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
16static 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
30static 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
39static 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
45void 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
55int 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
83void shmob_drm_backlight_exit(struct shmob_drm_connector *scon)
84{
85	backlight_device_unregister(scon->backlight);
86}