[v2,8/9] atmel_flexcom: Support backup mode

Message ID 20170915140411.31716-9-romain.izard.pro@gmail.com
State New
Headers show
Series
  • Various patches for SAMA5D2 backup mode
Related show

Commit Message

Romain Izard Sept. 15, 2017, 2:04 p.m.
The controller used by a flexcom module is configured at boot, and left
alone after this. As the configuration will be lost after backup mode,
restore the state of the flexcom driver on resume.

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
---
 drivers/mfd/atmel-flexcom.c | 65 ++++++++++++++++++++++++++++++++++-----------
 1 file changed, 50 insertions(+), 15 deletions(-)

Comments

Nicolas Ferre Sept. 19, 2017, 9:29 a.m. | #1
On 15/09/2017 at 16:04, Romain Izard wrote:
> The controller used by a flexcom module is configured at boot, and left
> alone after this. As the configuration will be lost after backup mode,
> restore the state of the flexcom driver on resume.
> 
> Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>

Tested-by: Nicolas Ferre <nicolas.ferre@microchip.com>
On sama5d2 Xplained board (i2c0 from flexcom 4).
and obviously:
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>

Thanks Romain!

Regards,

> ---
>  drivers/mfd/atmel-flexcom.c | 65 ++++++++++++++++++++++++++++++++++-----------
>  1 file changed, 50 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/mfd/atmel-flexcom.c b/drivers/mfd/atmel-flexcom.c
> index 064bde9cff5a..ef1235c4a179 100644
> --- a/drivers/mfd/atmel-flexcom.c
> +++ b/drivers/mfd/atmel-flexcom.c
> @@ -39,34 +39,44 @@
>  #define FLEX_MR_OPMODE(opmode)	(((opmode) << FLEX_MR_OPMODE_OFFSET) &	\
>  				 FLEX_MR_OPMODE_MASK)
>  
> +struct atmel_flexcom {
> +	void __iomem *base;
> +	u32 opmode;
> +	struct clk *clk;
> +};
>  
>  static int atmel_flexcom_probe(struct platform_device *pdev)
>  {
>  	struct device_node *np = pdev->dev.of_node;
> -	struct clk *clk;
>  	struct resource *res;
> -	void __iomem *base;
> -	u32 opmode;
> +	struct atmel_flexcom *afc;
>  	int err;
> +	u32 val;
> +
> +	afc = devm_kzalloc(&pdev->dev, sizeof(*afc), GFP_KERNEL);
> +	if (!afc)
> +		return -ENOMEM;
>  
> -	err = of_property_read_u32(np, "atmel,flexcom-mode", &opmode);
> +	platform_set_drvdata(pdev, afc);
> +
> +	err = of_property_read_u32(np, "atmel,flexcom-mode", &afc->opmode);
>  	if (err)
>  		return err;
>  
> -	if (opmode < ATMEL_FLEXCOM_MODE_USART ||
> -	    opmode > ATMEL_FLEXCOM_MODE_TWI)
> +	if (afc->opmode < ATMEL_FLEXCOM_MODE_USART ||
> +	    afc->opmode > ATMEL_FLEXCOM_MODE_TWI)
>  		return -EINVAL;
>  
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	base = devm_ioremap_resource(&pdev->dev, res);
> -	if (IS_ERR(base))
> -		return PTR_ERR(base);
> +	afc->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(afc->base))
> +		return PTR_ERR(afc->base);
>  
> -	clk = devm_clk_get(&pdev->dev, NULL);
> -	if (IS_ERR(clk))
> -		return PTR_ERR(clk);
> +	afc->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(afc->clk))
> +		return PTR_ERR(afc->clk);
>  
> -	err = clk_prepare_enable(clk);
> +	err = clk_prepare_enable(afc->clk);
>  	if (err)
>  		return err;
>  
> @@ -76,9 +86,10 @@ static int atmel_flexcom_probe(struct platform_device *pdev)
>  	 * inaccessible and are read as zero. Also the external I/O lines of the
>  	 * Flexcom are muxed to reach the selected device.
>  	 */
> -	writel(FLEX_MR_OPMODE(opmode), base + FLEX_MR);
> +	val = FLEX_MR_OPMODE(afc->opmode);
> +	writel(val, afc->base + FLEX_MR);
>  
> -	clk_disable_unprepare(clk);
> +	clk_disable_unprepare(afc->clk);
>  
>  	return devm_of_platform_populate(&pdev->dev);
>  }
> @@ -89,10 +100,34 @@ static const struct of_device_id atmel_flexcom_of_match[] = {
>  };
>  MODULE_DEVICE_TABLE(of, atmel_flexcom_of_match);
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int atmel_flexcom_resume(struct device *dev)
> +{
> +	struct atmel_flexcom *afc = dev_get_drvdata(dev);
> +	int err;
> +	u32 val;
> +
> +	err = clk_prepare_enable(afc->clk);
> +	if (err)
> +		return err;
> +
> +	val = FLEX_MR_OPMODE(afc->opmode),
> +	writel(val, afc->base + FLEX_MR);
> +
> +	clk_disable_unprepare(afc->clk);
> +
> +	return 0;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(atmel_flexcom_pm_ops, NULL,
> +			 atmel_flexcom_resume);
> +
>  static struct platform_driver atmel_flexcom_driver = {
>  	.probe	= atmel_flexcom_probe,
>  	.driver	= {
>  		.name		= "atmel_flexcom",
> +		.pm		= &atmel_flexcom_pm_ops,
>  		.of_match_table	= atmel_flexcom_of_match,
>  	},
>  };
>
Lee Jones Sept. 19, 2017, 3:25 p.m. | #2
On Tue, 19 Sep 2017, Nicolas Ferre wrote:

> On 15/09/2017 at 16:04, Romain Izard wrote:
> > The controller used by a flexcom module is configured at boot, and left
> > alone after this. As the configuration will be lost after backup mode,
> > restore the state of the flexcom driver on resume.
> > 
> > Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
> 
> Tested-by: Nicolas Ferre <nicolas.ferre@microchip.com>
> On sama5d2 Xplained board (i2c0 from flexcom 4).
> and obviously:
> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
> 
> Thanks Romain!
> 
> Regards,
> 
> > ---
> >  drivers/mfd/atmel-flexcom.c | 65 ++++++++++++++++++++++++++++++++++-----------
> >  1 file changed, 50 insertions(+), 15 deletions(-)

This is the first time I've seen this patch.  Why's that?
Romain Izard Sept. 20, 2017, 8:30 a.m. | #3
2017-09-19 17:25 GMT+02:00 Lee Jones <lee.jones@linaro.org>:
> On Tue, 19 Sep 2017, Nicolas Ferre wrote:
>
>> On 15/09/2017 at 16:04, Romain Izard wrote:
>> > The controller used by a flexcom module is configured at boot, and left
>> > alone after this. As the configuration will be lost after backup mode,
>> > restore the state of the flexcom driver on resume.
>> >
>> > Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
>>
>> Tested-by: Nicolas Ferre <nicolas.ferre@microchip.com>
>> On sama5d2 Xplained board (i2c0 from flexcom 4).
>> and obviously:
>> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
>>
>> Thanks Romain!
>>
>> Regards,
>>
>> > ---
>> >  drivers/mfd/atmel-flexcom.c | 65 ++++++++++++++++++++++++++++++++++-----------
>> >  1 file changed, 50 insertions(+), 15 deletions(-)
>
> This is the first time I've seen this patch.  Why's that?
>

As the patchset covers many subsystems, get_maintainers.pl provided a
very long list of both developpers and mailing lists (28). I thought it
was a good idea to shorten it a little. Bad idea. Sorry.

Best regards,
Alexandre Belloni Sept. 20, 2017, 9:18 a.m. | #4
On 20/09/2017 at 10:30:31 +0200, Romain Izard wrote:
> 2017-09-19 17:25 GMT+02:00 Lee Jones <lee.jones@linaro.org>:
> > On Tue, 19 Sep 2017, Nicolas Ferre wrote:
> >
> >> On 15/09/2017 at 16:04, Romain Izard wrote:
> >> > The controller used by a flexcom module is configured at boot, and left
> >> > alone after this. As the configuration will be lost after backup mode,
> >> > restore the state of the flexcom driver on resume.
> >> >
> >> > Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
> >>
> >> Tested-by: Nicolas Ferre <nicolas.ferre@microchip.com>
> >> On sama5d2 Xplained board (i2c0 from flexcom 4).
> >> and obviously:
> >> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
> >>
> >> Thanks Romain!
> >>
> >> Regards,
> >>
> >> > ---
> >> >  drivers/mfd/atmel-flexcom.c | 65 ++++++++++++++++++++++++++++++++++-----------
> >> >  1 file changed, 50 insertions(+), 15 deletions(-)
> >
> > This is the first time I've seen this patch.  Why's that?
> >
> 
> As the patchset covers many subsystems, get_maintainers.pl provided a
> very long list of both developpers and mailing lists (28). I thought it
> was a good idea to shorten it a little. Bad idea. Sorry.
> 

I think the correct way of handling that would have been to send each
patch to the proper subsystem as there are no dependency here.

Patch

diff --git a/drivers/mfd/atmel-flexcom.c b/drivers/mfd/atmel-flexcom.c
index 064bde9cff5a..ef1235c4a179 100644
--- a/drivers/mfd/atmel-flexcom.c
+++ b/drivers/mfd/atmel-flexcom.c
@@ -39,34 +39,44 @@ 
 #define FLEX_MR_OPMODE(opmode)	(((opmode) << FLEX_MR_OPMODE_OFFSET) &	\
 				 FLEX_MR_OPMODE_MASK)
 
+struct atmel_flexcom {
+	void __iomem *base;
+	u32 opmode;
+	struct clk *clk;
+};
 
 static int atmel_flexcom_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
-	struct clk *clk;
 	struct resource *res;
-	void __iomem *base;
-	u32 opmode;
+	struct atmel_flexcom *afc;
 	int err;
+	u32 val;
+
+	afc = devm_kzalloc(&pdev->dev, sizeof(*afc), GFP_KERNEL);
+	if (!afc)
+		return -ENOMEM;
 
-	err = of_property_read_u32(np, "atmel,flexcom-mode", &opmode);
+	platform_set_drvdata(pdev, afc);
+
+	err = of_property_read_u32(np, "atmel,flexcom-mode", &afc->opmode);
 	if (err)
 		return err;
 
-	if (opmode < ATMEL_FLEXCOM_MODE_USART ||
-	    opmode > ATMEL_FLEXCOM_MODE_TWI)
+	if (afc->opmode < ATMEL_FLEXCOM_MODE_USART ||
+	    afc->opmode > ATMEL_FLEXCOM_MODE_TWI)
 		return -EINVAL;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	base = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(base))
-		return PTR_ERR(base);
+	afc->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(afc->base))
+		return PTR_ERR(afc->base);
 
-	clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(clk))
-		return PTR_ERR(clk);
+	afc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(afc->clk))
+		return PTR_ERR(afc->clk);
 
-	err = clk_prepare_enable(clk);
+	err = clk_prepare_enable(afc->clk);
 	if (err)
 		return err;
 
@@ -76,9 +86,10 @@  static int atmel_flexcom_probe(struct platform_device *pdev)
 	 * inaccessible and are read as zero. Also the external I/O lines of the
 	 * Flexcom are muxed to reach the selected device.
 	 */
-	writel(FLEX_MR_OPMODE(opmode), base + FLEX_MR);
+	val = FLEX_MR_OPMODE(afc->opmode);
+	writel(val, afc->base + FLEX_MR);
 
-	clk_disable_unprepare(clk);
+	clk_disable_unprepare(afc->clk);
 
 	return devm_of_platform_populate(&pdev->dev);
 }
@@ -89,10 +100,34 @@  static const struct of_device_id atmel_flexcom_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, atmel_flexcom_of_match);
 
+#ifdef CONFIG_PM_SLEEP
+static int atmel_flexcom_resume(struct device *dev)
+{
+	struct atmel_flexcom *afc = dev_get_drvdata(dev);
+	int err;
+	u32 val;
+
+	err = clk_prepare_enable(afc->clk);
+	if (err)
+		return err;
+
+	val = FLEX_MR_OPMODE(afc->opmode),
+	writel(val, afc->base + FLEX_MR);
+
+	clk_disable_unprepare(afc->clk);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(atmel_flexcom_pm_ops, NULL,
+			 atmel_flexcom_resume);
+
 static struct platform_driver atmel_flexcom_driver = {
 	.probe	= atmel_flexcom_probe,
 	.driver	= {
 		.name		= "atmel_flexcom",
+		.pm		= &atmel_flexcom_pm_ops,
 		.of_match_table	= atmel_flexcom_of_match,
 	},
 };