1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * ChromeOS EC LED Driver 4 * 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 17 static 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 27 static_assert(ARRAY_SIZE(cros_ec_led_functions) == EC_LED_ID_COUNT); 28 29 static 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 38 static_assert(ARRAY_SIZE(cros_ec_led_to_linux_id) == EC_LED_COLOR_COUNT); 39 40 static 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 49 struct 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 55 static 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 60 union cros_ec_led_cmd_data { 61 struct ec_params_led_control req; 62 struct ec_response_led_control resp; 63 } __packed; 64 65 static 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->req 80 }; 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 91 static 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 } 101 102 static struct led_hw_trigger_type cros_ec_led_trigger_type; 103 104 static 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 }; 109 110 static 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 } 131 132 static 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 } 164 165 static 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 else 172 color = LED_COLOR_ID_MULTI; 173 174 return led_get_color_name(color); 175 } 176 177 static 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 } 241 242 static 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 } 261 262 static const struct platform_device_id cros_ec_led_id[] = { 263 { "cros-ec-led", 0 }, 264 {} 265 }; 266 267 static 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 }; 272 module_platform_driver(cros_ec_led_driver); 273 274 MODULE_DEVICE_TABLE(platform, cros_ec_led_id); 275 MODULE_DESCRIPTION("ChromeOS EC LED Driver"); 276 MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net"); 277 MODULE_LICENSE("GPL"); 278