gpio: rcar: Prevent module clock disable when wake-up is enabled

When the GPIO module is needed for wake-up, it's module clock must not
be disabled. Hence implement irq_chip.irq_set_wake(), which
increments/decrements the clock's enable_count when needed, and forwards
the wake-up state to the upstream interrupt controller.

This fixes wake-up from s2ram using gpio-keys when using a PM Domain to
manage the module clock.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 31 insertions, 2 deletions

diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c
index d96166ca1b42..fd3977465948 100644
--- a/drivers/gpio/gpio-rcar.c
+++ b/drivers/gpio/gpio-rcar.c
@@ -14,6 +14,7 @@
  * GNU General Public License for more details.
  */
 
+#include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/gpio.h>
 #include <linux/init.h>
@@ -37,6 +38,8 @@ struct gpio_rcar_priv {
         struct platform_device *pdev;
         struct gpio_chip gpio_chip;
         struct irq_chip irq_chip;
+        unsigned int irq_parent;
+        struct clk *clk;
 };
 
 #define IOINTSEL 0x00   /* General IO/Interrupt Switching Register */
@@ -169,6 +172,25 @@ static int gpio_rcar_irq_set_type(struct irq_data *d, unsigned int type)
         return 0;
 }
 
+static int gpio_rcar_irq_set_wake(struct irq_data *d, unsigned int on)
+{
+        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+        struct gpio_rcar_priv *p = container_of(gc, struct gpio_rcar_priv,
+                                                gpio_chip);
+
+        irq_set_irq_wake(p->irq_parent, on);
+
+        if (!p->clk)
+                return 0;
+
+        if (on)
+                clk_enable(p->clk);
+        else
+                clk_disable(p->clk);
+
+        return 0;
+}
+
 static irqreturn_t gpio_rcar_irq_handler(int irq, void *dev_id)
 {
         struct gpio_rcar_priv *p = dev_id;
@@ -367,6 +389,12 @@ static int gpio_rcar_probe(struct platform_device *pdev)
 
         platform_set_drvdata(pdev, p);
 
+        p->clk = devm_clk_get(dev, NULL);
+        if (IS_ERR(p->clk)) {
+                dev_warn(dev, "unable to get clock\n");
+                p->clk = NULL;
+        }
+
         pm_runtime_enable(dev);
         pm_runtime_get_sync(dev);
 
@@ -404,8 +432,8 @@ static int gpio_rcar_probe(struct platform_device *pdev)
         irq_chip->irq_mask = gpio_rcar_irq_disable;
         irq_chip->irq_unmask = gpio_rcar_irq_enable;
         irq_chip->irq_set_type = gpio_rcar_irq_set_type;
-        irq_chip->flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_SET_TYPE_MASKED
-                         | IRQCHIP_MASK_ON_SUSPEND;
+        irq_chip->irq_set_wake = gpio_rcar_irq_set_wake;
+        irq_chip->flags = IRQCHIP_SET_TYPE_MASKED | IRQCHIP_MASK_ON_SUSPEND;
 
         ret = gpiochip_add(gpio_chip);
         if (ret) {
@@ -420,6 +448,7 @@ static int gpio_rcar_probe(struct platform_device *pdev)
                 goto err1;
         }
 
+        p->irq_parent = irq->start;
         if (devm_request_irq(dev, irq->start, gpio_rcar_irq_handler,
                              IRQF_SHARED, name, p)) {
                 dev_err(dev, "failed to request IRQ\n");