can: c_can: Add d_can suspend resume support

Adds suspend resume support to DCAN driver which enables
DCAN power down mode bit (PDR). Then DCAN will ack the local
power-down mode by setting PDA bit in STATUS register.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 768bb48..2c4a21f 100644 (file)
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -46,6 +46,9 @@
 #define IF_ENUM_REG_LEN                11
 #define C_CAN_IFACE(reg, iface)        (C_CAN_IF1_##reg + (iface) * IF_ENUM_REG_LEN)
 
+/* control extension register D_CAN specific */
+#define CONTROL_EX_PDR         BIT(8)
+
 /* control register */
 #define CONTROL_TEST           BIT(7)
 #define CONTROL_CCE            BIT(6)
@@ -65,6 +68,7 @@
 #define TEST_BASIC             BIT(2)
 
 /* status register */
+#define STATUS_PDA             BIT(10)
 #define STATUS_BOFF            BIT(7)
 #define STATUS_EWARN           BIT(6)
 #define STATUS_EPASS           BIT(5)
@@ -164,6 +168,9 @@
 /* minimum timeout for checking BUSY status */
 #define MIN_TIMEOUT_VALUE      6
 
+/* Wait for ~1 sec for INIT bit */
+#define INIT_WAIT_MS           1000
+
 /* napi related */
 #define C_CAN_NAPI_WEIGHT      C_CAN_MSG_OBJ_RX_NUM
 
@@ -1153,6 +1160,77 @@ struct net_device *alloc_c_can_dev(void)
 }
 EXPORT_SYMBOL_GPL(alloc_c_can_dev);
 
+#ifdef CONFIG_PM
+int c_can_power_down(struct net_device *dev)
+{
+       u32 val;
+       unsigned long time_out;
+       struct c_can_priv *priv = netdev_priv(dev);
+
+       if (!(dev->flags & IFF_UP))
+               return 0;
+
+       WARN_ON(priv->type != BOSCH_D_CAN);
+
+       /* set PDR value so the device goes to power down mode */
+       val = priv->read_reg(priv, C_CAN_CTRL_EX_REG);
+       val |= CONTROL_EX_PDR;
+       priv->write_reg(priv, C_CAN_CTRL_EX_REG, val);
+
+       /* Wait for the PDA bit to get set */
+       time_out = jiffies + msecs_to_jiffies(INIT_WAIT_MS);
+       while (!(priv->read_reg(priv, C_CAN_STS_REG) & STATUS_PDA) &&
+                               time_after(time_out, jiffies))
+               cpu_relax();
+
+       if (time_after(jiffies, time_out))
+               return -ETIMEDOUT;
+
+       c_can_stop(dev);
+
+       c_can_pm_runtime_put_sync(priv);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(c_can_power_down);
+
+int c_can_power_up(struct net_device *dev)
+{
+       u32 val;
+       unsigned long time_out;
+       struct c_can_priv *priv = netdev_priv(dev);
+
+       if (!(dev->flags & IFF_UP))
+               return 0;
+
+       WARN_ON(priv->type != BOSCH_D_CAN);
+
+       c_can_pm_runtime_get_sync(priv);
+
+       /* Clear PDR and INIT bits */
+       val = priv->read_reg(priv, C_CAN_CTRL_EX_REG);
+       val &= ~CONTROL_EX_PDR;
+       priv->write_reg(priv, C_CAN_CTRL_EX_REG, val);
+       val = priv->read_reg(priv, C_CAN_CTRL_REG);
+       val &= ~CONTROL_INIT;
+       priv->write_reg(priv, C_CAN_CTRL_REG, val);
+
+       /* Wait for the PDA bit to get clear */
+       time_out = jiffies + msecs_to_jiffies(INIT_WAIT_MS);
+       while ((priv->read_reg(priv, C_CAN_STS_REG) & STATUS_PDA) &&
+                               time_after(time_out, jiffies))
+               cpu_relax();
+
+       if (time_after(jiffies, time_out))
+               return -ETIMEDOUT;
+
+       c_can_start(dev);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(c_can_power_up);
+#endif
+
 void free_c_can_dev(struct net_device *dev)
 {
        free_candev(dev);

diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index 1437a6d..e5ed41d 100644 (file)
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -24,6 +24,7 @@
 
 enum reg {
        C_CAN_CTRL_REG = 0,
+       C_CAN_CTRL_EX_REG,
        C_CAN_STS_REG,
        C_CAN_ERR_CNT_REG,
        C_CAN_BTR_REG,
@@ -104,6 +105,7 @@ static const u16 reg_map_c_can[] = {
 
 static const u16 reg_map_d_can[] = {
        [C_CAN_CTRL_REG]        = 0x00,
+       [C_CAN_CTRL_EX_REG]     = 0x02,
        [C_CAN_STS_REG]         = 0x04,
        [C_CAN_ERR_CNT_REG]     = 0x08,
        [C_CAN_BTR_REG]         = 0x0C,
@@ -166,6 +168,7 @@ struct c_can_priv {
        unsigned int tx_echo;
        void *priv;             /* for board-specific data */
        u16 irqstatus;
+       enum c_can_dev_id type;
 };
 
 struct net_device *alloc_c_can_dev(void);
@@ -173,4 +176,9 @@ void free_c_can_dev(struct net_device *dev);
 int register_c_can_dev(struct net_device *dev);
 void unregister_c_can_dev(struct net_device *dev);
 
+#ifdef CONFIG_PM
+int c_can_power_up(struct net_device *dev);
+int c_can_power_down(struct net_device *dev);
+#endif
+
 #endif /* C_CAN_H */

diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
index 7b8b7a4..8a4e9d8 100644 (file)
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c
@@ -182,6 +182,7 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev)
        priv->device = &pdev->dev;
        priv->can.clock.freq = clk_get_rate(clk);
        priv->priv = clk;
+       priv->type = id->driver_data;
 
        platform_set_drvdata(pdev, dev);
        SET_NETDEV_DEV(dev, &pdev->dev);
@@ -232,6 +233,65 @@ static int __devexit c_can_plat_remove(struct platform_device *pdev)
        return 0;
 }
 
+#ifdef CONFIG_PM
+static int c_can_suspend(struct platform_device *pdev, pm_message_t state)
+{
+       int ret;
+       struct net_device *ndev = platform_get_drvdata(pdev);
+       struct c_can_priv *priv = netdev_priv(ndev);
+
+       if (priv->type != BOSCH_D_CAN) {
+               dev_warn(&pdev->dev, "Not supported\n");
+               return 0;
+       }
+
+       if (netif_running(ndev)) {
+               netif_stop_queue(ndev);
+               netif_device_detach(ndev);
+       }
+
+       ret = c_can_power_down(ndev);
+       if (ret) {
+               netdev_err(ndev, "failed to enter power down mode\n");
+               return ret;
+       }
+
+       priv->can.state = CAN_STATE_SLEEPING;
+
+       return 0;
+}
+
+static int c_can_resume(struct platform_device *pdev)
+{
+       int ret;
+       struct net_device *ndev = platform_get_drvdata(pdev);
+       struct c_can_priv *priv = netdev_priv(ndev);
+
+       if (priv->type != BOSCH_D_CAN) {
+               dev_warn(&pdev->dev, "Not supported\n");
+               return 0;
+       }
+
+       ret = c_can_power_up(ndev);
+       if (ret) {
+               netdev_err(ndev, "Still in power down mode\n");
+               return ret;
+       }
+
+       priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+       if (netif_running(ndev)) {
+               netif_device_attach(ndev);
+               netif_start_queue(ndev);
+       }
+
+       return 0;
+}
+#else
+#define c_can_suspend NULL
+#define c_can_resume NULL
+#endif
+
 static struct platform_driver c_can_plat_driver = {
        .driver = {
                .name = KBUILD_MODNAME,
@@ -240,6 +300,8 @@ static struct platform_driver c_can_plat_driver = {
        },
        .probe = c_can_plat_probe,
        .remove = __devexit_p(c_can_plat_remove),
+       .suspend = c_can_suspend,
+       .resume = c_can_resume,
        .id_table = c_can_id_table,
 };