![Emese Revfy](/assets/img/avatar_default.png)
Signed-off-by: Emese Revfy <re.emese@gmail.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
251 lines
6 KiB
C
251 lines
6 KiB
C
/*
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* Backlight driver for Wolfson Microelectronics WM831x PMICs
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*
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* Copyright 2009 Wolfson Microelectonics 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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#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/fb.h>
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#include <linux/backlight.h>
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#include <linux/mfd/wm831x/core.h>
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#include <linux/mfd/wm831x/pdata.h>
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#include <linux/mfd/wm831x/regulator.h>
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struct wm831x_backlight_data {
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struct wm831x *wm831x;
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int isink_reg;
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int current_brightness;
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};
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static int wm831x_backlight_set(struct backlight_device *bl, int brightness)
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{
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struct wm831x_backlight_data *data = bl_get_data(bl);
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struct wm831x *wm831x = data->wm831x;
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int power_up = !data->current_brightness && brightness;
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int power_down = data->current_brightness && !brightness;
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int ret;
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if (power_up) {
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/* Enable the ISINK */
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ret = wm831x_set_bits(wm831x, data->isink_reg,
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WM831X_CS1_ENA, WM831X_CS1_ENA);
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if (ret < 0)
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goto err;
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/* Enable the DC-DC */
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ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE,
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WM831X_DC4_ENA, WM831X_DC4_ENA);
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if (ret < 0)
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goto err;
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}
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if (power_down) {
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/* DCDC first */
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ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE,
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WM831X_DC4_ENA, 0);
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if (ret < 0)
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goto err;
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/* ISINK */
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ret = wm831x_set_bits(wm831x, data->isink_reg,
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WM831X_CS1_DRIVE | WM831X_CS1_ENA, 0);
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if (ret < 0)
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goto err;
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}
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/* Set the new brightness */
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ret = wm831x_set_bits(wm831x, data->isink_reg,
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WM831X_CS1_ISEL_MASK, brightness);
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if (ret < 0)
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goto err;
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if (power_up) {
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/* Drive current through the ISINK */
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ret = wm831x_set_bits(wm831x, data->isink_reg,
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WM831X_CS1_DRIVE, WM831X_CS1_DRIVE);
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if (ret < 0)
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return ret;
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}
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data->current_brightness = brightness;
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return 0;
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err:
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/* If we were in the middle of a power transition always shut down
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* for safety.
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*/
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if (power_up || power_down) {
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wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0);
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wm831x_set_bits(wm831x, data->isink_reg, WM831X_CS1_ENA, 0);
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}
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return ret;
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}
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static int wm831x_backlight_update_status(struct backlight_device *bl)
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{
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int brightness = bl->props.brightness;
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if (bl->props.power != FB_BLANK_UNBLANK)
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brightness = 0;
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if (bl->props.fb_blank != FB_BLANK_UNBLANK)
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brightness = 0;
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if (bl->props.state & BL_CORE_SUSPENDED)
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brightness = 0;
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return wm831x_backlight_set(bl, brightness);
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}
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static int wm831x_backlight_get_brightness(struct backlight_device *bl)
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{
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struct wm831x_backlight_data *data = bl_get_data(bl);
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return data->current_brightness;
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}
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static const struct backlight_ops wm831x_backlight_ops = {
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.options = BL_CORE_SUSPENDRESUME,
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.update_status = wm831x_backlight_update_status,
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.get_brightness = wm831x_backlight_get_brightness,
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};
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static int wm831x_backlight_probe(struct platform_device *pdev)
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{
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struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
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struct wm831x_pdata *wm831x_pdata;
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struct wm831x_backlight_pdata *pdata;
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struct wm831x_backlight_data *data;
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struct backlight_device *bl;
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int ret, i, max_isel, isink_reg, dcdc_cfg;
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/* We need platform data */
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if (pdev->dev.parent->platform_data) {
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wm831x_pdata = pdev->dev.parent->platform_data;
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pdata = wm831x_pdata->backlight;
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} else {
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pdata = NULL;
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}
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if (!pdata) {
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dev_err(&pdev->dev, "No platform data supplied\n");
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return -EINVAL;
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}
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/* Figure out the maximum current we can use */
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for (i = 0; i < WM831X_ISINK_MAX_ISEL; i++) {
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if (wm831x_isinkv_values[i] > pdata->max_uA)
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break;
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}
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if (i == 0) {
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dev_err(&pdev->dev, "Invalid max_uA: %duA\n", pdata->max_uA);
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return -EINVAL;
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}
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max_isel = i - 1;
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if (pdata->max_uA != wm831x_isinkv_values[max_isel])
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dev_warn(&pdev->dev,
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"Maximum current is %duA not %duA as requested\n",
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wm831x_isinkv_values[max_isel], pdata->max_uA);
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switch (pdata->isink) {
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case 1:
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isink_reg = WM831X_CURRENT_SINK_1;
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dcdc_cfg = 0;
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break;
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case 2:
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isink_reg = WM831X_CURRENT_SINK_2;
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dcdc_cfg = WM831X_DC4_FBSRC;
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break;
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default:
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dev_err(&pdev->dev, "Invalid ISINK %d\n", pdata->isink);
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return -EINVAL;
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}
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/* Configure the ISINK to use for feedback */
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ret = wm831x_reg_unlock(wm831x);
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if (ret < 0)
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return ret;
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ret = wm831x_set_bits(wm831x, WM831X_DC4_CONTROL, WM831X_DC4_FBSRC,
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dcdc_cfg);
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wm831x_reg_lock(wm831x);
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if (ret < 0)
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return ret;
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data = kzalloc(sizeof(*data), GFP_KERNEL);
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if (data == NULL)
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return -ENOMEM;
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data->wm831x = wm831x;
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data->current_brightness = 0;
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data->isink_reg = isink_reg;
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bl = backlight_device_register("wm831x", &pdev->dev,
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data, &wm831x_backlight_ops);
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if (IS_ERR(bl)) {
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dev_err(&pdev->dev, "failed to register backlight\n");
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kfree(data);
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return PTR_ERR(bl);
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}
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bl->props.max_brightness = max_isel;
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bl->props.brightness = max_isel;
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platform_set_drvdata(pdev, bl);
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/* Disable the DCDC if it was started so we can bootstrap */
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wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0);
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backlight_update_status(bl);
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return 0;
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}
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static int wm831x_backlight_remove(struct platform_device *pdev)
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{
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struct backlight_device *bl = platform_get_drvdata(pdev);
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struct wm831x_backlight_data *data = bl_get_data(bl);
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backlight_device_unregister(bl);
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kfree(data);
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return 0;
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}
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static struct platform_driver wm831x_backlight_driver = {
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.driver = {
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.name = "wm831x-backlight",
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.owner = THIS_MODULE,
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},
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.probe = wm831x_backlight_probe,
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.remove = wm831x_backlight_remove,
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};
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static int __init wm831x_backlight_init(void)
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{
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return platform_driver_register(&wm831x_backlight_driver);
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}
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module_init(wm831x_backlight_init);
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static void __exit wm831x_backlight_exit(void)
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{
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platform_driver_unregister(&wm831x_backlight_driver);
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}
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module_exit(wm831x_backlight_exit);
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MODULE_DESCRIPTION("Backlight Driver for WM831x PMICs");
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MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:wm831x-backlight");
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