[PATCH 1/1] pinctrl: st: add irq_request_resources callback

Subsystems: arm/sti architecture, pin control subsystem, the rest

STALE3481d

3 messages, 2 authors, 2017-03-16 · open the first message on its own page

[PATCH 1/1] pinctrl: st: add irq_request_resources callback

From: <hidden>
Date: 2017-02-27 14:45:33

From: Patrice Chotard <redacted>

When using GPIO as IRQ source, the GPIO must be configured
in INPUT. The callback dedicated for this was missing in
pinctrl-st driver.

This fix the following kernel error when trying to lock a gpio
as IRQ:

[    7.521095] gpio gpiochip7: (PIO11): gpiochip_lock_as_irq: tried to flag a GPIO set as output for IRQ
[    7.526018] gpio gpiochip7: (PIO11): unable to lock HW IRQ 6 for IRQ
[    7.529405] genirq: Failed to request resources for 0-0053 (irq 81) on irqchip GPIO

Signed-off-by: Patrice Chotard <redacted>
---
 drivers/pinctrl/pinctrl-st.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)
diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
index 676efcc..84c2af8 100644
--- a/drivers/pinctrl/pinctrl-st.c
+++ b/drivers/pinctrl/pinctrl-st.c
@@ -1285,6 +1285,14 @@ static void st_gpio_irq_unmask(struct irq_data *d)
 	writel(BIT(d->hwirq), bank->base + REG_PIO_SET_PMASK);
 }
 
+static int st_gpio_irq_request_resources(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	int pin = d->hwirq;
+
+	return st_gpio_direction_input(gc, pin);
+}
+
 static int st_gpio_irq_set_type(struct irq_data *d, unsigned type)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
@@ -1438,12 +1446,13 @@ static void st_gpio_irqmux_handler(struct irq_desc *desc)
 };
 
 static struct irq_chip st_gpio_irqchip = {
-	.name		= "GPIO",
-	.irq_disable	= st_gpio_irq_mask,
-	.irq_mask	= st_gpio_irq_mask,
-	.irq_unmask	= st_gpio_irq_unmask,
-	.irq_set_type	= st_gpio_irq_set_type,
-	.flags		= IRQCHIP_SKIP_SET_WAKE,
+	.name			= "GPIO",
+	.irq_request_resources	= st_gpio_irq_request_resources,
+	.irq_disable		= st_gpio_irq_mask,
+	.irq_mask		= st_gpio_irq_mask,
+	.irq_unmask		= st_gpio_irq_unmask,
+	.irq_set_type		= st_gpio_irq_set_type,
+	.flags			= IRQCHIP_SKIP_SET_WAKE,
 };
 
 static int st_gpiolib_register_bank(struct st_pinctrl *info,
-- 
1.9.1

Re: [PATCH 1/1] pinctrl: st: add irq_request_resources callback

From: Linus Walleij <hidden>
Date: 2017-03-14 14:06:04

On Mon, Feb 27, 2017 at 2:49 PM,  [off-list ref] wrote:
From: Patrice Chotard <redacted>

When using GPIO as IRQ source, the GPIO must be configured
in INPUT. The callback dedicated for this was missing in
pinctrl-st driver.

This fix the following kernel error when trying to lock a gpio
as IRQ:

[    7.521095] gpio gpiochip7: (PIO11): gpiochip_lock_as_irq: tried to flag a GPIO set as output for IRQ
[    7.526018] gpio gpiochip7: (PIO11): unable to lock HW IRQ 6 for IRQ
[    7.529405] genirq: Failed to request resources for 0-0053 (irq 81) on irqchip GPIO

Signed-off-by: Patrice Chotard <redacted>
I see what problem you are trying to solve.
+static int st_gpio_irq_request_resources(struct irq_data *d)
+{
+       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+       int pin = d->hwirq;
+
+       return st_gpio_direction_input(gc, pin);
+}
(...)
+       .irq_request_resources  = st_gpio_irq_request_resources,
But this is just hiding the problem I'm afraid.

Now thay you override .irq_request_resources()
gpiochip_irq_reqres() will not be called, so then you have
to lock the irq in the driver, with something like:

ret = gpiochip_lock_as_irq(&chip->gc, d->hwirq);
        if (ret)
                goto out;

You also have to implement the .irq_release_resources()
callback and unlock the IRQ there.

Yours,
Linus Walleij

Re: [PATCH 1/1] pinctrl: st: add irq_request_resources callback

From: Patrice CHOTARD <hidden>
Date: 2017-03-16 15:40:24


On 03/14/2017 03:05 PM, Linus Walleij wrote:
On Mon, Feb 27, 2017 at 2:49 PM,  [off-list ref] wrote:
quoted
From: Patrice Chotard <redacted>

When using GPIO as IRQ source, the GPIO must be configured
in INPUT. The callback dedicated for this was missing in
pinctrl-st driver.

This fix the following kernel error when trying to lock a gpio
as IRQ:

[    7.521095] gpio gpiochip7: (PIO11): gpiochip_lock_as_irq: tried to flag a GPIO set as output for IRQ
[    7.526018] gpio gpiochip7: (PIO11): unable to lock HW IRQ 6 for IRQ
[    7.529405] genirq: Failed to request resources for 0-0053 (irq 81) on irqchip GPIO

Signed-off-by: Patrice Chotard <redacted>
I see what problem you are trying to solve.
quoted
+static int st_gpio_irq_request_resources(struct irq_data *d)
+{
+       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+       int pin = d->hwirq;
+
+       return st_gpio_direction_input(gc, pin);
+}
(...)
quoted
+       .irq_request_resources  = st_gpio_irq_request_resources,
But this is just hiding the problem I'm afraid.
Hi Linus
Now thay you override .irq_request_resources()
gpiochip_irq_reqres() will not be called, so then you have
to lock the irq in the driver, with something like:

ret = gpiochip_lock_as_irq(&chip->gc, d->hwirq);
        if (ret)
                goto out;
Ah yes, i didn't noticed that point, thanks for the tips.
You also have to implement the .irq_release_resources()
callback and unlock the IRQ there.
In this case, yes the release becomes mandatory.

I will send a v2.

Thanks

Patrice
Yours,
Linus Walleij
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