[RFC PATCH v2 1/2] macb: Add 1588 support in Cadence GEM.
From: Andrei Pistirica
Date: Fri Nov 18 2016 - 09:25:47 EST
Cadence GEM provides a 102 bit time counter with 48 bits for seconds,
30 bits for nsecs and 24 bits for sub-nsecs to control 1588 timestamping.
This patch does the following:
- Registers to ptp clock framework
- Timer initialization is done by writing time of day to the timer counter.
- ns increment register is programmed as NSEC_PER_SEC/TSU_CLK.
For a 16 bit subns precision, the subns increment equals
remainder of (NS_PER_SEC/TSU_CLK) * (2^16).
- HW time stamp capabilities are advertised via ethtool and macb ioctl is
updated accordingly.
- Timestamps are obtained from the TX/RX PTP event/PEER registers.
The timestamp obtained thus is updated in skb for upper layers to access.
- The drivers register functions with ptp to perform time and frequency
adjustment.
- Time adjustment is done by writing to the 1558_ADJUST register.
The controller will read the delta in this register and update the timer
counter register. Alternatively, for large time offset adjustments,
the driver reads the secs and nsecs counter values, adds/subtracts the
delta and updates the timer counter.
- Frequency adjustment is not directly supported by this IP.
addend is the initial value ns increment and similarly addendesub.
The ppb (parts per billion) provided is used as
ns_incr = addend +/- (ppb/rate).
Similarly the remainder of the above is used to populate subns increment.
In case the ppb requested is negative AND subns adjustment greater than
the addendsub, ns_incr is reduced by 1 and subns_incr is adjusted in
positive accordingly.
Signed-off-by: Andrei Pistirica <andrei.pistirica@xxxxxxxxxxxxx>
Signed-off-by: Harini Katakam <harinik@xxxxxxxxxx>
---
Version 2 patch for: https://patchwork.kernel.org/patch/9310989/.
Modifications:
- bitfields for TSU are named according to SAMA5D2 data sheet
- identify GEM-PTP support based on platform capability
- add spinlock for TSU access
- change macb_ptp_adjfreq and use fewer 64bit divisions
drivers/net/ethernet/cadence/Kconfig | 10 +-
drivers/net/ethernet/cadence/Makefile | 8 +-
drivers/net/ethernet/cadence/macb.h | 80 +++++++++++
drivers/net/ethernet/cadence/macb_ptp.c | 229 ++++++++++++++++++++++++++++++++
4 files changed, 325 insertions(+), 2 deletions(-)
create mode 100644 drivers/net/ethernet/cadence/macb_ptp.c
diff --git a/drivers/net/ethernet/cadence/Kconfig b/drivers/net/ethernet/cadence/Kconfig
index f0bcb15..ebbc65f 100644
--- a/drivers/net/ethernet/cadence/Kconfig
+++ b/drivers/net/ethernet/cadence/Kconfig
@@ -29,6 +29,14 @@ config MACB
support for the MACB/GEM chip.
To compile this driver as a module, choose M here: the module
- will be called macb.
+ will be called cadence-macb.
+
+config MACB_USE_HWSTAMP
+ bool "Use IEEE 1588 hwstamp"
+ depends on MACB
+ default y
+ select PTP_1588_CLOCK
+ ---help---
+ Enable IEEE 1588 Precision Time Protocol (PTP) support for MACB.
endif # NET_CADENCE
diff --git a/drivers/net/ethernet/cadence/Makefile b/drivers/net/ethernet/cadence/Makefile
index 91f79b1..4402d42 100644
--- a/drivers/net/ethernet/cadence/Makefile
+++ b/drivers/net/ethernet/cadence/Makefile
@@ -2,4 +2,10 @@
# Makefile for the Atmel network device drivers.
#
-obj-$(CONFIG_MACB) += macb.o
+cadence-macb-y := macb.o
+
+ifeq ($(CONFIG_MACB_USE_HWSTAMP),y)
+cadence-macb-y += macb_ptp.o
+endif
+
+obj-$(CONFIG_MACB) += cadence-macb.o
diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index 3f385ab..2ee9af8 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -10,6 +10,10 @@
#ifndef _MACB_H
#define _MACB_H
+#include <linux/net_tstamp.h>
+#include <linux/ptp_clock.h>
+#include <linux/ptp_clock_kernel.h>
+
#define MACB_GREGS_NBR 16
#define MACB_GREGS_VERSION 2
#define MACB_MAX_QUEUES 8
@@ -129,6 +133,20 @@
#define GEM_RXIPCCNT 0x01a8 /* IP header Checksum Error Counter */
#define GEM_RXTCPCCNT 0x01ac /* TCP Checksum Error Counter */
#define GEM_RXUDPCCNT 0x01b0 /* UDP Checksum Error Counter */
+#define GEM_TISUBN 0x01bc /* 1588 Timer Increment Sub-ns */
+#define GEM_TSH 0x01c0 /* 1588 Timer Seconds High */
+#define GEM_TSL 0x01d0 /* 1588 Timer Seconds Low */
+#define GEM_TN 0x01d4 /* 1588 Timer Nanoseconds */
+#define GEM_TA 0x01d8 /* 1588 Timer Adjust */
+#define GEM_TI 0x01dc /* 1588 Timer Increment */
+#define GEM_EFTSL 0x01e0 /* PTP Event Frame Tx Seconds Low */
+#define GEM_EFTN 0x01e4 /* PTP Event Frame Tx Nanoseconds */
+#define GEM_EFRSL 0x01e8 /* PTP Event Frame Rx Seconds Low */
+#define GEM_EFRN 0x01ec /* PTP Event Frame Rx Nanoseconds */
+#define GEM_PEFTSL 0x01f0 /* PTP Peer Event Frame Tx Secs Low */
+#define GEM_PEFTN 0x01f4 /* PTP Peer Event Frame Tx Ns */
+#define GEM_PEFRSL 0x01f8 /* PTP Peer Event Frame Rx Sec Low */
+#define GEM_PEFRN 0x01fc /* PTP Peer Event Frame Rx Ns */
#define GEM_DCFG1 0x0280 /* Design Config 1 */
#define GEM_DCFG2 0x0284 /* Design Config 2 */
#define GEM_DCFG3 0x0288 /* Design Config 3 */
@@ -171,6 +189,7 @@
#define MACB_NCR_TPF_SIZE 1
#define MACB_TZQ_OFFSET 12 /* Transmit zero quantum pause frame */
#define MACB_TZQ_SIZE 1
+#define MACB_SRTSM_OFFSET 15
/* Bitfields in NCFGR */
#define MACB_SPD_OFFSET 0 /* Speed */
@@ -312,6 +331,36 @@
#define MACB_PFR_SIZE 1
#define MACB_PTZ_OFFSET 13 /* Enable pause time zero interrupt */
#define MACB_PTZ_SIZE 1
+#define MACB_PFTR_OFFSET 14 /* Pause Frame Transmitted */
+#define MACB_PFTR_SIZE 1
+#define MACB_DRQFR_OFFSET 18 /* PTP Delay Request Frame Received */
+#define MACB_DRQFR_SIZE 1
+#define MACB_SFR_OFFSET 19 /* PTP Sync Frame Received */
+#define MACB_SFR_SIZE 1
+#define MACB_DRQFT_OFFSET 20 /* PTP Delay Request Frame Transmitted */
+#define MACB_DRQFT_SIZE 1
+#define MACB_SFT_OFFSET 21 /* PTP Sync Frame Transmitted */
+#define MACB_SFT_SIZE 1
+#define MACB_PDRQFR_OFFSET 22 /* PDelay Request Frame Received */
+#define MACB_PDRQFR_SIZE 1
+#define MACB_PDRSFR_OFFSET 23 /* PDelay Response Frame Received */
+#define MACB_PDRSFR_SIZE 1
+#define MACB_PDRQFT_OFFSET 24 /* PDelay Request Frame Transmitted */
+#define MACB_PDRQFT_SIZE 1
+#define MACB_PDRSFT_OFFSET 25 /* PDelay Response Frame Transmitted */
+#define MACB_PDRSFT_SIZE 1
+#define MACB_SRI_OFFSET 26 /* TSU Seconds Register Increment */
+#define MACB_SRI_SIZE 1
+#define MACB_WOL_OFFSET 28 /* Wake On LAN */
+#define MACB_WOL_SIZE 1
+
+/* Timer increment fields */
+#define MACB_TI_CNS_OFFSET 0
+#define MACB_TI_CNS_SIZE 8
+#define MACB_TI_ACNS_OFFSET 8
+#define MACB_TI_ACNS_SIZE 8
+#define MACB_TI_NIT_OFFSET 16
+#define MACB_TI_NIT_SIZE 8
/* Bitfields in MAN */
#define MACB_DATA_OFFSET 0 /* data */
@@ -375,6 +424,18 @@
#define GEM_TX_PKT_BUFF_OFFSET 21
#define GEM_TX_PKT_BUFF_SIZE 1
+/* Bitfields in TISUBN */
+#define GEM_SUBNSINCR_OFFSET 0
+#define GEM_SUBNSINCR_SIZE 16
+
+/* Bitfields in TI */
+#define GEM_NSINCR_OFFSET 0
+#define GEM_NSINCR_SIZE 8
+
+/* Bitfields in ADJ */
+#define GEM_ADDSUB_OFFSET 31
+#define GEM_ADDSUB_SIZE 1
+
/* Constants for CLK */
#define MACB_CLK_DIV8 0
#define MACB_CLK_DIV16 1
@@ -405,6 +466,7 @@
#define MACB_CAPS_SG_DISABLED 0x40000000
#define MACB_CAPS_MACB_IS_GEM 0x80000000
#define MACB_CAPS_JUMBO 0x00000010
+#define MACB_CAPS_GEM_HAS_PTP 0x00000020
/* Bit manipulation macros */
#define MACB_BIT(name) \
@@ -840,8 +902,26 @@ struct macb {
unsigned int rx_frm_len_mask;
unsigned int jumbo_max_len;
+
+#ifdef CONFIG_MACB_USE_HWSTAMP
+ unsigned int hwts_tx_en;
+ unsigned int hwts_rx_en;
+ spinlock_t tsu_clk_lock;
+ unsigned int tsu_rate;
+
+ struct ptp_clock *ptp_clock;
+ struct ptp_clock_info ptp_caps;
+ unsigned int ns_incr;
+ unsigned int subns_incr;
+#endif
};
+#ifdef CONFIG_MACB_USE_HWSTAMP
+void macb_ptp_init(struct net_device *ndev);
+#else
+void macb_ptp_init(struct net_device *ndev) { }
+#endif
+
static inline bool macb_is_gem(struct macb *bp)
{
return !!(bp->caps & MACB_CAPS_MACB_IS_GEM);
diff --git a/drivers/net/ethernet/cadence/macb_ptp.c b/drivers/net/ethernet/cadence/macb_ptp.c
new file mode 100644
index 0000000..81ce3a9
--- /dev/null
+++ b/drivers/net/ethernet/cadence/macb_ptp.c
@@ -0,0 +1,229 @@
+/*
+ * PTP 1588 clock for SAMA5D2 platform.
+ *
+ * Copyright (C) 2015 Xilinx Inc.
+ * Copyright (C) 2016 Microchip Technology
+ *
+ * Authors: Harini Katakam <harinik@xxxxxxxxxx>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/etherdevice.h>
+#include <linux/platform_device.h>
+#include <linux/time64.h>
+#include <linux/ptp_classify.h>
+#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
+
+#include "macb.h"
+
+#define GMAC_TIMER_NAME "gmac-gem-ptp"
+
+static inline void macb_tsu_get_time(struct macb *bp, struct timespec64 *ts)
+{
+ u64 sec, sech, secl;
+
+ spin_lock(&bp->tsu_clk_lock);
+
+ /* get GEM internal time */
+ sech = gem_readl(bp, TSH);
+ secl = gem_readl(bp, TSL);
+ ts->tv_nsec = gem_readl(bp, TN);
+ ts->tv_sec = (sech << 32) | secl;
+
+ /* minimize the error */
+ sech = gem_readl(bp, TSH);
+ secl = gem_readl(bp, TSL);
+ sec = (sech << 32) | secl;
+ if (ts->tv_sec != sec) {
+ ts->tv_sec = sec;
+ ts->tv_nsec = gem_readl(bp, TN);
+ }
+
+ spin_unlock(&bp->tsu_clk_lock);
+}
+
+static inline void macb_tsu_set_time(struct macb *bp,
+ const struct timespec64 *ts)
+{
+ u32 ns, sech, secl;
+ s64 word_mask = 0xffffffff;
+
+ sech = (u32)ts->tv_sec;
+ secl = (u32)ts->tv_sec;
+ ns = ts->tv_nsec;
+ if (ts->tv_sec > word_mask)
+ sech = (ts->tv_sec >> 32);
+
+ spin_lock(&bp->tsu_clk_lock);
+
+ /* TSH doesn't latch the time and no atomicity! */
+ gem_writel(bp, TSH, sech);
+ gem_writel(bp, TSL, secl);
+ gem_writel(bp, TN, ns);
+
+ spin_unlock(&bp->tsu_clk_lock);
+}
+
+static int macb_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+{
+ struct macb *bp = container_of(ptp, struct macb, ptp_caps);
+ u32 addend, addend_frac, rem;
+ u64 drift_tmr, diff, diff_frac = 0;
+ int neg_adj = 0;
+
+ if (ppb < 0) {
+ neg_adj = 1;
+ ppb = -ppb;
+ }
+
+ /* drift/period */
+ drift_tmr = (bp->ns_incr * ppb) +
+ ((bp->subns_incr * ppb) >> 16);
+
+ /* drift/cycle */
+ diff = div_u64_rem(drift_tmr, 1000000000ULL, &rem);
+
+ /* drift fraction/cycle, if necessary */
+ if (rem) {
+ u64 fraction = rem;
+ fraction = fraction << 16;
+
+ diff_frac = div_u64(fraction, 1000000000ULL);
+ }
+
+ /* adjustmets */
+ addend = neg_adj ? (bp->ns_incr - diff) : (bp->ns_incr + diff);
+ addend_frac = neg_adj ? (bp->subns_incr - diff_frac) :
+ (bp->subns_incr + diff_frac);
+
+ spin_lock(&bp->tsu_clk_lock);
+
+ gem_writel(bp, TISUBN, GEM_BF(SUBNSINCR, addend_frac));
+ gem_writel(bp, TI, GEM_BF(NSINCR, addend));
+
+ spin_unlock(&bp->tsu_clk_lock);
+ return 0;
+}
+
+static int macb_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+ struct macb *bp = container_of(ptp, struct macb, ptp_caps);
+ struct timespec64 now, then = ns_to_timespec64(delta);
+ u32 adj, sign = 0;
+
+ if (delta < 0) {
+ delta = -delta;
+ sign = 1;
+ }
+
+ if (delta > 0x3FFFFFFF) {
+ macb_tsu_get_time(bp, &now);
+
+ if (sign)
+ now = timespec64_sub(now, then);
+ else
+ now = timespec64_add(now, then);
+
+ macb_tsu_set_time(bp, (const struct timespec64 *)&now);
+ } else {
+ adj = delta;
+ if (sign)
+ adj |= GEM_BIT(ADDSUB);
+
+ gem_writel(bp, TA, adj);
+ }
+
+ return 0;
+}
+
+static int macb_ptp_gettime(struct ptp_clock_info *ptp,
+ struct timespec64 *ts)
+{
+ struct macb *bp = container_of(ptp, struct macb, ptp_caps);
+
+ macb_tsu_get_time(bp, ts);
+
+ return 0;
+}
+
+static int macb_ptp_settime(struct ptp_clock_info *ptp,
+ const struct timespec64 *ts)
+{
+ struct macb *bp = container_of(ptp, struct macb, ptp_caps);
+
+ macb_tsu_set_time(bp, ts);
+
+ return 0;
+}
+
+static int macb_ptp_enable(struct ptp_clock_info *ptp,
+ struct ptp_clock_request *rq, int on)
+{
+ return -EOPNOTSUPP;
+}
+
+static struct ptp_clock_info macb_ptp_caps = {
+ .owner = THIS_MODULE,
+ .name = GMAC_TIMER_NAME,
+ .max_adj = 250000000,
+ .n_alarm = 0,
+ .n_ext_ts = 0,
+ .n_per_out = 0,
+ .n_pins = 0,
+ .pps = 0,
+ .adjfreq = macb_ptp_adjfreq,
+ .adjtime = macb_ptp_adjtime,
+ .gettime64 = macb_ptp_gettime,
+ .settime64 = macb_ptp_settime,
+ .enable = macb_ptp_enable,
+};
+
+void macb_ptp_init(struct net_device *ndev)
+{
+ struct macb *bp = netdev_priv(ndev);
+ struct timespec64 now;
+ u32 rem = 0;
+
+ if (!(bp->caps | MACB_CAPS_GEM_HAS_PTP)){
+ netdev_vdbg(bp->dev, "Platform does not support PTP!\n");
+ return;
+ }
+
+ spin_lock_init(&bp->tsu_clk_lock);
+
+ bp->ptp_caps = macb_ptp_caps;
+ bp->tsu_rate = clk_get_rate(bp->pclk);
+
+ getnstimeofday64(&now);
+ macb_tsu_set_time(bp, (const struct timespec64 *)&now);
+
+ bp->ns_incr = div_u64_rem(NSEC_PER_SEC, bp->tsu_rate, &rem);
+ if (rem) {
+ u64 adj = rem;
+ /* Multiply by 2^16 as subns register is 16 bits */
+ adj <<= 16;
+ bp->subns_incr = div_u64(adj, bp->tsu_rate);
+ } else {
+ bp->subns_incr = 0;
+ }
+
+ gem_writel(bp, TISUBN, GEM_BF(SUBNSINCR, bp->subns_incr));
+ gem_writel(bp, TI, GEM_BF(NSINCR, bp->ns_incr));
+ gem_writel(bp, TA, 0);
+
+ bp->ptp_clock = ptp_clock_register(&bp->ptp_caps, NULL);
+ if (IS_ERR(&bp->ptp_clock)) {
+ bp->ptp_clock = NULL;
+ pr_err("ptp clock register failed\n");
+ return;
+ }
+
+ dev_info(&bp->pdev->dev, "%s ptp clock registered.\n", GMAC_TIMER_NAME);
+}
+
--
1.9.1