1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * shmob_drm_backlight.c -- SH Mobile DRM Backlight
4 *
5 * Copyright (C) 2012 Renesas Electronics Corporation
6 *
7 * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
8 */
9
10 #include <linux/backlight.h>
11
12 #include "shmob_drm_backlight.h"
13 #include "shmob_drm_crtc.h"
14 #include "shmob_drm_drv.h"
15
shmob_drm_backlight_update(struct backlight_device * bdev)16 static int shmob_drm_backlight_update(struct backlight_device *bdev)
17 {
18 struct shmob_drm_connector *scon = bl_get_data(bdev);
19 struct shmob_drm_device *sdev = scon->connector.dev->dev_private;
20 const struct shmob_drm_backlight_data *bdata = &sdev->pdata->backlight;
21 int brightness = bdev->props.brightness;
22
23 if (bdev->props.power != FB_BLANK_UNBLANK ||
24 bdev->props.state & BL_CORE_SUSPENDED)
25 brightness = 0;
26
27 return bdata->set_brightness(brightness);
28 }
29
shmob_drm_backlight_get_brightness(struct backlight_device * bdev)30 static int shmob_drm_backlight_get_brightness(struct backlight_device *bdev)
31 {
32 struct shmob_drm_connector *scon = bl_get_data(bdev);
33 struct shmob_drm_device *sdev = scon->connector.dev->dev_private;
34 const struct shmob_drm_backlight_data *bdata = &sdev->pdata->backlight;
35
36 return bdata->get_brightness();
37 }
38
39 static const struct backlight_ops shmob_drm_backlight_ops = {
40 .options = BL_CORE_SUSPENDRESUME,
41 .update_status = shmob_drm_backlight_update,
42 .get_brightness = shmob_drm_backlight_get_brightness,
43 };
44
shmob_drm_backlight_dpms(struct shmob_drm_connector * scon,int mode)45 void shmob_drm_backlight_dpms(struct shmob_drm_connector *scon, int mode)
46 {
47 if (scon->backlight == NULL)
48 return;
49
50 scon->backlight->props.power = mode == DRM_MODE_DPMS_ON
51 ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
52 backlight_update_status(scon->backlight);
53 }
54
shmob_drm_backlight_init(struct shmob_drm_connector * scon)55 int shmob_drm_backlight_init(struct shmob_drm_connector *scon)
56 {
57 struct shmob_drm_device *sdev = scon->connector.dev->dev_private;
58 const struct shmob_drm_backlight_data *bdata = &sdev->pdata->backlight;
59 struct drm_connector *connector = &scon->connector;
60 struct drm_device *dev = connector->dev;
61 struct backlight_device *backlight;
62
63 if (!bdata->max_brightness)
64 return 0;
65
66 backlight = backlight_device_register(bdata->name, dev->dev, scon,
67 &shmob_drm_backlight_ops, NULL);
68 if (IS_ERR(backlight)) {
69 dev_err(dev->dev, "unable to register backlight device: %ld\n",
70 PTR_ERR(backlight));
71 return PTR_ERR(backlight);
72 }
73
74 backlight->props.max_brightness = bdata->max_brightness;
75 backlight->props.brightness = bdata->max_brightness;
76 backlight->props.power = FB_BLANK_POWERDOWN;
77 backlight_update_status(backlight);
78
79 scon->backlight = backlight;
80 return 0;
81 }
82
shmob_drm_backlight_exit(struct shmob_drm_connector * scon)83 void shmob_drm_backlight_exit(struct shmob_drm_connector *scon)
84 {
85 backlight_device_unregister(scon->backlight);
86 }
87