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_rtc_cells[] = { 78 { .name = "cros-ec-rtc", }, 79 }; 80 81 static const struct mfd_cell cros_ec_sensorhub_cells[] = { 82 { .name = "cros-ec-sensorhub", }, 83 }; 84 85 static const struct mfd_cell cros_usbpd_charger_cells[] = { 86 { .name = "cros-usbpd-charger", }, 87 { .name = "cros-usbpd-logger", }, 88 }; 89 90 static const struct mfd_cell cros_usbpd_notify_cells[] = { 91 { .name = "cros-usbpd-notify", }, 92 }; 93 94 static const struct cros_feature_to_cells cros_subdevices[] = { 95 { 96 .id = EC_FEATURE_CEC, 97 .mfd_cells = cros_ec_cec_cells, 98 .num_cells = ARRAY_SIZE(cros_ec_cec_cells), 99 }, 100 { 101 .id = EC_FEATURE_RTC, 102 .mfd_cells = cros_ec_rtc_cells, 103 .num_cells = ARRAY_SIZE(cros_ec_rtc_cells), 104 }, 105 { 106 .id = EC_FEATURE_USB_PD, 107 .mfd_cells = cros_usbpd_charger_cells, 108 .num_cells = ARRAY_SIZE(cros_usbpd_charger_cells), 109 }, 110 }; 111 112 static const struct mfd_cell cros_ec_platform_cells[] = { 113 { .name = "cros-ec-chardev", }, 114 { .name = "cros-ec-debugfs", }, 115 { .name = "cros-ec-sysfs", }, 116 }; 117 118 static const struct mfd_cell cros_ec_pchg_cells[] = { 119 { .name = "cros-ec-pchg", }, 120 }; 121 122 static const struct mfd_cell cros_ec_lightbar_cells[] = { 123 { .name = "cros-ec-lightbar", } 124 }; 125 126 static const struct mfd_cell cros_ec_vbc_cells[] = { 127 { .name = "cros-ec-vbc", } 128 }; 129 130 static void cros_ec_class_release(struct device *dev) 131 { 132 kfree(to_cros_ec_dev(dev)); 133 } 134 135 static int ec_device_probe(struct platform_device *pdev) 136 { 137 int retval = -ENOMEM; 138 struct device_node *node; 139 struct device *dev = &pdev->dev; 140 struct cros_ec_platform *ec_platform = dev_get_platdata(dev); 141 struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL); 142 struct ec_response_pchg_count pchg_count; 143 int i; 144 145 if (!ec) 146 return retval; 147 148 dev_set_drvdata(dev, ec); 149 ec->ec_dev = dev_get_drvdata(dev->parent); 150 ec->dev = dev; 151 ec->cmd_offset = ec_platform->cmd_offset; 152 ec->features.flags[0] = -1U; /* Not cached yet */ 153 ec->features.flags[1] = -1U; /* Not cached yet */ 154 device_initialize(&ec->class_dev); 155 156 for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) { 157 /* 158 * Check whether this is actually a dedicated MCU rather 159 * than an standard EC. 160 */ 161 if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) { 162 dev_info(dev, "CrOS %s MCU detected\n", 163 cros_mcu_devices[i].desc); 164 /* 165 * Help userspace differentiating ECs from other MCU, 166 * regardless of the probing order. 167 */ 168 ec_platform->ec_name = cros_mcu_devices[i].name; 169 break; 170 } 171 } 172 173 /* 174 * Add the class device 175 */ 176 ec->class_dev.class = &cros_class; 177 ec->class_dev.parent = dev; 178 ec->class_dev.release = cros_ec_class_release; 179 180 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name); 181 if (retval) { 182 dev_err(dev, "dev_set_name failed => %d\n", retval); 183 goto failed; 184 } 185 186 retval = device_add(&ec->class_dev); 187 if (retval) 188 goto failed; 189 190 /* check whether this EC is a sensor hub. */ 191 if (cros_ec_get_sensor_count(ec) > 0) { 192 retval = mfd_add_hotplug_devices(ec->dev, 193 cros_ec_sensorhub_cells, 194 ARRAY_SIZE(cros_ec_sensorhub_cells)); 195 if (retval) 196 dev_err(ec->dev, "failed to add %s subdevice: %d\n", 197 cros_ec_sensorhub_cells->name, retval); 198 } 199 200 /* 201 * The following subdevices can be detected by sending the 202 * EC_FEATURE_GET_CMD Embedded Controller device. 203 */ 204 for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) { 205 if (cros_ec_check_features(ec, cros_subdevices[i].id)) { 206 retval = mfd_add_hotplug_devices(ec->dev, 207 cros_subdevices[i].mfd_cells, 208 cros_subdevices[i].num_cells); 209 if (retval) 210 dev_err(ec->dev, 211 "failed to add %s subdevice: %d\n", 212 cros_subdevices[i].mfd_cells->name, 213 retval); 214 } 215 } 216 217 /* 218 * Lightbar is a special case. Newer devices support autodetection, 219 * but older ones do not. 220 */ 221 if (cros_ec_check_features(ec, EC_FEATURE_LIGHTBAR) || 222 dmi_match(DMI_PRODUCT_NAME, "Link")) { 223 retval = mfd_add_hotplug_devices(ec->dev, 224 cros_ec_lightbar_cells, 225 ARRAY_SIZE(cros_ec_lightbar_cells)); 226 if (retval) 227 dev_warn(ec->dev, "failed to add lightbar: %d\n", 228 retval); 229 } 230 231 /* 232 * The PD notifier driver cell is separate since it only needs to be 233 * explicitly added on platforms that don't have the PD notifier ACPI 234 * device entry defined. 235 */ 236 if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) { 237 if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) { 238 retval = mfd_add_hotplug_devices(ec->dev, 239 cros_usbpd_notify_cells, 240 ARRAY_SIZE(cros_usbpd_notify_cells)); 241 if (retval) 242 dev_err(ec->dev, 243 "failed to add PD notify devices: %d\n", 244 retval); 245 } 246 } 247 248 /* 249 * The PCHG device cannot be detected by sending EC_FEATURE_GET_CMD, but 250 * it can be detected by querying the number of peripheral chargers. 251 */ 252 retval = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_PCHG_COUNT, NULL, 0, 253 &pchg_count, sizeof(pchg_count)); 254 if (retval >= 0 && pchg_count.port_count) { 255 retval = mfd_add_hotplug_devices(ec->dev, 256 cros_ec_pchg_cells, 257 ARRAY_SIZE(cros_ec_pchg_cells)); 258 if (retval) 259 dev_warn(ec->dev, "failed to add pchg: %d\n", 260 retval); 261 } 262 263 /* 264 * The following subdevices cannot be detected by sending the 265 * EC_FEATURE_GET_CMD to the Embedded Controller device. 266 */ 267 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells, 268 ARRAY_SIZE(cros_ec_platform_cells)); 269 if (retval) 270 dev_warn(ec->dev, 271 "failed to add cros-ec platform devices: %d\n", 272 retval); 273 274 /* Check whether this EC instance has a VBC NVRAM */ 275 node = ec->ec_dev->dev->of_node; 276 if (of_property_read_bool(node, "google,has-vbc-nvram")) { 277 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells, 278 ARRAY_SIZE(cros_ec_vbc_cells)); 279 if (retval) 280 dev_warn(ec->dev, "failed to add VBC devices: %d\n", 281 retval); 282 } 283 284 return 0; 285 286 failed: 287 put_device(&ec->class_dev); 288 return retval; 289 } 290 291 static void ec_device_remove(struct platform_device *pdev) 292 { 293 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); 294 295 mfd_remove_devices(ec->dev); 296 device_unregister(&ec->class_dev); 297 } 298 299 static const struct platform_device_id cros_ec_id[] = { 300 { DRV_NAME, 0 }, 301 { /* sentinel */ } 302 }; 303 MODULE_DEVICE_TABLE(platform, cros_ec_id); 304 305 static struct platform_driver cros_ec_dev_driver = { 306 .driver = { 307 .name = DRV_NAME, 308 }, 309 .id_table = cros_ec_id, 310 .probe = ec_device_probe, 311 .remove_new = ec_device_remove, 312 }; 313 314 static int __init cros_ec_dev_init(void) 315 { 316 int ret; 317 318 ret = class_register(&cros_class); 319 if (ret) { 320 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n"); 321 return ret; 322 } 323 324 /* Register the driver */ 325 ret = platform_driver_register(&cros_ec_dev_driver); 326 if (ret < 0) { 327 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret); 328 goto failed_devreg; 329 } 330 return 0; 331 332 failed_devreg: 333 class_unregister(&cros_class); 334 return ret; 335 } 336 337 static void __exit cros_ec_dev_exit(void) 338 { 339 platform_driver_unregister(&cros_ec_dev_driver); 340 class_unregister(&cros_class); 341 } 342 343 module_init(cros_ec_dev_init); 344 module_exit(cros_ec_dev_exit); 345 346 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>"); 347 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller"); 348 MODULE_VERSION("1.0"); 349 MODULE_LICENSE("GPL"); 350