dm: input: add implementation of driver model key uclass

Change-Id: I379b694dfaee14ed23cc7abfa05aff77933bb725
Signed-off-by: Joseph Chen <chenjh@rock-chips.com>

drivers/input/Kconfig

@@ -7,6 +7,12 @@ config DM_KEYBOARD
 	  includes methods to start/stop the device, check for available
 	  input and update LEDs if the keyboard has them.
 
+config DM_KEY
+	bool "Enable driver model key support"
+	depends on DM
+	help
+	  This adds a simple uclass for key.
+
 config CROS_EC_KEYB
 	bool "Enable Chrome OS EC keyboard support"
 	help

drivers/input/Makefile

@@ -6,6 +6,7 @@
 #
 
 obj-$(CONFIG_DM_KEYBOARD) += keyboard-uclass.o
+obj-$(CONFIG_DM_KEY) += key-uclass.o
 
 obj-$(CONFIG_I8042_KEYB) += i8042.o
 obj-$(CONFIG_TEGRA_KEYBOARD) += tegra-kbc.o

drivers/input/key-uclass.c

@@ -0,0 +1,23 @@
+/*
+ * (C) Copyright 2017 Rockchip Electronics Co., Ltd
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <dm.h>
+#include <key.h>
+
+int key_read(struct udevice *dev)
+{
+	const struct dm_key_ops *ops = dev_get_driver_ops(dev);
+
+	if (!ops || !ops->read)
+		return -ENOSYS;
+
+	return ops->read(dev);
+}
+
+UCLASS_DRIVER(key) = {
+	.id		= UCLASS_KEY,
+	.name		= "key",
+};

include/dm/uclass-id.h

@@ -90,6 +90,7 @@ enum uclass_id {
 	UCLASS_VIDEO_CONSOLE,	/* Text console driver for video device */
 	UCLASS_WDT,		/* Watchdot Timer driver */
 	UCLASS_FG,
+	UCLASS_KEY,
 
 	UCLASS_COUNT,
 	UCLASS_INVALID = -1,

include/key.h

@@ -0,0 +1,22 @@
+/*
+ * (C) Copyright 2017 Rockchip Electronics Co., Ltd
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#ifndef _KEY_H_
+#define _KEY_H_
+
+enum key_state {
+	KEY_PRESS_NONE,
+	KEY_PRESS_UP,
+	KEY_PRESS_DOWN,
+};
+
+struct dm_key_ops {
+	int (*read)(struct udevice *dev);
+};
+
+int key_read(struct udevice *dev);
+
+#endif