backlight: add new lm3639 backlight driver

This driver is a general version for LM3639 backlgiht + flash driver chip
of TI.

LM3639:
The LM3639 is a single chip LCD Display Backlight driver + white LED
Camera driver. Programming is done over an I2C compatible interface.
www.ti.com

[[e-mail]: code layout tweaks]
Signed-off-by: G.Shark Jeong <[e-mail]>
Cc: Richard Purdie <[e-mail]>
Cc: Daniel Jeong <[e-mail]>
Cc: Randy Dunlap <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/video/backlight/Kconfig

···
 	help
 	  This supports TI LM3630 Backlight Driver
 
+config BACKLIGHT_LM3639
+	tristate "Backlight Driver for LM3639"
+	depends on BACKLIGHT_CLASS_DEVICE && I2C
+	select REGMAP_I2C
+	select NEW_LEDS
+	select LEDS_CLASS
+	help
+	  This supports TI LM3639 Backlight + 1.5A Flash LED Driver
+
 config BACKLIGHT_LP855X
 	tristate "Backlight driver for TI LP855X"
 	depends on BACKLIGHT_CLASS_DEVICE && I2C

drivers/video/backlight/Makefile

···
 obj-$(CONFIG_BACKLIGHT_LM3533)	+= lm3533_bl.o
 obj-$(CONFIG_BACKLIGHT_LOCOMO)	+= locomolcd.o
 obj-$(CONFIG_BACKLIGHT_LM3630)	+= lm3630_bl.o
+obj-$(CONFIG_BACKLIGHT_LM3639)	+= lm3639_bl.o
 obj-$(CONFIG_BACKLIGHT_LP855X)	+= lp855x_bl.o
 obj-$(CONFIG_BACKLIGHT_OMAP1)	+= omap1_bl.o
 obj-$(CONFIG_BACKLIGHT_PANDORA)	+= pandora_bl.o

drivers/video/backlight/lm3639_bl.c

···
+/*
+* Simple driver for Texas Instruments LM3639 Backlight + Flash LED 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/slab.h>
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <linux/interrupt.h>
+#include <linux/regmap.h>
+#include <linux/platform_data/lm3639_bl.h>
+
+#define REG_DEV_ID	0x00
+#define REG_CHECKSUM	0x01
+#define REG_BL_CONF_1	0x02
+#define REG_BL_CONF_2	0x03
+#define REG_BL_CONF_3	0x04
+#define REG_BL_CONF_4	0x05
+#define REG_FL_CONF_1	0x06
+#define REG_FL_CONF_2	0x07
+#define REG_FL_CONF_3	0x08
+#define REG_IO_CTRL	0x09
+#define REG_ENABLE	0x0A
+#define REG_FLAG	0x0B
+#define REG_MAX		REG_FLAG
+
+struct lm3639_chip_data {
+	struct device *dev;
+	struct lm3639_platform_data *pdata;
+
+	struct backlight_device *bled;
+	struct led_classdev cdev_flash;
+	struct led_classdev cdev_torch;
+	struct regmap *regmap;
+
+	unsigned int bled_mode;
+	unsigned int bled_map;
+	unsigned int last_flag;
+};
+
+/* initialize chip */
+static int __devinit lm3639_chip_init(struct lm3639_chip_data *pchip)
+{
+	int ret;
+	unsigned int reg_val;
+	struct lm3639_platform_data *pdata = pchip->pdata;
+
+	/* input pins config. */
+	ret =
+	    regmap_update_bits(pchip->regmap, REG_BL_CONF_1, 0x08,
+			       pdata->pin_pwm);
+	if (ret < 0)
+		goto out;
+
+	reg_val = (pdata->pin_pwm & 0x40) | pdata->pin_strobe | pdata->pin_tx;
+	ret = regmap_update_bits(pchip->regmap, REG_IO_CTRL, 0x7C, reg_val);
+	if (ret < 0)
+		goto out;
+
+	/* init brightness */
+	ret = regmap_write(pchip->regmap, REG_BL_CONF_4, pdata->init_brt_led);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_write(pchip->regmap, REG_BL_CONF_3, pdata->init_brt_led);
+	if (ret < 0)
+		goto out;
+
+	/* output pins config. */
+	if (!pdata->init_brt_led)
+		reg_val = pdata->fled_pins | pdata->bled_pins;
+	else
+		reg_val = pdata->fled_pins | pdata->bled_pins | 0x01;
+
+	ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x79, reg_val);
+	if (ret < 0)
+		goto out;
+
+	return ret;
+out:
+	dev_err(pchip->dev, "i2c failed to access register\n");
+	return ret;
+}
+
+/* update and get brightness */
+static int lm3639_bled_update_status(struct backlight_device *bl)
+{
+	int ret;
+	unsigned int reg_val;
+	struct lm3639_chip_data *pchip = bl_get_data(bl);
+	struct lm3639_platform_data *pdata = pchip->pdata;
+
+	ret = regmap_read(pchip->regmap, REG_FLAG, &reg_val);
+	if (ret < 0)
+		goto out;
+
+	if (reg_val != 0)
+		dev_info(pchip->dev, "last flag is 0x%x\n", reg_val);
+
+	/* pwm control */
+	if (pdata->pin_pwm) {
+		if (pdata->pwm_set_intensity)
+			pdata->pwm_set_intensity(bl->props.brightness,
+						 pdata->max_brt_led);
+		else
+			dev_err(pchip->dev,
+				"No pwm control func. in plat-data\n");
+		return bl->props.brightness;
+	}
+
+	/* i2c control and set brigtness */
+	ret = regmap_write(pchip->regmap, REG_BL_CONF_4, bl->props.brightness);
+	if (ret < 0)
+		goto out;
+	ret = regmap_write(pchip->regmap, REG_BL_CONF_3, bl->props.brightness);
+	if (ret < 0)
+		goto out;
+
+	if (!bl->props.brightness)
+		ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x01, 0x00);
+	else
+		ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x01, 0x01);
+	if (ret < 0)
+		goto out;
+
+	return bl->props.brightness;
+out:
+	dev_err(pchip->dev, "i2c failed to access registers\n");
+	return bl->props.brightness;
+}
+
+static int lm3639_bled_get_brightness(struct backlight_device *bl)
+{
+	int ret;
+	unsigned int reg_val;
+	struct lm3639_chip_data *pchip = bl_get_data(bl);
+	struct lm3639_platform_data *pdata = pchip->pdata;
+
+	if (pdata->pin_pwm) {
+		if (pdata->pwm_get_intensity)
+			bl->props.brightness = pdata->pwm_get_intensity();
+		else
+			dev_err(pchip->dev,
+				"No pwm control func. in plat-data\n");
+		return bl->props.brightness;
+	}
+
+	ret = regmap_read(pchip->regmap, REG_BL_CONF_1, &reg_val);
+	if (ret < 0)
+		goto out;
+	if (reg_val & 0x10)
+		ret = regmap_read(pchip->regmap, REG_BL_CONF_4, &reg_val);
+	else
+		ret = regmap_read(pchip->regmap, REG_BL_CONF_3, &reg_val);
+	if (ret < 0)
+		goto out;
+	bl->props.brightness = reg_val;
+
+	return bl->props.brightness;
+out:
+	dev_err(pchip->dev, "i2c failed to access register\n");
+	return bl->props.brightness;
+}
+
+static const struct backlight_ops lm3639_bled_ops = {
+	.options = BL_CORE_SUSPENDRESUME,
+	.update_status = lm3639_bled_update_status,
+	.get_brightness = lm3639_bled_get_brightness,
+};
+
+/* backlight mapping mode */
+static ssize_t lm3639_bled_mode_store(struct device *dev,
+				      struct device_attribute *devAttr,
+				      const char *buf, size_t size)
+{
+	ssize_t ret;
+	struct lm3639_chip_data *pchip = dev_get_drvdata(dev);
+	unsigned int state;
+
+	ret = kstrtouint(buf, 10, &state);
+	if (ret)
+		goto out_input;
+
+	if (!state)
+		ret =
+		    regmap_update_bits(pchip->regmap, REG_BL_CONF_1, 0x10,
+				       0x00);
+	else
+		ret =
+		    regmap_update_bits(pchip->regmap, REG_BL_CONF_1, 0x10,
+				       0x10);
+
+	if (ret < 0)
+		goto out;
+
+	return size;
+
+out:
+	dev_err(pchip->dev, "%s:i2c access fail to register\n", __func__);
+	return size;
+
+out_input:
+	dev_err(pchip->dev, "%s:input conversion fail\n", __func__);
+	return size;
+
+}
+
+static DEVICE_ATTR(bled_mode, 0666, NULL, lm3639_bled_mode_store);
+
+/* torch */
+static void lm3639_torch_brightness_set(struct led_classdev *cdev,
+					enum led_brightness brightness)
+{
+	int ret;
+	unsigned int reg_val;
+	struct lm3639_chip_data *pchip;
+
+	pchip = container_of(cdev, struct lm3639_chip_data, cdev_torch);
+
+	ret = regmap_read(pchip->regmap, REG_FLAG, &reg_val);
+	if (ret < 0)
+		goto out;
+	if (reg_val != 0)
+		dev_info(pchip->dev, "last flag is 0x%x\n", reg_val);
+
+	/* brightness 0 means off state */
+	if (!brightness) {
+		ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x06, 0x00);
+		if (ret < 0)
+			goto out;
+		return;
+	}
+
+	ret = regmap_update_bits(pchip->regmap,
+				 REG_FL_CONF_1, 0x70, (brightness - 1) << 4);
+	if (ret < 0)
+		goto out;
+	ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x06, 0x02);
+	if (ret < 0)
+		goto out;
+
+	return;
+out:
+	dev_err(pchip->dev, "i2c failed to access register\n");
+	return;
+}
+
+/* flash */
+static void lm3639_flash_brightness_set(struct led_classdev *cdev,
+					enum led_brightness brightness)
+{
+	int ret;
+	unsigned int reg_val;
+	struct lm3639_chip_data *pchip;
+
+	pchip = container_of(cdev, struct lm3639_chip_data, cdev_flash);
+
+	ret = regmap_read(pchip->regmap, REG_FLAG, &reg_val);
+	if (ret < 0)
+		goto out;
+	if (reg_val != 0)
+		dev_info(pchip->dev, "last flag is 0x%x\n", reg_val);
+
+	/* torch off before flash control */
+	ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x06, 0x00);
+	if (ret < 0)
+		goto out;
+
+	/* brightness 0 means off state */
+	if (!brightness)
+		return;
+
+	ret = regmap_update_bits(pchip->regmap,
+				 REG_FL_CONF_1, 0x0F, brightness - 1);
+	if (ret < 0)
+		goto out;
+	ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x06, 0x06);
+	if (ret < 0)
+		goto out;
+
+	return;
+out:
+	dev_err(pchip->dev, "i2c failed to access register\n");
+	return;
+}
+
+static const struct regmap_config lm3639_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = REG_MAX,
+};
+
+static int __devinit lm3639_probe(struct i2c_client *client,
+				  const struct i2c_device_id *id)
+{
+	int ret;
+	struct lm3639_chip_data *pchip;
+	struct lm3639_platform_data *pdata = client->dev.platform_data;
+	struct backlight_properties props;
+
+	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;
+	}
+
+	pchip = devm_kzalloc(&client->dev,
+			     sizeof(struct lm3639_chip_data), GFP_KERNEL);
+	if (!pchip)
+		return -ENOMEM;
+
+	pchip->pdata = pdata;
+	pchip->dev = &client->dev;
+
+	pchip->regmap = devm_regmap_init_i2c(client, &lm3639_regmap);
+	if (IS_ERR(pchip->regmap)) {
+		ret = PTR_ERR(pchip->regmap);
+		dev_err(&client->dev, "fail : allocate register map: %d\n",
+			ret);
+		return ret;
+	}
+	i2c_set_clientdata(client, pchip);
+
+	/* chip initialize */
+	ret = lm3639_chip_init(pchip);
+	if (ret < 0) {
+		dev_err(&client->dev, "fail : chip init\n");
+		goto err_out;
+	}
+
+	/* backlight */
+	props.type = BACKLIGHT_RAW;
+	props.brightness = pdata->init_brt_led;
+	props.max_brightness = pdata->max_brt_led;
+	pchip->bled =
+	    backlight_device_register("lm3639_bled", pchip->dev, pchip,
+				      &lm3639_bled_ops, &props);
+	if (IS_ERR(pchip->bled)) {
+		dev_err(&client->dev, "fail : backlight register\n");
+		ret = -EIO;
+		goto err_out;
+	}
+
+	ret = device_create_file(&(pchip->bled->dev), &dev_attr_bled_mode);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed : add sysfs entries\n");
+		ret = -EIO;
+		goto err_bled_mode;
+	}
+
+	/* flash */
+	pchip->cdev_flash.name = "lm3639_flash";
+	pchip->cdev_flash.max_brightness = 16;
+	pchip->cdev_flash.brightness_set = lm3639_flash_brightness_set;
+	ret = led_classdev_register((struct device *)
+				    &client->dev, &pchip->cdev_flash);
+	if (ret < 0) {
+		dev_err(&client->dev, "fail : flash register\n");
+		ret = -EIO;
+		goto err_flash;
+	}
+
+	/* torch */
+	pchip->cdev_torch.name = "lm3639_torch";
+	pchip->cdev_torch.max_brightness = 8;
+	pchip->cdev_torch.brightness_set = lm3639_torch_brightness_set;
+	ret = led_classdev_register((struct device *)
+				    &client->dev, &pchip->cdev_torch);
+	if (ret < 0) {
+		dev_err(&client->dev, "fail : torch register\n");
+		ret = -EIO;
+		goto err_torch;
+	}
+
+	return 0;
+
+err_torch:
+	led_classdev_unregister(&pchip->cdev_flash);
+err_flash:
+	device_remove_file(&(pchip->bled->dev), &dev_attr_bled_mode);
+err_bled_mode:
+	backlight_device_unregister(pchip->bled);
+err_out:
+	return ret;
+}
+
+static int __devexit lm3639_remove(struct i2c_client *client)
+{
+	struct lm3639_chip_data *pchip = i2c_get_clientdata(client);
+
+	regmap_write(pchip->regmap, REG_ENABLE, 0x00);
+
+	if (&pchip->cdev_torch)
+		led_classdev_unregister(&pchip->cdev_torch);
+	if (&pchip->cdev_flash)
+		led_classdev_unregister(&pchip->cdev_flash);
+	if (pchip->bled) {
+		device_remove_file(&(pchip->bled->dev), &dev_attr_bled_mode);
+		backlight_device_unregister(pchip->bled);
+	}
+	return 0;
+}
+
+static const struct i2c_device_id lm3639_id[] = {
+	{LM3639_NAME, 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, lm3639_id);
+static struct i2c_driver lm3639_i2c_driver = {
+	.driver = {
+		   .name = LM3639_NAME,
+		   },
+	.probe = lm3639_probe,
+	.remove = __devexit_p(lm3639_remove),
+	.id_table = lm3639_id,
+};
+
+module_i2c_driver(lm3639_i2c_driver);
+
+MODULE_DESCRIPTION("Texas Instruments Backlight+Flash LED driver for LM3639");
+MODULE_AUTHOR("Daniel Jeong <[e-mail]>");
+MODULE_AUTHOR("G.Shark Jeong <[e-mail]>");
+MODULE_LICENSE("GPL v2");

include/linux/platform_data/lm3639_bl.h

···
+/*
+* Simple driver for Texas Instruments LM3630 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.
+*
+*/
+
+#ifndef __LINUX_LM3639_H
+#define __LINUX_LM3639_H
+
+#define LM3639_NAME "lm3639_bl"
+
+enum lm3639_pwm {
+	LM3639_PWM_DISABLE = 0x00,
+	LM3639_PWM_EN_ACTLOW = 0x48,
+	LM3639_PWM_EN_ACTHIGH = 0x40,
+};
+
+enum lm3639_strobe {
+	LM3639_STROBE_DISABLE = 0x00,
+	LM3639_STROBE_EN_ACTLOW = 0x10,
+	LM3639_STROBE_EN_ACTHIGH = 0x30,
+};
+
+enum lm3639_txpin {
+	LM3639_TXPIN_DISABLE = 0x00,
+	LM3639_TXPIN_EN_ACTLOW = 0x04,
+	LM3639_TXPIN_EN_ACTHIGH = 0x0C,
+};
+
+enum lm3639_fleds {
+	LM3639_FLED_DIASBLE_ALL = 0x00,
+	LM3639_FLED_EN_1 = 0x40,
+	LM3639_FLED_EN_2 = 0x20,
+	LM3639_FLED_EN_ALL = 0x60,
+};
+
+enum lm3639_bleds {
+	LM3639_BLED_DIASBLE_ALL = 0x00,
+	LM3639_BLED_EN_1 = 0x10,
+	LM3639_BLED_EN_2 = 0x08,
+	LM3639_BLED_EN_ALL = 0x18,
+};
+enum lm3639_bled_mode {
+	LM3639_BLED_MODE_EXPONETIAL = 0x00,
+	LM3639_BLED_MODE_LINEAR = 0x10,
+};
+
+struct lm3639_platform_data {
+	unsigned int max_brt_led;
+	unsigned int init_brt_led;
+
+	/* input pins */
+	enum lm3639_pwm pin_pwm;
+	enum lm3639_strobe pin_strobe;
+	enum lm3639_txpin pin_tx;
+
+	/* output pins */
+	enum lm3639_fleds fled_pins;
+	enum lm3639_bleds bled_pins;
+	enum lm3639_bled_mode bled_mode;
+
+	void (*pwm_set_intensity) (int brightness, int max_brightness);
+	int (*pwm_get_intensity) (void);
+};
+#endif /* __LINUX_LM3639_H */