1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space 4 * 5 * Copyright (C) 2014 Google, Inc. 6 */ 7 8 #include <linux/dmi.h> 9 #include <linux/kconfig.h> 10 #include <linux/mfd/core.h> 11 #include <linux/module.h> 12 #include <linux/mod_devicetable.h> 13 #include <linux/of.h> 14 #include <linux/platform_device.h> 15 #include <linux/platform_data/cros_ec_chardev.h> 16 #include <linux/platform_data/cros_ec_commands.h> 17 #include <linux/platform_data/cros_ec_proto.h> 18 #include <linux/slab.h> 19 20 #define DRV_NAME "cros-ec-dev" 21 22 static struct class cros_class = { 23 .name = "chromeos", 24 }; 25 26 /** 27 * struct cros_feature_to_name - CrOS feature id to name/short description. 28 * @id: The feature identifier. 29 * @name: Device name associated with the feature id. 30 * @desc: Short name that will be displayed. 31 */ 32 struct cros_feature_to_name { 33 unsigned int id; 34 const char *name; 35 const char *desc; 36 }; 37 38 /** 39 * struct cros_feature_to_cells - CrOS feature id to mfd cells association. 40 * @id: The feature identifier. 41 * @mfd_cells: Pointer to the array of mfd cells that needs to be added. 42 * @num_cells: Number of mfd cells into the array. 43 */ 44 struct cros_feature_to_cells { 45 unsigned int id; 46 const struct mfd_cell *mfd_cells; 47 unsigned int num_cells; 48 }; 49 50 static const struct cros_feature_to_name cros_mcu_devices[] = { 51 { 52 .id = EC_FEATURE_FINGERPRINT, 53 .name = CROS_EC_DEV_FP_NAME, 54 .desc = "Fingerprint", 55 }, 56 { 57 .id = EC_FEATURE_ISH, 58 .name = CROS_EC_DEV_ISH_NAME, 59 .desc = "Integrated Sensor Hub", 60 }, 61 { 62 .id = EC_FEATURE_SCP, 63 .name = CROS_EC_DEV_SCP_NAME, 64 .desc = "System Control Processor", 65 }, 66 { 67 .id = EC_FEATURE_TOUCHPAD, 68 .name = CROS_EC_DEV_TP_NAME, 69 .desc = "Touchpad", 70 }, 71 }; 72 73 static const struct mfd_cell cros_ec_cec_cells[] = { 74 { .name = "cros-ec-cec", }, 75 }; 76 77 static const struct mfd_cell cros_ec_gpio_cells[] = { 78 { .name = "cros-ec-gpio", }, 79 }; 80 81 static const struct mfd_cell cros_ec_rtc_cells[] = { 82 { .name = "cros-ec-rtc", }, 83 }; 84 85 static const struct mfd_cell cros_ec_sensorhub_cells[] = { 86 { .name = "cros-ec-sensorhub", }, 87 }; 88 89 static const struct mfd_cell cros_usbpd_charger_cells[] = { 90 { .name = "cros-charge-control", }, 91 { .name = "cros-usbpd-charger", }, 92 { .name = "cros-usbpd-logger", }, 93 }; 94 95 static const struct mfd_cell cros_usbpd_notify_cells[] = { 96 { .name = "cros-usbpd-notify", }, 97 }; 98 99 static const struct mfd_cell cros_ec_wdt_cells[] = { 100 { .name = "cros-ec-wdt", } 101 }; 102 103 static const struct mfd_cell cros_ec_led_cells[] = { 104 { .name = "cros-ec-led", }, 105 }; 106 107 static const struct mfd_cell cros_ec_keyboard_leds_cells[] = { 108 { .name = "cros-keyboard-leds", }, 109 }; 110 111 static const struct cros_feature_to_cells cros_subdevices[] = { 112 { 113 .id = EC_FEATURE_CEC, 114 .mfd_cells = cros_ec_cec_cells, 115 .num_cells = ARRAY_SIZE(cros_ec_cec_cells), 116 }, 117 { 118 .id = EC_FEATURE_GPIO, 119 .mfd_cells = cros_ec_gpio_cells, 120 .num_cells = ARRAY_SIZE(cros_ec_gpio_cells), 121 }, 122 { 123 .id = EC_FEATURE_RTC, 124 .mfd_cells = cros_ec_rtc_cells, 125 .num_cells = ARRAY_SIZE(cros_ec_rtc_cells), 126 }, 127 { 128 .id = EC_FEATURE_USB_PD, 129 .mfd_cells = cros_usbpd_charger_cells, 130 .num_cells = ARRAY_SIZE(cros_usbpd_charger_cells), 131 }, 132 { 133 .id = EC_FEATURE_HANG_DETECT, 134 .mfd_cells = cros_ec_wdt_cells, 135 .num_cells = ARRAY_SIZE(cros_ec_wdt_cells), 136 }, 137 { 138 .id = EC_FEATURE_LED, 139 .mfd_cells = cros_ec_led_cells, 140 .num_cells = ARRAY_SIZE(cros_ec_led_cells), 141 }, 142 { 143 .id = EC_FEATURE_PWM_KEYB, 144 .mfd_cells = cros_ec_keyboard_leds_cells, 145 .num_cells = ARRAY_SIZE(cros_ec_keyboard_leds_cells), 146 }, 147 }; 148 149 static const struct mfd_cell cros_ec_platform_cells[] = { 150 { .name = "cros-ec-chardev", }, 151 { .name = "cros-ec-debugfs", }, 152 { .name = "cros-ec-hwmon", }, 153 { .name = "cros-ec-sysfs", }, 154 }; 155 156 static const struct mfd_cell cros_ec_pchg_cells[] = { 157 { .name = "cros-ec-pchg", }, 158 }; 159 160 static const struct mfd_cell cros_ec_lightbar_cells[] = { 161 { .name = "cros-ec-lightbar", } 162 }; 163 164 static const struct mfd_cell cros_ec_vbc_cells[] = { 165 { .name = "cros-ec-vbc", } 166 }; 167 168 static void cros_ec_class_release(struct device *dev) 169 { 170 kfree(to_cros_ec_dev(dev)); 171 } 172 173 static int ec_device_probe(struct platform_device *pdev) 174 { 175 int retval = -ENOMEM; 176 struct device_node *node; 177 struct device *dev = &pdev->dev; 178 struct cros_ec_platform *ec_platform = dev_get_platdata(dev); 179 struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL); 180 struct ec_response_pchg_count pchg_count; 181 int i; 182 183 if (!ec) 184 return retval; 185 186 dev_set_drvdata(dev, ec); 187 ec->ec_dev = dev_get_drvdata(dev->parent); 188 ec->dev = dev; 189 ec->cmd_offset = ec_platform->cmd_offset; 190 ec->features.flags[0] = -1U; /* Not cached yet */ 191 ec->features.flags[1] = -1U; /* Not cached yet */ 192 device_initialize(&ec->class_dev); 193 194 for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) { 195 /* 196 * Check whether this is actually a dedicated MCU rather 197 * than an standard EC. 198 */ 199 if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) { 200 dev_info(dev, "CrOS %s MCU detected\n", 201 cros_mcu_devices[i].desc); 202 /* 203 * Help userspace differentiating ECs from other MCU, 204 * regardless of the probing order. 205 */ 206 ec_platform->ec_name = cros_mcu_devices[i].name; 207 break; 208 } 209 } 210 211 /* 212 * Add the class device 213 */ 214 ec->class_dev.class = &cros_class; 215 ec->class_dev.parent = dev; 216 ec->class_dev.release = cros_ec_class_release; 217 218 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name); 219 if (retval) { 220 dev_err(dev, "dev_set_name failed => %d\n", retval); 221 goto failed; 222 } 223 224 retval = device_add(&ec->class_dev); 225 if (retval) 226 goto failed; 227 228 /* check whether this EC is a sensor hub. */ 229 if (cros_ec_get_sensor_count(ec) > 0) { 230 retval = mfd_add_hotplug_devices(ec->dev, 231 cros_ec_sensorhub_cells, 232 ARRAY_SIZE(cros_ec_sensorhub_cells)); 233 if (retval) 234 dev_err(ec->dev, "failed to add %s subdevice: %d\n", 235 cros_ec_sensorhub_cells->name, retval); 236 } 237 238 /* 239 * The following subdevices can be detected by sending the 240 * EC_FEATURE_GET_CMD Embedded Controller device. 241 */ 242 for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) { 243 if (cros_ec_check_features(ec, cros_subdevices[i].id)) { 244 retval = mfd_add_hotplug_devices(ec->dev, 245 cros_subdevices[i].mfd_cells, 246 cros_subdevices[i].num_cells); 247 if (retval) 248 dev_err(ec->dev, 249 "failed to add %s subdevice: %d\n", 250 cros_subdevices[i].mfd_cells->name, 251 retval); 252 } 253 } 254 255 /* 256 * Lightbar is a special case. Newer devices support autodetection, 257 * but older ones do not. 258 */ 259 if (cros_ec_check_features(ec, EC_FEATURE_LIGHTBAR) || 260 dmi_match(DMI_PRODUCT_NAME, "Link")) { 261 retval = mfd_add_hotplug_devices(ec->dev, 262 cros_ec_lightbar_cells, 263 ARRAY_SIZE(cros_ec_lightbar_cells)); 264 if (retval) 265 dev_warn(ec->dev, "failed to add lightbar: %d\n", 266 retval); 267 } 268 269 /* 270 * The PD notifier driver cell is separate since it only needs to be 271 * explicitly added on platforms that don't have the PD notifier ACPI 272 * device entry defined. 273 */ 274 if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) { 275 if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) { 276 retval = mfd_add_hotplug_devices(ec->dev, 277 cros_usbpd_notify_cells, 278 ARRAY_SIZE(cros_usbpd_notify_cells)); 279 if (retval) 280 dev_err(ec->dev, 281 "failed to add PD notify devices: %d\n", 282 retval); 283 } 284 } 285 286 /* 287 * The PCHG device cannot be detected by sending EC_FEATURE_GET_CMD, but 288 * it can be detected by querying the number of peripheral chargers. 289 */ 290 retval = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_PCHG_COUNT, NULL, 0, 291 &pchg_count, sizeof(pchg_count)); 292 if (retval >= 0 && pchg_count.port_count) { 293 retval = mfd_add_hotplug_devices(ec->dev, 294 cros_ec_pchg_cells, 295 ARRAY_SIZE(cros_ec_pchg_cells)); 296 if (retval) 297 dev_warn(ec->dev, "failed to add pchg: %d\n", 298 retval); 299 } 300 301 /* 302 * The following subdevices cannot be detected by sending the 303 * EC_FEATURE_GET_CMD to the Embedded Controller device. 304 */ 305 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells, 306 ARRAY_SIZE(cros_ec_platform_cells)); 307 if (retval) 308 dev_warn(ec->dev, 309 "failed to add cros-ec platform devices: %d\n", 310 retval); 311 312 /* Check whether this EC instance has a VBC NVRAM */ 313 node = ec->ec_dev->dev->of_node; 314 if (of_property_read_bool(node, "google,has-vbc-nvram")) { 315 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells, 316 ARRAY_SIZE(cros_ec_vbc_cells)); 317 if (retval) 318 dev_warn(ec->dev, "failed to add VBC devices: %d\n", 319 retval); 320 } 321 322 return 0; 323 324 failed: 325 put_device(&ec->class_dev); 326 return retval; 327 } 328 329 static void ec_device_remove(struct platform_device *pdev) 330 { 331 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); 332 333 mfd_remove_devices(ec->dev); 334 device_unregister(&ec->class_dev); 335 } 336 337 static const struct platform_device_id cros_ec_id[] = { 338 { DRV_NAME, 0 }, 339 { /* sentinel */ } 340 }; 341 MODULE_DEVICE_TABLE(platform, cros_ec_id); 342 343 static struct platform_driver cros_ec_dev_driver = { 344 .driver = { 345 .name = DRV_NAME, 346 }, 347 .id_table = cros_ec_id, 348 .probe = ec_device_probe, 349 .remove_new = ec_device_remove, 350 }; 351 352 static int __init cros_ec_dev_init(void) 353 { 354 int ret; 355 356 ret = class_register(&cros_class); 357 if (ret) { 358 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n"); 359 return ret; 360 } 361 362 /* Register the driver */ 363 ret = platform_driver_register(&cros_ec_dev_driver); 364 if (ret < 0) { 365 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret); 366 goto failed_devreg; 367 } 368 return 0; 369 370 failed_devreg: 371 class_unregister(&cros_class); 372 return ret; 373 } 374 375 static void __exit cros_ec_dev_exit(void) 376 { 377 platform_driver_unregister(&cros_ec_dev_driver); 378 class_unregister(&cros_class); 379 } 380 381 module_init(cros_ec_dev_init); 382 module_exit(cros_ec_dev_exit); 383 384 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>"); 385 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller"); 386 MODULE_VERSION("1.0"); 387 MODULE_LICENSE("GPL"); 388