[V14,3/4] ptp: Added a clock driver for the IXP46x.

Submitted by Richard Cochran on April 18, 2011, 6:29 a.m.

Details

Message ID dbee2487a57fd7f41e4efbbd2ddfb1313b8d71bc.1303107532.git.richard.cochran@omicron.at
State Not Applicable
Headers show

Commit Message

Richard Cochran April 18, 2011, 6:29 a.m.
This patch adds a driver for the hardware time stamping unit found on the
IXP465. The basic clock operations and an external trigger are implemented.

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: John Stultz <john.stultz@linaro.org>
---
 arch/arm/mach-ixp4xx/include/mach/ixp46x_ts.h |   78 ++++++
 drivers/net/arm/ixp4xx_eth.c                  |  192 ++++++++++++++-
 drivers/ptp/Kconfig                           |   13 +
 drivers/ptp/Makefile                          |    1 +
 drivers/ptp/ptp_ixp46x.c                      |  332 +++++++++++++++++++++++++
 5 files changed, 613 insertions(+), 3 deletions(-)
 create mode 100644 arch/arm/mach-ixp4xx/include/mach/ixp46x_ts.h
 create mode 100644 drivers/ptp/ptp_ixp46x.c

Comments

Arnd Bergmann April 18, 2011, 6:56 a.m.
On Monday 18 April 2011, Richard Cochran wrote:
> +static void ixp_rx_timestamp(struct port *port, struct sk_buff *skb)
> +{
> +       struct skb_shared_hwtstamps *shhwtstamps;
> +       struct ixp46x_ts_regs *regs;
> +       u64 ns;
> +       u32 ch, hi, lo, val;
> +       u16 uid, seq;
> +
> +       if (!port->hwts_rx_en)
> +               return;
> +
> +       ch = PORT2CHANNEL(port);
> +
> +       regs = (struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT;
> +
> +       val = __raw_readl(&regs->channel[ch].ch_event);
> +
> +       if (!(val & RX_SNAPSHOT_LOCKED))
> +               return;
> +
> +       lo = __raw_readl(&regs->channel[ch].src_uuid_lo);
> +       hi = __raw_readl(&regs->channel[ch].src_uuid_hi);
> +

I guess you should use readl(), not __raw_readl() here. The __raw_* functions
are not meant for device drivers.

	Arnd
Richard Cochran April 18, 2011, 8:06 a.m.
On Mon, Apr 18, 2011 at 08:56:03AM +0200, Arnd Bergmann wrote:
> On Monday 18 April 2011, Richard Cochran wrote:
> > +
> > +       lo = __raw_readl(&regs->channel[ch].src_uuid_lo);
> > +       hi = __raw_readl(&regs->channel[ch].src_uuid_hi);
> > +
> 
> I guess you should use readl(), not __raw_readl() here. The __raw_* functions
> are not meant for device drivers.

Krzysztof had a different opinion about this.

    https://lkml.org/lkml/2011/1/8/67

Anyway, it is his driver, and I just followed what he does elsewhere
in the driver. It make sense to me to keep the driver consistent.
Maybe we should make the change throughout?

Thanks,
Richard
Richard Cochran April 18, 2011, 8:16 a.m.
Also, I forgot to add Krzysztof's ack to the commit message, but he
did ack V12.

Thanks,
Richard
Arnd Bergmann April 18, 2011, 8:21 a.m.
On Monday 18 April 2011, Richard Cochran wrote:
> On Mon, Apr 18, 2011 at 08:56:03AM +0200, Arnd Bergmann wrote:
> > On Monday 18 April 2011, Richard Cochran wrote:
> > > +
> > > +       lo = __raw_readl(&regs->channel[ch].src_uuid_lo);
> > > +       hi = __raw_readl(&regs->channel[ch].src_uuid_hi);
> > > +
> > 
> > I guess you should use readl(), not __raw_readl() here. The __raw_* functions
> > are not meant for device drivers.
> 
> Krzysztof had a different opinion about this.
> 
>     https://lkml.org/lkml/2011/1/8/67
> 
> Anyway, it is his driver, and I just followed what he does elsewhere
> in the driver. It make sense to me to keep the driver consistent.
> Maybe we should make the change throughout?

It would certainly be useful to fix it up. I now realized that this driver
supports both big-endian and little-endian configurations, so just using
readl() is certainly broken.
There should probably be an ixp specific version of the safe I/O accessors
to deal with it on all on-chip peripherals in a safe way.

	Arnd
Arnd Bergmann April 18, 2011, 8:26 a.m.
On Monday 18 April 2011, Arnd Bergmann wrote:
> On Monday 18 April 2011, Richard Cochran wrote:
> > On Mon, Apr 18, 2011 at 08:56:03AM +0200, Arnd Bergmann wrote:
> > > On Monday 18 April 2011, Richard Cochran wrote:
> > > > +
> > > > +       lo = __raw_readl(&regs->channel[ch].src_uuid_lo);
> > > > +       hi = __raw_readl(&regs->channel[ch].src_uuid_hi);
> > > > +
> > > 
> > > I guess you should use readl(), not __raw_readl() here. The __raw_* functions
> > > are not meant for device drivers.
> > 
> > Krzysztof had a different opinion about this.
> > 
> >     https://lkml.org/lkml/2011/1/8/67
> > 
> > Anyway, it is his driver, and I just followed what he does elsewhere
> > in the driver. It make sense to me to keep the driver consistent.
> > Maybe we should make the change throughout?
> 
> It would certainly be useful to fix it up. I now realized that this driver
> supports both big-endian and little-endian configurations, so just using
> readl() is certainly broken.
> There should probably be an ixp specific version of the safe I/O accessors
> to deal with it on all on-chip peripherals in a safe way.

Anyway, not your problem then, just leave it like it is.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Ben Hutchings April 18, 2011, 8:53 p.m.
On Mon, 2011-04-18 at 08:29 +0200, Richard Cochran wrote:
> This patch adds a driver for the hardware time stamping unit found on the
> IXP465. The basic clock operations and an external trigger are implemented.
[...]
> --- a/drivers/net/arm/ixp4xx_eth.c
> +++ b/drivers/net/arm/ixp4xx_eth.c
[...]
> @@ -246,6 +255,169 @@ static int ports_open;
>  static struct port *npe_port_tab[MAX_NPES];
>  static struct dma_pool *dma_pool;
>  
> +static struct sock_filter ptp_filter[] = {
> +	PTP_FILTER
> +};
> +
> +static int ixp_ptp_match(struct sk_buff *skb, u16 uid_hi, u32 uid_lo, u16 seq)
> +{
> +	unsigned int type;
> +	u16 *hi, *id;
> +	u8 *lo, *data = skb->data;
> +
> +	type = sk_run_filter(skb, ptp_filter);
> +
> +	if (PTP_CLASS_V1_IPV4 == type) {
> +
> +		id = (u16 *)(data + 42 + 30);
> +		hi = (u16 *)(data + 42 + 22);
> +		lo = data + 42 + 24;
[...]

PTP_FILTER does not verify that the packet length is sufficient to hold
a complete PTP header, nor does it require that the IPv4 header length
is 5 (i.e. 20 bytes).  So you have to check those here rather than using
magic numbers.

I think you also need to use be16_to_cpup() to read 'id' and 'hi', since
the host byte order may vary.

Ben.

Patch hide | download patch | download mbox

diff --git a/arch/arm/mach-ixp4xx/include/mach/ixp46x_ts.h b/arch/arm/mach-ixp4xx/include/mach/ixp46x_ts.h
new file mode 100644
index 0000000..292d55e
--- /dev/null
+++ b/arch/arm/mach-ixp4xx/include/mach/ixp46x_ts.h
@@ -0,0 +1,78 @@ 
+/*
+ * PTP 1588 clock using the IXP46X
+ *
+ * Copyright (C) 2010 OMICRON electronics GmbH
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _IXP46X_TS_H_
+#define _IXP46X_TS_H_
+
+#define DEFAULT_ADDEND 0xF0000029
+#define TICKS_NS_SHIFT 4
+
+struct ixp46x_channel_ctl {
+	u32 ch_control;  /* 0x40 Time Synchronization Channel Control */
+	u32 ch_event;    /* 0x44 Time Synchronization Channel Event */
+	u32 tx_snap_lo;  /* 0x48 Transmit Snapshot Low Register */
+	u32 tx_snap_hi;  /* 0x4C Transmit Snapshot High Register */
+	u32 rx_snap_lo;  /* 0x50 Receive Snapshot Low Register */
+	u32 rx_snap_hi;  /* 0x54 Receive Snapshot High Register */
+	u32 src_uuid_lo; /* 0x58 Source UUID0 Low Register */
+	u32 src_uuid_hi; /* 0x5C Sequence Identifier/Source UUID0 High */
+};
+
+struct ixp46x_ts_regs {
+	u32 control;     /* 0x00 Time Sync Control Register */
+	u32 event;       /* 0x04 Time Sync Event Register */
+	u32 addend;      /* 0x08 Time Sync Addend Register */
+	u32 accum;       /* 0x0C Time Sync Accumulator Register */
+	u32 test;        /* 0x10 Time Sync Test Register */
+	u32 unused;      /* 0x14 */
+	u32 rsystime_lo; /* 0x18 RawSystemTime_Low Register */
+	u32 rsystime_hi; /* 0x1C RawSystemTime_High Register */
+	u32 systime_lo;  /* 0x20 SystemTime_Low Register */
+	u32 systime_hi;  /* 0x24 SystemTime_High Register */
+	u32 trgt_lo;     /* 0x28 TargetTime_Low Register */
+	u32 trgt_hi;     /* 0x2C TargetTime_High Register */
+	u32 asms_lo;     /* 0x30 Auxiliary Slave Mode Snapshot Low  */
+	u32 asms_hi;     /* 0x34 Auxiliary Slave Mode Snapshot High */
+	u32 amms_lo;     /* 0x38 Auxiliary Master Mode Snapshot Low */
+	u32 amms_hi;     /* 0x3C Auxiliary Master Mode Snapshot High */
+
+	struct ixp46x_channel_ctl channel[3];
+};
+
+/* 0x00 Time Sync Control Register Bits */
+#define TSCR_AMM (1<<3)
+#define TSCR_ASM (1<<2)
+#define TSCR_TTM (1<<1)
+#define TSCR_RST (1<<0)
+
+/* 0x04 Time Sync Event Register Bits */
+#define TSER_SNM (1<<3)
+#define TSER_SNS (1<<2)
+#define TTIPEND  (1<<1)
+
+/* 0x40 Time Synchronization Channel Control Register Bits */
+#define MASTER_MODE   (1<<0)
+#define TIMESTAMP_ALL (1<<1)
+
+/* 0x44 Time Synchronization Channel Event Register Bits */
+#define TX_SNAPSHOT_LOCKED (1<<0)
+#define RX_SNAPSHOT_LOCKED (1<<1)
+
+#endif
diff --git a/drivers/net/arm/ixp4xx_eth.c b/drivers/net/arm/ixp4xx_eth.c
index 9eb9b98..c56fcb6 100644
--- a/drivers/net/arm/ixp4xx_eth.c
+++ b/drivers/net/arm/ixp4xx_eth.c
@@ -30,9 +30,12 @@ 
 #include <linux/etherdevice.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/net_tstamp.h>
 #include <linux/phy.h>
 #include <linux/platform_device.h>
+#include <linux/ptp_classify.h>
 #include <linux/slab.h>
+#include <mach/ixp46x_ts.h>
 #include <mach/npe.h>
 #include <mach/qmgr.h>
 
@@ -67,6 +70,10 @@ 
 #define RXFREE_QUEUE(port_id)	(NPE_ID(port_id) + 26)
 #define TXDONE_QUEUE		31
 
+#define PTP_SLAVE_MODE		1
+#define PTP_MASTER_MODE		2
+#define PORT2CHANNEL(p)		NPE_ID(p->id)
+
 /* TX Control Registers */
 #define TX_CNTRL0_TX_EN		0x01
 #define TX_CNTRL0_HALFDUPLEX	0x02
@@ -171,6 +178,8 @@  struct port {
 	int id;			/* logical port ID */
 	int speed, duplex;
 	u8 firmware[4];
+	int hwts_tx_en;
+	int hwts_rx_en;
 };
 
 /* NPE message structure */
@@ -246,6 +255,169 @@  static int ports_open;
 static struct port *npe_port_tab[MAX_NPES];
 static struct dma_pool *dma_pool;
 
+static struct sock_filter ptp_filter[] = {
+	PTP_FILTER
+};
+
+static int ixp_ptp_match(struct sk_buff *skb, u16 uid_hi, u32 uid_lo, u16 seq)
+{
+	unsigned int type;
+	u16 *hi, *id;
+	u8 *lo, *data = skb->data;
+
+	type = sk_run_filter(skb, ptp_filter);
+
+	if (PTP_CLASS_V1_IPV4 == type) {
+
+		id = (u16 *)(data + 42 + 30);
+		hi = (u16 *)(data + 42 + 22);
+		lo = data + 42 + 24;
+
+		return (uid_hi == *hi &&
+			0 == memcmp(&uid_lo, lo, sizeof(uid_lo)) &&
+			seq == *id);
+	}
+
+	return 0;
+}
+
+static void ixp_rx_timestamp(struct port *port, struct sk_buff *skb)
+{
+	struct skb_shared_hwtstamps *shhwtstamps;
+	struct ixp46x_ts_regs *regs;
+	u64 ns;
+	u32 ch, hi, lo, val;
+	u16 uid, seq;
+
+	if (!port->hwts_rx_en)
+		return;
+
+	ch = PORT2CHANNEL(port);
+
+	regs = (struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT;
+
+	val = __raw_readl(&regs->channel[ch].ch_event);
+
+	if (!(val & RX_SNAPSHOT_LOCKED))
+		return;
+
+	lo = __raw_readl(&regs->channel[ch].src_uuid_lo);
+	hi = __raw_readl(&regs->channel[ch].src_uuid_hi);
+
+	uid = hi & 0xffff;
+	seq = (hi >> 16) & 0xffff;
+
+	if (!ixp_ptp_match(skb, htons(uid), htonl(lo), htons(seq)))
+		goto out;
+
+	lo = __raw_readl(&regs->channel[ch].rx_snap_lo);
+	hi = __raw_readl(&regs->channel[ch].rx_snap_hi);
+	ns = ((u64) hi) << 32;
+	ns |= lo;
+	ns <<= TICKS_NS_SHIFT;
+
+	shhwtstamps = skb_hwtstamps(skb);
+	memset(shhwtstamps, 0, sizeof(*shhwtstamps));
+	shhwtstamps->hwtstamp = ns_to_ktime(ns);
+out:
+	__raw_writel(RX_SNAPSHOT_LOCKED, &regs->channel[ch].ch_event);
+}
+
+static void ixp_tx_timestamp(struct port *port, struct sk_buff *skb)
+{
+	struct skb_shared_hwtstamps shhwtstamps;
+	struct ixp46x_ts_regs *regs;
+	struct skb_shared_info *shtx;
+	u64 ns;
+	u32 ch, cnt, hi, lo, val;
+
+	shtx = skb_shinfo(skb);
+	if (unlikely(shtx->tx_flags & SKBTX_HW_TSTAMP && port->hwts_tx_en))
+		shtx->tx_flags |= SKBTX_IN_PROGRESS;
+	else
+		return;
+
+	ch = PORT2CHANNEL(port);
+
+	regs = (struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT;
+
+	/*
+	 * This really stinks, but we have to poll for the Tx time stamp.
+	 * Usually, the time stamp is ready after 4 to 6 microseconds.
+	 */
+	for (cnt = 0; cnt < 100; cnt++) {
+		val = __raw_readl(&regs->channel[ch].ch_event);
+		if (val & TX_SNAPSHOT_LOCKED)
+			break;
+		udelay(1);
+	}
+	if (!(val & TX_SNAPSHOT_LOCKED)) {
+		shtx->tx_flags &= ~SKBTX_IN_PROGRESS;
+		return;
+	}
+
+	lo = __raw_readl(&regs->channel[ch].tx_snap_lo);
+	hi = __raw_readl(&regs->channel[ch].tx_snap_hi);
+	ns = ((u64) hi) << 32;
+	ns |= lo;
+	ns <<= TICKS_NS_SHIFT;
+
+	memset(&shhwtstamps, 0, sizeof(shhwtstamps));
+	shhwtstamps.hwtstamp = ns_to_ktime(ns);
+	skb_tstamp_tx(skb, &shhwtstamps);
+
+	__raw_writel(TX_SNAPSHOT_LOCKED, &regs->channel[ch].ch_event);
+}
+
+static int hwtstamp_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
+{
+	struct hwtstamp_config cfg;
+	struct ixp46x_ts_regs *regs;
+	struct port *port = netdev_priv(netdev);
+	int ch;
+
+	if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
+		return -EFAULT;
+
+	if (cfg.flags) /* reserved for future extensions */
+		return -EINVAL;
+
+	ch = PORT2CHANNEL(port);
+	regs = (struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT;
+
+	switch (cfg.tx_type) {
+	case HWTSTAMP_TX_OFF:
+		port->hwts_tx_en = 0;
+		break;
+	case HWTSTAMP_TX_ON:
+		port->hwts_tx_en = 1;
+		break;
+	default:
+		return -ERANGE;
+	}
+
+	switch (cfg.rx_filter) {
+	case HWTSTAMP_FILTER_NONE:
+		port->hwts_rx_en = 0;
+		break;
+	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
+		port->hwts_rx_en = PTP_SLAVE_MODE;
+		__raw_writel(0, &regs->channel[ch].ch_control);
+		break;
+	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
+		port->hwts_rx_en = PTP_MASTER_MODE;
+		__raw_writel(MASTER_MODE, &regs->channel[ch].ch_control);
+		break;
+	default:
+		return -ERANGE;
+	}
+
+	/* Clear out any old time stamps. */
+	__raw_writel(TX_SNAPSHOT_LOCKED | RX_SNAPSHOT_LOCKED,
+		     &regs->channel[ch].ch_event);
+
+	return copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)) ? -EFAULT : 0;
+}
 
 static int ixp4xx_mdio_cmd(struct mii_bus *bus, int phy_id, int location,
 			   int write, u16 cmd)
@@ -573,6 +745,7 @@  static int eth_poll(struct napi_struct *napi, int budget)
 
 		debug_pkt(dev, "eth_poll", skb->data, skb->len);
 
+		ixp_rx_timestamp(port, skb);
 		skb->protocol = eth_type_trans(skb, dev);
 		dev->stats.rx_packets++;
 		dev->stats.rx_bytes += skb->len;
@@ -679,14 +852,12 @@  static int eth_xmit(struct sk_buff *skb, struct net_device *dev)
 		return NETDEV_TX_OK;
 	}
 	memcpy_swab32(mem, (u32 *)((int)skb->data & ~3), bytes / 4);
-	dev_kfree_skb(skb);
 #endif
 
 	phys = dma_map_single(&dev->dev, mem, bytes, DMA_TO_DEVICE);
 	if (dma_mapping_error(&dev->dev, phys)) {
-#ifdef __ARMEB__
 		dev_kfree_skb(skb);
-#else
+#ifndef __ARMEB__
 		kfree(mem);
 #endif
 		dev->stats.tx_dropped++;
@@ -728,6 +899,13 @@  static int eth_xmit(struct sk_buff *skb, struct net_device *dev)
 #if DEBUG_TX
 	printk(KERN_DEBUG "%s: eth_xmit end\n", dev->name);
 #endif
+
+	ixp_tx_timestamp(port, skb);
+	skb_tx_timestamp(skb);
+
+#ifndef __ARMEB__
+	dev_kfree_skb(skb);
+#endif
 	return NETDEV_TX_OK;
 }
 
@@ -783,6 +961,9 @@  static int eth_ioctl(struct net_device *dev, struct ifreq *req, int cmd)
 	if (!netif_running(dev))
 		return -EINVAL;
 
+	if (cpu_is_ixp46x() && cmd == SIOCSHWTSTAMP)
+		return hwtstamp_ioctl(dev, req, cmd);
+
 	return phy_mii_ioctl(port->phydev, req, cmd);
 }
 
@@ -1171,6 +1352,11 @@  static int __devinit eth_init_one(struct platform_device *pdev)
 	char phy_id[MII_BUS_ID_SIZE + 3];
 	int err;
 
+	if (ptp_filter_init(ptp_filter, ARRAY_SIZE(ptp_filter))) {
+		pr_err("ixp4xx_eth: bad ptp filter\n");
+		return -EINVAL;
+	}
+
 	if (!(dev = alloc_etherdev(sizeof(struct port))))
 		return -ENOMEM;
 
diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig
index 12eb844..fcfafd0 100644
--- a/drivers/ptp/Kconfig
+++ b/drivers/ptp/Kconfig
@@ -40,4 +40,17 @@  config PTP_1588_CLOCK_GIANFAR
 	  To compile this driver as a module, choose M here: the module
 	  will be called gianfar_ptp.
 
+config PTP_1588_CLOCK_IXP46X
+	tristate "Intel IXP46x as PTP clock"
+	depends on PTP_1588_CLOCK
+	depends on IXP4XX_ETH
+	help
+	  This driver adds support for using the IXP46X as a PTP
+	  clock. This clock is only useful if your PTP programs are
+	  getting hardware time stamps on the PTP Ethernet packets
+	  using the SO_TIMESTAMPING API.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called ptp_ixp46x.
+
 endmenu
diff --git a/drivers/ptp/Makefile b/drivers/ptp/Makefile
index 480e2af..f6933e8 100644
--- a/drivers/ptp/Makefile
+++ b/drivers/ptp/Makefile
@@ -4,3 +4,4 @@ 
 
 ptp-y					:= ptp_clock.o ptp_chardev.o ptp_sysfs.o
 obj-$(CONFIG_PTP_1588_CLOCK)		+= ptp.o
+obj-$(CONFIG_PTP_1588_CLOCK_IXP46X)	+= ptp_ixp46x.o
diff --git a/drivers/ptp/ptp_ixp46x.c b/drivers/ptp/ptp_ixp46x.c
new file mode 100644
index 0000000..803d665
--- /dev/null
+++ b/drivers/ptp/ptp_ixp46x.c
@@ -0,0 +1,332 @@ 
+/*
+ * PTP 1588 clock using the IXP46X
+ *
+ * Copyright (C) 2010 OMICRON electronics GmbH
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/ptp_clock_kernel.h>
+#include <mach/ixp46x_ts.h>
+
+#define DRIVER		"ptp_ixp46x"
+#define N_EXT_TS	2
+#define MASTER_GPIO	8
+#define MASTER_IRQ	25
+#define SLAVE_GPIO	7
+#define SLAVE_IRQ	24
+
+struct ixp_clock {
+	struct ixp46x_ts_regs *regs;
+	struct ptp_clock *ptp_clock;
+	struct ptp_clock_info caps;
+	int exts0_enabled;
+	int exts1_enabled;
+};
+
+DEFINE_SPINLOCK(register_lock);
+
+/*
+ * Register access functions
+ */
+
+static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
+{
+	u64 ns;
+	u32 lo, hi;
+
+	lo = __raw_readl(&regs->systime_lo);
+	hi = __raw_readl(&regs->systime_hi);
+
+	ns = ((u64) hi) << 32;
+	ns |= lo;
+	ns <<= TICKS_NS_SHIFT;
+
+	return ns;
+}
+
+static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns)
+{
+	u32 hi, lo;
+
+	ns >>= TICKS_NS_SHIFT;
+	hi = ns >> 32;
+	lo = ns & 0xffffffff;
+
+	__raw_writel(lo, &regs->systime_lo);
+	__raw_writel(hi, &regs->systime_hi);
+}
+
+/*
+ * Interrupt service routine
+ */
+
+static irqreturn_t isr(int irq, void *priv)
+{
+	struct ixp_clock *ixp_clock = priv;
+	struct ixp46x_ts_regs *regs = ixp_clock->regs;
+	struct ptp_clock_event event;
+	u32 ack = 0, lo, hi, val;
+
+	val = __raw_readl(&regs->event);
+
+	if (val & TSER_SNS) {
+		ack |= TSER_SNS;
+		if (ixp_clock->exts0_enabled) {
+			hi = __raw_readl(&regs->asms_hi);
+			lo = __raw_readl(&regs->asms_lo);
+			event.type = PTP_CLOCK_EXTTS;
+			event.index = 0;
+			event.timestamp = ((u64) hi) << 32;
+			event.timestamp |= lo;
+			event.timestamp <<= TICKS_NS_SHIFT;
+			ptp_clock_event(ixp_clock->ptp_clock, &event);
+		}
+	}
+
+	if (val & TSER_SNM) {
+		ack |= TSER_SNM;
+		if (ixp_clock->exts1_enabled) {
+			hi = __raw_readl(&regs->amms_hi);
+			lo = __raw_readl(&regs->amms_lo);
+			event.type = PTP_CLOCK_EXTTS;
+			event.index = 1;
+			event.timestamp = ((u64) hi) << 32;
+			event.timestamp |= lo;
+			event.timestamp <<= TICKS_NS_SHIFT;
+			ptp_clock_event(ixp_clock->ptp_clock, &event);
+		}
+	}
+
+	if (val & TTIPEND)
+		ack |= TTIPEND; /* this bit seems to be always set */
+
+	if (ack) {
+		__raw_writel(ack, &regs->event);
+		return IRQ_HANDLED;
+	} else
+		return IRQ_NONE;
+}
+
+/*
+ * PTP clock operations
+ */
+
+static int ptp_ixp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+{
+	u64 adj;
+	u32 diff, addend;
+	int neg_adj = 0;
+	struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
+	struct ixp46x_ts_regs *regs = ixp_clock->regs;
+
+	if (ppb < 0) {
+		neg_adj = 1;
+		ppb = -ppb;
+	}
+	addend = DEFAULT_ADDEND;
+	adj = addend;
+	adj *= ppb;
+	diff = div_u64(adj, 1000000000ULL);
+
+	addend = neg_adj ? addend - diff : addend + diff;
+
+	__raw_writel(addend, &regs->addend);
+
+	return 0;
+}
+
+static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+	s64 now;
+	unsigned long flags;
+	struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
+	struct ixp46x_ts_regs *regs = ixp_clock->regs;
+
+	spin_lock_irqsave(&register_lock, flags);
+
+	now = ixp_systime_read(regs);
+	now += delta;
+	ixp_systime_write(regs, now);
+
+	spin_unlock_irqrestore(&register_lock, flags);
+
+	return 0;
+}
+
+static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
+{
+	u64 ns;
+	u32 remainder;
+	unsigned long flags;
+	struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
+	struct ixp46x_ts_regs *regs = ixp_clock->regs;
+
+	spin_lock_irqsave(&register_lock, flags);
+
+	ns = ixp_systime_read(regs);
+
+	spin_unlock_irqrestore(&register_lock, flags);
+
+	ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
+	ts->tv_nsec = remainder;
+	return 0;
+}
+
+static int ptp_ixp_settime(struct ptp_clock_info *ptp,
+			   const struct timespec *ts)
+{
+	u64 ns;
+	unsigned long flags;
+	struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
+	struct ixp46x_ts_regs *regs = ixp_clock->regs;
+
+	ns = ts->tv_sec * 1000000000ULL;
+	ns += ts->tv_nsec;
+
+	spin_lock_irqsave(&register_lock, flags);
+
+	ixp_systime_write(regs, ns);
+
+	spin_unlock_irqrestore(&register_lock, flags);
+
+	return 0;
+}
+
+static int ptp_ixp_enable(struct ptp_clock_info *ptp,
+			  struct ptp_clock_request *rq, int on)
+{
+	struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
+
+	switch (rq->type) {
+	case PTP_CLK_REQ_EXTTS:
+		switch (rq->extts.index) {
+		case 0:
+			ixp_clock->exts0_enabled = on ? 1 : 0;
+			break;
+		case 1:
+			ixp_clock->exts1_enabled = on ? 1 : 0;
+			break;
+		default:
+			return -EINVAL;
+		}
+		return 0;
+	default:
+		break;
+	}
+
+	return -EOPNOTSUPP;
+}
+
+static struct ptp_clock_info ptp_ixp_caps = {
+	.owner		= THIS_MODULE,
+	.name		= "IXP46X timer",
+	.max_adj	= 66666655,
+	.n_ext_ts	= N_EXT_TS,
+	.pps		= 0,
+	.adjfreq	= ptp_ixp_adjfreq,
+	.adjtime	= ptp_ixp_adjtime,
+	.gettime	= ptp_ixp_gettime,
+	.settime	= ptp_ixp_settime,
+	.enable		= ptp_ixp_enable,
+};
+
+/* module operations */
+
+static struct ixp_clock ixp_clock;
+
+static int setup_interrupt(int gpio)
+{
+	int irq;
+
+	gpio_line_config(gpio, IXP4XX_GPIO_IN);
+
+	irq = gpio_to_irq(gpio);
+
+	if (NO_IRQ == irq)
+		return NO_IRQ;
+
+	if (irq_set_irq_type(irq, IRQF_TRIGGER_FALLING)) {
+		pr_err("cannot set trigger type for irq %d\n", irq);
+		return NO_IRQ;
+	}
+
+	if (request_irq(irq, isr, 0, DRIVER, &ixp_clock)) {
+		pr_err("request_irq failed for irq %d\n", irq);
+		return NO_IRQ;
+	}
+
+	return irq;
+}
+
+static void __exit ptp_ixp_exit(void)
+{
+	free_irq(MASTER_IRQ, &ixp_clock);
+	free_irq(SLAVE_IRQ, &ixp_clock);
+	ptp_clock_unregister(ixp_clock.ptp_clock);
+}
+
+static int __init ptp_ixp_init(void)
+{
+	if (!cpu_is_ixp46x())
+		return -ENODEV;
+
+	ixp_clock.regs =
+		(struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT;
+
+	ixp_clock.caps = ptp_ixp_caps;
+
+	ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps);
+
+	if (IS_ERR(ixp_clock.ptp_clock))
+		return PTR_ERR(ixp_clock.ptp_clock);
+
+	__raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend);
+	__raw_writel(1, &ixp_clock.regs->trgt_lo);
+	__raw_writel(0, &ixp_clock.regs->trgt_hi);
+	__raw_writel(TTIPEND, &ixp_clock.regs->event);
+
+	if (MASTER_IRQ != setup_interrupt(MASTER_GPIO)) {
+		pr_err("failed to setup gpio %d as irq\n", MASTER_GPIO);
+		goto no_master;
+	}
+	if (SLAVE_IRQ != setup_interrupt(SLAVE_GPIO)) {
+		pr_err("failed to setup gpio %d as irq\n", SLAVE_GPIO);
+		goto no_slave;
+	}
+
+	return 0;
+no_slave:
+	free_irq(MASTER_IRQ, &ixp_clock);
+no_master:
+	ptp_clock_unregister(ixp_clock.ptp_clock);
+	return -ENODEV;
+}
+
+module_init(ptp_ixp_init);
+module_exit(ptp_ixp_exit);
+
+MODULE_AUTHOR("Richard Cochran <richard.cochran@omicron.at>");
+MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
+MODULE_LICENSE("GPL");