[PATCH] gpio: bcm-kona: Add irq_set_wake method

[PATCH] gpio: bcm-kona: Add irq_set_wake method

[Tim Kryger]

If a consumer of a GPIO-based IRQ identifies itself as wanting to
have the capability to wake up the system through that interrupt,
update the flags to keep that interrupt enabled in suspend.

Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
---
 drivers/gpio/gpio-bcm-kona.c |   19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/gpio/gpio-bcm-kona.c b/drivers/gpio/gpio-bcm-kona.c
index 3f6b33c..b0e0971 100644
--- a/drivers/gpio/gpio-bcm-kona.c
+++ b/drivers/gpio/gpio-bcm-kona.c
@@ -20,6 +20,7 @@
 #include <linux/module.h>
 #include <linux/irqdomain.h>
 #include <linux/irqchip/chained_irq.h>
+#include <linux/interrupt.h>
 
 #define BCM_GPIO_PASSWD				0x00a5a501
 #define GPIO_PER_BANK				32
@@ -340,6 +341,23 @@ static void bcm_kona_gpio_irq_ack(struct irq_data *d)
 	spin_unlock_irqrestore(&kona_gpio->lock, flags);
 }
 
+#ifdef CONFIG_SUSPEND
+static int bcm_kona_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
+{
+
+	struct irq_desc *desc = container_of(d, struct irq_desc, irq_data);
+
+	if (on)
+		desc->action->flags |= IRQF_NO_SUSPEND;
+	else
+		desc->action->flags &= ~IRQF_NO_SUSPEND;
+
+	return 0;
+}
+#else
+#define bcm_kona_gpio_irq_set_wake NULL
+#endif
+
 static void bcm_kona_gpio_irq_mask(struct irq_data *d)
 {
 	struct bcm_kona_gpio *kona_gpio;
@@ -494,6 +512,7 @@ static struct irq_chip bcm_gpio_irq_chip = {
 	.irq_set_type = bcm_kona_gpio_irq_set_type,
 	.irq_request_resources = bcm_kona_gpio_irq_reqres,
 	.irq_release_resources = bcm_kona_gpio_irq_relres,
+	.irq_set_wake = bcm_kona_gpio_irq_set_wake,
 };
 
 static struct __initconst of_device_id bcm_kona_gpio_of_match[] = {
-- 
1.7.9.5

Re: [PATCH] gpio: bcm-kona: Add irq_set_wake method

[Linus Walleij]

On Fri, Apr 11, 2014 at 2:00 AM, Tim Kryger <tim.kryger@linaro.org> wrote:

> If a consumer of a GPIO-based IRQ identifies itself as wanting to
> have the capability to wake up the system through that interrupt,
> update the flags to keep that interrupt enabled in suspend.
>
> Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
(...)
> +#ifdef CONFIG_SUSPEND
> +static int bcm_kona_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
> +{
> +
> +       struct irq_desc *desc = container_of(d, struct irq_desc, irq_data);
> +
> +       if (on)
> +               desc->action->flags |= IRQF_NO_SUSPEND;
> +       else
> +               desc->action->flags &= ~IRQF_NO_SUSPEND;
> +
> +       return 0;
> +}
> +#else
> +#define bcm_kona_gpio_irq_set_wake NULL
> +#endif

Tglx: is this generally speaking the right thing to do for a cascaded
irqchip? (It looks a bit odd but makes some sense.)

>  static void bcm_kona_gpio_irq_mask(struct irq_data *d)
>  {
>         struct bcm_kona_gpio *kona_gpio;
> @@ -494,6 +512,7 @@ static struct irq_chip bcm_gpio_irq_chip = {
>         .irq_set_type = bcm_kona_gpio_irq_set_type,
>         .irq_request_resources = bcm_kona_gpio_irq_reqres,
>         .irq_release_resources = bcm_kona_gpio_irq_relres,
> +       .irq_set_wake = bcm_kona_gpio_irq_set_wake,
>  };

So I have introduced the generic GPIO irqchip helpers in order to avoid
fixing exactly this type of bug in 200 different places.

Can you take this action:

(A) Convert the BCM kona driver to use the genric GPIO irqchip
helpers e.g. in the manner of this patch:
http://marc.info/?l=linux-gpio&m=139696011031186&w=2

(B) Make exactly this bug fix in the gpiolib irqchip helpers,
by partching drivers/gpio/gpiolib.c instead?

That way we solve the problem for *several* chips in one go.

Yours,
Linus Walleij