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