Merge tag 'leds_for_4.18-rc1' of...

Merge tag 'leds_for_4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED updates from Jacek Anaszewski:
 "This was quite a fruitful cycle, taking into account usual traffic on
  linux-leds list, as we managed to merge three new LED class drivers.

  New LED class drivers with related DT bindings:
   - add LED driver for CR0014114 board
   - add Spreadtrum SC27xx breathing light controller driver
   - introduce the lm3601x LED driver

  LED class fix:
   - ensure workqueue is initialized before setting brightness

  Improvements and fixes to existing LED class drivers:
   - fix return value check in sc27xx_led_probe()
   - use sysfs_match_string() helper in wm831x_status_src_store()"

* tag 'leds_for_4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  leds: class: ensure workqueue is initialized before setting brightness
  leds: lm3601x: Introduce the lm3601x LED driver
  dt: bindings: lm3601x: Introduce the lm3601x driver
  leds: sc27xx: Fix return value check in sc27xx_led_probe()
  leds: Add Spreadtrum SC27xx breathing light controller driver
  dt-bindings: leds: Add SC27xx breathing light controller documentation
  leds: wm831x-status: Use sysfs_match_string() helper
  leds: add LED driver for CR0014114 board
  dt-bindings: Add vendor prefix and docs for CR0014114

Documentation/devicetree/bindings/leds/leds-cr0014114.txt

+Crane Merchandising System - cr0014114 LED driver
+-------------------------------------------------
+
+This LED Board is widely used in vending machines produced
+by Crane Merchandising Systems.
+
+Required properties:
+- compatible: "crane,cr0014114"
+
+Property rules described in Documentation/devicetree/bindings/spi/spi-bus.txt
+apply. In particular, "reg" and "spi-max-frequency" properties must be given.
+
+LED sub-node properties:
+- label :
+	see Documentation/devicetree/bindings/leds/common.txt
+- linux,default-trigger : (optional)
+	see Documentation/devicetree/bindings/leds/common.txt
+
+Example
+-------
+
+led-controller@0 {
+	compatible = "crane,cr0014114";
+	reg = <0>;
+	spi-max-frequency = <50000>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	led@0 {
+		reg = <0>;
+		label = "red:coin";
+	};
+	led@1 {
+		reg = <1>;
+		label = "green:coin";
+	};
+	led@2 {
+		reg = <2>;
+		label = "blue:coin";
+	};
+	led@3 {
+		reg = <3>;
+		label = "red:bill";
+	};
+	led@4 {
+		reg = <4>;
+		label = "green:bill";
+	};
+	led@5 {
+		reg = <5>;
+		label = "blue:bill";
+	};
+	...
+};

Documentation/devicetree/bindings/leds/leds-lm3601x.txt

+* Texas Instruments - lm3601x Single-LED Flash Driver
+
+The LM3601X are ultra-small LED flash drivers that
+provide a high level of adjustability.
+
+Required properties:
+	- compatible : Can be one of the following
+		"ti,lm36010"
+		"ti,lm36011"
+	- reg : I2C slave address
+	- #address-cells : 1
+	- #size-cells : 0
+
+Required child properties:
+	- reg : 0 - Indicates a IR mode
+		1 - Indicates a Torch (white LED) mode
+
+Required properties for flash LED child nodes:
+	See Documentation/devicetree/bindings/leds/common.txt
+	- flash-max-microamp : Range from 11mA - 1.5A
+	- flash-max-timeout-us : Range from 40ms - 1600ms
+	- led-max-microamp : Range from 2.4mA - 376mA
+
+Optional child properties:
+	- label : see Documentation/devicetree/bindings/leds/common.txt
+
+Example:
+led-controller@64 {
+	compatible = "ti,lm36010";
+	#address-cells = <1>;
+	#size-cells = <0>;
+	reg = <0x64>;
+
+	led@0 {
+		reg = <1>;
+		label = "white:torch";
+		led-max-microamp = <376000>;
+		flash-max-microamp = <1500000>;
+		flash-max-timeout-us = <1600000>;
+	};
+}
+
+For more product information please see the links below:
+http://www.ti.com/product/LM36010
+http://www.ti.com/product/LM36011

Documentation/devicetree/bindings/leds/leds-sc27xx-bltc.txt

+LEDs connected to Spreadtrum SC27XX PMIC breathing light controller
+
+The SC27xx breathing light controller supports to 3 outputs:
+red LED, green LED and blue LED. Each LED can work at normal
+PWM mode or breath light mode.
+
+Required properties:
+- compatible: Should be "sprd,sc2731-bltc".
+- #address-cells: Must be 1.
+- #size-cells: Must be 0.
+- reg: Specify the controller address.
+
+Required child properties:
+- reg: Port this LED is connected to.
+
+Optional child properties:
+- label: See Documentation/devicetree/bindings/leds/common.txt.
+
+Examples:
+
+led-controller@200 {
+	compatible = "sprd,sc2731-bltc";
+	#address-cells = <1>;
+	#size-cells = <0>;
+	reg = <0x200>;
+
+	led@0 {
+		label = "red";
+		reg = <0x0>;
+	};
+
+	led@1 {
+		label = "green";
+		reg = <0x1>;
+	};
+
+	led@2 {
+		label = "blue";
+		reg = <0x2>;
+	};
+};

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -75,6 +75,7 @@ cnxt	Conexant Systems, Inc.
 compulab	CompuLab Ltd.
 cortina	Cortina Systems, Inc.
 cosmic	Cosmic Circuits
+crane	Crane Connectivity Solutions
 creative	Creative Technology Ltd
 crystalfontz	Crystalfontz America, Inc.
 cubietech	Cubietech, Ltd.

drivers/leds/Kconfig

@@ -104,6 +104,19 @@ config LEDS_CPCAP
 	  This option enables support for LEDs offered by Motorola's
 	  CPCAP PMIC.
 
+config LEDS_CR0014114
+	tristate "LED Support for Crane CR0014114"
+	depends on LEDS_CLASS
+	depends on SPI
+	depends on OF
+	help
+	  This option enables support for CR0014114 LED Board which
+	  is widely used in vending machines produced by
+	  Crane Merchandising Systems.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called leds-cr0014114.
+
 config LEDS_LM3530
 	tristate "LCD Backlight driver for LM3530"
 	depends on LEDS_CLASS
@@ -145,6 +158,15 @@ config LEDS_LM3692X
 	  This option enables support for the TI LM3692x family
 	  of white LED string drivers used for backlighting.
 
+config LEDS_LM3601X
+	tristate "LED support for LM3601x Chips"
+	depends on LEDS_CLASS && I2C
+	depends on LEDS_CLASS_FLASH
+	select REGMAP_I2C
+	help
+	  This option enables support for the TI LM3601x family
+	  of flash, torch and indicator classes.
+
 config LEDS_LOCOMO
 	tristate "LED Support for Locomo device"
 	depends on LEDS_CLASS
@@ -647,6 +669,17 @@ config LEDS_IS31FL32XX
 	  LED controllers. They are I2C devices with multiple constant-current
 	  channels, each with independent 256-level PWM control.
 
+config LEDS_SC27XX_BLTC
+	tristate "LED support for the SC27xx breathing light controller"
+	depends on LEDS_CLASS && MFD_SC27XX_PMIC
+	depends on OF
+	help
+	  Say Y here to include support for the SC27xx breathing light controller
+	  LEDs.
+
+	  This driver can also be built as a module. If so the module will be
+	  called leds-sc27xx-bltc.
+
 comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
 
 config LEDS_BLINKM

drivers/leds/Makefile

@@ -76,8 +76,11 @@ obj-$(CONFIG_LEDS_MLXREG)		+= leds-mlxreg.o
 obj-$(CONFIG_LEDS_NIC78BX)		+= leds-nic78bx.o
 obj-$(CONFIG_LEDS_MT6323)		+= leds-mt6323.o
 obj-$(CONFIG_LEDS_LM3692X)		+= leds-lm3692x.o
+obj-$(CONFIG_LEDS_SC27XX_BLTC)		+= leds-sc27xx-bltc.o
+obj-$(CONFIG_LEDS_LM3601X)		+= leds-lm3601x.o
 
 # LED SPI Drivers
+obj-$(CONFIG_LEDS_CR0014114)		+= leds-cr0014114.o
 obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o
 
 # LED Userspace Drivers

drivers/leds/led-class.c

@@ -260,10 +260,14 @@ int of_led_classdev_register(struct device *parent, struct device_node *np,
 	if (ret < 0)
 		return ret;
 
+	mutex_init(&led_cdev->led_access);
+	mutex_lock(&led_cdev->led_access);
 	led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
 				led_cdev, led_cdev->groups, "%s", name);
-	if (IS_ERR(led_cdev->dev))
+	if (IS_ERR(led_cdev->dev)) {
+		mutex_unlock(&led_cdev->led_access);
 		return PTR_ERR(led_cdev->dev);
+	}
 	led_cdev->dev->of_node = np;
 
 	if (ret)
@@ -274,6 +278,7 @@ int of_led_classdev_register(struct device *parent, struct device_node *np,
 		ret = led_add_brightness_hw_changed(led_cdev);
 		if (ret) {
 			device_unregister(led_cdev->dev);
+			mutex_unlock(&led_cdev->led_access);
 			return ret;
 		}
 	}
@@ -285,7 +290,6 @@ int of_led_classdev_register(struct device *parent, struct device_node *np,
 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 	led_cdev->brightness_hw_changed = -1;
 #endif
-	mutex_init(&led_cdev->led_access);
 	/* add to the list of leds */
 	down_write(&leds_list_lock);
 	list_add_tail(&led_cdev->node, &leds_list);
@@ -302,6 +306,8 @@ int of_led_classdev_register(struct device *parent, struct device_node *np,
 	led_trigger_set_default(led_cdev);
 #endif
 
+	mutex_unlock(&led_cdev->led_access);
+
 	dev_dbg(parent, "Registered led device: %s\n",
 			led_cdev->name);
 

drivers/leds/leds-cr0014114.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 Crane Merchandising Systems. All rights reserved.
+// Copyright (C) 2018 Oleh Kravchenko <oleg@kaa.org.ua>
+
+#include <linux/delay.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/spi/spi.h>
+#include <linux/workqueue.h>
+#include <uapi/linux/uleds.h>
+
+/*
+ *  CR0014114 SPI protocol descrtiption:
+ *  +----+-----------------------------------+----+
+ *  | CMD|             BRIGHTNESS            |CRC |
+ *  +----+-----------------------------------+----+
+ *  |    | LED0| LED1| LED2| LED3| LED4| LED5|    |
+ *  |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |
+ *  |    |R|G|B|R|G|B|R|G|B|R|G|B|R|G|B|R|G|B|    |
+ *  | 1  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1  |
+ *  |    |1|1|1|1|1|1|1|1|1|1|1|1|1|1|1|1|1|1|    |
+ *  |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |
+ *  |    |               18                  |    |
+ *  +----+-----------------------------------+----+
+ *  |                    20                       |
+ *  +---------------------------------------------+
+ *
+ *  PS: Boards can be connected to the chain:
+ *      SPI -> board0 -> board1 -> board2 ..
+ */
+
+/* CR0014114 SPI commands */
+#define CR_SET_BRIGHTNESS	0x80
+#define CR_INIT_REENUMERATE	0x81
+#define CR_NEXT_REENUMERATE	0x82
+
+/* CR0014114 default settings */
+#define CR_MAX_BRIGHTNESS	GENMASK(6, 0)
+#define CR_FW_DELAY_MSEC	10
+#define CR_RECOUNT_DELAY	(HZ * 3600)
+
+struct cr0014114_led {
+	char			name[LED_MAX_NAME_SIZE];
+	struct cr0014114	*priv;
+	struct led_classdev	ldev;
+	u8			brightness;
+};
+
+struct cr0014114 {
+	bool			do_recount;
+	size_t			count;
+	struct delayed_work	work;
+	struct device		*dev;
+	struct mutex		lock;
+	struct spi_device	*spi;
+	u8			*buf;
+	unsigned long		delay;
+	struct cr0014114_led	leds[];
+};
+
+static void cr0014114_calc_crc(u8 *buf, const size_t len)
+{
+	size_t	i;
+	u8	crc;
+
+	for (i = 1, crc = 1; i < len - 1; i++)
+		crc += buf[i];
+	crc |= BIT(7);
+
+	/* special case when CRC matches the SPI commands */
+	if (crc == CR_SET_BRIGHTNESS ||
+	    crc == CR_INIT_REENUMERATE ||
+	    crc == CR_NEXT_REENUMERATE)
+		crc = 0xfe;
+
+	buf[len - 1] = crc;
+}
+
+static int cr0014114_recount(struct cr0014114 *priv)
+{
+	int	ret;
+	size_t	i;
+	u8	cmd;
+
+	dev_dbg(priv->dev, "LEDs recount is started\n");
+
+	cmd = CR_INIT_REENUMERATE;
+	ret = spi_write(priv->spi, &cmd, sizeof(cmd));
+	if (ret)
+		goto err;
+
+	cmd = CR_NEXT_REENUMERATE;
+	for (i = 0; i < priv->count; i++) {
+		msleep(CR_FW_DELAY_MSEC);
+
+		ret = spi_write(priv->spi, &cmd, sizeof(cmd));
+		if (ret)
+			goto err;
+	}
+
+err:
+	dev_dbg(priv->dev, "LEDs recount is finished\n");
+
+	if (ret)
+		dev_err(priv->dev, "with error %d", ret);
+
+	return ret;
+}
+
+static int cr0014114_sync(struct cr0014114 *priv)
+{
+	int		ret;
+	size_t		i;
+	unsigned long	udelay, now = jiffies;
+
+	/* to avoid SPI mistiming with firmware we should wait some time */
+	if (time_after(priv->delay, now)) {
+		udelay = jiffies_to_usecs(priv->delay - now);
+		usleep_range(udelay, udelay + 1);
+	}
+
+	if (unlikely(priv->do_recount)) {
+		ret = cr0014114_recount(priv);
+		if (ret)
+			goto err;
+
+		priv->do_recount = false;
+		msleep(CR_FW_DELAY_MSEC);
+	}
+
+	priv->buf[0] = CR_SET_BRIGHTNESS;
+	for (i = 0; i < priv->count; i++)
+		priv->buf[i + 1] = priv->leds[i].brightness;
+	cr0014114_calc_crc(priv->buf, priv->count + 2);
+	ret = spi_write(priv->spi, priv->buf, priv->count + 2);
+
+err:
+	priv->delay = jiffies + msecs_to_jiffies(CR_FW_DELAY_MSEC);
+
+	return ret;
+}
+
+static void cr0014114_recount_work(struct work_struct *work)
+{
+	int			ret;
+	struct cr0014114	*priv = container_of(work,
+						     struct cr0014114,
+						     work.work);
+
+	mutex_lock(&priv->lock);
+	priv->do_recount = true;
+	ret = cr0014114_sync(priv);
+	mutex_unlock(&priv->lock);
+
+	if (ret)
+		dev_warn(priv->dev, "sync of LEDs failed %d\n", ret);
+
+	schedule_delayed_work(&priv->work, CR_RECOUNT_DELAY);
+}
+
+static int cr0014114_set_sync(struct led_classdev *ldev,
+			      enum led_brightness brightness)
+{
+	int			ret;
+	struct cr0014114_led    *led = container_of(ldev,
+						    struct cr0014114_led,
+						    ldev);
+
+	dev_dbg(led->priv->dev, "Set brightness of %s to %d\n",
+		led->name, brightness);
+
+	mutex_lock(&led->priv->lock);
+	led->brightness = (u8)brightness;
+	ret = cr0014114_sync(led->priv);
+	mutex_unlock(&led->priv->lock);
+
+	return ret;
+}
+
+static int cr0014114_probe_dt(struct cr0014114 *priv)
+{
+	size_t			i = 0;
+	struct cr0014114_led	*led;
+	struct fwnode_handle	*child;
+	struct device_node	*np;
+	int			ret;
+	const char		*str;
+
+	device_for_each_child_node(priv->dev, child) {
+		np = to_of_node(child);
+		led = &priv->leds[i];
+
+		ret = fwnode_property_read_string(child, "label", &str);
+		if (ret)
+			snprintf(led->name, sizeof(led->name),
+				 "cr0014114::");
+		else
+			snprintf(led->name, sizeof(led->name),
+				 "cr0014114:%s", str);
+
+		fwnode_property_read_string(child, "linux,default-trigger",
+					    &led->ldev.default_trigger);
+
+		led->priv			  = priv;
+		led->ldev.name			  = led->name;
+		led->ldev.max_brightness	  = CR_MAX_BRIGHTNESS;
+		led->ldev.brightness_set_blocking = cr0014114_set_sync;
+
+		ret = devm_of_led_classdev_register(priv->dev, np,
+						    &led->ldev);
+		if (ret) {
+			dev_err(priv->dev,
+				"failed to register LED device %s, err %d",
+				led->name, ret);
+			fwnode_handle_put(child);
+			return ret;
+		}
+
+		led->ldev.dev->of_node = np;
+
+		i++;
+	}
+
+	return 0;
+}
+
+static int cr0014114_probe(struct spi_device *spi)
+{
+	struct cr0014114	*priv;
+	size_t			count;
+	int			ret;
+
+	count = device_get_child_node_count(&spi->dev);
+	if (!count) {
+		dev_err(&spi->dev, "LEDs are not defined in device tree!");
+		return -ENODEV;
+	}
+
+	priv = devm_kzalloc(&spi->dev,
+			    sizeof(*priv) + sizeof(*priv->leds) * count,
+			    GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->buf = devm_kzalloc(&spi->dev, count + 2, GFP_KERNEL);
+	if (!priv->buf)
+		return -ENOMEM;
+
+	mutex_init(&priv->lock);
+	INIT_DELAYED_WORK(&priv->work, cr0014114_recount_work);
+	priv->count	= count;
+	priv->dev	= &spi->dev;
+	priv->spi	= spi;
+	priv->delay	= jiffies -
+			  msecs_to_jiffies(CR_FW_DELAY_MSEC);
+
+	priv->do_recount = true;
+	ret = cr0014114_sync(priv);
+	if (ret) {
+		dev_err(priv->dev, "first recount failed %d\n", ret);
+		return ret;
+	}
+
+	priv->do_recount = true;
+	ret = cr0014114_sync(priv);
+	if (ret) {
+		dev_err(priv->dev, "second recount failed %d\n", ret);
+		return ret;
+	}
+
+	ret = cr0014114_probe_dt(priv);
+	if (ret)
+		return ret;
+
+	/* setup recount work to workaround buggy firmware */
+	schedule_delayed_work(&priv->work, CR_RECOUNT_DELAY);
+
+	spi_set_drvdata(spi, priv);
+
+	return 0;
+}
+
+static int cr0014114_remove(struct spi_device *spi)
+{
+	struct cr0014114 *priv = spi_get_drvdata(spi);
+
+	cancel_delayed_work_sync(&priv->work);
+	mutex_destroy(&priv->lock);
+
+	return 0;
+}
+
+static const struct of_device_id cr0014114_dt_ids[] = {
+	{ .compatible = "crane,cr0014114", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, cr0014114_dt_ids);
+
+static struct spi_driver cr0014114_driver = {
+	.probe		= cr0014114_probe,
+	.remove		= cr0014114_remove,
+	.driver = {
+		.name		= KBUILD_MODNAME,
+		.of_match_table	= cr0014114_dt_ids,
+	},
+};
+
+module_spi_driver(cr0014114_driver);
+
+MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>");
+MODULE_DESCRIPTION("cr0014114 LED driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("spi:cr0014114");

drivers/leds/leds-sc27xx-bltc.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Spreadtrum Communications Inc.
+
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <uapi/linux/uleds.h>
+
+/* PMIC global control register definition */
+#define SC27XX_MODULE_EN0	0xc08
+#define SC27XX_CLK_EN0		0xc18
+#define SC27XX_RGB_CTRL		0xebc
+
+#define SC27XX_BLTC_EN		BIT(9)
+#define SC27XX_RTC_EN		BIT(7)
+#define SC27XX_RGB_PD		BIT(0)
+
+/* Breathing light controller register definition */
+#define SC27XX_LEDS_CTRL	0x00
+#define SC27XX_LEDS_PRESCALE	0x04
+#define SC27XX_LEDS_DUTY	0x08
+#define SC27XX_LEDS_CURVE0	0x0c
+#define SC27XX_LEDS_CURVE1	0x10
+
+#define SC27XX_CTRL_SHIFT	4
+#define SC27XX_LED_RUN		BIT(0)
+#define SC27XX_LED_TYPE		BIT(1)
+
+#define SC27XX_DUTY_SHIFT	8
+#define SC27XX_DUTY_MASK	GENMASK(15, 0)
+#define SC27XX_MOD_MASK		GENMASK(7, 0)
+
+#define SC27XX_LEDS_OFFSET	0x10
+#define SC27XX_LEDS_MAX		3
+
+struct sc27xx_led {
+	char name[LED_MAX_NAME_SIZE];
+	struct led_classdev ldev;
+	struct sc27xx_led_priv *priv;
+	u8 line;
+	bool active;
+};
+
+struct sc27xx_led_priv {
+	struct sc27xx_led leds[SC27XX_LEDS_MAX];
+	struct regmap *regmap;
+	struct mutex lock;
+	u32 base;
+};
+
+#define to_sc27xx_led(ldev) \
+	container_of(ldev, struct sc27xx_led, ldev)
+
+static int sc27xx_led_init(struct regmap *regmap)
+{
+	int err;
+
+	err = regmap_update_bits(regmap, SC27XX_MODULE_EN0, SC27XX_BLTC_EN,
+				 SC27XX_BLTC_EN);
+	if (err)
+		return err;
+
+	err = regmap_update_bits(regmap, SC27XX_CLK_EN0, SC27XX_RTC_EN,
+				 SC27XX_RTC_EN);
+	if (err)
+		return err;
+
+	return regmap_update_bits(regmap, SC27XX_RGB_CTRL, SC27XX_RGB_PD, 0);
+}
+
+static u32 sc27xx_led_get_offset(struct sc27xx_led *leds)
+{
+	return leds->priv->base + SC27XX_LEDS_OFFSET * leds->line;
+}
+
+static int sc27xx_led_enable(struct sc27xx_led *leds, enum led_brightness value)
+{
+	u32 base = sc27xx_led_get_offset(leds);
+	u32 ctrl_base = leds->priv->base + SC27XX_LEDS_CTRL;
+	u8 ctrl_shift = SC27XX_CTRL_SHIFT * leds->line;
+	struct regmap *regmap = leds->priv->regmap;
+	int err;
+
+	err = regmap_update_bits(regmap, base + SC27XX_LEDS_DUTY,
+				 SC27XX_DUTY_MASK,
+				 (value << SC27XX_DUTY_SHIFT) |
+				 SC27XX_MOD_MASK);
+	if (err)
+		return err;
+
+	return regmap_update_bits(regmap, ctrl_base,
+			(SC27XX_LED_RUN | SC27XX_LED_TYPE) << ctrl_shift,
+			(SC27XX_LED_RUN | SC27XX_LED_TYPE) << ctrl_shift);
+}
+
+static int sc27xx_led_disable(struct sc27xx_led *leds)
+{
+	struct regmap *regmap = leds->priv->regmap;
+	u32 ctrl_base = leds->priv->base + SC27XX_LEDS_CTRL;
+	u8 ctrl_shift = SC27XX_CTRL_SHIFT * leds->line;
+
+	return regmap_update_bits(regmap, ctrl_base,
+			(SC27XX_LED_RUN | SC27XX_LED_TYPE) << ctrl_shift, 0);
+}
+
+static int sc27xx_led_set(struct led_classdev *ldev, enum led_brightness value)
+{
+	struct sc27xx_led *leds = to_sc27xx_led(ldev);
+	int err;
+
+	mutex_lock(&leds->priv->lock);
+
+	if (value == LED_OFF)
+		err = sc27xx_led_disable(leds);
+	else
+		err = sc27xx_led_enable(leds, value);
+
+	mutex_unlock(&leds->priv->lock);
+
+	return err;
+}
+
+static int sc27xx_led_register(struct device *dev, struct sc27xx_led_priv *priv)
+{
+	int i, err;
+
+	err = sc27xx_led_init(priv->regmap);
+	if (err)
+		return err;
+
+	for (i = 0; i < SC27XX_LEDS_MAX; i++) {
+		struct sc27xx_led *led = &priv->leds[i];
+
+		if (!led->active)
+			continue;
+
+		led->line = i;
+		led->priv = priv;
+		led->ldev.name = led->name;
+		led->ldev.brightness_set_blocking = sc27xx_led_set;
+
+		err = devm_led_classdev_register(dev, &led->ldev);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int sc27xx_led_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node, *child;
+	struct sc27xx_led_priv *priv;
+	const char *str;
+	u32 base, count, reg;
+	int err;
+
+	count = of_get_child_count(np);
+	if (!count || count > SC27XX_LEDS_MAX)
+		return -EINVAL;
+
+	err = of_property_read_u32(np, "reg", &base);
+	if (err) {
+		dev_err(dev, "fail to get reg of property\n");
+		return err;
+	}
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+	mutex_init(&priv->lock);
+	priv->base = base;
+	priv->regmap = dev_get_regmap(dev->parent, NULL);
+	if (!priv->regmap) {
+		err = -ENODEV;
+		dev_err(dev, "failed to get regmap: %d\n", err);
+		return err;
+	}
+
+	for_each_child_of_node(np, child) {
+		err = of_property_read_u32(child, "reg", &reg);
+		if (err) {
+			of_node_put(child);
+			mutex_destroy(&priv->lock);
+			return err;
+		}
+
+		if (reg >= SC27XX_LEDS_MAX || priv->leds[reg].active) {
+			of_node_put(child);
+			mutex_destroy(&priv->lock);
+			return -EINVAL;
+		}
+
+		priv->leds[reg].active = true;
+
+		err = of_property_read_string(child, "label", &str);
+		if (err)
+			snprintf(priv->leds[reg].name, LED_MAX_NAME_SIZE,
+				 "sc27xx::");
+		else
+			snprintf(priv->leds[reg].name, LED_MAX_NAME_SIZE,
+				 "sc27xx:%s", str);
+	}
+
+	err = sc27xx_led_register(dev, priv);
+	if (err)
+		mutex_destroy(&priv->lock);
+
+	return err;
+}
+
+static int sc27xx_led_remove(struct platform_device *pdev)
+{
+	struct sc27xx_led_priv *priv = platform_get_drvdata(pdev);
+
+	mutex_destroy(&priv->lock);
+	return 0;
+}
+
+static const struct of_device_id sc27xx_led_of_match[] = {
+	{ .compatible = "sprd,sc2731-bltc", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sc27xx_led_of_match);
+
+static struct platform_driver sc27xx_led_driver = {
+	.driver = {
+		.name = "sprd-bltc",
+		.of_match_table = sc27xx_led_of_match,
+	},
+	.probe = sc27xx_led_probe,
+	.remove = sc27xx_led_remove,
+};
+
+module_platform_driver(sc27xx_led_driver);
+
+MODULE_DESCRIPTION("Spreadtrum SC27xx breathing light controller driver");
+MODULE_AUTHOR("Xiaotong Lu <xiaotong.lu@spreadtrum.com>");
+MODULE_LICENSE("GPL v2");

drivers/leds/leds-wm831x-status.c

@@ -188,25 +188,15 @@ static ssize_t wm831x_status_src_store(struct device *dev,
 {
 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
 	struct wm831x_status *led = to_wm831x_status(led_cdev);
-	char name[20];
 	int i;
-	size_t len;
 
-	name[sizeof(name) - 1] = '\0';
-	strncpy(name, buf, sizeof(name) - 1);
-	len = strlen(name);
-
-	if (len && name[len - 1] == '\n')
-		name[len - 1] = '\0';
-
-	for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) {
-		if (!strcmp(name, led_src_texts[i])) {
+	i = sysfs_match_string(led_src_texts, buf);
+	if (i >= 0) {
 		mutex_lock(&led->mutex);
 		led->src = i;
 		mutex_unlock(&led->mutex);
 		wm831x_status_set(led);
 	}
-	}
 
 	return size;
 }