RE: [PATCH] pinctrl: at91: add the config GPIO_OUTPUT_x

[Yang, Wenyou]

Hi JC,

> -----Original Message-----
> From: Yang, Wenyou
> Sent: Wednesday, March 05, 2014 1:32 PM
> To: Jean-Christophe PLAGNIOL-VILLARD
> Cc: linus.walleij@xxxxxxxxxx; b.brezillon@xxxxxxxxxxx; <linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx> mailing list; Linux Kernel list;
> devicetree@xxxxxxxxxxxxxxx; robh+dt@xxxxxxxxxx; pawel.moll@xxxxxxx;
> mark.rutland@xxxxxxx; ijc+devicetree@xxxxxxxxxxxxxx;
> galak@xxxxxxxxxxxxxx
> Subject: RE: [PATCH] pinctrl: at91: add the config GPIO_OUTPUT_x
> 
> Hi JC,
> 
> > -----Original Message-----
> > From: Jean-Christophe PLAGNIOL-VILLARD [mailto:plagnioj@xxxxxxxxxxxx]
> > Sent: Wednesday, March 05, 2014 12:58 PM
> > To: Yang, Wenyou
> > Cc: Jean-Christophe PLAGNIOL-VILLARD; linus.walleij@xxxxxxxxxx;
> > b.brezillon@xxxxxxxxxxx; <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>
> > mailing list; Linux Kernel list; devicetree@xxxxxxxxxxxxxxx;
> > robh+dt@xxxxxxxxxx; pawel.moll@xxxxxxx; mark.rutland@xxxxxxx;
> > ijc+devicetree@xxxxxxxxxxxxxx; galak@xxxxxxxxxxxxxx
> > Subject: Re: [PATCH] pinctrl: at91: add the config GPIO_OUTPUT_x
> >
> >
> > On Mar 5, 2014, at 9:53 AM, Wenyou Yang <wenyou.yang@xxxxxxxxx> wrote:
> >
> > > In order to support the pinctrl sleep state.
> >
> > As I said before NACK
> >
> > this is not the job of the pinctrl to describe gpio output or input
> > state
> But according to what said in the section "GPIO mode pitfalls" of
> Documentation/pinctrl.txt.
> It should be handle by the pinctrl.
> 
> If not, to deal with the sleep state will be very complicated.
> Muxing the pins for FUNCTION to enable peripheral, then twist them over
> to GPIO mode and use gpio_direction_output() to drive it HIGH or LOW
> during sleep.
> 
> --->8 ------------
> The solution is to not think that what the datasheet calls "GPIO mode"
> has to be handled by the <linux/gpio.h> interface. Instead view this as
> a certain pin config setting. Look in e.g. <linux/pinctrl/pinconf-
> generic.h> and you find this in the documentation:
> 
>   PIN_CONFIG_OUTPUT: this will configure the pin in output, use argument
>      1 to indicate high level, argument 0 to indicate low level.
> 
> So it is perfectly possible to push a pin into "GPIO mode" and drive the
> line low as part of the usual pin control map.
> ---<8 ------------

Do you have any feedback?

Thanks,
Wenyou Yang

> 
> >
> > Best Regards,
> > J.
> > >
> > > Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx>
> > > ---
> > > Hi Linus,
> > >
> > > The patch is based on branch: for-next
> > > git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
> > >
> > > Best Regards,
> > > Wenyou Yang
> > >
> > > drivers/pinctrl/pinctrl-at91.c     |   31
> > +++++++++++++++++++++++++++++++
> > > include/dt-bindings/pinctrl/at91.h |    2 ++
> > > 2 files changed, 33 insertions(+)
> > >
> > > diff --git a/drivers/pinctrl/pinctrl-at91.c
> > > b/drivers/pinctrl/pinctrl-at91.c index 5d24aae..fc51e59 100644
> > > --- a/drivers/pinctrl/pinctrl-at91.c
> > > +++ b/drivers/pinctrl/pinctrl-at91.c
> > > @@ -62,6 +62,8 @@ static int gpio_banks;
> > > #define DEGLITCH	(1 << 2)
> > > #define PULL_DOWN	(1 << 3)
> > > #define DIS_SCHMIT	(1 << 4)
> > > +#define GPIO_OUTPUT_HIGH	(1 << 5)
> > > +#define GPIO_OUTPUT_LOW		(1 << 6)
> > > #define DEBOUNCE	(1 << 16)
> > > #define DEBOUNCE_VAL_SHIFT	17
> > > #define DEBOUNCE_VAL	(0x3fff << DEBOUNCE_VAL_SHIFT)
> > > @@ -152,12 +154,15 @@ struct at91_pinctrl_mux_ops {
> > > 	void (*set_pulldown)(void __iomem *pio, unsigned mask, bool is_on);
> > > 	bool (*get_schmitt_trig)(void __iomem *pio, unsigned pin);
> > > 	void (*disable_schmitt_trig)(void __iomem *pio, unsigned mask);
> > > +	bool (*get_gpio_output)(void __iomem *pio, unsigned mask);
> > > +	void (*set_gpio_output)(void __iomem *pio, unsigned mask, bool
> > > +is_high);
> > > 	/* irq */
> > > 	int (*irq_type)(struct irq_data *d, unsigned type); };
> > >
> > > static int gpio_irq_type(struct irq_data *d, unsigned type); static
> > > int alt_gpio_irq_type(struct irq_data *d, unsigned type);
> > > +static void at91_mux_gpio_enable(void __iomem *pio, unsigned mask,
> > > +bool input);
> > >
> > > struct at91_pinctrl {
> > > 	struct device		*dev;
> > > @@ -472,6 +477,20 @@ static bool at91_mux_pio3_get_schmitt_trig(void
> > __iomem *pio, unsigned pin)
> > > 	return (__raw_readl(pio + PIO_SCHMITT) >> pin) & 0x1; }
> > >
> > > +static bool at91_mux_pio3_get_gpio_output(void __iomem *pio,
> > > +unsigned
> > > +pin) {
> > > +	return (__raw_readl(pio + PIO_ODSR) >> pin) & 0x1; }
> > > +
> > > +static void at91_mux_pio3_set_gpio_output(void __iomem *pio,
> > > +						unsigned mask,
> > > +						bool is_high)
> > > +{
> > > +	at91_mux_gpio_enable(pio, mask, 0);
> > > +	writel_relaxed(mask, pio + (is_high ? PIO_SODR : PIO_CODR)); }
> > > +
> > > +
> > > static struct at91_pinctrl_mux_ops at91rm9200_ops = {
> > > 	.get_periph	= at91_mux_get_periph,
> > > 	.mux_A_periph	= at91_mux_set_A_periph,
> > > @@ -495,6 +514,8 @@ static struct at91_pinctrl_mux_ops
> > > at91sam9x5_ops
> > = {
> > > 	.set_pulldown	= at91_mux_pio3_set_pulldown,
> > > 	.get_schmitt_trig = at91_mux_pio3_get_schmitt_trig,
> > > 	.disable_schmitt_trig = at91_mux_pio3_disable_schmitt_trig,
> > > +	.get_gpio_output = at91_mux_pio3_get_gpio_output,
> > > +	.set_gpio_output = at91_mux_pio3_set_gpio_output,
> > > 	.irq_type	= alt_gpio_irq_type,
> > > };
> > >
> > > @@ -741,6 +762,10 @@ static int at91_pinconf_get(struct pinctrl_dev
> > *pctldev,
> > > 		*config |= PULL_DOWN;
> > > 	if (info->ops->get_schmitt_trig && info->ops->get_schmitt_trig(pio,
> > pin))
> > > 		*config |= DIS_SCHMIT;
> > > +	if (info->ops->get_gpio_output) {
> > > +		*config |= info->ops->get_gpio_output(pio, pin) ?
> > > +					GPIO_OUTPUT_HIGH : GPIO_OUTPUT_LOW;
> > > +	}
> > >
> > > 	return 0;
> > > }
> > > @@ -778,6 +803,12 @@ static int at91_pinconf_set(struct pinctrl_dev
> > *pctldev,
> > > 			info->ops->set_pulldown(pio, mask, config & PULL_DOWN);
> > > 		if (info->ops->disable_schmitt_trig && config & DIS_SCHMIT)
> > > 			info->ops->disable_schmitt_trig(pio, mask);
> > > +		if (info->ops->set_gpio_output) {
> > > +			if (config & GPIO_OUTPUT_HIGH)
> > > +				info->ops->set_gpio_output(pio, mask, 1);
> > > +			if (config & GPIO_OUTPUT_LOW)
> > > +				info->ops->set_gpio_output(pio, mask, 0);
> > > +		};
> > >
> > > 	} /* for each config */
> > >
> > > diff --git a/include/dt-bindings/pinctrl/at91.h
> > > b/include/dt-bindings/pinctrl/at91.h
> > > index 0fee6ff..e799268 100644
> > > --- a/include/dt-bindings/pinctrl/at91.h
> > > +++ b/include/dt-bindings/pinctrl/at91.h
> > > @@ -15,6 +15,8 @@
> > > #define AT91_PINCTRL_DEGLITCH		(1 << 2)
> > > #define AT91_PINCTRL_PULL_DOWN		(1 << 3)
> > > #define AT91_PINCTRL_DIS_SCHMIT		(1 << 4)
> > > +#define AT91_PINCTRL_OUTPUT_HIGH	(1 << 5)
> > > +#define AT91_PINCTRL_OUTPUT_LOW		(1 << 6)
> > > #define AT91_PINCTRL_DEBOUNCE		(1 << 16)
> > > #define AT91_PINCTRL_DEBOUNCE_VAL(x)	(x << 17)
> > >
> > > --
> > > 1.7.9.5
> > >

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