leds: Add LED driver for lm3556 chip

LM3556 :
The LM3556 is a 4 MHz fixed-frequency synchronous boost
converter plus 1.5A constant current driver for a high-current white LED.
Datasheet: www.national.com/ds/LM/LM3556.pdf

Tested on OMAP4430

(bryan.wu@canonical.com: use module_i2c_driver() rather than
lm3556_init/lm3556_exit for code simplicity; fixed some typo
pointed out by Rob Landley)

Signed-off-by: G.Shark Jeong <gshark.jeong@gmail.com>
Reviewed-by: Axel Lin <axel.lin@gmail.com>
Reviewed-by: Kim, Milo <Milo.Kim@ti.com>
Acked-by: Rob Landley <rob@landley.net>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

3 files changed, 521 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 52f1d456f3d2..f028f0348e83 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -415,6 +415,14 @@ config LEDS_MAX8997
 	  This option enables support for on-chip LED drivers on
 	  MAXIM MAX8997 PMIC.
 
+config LEDS_LM3556
+	tristate "LED support for LM3556 Chip"
+	depends on LEDS_CLASS && I2C
+	select REGMAP_I2C
+	help
+	  This option enables support for LEDs connected to LM3556.
+	  LM3556 includes Torch, Flash and Indicator functions.
+
 config LEDS_OT200
 	tristate "LED support for the Bachmann OT200"
 	depends on LEDS_CLASS && HAS_IOMEM
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 9112d518f9d4..5eebd7bce4be 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_LEDS_NETXBIG)		+= leds-netxbig.o
 obj-$(CONFIG_LEDS_ASIC3)		+= leds-asic3.o
 obj-$(CONFIG_LEDS_RENESAS_TPU)		+= leds-renesas-tpu.o
 obj-$(CONFIG_LEDS_MAX8997)		+= leds-max8997.o
+obj-$(CONFIG_LEDS_LM3556)		+= leds-lm3556.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o
diff --git a/drivers/leds/leds-lm3556.c b/drivers/leds/leds-lm3556.c
new file mode 100644
index 000000000000..3062abd9a532
--- /dev/null
+++ b/drivers/leds/leds-lm3556.c
@@ -0,0 +1,512 @@
+/*
+ * Simple driver for Texas Instruments LM3556 LED Flash driver chip (Rev0x03)
+ * 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.
+ *
+ * Please refer Documentation/leds/leds-lm3556.txt file.
+ */
+#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/platform_data/leds-lm3556.h>
+
+#define REG_FILT_TIME			(0x0)
+#define REG_IVFM_MODE			(0x1)
+#define REG_NTC				(0x2)
+#define REG_INDIC_TIME			(0x3)
+#define REG_INDIC_BLINK			(0x4)
+#define REG_INDIC_PERIOD		(0x5)
+#define REG_TORCH_TIME			(0x6)
+#define REG_CONF			(0x7)
+#define REG_FLASH			(0x8)
+#define REG_I_CTRL			(0x9)
+#define REG_ENABLE			(0xA)
+#define REG_FLAG			(0xB)
+#define REG_MAX				(0xB)
+
+#define IVFM_FILTER_TIME_SHIFT		(3)
+#define UVLO_EN_SHIFT			(7)
+#define HYSTERSIS_SHIFT			(5)
+#define IVM_D_TH_SHIFT			(2)
+#define IVFM_ADJ_MODE_SHIFT		(0)
+#define NTC_EVENT_LVL_SHIFT		(5)
+#define NTC_TRIP_TH_SHIFT		(2)
+#define NTC_BIAS_I_LVL_SHIFT		(0)
+#define INDIC_RAMP_UP_TIME_SHIFT	(3)
+#define INDIC_RAMP_DN_TIME_SHIFT	(0)
+#define INDIC_N_BLANK_SHIFT		(4)
+#define INDIC_PULSE_TIME_SHIFT		(0)
+#define INDIC_N_PERIOD_SHIFT		(0)
+#define TORCH_RAMP_UP_TIME_SHIFT	(3)
+#define TORCH_RAMP_DN_TIME_SHIFT	(0)
+#define STROBE_USUAGE_SHIFT		(7)
+#define STROBE_PIN_POLARITY_SHIFT	(6)
+#define TORCH_PIN_POLARITY_SHIFT	(5)
+#define TX_PIN_POLARITY_SHIFT		(4)
+#define TX_EVENT_LVL_SHIFT		(3)
+#define IVFM_EN_SHIFT			(2)
+#define NTC_MODE_SHIFT			(1)
+#define INDIC_MODE_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 NTC_EN_SHIFT			(7)
+#define TX_PIN_EN_SHIFT			(6)
+#define STROBE_PIN_EN_SHIFT		(5)
+#define TORCH_PIN_EN_SHIFT		(4)
+#define PRECHG_MODE_EN_SHIFT		(3)
+#define PASS_MODE_ONLY_EN_SHIFT		(2)
+#define MODE_BITS_SHIFT			(0)
+
+#define IVFM_FILTER_TIME_MASK		(0x3)
+#define UVLO_EN_MASK			(0x1)
+#define HYSTERSIS_MASK			(0x3)
+#define IVM_D_TH_MASK			(0x7)
+#define IVFM_ADJ_MODE_MASK		(0x3)
+#define NTC_EVENT_LVL_MASK		(0x1)
+#define NTC_TRIP_TH_MASK		(0x7)
+#define NTC_BIAS_I_LVL_MASK		(0x3)
+#define INDIC_RAMP_UP_TIME_MASK		(0x7)
+#define INDIC_RAMP_DN_TIME_MASK		(0x7)
+#define INDIC_N_BLANK_MASK		(0x7)
+#define INDIC_PULSE_TIME_MASK		(0x7)
+#define INDIC_N_PERIOD_MASK		(0x7)
+#define TORCH_RAMP_UP_TIME_MASK		(0x7)
+#define TORCH_RAMP_DN_TIME_MASK		(0x7)
+#define STROBE_USUAGE_MASK		(0x1)
+#define STROBE_PIN_POLARITY_MASK	(0x1)
+#define TORCH_PIN_POLARITY_MASK		(0x1)
+#define TX_PIN_POLARITY_MASK		(0x1)
+#define TX_EVENT_LVL_MASK		(0x1)
+#define IVFM_EN_MASK			(0x1)
+#define NTC_MODE_MASK			(0x1)
+#define INDIC_MODE_MASK			(0x1)
+#define INDUCTOR_I_LIMIT_MASK		(0x3)
+#define FLASH_RAMP_TIME_MASK		(0x7)
+#define FLASH_TOUT_TIME_MASK		(0x7)
+#define TORCH_I_MASK			(0x7)
+#define FLASH_I_MASK			(0xF)
+#define NTC_EN_MASK			(0x1)
+#define TX_PIN_EN_MASK			(0x1)
+#define STROBE_PIN_EN_MASK		(0x1)
+#define TORCH_PIN_EN_MASK		(0x1)
+#define PRECHG_MODE_EN_MASK		(0x1)
+#define PASS_MODE_ONLY_EN_MASK		(0x1)
+#define MODE_BITS_MASK			(0x13)
+#define EX_PIN_CONTROL_MASK		(0xF1)
+#define EX_PIN_ENABLE_MASK		(0x70)
+
+enum lm3556_indic_pulse_time {
+	PULSE_TIME_0_MS = 0,
+	PULSE_TIME_32_MS,
+	PULSE_TIME_64_MS,
+	PULSE_TIME_92_MS,
+	PULSE_TIME_128_MS,
+	PULSE_TIME_160_MS,
+	PULSE_TIME_196_MS,
+	PULSE_TIME_224_MS,
+	PULSE_TIME_256_MS,
+	PULSE_TIME_288_MS,
+	PULSE_TIME_320_MS,
+	PULSE_TIME_352_MS,
+	PULSE_TIME_384_MS,
+	PULSE_TIME_416_MS,
+	PULSE_TIME_448_MS,
+	PULSE_TIME_480_MS,
+};
+
+enum lm3556_indic_n_blank {
+	INDIC_N_BLANK_0 = 0,
+	INDIC_N_BLANK_1,
+	INDIC_N_BLANK_2,
+	INDIC_N_BLANK_3,
+	INDIC_N_BLANK_4,
+	INDIC_N_BLANK_5,
+	INDIC_N_BLANK_6,
+	INDIC_N_BLANK_7,
+	INDIC_N_BLANK_8,
+	INDIC_N_BLANK_9,
+	INDIC_N_BLANK_10,
+	INDIC_N_BLANK_11,
+	INDIC_N_BLANK_12,
+	INDIC_N_BLANK_13,
+	INDIC_N_BLANK_14,
+	INDIC_N_BLANK_15,
+};
+
+enum lm3556_indic_period {
+	INDIC_PERIOD_0 = 0,
+	INDIC_PERIOD_1,
+	INDIC_PERIOD_2,
+	INDIC_PERIOD_3,
+	INDIC_PERIOD_4,
+	INDIC_PERIOD_5,
+	INDIC_PERIOD_6,
+	INDIC_PERIOD_7,
+};
+
+enum lm3556_mode {
+	MODES_STASNDBY = 0,
+	MODES_INDIC,
+	MODES_TORCH,
+	MODES_FLASH
+};
+
+#define INDIC_PATTERN_SIZE 4
+
+struct indicator {
+	u8 blinking;
+	u8 period_cnt;
+};
+
+struct lm3556_chip_data {
+	struct device *dev;
+
+	struct led_classdev cdev_flash;
+	struct led_classdev cdev_torch;
+	struct led_classdev cdev_indicator;
+
+	struct lm3556_platform_data *pdata;
+	struct regmap *regmap;
+	struct mutex lock;
+
+	unsigned int last_flag;
+};
+
+/* indicator pattern */
+static struct indicator indicator_pattern[INDIC_PATTERN_SIZE] = {
+	[0] = {(INDIC_N_BLANK_1 << INDIC_N_BLANK_SHIFT)
+	       | PULSE_TIME_32_MS, INDIC_PERIOD_1},
+	[1] = {(INDIC_N_BLANK_15 << INDIC_N_BLANK_SHIFT)
+	       | PULSE_TIME_32_MS, INDIC_PERIOD_2},
+	[2] = {(INDIC_N_BLANK_10 << INDIC_N_BLANK_SHIFT)
+	       | PULSE_TIME_32_MS, INDIC_PERIOD_4},
+	[3] = {(INDIC_N_BLANK_5 << INDIC_N_BLANK_SHIFT)
+	       | PULSE_TIME_32_MS, INDIC_PERIOD_7},
+};
+
+/* chip initialize */
+static int __devinit lm3556_chip_init(struct lm3556_chip_data *chip)
+{
+	unsigned int reg_val;
+	int ret;
+	struct lm3556_platform_data *pdata = chip->pdata;
+
+	/* set config register */
+	ret = regmap_read(chip->regmap, REG_CONF, &reg_val);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to read REG_CONF Register\n");
+		goto out;
+	}
+
+	reg_val &= (~EX_PIN_CONTROL_MASK);
+	reg_val |= ((pdata->torch_pin_polarity & 0x01)
+		    << TORCH_PIN_POLARITY_SHIFT);
+	reg_val |= ((pdata->strobe_usuage & 0x01) << STROBE_USUAGE_SHIFT);
+	reg_val |= ((pdata->strobe_pin_polarity & 0x01)
+		    << STROBE_PIN_POLARITY_SHIFT);
+	reg_val |= ((pdata->tx_pin_polarity & 0x01) << TX_PIN_POLARITY_SHIFT);
+	reg_val |= ((pdata->indicator_mode & 0x01) << INDIC_MODE_SHIFT);
+
+	ret = regmap_write(chip->regmap, REG_CONF, reg_val);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to write REG_CONF Regisgter\n");
+		goto out;
+	}
+
+	/* set enable register */
+	ret = regmap_read(chip->regmap, REG_ENABLE, &reg_val);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to read REG_ENABLE Register\n");
+		goto out;
+	}
+
+	reg_val &= (~EX_PIN_ENABLE_MASK);
+	reg_val |= ((pdata->torch_pin_en & 0x01) << TORCH_PIN_EN_SHIFT);
+	reg_val |= ((pdata->strobe_pin_en & 0x01) << STROBE_PIN_EN_SHIFT);
+	reg_val |= ((pdata->tx_pin_en & 0x01) << TX_PIN_EN_SHIFT);
+
+	ret = regmap_write(chip->regmap, REG_ENABLE, reg_val);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to write REG_ENABLE Regisgter\n");
+		goto out;
+	}
+
+out:
+	return ret;
+}
+
+/* chip control */
+static int lm3556_control(struct lm3556_chip_data *chip,
+			  u8 brightness, enum lm3556_mode opmode)
+{
+	int ret;
+	struct lm3556_platform_data *pdata = chip->pdata;
+
+	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 (pdata->torch_pin_en)
+			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);
+		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:
+		if (pdata->torch_pin_en)
+			opmode |= (TORCH_PIN_EN_MASK << TORCH_PIN_EN_SHIFT);
+		break;
+
+	default:
+		return ret;
+	}
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to write REG_I_CTRL Register\n");
+		goto out;
+	}
+	ret = regmap_update_bits(chip->regmap, REG_ENABLE,
+				 MODE_BITS_MASK << MODE_BITS_SHIFT,
+				 opmode << MODE_BITS_SHIFT);
+
+out:
+	return ret;
+}
+
+/* torch */
+static void lm3556_torch_brightness_set(struct led_classdev *cdev,
+					enum led_brightness brightness)
+{
+	struct lm3556_chip_data *chip =
+	    container_of(cdev, struct lm3556_chip_data, cdev_torch);
+
+	mutex_lock(&chip->lock);
+	lm3556_control(chip, brightness, MODES_TORCH);
+	mutex_unlock(&chip->lock);
+}
+
+/* flash */
+static void lm3556_strobe_brightness_set(struct led_classdev *cdev,
+					 enum led_brightness brightness)
+{
+	struct lm3556_chip_data *chip =
+	    container_of(cdev, struct lm3556_chip_data, cdev_flash);
+
+	mutex_lock(&chip->lock);
+	lm3556_control(chip, brightness, MODES_FLASH);
+	mutex_unlock(&chip->lock);
+}
+
+/* indicator */
+static void lm3556_indicator_brightness_set(struct led_classdev *cdev,
+					    enum led_brightness brightness)
+{
+	struct lm3556_chip_data *chip =
+	    container_of(cdev, struct lm3556_chip_data, cdev_indicator);
+
+	mutex_lock(&chip->lock);
+	lm3556_control(chip, brightness, MODES_INDIC);
+	mutex_unlock(&chip->lock);
+}
+
+/* indicator pattern */
+static ssize_t lm3556_indicator_pattern_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 lm3556_chip_data *chip =
+	    container_of(led_cdev, struct lm3556_chip_data, cdev_indicator);
+	unsigned int state;
+
+	ret = kstrtouint(buf, 10, &state);
+	if (ret)
+		goto out;
+	if (state > INDIC_PATTERN_SIZE - 1)
+		state = INDIC_PATTERN_SIZE - 1;
+
+	ret = regmap_write(chip->regmap, REG_INDIC_BLINK,
+			   indicator_pattern[state].blinking);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to write REG_ENABLE Regisgter\n");
+		goto out;
+	}
+
+	ret = regmap_write(chip->regmap, REG_INDIC_PERIOD,
+			   indicator_pattern[state].period_cnt);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to write REG_ENABLE Regisgter\n");
+		goto out;
+	}
+
+	return size;
+out:
+	dev_err(chip->dev, "Indicator pattern doesn't saved\n");
+	return size;
+}
+
+static DEVICE_ATTR(pattern, 0666, NULL, lm3556_indicator_pattern_store);
+
+static const struct regmap_config lm3556_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = REG_MAX,
+};
+
+/* module initialize */
+static int __devinit lm3556_probe(struct i2c_client *client,
+				  const struct i2c_device_id *id)
+{
+	struct lm3556_platform_data *pdata = client->dev.platform_data;
+	struct lm3556_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 lm3556_chip_data),
+			 GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->dev = &client->dev;
+	chip->pdata = pdata;
+
+	chip->regmap = devm_regmap_init_i2c(client, &lm3556_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 = lm3556_chip_init(chip);
+	if (err < 0)
+		goto err_out;
+
+	/* flash */
+	chip->cdev_flash.name = "flash";
+	chip->cdev_flash.max_brightness = 16;
+	chip->cdev_flash.brightness_set = lm3556_strobe_brightness_set;
+	err = led_classdev_register((struct device *)
+				    &client->dev, &chip->cdev_flash);
+	if (err < 0)
+		goto err_out;
+	/* torch */
+	chip->cdev_torch.name = "torch";
+	chip->cdev_torch.max_brightness = 8;
+	chip->cdev_torch.brightness_set = lm3556_torch_brightness_set;
+	err = led_classdev_register((struct device *)
+				    &client->dev, &chip->cdev_torch);
+	if (err < 0)
+		goto err_create_torch_file;
+	/* indicator */
+	chip->cdev_indicator.name = "indicator";
+	chip->cdev_indicator.max_brightness = 8;
+	chip->cdev_indicator.brightness_set = lm3556_indicator_brightness_set;
+	err = led_classdev_register((struct device *)
+				    &client->dev, &chip->cdev_indicator);
+	if (err < 0)
+		goto err_create_indicator_file;
+
+	err = device_create_file(chip->cdev_indicator.dev, &dev_attr_pattern);
+	if (err < 0)
+		goto err_create_pattern_file;
+
+	dev_info(&client->dev, "LM3556 is initialized\n");
+	return 0;
+
+err_create_pattern_file:
+	led_classdev_unregister(&chip->cdev_indicator);
+err_create_indicator_file:
+	led_classdev_unregister(&chip->cdev_torch);
+err_create_torch_file:
+	led_classdev_unregister(&chip->cdev_flash);
+err_out:
+	return err;
+}
+
+static int __devexit lm3556_remove(struct i2c_client *client)
+{
+	struct lm3556_chip_data *chip = i2c_get_clientdata(client);
+
+	device_remove_file(chip->cdev_indicator.dev, &dev_attr_pattern);
+	led_classdev_unregister(&chip->cdev_indicator);
+	led_classdev_unregister(&chip->cdev_torch);
+	led_classdev_unregister(&chip->cdev_flash);
+	regmap_write(chip->regmap, REG_ENABLE, 0);
+	return 0;
+}
+
+static const struct i2c_device_id lm3556_id[] = {
+	{LM3556_NAME, 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, lm3556_id);
+
+static struct i2c_driver lm3556_i2c_driver = {
+	.driver = {
+		   .name = LM3556_NAME,
+		   .owner = THIS_MODULE,
+		   .pm = NULL,
+		   },
+	.probe = lm3556_probe,
+	.remove = __devexit_p(lm3556_remove),
+	.id_table = lm3556_id,
+};
+
+module_i2c_driver(lm3556_i2c_driver);
+
+MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3556");
+MODULE_AUTHOR("Daniel Jeong <daniel.jeong@ti.com>");
+MODULE_AUTHOR("G.Shark Jeong <gshark.jeong@gmail.com>");
+MODULE_LICENSE("GPL v2");