[U-Boot] [PATCH 31/55] dm: video: Add support for video bridges
Simon Glass
sjg at chromium.org
Fri Jul 3 02:16:08 CEST 2015
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 at chromium.org>
---
drivers/video/Kconfig | 2 +
drivers/video/Makefile | 2 +
drivers/video/bridge/Kconfig | 8 +++
drivers/video/bridge/Makefile | 7 ++
drivers/video/bridge/video-bridge-uclass.c | 111 +++++++++++++++++++++++++++++
include/dm/uclass-id.h | 1 +
include/video_bridge.h | 92 ++++++++++++++++++++++++
7 files changed, 223 insertions(+)
create mode 100644 drivers/video/bridge/Kconfig
create mode 100644 drivers/video/bridge/Makefile
create mode 100644 drivers/video/bridge/video-bridge-uclass.c
create mode 100644 include/video_bridge.h
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 9ae23e8..3244cd7 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -240,3 +240,5 @@ config VIDEO_TEGRA124
HDMI. At present only eDP is supported by U-Boot. This option
enables this support which can be used on devices which
have an eDP display connected.
+
+source "drivers/video/bridge/Kconfig"
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 2ead7f1..599fe83 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -54,3 +54,5 @@ obj-$(CONFIG_AM335X_LCD) += am335x-fb.o
obj-$(CONFIG_VIDEO_PARADE) += parade.o
obj-${CONFIG_VIDEO_TEGRA124} += tegra124/
+
+obj-y += bridge/
diff --git a/drivers/video/bridge/Kconfig b/drivers/video/bridge/Kconfig
new file mode 100644
index 0000000..7ba6b17
--- /dev/null
+++ b/drivers/video/bridge/Kconfig
@@ -0,0 +1,8 @@
+config VIDEO_BRIDGE
+ bool "Support video bridges"
+ depends on DM
+ help
+ Some platforms use video bridges to convert from one output to
+ another. For example, where the SoC only supports eDP and the LCD
+ requires LVDS, an eDP->LVDS bridge chip can be used to provide the
+ necessary conversion. This option enables support for these devices.
diff --git a/drivers/video/bridge/Makefile b/drivers/video/bridge/Makefile
new file mode 100644
index 0000000..f4bf087
--- /dev/null
+++ b/drivers/video/bridge/Makefile
@@ -0,0 +1,7 @@
+#
+# Copyright (C) 2015 Google, Inc
+# Written by Simon Glass <sjg at chromium.org>
+#
+# SPDX-License-Identifier: GPL-2.0+
+
+obj-$(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 0000000..e1ea428
--- /dev/null
+++ b/drivers/video/bridge/video-bridge-uclass.c
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2015 Google, Inc
+ * Written by Simon Glass <sjg at 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,
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index e2c3480..c1a6594 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -58,6 +58,7 @@ 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 0000000..c7b8681
--- /dev/null
+++ b/include/video_bridge.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2015 Google, Inc
+ * Written by Simon Glass <sjg at 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
--
2.4.3.573.g4eafbef
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