[PATCH 3/8] netdev: octeon_mgmt: Add hardware timestamp support.

[David Daney]

From: Chad Reese <kreese@xxxxxxxxxxxxxxxxxx>

Octeon cn6XXX models have timestamp support on the mgmt ports, so hook
it up.

Signed-off-by: Chad Reese <kreese@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
---
 drivers/net/ethernet/octeon/octeon_mgmt.c | 157 +++++++++++++++++++++++++++++-
 1 file changed, 152 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/octeon/octeon_mgmt.c b/drivers/net/ethernet/octeon/octeon_mgmt.c
index c4df1ab..687a6a0 100644
--- a/drivers/net/ethernet/octeon/octeon_mgmt.c
+++ b/drivers/net/ethernet/octeon/octeon_mgmt.c
@@ -10,6 +10,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/etherdevice.h>
 #include <linux/capability.h>
+#include <linux/net_tstamp.h>
 #include <linux/interrupt.h>
 #include <linux/netdevice.h>
 #include <linux/spinlock.h>
@@ -114,6 +115,7 @@ struct octeon_mgmt {
 	u64 agl_prt_ctl;
 	int port;
 	int irq;
+	bool has_rx_tstamp;
 	u64 *tx_ring;
 	dma_addr_t tx_ring_handle;
 	unsigned int tx_next;
@@ -238,6 +240,28 @@ static void octeon_mgmt_rx_fill_ring(struct net_device *netdev)
 	}
 }
 
+static ktime_t ptp_to_ktime(u64 ptptime)
+{
+	ktime_t ktimebase;
+	u64 ptpbase;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	/* Fill the icache with the code */
+	ktime_get_real();
+	/* Flush all pending operations */
+	mb();
+	/* Read the time and PTP clock as close together as
+	 * possible. It is important that this sequence take the same
+	 * amount of time to reduce jitter
+	 */
+	ktimebase = ktime_get_real();
+	ptpbase = cvmx_read_csr(CVMX_MIO_PTP_CLOCK_HI);
+	local_irq_restore(flags);
+
+	return ktime_sub_ns(ktimebase, ptpbase - ptptime);
+}
+
 static void octeon_mgmt_clean_tx_buffers(struct octeon_mgmt *p)
 {
 	union cvmx_mixx_orcnt mix_orcnt;
@@ -277,6 +301,20 @@ static void octeon_mgmt_clean_tx_buffers(struct octeon_mgmt *p)
 
 		dma_unmap_single(p->dev, re.s.addr, re.s.len,
 				 DMA_TO_DEVICE);
+
+		/* Read the hardware TX timestamp if one was recorded */
+		if (unlikely(re.s.tstamp)) {
+			struct skb_shared_hwtstamps ts;
+			/* Read the timestamp */
+			u64 ns = cvmx_read_csr(CVMX_MIXX_TSTAMP(p->port));
+			/* Remove the timestamp from the FIFO */
+			cvmx_write_csr(CVMX_MIXX_TSCTL(p->port), 0);
+			/* Tell the kernel about the timestamp */
+			ts.syststamp = ptp_to_ktime(ns);
+			ts.hwtstamp = ns_to_ktime(ns);
+			skb_tstamp_tx(skb, &ts);
+		}
+
 		dev_kfree_skb_any(skb);
 		cleaned++;
 
@@ -377,6 +415,16 @@ static int octeon_mgmt_receive_one(struct octeon_mgmt *p)
 		/* A good packet, send it up. */
 		skb_put(skb, re.s.len);
 good:
+		/* Process the RX timestamp if it was recorded */
+		if (p->has_rx_tstamp) {
+			/* The first 8 bytes are the timestamp */
+			u64 ns = *(u64 *)skb->data;
+			struct skb_shared_hwtstamps *ts;
+			ts = skb_hwtstamps(skb);
+			ts->hwtstamp = ns_to_ktime(ns);
+			ts->syststamp = ptp_to_ktime(ns);
+			__skb_pull(skb, 8);
+		}
 		skb->protocol = eth_type_trans(skb, netdev);
 		netdev->stats.rx_packets++;
 		netdev->stats.rx_bytes += skb->len;
@@ -661,18 +709,114 @@ static irqreturn_t octeon_mgmt_interrupt(int cpl, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static int octeon_mgmt_ioctl(struct net_device *netdev,
-			     struct ifreq *rq, int cmd)
+static int octeon_mgmt_ioctl_hwtstamp(struct net_device *netdev,
+				      struct ifreq *rq, int cmd)
 {
 	struct octeon_mgmt *p = netdev_priv(netdev);
+	struct hwtstamp_config config;
+	union cvmx_mio_ptp_clock_cfg ptp;
+	union cvmx_agl_gmx_rxx_frm_ctl rxx_frm_ctl;
+	bool have_hw_timestamps = false;
+
+	if (copy_from_user(&config, rq->ifr_data, sizeof(config)))
+		return -EFAULT;
 
-	if (!netif_running(netdev))
+	if (config.flags) /* reserved for future extensions */
 		return -EINVAL;
 
-	if (!p->phydev)
+	/* Check the status of hardware for tiemstamps */
+	if (OCTEON_IS_MODEL(OCTEON_CN6XXX)) {
+		/* Get the current state of the PTP clock */
+		ptp.u64 = cvmx_read_csr(CVMX_MIO_PTP_CLOCK_CFG);
+		if (!ptp.s.ext_clk_en) {
+			/* The clock has not been configured to use an
+			 * external source.  Program it to use the main clock
+			 * reference.
+			 */
+			u64 clock_comp = (NSEC_PER_SEC << 32) /	octeon_get_io_clock_rate();
+			if (!ptp.s.ptp_en)
+				cvmx_write_csr(CVMX_MIO_PTP_CLOCK_COMP, clock_comp);
+			pr_info("PTP Clock: Using sclk reference at %lld Hz\n",
+				(NSEC_PER_SEC << 32) / clock_comp);
+		} else {
+			/* The clock is already programmed to use a GPIO */
+			u64 clock_comp = cvmx_read_csr(CVMX_MIO_PTP_CLOCK_COMP);
+			pr_info("PTP Clock: Using GPIO %d at %lld Hz\n",
+				ptp.s.ext_clk_in,
+				(NSEC_PER_SEC << 32) / clock_comp);
+		}
+
+		/* Enable the clock if it wasn't done already */
+		if (!ptp.s.ptp_en) {
+			ptp.s.ptp_en = 1;
+			cvmx_write_csr(CVMX_MIO_PTP_CLOCK_CFG, ptp.u64);
+		}
+		have_hw_timestamps = true;
+	}
+
+	if (!have_hw_timestamps)
 		return -EINVAL;
 
-	return phy_mii_ioctl(p->phydev, rq, cmd);
+	switch (config.tx_type) {
+	case HWTSTAMP_TX_OFF:
+	case HWTSTAMP_TX_ON:
+		break;
+	default:
+		return -ERANGE;
+	}
+
+	switch (config.rx_filter) {
+	case HWTSTAMP_FILTER_NONE:
+		p->has_rx_tstamp = false;
+		rxx_frm_ctl.u64 = cvmx_read_csr(p->agl + AGL_GMX_RX_FRM_CTL);
+		rxx_frm_ctl.s.ptp_mode = 0;
+		cvmx_write_csr(p->agl + AGL_GMX_RX_FRM_CTL, rxx_frm_ctl.u64);
+		break;
+	case HWTSTAMP_FILTER_ALL:
+	case HWTSTAMP_FILTER_SOME:
+	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
+	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
+	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
+	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
+	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
+	case HWTSTAMP_FILTER_PTP_V2_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
+		p->has_rx_tstamp = have_hw_timestamps;
+		config.rx_filter = HWTSTAMP_FILTER_ALL;
+		if (p->has_rx_tstamp) {
+			rxx_frm_ctl.u64 = cvmx_read_csr(p->agl + AGL_GMX_RX_FRM_CTL);
+			rxx_frm_ctl.s.ptp_mode = 1;
+			cvmx_write_csr(p->agl + AGL_GMX_RX_FRM_CTL, rxx_frm_ctl.u64);
+		}
+		break;
+	default:
+		return -ERANGE;
+	}
+
+	if (copy_to_user(rq->ifr_data, &config, sizeof(config)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int octeon_mgmt_ioctl(struct net_device *netdev,
+			     struct ifreq *rq, int cmd)
+{
+	struct octeon_mgmt *p = netdev_priv(netdev);
+
+	switch (cmd) {
+	case SIOCSHWTSTAMP:
+		return octeon_mgmt_ioctl_hwtstamp(netdev, rq, cmd);
+	default:
+		if (p->phydev)
+			return phy_mii_ioctl(p->phydev, rq, cmd);
+		return -EINVAL;
+	}
 }
 
 static void octeon_mgmt_disable_link(struct octeon_mgmt *p)
@@ -1052,6 +1196,7 @@ static int octeon_mgmt_open(struct net_device *netdev)
 	/* Enable packet I/O. */
 
 	rxx_frm_ctl.u64 = 0;
+	rxx_frm_ctl.s.ptp_mode = p->has_rx_tstamp ? 1 : 0;
 	rxx_frm_ctl.s.pre_align = 1;
 	/*
 	 * When set, disables the length check for non-min sized pkts
@@ -1155,6 +1300,7 @@ static int octeon_mgmt_xmit(struct sk_buff *skb, struct net_device *netdev)
 	int rv = NETDEV_TX_BUSY;
 
 	re.d64 = 0;
+	re.s.tstamp = ((skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) != 0);
 	re.s.len = skb->len;
 	re.s.addr = dma_map_single(p->dev, skb->data,
 				   skb->len,
@@ -1293,6 +1439,7 @@ static int __devinit octeon_mgmt_probe(struct platform_device *pdev)
 
 	p->netdev = netdev;
 	p->dev = &pdev->dev;
+	p->has_rx_tstamp = false;
 
 	data = of_get_property(pdev->dev.of_node, "cell-index", &len);
 	if (data && len == sizeof(*data)) {
-- 
1.7.11.4

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