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-usbpd-charger", }, 91 { .name = "cros-usbpd-logger", }, 92 }; 93 94 static const struct mfd_cell cros_usbpd_notify_cells[] = { 95 { .name = "cros-usbpd-notify", }, 96 }; 97 98 static const struct mfd_cell cros_ec_wdt_cells[] = { 99 { .name = "cros-ec-wdt", } 100 }; 101 102 static const struct mfd_cell cros_ec_keyboard_leds_cells[] = { 103 { .name = "cros-keyboard-leds", }, 104 }; 105 106 static const struct cros_feature_to_cells cros_subdevices[] = { 107 { 108 .id = EC_FEATURE_CEC, 109 .mfd_cells = cros_ec_cec_cells, 110 .num_cells = ARRAY_SIZE(cros_ec_cec_cells), 111 }, 112 { 113 .id = EC_FEATURE_GPIO, 114 .mfd_cells = cros_ec_gpio_cells, 115 .num_cells = ARRAY_SIZE(cros_ec_gpio_cells), 116 }, 117 { 118 .id = EC_FEATURE_RTC, 119 .mfd_cells = cros_ec_rtc_cells, 120 .num_cells = ARRAY_SIZE(cros_ec_rtc_cells), 121 }, 122 { 123 .id = EC_FEATURE_USB_PD, 124 .mfd_cells = cros_usbpd_charger_cells, 125 .num_cells = ARRAY_SIZE(cros_usbpd_charger_cells), 126 }, 127 { 128 .id = EC_FEATURE_HANG_DETECT, 129 .mfd_cells = cros_ec_wdt_cells, 130 .num_cells = ARRAY_SIZE(cros_ec_wdt_cells), 131 }, 132 { 133 .id = EC_FEATURE_PWM_KEYB, 134 .mfd_cells = cros_ec_keyboard_leds_cells, 135 .num_cells = ARRAY_SIZE(cros_ec_keyboard_leds_cells), 136 }, 137 }; 138 139 static const struct mfd_cell cros_ec_platform_cells[] = { 140 { .name = "cros-ec-chardev", }, 141 { .name = "cros-ec-debugfs", }, 142 { .name = "cros-ec-sysfs", }, 143 }; 144 145 static const struct mfd_cell cros_ec_pchg_cells[] = { 146 { .name = "cros-ec-pchg", }, 147 }; 148 149 static const struct mfd_cell cros_ec_lightbar_cells[] = { 150 { .name = "cros-ec-lightbar", } 151 }; 152 153 static const struct mfd_cell cros_ec_vbc_cells[] = { 154 { .name = "cros-ec-vbc", } 155 }; 156 157 static void cros_ec_class_release(struct device *dev) 158 { 159 kfree(to_cros_ec_dev(dev)); 160 } 161 162 static int ec_device_probe(struct platform_device *pdev) 163 { 164 int retval = -ENOMEM; 165 struct device_node *node; 166 struct device *dev = &pdev->dev; 167 struct cros_ec_platform *ec_platform = dev_get_platdata(dev); 168 struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL); 169 struct ec_response_pchg_count pchg_count; 170 int i; 171 172 if (!ec) 173 return retval; 174 175 dev_set_drvdata(dev, ec); 176 ec->ec_dev = dev_get_drvdata(dev->parent); 177 ec->dev = dev; 178 ec->cmd_offset = ec_platform->cmd_offset; 179 ec->features.flags[0] = -1U; /* Not cached yet */ 180 ec->features.flags[1] = -1U; /* Not cached yet */ 181 device_initialize(&ec->class_dev); 182 183 for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) { 184 /* 185 * Check whether this is actually a dedicated MCU rather 186 * than an standard EC. 187 */ 188 if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) { 189 dev_info(dev, "CrOS %s MCU detected\n", 190 cros_mcu_devices[i].desc); 191 /* 192 * Help userspace differentiating ECs from other MCU, 193 * regardless of the probing order. 194 */ 195 ec_platform->ec_name = cros_mcu_devices[i].name; 196 break; 197 } 198 } 199 200 /* 201 * Add the class device 202 */ 203 ec->class_dev.class = &cros_class; 204 ec->class_dev.parent = dev; 205 ec->class_dev.release = cros_ec_class_release; 206 207 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name); 208 if (retval) { 209 dev_err(dev, "dev_set_name failed => %d\n", retval); 210 goto failed; 211 } 212 213 retval = device_add(&ec->class_dev); 214 if (retval) 215 goto failed; 216 217 /* check whether this EC is a sensor hub. */ 218 if (cros_ec_get_sensor_count(ec) > 0) { 219 retval = mfd_add_hotplug_devices(ec->dev, 220 cros_ec_sensorhub_cells, 221 ARRAY_SIZE(cros_ec_sensorhub_cells)); 222 if (retval) 223 dev_err(ec->dev, "failed to add %s subdevice: %d\n", 224 cros_ec_sensorhub_cells->name, retval); 225 } 226 227 /* 228 * The following subdevices can be detected by sending the 229 * EC_FEATURE_GET_CMD Embedded Controller device. 230 */ 231 for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) { 232 if (cros_ec_check_features(ec, cros_subdevices[i].id)) { 233 retval = mfd_add_hotplug_devices(ec->dev, 234 cros_subdevices[i].mfd_cells, 235 cros_subdevices[i].num_cells); 236 if (retval) 237 dev_err(ec->dev, 238 "failed to add %s subdevice: %d\n", 239 cros_subdevices[i].mfd_cells->name, 240 retval); 241 } 242 } 243 244 /* 245 * Lightbar is a special case. Newer devices support autodetection, 246 * but older ones do not. 247 */ 248 if (cros_ec_check_features(ec, EC_FEATURE_LIGHTBAR) || 249 dmi_match(DMI_PRODUCT_NAME, "Link")) { 250 retval = mfd_add_hotplug_devices(ec->dev, 251 cros_ec_lightbar_cells, 252 ARRAY_SIZE(cros_ec_lightbar_cells)); 253 if (retval) 254 dev_warn(ec->dev, "failed to add lightbar: %d\n", 255 retval); 256 } 257 258 /* 259 * The PD notifier driver cell is separate since it only needs to be 260 * explicitly added on platforms that don't have the PD notifier ACPI 261 * device entry defined. 262 */ 263 if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) { 264 if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) { 265 retval = mfd_add_hotplug_devices(ec->dev, 266 cros_usbpd_notify_cells, 267 ARRAY_SIZE(cros_usbpd_notify_cells)); 268 if (retval) 269 dev_err(ec->dev, 270 "failed to add PD notify devices: %d\n", 271 retval); 272 } 273 } 274 275 /* 276 * The PCHG device cannot be detected by sending EC_FEATURE_GET_CMD, but 277 * it can be detected by querying the number of peripheral chargers. 278 */ 279 retval = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_PCHG_COUNT, NULL, 0, 280 &pchg_count, sizeof(pchg_count)); 281 if (retval >= 0 && pchg_count.port_count) { 282 retval = mfd_add_hotplug_devices(ec->dev, 283 cros_ec_pchg_cells, 284 ARRAY_SIZE(cros_ec_pchg_cells)); 285 if (retval) 286 dev_warn(ec->dev, "failed to add pchg: %d\n", 287 retval); 288 } 289 290 /* 291 * The following subdevices cannot be detected by sending the 292 * EC_FEATURE_GET_CMD to the Embedded Controller device. 293 */ 294 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells, 295 ARRAY_SIZE(cros_ec_platform_cells)); 296 if (retval) 297 dev_warn(ec->dev, 298 "failed to add cros-ec platform devices: %d\n", 299 retval); 300 301 /* Check whether this EC instance has a VBC NVRAM */ 302 node = ec->ec_dev->dev->of_node; 303 if (of_property_read_bool(node, "google,has-vbc-nvram")) { 304 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells, 305 ARRAY_SIZE(cros_ec_vbc_cells)); 306 if (retval) 307 dev_warn(ec->dev, "failed to add VBC devices: %d\n", 308 retval); 309 } 310 311 return 0; 312 313 failed: 314 put_device(&ec->class_dev); 315 return retval; 316 } 317 318 static void ec_device_remove(struct platform_device *pdev) 319 { 320 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); 321 322 mfd_remove_devices(ec->dev); 323 device_unregister(&ec->class_dev); 324 } 325 326 static const struct platform_device_id cros_ec_id[] = { 327 { DRV_NAME, 0 }, 328 { /* sentinel */ } 329 }; 330 MODULE_DEVICE_TABLE(platform, cros_ec_id); 331 332 static struct platform_driver cros_ec_dev_driver = { 333 .driver = { 334 .name = DRV_NAME, 335 }, 336 .id_table = cros_ec_id, 337 .probe = ec_device_probe, 338 .remove_new = ec_device_remove, 339 }; 340 341 static int __init cros_ec_dev_init(void) 342 { 343 int ret; 344 345 ret = class_register(&cros_class); 346 if (ret) { 347 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n"); 348 return ret; 349 } 350 351 /* Register the driver */ 352 ret = platform_driver_register(&cros_ec_dev_driver); 353 if (ret < 0) { 354 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret); 355 goto failed_devreg; 356 } 357 return 0; 358 359 failed_devreg: 360 class_unregister(&cros_class); 361 return ret; 362 } 363 364 static void __exit cros_ec_dev_exit(void) 365 { 366 platform_driver_unregister(&cros_ec_dev_driver); 367 class_unregister(&cros_class); 368 } 369 370 module_init(cros_ec_dev_init); 371 module_exit(cros_ec_dev_exit); 372 373 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>"); 374 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller"); 375 MODULE_VERSION("1.0"); 376 MODULE_LICENSE("GPL"); 377