[PATCH v5 02/11] gpio: allow gpio_to_irq to use OF variants for gpiochips

[Lina Iyer <ilina@codeaurora.org>]

The chip may define additional information in the DT that may be useful
for translating and allocting a linux interrupt for the GPIO. When
drivers do not specify a .to_irq function, the gpiolib defaults to
gpiochip_to_irq() function. The defalt function uses creates an IRQ
without referencing the OF definition of the gpiochip. Let's add this
OF support to the default gpiochip_to_irq function.

When requesting an interrupt for the GPIO, let's stick to IRQ_TYPE_NONE
for the trigger type, for we don't have the information what trigger
type the driver may set when requesting the IRQ.

Signed-off-by: Lina Iyer <ilina@codeaurora.org>
---
 drivers/gpio/gpiolib.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 4a9a6d4afe6e..77317435e2b2 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1825,6 +1825,19 @@ EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
 
 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
 {
+#ifdef CONFIG_OF_GPIO
+	struct irq_fwspec fwspec;
+
+	if (chip->of_node) {
+		fwspec.fwnode = of_node_to_fwnode(chip->of_node);
+		fwspec.param[0] = offset;
+		fwspec.param[1] = IRQ_TYPE_NONE;
+		fwspec.param_count = 2;
+
+		return irq_create_fwspec_mapping(&fwspec);
+	}
+#endif
+
 	if (!gpiochip_irqchip_irq_valid(chip, offset))
 		return -ENXIO;
 
-- 
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