linuxdebug/drivers/hid/hid-picolcd_backlight.c

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2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/***************************************************************************
* Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org> *
* *
* Based on Logitech G13 driver (v0.4) *
* Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu> *
* *
***************************************************************************/
#include <linux/hid.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include "hid-picolcd.h"
static int picolcd_get_brightness(struct backlight_device *bdev)
{
struct picolcd_data *data = bl_get_data(bdev);
return data->lcd_brightness;
}
static int picolcd_set_brightness(struct backlight_device *bdev)
{
struct picolcd_data *data = bl_get_data(bdev);
struct hid_report *report = picolcd_out_report(REPORT_BRIGHTNESS, data->hdev);
unsigned long flags;
if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
return -ENODEV;
data->lcd_brightness = bdev->props.brightness & 0x0ff;
data->lcd_power = bdev->props.power;
spin_lock_irqsave(&data->lock, flags);
hid_set_field(report->field[0], 0, data->lcd_power == FB_BLANK_UNBLANK ? data->lcd_brightness : 0);
if (!(data->status & PICOLCD_FAILED))
hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
spin_unlock_irqrestore(&data->lock, flags);
return 0;
}
static int picolcd_check_bl_fb(struct backlight_device *bdev, struct fb_info *fb)
{
return fb && fb == picolcd_fbinfo((struct picolcd_data *)bl_get_data(bdev));
}
static const struct backlight_ops picolcd_blops = {
.update_status = picolcd_set_brightness,
.get_brightness = picolcd_get_brightness,
.check_fb = picolcd_check_bl_fb,
};
int picolcd_init_backlight(struct picolcd_data *data, struct hid_report *report)
{
struct device *dev = &data->hdev->dev;
struct backlight_device *bdev;
struct backlight_properties props;
if (!report)
return -ENODEV;
if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
report->field[0]->report_size != 8) {
dev_err(dev, "unsupported BRIGHTNESS report");
return -EINVAL;
}
memset(&props, 0, sizeof(props));
props.type = BACKLIGHT_RAW;
props.max_brightness = 0xff;
bdev = backlight_device_register(dev_name(dev), dev, data,
&picolcd_blops, &props);
if (IS_ERR(bdev)) {
dev_err(dev, "failed to register backlight\n");
return PTR_ERR(bdev);
}
bdev->props.brightness = 0xff;
data->lcd_brightness = 0xff;
data->backlight = bdev;
picolcd_set_brightness(bdev);
return 0;
}
void picolcd_exit_backlight(struct picolcd_data *data)
{
struct backlight_device *bdev = data->backlight;
data->backlight = NULL;
backlight_device_unregister(bdev);
}
int picolcd_resume_backlight(struct picolcd_data *data)
{
if (!data->backlight)
return 0;
return picolcd_set_brightness(data->backlight);
}
#ifdef CONFIG_PM
void picolcd_suspend_backlight(struct picolcd_data *data)
{
int bl_power = data->lcd_power;
if (!data->backlight)
return;
data->backlight->props.power = FB_BLANK_POWERDOWN;
picolcd_set_brightness(data->backlight);
data->lcd_power = data->backlight->props.power = bl_power;
}
#endif /* CONFIG_PM */