138 lines
3.2 KiB
C
138 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Generic Syscon LEDs Driver
|
|
*
|
|
* Copyright (c) 2014, Linaro Limited
|
|
* Author: Linus Walleij <linus.walleij@linaro.org>
|
|
*/
|
|
#include <linux/io.h>
|
|
#include <linux/init.h>
|
|
#include <linux/of.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 int syscon_led_probe(struct platform_device *pdev)
|
|
{
|
|
struct led_init_data init_data = {};
|
|
struct device *dev = &pdev->dev;
|
|
struct device_node *np = dev_of_node(dev);
|
|
struct device *parent;
|
|
struct regmap *map;
|
|
struct syscon_led *sled;
|
|
enum led_default_state state;
|
|
u32 value;
|
|
int ret;
|
|
|
|
parent = dev->parent;
|
|
if (!parent) {
|
|
dev_err(dev, "no parent for syscon LED\n");
|
|
return -ENODEV;
|
|
}
|
|
map = syscon_node_to_regmap(dev_of_node(parent));
|
|
if (IS_ERR(map)) {
|
|
dev_err(dev, "no regmap for syscon LED parent\n");
|
|
return PTR_ERR(map);
|
|
}
|
|
|
|
sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL);
|
|
if (!sled)
|
|
return -ENOMEM;
|
|
|
|
sled->map = map;
|
|
|
|
if (of_property_read_u32(np, "reg", &sled->offset) &&
|
|
of_property_read_u32(np, "offset", &sled->offset))
|
|
return -EINVAL;
|
|
if (of_property_read_u32(np, "mask", &sled->mask))
|
|
return -EINVAL;
|
|
|
|
init_data.fwnode = of_fwnode_handle(np);
|
|
|
|
state = led_init_default_state_get(init_data.fwnode);
|
|
switch (state) {
|
|
case LEDS_DEFSTATE_ON:
|
|
ret = regmap_update_bits(map, sled->offset, sled->mask, sled->mask);
|
|
if (ret < 0)
|
|
return ret;
|
|
sled->state = true;
|
|
break;
|
|
case LEDS_DEFSTATE_KEEP:
|
|
ret = regmap_read(map, sled->offset, &value);
|
|
if (ret < 0)
|
|
return ret;
|
|
sled->state = !!(value & sled->mask);
|
|
break;
|
|
default:
|
|
ret = regmap_update_bits(map, sled->offset, sled->mask, 0);
|
|
if (ret < 0)
|
|
return ret;
|
|
sled->state = false;
|
|
}
|
|
sled->cdev.brightness_set = syscon_led_set;
|
|
|
|
ret = devm_led_classdev_register_ext(dev, &sled->cdev, &init_data);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
platform_set_drvdata(pdev, sled);
|
|
dev_info(dev, "registered LED %s\n", sled->cdev.name);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id of_syscon_leds_match[] = {
|
|
{ .compatible = "register-bit-led", },
|
|
{},
|
|
};
|
|
|
|
static struct platform_driver syscon_led_driver = {
|
|
.probe = syscon_led_probe,
|
|
.driver = {
|
|
.name = "leds-syscon",
|
|
.of_match_table = of_syscon_leds_match,
|
|
.suppress_bind_attrs = true,
|
|
},
|
|
};
|
|
builtin_platform_driver(syscon_led_driver);
|