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>

3 files changed, 126 insertions, 0 deletions

diff --git a/drivers/video/bridge/Kconfig b/drivers/video/bridge/Kconfig
new file mode 100644
index 0000000000..7ba6b17426
--- /dev/null
+++ b/drivers/video/bridge/Kconfig
@@ -0,0 +1,8 @@
+config VIDEO_BRIDGE
+	bool "Support video bridges"
+	depends on DM
+	help
+	  Some platforms use video bridges to convert from one output to
+	  another. For example, where the SoC only supports eDP and the LCD
+	  requires LVDS, an eDP->LVDS bridge chip can be used to provide the
+	  necessary conversion. This option enables support for these devices.
diff --git a/drivers/video/bridge/Makefile b/drivers/video/bridge/Makefile
new file mode 100644
index 0000000000..f4bf087a18
--- /dev/null
+++ b/drivers/video/bridge/Makefile
@@ -0,0 +1,7 @@
+#
+#  Copyright (C) 2015 Google, Inc
+#  Written by Simon Glass <sjg@chromium.org>
+#
+#  SPDX-License-Identifier:	GPL-2.0+
+
+obj-$(CONFIG_VIDEO_BRIDGE) += video-bridge-uclass.o
diff --git a/drivers/video/bridge/video-bridge-uclass.c b/drivers/video/bridge/video-bridge-uclass.c
new file mode 100644
index 0000000000..e1ea42816a
--- /dev/null
+++ b/drivers/video/bridge/video-bridge-uclass.c
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <video_bridge.h>
+
+int video_bridge_set_backlight(struct udevice *dev, int percent)
+{
+	struct video_bridge_ops *ops = video_bridge_get_ops(dev);
+
+	if (!ops->set_backlight)
+		return -ENOSYS;
+
+	return ops->set_backlight(dev, percent);
+}
+
+int video_bridge_attach(struct udevice *dev)
+{
+	struct video_bridge_ops *ops = video_bridge_get_ops(dev);
+
+	if (!ops->attach)
+		return -ENOSYS;
+
+	return ops->attach(dev);
+}
+
+int video_bridge_check_attached(struct udevice *dev)
+{
+	struct video_bridge_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct video_bridge_ops *ops = video_bridge_get_ops(dev);
+	int ret;
+
+	if (!ops->check_attached) {
+		ret = dm_gpio_get_value(&uc_priv->hotplug);
+
+		return ret > 0 ? 0 : ret == 0 ? -ENOTCONN : ret;
+	}
+
+	return ops->check_attached(dev);
+}
+
+static int video_bridge_pre_probe(struct udevice *dev)
+{
+	struct video_bridge_priv *uc_priv = dev_get_uclass_priv(dev);
+	int ret;
+
+	debug("%s\n", __func__);
+	ret = gpio_request_by_name(dev, "sleep-gpios", 0,
+				   &uc_priv->sleep, GPIOD_IS_OUT);
+	if (ret) {
+		debug("%s: Could not decode sleep-gpios (%d)\n", __func__, ret);
+		return ret;
+	}
+	ret = dm_gpio_set_pull(&uc_priv->sleep, GPIO_PULL_NONE);
+	if (ret) {
+		debug("%s: Could not set sleep pull value\n", __func__);
+		return ret;
+	}
+	ret = gpio_request_by_name(dev, "reset-gpios", 0, &uc_priv->reset,
+				   GPIOD_IS_OUT);
+	if (ret) {
+		debug("%s: Could not decode reset-gpios (%d)\n", __func__, ret);
+		return ret;
+	}
+	ret = dm_gpio_set_pull(&uc_priv->reset, GPIO_PULL_NONE);
+	if (ret) {
+		debug("%s: Could not set reset pull value\n", __func__);
+		return ret;
+	}
+	ret = gpio_request_by_name(dev, "hotplug-gpios", 0, &uc_priv->hotplug,
+				   GPIOD_IS_IN);
+	if (ret && ret != -ENOENT) {
+		debug("%s: Could not decode hotplug (%d)\n", __func__, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+int video_bridge_set_active(struct udevice *dev, bool active)
+{
+	struct video_bridge_priv *uc_priv = dev_get_uclass_priv(dev);
+	int ret;
+
+	debug("%s: %d\n", __func__, active);
+	ret = dm_gpio_set_value(&uc_priv->sleep, !active);
+	if (ret)
+		return ret;
+	if (active) {
+		ret = dm_gpio_set_value(&uc_priv->reset, true);
+		if (ret)
+			return ret;
+		udelay(10);
+		ret = dm_gpio_set_value(&uc_priv->reset, false);
+	}
+
+	return ret;
+}
+
+UCLASS_DRIVER(video_bridge) = {
+	.id		= UCLASS_VIDEO_BRIDGE,
+	.name		= "video_bridge",
+	.per_device_auto_alloc_size	= sizeof(struct video_bridge_priv),
+	.pre_probe	= video_bridge_pre_probe,
+};