2 * Generic Syscon LEDs Driver
4 * Copyright (c) 2014, Linaro Limited
5 * Author: Linus Walleij <linus.walleij@linaro.org>
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.
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.
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,
22 * This driver provides system reboot functionality for APM X-Gene SoC.
23 * For system shutdown, this is board specify. If a board designer
24 * implements GPIO shutdown, use the gpio-poweroff.c driver.
27 #include <linux/of_device.h>
28 #include <linux/of_address.h>
29 #include <linux/platform_device.h>
30 #include <linux/stat.h>
31 #include <linux/slab.h>
32 #include <linux/mfd/syscon.h>
33 #include <linux/regmap.h>
34 #include <linux/leds.h>
37 * struct syscon_led - state container for syscon based LEDs
38 * @cdev: LED class device for this LED
39 * @map: regmap to access the syscon device backing this LED
40 * @offset: the offset into the syscon regmap for the LED register
41 * @mask: the bit in the register corresponding to the LED
42 * @state: current state of the LED
45 struct led_classdev cdev
;
52 static void syscon_led_set(struct led_classdev
*led_cdev
,
53 enum led_brightness value
)
55 struct syscon_led
*sled
=
56 container_of(led_cdev
, struct syscon_led
, cdev
);
60 if (value
== LED_OFF
) {
68 ret
= regmap_update_bits(sled
->map
, sled
->offset
, sled
->mask
, val
);
70 dev_err(sled
->cdev
.dev
, "error updating LED status\n");
73 static const struct of_device_id syscon_match
[] = {
74 { .compatible
= "syscon", },
78 static int __init
syscon_leds_init(void)
80 const struct of_device_id
*devid
;
81 struct device_node
*np
;
82 struct device_node
*child
;
84 struct platform_device
*pdev
;
88 np
= of_find_matching_node_and_match(NULL
, syscon_match
,
93 map
= syscon_node_to_regmap(np
);
98 * If the map is there, the device should be there, we allocate
99 * memory on the syscon device's behalf here.
101 pdev
= of_find_device_by_node(np
);
106 for_each_available_child_of_node(np
, child
) {
107 struct syscon_led
*sled
;
110 /* Only check for register-bit-leds */
111 if (of_property_match_string(child
, "compatible",
112 "register-bit-led") < 0)
115 sled
= devm_kzalloc(dev
, sizeof(*sled
), GFP_KERNEL
);
121 if (of_property_read_u32(child
, "offset", &sled
->offset
))
123 if (of_property_read_u32(child
, "mask", &sled
->mask
))
126 of_get_property(child
, "label", NULL
) ? : child
->name
;
127 sled
->cdev
.default_trigger
=
128 of_get_property(child
, "linux,default-trigger", NULL
);
130 state
= of_get_property(child
, "default-state", NULL
);
132 if (!strcmp(state
, "keep")) {
135 ret
= regmap_read(map
, sled
->offset
, &val
);
138 sled
->state
= !!(val
& sled
->mask
);
139 } else if (!strcmp(state
, "on")) {
141 ret
= regmap_update_bits(map
, sled
->offset
,
148 ret
= regmap_update_bits(map
, sled
->offset
,
155 sled
->cdev
.brightness_set
= syscon_led_set
;
157 ret
= led_classdev_register(dev
, &sled
->cdev
);
161 dev_info(dev
, "registered LED %s\n", sled
->cdev
.name
);
166 device_initcall(syscon_leds_init
);