LXR linux/drivers/hid/hid-picolcd

   1// SPDX-License-Identifier: GPL-2.0-only
   2/***************************************************************************
   3 *   Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org>  *
   4 *                                                                         *
   5 *   Based on Logitech G13 driver (v0.4)                                   *
   6 *     Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu>   *
   7 *                                                                         *
   8 ***************************************************************************/
   9
  10#include <linux/hid.h>
  11
  12#include <linux/fb.h>
  13#include <linux/backlight.h>
  14
  15#include "hid-picolcd.h"
  16
  17static int picolcd_get_brightness(struct backlight_device *bdev)
  18{
  19        struct picolcd_data *data = bl_get_data(bdev);
  20        return data->lcd_brightness;
  21}
  22
  23static int picolcd_set_brightness(struct backlight_device *bdev)
  24{
  25        struct picolcd_data *data = bl_get_data(bdev);
  26        struct hid_report *report = picolcd_out_report(REPORT_BRIGHTNESS, data->hdev);
  27        unsigned long flags;
  28
  29        if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
  30                return -ENODEV;
  31
  32        data->lcd_brightness = bdev->props.brightness & 0x0ff;
  33        data->lcd_power      = bdev->props.power;
  34        spin_lock_irqsave(&data->lock, flags);
  35        hid_set_field(report->field[0], 0, data->lcd_power == FB_BLANK_UNBLANK ? data->lcd_brightness : 0);
  36        if (!(data->status & PICOLCD_FAILED))
  37                hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
  38        spin_unlock_irqrestore(&data->lock, flags);
  39        return 0;
  40}
  41
  42static int picolcd_check_bl_fb(struct backlight_device *bdev, struct fb_info *fb)
  43{
  44        return fb && fb == picolcd_fbinfo((struct picolcd_data *)bl_get_data(bdev));
  45}
  46
  47static const struct backlight_ops picolcd_blops = {
  48        .update_status  = picolcd_set_brightness,
  49        .get_brightness = picolcd_get_brightness,
  50        .check_fb       = picolcd_check_bl_fb,
  51};
  52
  53int picolcd_init_backlight(struct picolcd_data *data, struct hid_report *report)
  54{
  55        struct device *dev = &data->hdev->dev;
  56        struct backlight_device *bdev;
  57        struct backlight_properties props;
  58        if (!report)
  59                return -ENODEV;
  60        if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
  61                        report->field[0]->report_size != 8) {
  62                dev_err(dev, "unsupported BRIGHTNESS report");
  63                return -EINVAL;
  64        }
  65
  66        memset(&props, 0, sizeof(props));
  67        props.type = BACKLIGHT_RAW;
  68        props.max_brightness = 0xff;
  69        bdev = backlight_device_register(dev_name(dev), dev, data,
  70                        &picolcd_blops, &props);
  71        if (IS_ERR(bdev)) {
  72                dev_err(dev, "failed to register backlight\n");
  73                return PTR_ERR(bdev);
  74        }
  75        bdev->props.brightness     = 0xff;
  76        data->lcd_brightness       = 0xff;
  77        data->backlight            = bdev;
  78        picolcd_set_brightness(bdev);
  79        return 0;
  80}
  81
  82void picolcd_exit_backlight(struct picolcd_data *data)
  83{
  84        struct backlight_device *bdev = data->backlight;
  85
  86        data->backlight = NULL;
  87        backlight_device_unregister(bdev);
  88}
  89
  90int picolcd_resume_backlight(struct picolcd_data *data)
  91{
  92        if (!data->backlight)
  93                return 0;
  94        return picolcd_set_brightness(data->backlight);
  95}
  96
  97#ifdef CONFIG_PM
  98void picolcd_suspend_backlight(struct picolcd_data *data)
  99{
 100        int bl_power = data->lcd_power;
 101        if (!data->backlight)
 102                return;
 103
 104        data->backlight->props.power = FB_BLANK_POWERDOWN;
 105        picolcd_set_brightness(data->backlight);
 106        data->lcd_power = data->backlight->props.power = bl_power;
 107}
 108#endif /* CONFIG_PM */
 109
 110