[PATCH] pinctrl: at91-pio4: handle suspend to ram

[PATCH] pinctrl: at91-pio4: handle suspend to ram

[Alexandre Belloni]

When suspending to RAM, the power to the core is cut and the register
values are lost. Save and restore more registers than just IMR.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/pinctrl/pinctrl-at91-pio4.c | 34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c
index 28bbc1bb9e6c..dc8591543dee 100644
--- a/drivers/pinctrl/pinctrl-at91-pio4.c
+++ b/drivers/pinctrl/pinctrl-at91-pio4.c
@@ -126,7 +126,11 @@ struct atmel_pioctrl {
 	struct irq_domain	*irq_domain;
 	int			*irqs;
 	unsigned		*pm_wakeup_sources;
-	unsigned		*pm_suspend_backup;
+	struct {
+		u32		imr;
+		u32		odsr;
+		u32		cfgr[ATMEL_PIO_NPINS_PER_BANK];
+	} *pm_suspend_backup;
 	struct device		*dev;
 	struct device_node	*node;
 };
@@ -830,17 +834,26 @@ static int __maybe_unused atmel_pctrl_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct atmel_pioctrl *atmel_pioctrl = platform_get_drvdata(pdev);
-	int i;
+	int i, j;
 
 	/*
 	 * For each bank, save IMR to restore it later and disable all GPIO
 	 * interrupts excepting the ones marked as wakeup sources.
 	 */
 	for (i = 0; i < atmel_pioctrl->nbanks; i++) {
-		atmel_pioctrl->pm_suspend_backup[i] =
+		atmel_pioctrl->pm_suspend_backup[i].imr =
 			atmel_gpio_read(atmel_pioctrl, i, ATMEL_PIO_IMR);
 		atmel_gpio_write(atmel_pioctrl, i, ATMEL_PIO_IDR,
 				 ~atmel_pioctrl->pm_wakeup_sources[i]);
+		atmel_pioctrl->pm_suspend_backup[i].odsr =
+			atmel_gpio_read(atmel_pioctrl, i, ATMEL_PIO_ODSR);
+		for (j = 0; j < ATMEL_PIO_NPINS_PER_BANK; j++) {
+			atmel_gpio_write(atmel_pioctrl, i,
+					 ATMEL_PIO_MSKR, BIT(j));
+			atmel_pioctrl->pm_suspend_backup[i].cfgr[j] =
+				atmel_gpio_read(atmel_pioctrl, i,
+						ATMEL_PIO_CFGR);
+		}
 	}
 
 	return 0;
@@ -850,11 +863,20 @@ static int __maybe_unused atmel_pctrl_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct atmel_pioctrl *atmel_pioctrl = platform_get_drvdata(pdev);
-	int i;
+	int i, j;
 
-	for (i = 0; i < atmel_pioctrl->nbanks; i++)
+	for (i = 0; i < atmel_pioctrl->nbanks; i++) {
 		atmel_gpio_write(atmel_pioctrl, i, ATMEL_PIO_IER,
-				 atmel_pioctrl->pm_suspend_backup[i]);
+				 atmel_pioctrl->pm_suspend_backup[i].imr);
+		atmel_gpio_write(atmel_pioctrl, i, ATMEL_PIO_SODR,
+				 atmel_pioctrl->pm_suspend_backup[i].odsr);
+		for (j = 0; j < ATMEL_PIO_NPINS_PER_BANK; j++) {
+			atmel_gpio_write(atmel_pioctrl, i,
+					 ATMEL_PIO_MSKR, BIT(j));
+			atmel_gpio_write(atmel_pioctrl, i, ATMEL_PIO_CFGR,
+					 atmel_pioctrl->pm_suspend_backup[i].cfgr[j]);
+		}
+	}
 
 	return 0;
 }
-- 
2.11.0

Re: [PATCH] pinctrl: at91-pio4: handle suspend to ram

[Linus Walleij]

On Thu, Apr 6, 2017 at 3:36 PM, Alexandre Belloni
<alexandre.belloni@free-electrons.com> wrote:

> When suspending to RAM, the power to the core is cut and the register
> values are lost. Save and restore more registers than just IMR.
>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Should this be tagged for stable?

Waiting for input from the AT91 maintainers here.

Yours,
Linus Walleij

Re: [PATCH] pinctrl: at91-pio4: handle suspend to ram

[Alexandre Belloni]

On 07/04/2017 at 12:16:22 +0200, Linus Walleij wrote:
> On Thu, Apr 6, 2017 at 3:36 PM, Alexandre Belloni
> <alexandre.belloni@free-electrons.com> wrote:
> 
> > When suspending to RAM, the power to the core is cut and the register
> > values are lost. Save and restore more registers than just IMR.
> >
> > Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> 
> Should this be tagged for stable?
> 

No because that particular suspend to ram mode is not yet implemented
upstream.

> Waiting for input from the AT91 maintainers here.
> 

Well, I've been an AT91 maintainer for 2 years now and I have done all
the AT91 pull requests since 3.16. I hope this qualifies me here.

-- 
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH] pinctrl: at91-pio4: handle suspend to ram

[Linus Walleij]

On Fri, Apr 7, 2017 at 12:48 PM, Alexandre Belloni
<alexandre.belloni@free-electrons.com> wrote:
> On 07/04/2017 at 12:16:22 +0200, Linus Walleij wrote:
>> On Thu, Apr 6, 2017 at 3:36 PM, Alexandre Belloni
>> <alexandre.belloni@free-electrons.com> wrote:
>>
>> > When suspending to RAM, the power to the core is cut and the register
>> > values are lost. Save and restore more registers than just IMR.
>> >
>> > Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
>>
>> Should this be tagged for stable?
>>
>
> No because that particular suspend to ram mode is not yet implemented
> upstream.
>
>> Waiting for input from the AT91 maintainers here.
>>
>
> Well, I've been an AT91 maintainer for 2 years now and I have done all
> the AT91 pull requests since 3.16. I hope this qualifies me here.

So much for trying to keep MAINTAINERS in my head :(

I wish there was gmail integration so I could annotate people
with roles...

Patch applied.

Yours,
Linus Walleij

Re: [PATCH] pinctrl: at91-pio4: handle suspend to ram

[Ludovic Desroches]

On Thu, Apr 06, 2017 at 03:36:23PM +0200, Alexandre Belloni wrote:
> When suspending to RAM, the power to the core is cut and the register
> values are lost. Save and restore more registers than just IMR.
> 
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> ---
>  drivers/pinctrl/pinctrl-at91-pio4.c | 34 ++++++++++++++++++++++++++++------
>  1 file changed, 28 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c
> index 28bbc1bb9e6c..dc8591543dee 100644
> --- a/drivers/pinctrl/pinctrl-at91-pio4.c
> +++ b/drivers/pinctrl/pinctrl-at91-pio4.c
> @@ -126,7 +126,11 @@ struct atmel_pioctrl {
>  	struct irq_domain	*irq_domain;
>  	int			*irqs;
>  	unsigned		*pm_wakeup_sources;
> -	unsigned		*pm_suspend_backup;
> +	struct {
> +		u32		imr;
> +		u32		odsr;
> +		u32		cfgr[ATMEL_PIO_NPINS_PER_BANK];
> +	} *pm_suspend_backup;
>  	struct device		*dev;
>  	struct device_node	*node;
>  };
> @@ -830,17 +834,26 @@ static int __maybe_unused atmel_pctrl_suspend(struct device *dev)
>  {
>  	struct platform_device *pdev = to_platform_device(dev);
>  	struct atmel_pioctrl *atmel_pioctrl = platform_get_drvdata(pdev);
> -	int i;
> +	int i, j;
>  
>  	/*
>  	 * For each bank, save IMR to restore it later and disable all GPIO
>  	 * interrupts excepting the ones marked as wakeup sources.
>  	 */
>  	for (i = 0; i < atmel_pioctrl->nbanks; i++) {
> -		atmel_pioctrl->pm_suspend_backup[i] =
> +		atmel_pioctrl->pm_suspend_backup[i].imr =
>  			atmel_gpio_read(atmel_pioctrl, i, ATMEL_PIO_IMR);
>  		atmel_gpio_write(atmel_pioctrl, i, ATMEL_PIO_IDR,
>  				 ~atmel_pioctrl->pm_wakeup_sources[i]);
> +		atmel_pioctrl->pm_suspend_backup[i].odsr =
> +			atmel_gpio_read(atmel_pioctrl, i, ATMEL_PIO_ODSR);
> +		for (j = 0; j < ATMEL_PIO_NPINS_PER_BANK; j++) {
> +			atmel_gpio_write(atmel_pioctrl, i,
> +					 ATMEL_PIO_MSKR, BIT(j));
> +			atmel_pioctrl->pm_suspend_backup[i].cfgr[j] =
> +				atmel_gpio_read(atmel_pioctrl, i,
> +						ATMEL_PIO_CFGR);
> +		}
>  	}
>  
>  	return 0;
> @@ -850,11 +863,20 @@ static int __maybe_unused atmel_pctrl_resume(struct device *dev)
>  {
>  	struct platform_device *pdev = to_platform_device(dev);
>  	struct atmel_pioctrl *atmel_pioctrl = platform_get_drvdata(pdev);
> -	int i;
> +	int i, j;
>  
> -	for (i = 0; i < atmel_pioctrl->nbanks; i++)
> +	for (i = 0; i < atmel_pioctrl->nbanks; i++) {
>  		atmel_gpio_write(atmel_pioctrl, i, ATMEL_PIO_IER,
> -				 atmel_pioctrl->pm_suspend_backup[i]);
> +				 atmel_pioctrl->pm_suspend_backup[i].imr);
> +		atmel_gpio_write(atmel_pioctrl, i, ATMEL_PIO_SODR,
> +				 atmel_pioctrl->pm_suspend_backup[i].odsr);

I would also configure CODR to be sure to be in the same state.

Otherwise: Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>

> +		for (j = 0; j < ATMEL_PIO_NPINS_PER_BANK; j++) {
> +			atmel_gpio_write(atmel_pioctrl, i,
> +					 ATMEL_PIO_MSKR, BIT(j));
> +			atmel_gpio_write(atmel_pioctrl, i, ATMEL_PIO_CFGR,
> +					 atmel_pioctrl->pm_suspend_backup[i].cfgr[j]);
> +		}
> +	}
>  
>  	return 0;
>  }
> -- 
> 2.11.0
>