Commit | Line | Data |
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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
535f09cc LW |
2 | /* |
3 | * Generic Syscon LEDs Driver | |
4 | * | |
5 | * Copyright (c) 2014, Linaro Limited | |
6 | * Author: Linus Walleij <linus.walleij@linaro.org> | |
535f09cc LW |
7 | */ |
8 | #include <linux/io.h> | |
f7d98a65 | 9 | #include <linux/init.h> |
3192f141 | 10 | #include <linux/of.h> |
535f09cc LW |
11 | #include <linux/platform_device.h> |
12 | #include <linux/stat.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/mfd/syscon.h> | |
15 | #include <linux/regmap.h> | |
16 | #include <linux/leds.h> | |
17 | ||
18 | /** | |
19 | * struct syscon_led - state container for syscon based LEDs | |
20 | * @cdev: LED class device for this LED | |
21 | * @map: regmap to access the syscon device backing this LED | |
22 | * @offset: the offset into the syscon regmap for the LED register | |
23 | * @mask: the bit in the register corresponding to the LED | |
24 | * @state: current state of the LED | |
25 | */ | |
26 | struct syscon_led { | |
27 | struct led_classdev cdev; | |
28 | struct regmap *map; | |
29 | u32 offset; | |
30 | u32 mask; | |
31 | bool state; | |
32 | }; | |
33 | ||
34 | static void syscon_led_set(struct led_classdev *led_cdev, | |
35 | enum led_brightness value) | |
36 | { | |
37 | struct syscon_led *sled = | |
38 | container_of(led_cdev, struct syscon_led, cdev); | |
39 | u32 val; | |
40 | int ret; | |
41 | ||
42 | if (value == LED_OFF) { | |
43 | val = 0; | |
44 | sled->state = false; | |
45 | } else { | |
46 | val = sled->mask; | |
47 | sled->state = true; | |
48 | } | |
49 | ||
50 | ret = regmap_update_bits(sled->map, sled->offset, sled->mask, val); | |
51 | if (ret < 0) | |
52 | dev_err(sled->cdev.dev, "error updating LED status\n"); | |
53 | } | |
54 | ||
a917d4b4 | 55 | static int syscon_led_probe(struct platform_device *pdev) |
535f09cc | 56 | { |
00663196 | 57 | struct led_init_data init_data = {}; |
a917d4b4 | 58 | struct device *dev = &pdev->dev; |
8853c95e | 59 | struct device_node *np = dev_of_node(dev); |
a917d4b4 LW |
60 | struct device *parent; |
61 | struct regmap *map; | |
62 | struct syscon_led *sled; | |
265d313e AS |
63 | enum led_default_state state; |
64 | u32 value; | |
535f09cc LW |
65 | int ret; |
66 | ||
a917d4b4 LW |
67 | parent = dev->parent; |
68 | if (!parent) { | |
69 | dev_err(dev, "no parent for syscon LED\n"); | |
70 | return -ENODEV; | |
71 | } | |
8853c95e | 72 | map = syscon_node_to_regmap(dev_of_node(parent)); |
991a3f61 | 73 | if (IS_ERR(map)) { |
a917d4b4 | 74 | dev_err(dev, "no regmap for syscon LED parent\n"); |
991a3f61 | 75 | return PTR_ERR(map); |
a917d4b4 LW |
76 | } |
77 | ||
78 | sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL); | |
79 | if (!sled) | |
80 | return -ENOMEM; | |
81 | ||
82 | sled->map = map; | |
83 | ||
a82cc9b8 RH |
84 | if (of_property_read_u32(np, "reg", &sled->offset) && |
85 | of_property_read_u32(np, "offset", &sled->offset)) | |
a917d4b4 LW |
86 | return -EINVAL; |
87 | if (of_property_read_u32(np, "mask", &sled->mask)) | |
88 | return -EINVAL; | |
a917d4b4 | 89 | |
265d313e AS |
90 | init_data.fwnode = of_fwnode_handle(np); |
91 | ||
92 | state = led_init_default_state_get(init_data.fwnode); | |
93 | switch (state) { | |
94 | case LEDS_DEFSTATE_ON: | |
95 | ret = regmap_update_bits(map, sled->offset, sled->mask, sled->mask); | |
96 | if (ret < 0) | |
97 | return ret; | |
98 | sled->state = true; | |
99 | break; | |
100 | case LEDS_DEFSTATE_KEEP: | |
101 | ret = regmap_read(map, sled->offset, &value); | |
102 | if (ret < 0) | |
103 | return ret; | |
104 | sled->state = !!(value & sled->mask); | |
105 | break; | |
106 | default: | |
107 | ret = regmap_update_bits(map, sled->offset, sled->mask, 0); | |
108 | if (ret < 0) | |
109 | return ret; | |
110 | sled->state = false; | |
a917d4b4 LW |
111 | } |
112 | sled->cdev.brightness_set = syscon_led_set; | |
535f09cc | 113 | |
00663196 | 114 | ret = devm_led_classdev_register_ext(dev, &sled->cdev, &init_data); |
a917d4b4 LW |
115 | if (ret < 0) |
116 | return ret; | |
117 | ||
118 | platform_set_drvdata(pdev, sled); | |
119 | dev_info(dev, "registered LED %s\n", sled->cdev.name); | |
535f09cc | 120 | |
3f6e42c8 LW |
121 | return 0; |
122 | } | |
123 | ||
a917d4b4 LW |
124 | static const struct of_device_id of_syscon_leds_match[] = { |
125 | { .compatible = "register-bit-led", }, | |
126 | {}, | |
127 | }; | |
3f6e42c8 | 128 | |
a917d4b4 LW |
129 | static struct platform_driver syscon_led_driver = { |
130 | .probe = syscon_led_probe, | |
a917d4b4 LW |
131 | .driver = { |
132 | .name = "leds-syscon", | |
133 | .of_match_table = of_syscon_leds_match, | |
f7d98a65 | 134 | .suppress_bind_attrs = true, |
a917d4b4 LW |
135 | }, |
136 | }; | |
f7d98a65 | 137 | builtin_platform_driver(syscon_led_driver); |