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