488 lines
13 KiB
C
488 lines
13 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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#include <linux/regulator/consumer.h>
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#include <linux/module.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_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 14
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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_ALS_ZB_MAX (4)
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#define LM3530_ALS_WINDOW_mV (1000)
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#define LM3530_ALS_OFFSET_mV (4)
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/* Zone Target Register defaults */
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#define LM3530_DEF_ZT_0 (0x7F)
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#define LM3530_DEF_ZT_1 (0x66)
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#define LM3530_DEF_ZT_2 (0x4C)
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#define LM3530_DEF_ZT_3 (0x33)
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#define LM3530_DEF_ZT_4 (0x19)
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/* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */
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#define MAX_BRIGHTNESS (127)
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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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* @regulator: regulator
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* @brighness: previous brightness value
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* @enable: regulator is enabled
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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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struct regulator *regulator;
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enum led_brightness brightness;
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bool enable;
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};
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/*
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* struct lm3530_als_data
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* @config : value of ALS configuration register
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* @imp_sel : value of ALS resistor select register
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* @zone : values of ALS ZB(Zone Boundary) registers
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*/
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struct lm3530_als_data {
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u8 config;
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u8 imp_sel;
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u8 zones[LM3530_ALS_ZB_MAX];
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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_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 -EINVAL;
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}
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static void lm3530_als_configure(struct lm3530_platform_data *pdata,
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struct lm3530_als_data *als)
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{
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int i;
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u32 als_vmin, als_vmax, als_vstep;
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if (pdata->als_vmax == 0) {
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pdata->als_vmin = 0;
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pdata->als_vmax = LM3530_ALS_WINDOW_mV;
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}
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als_vmin = pdata->als_vmin;
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als_vmax = pdata->als_vmax;
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if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
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pdata->als_vmax = als_vmax = als_vmin + LM3530_ALS_WINDOW_mV;
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/* n zone boundary makes n+1 zones */
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als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
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for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
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als->zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
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als_vstep + (i * als_vstep)) * LED_FULL) / 1000;
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als->config =
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(pdata->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
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(LM3530_ENABLE_ALS) |
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(pdata->als_input_mode << LM3530_ALS_SEL_SHIFT);
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als->imp_sel =
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(pdata->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
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(pdata->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
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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 brt_ramp;
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u8 brightness;
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u8 reg_val[LM3530_REG_MAX];
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struct lm3530_platform_data *pdata = drvdata->pdata;
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struct i2c_client *client = drvdata->client;
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struct lm3530_pwm_data *pwm = &pdata->pwm_data;
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struct lm3530_als_data als;
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memset(&als, 0, sizeof(struct lm3530_als_data));
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gen_config = (pdata->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
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((pdata->max_current & 7) << LM3530_MAX_CURR_SHIFT);
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switch (drvdata->mode) {
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case LM3530_BL_MODE_MANUAL:
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gen_config |= LM3530_ENABLE_I2C;
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break;
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case LM3530_BL_MODE_ALS:
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gen_config |= LM3530_ENABLE_I2C;
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lm3530_als_configure(pdata, &als);
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break;
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case LM3530_BL_MODE_PWM:
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gen_config |= LM3530_ENABLE_PWM | LM3530_ENABLE_PWM_SIMPLE |
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(pdata->pwm_pol_hi << LM3530_PWM_POL_SHIFT);
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break;
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}
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brt_ramp = (pdata->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
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(pdata->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
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if (drvdata->brightness)
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brightness = drvdata->brightness;
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else
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brightness = drvdata->brightness = pdata->brt_val;
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if (brightness > drvdata->led_dev.max_brightness)
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brightness = drvdata->led_dev.max_brightness;
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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] = als.imp_sel; /* LM3530_ALS_IMP_SELECT */
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reg_val[4] = brightness; /* LM3530_BRT_CTRL_REG */
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reg_val[5] = als.zones[0]; /* LM3530_ALS_ZB0_REG */
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reg_val[6] = als.zones[1]; /* LM3530_ALS_ZB1_REG */
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reg_val[7] = als.zones[2]; /* LM3530_ALS_ZB2_REG */
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reg_val[8] = als.zones[3]; /* LM3530_ALS_ZB3_REG */
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reg_val[9] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */
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reg_val[10] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */
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reg_val[11] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */
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reg_val[12] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */
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reg_val[13] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */
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if (!drvdata->enable) {
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ret = regulator_enable(drvdata->regulator);
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if (ret) {
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dev_err(&drvdata->client->dev,
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"Enable regulator failed\n");
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return ret;
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}
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drvdata->enable = true;
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}
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for (i = 0; i < LM3530_REG_MAX; i++) {
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/* do not update brightness register when pwm mode */
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if (lm3530_reg[i] == LM3530_BRT_CTRL_REG &&
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drvdata->mode == LM3530_BL_MODE_PWM) {
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if (pwm->pwm_set_intensity)
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pwm->pwm_set_intensity(reg_val[i],
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drvdata->led_dev.max_brightness);
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continue;
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}
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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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struct lm3530_platform_data *pdata = drvdata->pdata;
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struct lm3530_pwm_data *pwm = &pdata->pwm_data;
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u8 max_brightness = led_cdev->max_brightness;
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switch (drvdata->mode) {
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case LM3530_BL_MODE_MANUAL:
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if (!drvdata->enable) {
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err = lm3530_init_registers(drvdata);
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if (err) {
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dev_err(&drvdata->client->dev,
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"Register Init failed: %d\n", err);
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break;
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}
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}
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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);
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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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else
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drvdata->brightness = brt_val;
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if (brt_val == 0) {
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err = regulator_disable(drvdata->regulator);
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if (err)
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dev_err(&drvdata->client->dev,
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"Disable regulator failed\n");
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drvdata->enable = false;
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}
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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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if (pwm->pwm_set_intensity)
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pwm->pwm_set_intensity(brt_val, max_brightness);
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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_get(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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struct lm3530_data *drvdata;
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int i, len = 0;
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drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
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for (i = 0; i < ARRAY_SIZE(mode_map); i++)
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if (drvdata->mode == mode_map[i].mode_val)
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len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
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else
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len += sprintf(buf + len, "%s ", mode_map[i].mode);
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len += sprintf(buf + len, "\n");
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return len;
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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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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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struct lm3530_data *drvdata;
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struct lm3530_pwm_data *pwm;
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u8 max_brightness;
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int mode, err;
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drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
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pwm = &drvdata->pdata->pwm_data;
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max_brightness = led_cdev->max_brightness;
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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 mode;
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}
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drvdata->mode = mode;
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/* set pwm to low if unnecessary */
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if (mode != LM3530_BL_MODE_PWM && pwm->pwm_set_intensity)
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pwm->pwm_set_intensity(0, max_brightness);
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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, lm3530_mode_get, lm3530_mode_set);
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static int 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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return -ENODEV;
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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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return -EINVAL;
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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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return -EIO;
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}
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drvdata = devm_kzalloc(&client->dev, sizeof(struct lm3530_data),
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GFP_KERNEL);
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if (drvdata == NULL)
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return -ENOMEM;
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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->brightness = LED_OFF;
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drvdata->enable = false;
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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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drvdata->led_dev.max_brightness = MAX_BRIGHTNESS;
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i2c_set_clientdata(client, drvdata);
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drvdata->regulator = devm_regulator_get(&client->dev, "vin");
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if (IS_ERR(drvdata->regulator)) {
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dev_err(&client->dev, "regulator get failed\n");
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err = PTR_ERR(drvdata->regulator);
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drvdata->regulator = NULL;
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return err;
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}
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if (drvdata->pdata->brt_val) {
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err = lm3530_init_registers(drvdata);
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if (err < 0) {
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dev_err(&client->dev,
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"Register Init failed: %d\n", err);
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return err;
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}
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}
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err = led_classdev_register(&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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return err;
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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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return err;
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}
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static int 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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|
|
if (drvdata->enable)
|
|
regulator_disable(drvdata->regulator);
|
|
led_classdev_unregister(&drvdata->led_dev);
|
|
return 0;
|
|
}
|
|
|
|
static const struct i2c_device_id lm3530_id[] = {
|
|
{LM3530_NAME, 0},
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, lm3530_id);
|
|
|
|
static struct i2c_driver lm3530_i2c_driver = {
|
|
.probe = lm3530_probe,
|
|
.remove = lm3530_remove,
|
|
.id_table = lm3530_id,
|
|
.driver = {
|
|
.name = LM3530_NAME,
|
|
.owner = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
module_i2c_driver(lm3530_i2c_driver);
|
|
|
|
MODULE_DESCRIPTION("Back Light driver for LM3530");
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");
|