![Shreshtha Kumar Sahu](/assets/img/avatar_default.png)
Simple backlight driver for National Semiconductor LM3530. Presently only manual mode is supported, PWM and ALS support to be added. Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com> Cc: Linus Walleij <linus.walleij@stericsson.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
379 lines
9.5 KiB
C
379 lines
9.5 KiB
C
/*
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* Copyright (C) 2011 ST-Ericsson SA.
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* Copyright (C) 2009 Motorola, Inc.
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*
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* License Terms: GNU General Public License v2
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*
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* Simple driver for National Semiconductor LM3530 Backlight driver chip
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*
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* Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
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* based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
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*/
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#include <linux/i2c.h>
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#include <linux/leds.h>
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#include <linux/slab.h>
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#include <linux/platform_device.h>
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#include <linux/input.h>
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#include <linux/led-lm3530.h>
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#include <linux/types.h>
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#define LM3530_LED_DEV "lcd-backlight"
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#define LM3530_NAME "lm3530-led"
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#define LM3530_GEN_CONFIG 0x10
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#define LM3530_ALS_CONFIG 0x20
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#define LM3530_BRT_RAMP_RATE 0x30
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#define LM3530_ALS_ZONE_REG 0x40
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#define LM3530_ALS_IMP_SELECT 0x41
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#define LM3530_BRT_CTRL_REG 0xA0
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#define LM3530_ALS_ZB0_REG 0x60
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#define LM3530_ALS_ZB1_REG 0x61
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#define LM3530_ALS_ZB2_REG 0x62
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#define LM3530_ALS_ZB3_REG 0x63
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#define LM3530_ALS_Z0T_REG 0x70
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#define LM3530_ALS_Z1T_REG 0x71
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#define LM3530_ALS_Z2T_REG 0x72
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#define LM3530_ALS_Z3T_REG 0x73
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#define LM3530_ALS_Z4T_REG 0x74
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#define LM3530_REG_MAX 15
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/* General Control Register */
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#define LM3530_EN_I2C_SHIFT (0)
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#define LM3530_RAMP_LAW_SHIFT (1)
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#define LM3530_MAX_CURR_SHIFT (2)
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#define LM3530_EN_PWM_SHIFT (5)
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#define LM3530_PWM_POL_SHIFT (6)
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#define LM3530_EN_PWM_SIMPLE_SHIFT (7)
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#define LM3530_ENABLE_I2C (1 << LM3530_EN_I2C_SHIFT)
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#define LM3530_ENABLE_PWM (1 << LM3530_EN_PWM_SHIFT)
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#define LM3530_POL_LOW (1 << LM3530_PWM_POL_SHIFT)
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#define LM3530_ENABLE_PWM_SIMPLE (1 << LM3530_EN_PWM_SIMPLE_SHIFT)
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/* ALS Config Register Options */
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#define LM3530_ALS_AVG_TIME_SHIFT (0)
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#define LM3530_EN_ALS_SHIFT (3)
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#define LM3530_ALS_SEL_SHIFT (5)
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#define LM3530_ENABLE_ALS (3 << LM3530_EN_ALS_SHIFT)
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/* Brightness Ramp Rate Register */
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#define LM3530_BRT_RAMP_FALL_SHIFT (0)
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#define LM3530_BRT_RAMP_RISE_SHIFT (3)
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/* ALS Resistor Select */
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#define LM3530_ALS1_IMP_SHIFT (0)
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#define LM3530_ALS2_IMP_SHIFT (4)
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/* Zone Boundary Register defaults */
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#define LM3530_DEF_ZB_0 (0x33)
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#define LM3530_DEF_ZB_1 (0x66)
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#define LM3530_DEF_ZB_2 (0x99)
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#define LM3530_DEF_ZB_3 (0xCC)
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/* Zone Target Register defaults */
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#define LM3530_DEF_ZT_0 (0x19)
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#define LM3530_DEF_ZT_1 (0x33)
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#define LM3530_DEF_ZT_2 (0x4C)
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#define LM3530_DEF_ZT_3 (0x66)
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#define LM3530_DEF_ZT_4 (0x7F)
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struct lm3530_mode_map {
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const char *mode;
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enum lm3530_mode mode_val;
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};
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static struct lm3530_mode_map mode_map[] = {
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{ "man", LM3530_BL_MODE_MANUAL },
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{ "als", LM3530_BL_MODE_ALS },
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{ "pwm", LM3530_BL_MODE_PWM },
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};
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/**
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* struct lm3530_data
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* @led_dev: led class device
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* @client: i2c client
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* @pdata: LM3530 platform data
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* @mode: mode of operation - manual, ALS, PWM
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*/
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struct lm3530_data {
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struct led_classdev led_dev;
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struct i2c_client *client;
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struct lm3530_platform_data *pdata;
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enum lm3530_mode mode;
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};
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static const u8 lm3530_reg[LM3530_REG_MAX] = {
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LM3530_GEN_CONFIG,
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LM3530_ALS_CONFIG,
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LM3530_BRT_RAMP_RATE,
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LM3530_ALS_ZONE_REG,
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LM3530_ALS_IMP_SELECT,
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LM3530_BRT_CTRL_REG,
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LM3530_ALS_ZB0_REG,
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LM3530_ALS_ZB1_REG,
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LM3530_ALS_ZB2_REG,
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LM3530_ALS_ZB3_REG,
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LM3530_ALS_Z0T_REG,
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LM3530_ALS_Z1T_REG,
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LM3530_ALS_Z2T_REG,
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LM3530_ALS_Z3T_REG,
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LM3530_ALS_Z4T_REG,
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};
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static int lm3530_get_mode_from_str(const char *str)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(mode_map); i++)
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if (sysfs_streq(str, mode_map[i].mode))
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return mode_map[i].mode_val;
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return -1;
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}
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static int lm3530_init_registers(struct lm3530_data *drvdata)
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{
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int ret = 0;
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int i;
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u8 gen_config;
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u8 als_config = 0;
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u8 brt_ramp;
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u8 als_imp_sel = 0;
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u8 brightness;
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u8 reg_val[LM3530_REG_MAX];
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struct lm3530_platform_data *pltfm = drvdata->pdata;
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struct i2c_client *client = drvdata->client;
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gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
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((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
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if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
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drvdata->mode == LM3530_BL_MODE_ALS)
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gen_config |= (LM3530_ENABLE_I2C);
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if (drvdata->mode == LM3530_BL_MODE_ALS) {
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als_config =
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(pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
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(LM3530_ENABLE_ALS) |
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(pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
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als_imp_sel =
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(pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
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(pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
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}
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if (drvdata->mode == LM3530_BL_MODE_PWM)
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gen_config |= (LM3530_ENABLE_PWM) |
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(pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
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(LM3530_ENABLE_PWM_SIMPLE);
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brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
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(pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
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brightness = pltfm->brt_val;
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reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */
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reg_val[1] = als_config; /* LM3530_ALS_CONFIG */
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reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */
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reg_val[3] = 0x00; /* LM3530_ALS_ZONE_REG */
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reg_val[4] = als_imp_sel; /* LM3530_ALS_IMP_SELECT */
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reg_val[5] = brightness; /* LM3530_BRT_CTRL_REG */
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reg_val[6] = LM3530_DEF_ZB_0; /* LM3530_ALS_ZB0_REG */
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reg_val[7] = LM3530_DEF_ZB_1; /* LM3530_ALS_ZB1_REG */
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reg_val[8] = LM3530_DEF_ZB_2; /* LM3530_ALS_ZB2_REG */
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reg_val[9] = LM3530_DEF_ZB_3; /* LM3530_ALS_ZB3_REG */
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reg_val[10] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */
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reg_val[11] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */
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reg_val[12] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */
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reg_val[13] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */
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reg_val[14] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */
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for (i = 0; i < LM3530_REG_MAX; i++) {
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ret = i2c_smbus_write_byte_data(client,
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lm3530_reg[i], reg_val[i]);
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if (ret)
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break;
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}
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return ret;
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}
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static void lm3530_brightness_set(struct led_classdev *led_cdev,
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enum led_brightness brt_val)
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{
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int err;
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struct lm3530_data *drvdata =
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container_of(led_cdev, struct lm3530_data, led_dev);
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switch (drvdata->mode) {
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case LM3530_BL_MODE_MANUAL:
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/* set the brightness in brightness control register*/
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err = i2c_smbus_write_byte_data(drvdata->client,
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LM3530_BRT_CTRL_REG, brt_val / 2);
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if (err)
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dev_err(&drvdata->client->dev,
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"Unable to set brightness: %d\n", err);
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break;
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case LM3530_BL_MODE_ALS:
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break;
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case LM3530_BL_MODE_PWM:
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break;
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default:
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break;
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}
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}
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static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
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*attr, const char *buf, size_t size)
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{
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int err;
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struct i2c_client *client = container_of(
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dev->parent, struct i2c_client, dev);
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struct lm3530_data *drvdata = i2c_get_clientdata(client);
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int mode;
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mode = lm3530_get_mode_from_str(buf);
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if (mode < 0) {
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dev_err(dev, "Invalid mode\n");
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return -EINVAL;
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}
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if (mode == LM3530_BL_MODE_MANUAL)
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drvdata->mode = LM3530_BL_MODE_MANUAL;
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else if (mode == LM3530_BL_MODE_ALS)
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drvdata->mode = LM3530_BL_MODE_ALS;
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else if (mode == LM3530_BL_MODE_PWM) {
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dev_err(dev, "PWM mode not supported\n");
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return -EINVAL;
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}
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err = lm3530_init_registers(drvdata);
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if (err) {
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dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
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return err;
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}
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return sizeof(drvdata->mode);
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}
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static DEVICE_ATTR(mode, 0644, NULL, lm3530_mode_set);
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static int __devinit lm3530_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct lm3530_platform_data *pdata = client->dev.platform_data;
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struct lm3530_data *drvdata;
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int err = 0;
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if (pdata == NULL) {
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dev_err(&client->dev, "platform data required\n");
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err = -ENODEV;
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goto err_out;
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}
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/* BL mode */
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if (pdata->mode > LM3530_BL_MODE_PWM) {
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dev_err(&client->dev, "Illegal Mode request\n");
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err = -EINVAL;
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goto err_out;
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}
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
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dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
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err = -EIO;
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goto err_out;
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}
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drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
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if (drvdata == NULL) {
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err = -ENOMEM;
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goto err_out;
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}
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drvdata->mode = pdata->mode;
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drvdata->client = client;
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drvdata->pdata = pdata;
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drvdata->led_dev.name = LM3530_LED_DEV;
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drvdata->led_dev.brightness_set = lm3530_brightness_set;
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i2c_set_clientdata(client, drvdata);
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err = lm3530_init_registers(drvdata);
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if (err < 0) {
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dev_err(&client->dev, "Register Init failed: %d\n", err);
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err = -ENODEV;
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goto err_reg_init;
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}
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err = led_classdev_register((struct device *)
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&client->dev, &drvdata->led_dev);
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if (err < 0) {
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dev_err(&client->dev, "Register led class failed: %d\n", err);
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err = -ENODEV;
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goto err_class_register;
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}
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err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
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if (err < 0) {
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dev_err(&client->dev, "File device creation failed: %d\n", err);
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err = -ENODEV;
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goto err_create_file;
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}
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return 0;
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err_create_file:
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led_classdev_unregister(&drvdata->led_dev);
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err_class_register:
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err_reg_init:
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kfree(drvdata);
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err_out:
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return err;
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}
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static int __devexit lm3530_remove(struct i2c_client *client)
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{
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struct lm3530_data *drvdata = i2c_get_clientdata(client);
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device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
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led_classdev_unregister(&drvdata->led_dev);
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kfree(drvdata);
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return 0;
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}
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static const struct i2c_device_id lm3530_id[] = {
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{LM3530_NAME, 0},
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{}
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};
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static struct i2c_driver lm3530_i2c_driver = {
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.probe = lm3530_probe,
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.remove = lm3530_remove,
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.id_table = lm3530_id,
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.driver = {
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.name = LM3530_NAME,
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.owner = THIS_MODULE,
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},
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};
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static int __init lm3530_init(void)
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{
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return i2c_add_driver(&lm3530_i2c_driver);
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}
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static void __exit lm3530_exit(void)
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{
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i2c_del_driver(&lm3530_i2c_driver);
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}
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module_init(lm3530_init);
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module_exit(lm3530_exit);
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MODULE_DESCRIPTION("Back Light driver for LM3530");
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");
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