kernel/drivers/gpu/drm/shmobile/shmob_drm_backlight.c

   1 /*
   2  * shmob_drm_backlight.c  --  SH Mobile DRM Backlight
   3  *
   4  * Copyright (C) 2012 Renesas Electronics Corporation
   5  *
   6  * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  */
  13
  14 #include <linux/backlight.h>
  15
  16 #include "shmob_drm_backlight.h"
  17 #include "shmob_drm_crtc.h"
  18 #include "shmob_drm_drv.h"
  19
  20 static int shmob_drm_backlight_update(struct backlight_device *bdev)
  21 {
  22         struct shmob_drm_connector *scon = bl_get_data(bdev);
  23         struct shmob_drm_device *sdev = scon->connector.dev->dev_private;
  24         const struct shmob_drm_backlight_data *bdata = &sdev->pdata->backlight;
  25         int brightness = bdev->props.brightness;
  26
  27         if (bdev->props.power != FB_BLANK_UNBLANK ||
  28             bdev->props.state & BL_CORE_SUSPENDED)
  29                 brightness = 0;
  30
  31         return bdata->set_brightness(brightness);
  32 }
  33
  34 static int shmob_drm_backlight_get_brightness(struct backlight_device *bdev)
  35 {
  36         struct shmob_drm_connector *scon = bl_get_data(bdev);
  37         struct shmob_drm_device *sdev = scon->connector.dev->dev_private;
  38         const struct shmob_drm_backlight_data *bdata = &sdev->pdata->backlight;
  39
  40         return bdata->get_brightness();
  41 }
  42
  43 static const struct backlight_ops shmob_drm_backlight_ops = {
  44         .options        = BL_CORE_SUSPENDRESUME,
  45         .update_status  = shmob_drm_backlight_update,
  46         .get_brightness = shmob_drm_backlight_get_brightness,
  47 };
  48
  49 void shmob_drm_backlight_dpms(struct shmob_drm_connector *scon, int mode)
  50 {
  51         if (scon->backlight == NULL)
  52                 return;
  53
  54         scon->backlight->props.power = mode == DRM_MODE_DPMS_ON
  55                                      ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
  56         backlight_update_status(scon->backlight);
  57 }
  58
  59 int shmob_drm_backlight_init(struct shmob_drm_connector *scon)
  60 {
  61         struct shmob_drm_device *sdev = scon->connector.dev->dev_private;
  62         const struct shmob_drm_backlight_data *bdata = &sdev->pdata->backlight;
  63         struct drm_connector *connector = &scon->connector;
  64         struct drm_device *dev = connector->dev;
  65         struct backlight_device *backlight;
  66
  67         if (!bdata->max_brightness)
  68                 return 0;
  69
  70         backlight = backlight_device_register(bdata->name, dev->dev, scon,
  71                                               &shmob_drm_backlight_ops, NULL);
  72         if (IS_ERR(backlight)) {
  73                 dev_err(dev->dev, "unable to register backlight device: %ld\n",
  74                         PTR_ERR(backlight));
  75                 return PTR_ERR(backlight);
  76         }
  77
  78         backlight->props.max_brightness = bdata->max_brightness;
  79         backlight->props.brightness = bdata->max_brightness;
  80         backlight->props.power = FB_BLANK_POWERDOWN;
  81         backlight_update_status(backlight);
  82
  83         scon->backlight = backlight;
  84         return 0;
  85 }
  86
  87 void shmob_drm_backlight_exit(struct shmob_drm_connector *scon)
  88 {
  89         backlight_device_unregister(scon->backlight);
  90 }