Commit b1e6b706 authored by Shreshtha Kumar Sahu's avatar Shreshtha Kumar Sahu Committed by Linus Torvalds
Browse files

leds: add driver for LM3530 ALS 



Simple backlight driver for National Semiconductor LM3530.  Presently only
manual mode is supported, PWM and ALS support to be added.

Signed-off-by: default avatarShreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 551ea738

drivers/leds/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -34,6 +34,16 @@ config LEDS_ATMEL_PWM 
	  This option enables support for LEDs driven using outputs

	  of the dedicated PWM controller found on newer Atmel SOCs.



config LEDS_LM3530

	tristate "LCD Backlight driver for LM3530"

	depends on LEDS_CLASS

	depends on I2C

	help

	  This option enables support for the LCD backlight using

	  LM3530 ambient light sensor chip. This ALS chip can be

	  controlled manually or using PWM input or using ambient

	  light automatically.



config LEDS_LOCOMO

	tristate "LED Support for Locomo device"

	depends on LEDS_CLASS

drivers/leds/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ obj-$(CONFIG_LEDS_88PM860X) += leds-88pm860x.o 
obj-$(CONFIG_LEDS_ATMEL_PWM)		+= leds-atmel-pwm.o

obj-$(CONFIG_LEDS_BD2802)		+= leds-bd2802.o

obj-$(CONFIG_LEDS_LOCOMO)		+= leds-locomo.o

obj-$(CONFIG_LEDS_LM3530)		+= leds-lm3530.o

obj-$(CONFIG_LEDS_MIKROTIK_RB532)	+= leds-rb532.o

obj-$(CONFIG_LEDS_S3C24XX)		+= leds-s3c24xx.o

obj-$(CONFIG_LEDS_AMS_DELTA)		+= leds-ams-delta.o

drivers/leds/leds-lm3530.c

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/*

 * Copyright (C) 2011 ST-Ericsson SA.

 * Copyright (C) 2009 Motorola, Inc.

 *

 * License Terms: GNU General Public License v2

 *

 * Simple driver for National Semiconductor LM3530 Backlight driver chip

 *

 * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>

 * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>

 */



#include <linux/i2c.h>

#include <linux/leds.h>

#include <linux/slab.h>

#include <linux/platform_device.h>

#include <linux/input.h>

#include <linux/led-lm3530.h>

#include <linux/types.h>



#define LM3530_LED_DEV "lcd-backlight"

#define LM3530_NAME "lm3530-led"



#define LM3530_GEN_CONFIG		0x10

#define LM3530_ALS_CONFIG		0x20

#define LM3530_BRT_RAMP_RATE		0x30

#define LM3530_ALS_ZONE_REG		0x40

#define LM3530_ALS_IMP_SELECT		0x41

#define LM3530_BRT_CTRL_REG		0xA0

#define LM3530_ALS_ZB0_REG		0x60

#define LM3530_ALS_ZB1_REG		0x61

#define LM3530_ALS_ZB2_REG		0x62

#define LM3530_ALS_ZB3_REG		0x63

#define LM3530_ALS_Z0T_REG		0x70

#define LM3530_ALS_Z1T_REG		0x71

#define LM3530_ALS_Z2T_REG		0x72

#define LM3530_ALS_Z3T_REG		0x73

#define LM3530_ALS_Z4T_REG		0x74

#define LM3530_REG_MAX			15



/* General Control Register */

#define LM3530_EN_I2C_SHIFT		(0)

#define LM3530_RAMP_LAW_SHIFT		(1)

#define LM3530_MAX_CURR_SHIFT		(2)

#define LM3530_EN_PWM_SHIFT		(5)

#define LM3530_PWM_POL_SHIFT		(6)

#define LM3530_EN_PWM_SIMPLE_SHIFT	(7)



#define LM3530_ENABLE_I2C		(1 << LM3530_EN_I2C_SHIFT)

#define LM3530_ENABLE_PWM		(1 << LM3530_EN_PWM_SHIFT)

#define LM3530_POL_LOW			(1 << LM3530_PWM_POL_SHIFT)

#define LM3530_ENABLE_PWM_SIMPLE	(1 << LM3530_EN_PWM_SIMPLE_SHIFT)



/* ALS Config Register Options */

#define LM3530_ALS_AVG_TIME_SHIFT	(0)

#define LM3530_EN_ALS_SHIFT		(3)

#define LM3530_ALS_SEL_SHIFT		(5)



#define LM3530_ENABLE_ALS		(3 << LM3530_EN_ALS_SHIFT)



/* Brightness Ramp Rate Register */

#define LM3530_BRT_RAMP_FALL_SHIFT	(0)

#define LM3530_BRT_RAMP_RISE_SHIFT	(3)



/* ALS Resistor Select */

#define LM3530_ALS1_IMP_SHIFT		(0)

#define LM3530_ALS2_IMP_SHIFT		(4)



/* Zone Boundary Register defaults */

#define LM3530_DEF_ZB_0			(0x33)

#define LM3530_DEF_ZB_1			(0x66)

#define LM3530_DEF_ZB_2			(0x99)

#define LM3530_DEF_ZB_3			(0xCC)



/* Zone Target Register defaults */

#define LM3530_DEF_ZT_0			(0x19)

#define LM3530_DEF_ZT_1			(0x33)

#define LM3530_DEF_ZT_2			(0x4C)

#define LM3530_DEF_ZT_3			(0x66)

#define LM3530_DEF_ZT_4			(0x7F)



struct lm3530_mode_map {

	const char *mode;

	enum lm3530_mode mode_val;

};



static struct lm3530_mode_map mode_map[] = {

	{ "man", LM3530_BL_MODE_MANUAL },

	{ "als", LM3530_BL_MODE_ALS },

	{ "pwm", LM3530_BL_MODE_PWM },

};



/**

 * struct lm3530_data

 * @led_dev: led class device

 * @client: i2c client

 * @pdata: LM3530 platform data

 * @mode: mode of operation - manual, ALS, PWM

 */

struct lm3530_data {

	struct led_classdev led_dev;

	struct i2c_client *client;

	struct lm3530_platform_data *pdata;

	enum lm3530_mode mode;

};



static const u8 lm3530_reg[LM3530_REG_MAX] = {

	LM3530_GEN_CONFIG,

	LM3530_ALS_CONFIG,

	LM3530_BRT_RAMP_RATE,

	LM3530_ALS_ZONE_REG,

	LM3530_ALS_IMP_SELECT,

	LM3530_BRT_CTRL_REG,

	LM3530_ALS_ZB0_REG,

	LM3530_ALS_ZB1_REG,

	LM3530_ALS_ZB2_REG,

	LM3530_ALS_ZB3_REG,

	LM3530_ALS_Z0T_REG,

	LM3530_ALS_Z1T_REG,

	LM3530_ALS_Z2T_REG,

	LM3530_ALS_Z3T_REG,

	LM3530_ALS_Z4T_REG,

};



static int lm3530_get_mode_from_str(const char *str)

{

	int i;



	for (i = 0; i < ARRAY_SIZE(mode_map); i++)

		if (sysfs_streq(str, mode_map[i].mode))

			return mode_map[i].mode_val;



	return -1;

}



static int lm3530_init_registers(struct lm3530_data *drvdata)

{

	int ret = 0;

	int i;

	u8 gen_config;

	u8 als_config = 0;

	u8 brt_ramp;

	u8 als_imp_sel = 0;

	u8 brightness;

	u8 reg_val[LM3530_REG_MAX];

	struct lm3530_platform_data *pltfm = drvdata->pdata;

	struct i2c_client *client = drvdata->client;



	gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |

			((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);



	if (drvdata->mode == LM3530_BL_MODE_MANUAL ||

	    drvdata->mode == LM3530_BL_MODE_ALS)

		gen_config |= (LM3530_ENABLE_I2C);



	if (drvdata->mode == LM3530_BL_MODE_ALS) {

		als_config =

			(pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |

			(LM3530_ENABLE_ALS) |

			(pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);



		als_imp_sel =

			(pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |

			(pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);

	}



	if (drvdata->mode == LM3530_BL_MODE_PWM)

		gen_config |= (LM3530_ENABLE_PWM) |

				(pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |

				(LM3530_ENABLE_PWM_SIMPLE);



	brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |

			(pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);



	brightness = pltfm->brt_val;



	reg_val[0] = gen_config;	/* LM3530_GEN_CONFIG */

	reg_val[1] = als_config;	/* LM3530_ALS_CONFIG */

	reg_val[2] = brt_ramp;		/* LM3530_BRT_RAMP_RATE */

	reg_val[3] = 0x00;		/* LM3530_ALS_ZONE_REG */

	reg_val[4] = als_imp_sel;	/* LM3530_ALS_IMP_SELECT */

	reg_val[5] = brightness;	/* LM3530_BRT_CTRL_REG */

	reg_val[6] = LM3530_DEF_ZB_0;	/* LM3530_ALS_ZB0_REG */

	reg_val[7] = LM3530_DEF_ZB_1;	/* LM3530_ALS_ZB1_REG */

	reg_val[8] = LM3530_DEF_ZB_2;	/* LM3530_ALS_ZB2_REG */

	reg_val[9] = LM3530_DEF_ZB_3;	/* LM3530_ALS_ZB3_REG */

	reg_val[10] = LM3530_DEF_ZT_0;	/* LM3530_ALS_Z0T_REG */

	reg_val[11] = LM3530_DEF_ZT_1;	/* LM3530_ALS_Z1T_REG */

	reg_val[12] = LM3530_DEF_ZT_2;	/* LM3530_ALS_Z2T_REG */

	reg_val[13] = LM3530_DEF_ZT_3;	/* LM3530_ALS_Z3T_REG */

	reg_val[14] = LM3530_DEF_ZT_4;	/* LM3530_ALS_Z4T_REG */



	for (i = 0; i < LM3530_REG_MAX; i++) {

		ret = i2c_smbus_write_byte_data(client,

				lm3530_reg[i], reg_val[i]);

		if (ret)

			break;

	}



	return ret;

}



static void lm3530_brightness_set(struct led_classdev *led_cdev,

				     enum led_brightness brt_val)

{

	int err;

	struct lm3530_data *drvdata =

	    container_of(led_cdev, struct lm3530_data, led_dev);



	switch (drvdata->mode) {

	case LM3530_BL_MODE_MANUAL:



		/* set the brightness in brightness control register*/

		err = i2c_smbus_write_byte_data(drvdata->client,

				LM3530_BRT_CTRL_REG, brt_val / 2);

		if (err)

			dev_err(&drvdata->client->dev,

				"Unable to set brightness: %d\n", err);

		break;

	case LM3530_BL_MODE_ALS:

		break;

	case LM3530_BL_MODE_PWM:

		break;

	default:

		break;

	}

}





static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute

				   *attr, const char *buf, size_t size)

{

	int err;

	struct i2c_client *client = container_of(

					dev->parent, struct i2c_client, dev);

	struct lm3530_data *drvdata = i2c_get_clientdata(client);

	int mode;



	mode = lm3530_get_mode_from_str(buf);

	if (mode < 0) {

		dev_err(dev, "Invalid mode\n");

		return -EINVAL;

	}



	if (mode == LM3530_BL_MODE_MANUAL)

		drvdata->mode = LM3530_BL_MODE_MANUAL;

	else if (mode == LM3530_BL_MODE_ALS)

		drvdata->mode = LM3530_BL_MODE_ALS;

	else if (mode == LM3530_BL_MODE_PWM) {

		dev_err(dev, "PWM mode not supported\n");

		return -EINVAL;

	}



	err = lm3530_init_registers(drvdata);

	if (err) {

		dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);

		return err;

	}



	return sizeof(drvdata->mode);

}



static DEVICE_ATTR(mode, 0644, NULL, lm3530_mode_set);



static int __devinit lm3530_probe(struct i2c_client *client,

			   const struct i2c_device_id *id)

{

	struct lm3530_platform_data *pdata = client->dev.platform_data;

	struct lm3530_data *drvdata;

	int err = 0;



	if (pdata == NULL) {

		dev_err(&client->dev, "platform data required\n");

		err = -ENODEV;

		goto err_out;

	}



	/* BL mode */

	if (pdata->mode > LM3530_BL_MODE_PWM) {

		dev_err(&client->dev, "Illegal Mode request\n");

		err = -EINVAL;

		goto err_out;

	}



	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {

		dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");

		err = -EIO;

		goto err_out;

	}



	drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);

	if (drvdata == NULL) {

		err = -ENOMEM;

		goto err_out;

	}



	drvdata->mode = pdata->mode;

	drvdata->client = client;

	drvdata->pdata = pdata;

	drvdata->led_dev.name = LM3530_LED_DEV;

	drvdata->led_dev.brightness_set = lm3530_brightness_set;



	i2c_set_clientdata(client, drvdata);



	err = lm3530_init_registers(drvdata);

	if (err < 0) {

		dev_err(&client->dev, "Register Init failed: %d\n", err);

		err = -ENODEV;

		goto err_reg_init;

	}



	err = led_classdev_register((struct device *)

				      &client->dev, &drvdata->led_dev);

	if (err < 0) {

		dev_err(&client->dev, "Register led class failed: %d\n", err);

		err = -ENODEV;

		goto err_class_register;

	}



	err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);

	if (err < 0) {

		dev_err(&client->dev, "File device creation failed: %d\n", err);

		err = -ENODEV;

		goto err_create_file;

	}



	return 0;



err_create_file:

	led_classdev_unregister(&drvdata->led_dev);

err_class_register:

err_reg_init:

	kfree(drvdata);

err_out:

	return err;

}



static int __devexit lm3530_remove(struct i2c_client *client)

{

	struct lm3530_data *drvdata = i2c_get_clientdata(client);



	device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);

	led_classdev_unregister(&drvdata->led_dev);

	kfree(drvdata);

	return 0;

}



static const struct i2c_device_id lm3530_id[] = {

	{LM3530_NAME, 0},

	{}

};



static struct i2c_driver lm3530_i2c_driver = {

	.probe = lm3530_probe,

	.remove = lm3530_remove,

	.id_table = lm3530_id,

	.driver = {

		.name = LM3530_NAME,

		.owner = THIS_MODULE,

	},

};



static int __init lm3530_init(void)

{

	return i2c_add_driver(&lm3530_i2c_driver);

}



static void __exit lm3530_exit(void)

{

	i2c_del_driver(&lm3530_i2c_driver);

}



module_init(lm3530_init);

module_exit(lm3530_exit);



MODULE_DESCRIPTION("Back Light driver for LM3530");

MODULE_LICENSE("GPL v2");

MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");

include/linux/led-lm3530.h

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/*

 * Copyright (C) 2011 ST-Ericsson SA.

 * Copyright (C) 2009 Motorola, Inc.

 *

 * License Terms: GNU General Public License v2

 *

 * Simple driver for National Semiconductor LM35330 Backlight driver chip

 *

 * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>

 * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>

 */



#ifndef _LINUX_LED_LM3530_H__

#define _LINUX_LED_LM3530_H__



#define LM3530_FS_CURR_5mA		(0) /* Full Scale Current */

#define LM3530_FS_CURR_8mA		(1)

#define LM3530_FS_CURR_12mA		(2)

#define LM3530_FS_CURR_15mA		(3)

#define LM3530_FS_CURR_19mA		(4)

#define LM3530_FS_CURR_22mA		(5)

#define LM3530_FS_CURR_26mA		(6)

#define LM3530_FS_CURR_29mA		(7)



#define LM3530_ALS_AVRG_TIME_32ms	(0) /* ALS Averaging Time */

#define LM3530_ALS_AVRG_TIME_64ms	(1)

#define LM3530_ALS_AVRG_TIME_128ms	(2)

#define LM3530_ALS_AVRG_TIME_256ms	(3)

#define LM3530_ALS_AVRG_TIME_512ms	(4)

#define LM3530_ALS_AVRG_TIME_1024ms	(5)

#define LM3530_ALS_AVRG_TIME_2048ms	(6)

#define LM3530_ALS_AVRG_TIME_4096ms	(7)



#define LM3530_RAMP_TIME_1ms		(0) /* Brigtness Ramp Time */

#define LM3530_RAMP_TIME_130ms		(1) /* Max to 0 and vice versa */

#define LM3530_RAMP_TIME_260ms		(2)

#define LM3530_RAMP_TIME_520ms		(3)

#define LM3530_RAMP_TIME_1s		(4)

#define LM3530_RAMP_TIME_2s		(5)

#define LM3530_RAMP_TIME_4s		(6)

#define LM3530_RAMP_TIME_8s		(7)



/* ALS Resistor Select */

#define LM3530_ALS_IMPD_Z		(0x00) /* ALS Impedence */

#define LM3530_ALS_IMPD_13_53kOhm	(0x01)

#define LM3530_ALS_IMPD_9_01kOhm	(0x02)

#define LM3530_ALS_IMPD_5_41kOhm	(0x03)

#define LM3530_ALS_IMPD_2_27kOhm	(0x04)

#define LM3530_ALS_IMPD_1_94kOhm	(0x05)

#define LM3530_ALS_IMPD_1_81kOhm	(0x06)

#define LM3530_ALS_IMPD_1_6kOhm		(0x07)

#define LM3530_ALS_IMPD_1_138kOhm	(0x08)

#define LM3530_ALS_IMPD_1_05kOhm	(0x09)

#define LM3530_ALS_IMPD_1_011kOhm	(0x0A)

#define LM3530_ALS_IMPD_941Ohm		(0x0B)

#define LM3530_ALS_IMPD_759Ohm		(0x0C)

#define LM3530_ALS_IMPD_719Ohm		(0x0D)

#define LM3530_ALS_IMPD_700Ohm		(0x0E)

#define LM3530_ALS_IMPD_667Ohm		(0x0F)



enum lm3530_mode {

	LM3530_BL_MODE_MANUAL = 0,	/* "man" */

	LM3530_BL_MODE_ALS,		/* "als" */

	LM3530_BL_MODE_PWM,		/* "pwm" */

};



/* ALS input select */

enum lm3530_als_mode {

	LM3530_INPUT_AVRG = 0,	/* ALS1 and ALS2 input average */

	LM3530_INPUT_ALS1,	/* ALS1 Input */

	LM3530_INPUT_ALS2,	/* ALS2 Input */

	LM3530_INPUT_CEIL,	/* Max of ALS1 and ALS2 */

};



/**

 * struct lm3530_platform_data

 * @mode: mode of operation i.e. Manual, ALS or PWM

 * @als_input_mode: select source of ALS input - ALS1/2 or average

 * @max_current: full scale LED current

 * @pwm_pol_hi: PWM input polarity - active high/active low

 * @als_avrg_time: ALS input averaging time

 * @brt_ramp_law: brightness mapping mode - exponential/linear

 * @brt_ramp_fall: rate of fall of led current

 * @brt_ramp_rise: rate of rise of led current

 * @als1_resistor_sel: internal resistance from ALS1 input to ground

 * @als2_resistor_sel: internal resistance from ALS2 input to ground

 * @brt_val: brightness value (0-255)

 */

struct lm3530_platform_data {

	enum lm3530_mode mode;

	enum lm3530_als_mode als_input_mode;



	u8 max_current;

	bool pwm_pol_hi;

	u8 als_avrg_time;



	bool brt_ramp_law;

	u8 brt_ramp_fall;

	u8 brt_ramp_rise;



	u8 als1_resistor_sel;

	u8 als2_resistor_sel;



	u8 brt_val;

};



#endif	/* _LINUX_LED_LM3530_H__ */

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