dm: video: Add support for video bridges

A video bridge typically converts video from one format to another, e.g.
DisplayPort to LVDS. Add driver model support for these with a simple
interface to control activation and backlight. The uclass supports GPIO
control of power and reset lines.

Signed-off-by: Simon Glass <sjg@chromium.org>

2 files changed, 93 insertions, 0 deletions

diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 777b101842..c744044bb8 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -57,6 +57,7 @@ enum uclass_id {
 	UCLASS_USB,		/* USB bus */
 	UCLASS_USB_DEV_GENERIC,	/* USB generic device */
 	UCLASS_USB_HUB,		/* USB hub */
+	UCLASS_VIDEO_BRIDGE,	/* Video bridge, e.g. DisplayPort to LVDS */
 
 	UCLASS_COUNT,
 	UCLASS_INVALID = -1,
diff --git a/include/video_bridge.h b/include/video_bridge.h
new file mode 100644
index 0000000000..c7b8681849
--- /dev/null
+++ b/include/video_bridge.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __VIDEO_BRIDGE
+#define __VIDEO_BRIDGE
+
+#include <asm/gpio.h>
+
+/**
+ * struct video_bridge_priv - uclass information for video bridges
+ *
+ * @sleep:	GPIO to assert to power down the bridge
+ * @reset:	GPIO to assert to reset the bridge
+ * @hotplug:	Optional GPIO to check if bridge is connected
+ */
+struct video_bridge_priv {
+	struct gpio_desc sleep;
+	struct gpio_desc reset;
+	struct gpio_desc hotplug;
+};
+
+/**
+ * Operations for video bridges
+ */
+struct video_bridge_ops {
+	/**
+	 * attach() - attach a video bridge
+	 *
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*attach)(struct udevice *dev);
+
+	/**
+	 * check_attached() - check if a bridge is correctly attached
+	 *
+	 * This method is optional - if not provided then the hotplug GPIO
+	 * will be checked instead.
+	 *
+	 * @dev:	Device to check
+	 * @return 0 if attached, -EENOTCONN if not, or other -ve error
+	 */
+	int (*check_attached)(struct udevice *dev);
+
+	/**
+	 * set_backlight() - Set the backlight brightness
+	 *
+	 * @dev:	device to adjust
+	 * @percent:	brightness percentage (0=off, 100=full brightness)
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*set_backlight)(struct udevice *dev, int percent);
+};
+
+#define video_bridge_get_ops(dev) \
+		((struct video_bridge_ops *)(dev)->driver->ops)
+
+/**
+ * video_bridge_attach() - attach a video bridge
+ *
+ * @return 0 if OK, -ve on error
+ */
+int video_bridge_attach(struct udevice *dev);
+
+/**
+ * video_bridge_set_backlight() - Set the backlight brightness
+ *
+ * @percent:	brightness percentage (0=off, 100=full brightness)
+ * @return 0 if OK, -ve on error
+ */
+int video_bridge_set_backlight(struct udevice *dev, int percent);
+
+/**
+ * video_bridge_set_active() - take the bridge in/out of reset/powerdown
+ *
+ * @dev:	Device to adjust
+ * @active:	true to power up and reset, false to power down
+ */
+int video_bridge_set_active(struct udevice *dev, bool active);
+
+/**
+ * check_attached() - check if a bridge is correctly attached
+ *
+ * @dev:	Device to check
+ * @return 0 if attached, -EENOTCONN if not, or other -ve error
+ */
+int video_bridge_check_attached(struct udevice *dev);
+
+#endif