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 <gshark.jeong@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

4 files changed, 521 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 0dcb794df1fa..7cfa4d1555d9 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -63,6 +63,17 @@ config LEDS_LM3533
           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
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index b57a021d1fea..2ad9871becde 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_LEDS_BD2802)		+= leds-bd2802.o
 obj-$(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
diff --git a/drivers/leds/leds-lm3642.c b/drivers/leds/leds-lm3642.c
new file mode 100644
index 000000000000..924853b7922c
--- /dev/null
+++ b/drivers/leds/leds-lm3642.c
@@ -0,0 +1,471 @@
+/*
+* 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 <daniel.jeong@ti.com>");
+MODULE_AUTHOR("G.Shark Jeong <gshark.jeong@gmail.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/platform_data/leds-lm3642.h b/include/linux/platform_data/leds-lm3642.h
new file mode 100644
index 000000000000..72d6ee6ade57
--- /dev/null
+++ b/include/linux/platform_data/leds-lm3642.h
@@ -0,0 +1,38 @@
+/*
+* 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 <gshark.jeong@gmail.com>
+*         Daniel Jeong <daniel.jeong@ti.com>
+*/
+
+#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 */