Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 | /*
* Generic Syscon LEDs Driver
*
* Copyright (c) 2014, Linaro Limited
* Author: Linus Walleij <linus.walleij@linaro.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
* This driver provides system reboot functionality for APM X-Gene SoC.
* For system shutdown, this is board specify. If a board designer
* implements GPIO shutdown, use the gpio-poweroff.c driver.
*/
#include <linux/io.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/leds.h>
/**
* struct syscon_led - state container for syscon based LEDs
* @cdev: LED class device for this LED
* @map: regmap to access the syscon device backing this LED
* @offset: the offset into the syscon regmap for the LED register
* @mask: the bit in the register corresponding to the LED
* @state: current state of the LED
*/
struct syscon_led {
struct led_classdev cdev;
struct regmap *map;
u32 offset;
u32 mask;
bool state;
};
static void syscon_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct syscon_led *sled =
container_of(led_cdev, struct syscon_led, cdev);
u32 val;
int ret;
if (value == LED_OFF) {
val = 0;
sled->state = false;
} else {
val = sled->mask;
sled->state = true;
}
ret = regmap_update_bits(sled->map, sled->offset, sled->mask, val);
if (ret < 0)
dev_err(sled->cdev.dev, "error updating LED status\n");
}
static const struct of_device_id syscon_match[] = {
{ .compatible = "syscon", },
{},
};
static int __init syscon_leds_init(void)
{
const struct of_device_id *devid;
struct device_node *np;
struct device_node *child;
struct regmap *map;
struct platform_device *pdev;
struct device *dev;
int ret;
np = of_find_matching_node_and_match(NULL, syscon_match,
&devid);
if (!np)
return -ENODEV;
map = syscon_node_to_regmap(np);
if (IS_ERR(map))
return PTR_ERR(map);
/*
* If the map is there, the device should be there, we allocate
* memory on the syscon device's behalf here.
*/
pdev = of_find_device_by_node(np);
if (!pdev)
return -ENODEV;
dev = &pdev->dev;
for_each_available_child_of_node(np, child) {
struct syscon_led *sled;
const char *state;
/* Only check for register-bit-leds */
if (of_property_match_string(child, "compatible",
"register-bit-led") < 0)
continue;
sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL);
if (!sled)
return -ENOMEM;
sled->map = map;
if (of_property_read_u32(child, "offset", &sled->offset))
return -EINVAL;
if (of_property_read_u32(child, "mask", &sled->mask))
return -EINVAL;
sled->cdev.name =
of_get_property(child, "label", NULL) ? : child->name;
sled->cdev.default_trigger =
of_get_property(child, "linux,default-trigger", NULL);
state = of_get_property(child, "default-state", NULL);
if (state) {
if (!strcmp(state, "keep")) {
u32 val;
ret = regmap_read(map, sled->offset, &val);
if (ret < 0)
return ret;
sled->state = !!(val & sled->mask);
} else if (!strcmp(state, "on")) {
sled->state = true;
ret = regmap_update_bits(map, sled->offset,
sled->mask,
sled->mask);
if (ret < 0)
return ret;
} else {
sled->state = false;
ret = regmap_update_bits(map, sled->offset,
sled->mask, 0);
if (ret < 0)
return ret;
}
}
sled->cdev.brightness_set = syscon_led_set;
ret = led_classdev_register(dev, &sled->cdev);
if (ret < 0)
return ret;
dev_info(dev, "registered LED %s\n", sled->cdev.name);
}
return 0;
}
device_initcall(syscon_leds_init);
|