304 lines
5.7 KiB
C
304 lines
5.7 KiB
C
/*
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* LED driver for WM8350 driven LEDS.
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*
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* Copyright(C) 2007, 2008 Wolfson Microelectronics PLC.
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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/kernel.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/leds.h>
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#include <linux/err.h>
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#include <linux/mfd/wm8350/pmic.h>
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#include <linux/regulator/consumer.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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/* Microamps */
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static const int isink_cur[] = {
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4,
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5,
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6,
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7,
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8,
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10,
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11,
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14,
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16,
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19,
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23,
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27,
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32,
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39,
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46,
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54,
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65,
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77,
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92,
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109,
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130,
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154,
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183,
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218,
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259,
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308,
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367,
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436,
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518,
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616,
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733,
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872,
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1037,
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1233,
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1466,
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1744,
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2073,
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2466,
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2933,
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3487,
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4147,
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4932,
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5865,
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6975,
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8294,
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9864,
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11730,
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13949,
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16589,
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19728,
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23460,
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27899,
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33178,
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39455,
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46920,
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55798,
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66355,
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78910,
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93840,
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111596,
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132710,
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157820,
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187681,
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223191
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};
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#define to_wm8350_led(led_cdev) \
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container_of(led_cdev, struct wm8350_led, cdev)
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static void wm8350_led_enable(struct wm8350_led *led)
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{
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int ret;
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if (led->enabled)
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return;
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ret = regulator_enable(led->isink);
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if (ret != 0) {
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dev_err(led->cdev.dev, "Failed to enable ISINK: %d\n", ret);
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return;
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}
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ret = regulator_enable(led->dcdc);
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if (ret != 0) {
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dev_err(led->cdev.dev, "Failed to enable DCDC: %d\n", ret);
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regulator_disable(led->isink);
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return;
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}
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led->enabled = 1;
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}
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static void wm8350_led_disable(struct wm8350_led *led)
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{
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int ret;
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if (!led->enabled)
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return;
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ret = regulator_disable(led->dcdc);
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if (ret != 0) {
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dev_err(led->cdev.dev, "Failed to disable DCDC: %d\n", ret);
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return;
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}
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ret = regulator_disable(led->isink);
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if (ret != 0) {
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dev_err(led->cdev.dev, "Failed to disable ISINK: %d\n", ret);
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regulator_enable(led->dcdc);
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return;
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}
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led->enabled = 0;
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}
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static void led_work(struct work_struct *work)
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{
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struct wm8350_led *led = container_of(work, struct wm8350_led, work);
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int ret;
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int uA;
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unsigned long flags;
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mutex_lock(&led->mutex);
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spin_lock_irqsave(&led->value_lock, flags);
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if (led->value == LED_OFF) {
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spin_unlock_irqrestore(&led->value_lock, flags);
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wm8350_led_disable(led);
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goto out;
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}
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/* This scales linearly into the index of valid current
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* settings which results in a linear scaling of perceived
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* brightness due to the non-linear current settings provided
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* by the hardware.
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*/
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uA = (led->max_uA_index * led->value) / LED_FULL;
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spin_unlock_irqrestore(&led->value_lock, flags);
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BUG_ON(uA >= ARRAY_SIZE(isink_cur));
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ret = regulator_set_current_limit(led->isink, isink_cur[uA],
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isink_cur[uA]);
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if (ret != 0)
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dev_err(led->cdev.dev, "Failed to set %duA: %d\n",
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isink_cur[uA], ret);
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wm8350_led_enable(led);
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out:
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mutex_unlock(&led->mutex);
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}
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static void wm8350_led_set(struct led_classdev *led_cdev,
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enum led_brightness value)
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{
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struct wm8350_led *led = to_wm8350_led(led_cdev);
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unsigned long flags;
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spin_lock_irqsave(&led->value_lock, flags);
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led->value = value;
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schedule_work(&led->work);
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spin_unlock_irqrestore(&led->value_lock, flags);
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}
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static void wm8350_led_shutdown(struct platform_device *pdev)
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{
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struct wm8350_led *led = platform_get_drvdata(pdev);
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mutex_lock(&led->mutex);
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led->value = LED_OFF;
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wm8350_led_disable(led);
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mutex_unlock(&led->mutex);
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}
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static int wm8350_led_probe(struct platform_device *pdev)
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{
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struct regulator *isink, *dcdc;
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struct wm8350_led *led;
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struct wm8350_led_platform_data *pdata = pdev->dev.platform_data;
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int ret, i;
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if (pdata == NULL) {
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dev_err(&pdev->dev, "no platform data\n");
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return -ENODEV;
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}
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if (pdata->max_uA < isink_cur[0]) {
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dev_err(&pdev->dev, "Invalid maximum current %duA\n",
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pdata->max_uA);
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return -EINVAL;
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}
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isink = regulator_get(&pdev->dev, "led_isink");
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if (IS_ERR(isink)) {
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printk(KERN_ERR "%s: can't get ISINK\n", __func__);
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return PTR_ERR(isink);
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}
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dcdc = regulator_get(&pdev->dev, "led_vcc");
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if (IS_ERR(dcdc)) {
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printk(KERN_ERR "%s: can't get DCDC\n", __func__);
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ret = PTR_ERR(dcdc);
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goto err_isink;
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}
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led = kzalloc(sizeof(*led), GFP_KERNEL);
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if (led == NULL) {
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ret = -ENOMEM;
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goto err_dcdc;
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}
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led->cdev.brightness_set = wm8350_led_set;
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led->cdev.default_trigger = pdata->default_trigger;
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led->cdev.name = pdata->name;
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led->cdev.flags |= LED_CORE_SUSPENDRESUME;
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led->enabled = regulator_is_enabled(isink);
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led->isink = isink;
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led->dcdc = dcdc;
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for (i = 0; i < ARRAY_SIZE(isink_cur) - 1; i++)
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if (isink_cur[i] >= pdata->max_uA)
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break;
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led->max_uA_index = i;
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if (pdata->max_uA != isink_cur[i])
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dev_warn(&pdev->dev,
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"Maximum current %duA is not directly supported,"
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" check platform data\n",
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pdata->max_uA);
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spin_lock_init(&led->value_lock);
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mutex_init(&led->mutex);
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INIT_WORK(&led->work, led_work);
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led->value = LED_OFF;
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platform_set_drvdata(pdev, led);
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ret = led_classdev_register(&pdev->dev, &led->cdev);
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if (ret < 0)
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goto err_led;
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return 0;
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err_led:
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kfree(led);
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err_dcdc:
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regulator_put(dcdc);
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err_isink:
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regulator_put(isink);
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return ret;
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}
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static int wm8350_led_remove(struct platform_device *pdev)
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{
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struct wm8350_led *led = platform_get_drvdata(pdev);
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led_classdev_unregister(&led->cdev);
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flush_work_sync(&led->work);
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wm8350_led_disable(led);
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regulator_put(led->dcdc);
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regulator_put(led->isink);
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kfree(led);
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return 0;
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}
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static struct platform_driver wm8350_led_driver = {
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.driver = {
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.name = "wm8350-led",
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.owner = THIS_MODULE,
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},
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.probe = wm8350_led_probe,
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.remove = wm8350_led_remove,
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.shutdown = wm8350_led_shutdown,
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};
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module_platform_driver(wm8350_led_driver);
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MODULE_AUTHOR("Mark Brown");
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MODULE_DESCRIPTION("WM8350 LED driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:wm8350-led");
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