Renesas Ethernet AVB PTP clock driver

Ethernet AVB device includes the gPTP  timer, so we can implement a PTP clock
driver.  We're doing that in a separate file, with  the main Ethernet driver
calling the PTP driver's [de]initialization and interrupt handler functions.
Unfortunately, the clock seems tightly coupled with the AVB-DMAC, so when that
one leaves the operation mode, we have to unregister the PTP clock... :-(

Based on the original patches by Masaru Nagai.

Signed-off-by: Masaru Nagai <[email protected]>
Signed-off-by: Sergei Shtylyov <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Sergei Shtylyov

drivers/net/ethernet/renesas/Makefile

@@ -3,4 +3,7 @@
 #
 
 obj-$(CONFIG_SH_ETH) += sh_eth.o
+
+ravb-objs := ravb_main.o ravb_ptp.o
+
 obj-$(CONFIG_RAVB) += ravb.o

drivers/net/ethernet/renesas/ravb.h

@@ -20,6 +20,8 @@
 #include <linux/mdio-bitbang.h>
 #include <linux/netdevice.h>
 #include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/ptp_clock_kernel.h>
 
 #define BE_TX_RING_SIZE	64	/* TX ring size for Best Effort */
 #define BE_RX_RING_SIZE	1024	/* RX ring size for Best Effort */
@@ -744,6 +746,23 @@ struct ravb_tstamp_skb {
 	u16 tag;
 };
 
+struct ravb_ptp_perout {
+	u32 target;
+	u32 period;
+};
+
+#define N_EXT_TS	1
+#define N_PER_OUT	1
+
+struct ravb_ptp {
+	struct ptp_clock *clock;
+	struct ptp_clock_info info;
+	u32 default_addend;
+	u32 current_addend;
+	int extts[N_EXT_TS];
+	struct ravb_ptp_perout perout[N_PER_OUT];
+};
+
 struct ravb_private {
 	struct net_device *ndev;
 	struct platform_device *pdev;
@@ -768,6 +787,7 @@ struct ravb_private {
 	u32 tstamp_rx_ctrl;
 	struct list_head ts_skb_list;
 	u32 ts_skb_tag;
+	struct ravb_ptp ptp;
 	spinlock_t lock;		/* Register access lock */
 	u32 cur_rx[NUM_RX_QUEUE];	/* Consumer ring indices */
 	u32 dirty_rx[NUM_RX_QUEUE];	/* Producer ring indices */
@@ -803,4 +823,10 @@ static inline void ravb_write(struct net_device *ndev, u32 data,
 	iowrite32(data, priv->addr + reg);
 }
 
+int ravb_wait(struct net_device *ndev, enum ravb_reg reg, u32 mask, u32 value);
+
+irqreturn_t ravb_ptp_interrupt(struct net_device *ndev);
+void ravb_ptp_init(struct net_device *ndev, struct platform_device *pdev);
+void ravb_ptp_stop(struct net_device *ndev);
+
 #endif	/* #ifndef __RAVB_H__ */

drivers/net/ethernet/renesas/ravb.c renamed to drivers/net/ethernet/renesas/ravb_main.c

@@ -28,7 +28,6 @@
 #include <linux/of_irq.h>
 #include <linux/of_mdio.h>
 #include <linux/of_net.h>
-#include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
@@ -41,8 +40,7 @@
 		 NETIF_MSG_RX_ERR | \
 		 NETIF_MSG_TX_ERR)
 
-static int ravb_wait(struct net_device *ndev, enum ravb_reg reg, u32 mask,
-		     u32 value)
+int ravb_wait(struct net_device *ndev, enum ravb_reg reg, u32 mask, u32 value)
 {
 	int i;
 
@@ -763,6 +761,9 @@ static irqreturn_t ravb_interrupt(int irq, void *dev_id)
 		result = IRQ_HANDLED;
 	}
 
+	if (iss & ISS_CGIS)
+		result = ravb_ptp_interrupt(ndev);
+
 	mmiowb();
 	spin_unlock(&priv->lock);
 	return result;
@@ -1103,6 +1104,8 @@ static int ravb_set_ringparam(struct net_device *ndev,
 
 	if (netif_running(ndev)) {
 		netif_device_detach(ndev);
+		/* Stop PTP Clock driver */
+		ravb_ptp_stop(ndev);
 		/* Wait for DMA stopping */
 		error = ravb_stop_dma(ndev);
 		if (error) {
@@ -1132,6 +1135,9 @@ static int ravb_set_ringparam(struct net_device *ndev,
 
 		ravb_emac_init(ndev);
 
+		/* Initialise PTP Clock driver */
+		ravb_ptp_init(ndev, priv->pdev);
+
 		netif_device_attach(ndev);
 	}
 
@@ -1141,6 +1147,8 @@ static int ravb_set_ringparam(struct net_device *ndev,
 static int ravb_get_ts_info(struct net_device *ndev,
 			    struct ethtool_ts_info *info)
 {
+	struct ravb_private *priv = netdev_priv(ndev);
+
 	info->so_timestamping =
 		SOF_TIMESTAMPING_TX_SOFTWARE |
 		SOF_TIMESTAMPING_RX_SOFTWARE |
@@ -1153,7 +1161,7 @@ static int ravb_get_ts_info(struct net_device *ndev,
 		(1 << HWTSTAMP_FILTER_NONE) |
 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
 		(1 << HWTSTAMP_FILTER_ALL);
-	info->phc_index = -1;
+	info->phc_index = ptp_clock_index(priv->ptp.clock);
 
 	return 0;
 }
@@ -1195,15 +1203,21 @@ static int ravb_open(struct net_device *ndev)
 		goto out_free_irq;
 	ravb_emac_init(ndev);
 
+	/* Initialise PTP Clock driver */
+	ravb_ptp_init(ndev, priv->pdev);
+
 	netif_tx_start_all_queues(ndev);
 
 	/* PHY control start */
 	error = ravb_phy_start(ndev);
 	if (error)
-		goto out_free_irq;
+		goto out_ptp_stop;
 
 	return 0;
 
+out_ptp_stop:
+	/* Stop PTP Clock driver */
+	ravb_ptp_stop(ndev);
 out_free_irq:
 	free_irq(ndev->irq, ndev);
 out_napi_off:
@@ -1235,6 +1249,9 @@ static void ravb_tx_timeout_work(struct work_struct *work)
 
 	netif_tx_stop_all_queues(ndev);
 
+	/* Stop PTP Clock driver */
+	ravb_ptp_stop(ndev);
+
 	/* Wait for DMA stopping */
 	ravb_stop_dma(ndev);
 
@@ -1245,6 +1262,9 @@ static void ravb_tx_timeout_work(struct work_struct *work)
 	ravb_dmac_init(ndev);
 	ravb_emac_init(ndev);
 
+	/* Initialise PTP Clock driver */
+	ravb_ptp_init(ndev, priv->pdev);
+
 	netif_tx_start_all_queues(ndev);
 }
 
@@ -1409,6 +1429,9 @@ static int ravb_close(struct net_device *ndev)
 	ravb_write(ndev, 0, RIC2);
 	ravb_write(ndev, 0, TIC);
 
+	/* Stop PTP Clock driver */
+	ravb_ptp_stop(ndev);
+
 	/* Set the config mode to stop the AVB-DMAC's processes */
 	if (ravb_stop_dma(ndev) < 0)
 		netdev_err(ndev,