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 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         ret = platform_driver_register(&cros_ec_dev_driver);
 363         if (ret) {
 364                 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
 365                 class_unregister(&cros_class);
 366         }
 367         return ret;
 368 }
 369
 370 static void __exit cros_ec_dev_exit(void)
 371 {
 372         platform_driver_unregister(&cros_ec_dev_driver);
 373         class_unregister(&cros_class);
 374 }
 375
 376 module_init(cros_ec_dev_init);
 377 module_exit(cros_ec_dev_exit);
 378
 379 MODULE_AUTHOR("Bill Richardson <[email protected]>");
 380 MODULE_DESCRIPTION("ChromeOS Embedded Controller");
 381 MODULE_VERSION("1.0");
 382 MODULE_LICENSE("GPL");