156 lines
3.9 KiB
C
156 lines
3.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
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* PCF50633 backlight device driver
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/platform_device.h>
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#include <linux/backlight.h>
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#include <linux/fb.h>
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#include <linux/mfd/pcf50633/core.h>
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#include <linux/mfd/pcf50633/backlight.h>
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struct pcf50633_bl {
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struct pcf50633 *pcf;
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struct backlight_device *bl;
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unsigned int brightness;
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unsigned int brightness_limit;
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};
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/*
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* pcf50633_bl_set_brightness_limit
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*
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* Update the brightness limit for the pc50633 backlight. The actual brightness
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* will not go above the limit. This is useful to limit power drain for example
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* on low battery.
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*
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* @dev: Pointer to a pcf50633 device
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* @limit: The brightness limit. Valid values are 0-63
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*/
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int pcf50633_bl_set_brightness_limit(struct pcf50633 *pcf, unsigned int limit)
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{
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struct pcf50633_bl *pcf_bl = platform_get_drvdata(pcf->bl_pdev);
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if (!pcf_bl)
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return -ENODEV;
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pcf_bl->brightness_limit = limit & 0x3f;
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backlight_update_status(pcf_bl->bl);
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return 0;
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}
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static int pcf50633_bl_update_status(struct backlight_device *bl)
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{
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struct pcf50633_bl *pcf_bl = bl_get_data(bl);
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unsigned int new_brightness;
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if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK) ||
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bl->props.power != FB_BLANK_UNBLANK)
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new_brightness = 0;
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else if (bl->props.brightness < pcf_bl->brightness_limit)
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new_brightness = bl->props.brightness;
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else
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new_brightness = pcf_bl->brightness_limit;
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if (pcf_bl->brightness == new_brightness)
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return 0;
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if (new_brightness) {
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pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDOUT,
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new_brightness);
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if (!pcf_bl->brightness)
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pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDENA, 1);
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} else {
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pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDENA, 0);
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}
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pcf_bl->brightness = new_brightness;
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return 0;
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}
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static int pcf50633_bl_get_brightness(struct backlight_device *bl)
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{
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struct pcf50633_bl *pcf_bl = bl_get_data(bl);
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return pcf_bl->brightness;
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}
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static const struct backlight_ops pcf50633_bl_ops = {
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.get_brightness = pcf50633_bl_get_brightness,
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.update_status = pcf50633_bl_update_status,
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.options = BL_CORE_SUSPENDRESUME,
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};
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static int pcf50633_bl_probe(struct platform_device *pdev)
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{
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struct pcf50633_bl *pcf_bl;
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struct device *parent = pdev->dev.parent;
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struct pcf50633_platform_data *pcf50633_data = dev_get_platdata(parent);
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struct pcf50633_bl_platform_data *pdata = pcf50633_data->backlight_data;
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struct backlight_properties bl_props;
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pcf_bl = devm_kzalloc(&pdev->dev, sizeof(*pcf_bl), GFP_KERNEL);
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if (!pcf_bl)
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return -ENOMEM;
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memset(&bl_props, 0, sizeof(bl_props));
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bl_props.type = BACKLIGHT_RAW;
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bl_props.max_brightness = 0x3f;
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bl_props.power = FB_BLANK_UNBLANK;
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if (pdata) {
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bl_props.brightness = pdata->default_brightness;
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pcf_bl->brightness_limit = pdata->default_brightness_limit;
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} else {
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bl_props.brightness = 0x3f;
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pcf_bl->brightness_limit = 0x3f;
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}
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pcf_bl->pcf = dev_to_pcf50633(pdev->dev.parent);
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pcf_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name,
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&pdev->dev, pcf_bl,
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&pcf50633_bl_ops, &bl_props);
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if (IS_ERR(pcf_bl->bl))
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return PTR_ERR(pcf_bl->bl);
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platform_set_drvdata(pdev, pcf_bl);
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pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDDIM, pdata->ramp_time);
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/*
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* Should be different from bl_props.brightness, so we do not exit
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* update_status early the first time it's called
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*/
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pcf_bl->brightness = pcf_bl->bl->props.brightness + 1;
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backlight_update_status(pcf_bl->bl);
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return 0;
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}
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static struct platform_driver pcf50633_bl_driver = {
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.probe = pcf50633_bl_probe,
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.driver = {
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.name = "pcf50633-backlight",
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},
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};
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module_platform_driver(pcf50633_bl_driver);
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MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
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MODULE_DESCRIPTION("PCF50633 backlight driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:pcf50633-backlight");
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