Input: gpio_keys - add device tree support for interrupt only keys

This features already exists for board config setups. Add support for
device tree based systems.

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

2 files changed, 29 insertions, 15 deletions

diff --git a/Documentation/devicetree/bindings/input/gpio-keys.txt b/Documentation/devicetree/bindings/input/gpio-keys.txt
index 5c2c02140a62..a4a38fcf2ed6 100644
--- a/Documentation/devicetree/bindings/input/gpio-keys.txt
+++ b/Documentation/devicetree/bindings/input/gpio-keys.txt
@@ -10,10 +10,13 @@ Optional properties:
 Each button (key) is represented as a sub-node of "gpio-keys":
 Subnode properties:
 
-        - gpios: OF device-tree gpio specification.
         - label: Descriptive name of the key.
         - linux,code: Keycode to emit.
 
+Required mutual exclusive subnode-properties:
+        - gpios: OF device-tree gpio specification.
+        - interrupts: the interrupt line for that input
+
 Optional subnode-properties:
         - linux,input-type: Specify event type this button/key generates.
           If not specified defaults to <1> == EV_KEY.
@@ -33,4 +36,9 @@ Example nodes:
                                 linux,code = <103>;
                                 gpios = <&gpio1 0 1>;
                         };
+                        button@22 {
+                                label = "GPIO Key DOWN";
+                                linux,code = <108>;
+                                interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;
+                        };
                         ...
diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index 8c98e97f8e41..ce0d9090bbe9 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -29,6 +29,7 @@
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/of_gpio.h>
+#include <linux/of_irq.h>
 #include <linux/spinlock.h>
 
 struct gpio_button_data {
@@ -617,28 +618,33 @@ gpio_keys_get_devtree_pdata(struct device *dev)
 
         i = 0;
         for_each_child_of_node(node, pp) {
-                int gpio;
+                int gpio = -1;
+                int irq;
                 enum of_gpio_flags flags;
 
                 if (!of_find_property(pp, "gpios", NULL)) {
-                        pdata->nbuttons--;
-                        dev_warn(dev, "Found button without gpios\n");
-                        continue;
-                }
-
-                gpio = of_get_gpio_flags(pp, 0, &flags);
-                if (gpio < 0) {
-                        error = gpio;
-                        if (error != -EPROBE_DEFER)
-                                dev_err(dev,
-                                        "Failed to get gpio flags, error: %d\n",
-                                        error);
-                        return ERR_PTR(error);
+                        irq = irq_of_parse_and_map(pp, 0);
+                        if (irq == 0) {
+                                pdata->nbuttons--;
+                                dev_warn(dev, "Found button without gpios or irqs\n");
+                                continue;
+                        }
+                } else {
+                        gpio = of_get_gpio_flags(pp, 0, &flags);
+                        if (gpio < 0) {
+                                error = gpio;
+                                if (error != -EPROBE_DEFER)
+                                        dev_err(dev,
+                                                "Failed to get gpio flags, error: %d\n",
+                                                error);
+                                return ERR_PTR(error);
+                        }
                 }
 
                 button = &pdata->buttons[i++];
 
                 button->gpio = gpio;
+                button->irq = irq;
                 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
 
                 if (of_property_read_u32(pp, "linux,code", &button->code)) {