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 }; 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 70 ret = cros_ec_cmd(cros_ec, 1, EC_CMD_LED_CONTROL, &arg->req, 71 sizeof(arg->req), &arg->resp, sizeof(arg->resp)); 72 if (ret < 0) 73 return ret; 74 75 return 0; 76 } 77 78 static int cros_ec_led_trigger_activate(struct led_classdev *led_cdev) 79 { 80 struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev); 81 union cros_ec_led_cmd_data arg = {}; 82 83 arg.req.led_id = priv->led_id; 84 arg.req.flags = EC_LED_FLAGS_AUTO; 85 86 return cros_ec_led_send_cmd(priv->cros_ec, &arg); 87 } 88 89 static struct led_hw_trigger_type cros_ec_led_trigger_type; 90 91 static struct led_trigger cros_ec_led_trigger = { 92 .name = "chromeos-auto", 93 .trigger_type = &cros_ec_led_trigger_type, 94 .activate = cros_ec_led_trigger_activate, 95 }; 96 97 static int cros_ec_led_brightness_set_blocking(struct led_classdev *led_cdev, 98 enum led_brightness brightness) 99 { 100 struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev); 101 union cros_ec_led_cmd_data arg = {}; 102 enum ec_led_colors led_color; 103 struct mc_subled *subled; 104 size_t i; 105 106 led_mc_calc_color_components(&priv->led_mc_cdev, brightness); 107 108 arg.req.led_id = priv->led_id; 109 110 for (i = 0; i < priv->led_mc_cdev.num_colors; i++) { 111 subled = &priv->led_mc_cdev.subled_info[i]; 112 led_color = cros_ec_linux_to_ec_id[subled->color_index]; 113 arg.req.brightness[led_color] = subled->brightness; 114 } 115 116 return cros_ec_led_send_cmd(priv->cros_ec, &arg); 117 } 118 119 static int cros_ec_led_count_subleds(struct device *dev, 120 struct ec_response_led_control *resp, 121 unsigned int *max_brightness) 122 { 123 unsigned int range, common_range = 0; 124 int num_subleds = 0; 125 size_t i; 126 127 for (i = 0; i < EC_LED_COLOR_COUNT; i++) { 128 range = resp->brightness_range[i]; 129 130 if (!range) 131 continue; 132 133 num_subleds++; 134 135 if (!common_range) 136 common_range = range; 137 138 if (common_range != range) { 139 /* The multicolor LED API expects a uniform max_brightness */ 140 dev_err(dev, "Inconsistent LED brightness values\n"); 141 return -EINVAL; 142 } 143 } 144 145 *max_brightness = common_range; 146 return num_subleds; 147 } 148 149 static const char *cros_ec_led_get_color_name(struct led_classdev_mc *led_mc_cdev) 150 { 151 int color; 152 153 if (led_mc_cdev->num_colors == 1) 154 color = led_mc_cdev->subled_info[0].color_index; 155 else 156 color = LED_COLOR_ID_MULTI; 157 158 return led_get_color_name(color); 159 } 160 161 static int cros_ec_led_probe_one(struct device *dev, struct cros_ec_device *cros_ec, 162 enum ec_led_id id) 163 { 164 union cros_ec_led_cmd_data arg = {}; 165 struct cros_ec_led_priv *priv; 166 struct led_classdev *led_cdev; 167 struct mc_subled *subleds; 168 int i, ret, num_subleds; 169 size_t subled; 170 171 arg.req.led_id = id; 172 arg.req.flags = EC_LED_FLAGS_QUERY; 173 ret = cros_ec_led_send_cmd(cros_ec, &arg); 174 if (ret == -EINVAL) 175 return 0; /* Unknown LED, skip */ 176 if (ret == -EOPNOTSUPP) 177 return -ENODEV; 178 if (ret < 0) 179 return ret; 180 181 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 182 if (!priv) 183 return -ENOMEM; 184 185 num_subleds = cros_ec_led_count_subleds(dev, &arg.resp, 186 &priv->led_mc_cdev.led_cdev.max_brightness); 187 if (num_subleds < 0) 188 return num_subleds; 189 if (num_subleds == 0) 190 return 0; /* LED without any colors, skip */ 191 192 priv->cros_ec = cros_ec; 193 priv->led_id = id; 194 195 subleds = devm_kcalloc(dev, num_subleds, sizeof(*subleds), GFP_KERNEL); 196 if (!subleds) 197 return -ENOMEM; 198 199 subled = 0; 200 for (i = 0; i < EC_LED_COLOR_COUNT; i++) { 201 if (!arg.resp.brightness_range[i]) 202 continue; 203 204 subleds[subled].color_index = cros_ec_led_to_linux_id[i]; 205 if (subled == 0) 206 subleds[subled].intensity = 100; 207 subled++; 208 } 209 210 priv->led_mc_cdev.subled_info = subleds; 211 priv->led_mc_cdev.num_colors = num_subleds; 212 213 led_cdev = &priv->led_mc_cdev.led_cdev; 214 led_cdev->brightness_set_blocking = cros_ec_led_brightness_set_blocking; 215 led_cdev->trigger_type = &cros_ec_led_trigger_type; 216 led_cdev->default_trigger = cros_ec_led_trigger.name; 217 led_cdev->hw_control_trigger = cros_ec_led_trigger.name; 218 219 led_cdev->name = devm_kasprintf(dev, GFP_KERNEL, "chromeos:%s:%s", 220 cros_ec_led_get_color_name(&priv->led_mc_cdev), 221 cros_ec_led_functions[id]); 222 if (!led_cdev->name) 223 return -ENOMEM; 224 225 return devm_led_classdev_multicolor_register(dev, &priv->led_mc_cdev); 226 } 227 228 static int cros_ec_led_probe(struct platform_device *pdev) 229 { 230 struct device *dev = &pdev->dev; 231 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent); 232 struct cros_ec_device *cros_ec = ec_dev->ec_dev; 233 int i, ret = 0; 234 235 ret = devm_led_trigger_register(dev, &cros_ec_led_trigger); 236 if (ret) 237 return ret; 238 239 for (i = 0; i < EC_LED_ID_COUNT; i++) { 240 ret = cros_ec_led_probe_one(dev, cros_ec, i); 241 if (ret) 242 break; 243 } 244 245 return ret; 246 } 247 248 static const struct platform_device_id cros_ec_led_id[] = { 249 { "cros-ec-led", 0 }, 250 {} 251 }; 252 253 static struct platform_driver cros_ec_led_driver = { 254 .driver.name = "cros-ec-led", 255 .probe = cros_ec_led_probe, 256 .id_table = cros_ec_led_id, 257 }; 258 module_platform_driver(cros_ec_led_driver); 259 260 MODULE_DEVICE_TABLE(platform, cros_ec_led_id); 261 MODULE_DESCRIPTION("ChromeOS EC LED Driver"); 262 MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net"); 263 MODULE_LICENSE("GPL"); 264