[PATCH v2 6/6] pinctrl: renesas: pinctrl-rzg2l: Override irq_request/release_resources

[Prabhakar <prabhakar.csengg@xxxxxxxxx>]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

Override the default `irq_request_resources` and `irq_release_resources`
functions with `rzg2l_gpio_irq_request_resources` and
`rzg2l_gpio_irq_release_resources` in the RZ/G2L pinctrl driver.

The `rzg2l_gpio_irq_request_resources()` function now ensures that the pin
is requested by the pinctrl core before locking the GPIO as an IRQ. This
ensures that the `pinmux-pins` file in sysfs correctly reports the pin as
claimed. Additionally, the `rzg2l_gpio_direction_input()` call is moved
into the `rzg2l_gpio_irq_request_resources()` callback, as it makes sense
to configure the GPIO pin as an input after it has been requested.

The `rzg2l_gpio_irq_release_resources()` function unlocks the GPIO as an
IRQ and then frees the GPIO, ensuring proper cleanup when the IRQ is no
longer needed. This guarantees that the `pinmux-pins` file in sysfs
correctly reports the pin as unclaimed.

Also add a `pin_requested()` check in `rzg2l_gpio_free()` to return early
if the pin is already released.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
v1->v2
- No change
---
 drivers/pinctrl/renesas/pinctrl-rzg2l.c | 41 +++++++++++++++++++++----
 1 file changed, 35 insertions(+), 6 deletions(-)

diff --git a/drivers/pinctrl/renesas/pinctrl-rzg2l.c b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
index b9a8bf43a92a..47b3e296d094 100644
--- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
+++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
@@ -1772,8 +1772,12 @@ static int rzg2l_gpio_get(struct gpio_chip *chip, unsigned int offset)
 
 static void rzg2l_gpio_free(struct gpio_chip *chip, unsigned int offset)
 {
+	struct rzg2l_pinctrl *pctrl = gpiochip_get_data(chip);
 	unsigned int virq;
 
+	if (!pin_requested(pctrl->pctl, offset))
+		return;
+
 	virq = irq_find_mapping(chip->irq.domain, offset);
 	if (virq)
 		irq_dispose_mapping(virq);
@@ -2357,6 +2361,35 @@ static int rzg2l_gpio_irq_set_wake(struct irq_data *data, unsigned int on)
 	return 0;
 }
 
+static int rzg2l_gpio_irq_request_resources(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct rzg2l_pinctrl *pctrl = container_of(gc, struct rzg2l_pinctrl, gpio_chip);
+	unsigned int child = irqd_to_hwirq(d);
+	int ret;
+
+	if (!pin_requested(pctrl->pctl, child)) {
+		ret = rzg2l_gpio_request(gc, child);
+		if (ret)
+			return ret;
+	}
+
+	ret = rzg2l_gpio_direction_input(gc, child);
+	if (ret)
+		return ret;
+
+	return gpiochip_irq_reqres(d);
+}
+
+static void rzg2l_gpio_irq_release_resources(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	unsigned int child = irqd_to_hwirq(d);
+
+	gpiochip_irq_relres(d);
+	rzg2l_gpio_free(gc, child);
+}
+
 static const struct irq_chip rzg2l_gpio_irqchip = {
 	.name = "rzg2l-gpio",
 	.irq_disable = rzg2l_gpio_irq_disable,
@@ -2368,8 +2401,9 @@ static const struct irq_chip rzg2l_gpio_irqchip = {
 	.irq_print_chip = rzg2l_gpio_irq_print_chip,
 	.irq_set_affinity = irq_chip_set_affinity_parent,
 	.irq_set_wake = rzg2l_gpio_irq_set_wake,
+	.irq_request_resources = rzg2l_gpio_irq_request_resources,
+	.irq_release_resources = rzg2l_gpio_irq_release_resources,
 	.flags = IRQCHIP_IMMUTABLE,
-	GPIOCHIP_IRQ_RESOURCE_HELPERS,
 };
 
 static int rzg2l_gpio_child_to_parent_hwirq(struct gpio_chip *gc,
@@ -2381,16 +2415,11 @@ static int rzg2l_gpio_child_to_parent_hwirq(struct gpio_chip *gc,
 	struct rzg2l_pinctrl *pctrl = gpiochip_get_data(gc);
 	unsigned long flags;
 	int gpioint, irq;
-	int ret;
 
 	gpioint = rzg2l_gpio_get_gpioint(child, pctrl);
 	if (gpioint < 0)
 		return gpioint;
 
-	ret = rzg2l_gpio_direction_input(gc, child);
-	if (ret)
-		return ret;
-
 	spin_lock_irqsave(&pctrl->bitmap_lock, flags);
 	irq = bitmap_find_free_region(pctrl->tint_slot, RZG2L_TINT_MAX_INTERRUPT, get_order(1));
 	spin_unlock_irqrestore(&pctrl->bitmap_lock, flags);
-- 
2.43.0