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 <mach/hardware.h>
18 #include <mach/mux.h>
19
20 #define OMAPBL_MAX_INTENSITY 0xff
21
22 struct omap_backlight {
23 int powermode;
24 int current_intensity;
25
26 struct device *dev;
27 struct omap_backlight_config *pdata;
28 };
29
omapbl_send_intensity(int intensity)30 static inline void omapbl_send_intensity(int intensity)
31 {
32 omap_writeb(intensity, OMAP_PWL_ENABLE);
33 }
34
omapbl_send_enable(int enable)35 static inline void omapbl_send_enable(int enable)
36 {
37 omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
38 }
39
omapbl_blank(struct omap_backlight * bl,int mode)40 static 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
omapbl_suspend(struct device * dev)62 static 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
omapbl_resume(struct device * dev)71 static 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
omapbl_set_power(struct backlight_device * dev,int state)81 static 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
omapbl_update_status(struct backlight_device * dev)91 static 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
omapbl_get_intensity(struct backlight_device * dev)107 static 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
114 static const struct backlight_ops omapbl_ops = {
115 .get_brightness = omapbl_get_intensity,
116 .update_status = omapbl_update_status,
117 };
118
omapbl_probe(struct platform_device * pdev)119 static 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
161 static SIMPLE_DEV_PM_OPS(omapbl_pm_ops, omapbl_suspend, omapbl_resume);
162
163 static struct platform_driver omapbl_driver = {
164 .probe = omapbl_probe,
165 .driver = {
166 .name = "omap-bl",
167 .pm = &omapbl_pm_ops,
168 },
169 };
170
171 module_platform_driver(omapbl_driver);
172
173 MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
174 MODULE_DESCRIPTION("OMAP LCD Backlight driver");
175 MODULE_LICENSE("GPL");
176