WSL2-Linux-Kernel/drivers/video/backlight/gpio_backlight.c

171 строка
4.2 KiB
C
Исходник Обычный вид История

/*
* gpio_backlight.c - Simple GPIO-controlled backlight
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/fb.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/platform_data/gpio_backlight.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
struct gpio_backlight {
struct device *dev;
struct device *fbdev;
int gpio;
int active;
int def_value;
};
static int gpio_backlight_update_status(struct backlight_device *bl)
{
struct gpio_backlight *gbl = bl_get_data(bl);
int brightness = bl->props.brightness;
if (bl->props.power != FB_BLANK_UNBLANK ||
bl->props.fb_blank != FB_BLANK_UNBLANK ||
bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
brightness = 0;
backlight: gpio-backlight: Fix warning when the GPIO is on a I2C chip If the GPIO for the backlight is on an I2C chip, we currently get nasty warnings like this during the boot: WARNING: CPU: 0 PID: 6 at drivers/gpio/gpiolib.c:2364 gpiod_set_raw_value+0x40/0x4c() Modules linked in: CPU: 0 PID: 6 Comm: kworker/u2:0 Not tainted 3.15.0-rc4-12393-gcde9f4e #400 Workqueue: deferwq deferred_probe_work_func [<c0014cbc>] (unwind_backtrace) from [<c001191c>] (show_stack+0x10/0x14) [<c001191c>] (show_stack) from [<c0566ae0>] (dump_stack+0x80/0x9c) [<c0566ae0>] (dump_stack) from [<c003f61c>] (warn_slowpath_common+0x68/0x8c) [<c003f61c>] (warn_slowpath_common) from [<c003f65c>] (warn_slowpath_null+0x1c/0x24) [<c003f65c>] (warn_slowpath_null) from [<c02f7e10>] (gpiod_set_raw_value+0x40/0x4c) [<c02f7e10>] (gpiod_set_raw_value) from [<c0308fbc>] (gpio_backlight_update_status+0x4c/0x74) [<c0308fbc>] (gpio_backlight_update_status) from [<c030914c>] (gpio_backlight_probe+0x168/0x254) [<c030914c>] (gpio_backlight_probe) from [<c0378fa8>] (platform_drv_probe+0x18/0x48) [<c0378fa8>] (platform_drv_probe) from [<c0377c40>] (driver_probe_device+0x10c/0x238) [<c0377c40>] (driver_probe_device) from [<c0376330>] (bus_for_each_drv+0x44/0x8c) [<c0376330>] (bus_for_each_drv) from [<c0377afc>] (device_attach+0x74/0x8c) [<c0377afc>] (device_attach) from [<c03771c4>] (bus_probe_device+0x88/0xb0) [<c03771c4>] (bus_probe_device) from [<c03775c8>] (deferred_probe_work_func+0x64/0x94) [<c03775c8>] (deferred_probe_work_func) from [<c00572e8>] (process_one_work+0x1b4/0x4bc) [<c00572e8>] (process_one_work) from [<c00579d0>] (worker_thread+0x11c/0x398) [<c00579d0>] (worker_thread) from [<c005dfd8>] (kthread+0xc8/0xe4) [<c005dfd8>] (kthread) from [<c000e768>] (ret_from_fork+0x14/0x2c) Fix this by using gpio_set_value_cansleep() as suggested in drivers/gpio/gpiolib.c:2364. This is what the other backlight drivers are also doing. Signed-off-by: Tony Lindgren <tony@atomide.com> Acked-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-05-09 05:24:55 +04:00
gpio_set_value_cansleep(gbl->gpio,
brightness ? gbl->active : !gbl->active);
return 0;
}
static int gpio_backlight_check_fb(struct backlight_device *bl,
struct fb_info *info)
{
struct gpio_backlight *gbl = bl_get_data(bl);
return gbl->fbdev == NULL || gbl->fbdev == info->dev;
}
static const struct backlight_ops gpio_backlight_ops = {
.options = BL_CORE_SUSPENDRESUME,
.update_status = gpio_backlight_update_status,
.check_fb = gpio_backlight_check_fb,
};
static int gpio_backlight_probe_dt(struct platform_device *pdev,
struct gpio_backlight *gbl)
{
struct device_node *np = pdev->dev.of_node;
enum of_gpio_flags gpio_flags;
gbl->gpio = of_get_gpio_flags(np, 0, &gpio_flags);
if (!gpio_is_valid(gbl->gpio)) {
if (gbl->gpio != -EPROBE_DEFER) {
dev_err(&pdev->dev,
"Error: The gpios parameter is missing or invalid.\n");
}
return gbl->gpio;
}
gbl->active = (gpio_flags & OF_GPIO_ACTIVE_LOW) ? 0 : 1;
gbl->def_value = of_property_read_bool(np, "default-on");
return 0;
}
static int gpio_backlight_probe(struct platform_device *pdev)
{
struct gpio_backlight_platform_data *pdata =
dev_get_platdata(&pdev->dev);
struct backlight_properties props;
struct backlight_device *bl;
struct gpio_backlight *gbl;
struct device_node *np = pdev->dev.of_node;
unsigned long flags = GPIOF_DIR_OUT;
int ret;
if (!pdata && !np) {
dev_err(&pdev->dev,
"failed to find platform data or device tree node.\n");
return -ENODEV;
}
gbl = devm_kzalloc(&pdev->dev, sizeof(*gbl), GFP_KERNEL);
if (gbl == NULL)
return -ENOMEM;
gbl->dev = &pdev->dev;
if (np) {
ret = gpio_backlight_probe_dt(pdev, gbl);
if (ret)
return ret;
} else {
gbl->fbdev = pdata->fbdev;
gbl->gpio = pdata->gpio;
gbl->active = pdata->active_low ? 0 : 1;
gbl->def_value = pdata->def_value;
}
if (gbl->active)
flags |= gbl->def_value ? GPIOF_INIT_HIGH : GPIOF_INIT_LOW;
else
flags |= gbl->def_value ? GPIOF_INIT_LOW : GPIOF_INIT_HIGH;
ret = devm_gpio_request_one(gbl->dev, gbl->gpio, flags,
pdata ? pdata->name : "backlight");
if (ret < 0) {
dev_err(&pdev->dev, "unable to request GPIO\n");
return ret;
}
memset(&props, 0, sizeof(props));
props.type = BACKLIGHT_RAW;
props.max_brightness = 1;
bl = devm_backlight_device_register(&pdev->dev, dev_name(&pdev->dev),
&pdev->dev, gbl, &gpio_backlight_ops,
&props);
if (IS_ERR(bl)) {
dev_err(&pdev->dev, "failed to register backlight\n");
return PTR_ERR(bl);
}
bl->props.brightness = gbl->def_value;
backlight_update_status(bl);
platform_set_drvdata(pdev, bl);
return 0;
}
#ifdef CONFIG_OF
static struct of_device_id gpio_backlight_of_match[] = {
{ .compatible = "gpio-backlight" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, gpio_backlight_of_match);
#endif
static struct platform_driver gpio_backlight_driver = {
.driver = {
.name = "gpio-backlight",
.of_match_table = of_match_ptr(gpio_backlight_of_match),
},
.probe = gpio_backlight_probe,
};
module_platform_driver(gpio_backlight_driver);
MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
MODULE_DESCRIPTION("GPIO-based Backlight Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:gpio-backlight");