Merge tag 'backlight-next-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight (50950626) · Commits · 戴 / test

drivers/video/backlight/gpio_backlight.c

+9 −14

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		#include <linux/of_gpio.h>
		#include <linux/platform_data/gpio_backlight.h>
		#include <linux/platform_device.h>
		#include <linux/property.h>
		#include <linux/slab.h>

		struct gpio_backlight {
		@@ -58,11 +59,10 @@ static int gpio_backlight_probe_dt(struct platform_device *pdev,
		struct gpio_backlight *gbl)
		{
		struct device *dev = &pdev->dev;
		struct device_node *np = dev->of_node;
		enum gpiod_flags flags;
		int ret;

		gbl->def_value = of_property_read_bool(np, "default-on");
		gbl->def_value = device_property_read_bool(dev, "default-on");
		flags = gbl->def_value ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;

		gbl->gpiod = devm_gpiod_get(dev, NULL, flags);
		@@ -86,26 +86,19 @@ static int gpio_backlight_probe(struct platform_device *pdev)
		struct backlight_properties props;
		struct backlight_device *bl;
		struct gpio_backlight *gbl;
		struct device_node *np = pdev->dev.of_node;
		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) {
		if (pdev->dev.fwnode) {
		ret = gpio_backlight_probe_dt(pdev, gbl);
		if (ret)
		return ret;
		} else {
		} else if (pdata) {
		/*
		* Legacy platform data GPIO retrieveal. Do not expand
		* the use of this code path, currently only used by one
		@@ -126,6 +119,10 @@ static int gpio_backlight_probe(struct platform_device *pdev)
		gbl->gpiod = gpio_to_desc(pdata->gpio);
		if (!gbl->gpiod)
		return -EINVAL;
		} else {
		dev_err(&pdev->dev,
		"failed to find platform data or device tree node.\n");
		return -ENODEV;
		}

		memset(&props, 0, sizeof(props));
		@@ -146,19 +143,17 @@ static int gpio_backlight_probe(struct platform_device *pdev)
		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),
		.of_match_table = gpio_backlight_of_match,
		},
		.probe = gpio_backlight_probe,
		};

drivers/video/backlight/pwm_bl.c

+8 −22

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* linux/drivers/video/backlight/pwm_bl.c
		*
		* simple PWM based backlight control, board code has to setup
		* Simple PWM based backlight control, board code has to setup
		* 1) pin configuration so PWM waveforms can output
		* 2) platform_data being correctly configured
		*/
		@@ -191,29 +189,17 @@ int pwm_backlight_brightness_default(struct device *dev,
		struct platform_pwm_backlight_data *data,
		unsigned int period)
		{
		unsigned int counter = 0;
		unsigned int i, n;
		unsigned int i;
		u64 retval;

		/*
		* Count the number of bits needed to represent the period number. The
		* number of bits is used to calculate the number of levels used for the
		* brightness-levels table, the purpose of this calculation is have a
		* pre-computed table with enough levels to get linear brightness
		* perception. The period is divided by the number of bits so for a
		* 8-bit PWM we have 255 / 8 = 32 brightness levels or for a 16-bit PWM
		* we have 65535 / 16 = 4096 brightness levels.
		*
		* Note that this method is based on empirical testing on different
		* devices with PWM of 8 and 16 bits of resolution.
		* Once we have 4096 levels there's little point going much higher...
		* neither interactive sliders nor animation benefits from having
		* more values in the table.
		*/
		n = period;
		while (n) {
		counter += n % 2;
		n >>= 1;
		}
		data->max_brightness =
		min((int)DIV_ROUND_UP(period, fls(period)), 4096);

		data->max_brightness = DIV_ROUND_UP(period, counter);
		data->levels = devm_kcalloc(dev, data->max_brightness,
		sizeof(*data->levels), GFP_KERNEL);
		if (!data->levels)
		@@ -705,5 +691,5 @@ static struct platform_driver pwm_backlight_driver = {
		module_platform_driver(pwm_backlight_driver);

		MODULE_DESCRIPTION("PWM based Backlight Driver");
		MODULE_LICENSE("GPL");
		MODULE_LICENSE("GPL v2");
		MODULE_ALIAS("platform:pwm-backlight");

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