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 if (!num_subleds) 146 return -EINVAL; 147 148 *max_brightness = common_range; 149 return num_subleds; 150 } 151 152 static const char *cros_ec_led_get_color_name(struct led_classdev_mc *led_mc_cdev) 153 { 154 int color; 155 156 if (led_mc_cdev->num_colors == 1) 157 color = led_mc_cdev->subled_info[0].color_index; 158 else 159 color = LED_COLOR_ID_MULTI; 160 161 return led_get_color_name(color); 162 } 163 164 static int cros_ec_led_probe_one(struct device *dev, struct cros_ec_device *cros_ec, 165 enum ec_led_id id) 166 { 167 union cros_ec_led_cmd_data arg = {}; 168 struct cros_ec_led_priv *priv; 169 struct led_classdev *led_cdev; 170 struct mc_subled *subleds; 171 int i, ret, num_subleds; 172 size_t subled; 173 174 arg.req.led_id = id; 175 arg.req.flags = EC_LED_FLAGS_QUERY; 176 ret = cros_ec_led_send_cmd(cros_ec, &arg); 177 if (ret == -EINVAL) 178 return 0; /* Unknown LED, skip */ 179 if (ret == -EOPNOTSUPP) 180 return -ENODEV; 181 if (ret < 0) 182 return ret; 183 184 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 185 if (!priv) 186 return -ENOMEM; 187 188 num_subleds = cros_ec_led_count_subleds(dev, &arg.resp, 189 &priv->led_mc_cdev.led_cdev.max_brightness); 190 if (num_subleds < 0) 191 return num_subleds; 192 193 priv->cros_ec = cros_ec; 194 priv->led_id = id; 195 196 subleds = devm_kcalloc(dev, num_subleds, sizeof(*subleds), GFP_KERNEL); 197 if (!subleds) 198 return -ENOMEM; 199 200 subled = 0; 201 for (i = 0; i < EC_LED_COLOR_COUNT; i++) { 202 if (!arg.resp.brightness_range[i]) 203 continue; 204 205 subleds[subled].color_index = cros_ec_led_to_linux_id[i]; 206 if (subled == 0) 207 subleds[subled].intensity = 100; 208 subled++; 209 } 210 211 priv->led_mc_cdev.subled_info = subleds; 212 priv->led_mc_cdev.num_colors = num_subleds; 213 214 led_cdev = &priv->led_mc_cdev.led_cdev; 215 led_cdev->brightness_set_blocking = cros_ec_led_brightness_set_blocking; 216 led_cdev->trigger_type = &cros_ec_led_trigger_type; 217 led_cdev->default_trigger = cros_ec_led_trigger.name; 218 led_cdev->hw_control_trigger = cros_ec_led_trigger.name; 219 220 led_cdev->name = devm_kasprintf(dev, GFP_KERNEL, "chromeos:%s:%s", 221 cros_ec_led_get_color_name(&priv->led_mc_cdev), 222 cros_ec_led_functions[id]); 223 if (!led_cdev->name) 224 return -ENOMEM; 225 226 return devm_led_classdev_multicolor_register(dev, &priv->led_mc_cdev); 227 } 228 229 static int cros_ec_led_probe(struct platform_device *pdev) 230 { 231 struct device *dev = &pdev->dev; 232 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent); 233 struct cros_ec_device *cros_ec = ec_dev->ec_dev; 234 int i, ret = 0; 235 236 ret = devm_led_trigger_register(dev, &cros_ec_led_trigger); 237 if (ret) 238 return ret; 239 240 for (i = 0; i < EC_LED_ID_COUNT; i++) { 241 ret = cros_ec_led_probe_one(dev, cros_ec, i); 242 if (ret) 243 break; 244 } 245 246 return ret; 247 } 248 249 static const struct platform_device_id cros_ec_led_id[] = { 250 { "cros-ec-led", 0 }, 251 {} 252 }; 253 254 static struct platform_driver cros_ec_led_driver = { 255 .driver.name = "cros-ec-led", 256 .probe = cros_ec_led_probe, 257 .id_table = cros_ec_led_id, 258 }; 259 module_platform_driver(cros_ec_led_driver); 260 261 MODULE_DEVICE_TABLE(platform, cros_ec_led_id); 262 MODULE_DESCRIPTION("ChromeOS EC LED Driver"); 263 MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net"); 264 MODULE_LICENSE("GPL"); 265