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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Generic Syscon LEDs Driver
4 *
5 * Copyright (c) 2014, Linaro Limited
6 * Author: Linus Walleij <linus.walleij@linaro.org>
7 */
8#include <linux/io.h>
9#include <linux/init.h>
10#include <linux/of.h>
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 */
26struct syscon_led {
27 struct led_classdev cdev;
28 struct regmap *map;
29 u32 offset;
30 u32 mask;
31 bool state;
32};
33
34static 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
55static int syscon_led_probe(struct platform_device *pdev)
56{
57 struct led_init_data init_data = {};
58 struct device *dev = &pdev->dev;
59 struct device_node *np = dev_of_node(dev);
60 struct device *parent;
61 struct regmap *map;
62 struct syscon_led *sled;
63 enum led_default_state state;
64 u32 value;
65 int ret;
66
67 parent = dev->parent;
68 if (!parent) {
69 dev_err(dev, "no parent for syscon LED\n");
70 return -ENODEV;
71 }
72 map = syscon_node_to_regmap(dev_of_node(parent));
73 if (IS_ERR(map)) {
74 dev_err(dev, "no regmap for syscon LED parent\n");
75 return PTR_ERR(map);
76 }
77
78 sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL);
79 if (!sled)
80 return -ENOMEM;
81
82 sled->map = map;
83
84 if (of_property_read_u32(np, "reg", &sled->offset) &&
85 of_property_read_u32(np, "offset", &sled->offset))
86 return -EINVAL;
87 if (of_property_read_u32(np, "mask", &sled->mask))
88 return -EINVAL;
89
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;
111 }
112 sled->cdev.brightness_set = syscon_led_set;
113
114 ret = devm_led_classdev_register_ext(dev, &sled->cdev, &init_data);
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);
120
121 return 0;
122}
123
124static const struct of_device_id of_syscon_leds_match[] = {
125 { .compatible = "register-bit-led", },
126 {},
127};
128
129static struct platform_driver syscon_led_driver = {
130 .probe = syscon_led_probe,
131 .driver = {
132 .name = "leds-syscon",
133 .of_match_table = of_syscon_leds_match,
134 .suppress_bind_attrs = true,
135 },
136};
137builtin_platform_driver(syscon_led_driver);
1/*
2 * Generic Syscon LEDs Driver
3 *
4 * Copyright (c) 2014, Linaro Limited
5 * Author: Linus Walleij <linus.walleij@linaro.org>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
20 * MA 02111-1307 USA
21 */
22#include <linux/io.h>
23#include <linux/init.h>
24#include <linux/of_device.h>
25#include <linux/of_address.h>
26#include <linux/platform_device.h>
27#include <linux/stat.h>
28#include <linux/slab.h>
29#include <linux/mfd/syscon.h>
30#include <linux/regmap.h>
31#include <linux/leds.h>
32
33/**
34 * struct syscon_led - state container for syscon based LEDs
35 * @cdev: LED class device for this LED
36 * @map: regmap to access the syscon device backing this LED
37 * @offset: the offset into the syscon regmap for the LED register
38 * @mask: the bit in the register corresponding to the LED
39 * @state: current state of the LED
40 */
41struct syscon_led {
42 struct led_classdev cdev;
43 struct regmap *map;
44 u32 offset;
45 u32 mask;
46 bool state;
47};
48
49static void syscon_led_set(struct led_classdev *led_cdev,
50 enum led_brightness value)
51{
52 struct syscon_led *sled =
53 container_of(led_cdev, struct syscon_led, cdev);
54 u32 val;
55 int ret;
56
57 if (value == LED_OFF) {
58 val = 0;
59 sled->state = false;
60 } else {
61 val = sled->mask;
62 sled->state = true;
63 }
64
65 ret = regmap_update_bits(sled->map, sled->offset, sled->mask, val);
66 if (ret < 0)
67 dev_err(sled->cdev.dev, "error updating LED status\n");
68}
69
70static int syscon_led_probe(struct platform_device *pdev)
71{
72 struct device *dev = &pdev->dev;
73 struct device_node *np = dev->of_node;
74 struct device *parent;
75 struct regmap *map;
76 struct syscon_led *sled;
77 const char *state;
78 int ret;
79
80 parent = dev->parent;
81 if (!parent) {
82 dev_err(dev, "no parent for syscon LED\n");
83 return -ENODEV;
84 }
85 map = syscon_node_to_regmap(parent->of_node);
86 if (IS_ERR(map)) {
87 dev_err(dev, "no regmap for syscon LED parent\n");
88 return PTR_ERR(map);
89 }
90
91 sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL);
92 if (!sled)
93 return -ENOMEM;
94
95 sled->map = map;
96
97 if (of_property_read_u32(np, "offset", &sled->offset))
98 return -EINVAL;
99 if (of_property_read_u32(np, "mask", &sled->mask))
100 return -EINVAL;
101 sled->cdev.name =
102 of_get_property(np, "label", NULL) ? : np->name;
103 sled->cdev.default_trigger =
104 of_get_property(np, "linux,default-trigger", NULL);
105
106 state = of_get_property(np, "default-state", NULL);
107 if (state) {
108 if (!strcmp(state, "keep")) {
109 u32 val;
110
111 ret = regmap_read(map, sled->offset, &val);
112 if (ret < 0)
113 return ret;
114 sled->state = !!(val & sled->mask);
115 } else if (!strcmp(state, "on")) {
116 sled->state = true;
117 ret = regmap_update_bits(map, sled->offset,
118 sled->mask,
119 sled->mask);
120 if (ret < 0)
121 return ret;
122 } else {
123 sled->state = false;
124 ret = regmap_update_bits(map, sled->offset,
125 sled->mask, 0);
126 if (ret < 0)
127 return ret;
128 }
129 }
130 sled->cdev.brightness_set = syscon_led_set;
131
132 ret = led_classdev_register(dev, &sled->cdev);
133 if (ret < 0)
134 return ret;
135
136 platform_set_drvdata(pdev, sled);
137 dev_info(dev, "registered LED %s\n", sled->cdev.name);
138
139 return 0;
140}
141
142static const struct of_device_id of_syscon_leds_match[] = {
143 { .compatible = "register-bit-led", },
144 {},
145};
146
147static struct platform_driver syscon_led_driver = {
148 .probe = syscon_led_probe,
149 .driver = {
150 .name = "leds-syscon",
151 .of_match_table = of_syscon_leds_match,
152 .suppress_bind_attrs = true,
153 },
154};
155builtin_platform_driver(syscon_led_driver);