pinctrl: st: add irq_request/release_resources callbacks

BugLink: http://bugs.launchpad.net/bugs/1745054

[ Upstream commit e855fa9a ]

When using GPIO as IRQ source, the GPIO must be configured
in INPUT. Callbacks 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 <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/pinctrl/pinctrl-st.c

@@ -1338,6 +1338,22 @@ 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);
+
+	st_gpio_direction_input(gc, d->hwirq);
+
+	return gpiochip_lock_as_irq(gc, d->hwirq);
+}
+
+static void st_gpio_irq_release_resources(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+
+	gpiochip_unlock_as_irq(gc, d->hwirq);
+}
+
 static int st_gpio_irq_set_type(struct irq_data *d, unsigned type)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
@@ -1494,6 +1510,8 @@ static struct gpio_chip st_gpio_template = {
 
 static struct irq_chip st_gpio_irqchip = {
 	.name			= "GPIO",
+	.irq_request_resources	= st_gpio_irq_request_resources,
+	.irq_release_resources	= st_gpio_irq_release_resources,
 	.irq_disable		= st_gpio_irq_mask,
 	.irq_mask		= st_gpio_irq_mask,
 	.irq_unmask		= st_gpio_irq_unmask,