gpio/mxc: make irqs work for fsl,imx21-gpio devices

The chained handler was set for the platform device with id == 0.
When the gpio devices are instantiated by a device tree, all have id ==
-1 and so the handler was unset resulting in unusable gpio irqs on
i.MX21 and i.MX27 (when using oftree).

Acked-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c
index c337143b18f8..c89c4c1e668d 100644
--- a/drivers/gpio/gpio-mxc.c
+++ b/drivers/gpio/gpio-mxc.c
@@ -398,10 +398,12 @@ static int __devinit mxc_gpio_probe(struct platform_device *pdev)
         writel(~0, port->base + GPIO_ISR);
 
         if (mxc_gpio_hwtype == IMX21_GPIO) {
-                /* setup one handler for all GPIO interrupts */
-                if (pdev->id == 0)
-                        irq_set_chained_handler(port->irq,
-                                                mx2_gpio_irq_handler);
+                /*
+                 * Setup one handler for all GPIO interrupts. Actually setting
+                 * the handler is needed only once, but doing it for every port
+                 * is more robust and easier.
+                 */
+                irq_set_chained_handler(port->irq, mx2_gpio_irq_handler);
         } else {
                 /* setup one handler for each entry */
                 irq_set_chained_handler(port->irq, mx3_gpio_irq_handler);