leds: Add new LED driver for lm3642 chips

This driver is a general version for LM642 led chip of TI.

LM3642 :
The LM3642 is a 4MHz fixed-frequency synchronous boost
converter plus 1.5A constant current driver for a high-current
white LED.
The LM3642 is controlled via an I2C-compatible interface.

Signed-off-by: G.Shark Jeong <[e-mail]>
Signed-off-by: Bryan Wu <[e-mail]>

drivers/leds/Kconfig

···
 	  hardware-accelerated blinking with maximum on and off periods of 9.8
 	  and 77 seconds respectively.
 
+config LEDS_LM3642
+	tristate "LED support for LM3642 Chip"
+	depends on LEDS_CLASS && I2C
+	select REGMAP_I2C
+	help
+	  This option enables support for LEDs connected to LM3642.
+	  The LM3642 is a 4MHz fixed-frequency synchronous boost
+	  converter plus 1.5A constant current driver for a high-current
+	  white LED.
+
+
 config LEDS_LOCOMO
 	tristate "LED Support for Locomo device"
 	depends on LEDS_CLASS

drivers/leds/Makefile

···
 obj-$(CONFIG_LEDS_LOCOMO)		+= leds-locomo.o
 obj-$(CONFIG_LEDS_LM3530)		+= leds-lm3530.o
 obj-$(CONFIG_LEDS_LM3533)		+= leds-lm3533.o
+obj-$(CONFIG_LEDS_LM3642)		+= leds-lm3642.o
 obj-$(CONFIG_LEDS_MIKROTIK_RB532)	+= leds-rb532.o
 obj-$(CONFIG_LEDS_S3C24XX)		+= leds-s3c24xx.o
 obj-$(CONFIG_LEDS_NET48XX)		+= leds-net48xx.o

drivers/leds/leds-lm3642.c

···
+/*
+* Simple driver for Texas Instruments LM3642 LED Flash driver chip
+* Copyright (C) 2012 Texas Instruments
+*
+* 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/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/fs.h>
+#include <linux/regmap.h>
+#include <linux/workqueue.h>
+#include <linux/platform_data/leds-lm3642.h>
+
+#define	REG_FILT_TIME			(0x0)
+#define	REG_IVFM_MODE			(0x1)
+#define	REG_TORCH_TIME			(0x6)
+#define	REG_FLASH			(0x8)
+#define	REG_I_CTRL			(0x9)
+#define	REG_ENABLE			(0xA)
+#define	REG_FLAG			(0xB)
+#define	REG_MAX				(0xB)
+
+#define	UVLO_EN_SHIFT			(7)
+#define	IVM_D_TH_SHIFT			(2)
+#define	TORCH_RAMP_UP_TIME_SHIFT	(3)
+#define	TORCH_RAMP_DN_TIME_SHIFT	(0)
+#define	INDUCTOR_I_LIMIT_SHIFT		(6)
+#define	FLASH_RAMP_TIME_SHIFT		(3)
+#define	FLASH_TOUT_TIME_SHIFT		(0)
+#define	TORCH_I_SHIFT			(4)
+#define	FLASH_I_SHIFT			(0)
+#define	IVFM_SHIFT			(7)
+#define	TX_PIN_EN_SHIFT			(6)
+#define	STROBE_PIN_EN_SHIFT		(5)
+#define	TORCH_PIN_EN_SHIFT		(4)
+#define	MODE_BITS_SHIFT			(0)
+
+#define	UVLO_EN_MASK			(0x1)
+#define	IVM_D_TH_MASK			(0x7)
+#define	TORCH_RAMP_UP_TIME_MASK		(0x7)
+#define	TORCH_RAMP_DN_TIME_MASK		(0x7)
+#define	INDUCTOR_I_LIMIT_MASK		(0x1)
+#define	FLASH_RAMP_TIME_MASK		(0x7)
+#define	FLASH_TOUT_TIME_MASK		(0x7)
+#define	TORCH_I_MASK			(0x7)
+#define	FLASH_I_MASK			(0xF)
+#define	IVFM_MASK			(0x1)
+#define	TX_PIN_EN_MASK			(0x1)
+#define	STROBE_PIN_EN_MASK		(0x1)
+#define	TORCH_PIN_EN_MASK		(0x1)
+#define	MODE_BITS_MASK			(0x73)
+#define EX_PIN_CONTROL_MASK		(0x71)
+#define EX_PIN_ENABLE_MASK		(0x70)
+
+enum lm3642_mode {
+	MODES_STASNDBY = 0,
+	MODES_INDIC,
+	MODES_TORCH,
+	MODES_FLASH
+};
+
+struct lm3642_chip_data {
+	struct device *dev;
+
+	struct led_classdev cdev_flash;
+	struct led_classdev cdev_torch;
+	struct led_classdev cdev_indicator;
+
+	struct work_struct work_flash;
+	struct work_struct work_torch;
+	struct work_struct work_indicator;
+
+	u8 br_flash;
+	u8 br_torch;
+	u8 br_indicator;
+
+	enum lm3642_torch_pin_enable torch_pin;
+	enum lm3642_strobe_pin_enable strobe_pin;
+	enum lm3642_tx_pin_enable tx_pin;
+
+	struct lm3642_platform_data *pdata;
+	struct regmap *regmap;
+	struct mutex lock;
+
+	unsigned int last_flag;
+};
+
+/* chip initialize */
+static int __devinit lm3642_chip_init(struct lm3642_chip_data *chip)
+{
+	unsigned int reg_val;
+	int ret;
+	struct lm3642_platform_data *pdata = chip->pdata;
+
+	/* set enable register */
+	ret = regmap_read(chip->regmap, REG_ENABLE, &reg_val);
+	if (ret < 0)
+		goto out;
+
+	reg_val &= (~EX_PIN_ENABLE_MASK);
+	reg_val |= pdata->tx_pin;
+	ret = regmap_write(chip->regmap, REG_ENABLE, reg_val);
+	if (ret < 0)
+		goto out;
+
+out:
+	dev_err(chip->dev, "Failed to read REG_ENABLE Register\n");
+	return ret;
+}
+
+/* chip control */
+static int lm3642_control(struct lm3642_chip_data *chip,
+			  u8 brightness, enum lm3642_mode opmode)
+{
+	int ret;
+
+	ret = regmap_read(chip->regmap, REG_FLAG, &chip->last_flag);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to read REG_FLAG Register\n");
+		goto out;
+	}
+
+	if (chip->last_flag)
+		dev_info(chip->dev, "Last FLAG is 0x%x\n", chip->last_flag);
+
+	/* brightness 0 means off-state */
+	if (!brightness)
+		opmode = MODES_STASNDBY;
+
+	switch (opmode) {
+	case MODES_TORCH:
+		ret = regmap_update_bits(chip->regmap, REG_I_CTRL,
+					 TORCH_I_MASK << TORCH_I_SHIFT,
+					 (brightness - 1) << TORCH_I_SHIFT);
+
+		if (chip->torch_pin)
+			opmode |= (TORCH_PIN_EN_MASK << TORCH_PIN_EN_SHIFT);
+		break;
+
+	case MODES_FLASH:
+		ret = regmap_update_bits(chip->regmap, REG_I_CTRL,
+					 FLASH_I_MASK << FLASH_I_SHIFT,
+					 (brightness - 1) << FLASH_I_SHIFT);
+
+		if (chip->strobe_pin)
+			opmode |= (STROBE_PIN_EN_MASK << STROBE_PIN_EN_SHIFT);
+		break;
+
+	case MODES_INDIC:
+		ret = regmap_update_bits(chip->regmap, REG_I_CTRL,
+					 TORCH_I_MASK << TORCH_I_SHIFT,
+					 (brightness - 1) << TORCH_I_SHIFT);
+		break;
+
+	case MODES_STASNDBY:
+
+		break;
+
+	default:
+		return ret;
+	}
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to write REG_I_CTRL Register\n");
+		goto out;
+	}
+
+	if (chip->tx_pin)
+		opmode |= (TX_PIN_EN_MASK << TX_PIN_EN_SHIFT);
+
+	ret = regmap_update_bits(chip->regmap, REG_ENABLE,
+				 MODE_BITS_MASK << MODE_BITS_SHIFT,
+				 opmode << MODE_BITS_SHIFT);
+out:
+	return ret;
+}
+
+/* torch */
+
+/* torch pin config for lm3642*/
+static ssize_t lm3642_torch_pin_store(struct device *dev,
+				      struct device_attribute *devAttr,
+				      const char *buf, size_t size)
+{
+	ssize_t ret;
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct lm3642_chip_data *chip =
+	    container_of(led_cdev, struct lm3642_chip_data, cdev_indicator);
+	unsigned int state;
+
+	ret = kstrtouint(buf, 10, &state);
+	if (ret)
+		goto out_strtoint;
+	if (state != 0)
+		state = 0x01 << TORCH_PIN_EN_SHIFT;
+
+	chip->torch_pin = state;
+	ret = regmap_update_bits(chip->regmap, REG_ENABLE,
+				 TORCH_PIN_EN_MASK << TORCH_PIN_EN_SHIFT,
+				 state);
+	if (ret < 0)
+		goto out;
+
+	return size;
+out:
+	dev_err(chip->dev, "%s:i2c access fail to register\n", __func__);
+	return size;
+out_strtoint:
+	dev_err(chip->dev, "%s: fail to change str to int\n", __func__);
+	return size;
+}
+
+static DEVICE_ATTR(torch_pin, 0666, NULL, lm3642_torch_pin_store);
+
+static void lm3642_deferred_torch_brightness_set(struct work_struct *work)
+{
+	struct lm3642_chip_data *chip =
+	    container_of(work, struct lm3642_chip_data, work_torch);
+
+	mutex_lock(&chip->lock);
+	lm3642_control(chip, chip->br_torch, MODES_TORCH);
+	mutex_unlock(&chip->lock);
+}
+
+static void lm3642_torch_brightness_set(struct led_classdev *cdev,
+					enum led_brightness brightness)
+{
+	struct lm3642_chip_data *chip =
+	    container_of(cdev, struct lm3642_chip_data, cdev_torch);
+
+	chip->br_torch = brightness;
+	schedule_work(&chip->work_torch);
+}
+
+/* flash */
+
+/* strobe pin config for lm3642*/
+static ssize_t lm3642_strobe_pin_store(struct device *dev,
+				       struct device_attribute *devAttr,
+				       const char *buf, size_t size)
+{
+	ssize_t ret;
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct lm3642_chip_data *chip =
+	    container_of(led_cdev, struct lm3642_chip_data, cdev_indicator);
+	unsigned int state;
+
+	ret = kstrtouint(buf, 10, &state);
+	if (ret)
+		goto out_strtoint;
+	if (state != 0)
+		state = 0x01 << STROBE_PIN_EN_SHIFT;
+
+	chip->strobe_pin = state;
+	ret = regmap_update_bits(chip->regmap, REG_ENABLE,
+				 STROBE_PIN_EN_MASK << STROBE_PIN_EN_SHIFT,
+				 state);
+	if (ret < 0)
+		goto out;
+
+	return size;
+out:
+	dev_err(chip->dev, "%s:i2c access fail to register\n", __func__);
+	return size;
+out_strtoint:
+	dev_err(chip->dev, "%s: fail to change str to int\n", __func__);
+	return size;
+}
+
+static DEVICE_ATTR(strobe_pin, 0666, NULL, lm3642_strobe_pin_store);
+
+static void lm3642_deferred_strobe_brightness_set(struct work_struct *work)
+{
+	struct lm3642_chip_data *chip =
+	    container_of(work, struct lm3642_chip_data, work_flash);
+
+	mutex_lock(&chip->lock);
+	lm3642_control(chip, chip->br_flash, MODES_FLASH);
+	mutex_unlock(&chip->lock);
+}
+
+static void lm3642_strobe_brightness_set(struct led_classdev *cdev,
+					 enum led_brightness brightness)
+{
+	struct lm3642_chip_data *chip =
+	    container_of(cdev, struct lm3642_chip_data, cdev_flash);
+
+	chip->br_flash = brightness;
+	schedule_work(&chip->work_flash);
+}
+
+/* indicator */
+static void lm3642_deferred_indicator_brightness_set(struct work_struct *work)
+{
+	struct lm3642_chip_data *chip =
+	    container_of(work, struct lm3642_chip_data, work_indicator);
+
+	mutex_lock(&chip->lock);
+	lm3642_control(chip, chip->br_indicator, MODES_INDIC);
+	mutex_unlock(&chip->lock);
+}
+
+static void lm3642_indicator_brightness_set(struct led_classdev *cdev,
+					    enum led_brightness brightness)
+{
+	struct lm3642_chip_data *chip =
+	    container_of(cdev, struct lm3642_chip_data, cdev_indicator);
+
+	chip->br_indicator = brightness;
+	schedule_work(&chip->work_indicator);
+}
+
+static const struct regmap_config lm3642_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = REG_MAX,
+};
+
+static int __devinit lm3642_probe(struct i2c_client *client,
+				  const struct i2c_device_id *id)
+{
+	struct lm3642_platform_data *pdata = client->dev.platform_data;
+	struct lm3642_chip_data *chip;
+
+	int err;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(&client->dev, "i2c functionality check fail.\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (pdata == NULL) {
+		dev_err(&client->dev, "needs Platform Data.\n");
+		return -ENODATA;
+	}
+
+	chip = devm_kzalloc(&client->dev,
+			    sizeof(struct lm3642_chip_data), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->dev = &client->dev;
+	chip->pdata = pdata;
+
+	chip->tx_pin = pdata->tx_pin;
+	chip->torch_pin = pdata->torch_pin;
+	chip->strobe_pin = pdata->strobe_pin;
+
+	chip->regmap = devm_regmap_init_i2c(client, &lm3642_regmap);
+	if (IS_ERR(chip->regmap)) {
+		err = PTR_ERR(chip->regmap);
+		dev_err(&client->dev, "Failed to allocate register map: %d\n",
+			err);
+		return err;
+	}
+
+	mutex_init(&chip->lock);
+	i2c_set_clientdata(client, chip);
+
+	err = lm3642_chip_init(chip);
+	if (err < 0)
+		goto err_out;
+
+	/* flash */
+	INIT_WORK(&chip->work_flash, lm3642_deferred_strobe_brightness_set);
+	chip->cdev_flash.name = "flash";
+	chip->cdev_flash.max_brightness = 16;
+	chip->cdev_flash.brightness_set = lm3642_strobe_brightness_set;
+	err = led_classdev_register((struct device *)
+				    &client->dev, &chip->cdev_flash);
+	if (err < 0) {
+		dev_err(chip->dev, "failed to register flash\n");
+		goto err_out;
+	}
+	err = device_create_file(chip->cdev_flash.dev, &dev_attr_strobe_pin);
+	if (err < 0) {
+		dev_err(chip->dev, "failed to create strobe-pin file\n");
+		goto err_create_flash_pin_file;
+	}
+
+	/* torch */
+	INIT_WORK(&chip->work_torch, lm3642_deferred_torch_brightness_set);
+	chip->cdev_torch.name = "torch";
+	chip->cdev_torch.max_brightness = 8;
+	chip->cdev_torch.brightness_set = lm3642_torch_brightness_set;
+	err = led_classdev_register((struct device *)
+				    &client->dev, &chip->cdev_torch);
+	if (err < 0) {
+		dev_err(chip->dev, "failed to register torch\n");
+		goto err_create_torch_file;
+	}
+	err = device_create_file(chip->cdev_torch.dev, &dev_attr_torch_pin);
+	if (err < 0) {
+		dev_err(chip->dev, "failed to create torch-pin file\n");
+		goto err_create_torch_pin_file;
+	}
+
+	/* indicator */
+	INIT_WORK(&chip->work_indicator,
+		  lm3642_deferred_indicator_brightness_set);
+	chip->cdev_indicator.name = "indicator";
+	chip->cdev_indicator.max_brightness = 8;
+	chip->cdev_indicator.brightness_set = lm3642_indicator_brightness_set;
+	err = led_classdev_register((struct device *)
+				    &client->dev, &chip->cdev_indicator);
+	if (err < 0) {
+		dev_err(chip->dev, "failed to register indicator\n");
+		goto err_create_indicator_file;
+	}
+
+	dev_info(&client->dev, "LM3642 is initialized\n");
+	return 0;
+
+err_create_indicator_file:
+	device_remove_file(chip->cdev_torch.dev, &dev_attr_torch_pin);
+err_create_torch_pin_file:
+	led_classdev_unregister(&chip->cdev_torch);
+err_create_torch_file:
+	device_remove_file(chip->cdev_flash.dev, &dev_attr_strobe_pin);
+err_create_flash_pin_file:
+	led_classdev_unregister(&chip->cdev_flash);
+err_out:
+	return err;
+}
+
+static int __devexit lm3642_remove(struct i2c_client *client)
+{
+	struct lm3642_chip_data *chip = i2c_get_clientdata(client);
+
+	led_classdev_unregister(&chip->cdev_indicator);
+	flush_work(&chip->work_indicator);
+	device_remove_file(chip->cdev_torch.dev, &dev_attr_torch_pin);
+	led_classdev_unregister(&chip->cdev_torch);
+	flush_work(&chip->work_torch);
+	device_remove_file(chip->cdev_flash.dev, &dev_attr_strobe_pin);
+	led_classdev_unregister(&chip->cdev_flash);
+	flush_work(&chip->work_flash);
+	regmap_write(chip->regmap, REG_ENABLE, 0);
+	return 0;
+}
+
+static const struct i2c_device_id lm3642_id[] = {
+	{LM3642_NAME, 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, lm3642_id);
+
+static struct i2c_driver lm3642_i2c_driver = {
+	.driver = {
+		   .name = LM3642_NAME,
+		   .owner = THIS_MODULE,
+		   .pm = NULL,
+		   },
+	.probe = lm3642_probe,
+	.remove = __devexit_p(lm3642_remove),
+	.id_table = lm3642_id,
+};
+
+module_i2c_driver(lm3642_i2c_driver);
+
+MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3642");
+MODULE_AUTHOR("Daniel Jeong <[e-mail]>");
+MODULE_AUTHOR("G.Shark Jeong <[e-mail]>");
+MODULE_LICENSE("GPL v2");

include/linux/platform_data/leds-lm3642.h

···
+/*
+* Copyright (C) 2012 Texas Instruments
+*
+* License Terms: GNU General Public License v2
+*
+* Simple driver for Texas Instruments LM3642 LED driver chip
+*
+* Author: G.Shark Jeong <[e-mail]>
+*         Daniel Jeong <[e-mail]>
+*/
+
+#ifndef __LINUX_LM3642_H
+#define __LINUX_LM3642_H
+
+#define LM3642_NAME "leds-lm3642"
+
+enum lm3642_torch_pin_enable {
+	LM3642_TORCH_PIN_DISABLE = 0x00,
+	LM3642_TORCH_PIN_ENABLE = 0x10,
+};
+
+enum lm3642_strobe_pin_enable {
+	LM3642_STROBE_PIN_DISABLE = 0x00,
+	LM3642_STROBE_PIN_ENABLE = 0x20,
+};
+
+enum lm3642_tx_pin_enable {
+	LM3642_TX_PIN_DISABLE = 0x00,
+	LM3642_TX_PIN_ENABLE = 0x40,
+};
+
+struct lm3642_platform_data {
+	enum lm3642_torch_pin_enable torch_pin;
+	enum lm3642_strobe_pin_enable strobe_pin;
+	enum lm3642_tx_pin_enable tx_pin;
+};
+
+#endif /* __LINUX_LM3642_H */