[PATCH v4] soc: fsl: qe: Add support of IRQ in QE GPIO

[Christophe Leroy]

In the QE, a few GPIOs are IRQ capable. Similarly to
commit 726bd223105c ("powerpc/8xx: Adding support of IRQ in MPC8xx
GPIO"), add IRQ support to QE GPIO.

Add property 'fsl,qe-gpio-irq-mask' similar to
'fsl,cpm1-gpio-irq-mask' that define which of the GPIOs have IRQs.

Here is an exemple for port B of mpc8323 which has IRQs for
GPIOs PB7, PB9, PB25 and PB27.

        qe_pio_b: gpio-controller@1418 {
                compatible = "fsl,mpc8323-qe-pario-bank";
                reg = <0x1418 0x18>;
                interrupts = <4 5 6 7>;
                interrupt-parent = <&qepic>;
                gpio-controller;
                #gpio-cells = <2>;
                fsl,qe-gpio-irq-mask = <0x01400050>;
        };

Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
v4: Using device_property_read_u32() instead of of_property_read_u32()
---
 drivers/soc/fsl/qe/gpio.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/soc/fsl/qe/gpio.c b/drivers/soc/fsl/qe/gpio.c
index 5bf073bbaac8..68bcd6048b1c 100644
--- a/drivers/soc/fsl/qe/gpio.c
+++ b/drivers/soc/fsl/qe/gpio.c
@@ -12,11 +12,13 @@
 #include <linux/spinlock.h>
 #include <linux/err.h>
 #include <linux/io.h>
+#include <linux/of_irq.h>
 #include <linux/gpio/consumer.h>
 #include <linux/gpio/driver.h>
 #include <linux/slab.h>
 #include <linux/export.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 
 #include <soc/fsl/qe/qe.h>
 
@@ -30,6 +32,8 @@ struct qe_gpio_chip {
 
        /* saved_regs used to restore dedicated functions */
        struct qe_pio_regs saved_regs;
+
+       int irq[32];
 };
 
 static void qe_gpio_save_regs(struct qe_gpio_chip *qe_gc)
@@ -133,6 +137,13 @@ static int qe_gpio_dir_out(struct gpio_chip *gc, unsigned 
int gpio, int val)
        return 0;
 }
 
+static int qe_gpio_to_irq(struct gpio_chip *gc, unsigned int gpio)
+{
+       struct qe_gpio_chip *qe_gc = gpiochip_get_data(gc);
+
+       return qe_gc->irq[gpio] ? : -ENXIO;
+}
+
 struct qe_pin {
        /*
         * The qe_gpio_chip name is unfortunate, we should change that to
@@ -293,6 +304,7 @@ static int qe_gpio_probe(struct platform_device *ofdev)
        struct device_node *np = dev->of_node;
        struct qe_gpio_chip *qe_gc;
        struct gpio_chip *gc;
+       u32 mask;
 
        qe_gc = devm_kzalloc(dev, sizeof(*qe_gc), GFP_KERNEL);
        if (!qe_gc)
@@ -300,6 +312,14 @@ static int qe_gpio_probe(struct platform_device *ofdev)
 
        spin_lock_init(&qe_gc->lock);
 
+       if (!device_property_read_u32(dev, "fsl,qe-gpio-irq-mask", &mask)) {
+               int i, j;
+
+               for (i = 0, j = 0; i < ARRAY_SIZE(qe_gc->irq); i++)
+                       if (mask & (1 << (31 - i)))
+                               qe_gc->irq[i] = irq_of_parse_and_map(np, j++);
+       }
+
        gc = &qe_gc->gc;
 
        gc->base = -1;
@@ -309,6 +329,7 @@ static int qe_gpio_probe(struct platform_device *ofdev)
        gc->get = qe_gpio_get;
        gc->set = qe_gpio_set;
        gc->set_multiple = qe_gpio_set_multiple;
+       gc->to_irq = qe_gpio_to_irq;
        gc->parent = dev;
        gc->owner = THIS_MODULE;
 
-- 
2.49.0