1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0+
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun /*
4*4882a593Smuzhiyun * LCD Backlight driver for RAVE SP
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * Copyright (C) 2018 Zodiac Inflight Innovations
7*4882a593Smuzhiyun *
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/backlight.h>
11*4882a593Smuzhiyun #include <linux/kernel.h>
12*4882a593Smuzhiyun #include <linux/module.h>
13*4882a593Smuzhiyun #include <linux/mfd/rave-sp.h>
14*4882a593Smuzhiyun #include <linux/platform_device.h>
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun #define RAVE_SP_BACKLIGHT_LCD_EN BIT(7)
17*4882a593Smuzhiyun
rave_sp_backlight_update_status(struct backlight_device * bd)18*4882a593Smuzhiyun static int rave_sp_backlight_update_status(struct backlight_device *bd)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun const struct backlight_properties *p = &bd->props;
21*4882a593Smuzhiyun const u8 intensity =
22*4882a593Smuzhiyun (p->power == FB_BLANK_UNBLANK) ? p->brightness : 0;
23*4882a593Smuzhiyun struct rave_sp *sp = dev_get_drvdata(&bd->dev);
24*4882a593Smuzhiyun u8 cmd[] = {
25*4882a593Smuzhiyun [0] = RAVE_SP_CMD_SET_BACKLIGHT,
26*4882a593Smuzhiyun [1] = 0,
27*4882a593Smuzhiyun [2] = intensity ? RAVE_SP_BACKLIGHT_LCD_EN | intensity : 0,
28*4882a593Smuzhiyun [3] = 0,
29*4882a593Smuzhiyun [4] = 0,
30*4882a593Smuzhiyun };
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun return rave_sp_exec(sp, cmd, sizeof(cmd), NULL, 0);
33*4882a593Smuzhiyun }
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun static const struct backlight_ops rave_sp_backlight_ops = {
36*4882a593Smuzhiyun .options = BL_CORE_SUSPENDRESUME,
37*4882a593Smuzhiyun .update_status = rave_sp_backlight_update_status,
38*4882a593Smuzhiyun };
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun static struct backlight_properties rave_sp_backlight_props = {
41*4882a593Smuzhiyun .type = BACKLIGHT_PLATFORM,
42*4882a593Smuzhiyun .max_brightness = 100,
43*4882a593Smuzhiyun .brightness = 50,
44*4882a593Smuzhiyun };
45*4882a593Smuzhiyun
rave_sp_backlight_probe(struct platform_device * pdev)46*4882a593Smuzhiyun static int rave_sp_backlight_probe(struct platform_device *pdev)
47*4882a593Smuzhiyun {
48*4882a593Smuzhiyun struct device *dev = &pdev->dev;
49*4882a593Smuzhiyun struct backlight_device *bd;
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun bd = devm_backlight_device_register(dev, pdev->name, dev,
52*4882a593Smuzhiyun dev_get_drvdata(dev->parent),
53*4882a593Smuzhiyun &rave_sp_backlight_ops,
54*4882a593Smuzhiyun &rave_sp_backlight_props);
55*4882a593Smuzhiyun if (IS_ERR(bd))
56*4882a593Smuzhiyun return PTR_ERR(bd);
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun /*
59*4882a593Smuzhiyun * If there is a phandle pointing to the device node we can
60*4882a593Smuzhiyun * assume that another device will manage the status changes.
61*4882a593Smuzhiyun * If not we make sure the backlight is in a consistent state.
62*4882a593Smuzhiyun */
63*4882a593Smuzhiyun if (!dev->of_node->phandle)
64*4882a593Smuzhiyun backlight_update_status(bd);
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun return 0;
67*4882a593Smuzhiyun }
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun static const struct of_device_id rave_sp_backlight_of_match[] = {
70*4882a593Smuzhiyun { .compatible = "zii,rave-sp-backlight" },
71*4882a593Smuzhiyun {}
72*4882a593Smuzhiyun };
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun static struct platform_driver rave_sp_backlight_driver = {
75*4882a593Smuzhiyun .probe = rave_sp_backlight_probe,
76*4882a593Smuzhiyun .driver = {
77*4882a593Smuzhiyun .name = KBUILD_MODNAME,
78*4882a593Smuzhiyun .of_match_table = rave_sp_backlight_of_match,
79*4882a593Smuzhiyun },
80*4882a593Smuzhiyun };
81*4882a593Smuzhiyun module_platform_driver(rave_sp_backlight_driver);
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun MODULE_DEVICE_TABLE(of, rave_sp_backlight_of_match);
84*4882a593Smuzhiyun MODULE_LICENSE("GPL");
85*4882a593Smuzhiyun MODULE_AUTHOR("Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>");
86*4882a593Smuzhiyun MODULE_AUTHOR("Nikita Yushchenko <nikita.yoush@cogentembedded.com>");
87*4882a593Smuzhiyun MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>");
88*4882a593Smuzhiyun MODULE_DESCRIPTION("RAVE SP Backlight driver");
89