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![Bhushan Shah](/assets/img/avatar_default.png)
In the lm3630a_chip_init we try to write to 0x50 register, which is higher value then the max_register value, this resulted in regmap_write return -EIO. Fix this by bumping REG_MAX value to 0x50. This code was introduced with the chip revision in commit28e64a68a2
, however setting filter strength was failing silently because it used unsigned int for storing and comparing the return values. Bug related to signedness was fixed in2a0c316bf3
, which made it error out correctly instead of failing silently. I found this issue by using this driver on LGE Nexus 5 (hammerhead). After this commit lm3630a_chip_init succeeds instead of failing with -EIO. Fixes:28e64a68a2
("backlight: lm3630: apply chip revision") Fixes:2a0c316bf3
("drivers/video/backlight/lm3630a_bl.c: fix signedness bug in lm3630a_chip_init()") Suggested-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Bhushan Shah <bshah@kde.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
489 lines
13 KiB
C
489 lines
13 KiB
C
/*
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* Simple driver for Texas Instruments LM3630A Backlight driver chip
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* Copyright (C) 2012 Texas Instruments
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/i2c.h>
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#include <linux/backlight.h>
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#include <linux/err.h>
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#include <linux/delay.h>
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#include <linux/uaccess.h>
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#include <linux/interrupt.h>
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#include <linux/regmap.h>
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#include <linux/pwm.h>
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#include <linux/platform_data/lm3630a_bl.h>
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#define REG_CTRL 0x00
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#define REG_BOOST 0x02
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#define REG_CONFIG 0x01
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#define REG_BRT_A 0x03
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#define REG_BRT_B 0x04
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#define REG_I_A 0x05
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#define REG_I_B 0x06
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#define REG_INT_STATUS 0x09
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#define REG_INT_EN 0x0A
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#define REG_FAULT 0x0B
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#define REG_PWM_OUTLOW 0x12
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#define REG_PWM_OUTHIGH 0x13
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#define REG_FILTER_STRENGTH 0x50
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#define REG_MAX 0x50
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#define INT_DEBOUNCE_MSEC 10
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struct lm3630a_chip {
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struct device *dev;
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struct delayed_work work;
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int irq;
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struct workqueue_struct *irqthread;
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struct lm3630a_platform_data *pdata;
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struct backlight_device *bleda;
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struct backlight_device *bledb;
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struct regmap *regmap;
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struct pwm_device *pwmd;
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};
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/* i2c access */
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static int lm3630a_read(struct lm3630a_chip *pchip, unsigned int reg)
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{
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int rval;
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unsigned int reg_val;
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rval = regmap_read(pchip->regmap, reg, ®_val);
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if (rval < 0)
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return rval;
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return reg_val & 0xFF;
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}
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static int lm3630a_write(struct lm3630a_chip *pchip,
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unsigned int reg, unsigned int data)
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{
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return regmap_write(pchip->regmap, reg, data);
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}
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static int lm3630a_update(struct lm3630a_chip *pchip,
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unsigned int reg, unsigned int mask,
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unsigned int data)
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{
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return regmap_update_bits(pchip->regmap, reg, mask, data);
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}
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/* initialize chip */
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static int lm3630a_chip_init(struct lm3630a_chip *pchip)
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{
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int rval;
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struct lm3630a_platform_data *pdata = pchip->pdata;
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usleep_range(1000, 2000);
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/* set Filter Strength Register */
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rval = lm3630a_write(pchip, REG_FILTER_STRENGTH, 0x03);
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/* set Cofig. register */
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rval |= lm3630a_update(pchip, REG_CONFIG, 0x07, pdata->pwm_ctrl);
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/* set boost control */
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rval |= lm3630a_write(pchip, REG_BOOST, 0x38);
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/* set current A */
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rval |= lm3630a_update(pchip, REG_I_A, 0x1F, 0x1F);
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/* set current B */
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rval |= lm3630a_write(pchip, REG_I_B, 0x1F);
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/* set control */
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rval |= lm3630a_update(pchip, REG_CTRL, 0x14, pdata->leda_ctrl);
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rval |= lm3630a_update(pchip, REG_CTRL, 0x0B, pdata->ledb_ctrl);
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usleep_range(1000, 2000);
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/* set brightness A and B */
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rval |= lm3630a_write(pchip, REG_BRT_A, pdata->leda_init_brt);
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rval |= lm3630a_write(pchip, REG_BRT_B, pdata->ledb_init_brt);
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if (rval < 0)
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dev_err(pchip->dev, "i2c failed to access register\n");
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return rval;
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}
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/* interrupt handling */
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static void lm3630a_delayed_func(struct work_struct *work)
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{
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int rval;
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struct lm3630a_chip *pchip;
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pchip = container_of(work, struct lm3630a_chip, work.work);
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rval = lm3630a_read(pchip, REG_INT_STATUS);
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if (rval < 0) {
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dev_err(pchip->dev,
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"i2c failed to access REG_INT_STATUS Register\n");
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return;
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}
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dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", rval);
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}
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static irqreturn_t lm3630a_isr_func(int irq, void *chip)
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{
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int rval;
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struct lm3630a_chip *pchip = chip;
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unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC);
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queue_delayed_work(pchip->irqthread, &pchip->work, delay);
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rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
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if (rval < 0) {
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dev_err(pchip->dev, "i2c failed to access register\n");
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return IRQ_NONE;
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}
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return IRQ_HANDLED;
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}
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static int lm3630a_intr_config(struct lm3630a_chip *pchip)
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{
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int rval;
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rval = lm3630a_write(pchip, REG_INT_EN, 0x87);
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if (rval < 0)
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return rval;
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INIT_DELAYED_WORK(&pchip->work, lm3630a_delayed_func);
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pchip->irqthread = create_singlethread_workqueue("lm3630a-irqthd");
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if (!pchip->irqthread) {
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dev_err(pchip->dev, "create irq thread fail\n");
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return -ENOMEM;
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}
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if (request_threaded_irq
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(pchip->irq, NULL, lm3630a_isr_func,
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IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630a_irq", pchip)) {
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dev_err(pchip->dev, "request threaded irq fail\n");
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destroy_workqueue(pchip->irqthread);
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return -ENOMEM;
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}
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return rval;
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}
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static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
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{
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unsigned int period = pchip->pdata->pwm_period;
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unsigned int duty = br * period / br_max;
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pwm_config(pchip->pwmd, duty, period);
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if (duty)
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pwm_enable(pchip->pwmd);
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else
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pwm_disable(pchip->pwmd);
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}
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/* update and get brightness */
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static int lm3630a_bank_a_update_status(struct backlight_device *bl)
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{
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int ret;
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struct lm3630a_chip *pchip = bl_get_data(bl);
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enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
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/* pwm control */
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if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
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lm3630a_pwm_ctrl(pchip, bl->props.brightness,
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bl->props.max_brightness);
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return bl->props.brightness;
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}
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/* disable sleep */
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ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
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if (ret < 0)
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goto out_i2c_err;
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usleep_range(1000, 2000);
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/* minimum brightness is 0x04 */
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ret = lm3630a_write(pchip, REG_BRT_A, bl->props.brightness);
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if (bl->props.brightness < 0x4)
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ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0);
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else
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ret |= lm3630a_update(pchip, REG_CTRL,
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LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
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if (ret < 0)
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goto out_i2c_err;
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return bl->props.brightness;
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out_i2c_err:
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dev_err(pchip->dev, "i2c failed to access\n");
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return bl->props.brightness;
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}
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static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
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{
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int brightness, rval;
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struct lm3630a_chip *pchip = bl_get_data(bl);
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enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
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if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
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rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
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if (rval < 0)
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goto out_i2c_err;
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brightness = (rval & 0x01) << 8;
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rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
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if (rval < 0)
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goto out_i2c_err;
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brightness |= rval;
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goto out;
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}
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/* disable sleep */
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rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
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if (rval < 0)
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goto out_i2c_err;
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usleep_range(1000, 2000);
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rval = lm3630a_read(pchip, REG_BRT_A);
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if (rval < 0)
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goto out_i2c_err;
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brightness = rval;
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out:
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bl->props.brightness = brightness;
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return bl->props.brightness;
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out_i2c_err:
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dev_err(pchip->dev, "i2c failed to access register\n");
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return 0;
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}
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static const struct backlight_ops lm3630a_bank_a_ops = {
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.options = BL_CORE_SUSPENDRESUME,
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.update_status = lm3630a_bank_a_update_status,
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.get_brightness = lm3630a_bank_a_get_brightness,
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};
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/* update and get brightness */
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static int lm3630a_bank_b_update_status(struct backlight_device *bl)
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{
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int ret;
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struct lm3630a_chip *pchip = bl_get_data(bl);
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enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
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/* pwm control */
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if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
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lm3630a_pwm_ctrl(pchip, bl->props.brightness,
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bl->props.max_brightness);
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return bl->props.brightness;
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}
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/* disable sleep */
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ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
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if (ret < 0)
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goto out_i2c_err;
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usleep_range(1000, 2000);
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/* minimum brightness is 0x04 */
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ret = lm3630a_write(pchip, REG_BRT_B, bl->props.brightness);
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if (bl->props.brightness < 0x4)
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ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0);
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else
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ret |= lm3630a_update(pchip, REG_CTRL,
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LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
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if (ret < 0)
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goto out_i2c_err;
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return bl->props.brightness;
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out_i2c_err:
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dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");
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return bl->props.brightness;
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}
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static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
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{
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int brightness, rval;
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struct lm3630a_chip *pchip = bl_get_data(bl);
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enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
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if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
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rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
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if (rval < 0)
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goto out_i2c_err;
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brightness = (rval & 0x01) << 8;
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rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
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if (rval < 0)
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goto out_i2c_err;
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brightness |= rval;
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goto out;
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}
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/* disable sleep */
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rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
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if (rval < 0)
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goto out_i2c_err;
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usleep_range(1000, 2000);
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rval = lm3630a_read(pchip, REG_BRT_B);
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if (rval < 0)
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goto out_i2c_err;
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brightness = rval;
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out:
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bl->props.brightness = brightness;
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return bl->props.brightness;
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out_i2c_err:
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dev_err(pchip->dev, "i2c failed to access register\n");
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return 0;
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}
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static const struct backlight_ops lm3630a_bank_b_ops = {
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.options = BL_CORE_SUSPENDRESUME,
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.update_status = lm3630a_bank_b_update_status,
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.get_brightness = lm3630a_bank_b_get_brightness,
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};
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static int lm3630a_backlight_register(struct lm3630a_chip *pchip)
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{
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struct backlight_properties props;
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struct lm3630a_platform_data *pdata = pchip->pdata;
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props.type = BACKLIGHT_RAW;
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if (pdata->leda_ctrl != LM3630A_LEDA_DISABLE) {
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props.brightness = pdata->leda_init_brt;
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props.max_brightness = pdata->leda_max_brt;
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pchip->bleda =
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devm_backlight_device_register(pchip->dev, "lm3630a_leda",
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pchip->dev, pchip,
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&lm3630a_bank_a_ops, &props);
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if (IS_ERR(pchip->bleda))
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return PTR_ERR(pchip->bleda);
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}
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if ((pdata->ledb_ctrl != LM3630A_LEDB_DISABLE) &&
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(pdata->ledb_ctrl != LM3630A_LEDB_ON_A)) {
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props.brightness = pdata->ledb_init_brt;
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props.max_brightness = pdata->ledb_max_brt;
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pchip->bledb =
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devm_backlight_device_register(pchip->dev, "lm3630a_ledb",
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pchip->dev, pchip,
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&lm3630a_bank_b_ops, &props);
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if (IS_ERR(pchip->bledb))
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return PTR_ERR(pchip->bledb);
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}
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return 0;
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}
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static const struct regmap_config lm3630a_regmap = {
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.reg_bits = 8,
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.val_bits = 8,
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.max_register = REG_MAX,
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};
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static int lm3630a_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev);
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struct lm3630a_chip *pchip;
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int rval;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
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dev_err(&client->dev, "fail : i2c functionality check\n");
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return -EOPNOTSUPP;
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}
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pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip),
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GFP_KERNEL);
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if (!pchip)
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return -ENOMEM;
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pchip->dev = &client->dev;
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pchip->regmap = devm_regmap_init_i2c(client, &lm3630a_regmap);
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if (IS_ERR(pchip->regmap)) {
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rval = PTR_ERR(pchip->regmap);
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dev_err(&client->dev, "fail : allocate reg. map: %d\n", rval);
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return rval;
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}
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i2c_set_clientdata(client, pchip);
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if (pdata == NULL) {
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pdata = devm_kzalloc(pchip->dev,
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sizeof(struct lm3630a_platform_data),
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GFP_KERNEL);
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if (pdata == NULL)
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return -ENOMEM;
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/* default values */
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pdata->leda_ctrl = LM3630A_LEDA_ENABLE;
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pdata->ledb_ctrl = LM3630A_LEDB_ENABLE;
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pdata->leda_max_brt = LM3630A_MAX_BRIGHTNESS;
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pdata->ledb_max_brt = LM3630A_MAX_BRIGHTNESS;
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pdata->leda_init_brt = LM3630A_MAX_BRIGHTNESS;
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pdata->ledb_init_brt = LM3630A_MAX_BRIGHTNESS;
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}
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pchip->pdata = pdata;
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/* chip initialize */
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rval = lm3630a_chip_init(pchip);
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if (rval < 0) {
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dev_err(&client->dev, "fail : init chip\n");
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return rval;
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}
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/* backlight register */
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rval = lm3630a_backlight_register(pchip);
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if (rval < 0) {
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dev_err(&client->dev, "fail : backlight register.\n");
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return rval;
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}
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/* pwm */
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if (pdata->pwm_ctrl != LM3630A_PWM_DISABLE) {
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pchip->pwmd = devm_pwm_get(pchip->dev, "lm3630a-pwm");
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if (IS_ERR(pchip->pwmd)) {
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dev_err(&client->dev, "fail : get pwm device\n");
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return PTR_ERR(pchip->pwmd);
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}
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/*
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* FIXME: pwm_apply_args() should be removed when switching to
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* the atomic PWM API.
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*/
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pwm_apply_args(pchip->pwmd);
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}
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/* interrupt enable : irq 0 is not allowed */
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pchip->irq = client->irq;
|
|
if (pchip->irq) {
|
|
rval = lm3630a_intr_config(pchip);
|
|
if (rval < 0)
|
|
return rval;
|
|
}
|
|
dev_info(&client->dev, "LM3630A backlight register OK.\n");
|
|
return 0;
|
|
}
|
|
|
|
static int lm3630a_remove(struct i2c_client *client)
|
|
{
|
|
int rval;
|
|
struct lm3630a_chip *pchip = i2c_get_clientdata(client);
|
|
|
|
rval = lm3630a_write(pchip, REG_BRT_A, 0);
|
|
if (rval < 0)
|
|
dev_err(pchip->dev, "i2c failed to access register\n");
|
|
|
|
rval = lm3630a_write(pchip, REG_BRT_B, 0);
|
|
if (rval < 0)
|
|
dev_err(pchip->dev, "i2c failed to access register\n");
|
|
|
|
if (pchip->irq) {
|
|
free_irq(pchip->irq, pchip);
|
|
flush_workqueue(pchip->irqthread);
|
|
destroy_workqueue(pchip->irqthread);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static const struct i2c_device_id lm3630a_id[] = {
|
|
{LM3630A_NAME, 0},
|
|
{}
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(i2c, lm3630a_id);
|
|
|
|
static struct i2c_driver lm3630a_i2c_driver = {
|
|
.driver = {
|
|
.name = LM3630A_NAME,
|
|
},
|
|
.probe = lm3630a_probe,
|
|
.remove = lm3630a_remove,
|
|
.id_table = lm3630a_id,
|
|
};
|
|
|
|
module_i2c_driver(lm3630a_i2c_driver);
|
|
|
|
MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
|
|
MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
|
|
MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>");
|
|
MODULE_LICENSE("GPL v2");
|