linux/drivers/leds/leds-ariel.c
Lubomir Rintel 03f613f057 leds: ariel: Add driver for status LEDs on Dell Wyse 3020
This adds support for controlling the LEDs attached to the Embedded
Controller on a Dell Wyse 3020 "Ariel" board.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
2020-04-27 11:35:11 +02:00

134 lines
3.0 KiB
C

// SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0-or-later
/*
* Dell Wyse 3020 a.k.a. "Ariel" Embedded Controller LED Driver
*
* Copyright (C) 2020 Lubomir Rintel
*/
#include <linux/module.h>
#include <linux/leds.h>
#include <linux/regmap.h>
#include <linux/of_platform.h>
enum ec_index {
EC_BLUE_LED = 0x01,
EC_AMBER_LED = 0x02,
EC_GREEN_LED = 0x03,
};
enum {
EC_LED_OFF = 0x00,
EC_LED_STILL = 0x01,
EC_LED_FADE = 0x02,
EC_LED_BLINK = 0x03,
};
struct ariel_led {
struct regmap *ec_ram;
enum ec_index ec_index;
struct led_classdev led_cdev;
};
#define led_cdev_to_ariel_led(c) container_of(c, struct ariel_led, led_cdev)
static enum led_brightness ariel_led_get(struct led_classdev *led_cdev)
{
struct ariel_led *led = led_cdev_to_ariel_led(led_cdev);
unsigned int led_status = 0;
if (regmap_read(led->ec_ram, led->ec_index, &led_status))
return LED_OFF;
if (led_status == EC_LED_STILL)
return LED_FULL;
else
return LED_OFF;
}
static void ariel_led_set(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
struct ariel_led *led = led_cdev_to_ariel_led(led_cdev);
if (brightness == LED_OFF)
regmap_write(led->ec_ram, led->ec_index, EC_LED_OFF);
else
regmap_write(led->ec_ram, led->ec_index, EC_LED_STILL);
}
static int ariel_blink_set(struct led_classdev *led_cdev,
unsigned long *delay_on, unsigned long *delay_off)
{
struct ariel_led *led = led_cdev_to_ariel_led(led_cdev);
if (*delay_on == 0 && *delay_off == 0)
return -EINVAL;
if (*delay_on == 0) {
regmap_write(led->ec_ram, led->ec_index, EC_LED_OFF);
} else if (*delay_off == 0) {
regmap_write(led->ec_ram, led->ec_index, EC_LED_STILL);
} else {
*delay_on = 500;
*delay_off = 500;
regmap_write(led->ec_ram, led->ec_index, EC_LED_BLINK);
}
return 0;
}
#define NLEDS 3
static int ariel_led_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ariel_led *leds;
struct regmap *ec_ram;
int ret;
int i;
ec_ram = dev_get_regmap(dev->parent, "ec_ram");
if (!ec_ram)
return -ENODEV;
leds = devm_kcalloc(dev, NLEDS, sizeof(*leds), GFP_KERNEL);
if (!leds)
return -ENOMEM;
leds[0].ec_index = EC_BLUE_LED;
leds[0].led_cdev.name = "blue:power",
leds[0].led_cdev.default_trigger = "default-on";
leds[1].ec_index = EC_AMBER_LED;
leds[1].led_cdev.name = "amber:status",
leds[2].ec_index = EC_GREEN_LED;
leds[2].led_cdev.name = "green:status",
leds[2].led_cdev.default_trigger = "default-on";
for (i = 0; i < NLEDS; i++) {
leds[i].ec_ram = ec_ram;
leds[i].led_cdev.brightness_get = ariel_led_get;
leds[i].led_cdev.brightness_set = ariel_led_set;
leds[i].led_cdev.blink_set = ariel_blink_set;
ret = devm_led_classdev_register(dev, &leds[i].led_cdev);
if (ret)
return ret;
}
return 0;
}
static struct platform_driver ariel_led_driver = {
.probe = ariel_led_probe,
.driver = {
.name = "dell-wyse-ariel-led",
},
};
module_platform_driver(ariel_led_driver);
MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
MODULE_DESCRIPTION("Dell Wyse 3020 Status LEDs Driver");
MODULE_LICENSE("Dual BSD/GPL");