drivers/mfd/cros_ec_dev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * ChromeOS Embedded Controller
   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 mfd_cell cros_ec_ucsi_cells[] = {
 112         { .name = "cros_ec_ucsi", },
 113 };
 114
 115 static const struct cros_feature_to_cells cros_subdevices[] = {
 116         {
 117                 .id             = EC_FEATURE_CEC,
 118                 .mfd_cells      = cros_ec_cec_cells,
 119                 .num_cells      = ARRAY_SIZE(cros_ec_cec_cells),
 120         },
 121         {
 122                 .id             = EC_FEATURE_GPIO,
 123                 .mfd_cells      = cros_ec_gpio_cells,
 124                 .num_cells      = ARRAY_SIZE(cros_ec_gpio_cells),
 125         },
 126         {
 127                 .id             = EC_FEATURE_RTC,
 128                 .mfd_cells      = cros_ec_rtc_cells,
 129                 .num_cells      = ARRAY_SIZE(cros_ec_rtc_cells),
 130         },
 131         {
 132                 .id             = EC_FEATURE_UCSI_PPM,
 133                 .mfd_cells      = cros_ec_ucsi_cells,
 134                 .num_cells      = ARRAY_SIZE(cros_ec_ucsi_cells),
 135         },
 136         {
 137                 .id             = EC_FEATURE_HANG_DETECT,
 138                 .mfd_cells      = cros_ec_wdt_cells,
 139                 .num_cells      = ARRAY_SIZE(cros_ec_wdt_cells),
 140         },
 141         {
 142                 .id             = EC_FEATURE_LED,
 143                 .mfd_cells      = cros_ec_led_cells,
 144                 .num_cells      = ARRAY_SIZE(cros_ec_led_cells),
 145         },
 146         {
 147                 .id             = EC_FEATURE_PWM_KEYB,
 148                 .mfd_cells      = cros_ec_keyboard_leds_cells,
 149                 .num_cells      = ARRAY_SIZE(cros_ec_keyboard_leds_cells),
 150         },
 151 };
 152
 153 static const struct mfd_cell cros_ec_platform_cells[] = {
 154         { .name = "cros-ec-chardev", },
 155         { .name = "cros-ec-debugfs", },
 156         { .name = "cros-ec-hwmon", },
 157         { .name = "cros-ec-sysfs", },
 158 };
 159
 160 static const struct mfd_cell cros_ec_pchg_cells[] = {
 161         { .name = "cros-ec-pchg", },
 162 };
 163
 164 static const struct mfd_cell cros_ec_lightbar_cells[] = {
 165         { .name = "cros-ec-lightbar", }
 166 };
 167
 168 static const struct mfd_cell cros_ec_vbc_cells[] = {
 169         { .name = "cros-ec-vbc", }
 170 };
 171
 172 static void cros_ec_class_release(struct device *dev)
 173 {
 174         kfree(to_cros_ec_dev(dev));
 175 }
 176
 177 static int ec_device_probe(struct platform_device *pdev)
 178 {
 179         int retval = -ENOMEM;
 180         struct device_node *node;
 181         struct device *dev = &pdev->dev;
 182         struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
 183         struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
 184         struct ec_response_pchg_count pchg_count;
 185         int i;
 186
 187         if (!ec)
 188                 return retval;
 189
 190         dev_set_drvdata(dev, ec);
 191         ec->ec_dev = dev_get_drvdata(dev->parent);
 192         ec->dev = dev;
 193         ec->cmd_offset = ec_platform->cmd_offset;
 194         ec->features.flags[0] = -1U; /* Not cached yet */
 195         ec->features.flags[1] = -1U; /* Not cached yet */
 196         device_initialize(&ec->class_dev);
 197
 198         for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
 199                 /*
 200                  * Check whether this is actually a dedicated MCU rather
 201                  * than an standard EC.
 202                  */
 203                 if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
 204                         dev_info(dev, "CrOS %s MCU detected\n",
 205                                  cros_mcu_devices[i].desc);
 206                         /*
 207                          * Help userspace differentiating ECs from other MCU,
 208                          * regardless of the probing order.
 209                          */
 210                         ec_platform->ec_name = cros_mcu_devices[i].name;
 211                         break;
 212                 }
 213         }
 214
 215         /*
 216          * Add the class device
 217          */
 218         ec->class_dev.class = &cros_class;
 219         ec->class_dev.parent = dev;
 220         ec->class_dev.release = cros_ec_class_release;
 221
 222         retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
 223         if (retval) {
 224                 dev_err(dev, "dev_set_name failed => %d\n", retval);
 225                 goto failed;
 226         }
 227
 228         retval = device_add(&ec->class_dev);
 229         if (retval)
 230                 goto failed;
 231
 232         /* check whether this EC is a sensor hub. */
 233         if (cros_ec_get_sensor_count(ec) > 0) {
 234                 retval = mfd_add_hotplug_devices(ec->dev,
 235                                 cros_ec_sensorhub_cells,
 236                                 ARRAY_SIZE(cros_ec_sensorhub_cells));
 237                 if (retval)
 238                         dev_err(ec->dev, "failed to add %s subdevice: %d\n",
 239                                 cros_ec_sensorhub_cells->name, retval);
 240         }
 241
 242         /*
 243          * The following subdevices can be detected by sending the
 244          * EC_FEATURE_GET_CMD Embedded Controller device.
 245          */
 246         for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
 247                 if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
 248                         retval = mfd_add_hotplug_devices(ec->dev,
 249                                                 cros_subdevices[i].mfd_cells,
 250                                                 cros_subdevices[i].num_cells);
 251                         if (retval)
 252                                 dev_err(ec->dev,
 253                                         "failed to add %s subdevice: %d\n",
 254                                         cros_subdevices[i].mfd_cells->name,
 255                                         retval);
 256                 }
 257         }
 258
 259         /*
 260          * UCSI provides power supply information so we don't need to separately
 261          * load the cros_usbpd_charger driver.
 262          */
 263         if (cros_ec_check_features(ec, EC_FEATURE_USB_PD) &&
 264             !cros_ec_check_features(ec, EC_FEATURE_UCSI_PPM)) {
 265                 retval = mfd_add_hotplug_devices(ec->dev,
 266                                                  cros_usbpd_charger_cells,
 267                                                  ARRAY_SIZE(cros_usbpd_charger_cells));
 268
 269                 if (retval)
 270                         dev_warn(ec->dev, "failed to add usbpd-charger: %d\n",
 271                                  retval);
 272         }
 273
 274         /*
 275          * Lightbar is a special case. Newer devices support autodetection,
 276          * but older ones do not.
 277          */
 278         if (cros_ec_check_features(ec, EC_FEATURE_LIGHTBAR) ||
 279             dmi_match(DMI_PRODUCT_NAME, "Link")) {
 280                 retval = mfd_add_hotplug_devices(ec->dev,
 281                                         cros_ec_lightbar_cells,
 282                                         ARRAY_SIZE(cros_ec_lightbar_cells));
 283                 if (retval)
 284                         dev_warn(ec->dev, "failed to add lightbar: %d\n",
 285                                  retval);
 286         }
 287
 288         /*
 289          * The PD notifier driver cell is separate since it only needs to be
 290          * explicitly added on platforms that don't have the PD notifier ACPI
 291          * device entry defined.
 292          */
 293         if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) {
 294                 if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
 295                         retval = mfd_add_hotplug_devices(ec->dev,
 296                                         cros_usbpd_notify_cells,
 297                                         ARRAY_SIZE(cros_usbpd_notify_cells));
 298                         if (retval)
 299                                 dev_err(ec->dev,
 300                                         "failed to add PD notify devices: %d\n",
 301                                         retval);
 302                 }
 303         }
 304
 305         /*
 306          * The PCHG device cannot be detected by sending EC_FEATURE_GET_CMD, but
 307          * it can be detected by querying the number of peripheral chargers.
 308          */
 309         retval = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_PCHG_COUNT, NULL, 0,
 310                              &pchg_count, sizeof(pchg_count));
 311         if (retval >= 0 && pchg_count.port_count) {
 312                 retval = mfd_add_hotplug_devices(ec->dev,
 313                                         cros_ec_pchg_cells,
 314                                         ARRAY_SIZE(cros_ec_pchg_cells));
 315                 if (retval)
 316                         dev_warn(ec->dev, "failed to add pchg: %d\n",
 317                                  retval);
 318         }
 319
 320         /*
 321          * The following subdevices cannot be detected by sending the
 322          * EC_FEATURE_GET_CMD to the Embedded Controller device.
 323          */
 324         retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
 325                                          ARRAY_SIZE(cros_ec_platform_cells));
 326         if (retval)
 327                 dev_warn(ec->dev,
 328                          "failed to add cros-ec platform devices: %d\n",
 329                          retval);
 330
 331         /* Check whether this EC instance has a VBC NVRAM */
 332         node = ec->ec_dev->dev->of_node;
 333         if (of_property_read_bool(node, "google,has-vbc-nvram")) {
 334                 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
 335                                                 ARRAY_SIZE(cros_ec_vbc_cells));
 336                 if (retval)
 337                         dev_warn(ec->dev, "failed to add VBC devices: %d\n",
 338                                  retval);
 339         }
 340
 341         return 0;
 342
 343 failed:
 344         put_device(&ec->class_dev);
 345         return retval;
 346 }
 347
 348 static void ec_device_remove(struct platform_device *pdev)
 349 {
 350         struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
 351
 352         mfd_remove_devices(ec->dev);
 353         device_unregister(&ec->class_dev);
 354 }
 355
 356 static const struct platform_device_id cros_ec_id[] = {
 357         { DRV_NAME, 0 },
 358         { /* sentinel */ }
 359 };
 360 MODULE_DEVICE_TABLE(platform, cros_ec_id);
 361
 362 static struct platform_driver cros_ec_dev_driver = {
 363         .driver = {
 364                 .name = DRV_NAME,
 365         },
 366         .id_table = cros_ec_id,
 367         .probe = ec_device_probe,
 368         .remove = ec_device_remove,
 369 };
 370
 371 static int __init cros_ec_dev_init(void)
 372 {
 373         int ret;
 374
 375         ret = class_register(&cros_class);
 376         if (ret) {
 377                 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
 378                 return ret;
 379         }
 380
 381         ret = platform_driver_register(&cros_ec_dev_driver);
 382         if (ret) {
 383                 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
 384                 class_unregister(&cros_class);
 385         }
 386         return ret;
 387 }
 388
 389 static void __exit cros_ec_dev_exit(void)
 390 {
 391         platform_driver_unregister(&cros_ec_dev_driver);
 392         class_unregister(&cros_class);
 393 }
 394
 395 module_init(cros_ec_dev_init);
 396 module_exit(cros_ec_dev_exit);
 397
 398 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
 399 MODULE_DESCRIPTION("ChromeOS Embedded Controller");
 400 MODULE_VERSION("1.0");
 401 MODULE_LICENSE("GPL");