ptp: Added a clock driver for the IXP46x.

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: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: John Stultz <john.stultz@linaro.org>
Acked-by: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: John Stultz <john.stultz@linaro.org>

1 files changed, 192 insertions, 3 deletions

diff --git a/drivers/net/arm/ixp4xx_eth.c b/drivers/net/arm/ixp4xx_eth.c
index 9eb9b98a7ae3..de51e8453c13 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 +255,172 @@ 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 seqid)
+{
+        u8 *data = skb->data;
+        unsigned int offset;
+        u16 *hi, *id;
+        u32 lo;
+
+        if (sk_run_filter(skb, ptp_filter) != PTP_CLASS_V1_IPV4)
+                return 0;
+
+        offset = ETH_HLEN + IPV4_HLEN(data) + UDP_HLEN;
+
+        if (skb->len < offset + OFF_PTP_SEQUENCE_ID + sizeof(seqid))
+                return 0;
+
+        hi = (u16 *)(data + offset + OFF_PTP_SOURCE_UUID);
+        id = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID);
+
+        memcpy(&lo, &hi[1], sizeof(lo));
+
+        return (uid_hi == ntohs(*hi) &&
+                uid_lo == ntohl(lo) &&
+                seqid  == ntohs(*id));
+}
+
+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 +748,7 @@ 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 +855,12 @@ 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 +902,13 @@ 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 +964,9 @@ 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 +1355,11 @@ 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;