1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Backlight driver for OMAP based boards.
4 *
5 * Copyright (c) 2006 Andrzej Zaborowski  <balrog@zabor.org>
6 */
7
8#include <linux/module.h>
9#include <linux/kernel.h>
10#include <linux/init.h>
11#include <linux/platform_device.h>
12#include <linux/fb.h>
13#include <linux/backlight.h>
14#include <linux/slab.h>
15#include <linux/platform_data/omap1_bl.h>
16
17#include <linux/soc/ti/omap1-io.h>
18#include <linux/soc/ti/omap1-mux.h>
19
20#define OMAPBL_MAX_INTENSITY		0xff
21
22struct omap_backlight {
23	int powermode;
24	int current_intensity;
25
26	struct device *dev;
27	struct omap_backlight_config *pdata;
28};
29
30static inline void omapbl_send_intensity(int intensity)
31{
32	omap_writeb(intensity, OMAP_PWL_ENABLE);
33}
34
35static inline void omapbl_send_enable(int enable)
36{
37	omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
38}
39
40static void omapbl_blank(struct omap_backlight *bl, int mode)
41{
42	if (bl->pdata->set_power)
43		bl->pdata->set_power(bl->dev, mode);
44
45	switch (mode) {
46	case FB_BLANK_NORMAL:
47	case FB_BLANK_VSYNC_SUSPEND:
48	case FB_BLANK_HSYNC_SUSPEND:
49	case FB_BLANK_POWERDOWN:
50		omapbl_send_intensity(0);
51		omapbl_send_enable(0);
52		break;
53
54	case FB_BLANK_UNBLANK:
55		omapbl_send_intensity(bl->current_intensity);
56		omapbl_send_enable(1);
57		break;
58	}
59}
60
61#ifdef CONFIG_PM_SLEEP
62static int omapbl_suspend(struct device *dev)
63{
64	struct backlight_device *bl_dev = dev_get_drvdata(dev);
65	struct omap_backlight *bl = bl_get_data(bl_dev);
66
67	omapbl_blank(bl, FB_BLANK_POWERDOWN);
68	return 0;
69}
70
71static int omapbl_resume(struct device *dev)
72{
73	struct backlight_device *bl_dev = dev_get_drvdata(dev);
74	struct omap_backlight *bl = bl_get_data(bl_dev);
75
76	omapbl_blank(bl, bl->powermode);
77	return 0;
78}
79#endif
80
81static int omapbl_set_power(struct backlight_device *dev, int state)
82{
83	struct omap_backlight *bl = bl_get_data(dev);
84
85	omapbl_blank(bl, state);
86	bl->powermode = state;
87
88	return 0;
89}
90
91static int omapbl_update_status(struct backlight_device *dev)
92{
93	struct omap_backlight *bl = bl_get_data(dev);
94
95	if (bl->current_intensity != dev->props.brightness) {
96		if (bl->powermode == FB_BLANK_UNBLANK)
97			omapbl_send_intensity(dev->props.brightness);
98		bl->current_intensity = dev->props.brightness;
99	}
100
101	if (dev->props.fb_blank != bl->powermode)
102		omapbl_set_power(dev, dev->props.fb_blank);
103
104	return 0;
105}
106
107static int omapbl_get_intensity(struct backlight_device *dev)
108{
109	struct omap_backlight *bl = bl_get_data(dev);
110
111	return bl->current_intensity;
112}
113
114static const struct backlight_ops omapbl_ops = {
115	.get_brightness = omapbl_get_intensity,
116	.update_status  = omapbl_update_status,
117};
118
119static int omapbl_probe(struct platform_device *pdev)
120{
121	struct backlight_properties props;
122	struct backlight_device *dev;
123	struct omap_backlight *bl;
124	struct omap_backlight_config *pdata = dev_get_platdata(&pdev->dev);
125
126	if (!pdata)
127		return -ENXIO;
128
129	bl = devm_kzalloc(&pdev->dev, sizeof(struct omap_backlight),
130			  GFP_KERNEL);
131	if (unlikely(!bl))
132		return -ENOMEM;
133
134	memset(&props, 0, sizeof(struct backlight_properties));
135	props.type = BACKLIGHT_RAW;
136	props.max_brightness = OMAPBL_MAX_INTENSITY;
137	dev = devm_backlight_device_register(&pdev->dev, "omap-bl", &pdev->dev,
138					bl, &omapbl_ops, &props);
139	if (IS_ERR(dev))
140		return PTR_ERR(dev);
141
142	bl->powermode = FB_BLANK_POWERDOWN;
143	bl->current_intensity = 0;
144
145	bl->pdata = pdata;
146	bl->dev = &pdev->dev;
147
148	platform_set_drvdata(pdev, dev);
149
150	omap_cfg_reg(PWL);	/* Conflicts with UART3 */
151
152	dev->props.fb_blank = FB_BLANK_UNBLANK;
153	dev->props.brightness = pdata->default_intensity;
154	omapbl_update_status(dev);
155
156	dev_info(&pdev->dev, "OMAP LCD backlight initialised\n");
157
158	return 0;
159}
160
161static SIMPLE_DEV_PM_OPS(omapbl_pm_ops, omapbl_suspend, omapbl_resume);
162
163static struct platform_driver omapbl_driver = {
164	.probe		= omapbl_probe,
165	.driver		= {
166		.name	= "omap-bl",
167		.pm	= &omapbl_pm_ops,
168	},
169};
170
171module_platform_driver(omapbl_driver);
172
173MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
174MODULE_DESCRIPTION("OMAP LCD Backlight driver");
175MODULE_LICENSE("GPL");
176