stmmac: add IEEE PTPv1 and PTPv2 support.

This patch enhances the stmmac driver to support IEEE 1588-2002
PTP (Precision Time Protocol) version 1 and IEEE 1588-2008 PPT
version 2.

Precision Time Protocol(PTP),which enables precise synchronization
of clocks in measurement and control systems implemented with
technologies such as network communication,local computing,
& distributed objects.

Both PTPv1 and PTPv2 is selected at run-time using the HW capability
register.

The PTPv1 TimeStamp support can be used on chips that have the normal
descriptor structures and PTPv2 TimeStamp support can be used on chips
that have the Extended descriptors(DES4-5-6-7). All such sanity checks
are done and verified by using HW capability register.

V2: in this version the ethtool support has been included in this patch;
Koptions have been completely removed (previously added to select
PTP and PTPv2). PTPv1 and PTPv2 is now added in a single patch instead of
two patches.
get_timestamp() and get_systemtime() L/H have been combined into single APIs.
Signed-off-by: Rayagond Kokatanur <rayagond@vayavyalabs.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/Makefile

@@ -4,4 +4,4 @@ stmmac-$(CONFIG_STMMAC_PCI) += stmmac_pci.o
 stmmac-objs:= stmmac_main.o stmmac_ethtool.o stmmac_mdio.o ring_mode.o	\
 	      chain_mode.o dwmac_lib.o dwmac1000_core.o  dwmac1000_dma.o \
 	      dwmac100_core.o dwmac100_dma.o enh_desc.o  norm_desc.o \
-	      mmc_core.o $(stmmac-y)
+	      mmc_core.o stmmac_hwtstamp.o $(stmmac-y)

drivers/net/ethernet/stmicro/stmmac/chain_mode.c

@@ -122,8 +122,40 @@ static void stmmac_init_dma_chain(void *des, dma_addr_t phy_addr,
 	}
 }
 
+static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p)
+{
+	struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
+
+	if (priv->hwts_rx_en && !priv->extend_desc)
+		/* NOTE: Device will overwrite des3 with timestamp value if
+		 * 1588-2002 time stamping is enabled, hence reinitialize it
+		 * to keep explicit chaining in the descriptor.
+		 */
+		p->des3 = (unsigned int)(priv->dma_rx_phy +
+					 (((priv->dirty_rx) + 1) %
+					 priv->dma_rx_size) *
+					 sizeof(struct dma_desc));
+}
+
+static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p)
+{
+	struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
+
+	if (priv->hw->desc->get_tx_ls(p) && !priv->extend_desc)
+		/* NOTE: Device will overwrite des3 with timestamp value if
+		 * 1588-2002 time stamping is enabled, hence reinitialize it
+		 * to keep explicit chaining in the descriptor.
+		 */
+		p->des3 = (unsigned int)(priv->dma_tx_phy +
+					 (((priv->dirty_tx + 1) %
+					 priv->dma_tx_size) *
+					 sizeof(struct dma_desc)));
+}
+
 const struct stmmac_chain_mode_ops chain_mode_ops = {
 	.init = stmmac_init_dma_chain,
 	.is_jumbo_frm = stmmac_is_jumbo_frm,
 	.jumbo_frm = stmmac_jumbo_frm,
+	.refill_desc3 = stmmac_refill_desc3,
+	.clean_desc3 = stmmac_clean_desc3,
 };

drivers/net/ethernet/stmicro/stmmac/common.h

@@ -339,6 +339,14 @@ struct stmmac_desc_ops {
 			  struct dma_desc *p);
 	void (*rx_extended_status) (void *data, struct stmmac_extra_stats *x,
 				    struct dma_extended_desc *p);
+	/* Set tx timestamp enable bit */
+	void (*enable_tx_timestamp) (struct dma_desc *p);
+	/* get tx timestamp status */
+	int (*get_tx_timestamp_status) (struct dma_desc *p);
+	/* get timestamp value */
+	u64 (*get_timestamp) (void *desc, u32 ats);
+	/* get rx timestamp status */
+	int (*get_rx_timestamp_status) (void *desc, u32 ats);
 };
 
 struct stmmac_dma_ops {
@@ -398,6 +406,13 @@ struct stmmac_ops {
 	void (*get_adv) (void __iomem *ioaddr, struct rgmii_adv *adv);
 };
 
+struct stmmac_hwtimestamp {
+	void (*config_hw_tstamping) (void __iomem *ioaddr, u32 data);
+	void (*config_sub_second_increment) (void __iomem *ioaddr);
+	int (*init_systime) (void __iomem *ioaddr, u32 sec, u32 nsec);
+	int (*config_addend)(void __iomem *ioaddr, u32 addend);
+};
+
 struct mac_link {
 	int port;
 	int duplex;
@@ -412,9 +427,9 @@ struct mii_regs {
 struct stmmac_ring_mode_ops {
 	unsigned int (*is_jumbo_frm) (int len, int ehn_desc);
 	unsigned int (*jumbo_frm) (void *priv, struct sk_buff *skb, int csum);
-	void (*refill_desc3) (int bfsize, struct dma_desc *p);
+	void (*refill_desc3) (void *priv, struct dma_desc *p);
 	void (*init_desc3) (struct dma_desc *p);
-	void (*clean_desc3) (struct dma_desc *p);
+	void (*clean_desc3) (void *priv, struct dma_desc *p);
 	int (*set_16kib_bfsize) (int mtu);
 };
 
@@ -423,6 +438,8 @@ struct stmmac_chain_mode_ops {
 		      unsigned int extend_desc);
 	unsigned int (*is_jumbo_frm) (int len, int ehn_desc);
 	unsigned int (*jumbo_frm) (void *priv, struct sk_buff *skb, int csum);
+	void (*refill_desc3) (void *priv, struct dma_desc *p);
+	void (*clean_desc3) (void *priv, struct dma_desc *p);
 };
 
 struct mac_device_info {
@@ -431,6 +448,7 @@ struct mac_device_info {
 	const struct stmmac_dma_ops	*dma;
 	const struct stmmac_ring_mode_ops	*ring;
 	const struct stmmac_chain_mode_ops	*chain;
+	const struct stmmac_hwtimestamp *ptp;
 	struct mii_regs mii;	/* MII register Addresses */
 	struct mac_link link;
 	unsigned int synopsys_uid;

drivers/net/ethernet/stmicro/stmmac/enh_desc.c

@@ -378,6 +378,49 @@ static int enh_desc_get_rx_frame_len(struct dma_desc *p, int rx_coe_type)
 		return p->des01.erx.frame_length;
 }
 
+static void enh_desc_enable_tx_timestamp(struct dma_desc *p)
+{
+	p->des01.etx.time_stamp_enable = 1;
+}
+
+static int enh_desc_get_tx_timestamp_status(struct dma_desc *p)
+{
+	return p->des01.etx.time_stamp_status;
+}
+
+static u64 enh_desc_get_timestamp(void *desc, u32 ats)
+{
+	u64 ns;
+
+	if (ats) {
+		struct dma_extended_desc *p = (struct dma_extended_desc *)desc;
+		ns = p->des6;
+		/* convert high/sec time stamp value to nanosecond */
+		ns += p->des7 * 1000000000ULL;
+	} else {
+		struct dma_desc *p = (struct dma_desc *)desc;
+		ns = p->des2;
+		ns += p->des3 * 1000000000ULL;
+	}
+
+	return ns;
+}
+
+static int enh_desc_get_rx_timestamp_status(void *desc, u32 ats)
+{
+	if (ats) {
+		struct dma_extended_desc *p = (struct dma_extended_desc *)desc;
+		return p->basic.des01.erx.ipc_csum_error;
+	} else {
+		struct dma_desc *p = (struct dma_desc *)desc;
+		if ((p->des2 == 0xffffffff) && (p->des3 == 0xffffffff))
+			/* timestamp is corrupted, hence don't store it */
+			return 0;
+		else
+			return 1;
+	}
+}
+
 const struct stmmac_desc_ops enh_desc_ops = {
 	.tx_status = enh_desc_get_tx_status,
 	.rx_status = enh_desc_get_rx_status,
@@ -395,4 +438,8 @@ const struct stmmac_desc_ops enh_desc_ops = {
 	.set_rx_owner = enh_desc_set_rx_owner,
 	.get_rx_frame_len = enh_desc_get_rx_frame_len,
 	.rx_extended_status = enh_desc_get_ext_status,
+	.enable_tx_timestamp = enh_desc_enable_tx_timestamp,
+	.get_tx_timestamp_status = enh_desc_get_tx_timestamp_status,
+	.get_timestamp = enh_desc_get_timestamp,
+	.get_rx_timestamp_status = enh_desc_get_rx_timestamp_status,
 };

drivers/net/ethernet/stmicro/stmmac/norm_desc.c

@@ -219,6 +219,39 @@ static int ndesc_get_rx_frame_len(struct dma_desc *p, int rx_coe_type)
 		return p->des01.rx.frame_length;
 }
 
+static void ndesc_enable_tx_timestamp(struct dma_desc *p)
+{
+	p->des01.tx.time_stamp_enable = 1;
+}
+
+static int ndesc_get_tx_timestamp_status(struct dma_desc *p)
+{
+	return p->des01.tx.time_stamp_status;
+}
+
+static u64 ndesc_get_timestamp(void *desc, u32 ats)
+{
+	struct dma_desc *p = (struct dma_desc *)desc;
+	u64 ns;
+
+	ns = p->des2;
+	/* convert high/sec time stamp value to nanosecond */
+	ns += p->des3 * 1000000000ULL;
+
+	return ns;
+}
+
+static int ndesc_get_rx_timestamp_status(void *desc, u32 ats)
+{
+	struct dma_desc *p = (struct dma_desc *)desc;
+
+	if ((p->des2 == 0xffffffff) && (p->des3 == 0xffffffff))
+		/* timestamp is corrupted, hence don't store it */
+		return 0;
+	else
+		return 1;
+}
+
 const struct stmmac_desc_ops ndesc_ops = {
 	.tx_status = ndesc_get_tx_status,
 	.rx_status = ndesc_get_rx_status,
@@ -235,4 +268,8 @@ const struct stmmac_desc_ops ndesc_ops = {
 	.set_tx_owner = ndesc_set_tx_owner,
 	.set_rx_owner = ndesc_set_rx_owner,
 	.get_rx_frame_len = ndesc_get_rx_frame_len,
+	.enable_tx_timestamp = ndesc_enable_tx_timestamp,
+	.get_tx_timestamp_status = ndesc_get_tx_timestamp_status,
+	.get_timestamp = ndesc_get_timestamp,
+	.get_rx_timestamp_status = ndesc_get_rx_timestamp_status,
 };

drivers/net/ethernet/stmicro/stmmac/ring_mode.c

@@ -87,11 +87,14 @@ static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc)
 	return ret;
 }
 
-static void stmmac_refill_desc3(int bfsize, struct dma_desc *p)
+static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p)
 {
-	/* Fill DES3 in case of RING mode */
-	if (bfsize >= BUF_SIZE_8KiB)
-		p->des3 = p->des2 + BUF_SIZE_8KiB;
+	struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
+
+	if (unlikely(priv->plat->has_gmac))
+		/* Fill DES3 in case of RING mode */
+		if (priv->dma_buf_sz >= BUF_SIZE_8KiB)
+			p->des3 = p->des2 + BUF_SIZE_8KiB;
 }
 
 /* In ring mode we need to fill the desc3 because it is used as buffer */
@@ -100,7 +103,7 @@ static void stmmac_init_desc3(struct dma_desc *p)
 	p->des3 = p->des2 + BUF_SIZE_8KiB;
 }
 
-static void stmmac_clean_desc3(struct dma_desc *p)
+static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p)
 {
 	if (unlikely(p->des3))
 		p->des3 = 0;

drivers/net/ethernet/stmicro/stmmac/stmmac.h

@@ -99,6 +99,10 @@ struct stmmac_priv {
 	unsigned int mode;
 	int extend_desc;
 	int pcs;
+	int hwts_tx_en;
+	int hwts_rx_en;
+	unsigned int default_addend;
+	u32 adv_ts;
 };
 
 extern int phyaddr;
@@ -108,6 +112,7 @@ extern int stmmac_mdio_register(struct net_device *ndev);
 extern void stmmac_set_ethtool_ops(struct net_device *netdev);
 extern const struct stmmac_desc_ops enh_desc_ops;
 extern const struct stmmac_desc_ops ndesc_ops;
+extern const struct stmmac_hwtimestamp stmmac_ptp;
 int stmmac_freeze(struct net_device *ndev);
 int stmmac_restore(struct net_device *ndev);
 int stmmac_resume(struct net_device *ndev);

drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c

@@ -27,6 +27,7 @@
 #include <linux/interrupt.h>
 #include <linux/mii.h>
 #include <linux/phy.h>
+#include <linux/net_tstamp.h>
 #include <asm/io.h>
 
 #include "stmmac.h"
@@ -725,6 +726,35 @@ static int stmmac_set_coalesce(struct net_device *dev,
 	return 0;
 }
 
+static int stmmac_get_ts_info(struct net_device *dev,
+			      struct ethtool_ts_info *info)
+{
+	struct stmmac_priv *priv = netdev_priv(dev);
+
+	if ((priv->hwts_tx_en) && (priv->hwts_rx_en)) {
+
+		info->so_timestamping = SOF_TIMESTAMPING_TX_HARDWARE |
+					SOF_TIMESTAMPING_RX_HARDWARE |
+					SOF_TIMESTAMPING_RAW_HARDWARE;
+
+		info->tx_types = (1 << HWTSTAMP_TX_OFF) | (1 << HWTSTAMP_TX_ON);
+
+		info->rx_filters = ((1 << HWTSTAMP_FILTER_NONE) |
+				    (1 << HWTSTAMP_FILTER_PTP_V1_L4_EVENT) |
+				    (1 << HWTSTAMP_FILTER_PTP_V1_L4_SYNC) |
+				    (1 << HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ) |
+				    (1 << HWTSTAMP_FILTER_PTP_V2_L4_EVENT) |
+				    (1 << HWTSTAMP_FILTER_PTP_V2_L4_SYNC) |
+				    (1 << HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ) |
+				    (1 << HWTSTAMP_FILTER_PTP_V2_EVENT) |
+				    (1 << HWTSTAMP_FILTER_PTP_V2_SYNC) |
+				    (1 << HWTSTAMP_FILTER_PTP_V2_DELAY_REQ) |
+				    (1 << HWTSTAMP_FILTER_ALL));
+		return 0;
+	} else
+		return ethtool_op_get_ts_info(dev, info);
+}
+
 static const struct ethtool_ops stmmac_ethtool_ops = {
 	.begin = stmmac_check_if_running,
 	.get_drvinfo = stmmac_ethtool_getdrvinfo,
@@ -744,7 +774,7 @@ static const struct ethtool_ops stmmac_ethtool_ops = {
 	.get_eee = stmmac_ethtool_op_get_eee,
 	.set_eee = stmmac_ethtool_op_set_eee,
 	.get_sset_count	= stmmac_get_sset_count,
-	.get_ts_info = ethtool_op_get_ts_info,
+	.get_ts_info = stmmac_get_ts_info,
 	.get_coalesce = stmmac_get_coalesce,
 	.set_coalesce = stmmac_set_coalesce,
 };

drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c

+/*******************************************************************************
+  Copyright (C) 2013  Vayavya Labs Pvt Ltd
+
+  This implements all the API for managing HW timestamp & PTP.
+
+  This program is free software; you can redistribute it and/or modify it
+  under the terms and conditions of the GNU General Public License,
+  version 2, as published by the Free Software Foundation.
+
+  This program is distributed in the hope it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+  more details.
+
+  You should have received a copy of the GNU General Public License along with
+  this program; if not, write to the Free Software Foundation, Inc.,
+  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+
+  The full GNU General Public License is included in this distribution in
+  the file called "COPYING".
+
+  Author: Rayagond Kokatanur <rayagond@vayavyalabs.com>
+  Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
+*******************************************************************************/
+
+#include <linux/io.h>
+#include <linux/delay.h>
+#include "common.h"
+#include "stmmac_ptp.h"
+
+static void stmmac_config_hw_tstamping(void __iomem *ioaddr, u32 data)
+{
+	writel(data, ioaddr + PTP_TCR);
+}
+
+static void stmmac_config_sub_second_increment(void __iomem *ioaddr)
+{
+	u32 value = readl(ioaddr + PTP_TCR);
+	unsigned long data;
+
+	/* Convert the ptp_clock to nano second
+	 * formula = (1/ptp_clock) * 1000000000
+	 * where, ptp_clock = 50MHz.
+	 */
+	data = (1000000000ULL / 50000000);
+
+	/* 0.465ns accuracy */
+	if (value & PTP_TCR_TSCTRLSSR)
+		data = (data * 100) / 465;
+
+	writel(data, ioaddr + PTP_SSIR);
+}
+
+static int stmmac_init_systime(void __iomem *ioaddr, u32 sec, u32 nsec)
+{
+	int limit;
+	u32 value;
+
+	writel(sec, ioaddr + PTP_STSUR);
+	writel(nsec, ioaddr + PTP_STNSUR);
+	/* issue command to initialize the system time value */
+	value = readl(ioaddr + PTP_TCR);
+	value |= PTP_TCR_TSINIT;
+	writel(value, ioaddr + PTP_TCR);
+
+	/* wait for present system time initialize to complete */
+	limit = 10;
+	while (limit--) {
+		if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSINIT))
+			break;
+		mdelay(10);
+	}
+	if (limit < 0)
+		return -EBUSY;
+
+	return 0;
+}
+
+static int stmmac_config_addend(void __iomem *ioaddr, u32 addend)
+{
+	u32 value;
+	int limit;
+
+	writel(addend, ioaddr + PTP_TAR);
+	/* issue command to update the addend value */
+	value = readl(ioaddr + PTP_TCR);
+	value |= PTP_TCR_TSADDREG;
+	writel(value, ioaddr + PTP_TCR);
+
+	/* wait for present addend update to complete */
+	limit = 10;
+	while (limit--) {
+		if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSADDREG))
+			break;
+		mdelay(10);
+	}
+	if (limit < 0)
+		return -EBUSY;
+
+	return 0;
+}
+
+const struct stmmac_hwtimestamp stmmac_ptp = {
+	.config_hw_tstamping = stmmac_config_hw_tstamping,
+	.init_systime = stmmac_init_systime,
+	.config_sub_second_increment = stmmac_config_sub_second_increment,
+	.config_addend = stmmac_config_addend,
+};

drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h

+/******************************************************************************
+  PTP Header file
+
+  Copyright (C) 2013  Vayavya Labs Pvt Ltd
+
+  This program is free software; you can redistribute it and/or modify it
+  under the terms and conditions of the GNU General Public License,
+  version 2, as published by the Free Software Foundation.
+
+  This program is distributed in the hope it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+  more details.
+
+  You should have received a copy of the GNU General Public License along with
+  this program; if not, write to the Free Software Foundation, Inc.,
+  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+
+  The full GNU General Public License is included in this distribution in
+  the file called "COPYING".
+
+  Author: Rayagond Kokatanur <rayagond@vayavyalabs.com>
+******************************************************************************/
+
+#ifndef __STMMAC_PTP_H__
+#define __STMMAC_PTP_H__
+
+#define STMMAC_SYSCLOCK 62500000
+
+/* IEEE 1588 PTP register offsets */
+#define PTP_TCR		0x0700	/* Timestamp Control Reg */
+#define PTP_SSIR	0x0704	/* Sub-Second Increment Reg */
+#define PTP_STSR	0x0708	/* System Time – Seconds Regr */
+#define PTP_STNSR	0x070C	/* System Time – Nanoseconds Reg */
+#define PTP_STSUR	0x0710	/* System Time – Seconds Update Reg */
+#define PTP_STNSUR	0x0714	/* System Time – Nanoseconds Update Reg */
+#define PTP_TAR		0x0718	/* Timestamp Addend Reg */
+#define PTP_TTSR	0x071C	/* Target Time Seconds Reg */
+#define PTP_TTNSR	0x0720	/* Target Time Nanoseconds Reg */
+#define	PTP_STHWSR	0x0724	/* System Time - Higher Word Seconds Reg */
+#define PTP_TSR		0x0728	/* Timestamp Status */
+
+#define PTP_STNSUR_ADDSUB_SHIFT 31
+
+/* PTP TCR defines */
+#define PTP_TCR_TSENA		0x00000001 /* Timestamp Enable */
+#define PTP_TCR_TSCFUPDT	0x00000002 /* Timestamp Fine/Coarse Update */
+#define PTP_TCR_TSINIT		0x00000004 /* Timestamp Initialize */
+#define PTP_TCR_TSUPDT		0x00000008 /* Timestamp Update */
+/* Timestamp Interrupt Trigger Enable */
+#define PTP_TCR_TSTRIG		0x00000010
+#define PTP_TCR_TSADDREG	0x00000020 /* Addend Reg Update */
+#define PTP_TCR_TSENALL		0x00000100 /* Enable Timestamp for All Frames */
+/* Timestamp Digital or Binary Rollover Control */
+#define PTP_TCR_TSCTRLSSR	0x00000200
+
+/* Enable PTP packet Processing for Version 2 Format */
+#define PTP_TCR_TSVER2ENA	0x00000400
+/* Enable Processing of PTP over Ethernet Frames */
+#define PTP_TCR_TSIPENA		0x00000800
+/* Enable Processing of PTP Frames Sent over IPv6-UDP */
+#define PTP_TCR_TSIPV6ENA	0x00001000
+/* Enable Processing of PTP Frames Sent over IPv4-UDP */
+#define PTP_TCR_TSIPV4ENA	0x00002000
+/* Enable Timestamp Snapshot for Event Messages */
+#define PTP_TCR_TSEVNTENA	0x00004000
+/* Enable Snapshot for Messages Relevant to Master */
+#define PTP_TCR_TSMSTRENA	0x00008000
+/* Select PTP packets for Taking Snapshots */
+#define PTP_TCR_SNAPTYPSEL_1	0x00010000
+/* Enable MAC address for PTP Frame Filtering */
+#define PTP_TCR_TSENMACADDR	0x00040000
+
+#endif /* __STMMAC_PTP_H__ */