Add Runtime PM support to C_CAN/D_CAN controller. The runtime PM
APIs control clocks for C_CAN/D_CAN IP and prevent access to the
register of C_CAN/D_CAN IP when clock is turned off.
Signed-off-by: AnilKumar Ch <anilkumar@xxxxxx>
---
This patch has been tested on AM335X EVM. Due to lack of hardware
I am not able to test c_can functionality. I appreciate if anyone
can test c_can functionality with this patch.
This patch is based on "can-next/master"
Changes from v5:
- Incorporated Marc's commets on v5
* changed runtime pm calls in c_can driver to handle
the drivers which are not using platform drivers.
* added device pointer protection in c_can driver if
not passed from platform/pci driver.
Changes from v4:
- Incorporated Vaibhav H review comments on v4.
* Moved pm_runtime put/get_sync calls to appropriate positions.
- This patch is from "Add DT support to C_CAN/D_CAN controller"
patch series. Rest of the patches in this series were applied
so this v5 contains only this patch.
Signed-off-by: AnilKumar Ch <anilkumar@xxxxxx>
---
drivers/net/can/c_can/c_can.c | 25 ++++++++++++++++++++++++-
drivers/net/can/c_can/c_can.h | 1 +
drivers/net/can/c_can/c_can_platform.c | 6 ++++++
3 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 4c538e3..64344b8 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -34,6 +34,8 @@
#include <linux/if_ether.h>
#include <linux/list.h>
#include <linux/io.h>
+#include <linux/pm_runtime.h>
+#include <linux/platform_device.h>
#include <linux/can.h>
#include <linux/can/dev.h>
@@ -201,6 +203,18 @@ static const struct can_bittiming_const c_can_bittiming_const = {
.brp_inc = 1,
};
+static inline void c_can_pm_runtime_get_sync(struct device *dev)
+{
+ if (dev)
+ pm_runtime_get_sync(dev);
+}
+
+static inline void c_can_pm_runtime_put_sync(struct device *dev)
+{
+ if (dev)
+ pm_runtime_put_sync(dev);
+}
+
static inline int get_tx_next_msg_obj(const struct c_can_priv *priv)
{
return (priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) +
@@ -673,11 +687,15 @@ static int c_can_get_berr_counter(const struct net_device *dev,
unsigned int reg_err_counter;
struct c_can_priv *priv = netdev_priv(dev);
+ c_can_pm_runtime_get_sync(priv->device);
+
reg_err_counter = priv->read_reg(priv, C_CAN_ERR_CNT_REG);
bec->rxerr = (reg_err_counter & ERR_CNT_REC_MASK) >>
ERR_CNT_REC_SHIFT;
bec->txerr = reg_err_counter & ERR_CNT_TEC_MASK;
+ c_can_pm_runtime_put_sync(priv->device);
+
return 0;
}
@@ -1053,11 +1071,13 @@ static int c_can_open(struct net_device *dev)
int err;
struct c_can_priv *priv = netdev_priv(dev);
+ c_can_pm_runtime_get_sync(priv->device);
+
/* open the can device */
err = open_candev(dev);
if (err) {
netdev_err(dev, "failed to open can device\n");
- return err;
+ goto exit_open_fail;
}
/* register interrupt handler */
@@ -1079,6 +1099,8 @@ static int c_can_open(struct net_device *dev)
exit_irq_fail:
close_candev(dev);
+exit_open_fail:
+ c_can_pm_runtime_put_sync(priv->device);
return err;
}
@@ -1091,6 +1113,7 @@ static int c_can_close(struct net_device *dev)
c_can_stop(dev);
free_irq(dev->irq, dev);
close_candev(dev);
+ c_can_pm_runtime_put_sync(priv->device);
return 0;
}
diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index 4e56baa..1437a6d 100644
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -153,6 +153,7 @@ struct c_can_priv {
struct can_priv can; /* must be the first member */
struct napi_struct napi;
struct net_device *dev;
+ struct device *device;
int tx_object;
int current_status;
int last_status;
diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
index d0a66cf..197683b 100644
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c
@@ -32,6 +32,7 @@
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
#include <linux/can/dev.h>
@@ -177,8 +178,11 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev)
goto exit_free_device;
}
+ pm_runtime_enable(&pdev->dev);
+
dev->irq = irq;
priv->base = addr;
+ priv->device = &pdev->dev;
priv->can.clock.freq = clk_get_rate(clk);
priv->priv = clk;
@@ -198,6 +202,7 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev)
exit_free_device:
platform_set_drvdata(pdev, NULL);
+ pm_runtime_disable(&pdev->dev);
free_c_can_dev(dev);
exit_iounmap:
iounmap(addr);
@@ -226,6 +231,7 @@ static int __devexit c_can_plat_remove(struct platform_device *pdev)
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(mem->start, resource_size(mem));
+ pm_runtime_disable(&pdev->dev);
clk_put(priv->priv);
return 0;
--
1.7.9.5
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