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>

1 files changed, 108 insertions, 0 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
new file mode 100644
index 000000000000..380baeb016a9
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
@@ -0,0 +1,108 @@
+/*******************************************************************************
+  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,
+};