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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * ChromeOS EC LED Driver4 *5 * Copyright (C) 2024 Thomas Weißschuh <linux@weissschuh.net>6 */7 8#include <linux/device.h>9#include <linux/leds.h>10#include <linux/led-class-multicolor.h>11#include <linux/mod_devicetable.h>12#include <linux/module.h>13#include <linux/platform_device.h>14#include <linux/platform_data/cros_ec_commands.h>15#include <linux/platform_data/cros_ec_proto.h>16 17static const char * const cros_ec_led_functions[] = {18 [EC_LED_ID_BATTERY_LED] = LED_FUNCTION_CHARGING,19 [EC_LED_ID_POWER_LED] = LED_FUNCTION_POWER,20 [EC_LED_ID_ADAPTER_LED] = "adapter",21 [EC_LED_ID_LEFT_LED] = "left",22 [EC_LED_ID_RIGHT_LED] = "right",23 [EC_LED_ID_RECOVERY_HW_REINIT_LED] = "recovery-hw-reinit",24 [EC_LED_ID_SYSRQ_DEBUG_LED] = "sysrq-debug",25};26 27static_assert(ARRAY_SIZE(cros_ec_led_functions) == EC_LED_ID_COUNT);28 29static const int cros_ec_led_to_linux_id[] = {30 [EC_LED_COLOR_RED] = LED_COLOR_ID_RED,31 [EC_LED_COLOR_GREEN] = LED_COLOR_ID_GREEN,32 [EC_LED_COLOR_BLUE] = LED_COLOR_ID_BLUE,33 [EC_LED_COLOR_YELLOW] = LED_COLOR_ID_YELLOW,34 [EC_LED_COLOR_WHITE] = LED_COLOR_ID_WHITE,35 [EC_LED_COLOR_AMBER] = LED_COLOR_ID_AMBER,36};37 38static_assert(ARRAY_SIZE(cros_ec_led_to_linux_id) == EC_LED_COLOR_COUNT);39 40static const int cros_ec_linux_to_ec_id[] = {41 [LED_COLOR_ID_RED] = EC_LED_COLOR_RED,42 [LED_COLOR_ID_GREEN] = EC_LED_COLOR_GREEN,43 [LED_COLOR_ID_BLUE] = EC_LED_COLOR_BLUE,44 [LED_COLOR_ID_YELLOW] = EC_LED_COLOR_YELLOW,45 [LED_COLOR_ID_WHITE] = EC_LED_COLOR_WHITE,46 [LED_COLOR_ID_AMBER] = EC_LED_COLOR_AMBER,47};48 49struct cros_ec_led_priv {50 struct led_classdev_mc led_mc_cdev;51 struct cros_ec_device *cros_ec;52 enum ec_led_id led_id;53};54 55static inline struct cros_ec_led_priv *cros_ec_led_cdev_to_priv(struct led_classdev *led_cdev)56{57 return container_of(lcdev_to_mccdev(led_cdev), struct cros_ec_led_priv, led_mc_cdev);58}59 60union cros_ec_led_cmd_data {61 struct ec_params_led_control req;62 struct ec_response_led_control resp;63} __packed;64 65static int cros_ec_led_send_cmd(struct cros_ec_device *cros_ec,66 union cros_ec_led_cmd_data *arg)67{68 int ret;69 struct {70 struct cros_ec_command msg;71 union cros_ec_led_cmd_data data;72 } __packed buf = {73 .msg = {74 .version = 1,75 .command = EC_CMD_LED_CONTROL,76 .insize = sizeof(arg->resp),77 .outsize = sizeof(arg->req),78 },79 .data.req = arg->req80 };81 82 ret = cros_ec_cmd_xfer_status(cros_ec, &buf.msg);83 if (ret < 0)84 return ret;85 86 arg->resp = buf.data.resp;87 88 return 0;89}90 91static int cros_ec_led_trigger_activate(struct led_classdev *led_cdev)92{93 struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev);94 union cros_ec_led_cmd_data arg = {};95 96 arg.req.led_id = priv->led_id;97 arg.req.flags = EC_LED_FLAGS_AUTO;98 99 return cros_ec_led_send_cmd(priv->cros_ec, &arg);100}101 102static struct led_hw_trigger_type cros_ec_led_trigger_type;103 104static struct led_trigger cros_ec_led_trigger = {105 .name = "chromeos-auto",106 .trigger_type = &cros_ec_led_trigger_type,107 .activate = cros_ec_led_trigger_activate,108};109 110static int cros_ec_led_brightness_set_blocking(struct led_classdev *led_cdev,111 enum led_brightness brightness)112{113 struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev);114 union cros_ec_led_cmd_data arg = {};115 enum ec_led_colors led_color;116 struct mc_subled *subled;117 size_t i;118 119 led_mc_calc_color_components(&priv->led_mc_cdev, brightness);120 121 arg.req.led_id = priv->led_id;122 123 for (i = 0; i < priv->led_mc_cdev.num_colors; i++) {124 subled = &priv->led_mc_cdev.subled_info[i];125 led_color = cros_ec_linux_to_ec_id[subled->color_index];126 arg.req.brightness[led_color] = subled->brightness;127 }128 129 return cros_ec_led_send_cmd(priv->cros_ec, &arg);130}131 132static int cros_ec_led_count_subleds(struct device *dev,133 struct ec_response_led_control *resp,134 unsigned int *max_brightness)135{136 unsigned int range, common_range = 0;137 int num_subleds = 0;138 size_t i;139 140 for (i = 0; i < EC_LED_COLOR_COUNT; i++) {141 range = resp->brightness_range[i];142 143 if (!range)144 continue;145 146 num_subleds++;147 148 if (!common_range)149 common_range = range;150 151 if (common_range != range) {152 /* The multicolor LED API expects a uniform max_brightness */153 dev_err(dev, "Inconsistent LED brightness values\n");154 return -EINVAL;155 }156 }157 158 if (!num_subleds)159 return -EINVAL;160 161 *max_brightness = common_range;162 return num_subleds;163}164 165static const char *cros_ec_led_get_color_name(struct led_classdev_mc *led_mc_cdev)166{167 int color;168 169 if (led_mc_cdev->num_colors == 1)170 color = led_mc_cdev->subled_info[0].color_index;171 else172 color = LED_COLOR_ID_MULTI;173 174 return led_get_color_name(color);175}176 177static int cros_ec_led_probe_one(struct device *dev, struct cros_ec_device *cros_ec,178 enum ec_led_id id)179{180 union cros_ec_led_cmd_data arg = {};181 struct cros_ec_led_priv *priv;182 struct led_classdev *led_cdev;183 struct mc_subled *subleds;184 int i, ret, num_subleds;185 size_t subled;186 187 arg.req.led_id = id;188 arg.req.flags = EC_LED_FLAGS_QUERY;189 ret = cros_ec_led_send_cmd(cros_ec, &arg);190 if (ret == -EINVAL)191 return 0; /* Unknown LED, skip */192 if (ret == -EOPNOTSUPP)193 return -ENODEV;194 if (ret < 0)195 return ret;196 197 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);198 if (!priv)199 return -ENOMEM;200 201 num_subleds = cros_ec_led_count_subleds(dev, &arg.resp,202 &priv->led_mc_cdev.led_cdev.max_brightness);203 if (num_subleds < 0)204 return num_subleds;205 206 priv->cros_ec = cros_ec;207 priv->led_id = id;208 209 subleds = devm_kcalloc(dev, num_subleds, sizeof(*subleds), GFP_KERNEL);210 if (!subleds)211 return -ENOMEM;212 213 subled = 0;214 for (i = 0; i < EC_LED_COLOR_COUNT; i++) {215 if (!arg.resp.brightness_range[i])216 continue;217 218 subleds[subled].color_index = cros_ec_led_to_linux_id[i];219 if (subled == 0)220 subleds[subled].intensity = 100;221 subled++;222 }223 224 priv->led_mc_cdev.subled_info = subleds;225 priv->led_mc_cdev.num_colors = num_subleds;226 227 led_cdev = &priv->led_mc_cdev.led_cdev;228 led_cdev->brightness_set_blocking = cros_ec_led_brightness_set_blocking;229 led_cdev->trigger_type = &cros_ec_led_trigger_type;230 led_cdev->default_trigger = cros_ec_led_trigger.name;231 led_cdev->hw_control_trigger = cros_ec_led_trigger.name;232 233 led_cdev->name = devm_kasprintf(dev, GFP_KERNEL, "chromeos:%s:%s",234 cros_ec_led_get_color_name(&priv->led_mc_cdev),235 cros_ec_led_functions[id]);236 if (!led_cdev->name)237 return -ENOMEM;238 239 return devm_led_classdev_multicolor_register(dev, &priv->led_mc_cdev);240}241 242static int cros_ec_led_probe(struct platform_device *pdev)243{244 struct device *dev = &pdev->dev;245 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);246 struct cros_ec_device *cros_ec = ec_dev->ec_dev;247 int i, ret = 0;248 249 ret = devm_led_trigger_register(dev, &cros_ec_led_trigger);250 if (ret)251 return ret;252 253 for (i = 0; i < EC_LED_ID_COUNT; i++) {254 ret = cros_ec_led_probe_one(dev, cros_ec, i);255 if (ret)256 break;257 }258 259 return ret;260}261 262static const struct platform_device_id cros_ec_led_id[] = {263 { "cros-ec-led", 0 },264 {}265};266 267static struct platform_driver cros_ec_led_driver = {268 .driver.name = "cros-ec-led",269 .probe = cros_ec_led_probe,270 .id_table = cros_ec_led_id,271};272module_platform_driver(cros_ec_led_driver);273 274MODULE_DEVICE_TABLE(platform, cros_ec_led_id);275MODULE_DESCRIPTION("ChromeOS EC LED Driver");276MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net");277MODULE_LICENSE("GPL");278