linux/drivers/video/backlight/pcf50633-backlight.c
Thomas Gleixner a912e80bd0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 151
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version you should have received a copy of the
  gnu general public license along with this program if not write to
  the free software foundation inc 675 mass ave cambridge ma 02139 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 35 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.655028468@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:28 -07:00

156 lines
3.9 KiB
C

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