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> |
535f09cc LW |
10 | #include <linux/of_device.h> |
11 | #include <linux/of_address.h> | |
12 | #include <linux/platform_device.h> | |
13 | #include <linux/stat.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/mfd/syscon.h> | |
16 | #include <linux/regmap.h> | |
17 | #include <linux/leds.h> | |
18 | ||
19 | /** | |
20 | * struct syscon_led - state container for syscon based LEDs | |
21 | * @cdev: LED class device for this LED | |
22 | * @map: regmap to access the syscon device backing this LED | |
23 | * @offset: the offset into the syscon regmap for the LED register | |
24 | * @mask: the bit in the register corresponding to the LED | |
25 | * @state: current state of the LED | |
26 | */ | |
27 | struct syscon_led { | |
28 | struct led_classdev cdev; | |
29 | struct regmap *map; | |
30 | u32 offset; | |
31 | u32 mask; | |
32 | bool state; | |
33 | }; | |
34 | ||
35 | static void syscon_led_set(struct led_classdev *led_cdev, | |
36 | enum led_brightness value) | |
37 | { | |
38 | struct syscon_led *sled = | |
39 | container_of(led_cdev, struct syscon_led, cdev); | |
40 | u32 val; | |
41 | int ret; | |
42 | ||
43 | if (value == LED_OFF) { | |
44 | val = 0; | |
45 | sled->state = false; | |
46 | } else { | |
47 | val = sled->mask; | |
48 | sled->state = true; | |
49 | } | |
50 | ||
51 | ret = regmap_update_bits(sled->map, sled->offset, sled->mask, val); | |
52 | if (ret < 0) | |
53 | dev_err(sled->cdev.dev, "error updating LED status\n"); | |
54 | } | |
55 | ||
a917d4b4 | 56 | static int syscon_led_probe(struct platform_device *pdev) |
535f09cc | 57 | { |
00663196 | 58 | struct led_init_data init_data = {}; |
a917d4b4 | 59 | struct device *dev = &pdev->dev; |
8853c95e | 60 | struct device_node *np = dev_of_node(dev); |
a917d4b4 LW |
61 | struct device *parent; |
62 | struct regmap *map; | |
63 | struct syscon_led *sled; | |
265d313e AS |
64 | enum led_default_state state; |
65 | u32 value; | |
535f09cc LW |
66 | int ret; |
67 | ||
a917d4b4 LW |
68 | parent = dev->parent; |
69 | if (!parent) { | |
70 | dev_err(dev, "no parent for syscon LED\n"); | |
71 | return -ENODEV; | |
72 | } | |
8853c95e | 73 | map = syscon_node_to_regmap(dev_of_node(parent)); |
991a3f61 | 74 | if (IS_ERR(map)) { |
a917d4b4 | 75 | dev_err(dev, "no regmap for syscon LED parent\n"); |
991a3f61 | 76 | return PTR_ERR(map); |
a917d4b4 LW |
77 | } |
78 | ||
79 | sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL); | |
80 | if (!sled) | |
81 | return -ENOMEM; | |
82 | ||
83 | sled->map = map; | |
84 | ||
85 | if (of_property_read_u32(np, "offset", &sled->offset)) | |
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); |