netdev: bfin_mac: add support for IEEE 1588 PTP

Newer on-chip MAC peripherals support IEEE 1588 PTP in the hardware, so
extend the driver to support this functionality.

Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 340 insertions, 1 deletions

diff --git a/drivers/net/bfin_mac.c b/drivers/net/bfin_mac.c
index 35548701899f..a173d8a40484 100644
--- a/drivers/net/bfin_mac.c
+++ b/drivers/net/bfin_mac.c
@@ -33,6 +33,7 @@
 #include <asm/dma.h>
 #include <linux/dma-mapping.h>
 
+#include <asm/div64.h>
 #include <asm/dpmc.h>
 #include <asm/blackfin.h>
 #include <asm/cacheflush.h>
@@ -551,6 +552,309 @@ static int bfin_mac_set_mac_address(struct net_device *dev, void *p)
         return 0;
 }
 
+#ifdef CONFIG_BFIN_MAC_USE_HWSTAMP
+#define bfin_mac_hwtstamp_is_none(cfg) ((cfg) == HWTSTAMP_FILTER_NONE)
+
+static int bfin_mac_hwtstamp_ioctl(struct net_device *netdev,
+                struct ifreq *ifr, int cmd)
+{
+        struct hwtstamp_config config;
+        struct bfin_mac_local *lp = netdev_priv(netdev);
+        u16 ptpctl;
+        u32 ptpfv1, ptpfv2, ptpfv3, ptpfoff;
+
+        if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
+                return -EFAULT;
+
+        pr_debug("%s config flag:0x%x, tx_type:0x%x, rx_filter:0x%x\n",
+                        __func__, config.flags, config.tx_type, config.rx_filter);
+
+        /* reserved for future extensions */
+        if (config.flags)
+                return -EINVAL;
+
+        if ((config.tx_type != HWTSTAMP_TX_OFF) &&
+                        (config.tx_type != HWTSTAMP_TX_ON))
+                return -ERANGE;
+
+        ptpctl = bfin_read_EMAC_PTP_CTL();
+
+        switch (config.rx_filter) {
+        case HWTSTAMP_FILTER_NONE:
+                /*
+                 * Dont allow any timestamping
+                 */
+                ptpfv3 = 0xFFFFFFFF;
+                bfin_write_EMAC_PTP_FV3(ptpfv3);
+                break;
+        case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
+        case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
+        case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
+                /*
+                 * Clear the five comparison mask bits (bits[12:8]) in EMAC_PTP_CTL)
+                 * to enable all the field matches.
+                 */
+                ptpctl &= ~0x1F00;
+                bfin_write_EMAC_PTP_CTL(ptpctl);
+                /*
+                 * Keep the default values of the EMAC_PTP_FOFF register.
+                 */
+                ptpfoff = 0x4A24170C;
+                bfin_write_EMAC_PTP_FOFF(ptpfoff);
+                /*
+                 * Keep the default values of the EMAC_PTP_FV1 and EMAC_PTP_FV2
+                 * registers.
+                 */
+                ptpfv1 = 0x11040800;
+                bfin_write_EMAC_PTP_FV1(ptpfv1);
+                ptpfv2 = 0x0140013F;
+                bfin_write_EMAC_PTP_FV2(ptpfv2);
+                /*
+                 * The default value (0xFFFC) allows the timestamping of both
+                 * received Sync messages and Delay_Req messages.
+                 */
+                ptpfv3 = 0xFFFFFFFC;
+                bfin_write_EMAC_PTP_FV3(ptpfv3);
+
+                config.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_EVENT;
+                break;
+        case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
+        case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
+        case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
+                /* Clear all five comparison mask bits (bits[12:8]) in the
+                 * EMAC_PTP_CTL register to enable all the field matches.
+                 */
+                ptpctl &= ~0x1F00;
+                bfin_write_EMAC_PTP_CTL(ptpctl);
+                /*
+                 * Keep the default values of the EMAC_PTP_FOFF register, except set
+                 * the PTPCOF field to 0x2A.
+                 */
+                ptpfoff = 0x2A24170C;
+                bfin_write_EMAC_PTP_FOFF(ptpfoff);
+                /*
+                 * Keep the default values of the EMAC_PTP_FV1 and EMAC_PTP_FV2
+                 * registers.
+                 */
+                ptpfv1 = 0x11040800;
+                bfin_write_EMAC_PTP_FV1(ptpfv1);
+                ptpfv2 = 0x0140013F;
+                bfin_write_EMAC_PTP_FV2(ptpfv2);
+                /*
+                 * To allow the timestamping of Pdelay_Req and Pdelay_Resp, set
+                 * the value to 0xFFF0.
+                 */
+                ptpfv3 = 0xFFFFFFF0;
+                bfin_write_EMAC_PTP_FV3(ptpfv3);
+
+                config.rx_filter = HWTSTAMP_FILTER_PTP_V2_L4_EVENT;
+                break;
+        case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
+        case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
+        case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
+                /*
+                 * Clear bits 8 and 12 of the EMAC_PTP_CTL register to enable only the
+                 * EFTM and PTPCM field comparison.
+                 */
+                ptpctl &= ~0x1100;
+                bfin_write_EMAC_PTP_CTL(ptpctl);
+                /*
+                 * Keep the default values of all the fields of the EMAC_PTP_FOFF
+                 * register, except set the PTPCOF field to 0x0E.
+                 */
+                ptpfoff = 0x0E24170C;
+                bfin_write_EMAC_PTP_FOFF(ptpfoff);
+                /*
+                 * Program bits [15:0] of the EMAC_PTP_FV1 register to 0x88F7, which
+                 * corresponds to PTP messages on the MAC layer.
+                 */
+                ptpfv1 = 0x110488F7;
+                bfin_write_EMAC_PTP_FV1(ptpfv1);
+                ptpfv2 = 0x0140013F;
+                bfin_write_EMAC_PTP_FV2(ptpfv2);
+                /*
+                 * To allow the timestamping of Pdelay_Req and Pdelay_Resp
+                 * messages, set the value to 0xFFF0.
+                 */
+                ptpfv3 = 0xFFFFFFF0;
+                bfin_write_EMAC_PTP_FV3(ptpfv3);
+
+                config.rx_filter = HWTSTAMP_FILTER_PTP_V2_L2_EVENT;
+                break;
+        default:
+                return -ERANGE;
+        }
+
+        if (config.tx_type == HWTSTAMP_TX_OFF &&
+            bfin_mac_hwtstamp_is_none(config.rx_filter)) {
+                ptpctl &= ~PTP_EN;
+                bfin_write_EMAC_PTP_CTL(ptpctl);
+
+                SSYNC();
+        } else {
+                ptpctl |= PTP_EN;
+                bfin_write_EMAC_PTP_CTL(ptpctl);
+
+                /*
+                 * clear any existing timestamp
+                 */
+                bfin_read_EMAC_PTP_RXSNAPLO();
+                bfin_read_EMAC_PTP_RXSNAPHI();
+
+                bfin_read_EMAC_PTP_TXSNAPLO();
+                bfin_read_EMAC_PTP_TXSNAPHI();
+
+                /*
+                 * Set registers so that rollover occurs soon to test this.
+                 */
+                bfin_write_EMAC_PTP_TIMELO(0x00000000);
+                bfin_write_EMAC_PTP_TIMEHI(0xFF800000);
+
+                SSYNC();
+
+                lp->compare.last_update = 0;
+                timecounter_init(&lp->clock,
+                                &lp->cycles,
+                                ktime_to_ns(ktime_get_real()));
+                timecompare_update(&lp->compare, 0);
+        }
+
+        lp->stamp_cfg = config;
+        return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
+                -EFAULT : 0;
+}
+
+static void bfin_dump_hwtamp(char *s, ktime_t *hw, ktime_t *ts, struct timecompare *cmp)
+{
+        ktime_t sys = ktime_get_real();
+
+        pr_debug("%s %s hardware:%d,%d transform system:%d,%d system:%d,%d, cmp:%lld, %lld\n",
+                        __func__, s, hw->tv.sec, hw->tv.nsec, ts->tv.sec, ts->tv.nsec, sys.tv.sec,
+                        sys.tv.nsec, cmp->offset, cmp->skew);
+}
+
+static void bfin_tx_hwtstamp(struct net_device *netdev, struct sk_buff *skb)
+{
+        struct bfin_mac_local *lp = netdev_priv(netdev);
+        union skb_shared_tx *shtx = skb_tx(skb);
+
+        if (shtx->hardware) {
+                int timeout_cnt = MAX_TIMEOUT_CNT;
+
+                /* When doing time stamping, keep the connection to the socket
+                 * a while longer
+                 */
+                shtx->in_progress = 1;
+
+                /*
+                 * The timestamping is done at the EMAC module's MII/RMII interface
+                 * when the module sees the Start of Frame of an event message packet. This
+                 * interface is the closest possible place to the physical Ethernet transmission
+                 * medium, providing the best timing accuracy.
+                 */
+                while ((!(bfin_read_EMAC_PTP_ISTAT() & TXTL)) && (--timeout_cnt))
+                        udelay(1);
+                if (timeout_cnt == 0)
+                        printk(KERN_ERR DRV_NAME
+                                        ": fails to timestamp the TX packet\n");
+                else {
+                        struct skb_shared_hwtstamps shhwtstamps;
+                        u64 ns;
+                        u64 regval;
+
+                        regval = bfin_read_EMAC_PTP_TXSNAPLO();
+                        regval |= (u64)bfin_read_EMAC_PTP_TXSNAPHI() << 32;
+                        memset(&shhwtstamps, 0, sizeof(shhwtstamps));
+                        ns = timecounter_cyc2time(&lp->clock,
+                                        regval);
+                        timecompare_update(&lp->compare, ns);
+                        shhwtstamps.hwtstamp = ns_to_ktime(ns);
+                        shhwtstamps.syststamp =
+                                timecompare_transform(&lp->compare, ns);
+                        skb_tstamp_tx(skb, &shhwtstamps);
+
+                        bfin_dump_hwtamp("TX", &shhwtstamps.hwtstamp, &shhwtstamps.syststamp, &lp->compare);
+                }
+        }
+}
+
+static void bfin_rx_hwtstamp(struct net_device *netdev, struct sk_buff *skb)
+{
+        struct bfin_mac_local *lp = netdev_priv(netdev);
+        u32 valid;
+        u64 regval, ns;
+        struct skb_shared_hwtstamps *shhwtstamps;
+
+        if (bfin_mac_hwtstamp_is_none(lp->stamp_cfg.rx_filter))
+                return;
+
+        valid = bfin_read_EMAC_PTP_ISTAT() & RXEL;
+        if (!valid)
+                return;
+
+        shhwtstamps = skb_hwtstamps(skb);
+
+        regval = bfin_read_EMAC_PTP_RXSNAPLO();
+        regval |= (u64)bfin_read_EMAC_PTP_RXSNAPHI() << 32;
+        ns = timecounter_cyc2time(&lp->clock, regval);
+        timecompare_update(&lp->compare, ns);
+        memset(shhwtstamps, 0, sizeof(*shhwtstamps));
+        shhwtstamps->hwtstamp = ns_to_ktime(ns);
+        shhwtstamps->syststamp = timecompare_transform(&lp->compare, ns);
+
+        bfin_dump_hwtamp("RX", &shhwtstamps->hwtstamp, &shhwtstamps->syststamp, &lp->compare);
+}
+
+/*
+ * bfin_read_clock - read raw cycle counter (to be used by time counter)
+ */
+static cycle_t bfin_read_clock(const struct cyclecounter *tc)
+{
+        u64 stamp;
+
+        stamp =  bfin_read_EMAC_PTP_TIMELO();
+        stamp |= (u64)bfin_read_EMAC_PTP_TIMEHI() << 32ULL;
+
+        return stamp;
+}
+
+#define PTP_CLK 25000000
+
+static void bfin_mac_hwtstamp_init(struct net_device *netdev)
+{
+        struct bfin_mac_local *lp = netdev_priv(netdev);
+        u64 append;
+
+        /* Initialize hardware timer */
+        append = PTP_CLK * (1ULL << 32);
+        do_div(append, get_sclk());
+        bfin_write_EMAC_PTP_ADDEND((u32)append);
+
+        memset(&lp->cycles, 0, sizeof(lp->cycles));
+        lp->cycles.read = bfin_read_clock;
+        lp->cycles.mask = CLOCKSOURCE_MASK(64);
+        lp->cycles.mult = 1000000000 / PTP_CLK;
+        lp->cycles.shift = 0;
+
+        /* Synchronize our NIC clock against system wall clock */
+        memset(&lp->compare, 0, sizeof(lp->compare));
+        lp->compare.source = &lp->clock;
+        lp->compare.target = ktime_get_real;
+        lp->compare.num_samples = 10;
+
+        /* Initialize hwstamp config */
+        lp->stamp_cfg.rx_filter = HWTSTAMP_FILTER_NONE;
+        lp->stamp_cfg.tx_type = HWTSTAMP_TX_OFF;
+}
+
+#else
+# define bfin_mac_hwtstamp_is_none(cfg) 0
+# define bfin_mac_hwtstamp_init(dev)
+# define bfin_mac_hwtstamp_ioctl(dev, ifr, cmd) (-EOPNOTSUPP)
+# define bfin_rx_hwtstamp(dev, skb)
+# define bfin_tx_hwtstamp(dev, skb)
+#endif
+
 static void adjust_tx_list(void)
 {
         int timeout_cnt = MAX_TIMEOUT_CNT;
@@ -608,18 +912,32 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
 {
         u16 *data;
         u32 data_align = (unsigned long)(skb->data) & 0x3;
+        union skb_shared_tx *shtx = skb_tx(skb);
+
         current_tx_ptr->skb = skb;
 
         if (data_align == 0x2) {
                 /* move skb->data to current_tx_ptr payload */
                 data = (u16 *)(skb->data) - 1;
-                                *data = (u16)(skb->len);
+                *data = (u16)(skb->len);
+                /*
+                 * When transmitting an Ethernet packet, the PTP_TSYNC module requires
+                 * a DMA_Length_Word field associated with the packet. The lower 12 bits
+                 * of this field are the length of the packet payload in bytes and the higher
+                 * 4 bits are the timestamping enable field.
+                 */
+                if (shtx->hardware)
+                        *data |= 0x1000;
+
                 current_tx_ptr->desc_a.start_addr = (u32)data;
                 /* this is important! */
                 blackfin_dcache_flush_range((u32)data,
                                 (u32)((u8 *)data + skb->len + 4));
         } else {
                 *((u16 *)(current_tx_ptr->packet)) = (u16)(skb->len);
+                /* enable timestamping for the sent packet */
+                if (shtx->hardware)
+                        *((u16 *)(current_tx_ptr->packet)) |= 0x1000;
                 memcpy((u8 *)(current_tx_ptr->packet + 2), skb->data,
                         skb->len);
                 current_tx_ptr->desc_a.start_addr =
@@ -653,6 +971,9 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
 
 out:
         adjust_tx_list();
+
+        bfin_tx_hwtstamp(dev, skb);
+
         current_tx_ptr = current_tx_ptr->next;
         dev->stats.tx_packets++;
         dev->stats.tx_bytes += (skb->len);
@@ -663,9 +984,11 @@ static void bfin_mac_rx(struct net_device *dev)
 {
         struct sk_buff *skb, *new_skb;
         unsigned short len;
+        struct bfin_mac_local *lp __maybe_unused = netdev_priv(dev);
 
         /* allocate a new skb for next time receive */
         skb = current_rx_ptr->skb;
+
         new_skb = dev_alloc_skb(PKT_BUF_SZ + NET_IP_ALIGN);
         if (!new_skb) {
                 printk(KERN_NOTICE DRV_NAME
@@ -690,6 +1013,9 @@ static void bfin_mac_rx(struct net_device *dev)
                                          (unsigned long)skb->tail);
 
         skb->protocol = eth_type_trans(skb, dev);
+
+        bfin_rx_hwtstamp(dev, skb);
+
 #if defined(BFIN_MAC_CSUM_OFFLOAD)
         skb->csum = current_rx_ptr->status.ip_payload_csum;
         skb->ip_summed = CHECKSUM_COMPLETE;
@@ -871,6 +1197,16 @@ static void bfin_mac_set_multicast_list(struct net_device *dev)
         }
 }
 
+static int bfin_mac_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
+{
+        switch (cmd) {
+        case SIOCSHWTSTAMP:
+                return bfin_mac_hwtstamp_ioctl(netdev, ifr, cmd);
+        default:
+                return -EOPNOTSUPP;
+        }
+}
+
 /*
  * this puts the device in an inactive state
  */
@@ -955,6 +1291,7 @@ static const struct net_device_ops bfin_mac_netdev_ops = {
         .ndo_set_mac_address    = bfin_mac_set_mac_address,
         .ndo_tx_timeout         = bfin_mac_timeout,
         .ndo_set_multicast_list = bfin_mac_set_multicast_list,
+        .ndo_do_ioctl           = bfin_mac_ioctl,
         .ndo_validate_addr      = eth_validate_addr,
         .ndo_change_mtu         = eth_change_mtu,
 #ifdef CONFIG_NET_POLL_CONTROLLER
@@ -1046,6 +1383,8 @@ static int __devinit bfin_mac_probe(struct platform_device *pdev)
                 goto out_err_reg_ndev;
         }
 
+        bfin_mac_hwtstamp_init(ndev);
+
         /* now, print out the card info, in a short format.. */
         dev_info(&pdev->dev, "%s, Version %s\n", DRV_DESC, DRV_VERSION);