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

[akpm@linux-foundation.org: code layout tweaks]
Signed-off-by: G.Shark Jeong <gshark.jeong@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Daniel Jeong <daniel.jeong@ti.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 447 insertions, 0 deletions

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index b9008b54ac5d..2b98fb8e711d 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -359,6 +359,15 @@ config BACKLIGHT_LM3630
         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
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index b0725313cd4d..a151378da45b 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_BACKLIGHT_HP680)	+= hp680_bl.o
 obj-$(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
diff --git a/drivers/video/backlight/lm3639_bl.c b/drivers/video/backlight/lm3639_bl.c
new file mode 100644
index 000000000000..c6915c6c3cd1
--- /dev/null
+++ b/drivers/video/backlight/lm3639_bl.c
@@ -0,0 +1,437 @@
+/*
+* 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 <daniel.jeong@ti.com>");
+MODULE_AUTHOR("G.Shark Jeong <gshark.jeong@gmail.com>");
+MODULE_LICENSE("GPL v2");