diff mbox

[v8] can: c_can: Add runtime PM support to Bosch C_CAN/D_CAN controller

Message ID 1345452359-1137-1-git-send-email-anilkumar@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

AnilKumar, Chimata Aug. 20, 2012, 8:45 a.m. UTC
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@ti.com>
---
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 v7:
	- Incorporated Marc's commets on v7
	  * changed device pointer to c_can_priv pointer

Changes from v6:
	- Incorporated Marc's commets on v6
	  * changed dev pointer to priv
	  * removed platform_device.h include from c_can.c

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.

 drivers/net/can/c_can/c_can.c          |   24 +++++++++++++++++++++++-
 drivers/net/can/c_can/c_can.h          |    1 +
 drivers/net/can/c_can/c_can_platform.c |    6 ++++++
 3 files changed, 30 insertions(+), 1 deletion(-)

Comments

Marc Kleine-Budde Aug. 20, 2012, 10:41 a.m. UTC | #1
On 08/20/2012 10:45 AM, AnilKumar Ch wrote:
> 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@ti.com>
> ---
> 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 v7:
> 	- Incorporated Marc's commets on v7
> 	  * changed device pointer to c_can_priv pointer

looks good.

[...]

> --- 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);

I think this will end up in a NULL pointer deferf.

>  	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;
> 

Marc
Marc Kleine-Budde Aug. 20, 2012, 10:57 a.m. UTC | #2
On 08/20/2012 12:41 PM, Marc Kleine-Budde wrote:
> On 08/20/2012 10:45 AM, AnilKumar Ch wrote:
>> 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@ti.com>
>> ---
>> 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 v7:
>> 	- Incorporated Marc's commets on v7
>> 	  * changed device pointer to c_can_priv pointer
> 
> looks good.
> 
> [...]
> 
>> --- 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);
> 
> I think this will end up in a NULL pointer deferf.

Should be no problem, as you're using pdev->dev not priv->device.

Sorry for the noise :)

Marc
AnilKumar, Chimata Aug. 20, 2012, 11:03 a.m. UTC | #3
On Mon, Aug 20, 2012 at 16:27:53, Marc Kleine-Budde wrote:
> On 08/20/2012 12:41 PM, Marc Kleine-Budde wrote:
> > On 08/20/2012 10:45 AM, AnilKumar Ch wrote:
> >> 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@ti.com>
> >> ---
> >> 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 v7:
> >> 	- Incorporated Marc's commets on v7
> >> 	  * changed device pointer to c_can_priv pointer
> > 
> > looks good.
> > 
> > [...]
> > 
> >> --- 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);
> > 
> > I think this will end up in a NULL pointer deferf.
> 
> Should be no problem, as you're using pdev->dev not priv->device.
> 
> Sorry for the noise :)
> 

One more catch here, return path is not proper.

exit_free_device: should contain only free_c_can_dev(dev); 

Regards
AnilKumar
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AnilKumar, Chimata Aug. 20, 2012, 11:06 a.m. UTC | #4
On Mon, Aug 20, 2012 at 16:33:43, AnilKumar, Chimata wrote:
> On Mon, Aug 20, 2012 at 16:27:53, Marc Kleine-Budde wrote:
> > On 08/20/2012 12:41 PM, Marc Kleine-Budde wrote:
> > > On 08/20/2012 10:45 AM, AnilKumar Ch wrote:
> > >> 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@ti.com>
> > >> ---
> > >> 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 v7:
> > >> 	- Incorporated Marc's commets on v7
> > >> 	  * changed device pointer to c_can_priv pointer
> > > 
> > > looks good.
> > > 
> > > [...]
> > > 
> > >> --- 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);
> > > 
> > > I think this will end up in a NULL pointer deferf.
> > 
> > Should be no problem, as you're using pdev->dev not priv->device.
> > 
> > Sorry for the noise :)
> > 
> 
> One more catch here, return path is not proper.
> 
> exit_free_device: should contain only free_c_can_dev(dev);

And second goto exit_free_device; call should modify to
goto exit_clear_drvdata;

return path looks like this

exit_clear_drvdata:
	platform_set_drvdata(pdev, NULL);
	pm_runtime_disable(&pdev->dev);
exit_free_device:
	free_c_can_dev(dev);
...

Regards
AnilKumar
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Marc Kleine-Budde Aug. 20, 2012, 11:11 a.m. UTC | #5
On 08/20/2012 01:06 PM, AnilKumar, Chimata wrote:
> On Mon, Aug 20, 2012 at 16:33:43, AnilKumar, Chimata wrote:
>> On Mon, Aug 20, 2012 at 16:27:53, Marc Kleine-Budde wrote:
>>> On 08/20/2012 12:41 PM, Marc Kleine-Budde wrote:
>>>> On 08/20/2012 10:45 AM, AnilKumar Ch wrote:
>>>>> 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@ti.com>
>>>>> ---
>>>>> 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 v7:
>>>>> 	- Incorporated Marc's commets on v7
>>>>> 	  * changed device pointer to c_can_priv pointer
>>>>
>>>> looks good.
>>>>
>>>> [...]
>>>>
>>>>> --- 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);
>>>>
>>>> I think this will end up in a NULL pointer deferf.
>>>
>>> Should be no problem, as you're using pdev->dev not priv->device.
>>>
>>> Sorry for the noise :)
>>>
>>
>> One more catch here, return path is not proper.
>>
>> exit_free_device: should contain only free_c_can_dev(dev);
> 
> And second goto exit_free_device; call should modify to
> goto exit_clear_drvdata;
> 
> return path looks like this
> 
> exit_clear_drvdata:
> 	platform_set_drvdata(pdev, NULL);
> 	pm_runtime_disable(&pdev->dev);
> exit_free_device:
> 	free_c_can_dev(dev);
> ...

yes, please send a V9
diff mbox

Patch

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 4c538e3..966d318 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -34,6 +34,7 @@ 
 #include <linux/if_ether.h>
 #include <linux/list.h>
 #include <linux/io.h>
+#include <linux/pm_runtime.h>
 
 #include <linux/can.h>
 #include <linux/can/dev.h>
@@ -201,6 +202,18 @@  static const struct can_bittiming_const c_can_bittiming_const = {
 	.brp_inc = 1,
 };
 
+static inline void c_can_pm_runtime_get_sync(struct c_can_priv *priv)
+{
+	if (priv->device)
+		pm_runtime_get_sync(priv->device);
+}
+
+static inline void c_can_pm_runtime_put_sync(struct c_can_priv *priv)
+{
+	if (priv->device)
+		pm_runtime_put_sync(priv->device);
+}
+
 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 +686,15 @@  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);
+
 	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);
+
 	return 0;
 }
 
@@ -1053,11 +1070,13 @@  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);
+
 	/* 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 +1098,8 @@  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);
 	return err;
 }
 
@@ -1091,6 +1112,7 @@  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);
 
 	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;