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dm: backlight: Add a driver for GPIO backlight

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Add a driver for GPIO backlights.
It understands the standard device tree binding.
It can be used with simple-panel when PWM is not necessary.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
This commit is contained in:
Patrick Delaunay 2017-08-03 12:36:07 +02:00 committed by Anatolij Gustschin
parent 08a43cfbc2
commit 5b6a6a91c8
3 changed files with 85 additions and 0 deletions
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10
drivers/video/Kconfig
View file

@ -25,6 +25,16 @@ config BACKLIGHT_PWM
it understands the standard device tree
(leds/backlight/pwm-backlight.txt)
config BACKLIGHT_GPIO
bool "Generic GPIO based Backlight Driver"
depends on DM_VIDEO
help
If you have a LCD backlight adjustable by GPIO, say Y to enable
this driver.
This driver can be used with "simple-panel" and
it understands the standard device tree
(leds/backlight/gpio-backlight.txt)
config VIDEO_BPP8
bool "Support 8-bit-per-pixel displays"
depends on DM_VIDEO

1
drivers/video/Makefile
View file

@ -12,6 +12,7 @@ obj-$(CONFIG_DM_VIDEO) += panel-uclass.o simple_panel.o
obj-$(CONFIG_DM_VIDEO) += video-uclass.o vidconsole-uclass.o
obj-$(CONFIG_DM_VIDEO) += video_bmp.o
obj-$(CONFIG_BACKLIGHT_PWM) += pwm_backlight.o
obj-$(CONFIG_BACKLIGHT_GPIO) += backlight_gpio.o
obj-$(CONFIG_CONSOLE_NORMAL) += console_normal.o
obj-$(CONFIG_CONSOLE_ROTATION) += console_rotate.o
obj-$(CONFIG_CONSOLE_TRUETYPE) += console_truetype.o fonts/

74
drivers/video/backlight_gpio.c Normal file
View file

@ -0,0 +1,74 @@
/*
* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
* Author: Patrick Delaunay <patrick.delaunay@st.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <backlight.h>
#include <asm/gpio.h>
DECLARE_GLOBAL_DATA_PTR;
struct gpio_backlight_priv {
struct gpio_desc gpio;
bool def_value;
};
static int gpio_backlight_enable(struct udevice *dev)
{
struct gpio_backlight_priv *priv = dev_get_priv(dev);
dm_gpio_set_value(&priv->gpio, 1);
return 0;
}
static int gpio_backlight_ofdata_to_platdata(struct udevice *dev)
{
struct gpio_backlight_priv *priv = dev_get_priv(dev);
int ret;
ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio,
GPIOD_IS_OUT);
if (ret) {
debug("%s: Warning: cannot get GPIO: ret=%d\n",
__func__, ret);
return ret;
}
priv->def_value = dev_read_bool(dev, "default-on");
return 0;
}
static int gpio_backlight_probe(struct udevice *dev)
{
struct gpio_backlight_priv *priv = dev_get_priv(dev);
if (priv->def_value)
gpio_backlight_enable(dev);
return 0;
}
static const struct backlight_ops gpio_backlight_ops = {
.enable = gpio_backlight_enable,
};
static const struct udevice_id gpio_backlight_ids[] = {
{ .compatible = "gpio-backlight" },
{ }
};
U_BOOT_DRIVER(gpio_backlight) = {
.name = "gpio_backlight",
.id = UCLASS_PANEL_BACKLIGHT,
.of_match = gpio_backlight_ids,
.ops = &gpio_backlight_ops,
.ofdata_to_platdata = gpio_backlight_ofdata_to_platdata,
.probe = gpio_backlight_probe,
.priv_auto_alloc_size = sizeof(struct gpio_backlight_priv),
};