// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ChromeOS EC LED Driver
*
* Copyright (C) 2024 Thomas Weißschuh <[email protected]>
*/
#include <linux/device.h>
#include <linux/leds.h>
#include <linux/led-class-multicolor.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
static const char * const cros_ec_led_functions[] = {
[EC_LED_ID_BATTERY_LED] = LED_FUNCTION_CHARGING,
[EC_LED_ID_POWER_LED] = LED_FUNCTION_POWER,
[EC_LED_ID_ADAPTER_LED] = "adapter",
[EC_LED_ID_LEFT_LED] = "left",
[EC_LED_ID_RIGHT_LED] = "right",
[EC_LED_ID_RECOVERY_HW_REINIT_LED] = "recovery-hw-reinit",
[EC_LED_ID_SYSRQ_DEBUG_LED] = "sysrq-debug",
};
static_assert(ARRAY_SIZE(cros_ec_led_functions) == EC_LED_ID_COUNT);
static const int cros_ec_led_to_linux_id[] = {
[EC_LED_COLOR_RED] = LED_COLOR_ID_RED,
[EC_LED_COLOR_GREEN] = LED_COLOR_ID_GREEN,
[EC_LED_COLOR_BLUE] = LED_COLOR_ID_BLUE,
[EC_LED_COLOR_YELLOW] = LED_COLOR_ID_YELLOW,
[EC_LED_COLOR_WHITE] = LED_COLOR_ID_WHITE,
[EC_LED_COLOR_AMBER] = LED_COLOR_ID_AMBER,
};
static_assert(ARRAY_SIZE(cros_ec_led_to_linux_id) == EC_LED_COLOR_COUNT);
static const int cros_ec_linux_to_ec_id[] = {
[LED_COLOR_ID_RED] = EC_LED_COLOR_RED,
[LED_COLOR_ID_GREEN] = EC_LED_COLOR_GREEN,
[LED_COLOR_ID_BLUE] = EC_LED_COLOR_BLUE,
[LED_COLOR_ID_YELLOW] = EC_LED_COLOR_YELLOW,
[LED_COLOR_ID_WHITE] = EC_LED_COLOR_WHITE,
[LED_COLOR_ID_AMBER] = EC_LED_COLOR_AMBER,
};
struct cros_ec_led_priv {
struct led_classdev_mc led_mc_cdev;
struct cros_ec_device *cros_ec;
enum ec_led_id led_id;
};
static inline struct cros_ec_led_priv *cros_ec_led_cdev_to_priv(struct led_classdev *led_cdev)
{
return container_of(lcdev_to_mccdev(led_cdev), struct cros_ec_led_priv, led_mc_cdev);
}
union cros_ec_led_cmd_data {
struct ec_params_led_control req;
struct ec_response_led_control resp;
} __packed;
static int cros_ec_led_send_cmd(struct cros_ec_device *cros_ec,
union cros_ec_led_cmd_data *arg)
{
int ret;
struct {
struct cros_ec_command msg;
union cros_ec_led_cmd_data data;
} __packed buf = {
.msg = {
.version = 1,
.command = EC_CMD_LED_CONTROL,
.insize = sizeof(arg->resp),
.outsize = sizeof(arg->req),
},
.data.req = arg->req
};
ret = cros_ec_cmd_xfer_status(cros_ec, &buf.msg);
if (ret < 0)
return ret;
arg->resp = buf.data.resp;
return 0;
}
static int cros_ec_led_trigger_activate(struct led_classdev *led_cdev)
{
struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev);
union cros_ec_led_cmd_data arg = {};
arg.req.led_id = priv->led_id;
arg.req.flags = EC_LED_FLAGS_AUTO;
return cros_ec_led_send_cmd(priv->cros_ec, &arg);
}
static struct led_hw_trigger_type cros_ec_led_trigger_type;
static struct led_trigger cros_ec_led_trigger = {
.name = "chromeos-auto",
.trigger_type = &cros_ec_led_trigger_type,
.activate = cros_ec_led_trigger_activate,
};
static int cros_ec_led_brightness_set_blocking(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev);
union cros_ec_led_cmd_data arg = {};
enum ec_led_colors led_color;
struct mc_subled *subled;
size_t i;
led_mc_calc_color_components(&priv->led_mc_cdev, brightness);
arg.req.led_id = priv->led_id;
for (i = 0; i < priv->led_mc_cdev.num_colors; i++) {
subled = &priv->led_mc_cdev.subled_info[i];
led_color = cros_ec_linux_to_ec_id[subled->color_index];
arg.req.brightness[led_color] = subled->brightness;
}
return cros_ec_led_send_cmd(priv->cros_ec, &arg);
}
static int cros_ec_led_count_subleds(struct device *dev,
struct ec_response_led_control *resp,
unsigned int *max_brightness)
{
unsigned int range, common_range = 0;
int num_subleds = 0;
size_t i;
for (i = 0; i < EC_LED_COLOR_COUNT; i++) {
range = resp->brightness_range[i];
if (!range)
continue;
num_subleds++;
if (!common_range)
common_range = range;
if (common_range != range) {
/* The multicolor LED API expects a uniform max_brightness */
dev_err(dev, "Inconsistent LED brightness values\n");
return -EINVAL;
}
}
if (!num_subleds)
return -EINVAL;
*max_brightness = common_range;
return num_subleds;
}
static const char *cros_ec_led_get_color_name(struct led_classdev_mc *led_mc_cdev)
{
int color;
if (led_mc_cdev->num_colors == 1)
color = led_mc_cdev->subled_info[0].color_index;
else
color = LED_COLOR_ID_MULTI;
return led_get_color_name(color);
}
static int cros_ec_led_probe_one(struct device *dev, struct cros_ec_device *cros_ec,
enum ec_led_id id)
{
union cros_ec_led_cmd_data arg = {};
struct cros_ec_led_priv *priv;
struct led_classdev *led_cdev;
struct mc_subled *subleds;
int i, ret, num_subleds;
size_t subled;
arg.req.led_id = id;
arg.req.flags = EC_LED_FLAGS_QUERY;
ret = cros_ec_led_send_cmd(cros_ec, &arg);
if (ret == -EINVAL)
return 0; /* Unknown LED, skip */
if (ret == -EOPNOTSUPP)
return -ENODEV;
if (ret < 0)
return ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
num_subleds = cros_ec_led_count_subleds(dev, &arg.resp,
&priv->led_mc_cdev.led_cdev.max_brightness);
if (num_subleds < 0)
return num_subleds;
priv->cros_ec = cros_ec;
priv->led_id = id;
subleds = devm_kcalloc(dev, num_subleds, sizeof(*subleds), GFP_KERNEL);
if (!subleds)
return -ENOMEM;
subled = 0;
for (i = 0; i < EC_LED_COLOR_COUNT; i++) {
if (!arg.resp.brightness_range[i])
continue;
subleds[subled].color_index = cros_ec_led_to_linux_id[i];
if (subled == 0)
subleds[subled].intensity = 100;
subled++;
}
priv->led_mc_cdev.subled_info = subleds;
priv->led_mc_cdev.num_colors = num_subleds;
led_cdev = &priv->led_mc_cdev.led_cdev;
led_cdev->brightness_set_blocking = cros_ec_led_brightness_set_blocking;
led_cdev->trigger_type = &cros_ec_led_trigger_type;
led_cdev->default_trigger = cros_ec_led_trigger.name;
led_cdev->hw_control_trigger = cros_ec_led_trigger.name;
led_cdev->name = devm_kasprintf(dev, GFP_KERNEL, "chromeos:%s:%s",
cros_ec_led_get_color_name(&priv->led_mc_cdev),
cros_ec_led_functions[id]);
if (!led_cdev->name)
return -ENOMEM;
return devm_led_classdev_multicolor_register(dev, &priv->led_mc_cdev);
}
static int cros_ec_led_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
struct cros_ec_device *cros_ec = ec_dev->ec_dev;
int i, ret = 0;
ret = devm_led_trigger_register(dev, &cros_ec_led_trigger);
if (ret)
return ret;
for (i = 0; i < EC_LED_ID_COUNT; i++) {
ret = cros_ec_led_probe_one(dev, cros_ec, i);
if (ret)
break;
}
return ret;
}
static const struct platform_device_id cros_ec_led_id[] = {
{ "cros-ec-led", 0 },
{}
};
static struct platform_driver cros_ec_led_driver = {
.driver.name = "cros-ec-led",
.probe = cros_ec_led_probe,
.id_table = cros_ec_led_id,
};
module_platform_driver(cros_ec_led_driver);
MODULE_DEVICE_TABLE(platform, cros_ec_led_id);
MODULE_DESCRIPTION("ChromeOS EC LED Driver");
MODULE_AUTHOR("Thomas Weißschuh <[email protected]");
MODULE_LICENSE("GPL");
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