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@xxxxxx>
---
drivers/net/can/c_can/c_can.c | 82 ++++++++++++++++++++++++++++++++
drivers/net/can/c_can/c_can.h | 8 ++++
drivers/net/can/c_can/c_can_platform.c | 62 ++++++++++++++++++++++++
3 files changed, 152 insertions(+)
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index c175410..c601136 100644
--- 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
@@ -1154,6 +1161,81 @@ 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;
+
+ BUG_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);
+
+ /* De-initialize DCAN RAM */
+ c_can_reset_ram(priv, false);
+ 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;
+
+ BUG_ON(priv->type != BOSCH_D_CAN);
+
+ c_can_pm_runtime_get_sync(priv);
+ /* Initialize DCAN RAM */
+ c_can_reset_ram(priv, true);
+
+ /* 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 5f6339c..ca149eb 100644
--- 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;
unsigned int instance;
void (*ram_init) (unsigned int instance, bool enable);
};
@@ -175,4 +178,9 @@ 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 c6963b2..68c186b 100644
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c
@@ -202,6 +202,7 @@ 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);
@@ -255,6 +256,65 @@ 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,
@@ -263,6 +323,8 @@ 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,
};
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
