gianfar: Add hardware RX timestamping support

The device is configured to insert hardware timestamps into all
received packets. The RX timestamps are extracted from the padding
alingment bytes during the clean_rx_ring operation and copied into the
skb_shared_hwtstamps struct of the skb. This extraction only happens if
the rx_filter was set to something else than HWTSTAMP_FILTER_NONE with
the SIOCSHWTSTAMP ioctl command.

Hardware timestamping is only supported for eTSEC devices. To indicate
device support the new FSL_GIANFAR_DEV_HAS_TIMER flag was introduced.

Signed-off-by: Manfred Rudigier <manfred.rudigier@omicron.at>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 66 insertions, 5 deletions

diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index 5175233f11f2..d102484c4b36 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -82,6 +82,7 @@
 #include <linux/tcp.h>
 #include <linux/udp.h>
 #include <linux/in.h>
+#include <linux/net_tstamp.h>
 
 #include <asm/io.h>
 #include <asm/irq.h>
@@ -377,6 +378,13 @@ static void gfar_init_mac(struct net_device *ndev)
                 rctrl |= RCTRL_PADDING(priv->padding);
         }
 
+        /* Insert receive time stamps into padding alignment bytes */
+        if (priv->device_flags & FSL_GIANFAR_DEV_HAS_TIMER) {
+                rctrl &= ~RCTRL_PAL_MASK;
+                rctrl |= RCTRL_PRSDEP_INIT | RCTRL_TS_ENABLE | RCTRL_PADDING(8);
+                priv->padding = 8;
+        }
+
         /* keep vlan related bits if it's enabled */
         if (priv->vlgrp) {
                 rctrl |= RCTRL_VLEX | RCTRL_PRSDEP_INIT;
@@ -501,7 +509,8 @@ void unlock_tx_qs(struct gfar_private *priv)
 /* Returns 1 if incoming frames use an FCB */
 static inline int gfar_uses_fcb(struct gfar_private *priv)
 {
-        return priv->vlgrp || priv->rx_csum_enable;
+        return priv->vlgrp || priv->rx_csum_enable ||
+                (priv->device_flags & FSL_GIANFAR_DEV_HAS_TIMER);
 }
 
 static void free_tx_pointers(struct gfar_private *priv)
@@ -742,7 +751,8 @@ static int gfar_of_init(struct of_device *ofdev, struct net_device **pdev)
                         FSL_GIANFAR_DEV_HAS_CSUM |
                         FSL_GIANFAR_DEV_HAS_VLAN |
                         FSL_GIANFAR_DEV_HAS_MAGIC_PACKET |
-                        FSL_GIANFAR_DEV_HAS_EXTENDED_HASH;
+                        FSL_GIANFAR_DEV_HAS_EXTENDED_HASH |
+                        FSL_GIANFAR_DEV_HAS_TIMER;
 
         ctype = of_get_property(np, "phy-connection-type", NULL);
 
@@ -772,6 +782,38 @@ err_grp_init:
         return err;
 }
 
+static int gfar_hwtstamp_ioctl(struct net_device *netdev,
+                        struct ifreq *ifr, int cmd)
+{
+        struct hwtstamp_config config;
+        struct gfar_private *priv = netdev_priv(netdev);
+
+        if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
+                return -EFAULT;
+
+        /* reserved for future extensions */
+        if (config.flags)
+                return -EINVAL;
+
+        if (config.tx_type)
+                return -ERANGE;
+
+        switch (config.rx_filter) {
+        case HWTSTAMP_FILTER_NONE:
+                priv->hwts_rx_en = 0;
+                break;
+        default:
+                if (!(priv->device_flags & FSL_GIANFAR_DEV_HAS_TIMER))
+                        return -ERANGE;
+                priv->hwts_rx_en = 1;
+                config.rx_filter = HWTSTAMP_FILTER_ALL;
+                break;
+        }
+
+        return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
+                -EFAULT : 0;
+}
+
 /* Ioctl MII Interface */
 static int gfar_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 {
@@ -780,6 +822,9 @@ static int gfar_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
         if (!netif_running(dev))
                 return -EINVAL;
 
+        if (cmd == SIOCSHWTSTAMP)
+                return gfar_hwtstamp_ioctl(dev, rq, cmd);
+
         if (!priv->phydev)
                 return -ENODEV;
 
@@ -982,7 +1027,8 @@ static int gfar_probe(struct of_device *ofdev,
         else
                 priv->padding = 0;
 
-        if (dev->features & NETIF_F_IP_CSUM)
+        if (dev->features & NETIF_F_IP_CSUM ||
+                        priv->device_flags & FSL_GIANFAR_DEV_HAS_TIMER)
                 dev->hard_header_len += GMAC_FCB_LEN;
 
         /* Program the isrg regs only if number of grps > 1 */
@@ -2474,6 +2520,17 @@ static int gfar_process_frame(struct net_device *dev, struct sk_buff *skb,
                 skb_pull(skb, amount_pull);
         }
 
+        /* Get receive timestamp from the skb */
+        if (priv->hwts_rx_en) {
+                struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
+                u64 *ns = (u64 *) skb->data;
+                memset(shhwtstamps, 0, sizeof(*shhwtstamps));
+                shhwtstamps->hwtstamp = ns_to_ktime(*ns);
+        }
+
+        if (priv->padding)
+                skb_pull(skb, priv->padding);
+
         if (priv->rx_csum_enable)
                 gfar_rx_checksum(skb, fcb);
 
@@ -2510,8 +2567,7 @@ int gfar_clean_rx_ring(struct gfar_priv_rx_q *rx_queue, int rx_work_limit)
         bdp = rx_queue->cur_rx;
         base = rx_queue->rx_bd_base;
 
-        amount_pull = (gfar_uses_fcb(priv) ? GMAC_FCB_LEN : 0) +
-                priv->padding;
+        amount_pull = (gfar_uses_fcb(priv) ? GMAC_FCB_LEN : 0);
 
         while (!((bdp->status & RXBD_EMPTY) || (--rx_work_limit < 0))) {
                 struct sk_buff *newskb;
diff --git a/drivers/net/gianfar.h b/drivers/net/gianfar.h
index 17d25e714236..1ea287cba231 100644
--- a/drivers/net/gianfar.h
+++ b/drivers/net/gianfar.h
@@ -262,6 +262,7 @@ extern const char gfar_driver_version[];
 
 #define next_bd(bdp, base, ring_size) skip_bd(bdp, 1, base, ring_size)
 
+#define RCTRL_TS_ENABLE         0x01000000
 #define RCTRL_PAL_MASK          0x001f0000
 #define RCTRL_VLEX              0x00002000
 #define RCTRL_FILREN            0x00001000
@@ -885,6 +886,7 @@ struct gfar {
 #define FSL_GIANFAR_DEV_HAS_MAGIC_PACKET        0x00000100
 #define FSL_GIANFAR_DEV_HAS_BD_STASHING         0x00000200
 #define FSL_GIANFAR_DEV_HAS_BUF_STASHING        0x00000400
+#define FSL_GIANFAR_DEV_HAS_TIMER               0x00000800
 
 #if (MAXGROUPS == 2)
 #define DEFAULT_MAPPING         0xAA
@@ -1100,6 +1102,9 @@ struct gfar_private {
 
         /* Network Statistics */
         struct gfar_extra_stats extra_stats;
+
+        /* HW time stamping enabled flag */
+        int hwts_rx_en;
 };
 
 extern unsigned int ftp_rqfpr[MAX_FILER_IDX + 1];