dm: backlight: Add a backlight uclass

LCD panels normally have a backlight which can be controlled to illuminate
the LCD contents. Add a uclass to support this. Initially it only has a
method to enable the backlight.

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

diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index ee04629..fa90721 100644 (file)
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -7,6 +7,7 @@
 
 ifdef CONFIG_DM
 obj-$(CONFIG_DISPLAY_PORT) += dp-uclass.o
+obj-$(CONFIG_DM_VIDEO) += backlight-uclass.o
 obj-$(CONFIG_DM_VIDEO) += video-uclass.o vidconsole-uclass.o console_normal.o
 obj-$(CONFIG_DM_VIDEO) += video_bmp.o
 obj-$(CONFIG_VIDEO_ROTATION) += console_rotate.o

diff --git a/drivers/video/backlight-uclass.c b/drivers/video/backlight-uclass.c
new file mode 100644 (file)
index 0000000..0238289
--- /dev/null
+++ b/drivers/video/backlight-uclass.c
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2016 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <backlight.h>
+
+int backlight_enable(struct udevice *dev)
+{
+       const struct backlight_ops *ops = backlight_get_ops(dev);
+
+       if (!ops->enable)
+               return -ENOSYS;
+
+       return ops->enable(dev);
+}
+
+UCLASS_DRIVER(backlight) = {
+       .id             = UCLASS_PANEL_BACKLIGHT,
+       .name           = "backlight",
+};

diff --git a/include/backlight.h b/include/backlight.h
new file mode 100644 (file)
index 0000000..90e1d98
--- /dev/null
+++ b/include/backlight.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2016 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#ifndef _BACKLIGHT_H
+#define _BACKLIGHT_H
+
+struct backlight_ops {
+       /**
+        * enable() - Enable a backlight
+        *
+        * @dev:        Backlight device to enable
+        * @return 0 if OK, -ve on error
+        */
+       int (*enable)(struct udevice *dev);
+};
+
+#define backlight_get_ops(dev) ((struct backlight_ops *)(dev)->driver->ops)
+
+/**
+ * backlight_enable() - Enable a backlight
+ *
+ * @dev:       Backlight device to enable
+ * @return 0 if OK, -ve on error
+ */
+int backlight_enable(struct udevice *dev);
+
+#endif

diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 8f0381d..5421981 100644 (file)
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -45,6 +45,7 @@ enum uclass_id {
        UCLASS_MMC,             /* SD / MMC card or chip */
        UCLASS_MOD_EXP,         /* RSA Mod Exp device */
        UCLASS_MTD,             /* Memory Technology Device (MTD) device */
+       UCLASS_PANEL_BACKLIGHT, /* Backlight controller for panel */
        UCLASS_PCH,             /* x86 platform controller hub */
        UCLASS_PCI,             /* PCI bus */
        UCLASS_PCI_GENERIC,     /* Generic PCI bus device */