+};
+
+#define bus_to_enetc_regs(bus) (struct enetc_mdio_regs __iomem *)((bus)->priv)
+
+#define ENETC_MDIO_REG_OFFSET 0x1c00
+#define ENETC_MDC_DIV 258
+
+#define MDIO_CFG_CLKDIV(x) ((((x) >> 1) & 0xff) << 8)
+#define MDIO_CFG_BSY BIT(0)
+#define MDIO_CFG_RD_ER BIT(1)
+#define MDIO_CFG_ENC45 BIT(6)
+ /* external MDIO only - driven on neg MDC edge */
+#define MDIO_CFG_NEG BIT(23)
+
+#define MDIO_CTL_DEV_ADDR(x) ((x) & 0x1f)
+#define MDIO_CTL_PORT_ADDR(x) (((x) & 0x1f) << 5)
+#define MDIO_CTL_READ BIT(15)
+#define MDIO_DATA(x) ((x) & 0xffff)
+
+#define TIMEOUT 1000
+static int enetc_mdio_wait_complete(struct enetc_mdio_regs __iomem *regs)
+{
+ u32 val;
+
+ return readx_poll_timeout(enetc_rd_reg, &regs->mdio_cfg, val,
+ !(val & MDIO_CFG_BSY), 10, 10 * TIMEOUT);
+}
+
+static int enetc_mdio_write(struct mii_bus *bus, int phy_id, int regnum,
+ u16 value)
+{
+ struct enetc_mdio_regs __iomem *regs = bus_to_enetc_regs(bus);
+ u32 mdio_ctl, mdio_cfg;
+ u16 dev_addr;
+ int ret;
+
+ mdio_cfg = MDIO_CFG_CLKDIV(ENETC_MDC_DIV) | MDIO_CFG_NEG;
+ if (regnum & MII_ADDR_C45) {
+ dev_addr = (regnum >> 16) & 0x1f;
+ mdio_cfg |= MDIO_CFG_ENC45;
+ } else {
+ /* clause 22 (ie 1G) */
+ dev_addr = regnum & 0x1f;
+ mdio_cfg &= ~MDIO_CFG_ENC45;
+ }
+
+ enetc_wr_reg(&regs->mdio_cfg, mdio_cfg);
+
+ ret = enetc_mdio_wait_complete(regs);
+ if (ret)
+ return ret;
+
+ /* set port and dev addr */
+ mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
+ enetc_wr_reg(&regs->mdio_ctl, mdio_ctl);
+
+ /* set the register address */
+ if (regnum & MII_ADDR_C45) {
+ enetc_wr_reg(&regs->mdio_addr, regnum & 0xffff);
+
+ ret = enetc_mdio_wait_complete(regs);
+ if (ret)
+ return ret;
+ }
+
+ /* write the value */
+ enetc_wr_reg(&regs->mdio_data, MDIO_DATA(value));
+
+ ret = enetc_mdio_wait_complete(regs);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int enetc_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
+{
+ struct enetc_mdio_regs __iomem *regs = bus_to_enetc_regs(bus);
+ u32 mdio_ctl, mdio_cfg;
+ u16 dev_addr, value;
+ int ret;
+
+ mdio_cfg = MDIO_CFG_CLKDIV(ENETC_MDC_DIV) | MDIO_CFG_NEG;
+ if (regnum & MII_ADDR_C45) {
+ dev_addr = (regnum >> 16) & 0x1f;
+ mdio_cfg |= MDIO_CFG_ENC45;
+ } else {
+ dev_addr = regnum & 0x1f;
+ mdio_cfg &= ~MDIO_CFG_ENC45;
+ }
+
+ enetc_wr_reg(&regs->mdio_cfg, mdio_cfg);
+
+ ret = enetc_mdio_wait_complete(regs);
+ if (ret)
+ return ret;
+
+ /* set port and device addr */
+ mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
+ enetc_wr_reg(&regs->mdio_ctl, mdio_ctl);
+
+ /* set the register address */
+ if (regnum & MII_ADDR_C45) {
+ enetc_wr_reg(&regs->mdio_addr, regnum & 0xffff);
+
+ ret = enetc_mdio_wait_complete(regs);
+ if (ret)
+ return ret;
+ }
+
+ /* initiate the read */
+ enetc_wr_reg(&regs->mdio_ctl, mdio_ctl | MDIO_CTL_READ);
+
+ ret = enetc_mdio_wait_complete(regs);
+ if (ret)
+ return ret;
+
+ /* return all Fs if nothing was there */
+ if (enetc_rd_reg(&regs->mdio_cfg) & MDIO_CFG_RD_ER) {
+ dev_dbg(&bus->dev,
+ "Error while reading PHY%d reg at %d.%hhu\n",
+ phy_id, dev_addr, regnum);
+ return 0xffff;
+ }
+
+ value = enetc_rd_reg(&regs->mdio_data) & 0xffff;
+
+ return value;
+}
+
+int enetc_mdio_probe(struct enetc_pf *pf)
+{
+ struct device *dev = &pf->si->pdev->dev;
+ struct enetc_mdio_regs __iomem *regs;
+ struct device_node *np;
+ struct mii_bus *bus;
+ int ret;
+
+ bus = mdiobus_alloc_size(sizeof(regs));
+ if (!bus)
+ return -ENOMEM;
+
+ bus->name = "Freescale ENETC MDIO Bus";
+ bus->read = enetc_mdio_read;
+ bus->write = enetc_mdio_write;
+ bus->parent = dev;
+ snprintf(bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
+
+ /* store the enetc mdio base address for this bus */
+ regs = pf->si->hw.port + ENETC_MDIO_REG_OFFSET;
+ bus->priv = regs;
+
+ np = of_get_child_by_name(dev->of_node, "mdio");
+ if (!np) {
+ dev_err(dev, "MDIO node missing\n");
+ ret = -EINVAL;
+ goto err_registration;
+ }
+
+ ret = of_mdiobus_register(bus, np);
+ if (ret) {
+ of_node_put(np);
+ dev_err(dev, "cannot register MDIO bus\n");
+ goto err_registration;
+ }
+
+ of_node_put(np);
+ pf->mdio = bus;
+
+ return 0;
+
+err_registration:
+ mdiobus_free(bus);
+
+ return ret;
+}
+
+void enetc_mdio_remove(struct enetc_pf *pf)
+{
+ if (pf->mdio) {
+ mdiobus_unregister(pf->mdio);
+ mdiobus_free(pf->mdio);
+ }
+}
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.c b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
index 7d28f5e..15876a6 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
@@ -746,6 +746,7 @@ static void enetc_pf_netdev_setup(struct enetc_si *si, struct net_device *ndev,

static int enetc_of_get_phy(struct enetc_ndev_priv *priv)
{
+ struct enetc_pf *pf = enetc_si_priv(priv->si);
struct device_node *np = priv->dev->of_node;
int err;

@@ -770,12 +771,22 @@ static int enetc_of_get_phy(struct enetc_ndev_priv *priv)
priv->phy_node = of_node_get(np);
}

+ if (!of_phy_is_fixed_link(np)) {
+ err = enetc_mdio_probe(pf);
+ if (err) {
+ of_node_put(priv->phy_node);
+ return err;
+ }
+ }
+
priv->if_mode = of_get_phy_mode(np);
if (priv->if_mode < 0) {
dev_err(priv->dev, "missing phy type\n");
of_node_put(priv->phy_node);
if (of_phy_is_fixed_link(np))
of_phy_deregister_fixed_link(np);
+ else
+ enetc_mdio_remove(pf);

return -EINVAL;
}
@@ -898,6 +909,7 @@ static void enetc_pf_remove(struct pci_dev *pdev)

unregister_netdev(si->ndev);

+ enetc_mdio_remove(pf);
enetc_of_put_phy(priv);

enetc_free_msix(priv);
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.h b/drivers/net/ethernet/freescale/enetc/enetc_pf.h
index 2061ae5..10dd1b5 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pf.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.h
@@ -42,8 +42,14 @@ struct enetc_pf {
char vlan_promisc_simap; /* bitmap of SIs in VLAN promisc mode */
DECLARE_BITMAP(vlan_ht_filter, ENETC_VLAN_HT_SIZE);
DECLARE_BITMAP(active_vlans, VLAN_N_VID);
+
+ struct mii_bus *mdio; /* saved for cleanup */
};

int enetc_msg_psi_init(struct enetc_pf *pf);
void enetc_msg_psi_free(struct enetc_pf *pf);
void enetc_msg_handle_rxmsg(struct enetc_pf *pf, int mbox_id, u16 *status);
+
+/* MDIO */
+int enetc_mdio_probe(struct enetc_pf *pf);
+void enetc_mdio_remove(struct enetc_pf *pf);
--
2.7.4