dm: button: add support for linux_code in button-gpio.c driver

Linux event code must be used in input devices, using buttons.

Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/sandbox/dts/test.dts

@@ -172,11 +172,13 @@
 		btn1 {
 			gpios = <&gpio_a 3 0>;
 			label = "button1";
+			linux,code = <BTN_1>;
 		};
 
 		btn2 {
 			gpios = <&gpio_a 4 0>;
 			label = "button2";
+			linux,code = <BTN_2>;
 		};
 	};
 

drivers/button/button-gpio.c

@@ -13,6 +13,7 @@
 
 struct button_gpio_priv {
 	struct gpio_desc gpio;
+	int linux_code;
 };
 
 static enum button_state_t button_gpio_get_state(struct udevice *dev)
@@ -29,6 +30,17 @@ static enum button_state_t button_gpio_get_state(struct udevice *dev)
 	return ret ? BUTTON_ON : BUTTON_OFF;
 }
 
+static int button_gpio_get_code(struct udevice *dev)
+{
+	struct button_gpio_priv *priv = dev_get_priv(dev);
+	int code = priv->linux_code;
+
+	if (!code)
+		return -ENODATA;
+
+	return code;
+}
+
 static int button_gpio_probe(struct udevice *dev)
 {
 	struct button_uc_plat *uc_plat = dev_get_uclass_plat(dev);
@@ -43,7 +55,9 @@ static int button_gpio_probe(struct udevice *dev)
 	if (ret)
 		return ret;
 
-	return 0;
+	ret = dev_read_u32(dev, "linux,code", &priv->linux_code);
+
+	return ret;
 }
 
 static int button_gpio_remove(struct udevice *dev)
@@ -92,6 +106,7 @@ static int button_gpio_bind(struct udevice *parent)
 
 static const struct button_ops button_gpio_ops = {
 	.get_state	= button_gpio_get_state,
+	.get_code	= button_gpio_get_code,
 };
 
 static const struct udevice_id button_gpio_ids[] = {

drivers/button/button-uclass.c

@@ -38,6 +38,16 @@ enum button_state_t button_get_state(struct udevice *dev)
 	return ops->get_state(dev);
 }
 
+int button_get_code(struct udevice *dev)
+{
+	struct button_ops *ops = button_get_ops(dev);
+
+	if (!ops->get_code)
+		return -ENOSYS;
+
+	return ops->get_code(dev);
+}
+
 UCLASS_DRIVER(button) = {
 	.id		= UCLASS_BUTTON,
 	.name		= "button",

include/button.h

@@ -37,6 +37,14 @@ struct button_ops {
 	 * @return button state button_state_t, or -ve on error
 	 */
 	enum button_state_t (*get_state)(struct udevice *dev);
+
+	/**
+	 * get_code() - get linux event code of a button
+	 *
+	 * @dev:	button device to change
+	 * @return button code, or -ENODATA on error
+	 */
+	int (*get_code)(struct udevice *dev);
 };
 
 #define button_get_ops(dev)	((struct button_ops *)(dev)->driver->ops)
@@ -58,4 +66,12 @@ int button_get_by_label(const char *label, struct udevice **devp);
  */
 enum button_state_t button_get_state(struct udevice *dev);
 
+/**
+ * button_get_code() - get linux event code of a button
+ *
+ * @dev:	button device to change
+ * @return button code, or -ve on error
+ */
+int button_get_code(struct udevice *dev);
+
 #endif

test/dm/button.c

@@ -13,6 +13,7 @@
 #include <power/sandbox_pmic.h>
 #include <asm/gpio.h>
 #include <dm/test.h>
+#include <dt-bindings/input/input.h>
 #include <test/ut.h>
 
 /* Base test of the button uclass */
@@ -85,6 +86,18 @@ static int dm_test_button_label(struct unit_test_state *uts)
 }
 DM_TEST(dm_test_button_label, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
 
+/* Test button has linux,code */
+static int dm_test_button_linux_code(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+
+	ut_assertok(uclass_get_device(UCLASS_BUTTON, 1, &dev));
+	ut_asserteq(BTN_1, button_get_code(dev));
+
+	return 0;
+}
+DM_TEST(dm_test_button_linux_code, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
+
 /* Test adc-keys driver */
 static int dm_test_button_keys_adc(struct unit_test_state *uts)
 {