leds: add a driver for syscon-based LEDs (535f09cc) · Commits · 戴 / test

drivers/leds/Kconfig

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		@@ -478,6 +478,16 @@ config LEDS_BLINKM
		This option enables support for the BlinkM RGB LED connected
		through I2C. Say Y to enable support for the BlinkM LED.

		config LEDS_SYSCON
		bool "LED support for LEDs on system controllers"
		depends on LEDS_CLASS=y
		depends on MFD_SYSCON
		depends on OF
		help
		This option enabled support for the LEDs on syscon type
		devices. This will only work with device tree enabled
		devices.

		config LEDS_VERSATILE
		tristate "LED support for the ARM Versatile and RealView"
		depends on ARCH_REALVIEW \|\| ARCH_VERSATILE

drivers/leds/Makefile

+1 −0

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		@@ -53,6 +53,7 @@ obj-$(CONFIG_LEDS_ASIC3) += leds-asic3.o
		obj-$(CONFIG_LEDS_MAX8997) += leds-max8997.o
		obj-$(CONFIG_LEDS_LM355x) += leds-lm355x.o
		obj-$(CONFIG_LEDS_BLINKM) += leds-blinkm.o
		obj-$(CONFIG_LEDS_SYSCON) += leds-syscon.o
		obj-$(CONFIG_LEDS_VERSATILE) += leds-versatile.o

		# LED SPI Drivers

drivers/leds/leds-syscon.c

0 → 100644

+166 −0

Original line number	Diff line number	Diff line
		/*
		* Generic Syscon LEDs Driver
		*
		* Copyright (c) 2014, Linaro Limited
		* Author: Linus Walleij <linus.walleij@linaro.org>
		*
		* This program is free software; you can redistribute it and/or
		* modify it under the terms of the GNU General Public License as
		* published by the Free Software Foundation; either version 2 of
		* the License, or (at your option) any later version.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		* You should have received a copy of the GNU General Public License
		* along with this program; if not, write to the Free Software
		* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
		* MA 02111-1307 USA
		*
		* This driver provides system reboot functionality for APM X-Gene SoC.
		* For system shutdown, this is board specify. If a board designer
		* implements GPIO shutdown, use the gpio-poweroff.c driver.
		*/
		#include <linux/io.h>
		#include <linux/of_device.h>
		#include <linux/of_address.h>
		#include <linux/platform_device.h>
		#include <linux/stat.h>
		#include <linux/slab.h>
		#include <linux/mfd/syscon.h>
		#include <linux/regmap.h>
		#include <linux/leds.h>

		/**
		* struct syscon_led - state container for syscon based LEDs
		* @cdev: LED class device for this LED
		* @map: regmap to access the syscon device backing this LED
		* @offset: the offset into the syscon regmap for the LED register
		* @mask: the bit in the register corresponding to the LED
		* @state: current state of the LED
		*/
		struct syscon_led {
		struct led_classdev cdev;
		struct regmap *map;
		u32 offset;
		u32 mask;
		bool state;
		};

		static void syscon_led_set(struct led_classdev *led_cdev,
		enum led_brightness value)
		{
		struct syscon_led *sled =
		container_of(led_cdev, struct syscon_led, cdev);
		u32 val;
		int ret;

		if (value == LED_OFF) {
		val = 0;
		sled->state = false;
		} else {
		val = sled->mask;
		sled->state = true;
		}

		ret = regmap_update_bits(sled->map, sled->offset, sled->mask, val);
		if (ret < 0)
		dev_err(sled->cdev.dev, "error updating LED status\n");
		}

		static const struct of_device_id syscon_match[] = {
		{ .compatible = "syscon", },
		{},
		};

		static int __init syscon_leds_init(void)
		{
		const struct of_device_id *devid;
		struct device_node *np;
		struct device_node *child;
		struct regmap *map;
		struct platform_device *pdev;
		struct device *dev;
		int ret;

		np = of_find_matching_node_and_match(NULL, syscon_match,
		&devid);
		if (!np)
		return -ENODEV;

		map = syscon_node_to_regmap(np);
		if (IS_ERR(map))
		return PTR_ERR(map);

		/*
		* If the map is there, the device should be there, we allocate
		* memory on the syscon device's behalf here.
		*/
		pdev = of_find_device_by_node(np);
		if (!pdev)
		return -ENODEV;
		dev = &pdev->dev;

		for_each_available_child_of_node(np, child) {
		struct syscon_led *sled;
		const char *state;

		/* Only check for register-bit-leds */
		if (of_property_match_string(child, "compatible",
		"register-bit-led") < 0)
		continue;

		sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL);
		if (!sled)
		return -ENOMEM;

		sled->map = map;

		if (of_property_read_u32(child, "offset", &sled->offset))
		return -EINVAL;
		if (of_property_read_u32(child, "mask", &sled->mask))
		return -EINVAL;
		sled->cdev.name =
		of_get_property(child, "label", NULL) ? : child->name;
		sled->cdev.default_trigger =
		of_get_property(child, "linux,default-trigger", NULL);

		state = of_get_property(child, "default-state", NULL);
		if (state) {
		if (!strcmp(state, "keep")) {
		u32 val;

		ret = regmap_read(map, sled->offset, &val);
		if (ret < 0)
		return ret;
		sled->state = !!(val & sled->mask);
		} else if (!strcmp(state, "on")) {
		sled->state = true;
		ret = regmap_update_bits(map, sled->offset,
		sled->mask,
		sled->mask);
		if (ret < 0)
		return ret;
		} else {
		sled->state = false;
		ret = regmap_update_bits(map, sled->offset,
		sled->mask, 0);
		if (ret < 0)
		return ret;
		}

		}
		sled->cdev.brightness_set = syscon_led_set;

		ret = led_classdev_register(dev, &sled->cdev);
		if (ret < 0)
		return ret;

		dev_info(dev, "registered LED %s\n", sled->cdev.name);
		}

		return 0;
		}
		device_initcall(syscon_leds_init);

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