[PATCH 4/4] can: c_can: Add d_can suspend resume support
AnilKumar Ch
anilkumar at ti.com
Mon Sep 3 07:52:19 EDT 2012
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.
Also adds a status flag to know the status of DCAN module,
whether it is opened or not.
Signed-off-by: AnilKumar Ch <anilkumar at ti.com>
---
drivers/net/can/c_can/c_can.c | 78 ++++++++++++++++++++++++++++++++
drivers/net/can/c_can/c_can.h | 5 ++
drivers/net/can/c_can/c_can_platform.c | 70 ++++++++++++++++++++++++++--
3 files changed, 150 insertions(+), 3 deletions(-)
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index c175410..36d5db4 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_COUNT 1000
+
/* napi related */
#define C_CAN_NAPI_WEIGHT C_CAN_MSG_OBJ_RX_NUM
@@ -1102,6 +1109,7 @@ static int c_can_open(struct net_device *dev)
netif_start_queue(dev);
+ priv->is_opened = true;
return 0;
exit_irq_fail:
@@ -1126,6 +1134,7 @@ static int c_can_close(struct net_device *dev)
/* De-Initialize DCAN RAM */
c_can_reset_ram(priv, false);
c_can_pm_runtime_put_sync(priv);
+ priv->is_opened = false;
return 0;
}
@@ -1154,6 +1163,75 @@ 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)
+{
+ unsigned long time_out;
+ struct c_can_priv *priv = netdev_priv(dev);
+
+ if (!priv->is_opened)
+ return 0;
+
+ /* set `PDR` value so the device goes to power down mode */
+ priv->write_reg(priv, C_CAN_CTRL_EX_REG,
+ priv->read_reg(priv, C_CAN_CTRL_EX_REG) | CONTROL_EX_PDR);
+
+ /* Wait for the PDA bit to get set */
+ time_out = jiffies + msecs_to_jiffies(INIT_WAIT_COUNT);
+ 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)
+{
+ unsigned long time_out;
+ struct c_can_priv *priv = netdev_priv(dev);
+
+ if (!priv->is_opened)
+ return 0;
+
+ c_can_pm_runtime_get_sync(priv);
+ /* Initialize DCAN RAM */
+ c_can_reset_ram(priv, true);
+
+ /* Clear PDR and INIT bits */
+ priv->write_reg(priv, C_CAN_CTRL_EX_REG,
+ priv->read_reg(priv, C_CAN_CTRL_EX_REG) & ~CONTROL_EX_PDR);
+ priv->write_reg(priv, C_CAN_CTRL_REG,
+ priv->read_reg(priv, C_CAN_CTRL_REG) & ~CONTROL_INIT);
+
+ /* Wait for the PDA bit to get clear */
+ time_out = jiffies + msecs_to_jiffies(INIT_WAIT_COUNT);
+ 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);
+#else
+#define c_can_power_down NULL
+#define c_can_power_up NULL
+#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..e5dd7ef 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;
+ bool is_opened;
unsigned int instance;
void (*ram_init) (unsigned int instance, bool enable);
};
@@ -174,5 +177,7 @@ struct net_device *alloc_c_can_dev(void);
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);
+int c_can_power_up(struct net_device *dev);
+int c_can_power_down(struct net_device *dev);
#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..65ec232 100644
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c
@@ -255,15 +255,79 @@ 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);
+ const struct platform_device_id *id = platform_get_device_id(pdev);
+
+ if (id->driver_data != 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) {
+ dev_err(&pdev->dev, "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);
+ const struct platform_device_id *id = platform_get_device_id(pdev);
+
+ if (id->driver_data != BOSCH_D_CAN) {
+ dev_warn(&pdev->dev, "Not supported\n");
+ return 0;
+ }
+
+ ret = c_can_power_up(ndev);
+ if (ret) {
+ dev_err(&pdev->dev, "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,
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(c_can_of_table),
},
- .probe = c_can_plat_probe,
- .remove = __devexit_p(c_can_plat_remove),
- .id_table = c_can_id_table,
+ .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,
};
module_platform_driver(c_can_plat_driver);
--
1.7.9.5
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