1 // SPDX-License-Identifier: GPL-2.0-only
2 /* drivers/video/backlight/platform_lcd.c
3 *
4 * Copyright 2008 Simtec Electronics
5 * Ben Dooks <ben@simtec.co.uk>
6 *
7 * Generic platform-device LCD power control interface.
8 */
9
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/fb.h>
13 #include <linux/backlight.h>
14 #include <linux/lcd.h>
15 #include <linux/of.h>
16 #include <linux/slab.h>
17
18 #include <video/platform_lcd.h>
19
20 struct platform_lcd {
21 struct device *us;
22 struct lcd_device *lcd;
23 struct plat_lcd_data *pdata;
24
25 unsigned int power;
26 unsigned int suspended:1;
27 };
28
to_our_lcd(struct lcd_device * lcd)29 static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
30 {
31 return lcd_get_data(lcd);
32 }
33
platform_lcd_get_power(struct lcd_device * lcd)34 static int platform_lcd_get_power(struct lcd_device *lcd)
35 {
36 struct platform_lcd *plcd = to_our_lcd(lcd);
37
38 return plcd->power;
39 }
40
platform_lcd_set_power(struct lcd_device * lcd,int power)41 static int platform_lcd_set_power(struct lcd_device *lcd, int power)
42 {
43 struct platform_lcd *plcd = to_our_lcd(lcd);
44 int lcd_power = 1;
45
46 if (power == FB_BLANK_POWERDOWN || plcd->suspended)
47 lcd_power = 0;
48
49 plcd->pdata->set_power(plcd->pdata, lcd_power);
50 plcd->power = power;
51
52 return 0;
53 }
54
platform_lcd_match(struct lcd_device * lcd,struct fb_info * info)55 static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info)
56 {
57 struct platform_lcd *plcd = to_our_lcd(lcd);
58 struct plat_lcd_data *pdata = plcd->pdata;
59
60 if (pdata->match_fb)
61 return pdata->match_fb(pdata, info);
62
63 return plcd->us->parent == info->device;
64 }
65
66 static struct lcd_ops platform_lcd_ops = {
67 .get_power = platform_lcd_get_power,
68 .set_power = platform_lcd_set_power,
69 .check_fb = platform_lcd_match,
70 };
71
platform_lcd_probe(struct platform_device * pdev)72 static int platform_lcd_probe(struct platform_device *pdev)
73 {
74 struct plat_lcd_data *pdata;
75 struct platform_lcd *plcd;
76 struct device *dev = &pdev->dev;
77 int err;
78
79 pdata = dev_get_platdata(&pdev->dev);
80 if (!pdata) {
81 dev_err(dev, "no platform data supplied\n");
82 return -EINVAL;
83 }
84
85 if (pdata->probe) {
86 err = pdata->probe(pdata);
87 if (err)
88 return err;
89 }
90
91 plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd),
92 GFP_KERNEL);
93 if (!plcd)
94 return -ENOMEM;
95
96 plcd->us = dev;
97 plcd->pdata = pdata;
98 plcd->lcd = devm_lcd_device_register(&pdev->dev, dev_name(dev), dev,
99 plcd, &platform_lcd_ops);
100 if (IS_ERR(plcd->lcd)) {
101 dev_err(dev, "cannot register lcd device\n");
102 return PTR_ERR(plcd->lcd);
103 }
104
105 platform_set_drvdata(pdev, plcd);
106 platform_lcd_set_power(plcd->lcd, FB_BLANK_NORMAL);
107
108 return 0;
109 }
110
111 #ifdef CONFIG_PM_SLEEP
platform_lcd_suspend(struct device * dev)112 static int platform_lcd_suspend(struct device *dev)
113 {
114 struct platform_lcd *plcd = dev_get_drvdata(dev);
115
116 plcd->suspended = 1;
117 platform_lcd_set_power(plcd->lcd, plcd->power);
118
119 return 0;
120 }
121
platform_lcd_resume(struct device * dev)122 static int platform_lcd_resume(struct device *dev)
123 {
124 struct platform_lcd *plcd = dev_get_drvdata(dev);
125
126 plcd->suspended = 0;
127 platform_lcd_set_power(plcd->lcd, plcd->power);
128
129 return 0;
130 }
131 #endif
132
133 static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend,
134 platform_lcd_resume);
135
136 #ifdef CONFIG_OF
137 static const struct of_device_id platform_lcd_of_match[] = {
138 { .compatible = "platform-lcd" },
139 {},
140 };
141 MODULE_DEVICE_TABLE(of, platform_lcd_of_match);
142 #endif
143
144 static struct platform_driver platform_lcd_driver = {
145 .driver = {
146 .name = "platform-lcd",
147 .pm = &platform_lcd_pm_ops,
148 .of_match_table = of_match_ptr(platform_lcd_of_match),
149 },
150 .probe = platform_lcd_probe,
151 };
152
153 module_platform_driver(platform_lcd_driver);
154
155 MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
156 MODULE_LICENSE("GPL v2");
157 MODULE_ALIAS("platform:platform-lcd");
158