sh-pfc: Support GPIO to IRQ mapping specified IRQ resources

On non-DT platforms IRQ controllers associated with the GPIOs have a
fixed IRQ base value known at compile time. The sh-pfc driver translates
GPIO number to IRQ numbers using a hardcoded table. This mechanism
breaks on DT platforms, as the IRQ base values are dynamic in that case.

Fix this by specifying IRQs associated with GPIOs in IRQ resources,
populated automatically from the device tree. When IRQ resources are
specified the driver requires one IRQ resource per GPIO able to generate
an interrupt, and uses the translation table to compute the IRQ resource
offset instead of the IRQ number.

Cc: devicetree@vger.kernel.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/pinctrl/sh-pfc/gpio.c b/drivers/pinctrl/sh-pfc/gpio.c
index 6a21349fb116..63480815e1af 100644
--- a/drivers/pinctrl/sh-pfc/gpio.c
+++ b/drivers/pinctrl/sh-pfc/gpio.c
@@ -211,11 +211,17 @@ static int gpio_pin_to_irq(struct gpio_chip *gc, unsigned offset)
 
 		for (k = 0; gpios[k] >= 0; k++) {
 			if (gpios[k] == offset)
-				return pfc->info->gpio_irq[i].irq;
+				goto found;
 		}
 	}
 
 	return -ENOSYS;
+
+found:
+	if (pfc->num_irqs)
+		return pfc->irqs[i];
+	else
+		return pfc->info->gpio_irq[i].irq;
 }
 
 static int gpio_pin_setup(struct sh_pfc_chip *chip)
@@ -357,6 +363,12 @@ int sh_pfc_register_gpiochip(struct sh_pfc *pfc)
 	if (i == pfc->num_windows)
 		return 0;
 
+	/* If we have IRQ resources make sure their number is correct. */
+	if (pfc->num_irqs && pfc->num_irqs != pfc->info->gpio_irq_size) {
+		dev_err(pfc->dev, "invalid number of IRQ resources\n");
+		return -EINVAL;
+	}
+
 	/* Register the real GPIOs chip. */
 	chip = sh_pfc_add_gpiochip(pfc, gpio_pin_setup, &pfc->windows[i]);
 	if (IS_ERR(chip))