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155 lines
3.9 KiB
155 lines
3.9 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Copyright (C) 2009-2010, Lars-Peter Clausen <[email protected]> |
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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 <[email protected]>"); |
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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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