net: macb: Add hardware PTP support

This patch is based on original Harini's patch and Andrei's patch,
implemented in a separate file to ease the review/maintanance
and integration with other platforms.

This driver supports GEM-GXL:
- Register ptp clock framework
- Initialize PTP related registers
- HW time stamp on the PTP Ethernet packets are received using the
  SO_TIMESTAMPING API. Time stamps are obtained from the dma buffer
  descriptors
- add macb_ptp to compilation chain

Signed-off-by: Rafal Ozieblo <rafalo@cadence.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 84 insertions, 6 deletions

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 2d43a7619f58..41e5711544fc 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -847,6 +847,12 @@ static void macb_tx_interrupt(struct macb_queue *queue)
 
                         /* First, update TX stats if needed */
                         if (skb) {
+                                if (gem_ptp_do_txstamp(queue, skb, desc) == 0) {
+                                        /* skb now belongs to timestamp buffer
+                                         * and will be removed later
+                                         */
+                                        tx_skb->skb = NULL;
+                                }
                                 netdev_vdbg(bp->dev, "skb %u (data %p) TX complete\n",
                                             macb_tx_ring_wrap(bp, tail),
                                             skb->data);
@@ -1013,6 +1019,8 @@ static int gem_rx(struct macb *bp, int budget)
                 bp->dev->stats.rx_packets++;
                 bp->dev->stats.rx_bytes += skb->len;
 
+                gem_ptp_do_rxstamp(bp, skb, desc);
+
 #if defined(DEBUG) && defined(VERBOSE_DEBUG)
                 netdev_vdbg(bp->dev, "received skb of length %u, csum: %08x\n",
                             skb->len, skb->csum);
@@ -1334,7 +1342,6 @@ static irqreturn_t macb_interrupt(int irq, void *dev_id)
                         if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
                                 queue_writel(queue, ISR, MACB_BIT(HRESP));
                 }
-
                 status = queue_readl(queue, ISR);
         }
 
@@ -1664,7 +1671,6 @@ static int macb_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
         /* Make newly initialized descriptor visible to hardware */
         wmb();
-
         skb_tx_timestamp(skb);
 
         macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(TSTART));
@@ -2522,6 +2528,70 @@ static int macb_set_ringparam(struct net_device *netdev,
         return 0;
 }
 
+#ifdef CONFIG_MACB_USE_HWSTAMP
+static unsigned int gem_get_tsu_rate(struct macb *bp)
+{
+        struct clk *tsu_clk;
+        unsigned int tsu_rate;
+
+        tsu_clk = devm_clk_get(&bp->pdev->dev, "tsu_clk");
+        if (!IS_ERR(tsu_clk))
+                tsu_rate = clk_get_rate(tsu_clk);
+        /* try pclk instead */
+        else if (!IS_ERR(bp->pclk)) {
+                tsu_clk = bp->pclk;
+                tsu_rate = clk_get_rate(tsu_clk);
+        } else
+                return -ENOTSUPP;
+        return tsu_rate;
+}
+
+static s32 gem_get_ptp_max_adj(void)
+{
+        return 64000000;
+}
+
+static int gem_get_ts_info(struct net_device *dev,
+                           struct ethtool_ts_info *info)
+{
+        struct macb *bp = netdev_priv(dev);
+
+        if ((bp->hw_dma_cap & HW_DMA_CAP_PTP) == 0) {
+                ethtool_op_get_ts_info(dev, info);
+                return 0;
+        }
+
+        info->so_timestamping =
+                SOF_TIMESTAMPING_TX_SOFTWARE |
+                SOF_TIMESTAMPING_RX_SOFTWARE |
+                SOF_TIMESTAMPING_SOFTWARE |
+                SOF_TIMESTAMPING_TX_HARDWARE |
+                SOF_TIMESTAMPING_RX_HARDWARE |
+                SOF_TIMESTAMPING_RAW_HARDWARE;
+        info->tx_types =
+                (1 << HWTSTAMP_TX_ONESTEP_SYNC) |
+                (1 << HWTSTAMP_TX_OFF) |
+                (1 << HWTSTAMP_TX_ON);
+        info->rx_filters =
+                (1 << HWTSTAMP_FILTER_NONE) |
+                (1 << HWTSTAMP_FILTER_ALL);
+
+        info->phc_index = bp->ptp_clock ? ptp_clock_index(bp->ptp_clock) : -1;
+
+        return 0;
+}
+
+static struct macb_ptp_info gem_ptp_info = {
+        .ptp_init        = gem_ptp_init,
+        .ptp_remove      = gem_ptp_remove,
+        .get_ptp_max_adj = gem_get_ptp_max_adj,
+        .get_tsu_rate    = gem_get_tsu_rate,
+        .get_ts_info     = gem_get_ts_info,
+        .get_hwtst       = gem_get_hwtst,
+        .set_hwtst       = gem_set_hwtst,
+};
+#endif
+
 static int macb_get_ts_info(struct net_device *netdev,
                             struct ethtool_ts_info *info)
 {
@@ -2655,12 +2725,16 @@ static void macb_configure_caps(struct macb *bp,
                 dcfg = gem_readl(bp, DCFG2);
                 if ((dcfg & (GEM_BIT(RX_PKT_BUFF) | GEM_BIT(TX_PKT_BUFF))) == 0)
                         bp->caps |= MACB_CAPS_FIFO_MODE;
-                if (IS_ENABLED(CONFIG_MACB_USE_HWSTAMP) && gem_has_ptp(bp)) {
+#ifdef CONFIG_MACB_USE_HWSTAMP
+                if (gem_has_ptp(bp)) {
                         if (!GEM_BFEXT(TSU, gem_readl(bp, DCFG5)))
                                 pr_err("GEM doesn't support hardware ptp.\n");
-                        else
+                        else {
                                 bp->hw_dma_cap |= HW_DMA_CAP_PTP;
+                                bp->ptp_info = &gem_ptp_info;
+                        }
                 }
+#endif
         }
 
         dev_dbg(&bp->pdev->dev, "Cadence caps 0x%08x\n", bp->caps);
@@ -3266,7 +3340,9 @@ static const struct macb_config np4_config = {
 };
 
 static const struct macb_config zynqmp_config = {
-        .caps = MACB_CAPS_GIGABIT_MODE_AVAILABLE | MACB_CAPS_JUMBO,
+        .caps = MACB_CAPS_GIGABIT_MODE_AVAILABLE |
+                        MACB_CAPS_JUMBO |
+                        MACB_CAPS_GEM_HAS_PTP,
         .dma_burst_length = 16,
         .clk_init = macb_clk_init,
         .init = macb_init,
@@ -3300,7 +3376,9 @@ MODULE_DEVICE_TABLE(of, macb_dt_ids);
 #endif /* CONFIG_OF */
 
 static const struct macb_config default_gem_config = {
-        .caps = MACB_CAPS_GIGABIT_MODE_AVAILABLE | MACB_CAPS_JUMBO,
+        .caps = MACB_CAPS_GIGABIT_MODE_AVAILABLE |
+                        MACB_CAPS_JUMBO |
+                        MACB_CAPS_GEM_HAS_PTP,
         .dma_burst_length = 16,
         .clk_init = macb_clk_init,
         .init = macb_init,