drivers/extcon/extcon-usbc-cros-ec.c

   1 /**
   2  * drivers/extcon/extcon-usbc-cros-ec - ChromeOS Embedded Controller extcon
   3  *
   4  * Copyright (C) 2017 Google, Inc
   5  * Author: Benson Leung <bleung@chromium.org>
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/extcon.h>
  18 #include <linux/kernel.h>
  19 #include <linux/mfd/cros_ec.h>
  20 #include <linux/module.h>
  21 #include <linux/notifier.h>
  22 #include <linux/of.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/slab.h>
  25 #include <linux/sched.h>
  26
  27 struct cros_ec_extcon_info {
  28         struct device *dev;
  29         struct extcon_dev *edev;
  30
  31         int port_id;
  32
  33         struct cros_ec_device *ec;
  34
  35         struct notifier_block notifier;
  36
  37         bool dp; /* DisplayPort enabled */
  38         bool mux; /* SuperSpeed (usb3) enabled */
  39         unsigned int power_type;
  40 };
  41
  42 static const unsigned int usb_type_c_cable[] = {
  43         EXTCON_DISP_DP,
  44         EXTCON_NONE,
  45 };
  46
  47 /**
  48  * cros_ec_pd_command() - Send a command to the EC.
  49  * @info: pointer to struct cros_ec_extcon_info
  50  * @command: EC command
  51  * @version: EC command version
  52  * @outdata: EC command output data
  53  * @outsize: Size of outdata
  54  * @indata: EC command input data
  55  * @insize: Size of indata
  56  *
  57  * Return: 0 on success, <0 on failure.
  58  */
  59 static int cros_ec_pd_command(struct cros_ec_extcon_info *info,
  60                               unsigned int command,
  61                               unsigned int version,
  62                               void *outdata,
  63                               unsigned int outsize,
  64                               void *indata,
  65                               unsigned int insize)
  66 {
  67         struct cros_ec_command *msg;
  68         int ret;
  69
  70         msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
  71         if (!msg)
  72                 return -ENOMEM;
  73
  74         msg->version = version;
  75         msg->command = command;
  76         msg->outsize = outsize;
  77         msg->insize = insize;
  78
  79         if (outsize)
  80                 memcpy(msg->data, outdata, outsize);
  81
  82         ret = cros_ec_cmd_xfer_status(info->ec, msg);
  83         if (ret >= 0 && insize)
  84                 memcpy(indata, msg->data, insize);
  85
  86         kfree(msg);
  87         return ret;
  88 }
  89
  90 /**
  91  * cros_ec_usb_get_power_type() - Get power type info about PD device attached
  92  * to given port.
  93  * @info: pointer to struct cros_ec_extcon_info
  94  *
  95  * Return: power type on success, <0 on failure.
  96  */
  97 static int cros_ec_usb_get_power_type(struct cros_ec_extcon_info *info)
  98 {
  99         struct ec_params_usb_pd_power_info req;
 100         struct ec_response_usb_pd_power_info resp;
 101         int ret;
 102
 103         req.port = info->port_id;
 104         ret = cros_ec_pd_command(info, EC_CMD_USB_PD_POWER_INFO, 0,
 105                                  &req, sizeof(req), &resp, sizeof(resp));
 106         if (ret < 0)
 107                 return ret;
 108
 109         return resp.type;
 110 }
 111
 112 /**
 113  * cros_ec_usb_get_pd_mux_state() - Get PD mux state for given port.
 114  * @info: pointer to struct cros_ec_extcon_info
 115  *
 116  * Return: PD mux state on success, <0 on failure.
 117  */
 118 static int cros_ec_usb_get_pd_mux_state(struct cros_ec_extcon_info *info)
 119 {
 120         struct ec_params_usb_pd_mux_info req;
 121         struct ec_response_usb_pd_mux_info resp;
 122         int ret;
 123
 124         req.port = info->port_id;
 125         ret = cros_ec_pd_command(info, EC_CMD_USB_PD_MUX_INFO, 0,
 126                                  &req, sizeof(req),
 127                                  &resp, sizeof(resp));
 128         if (ret < 0)
 129                 return ret;
 130
 131         return resp.flags;
 132 }
 133
 134 /**
 135  * cros_ec_usb_get_role() - Get role info about possible PD device attached to a
 136  * given port.
 137  * @info: pointer to struct cros_ec_extcon_info
 138  * @polarity: pointer to cable polarity (return value)
 139  *
 140  * Return: role info on success, -ENOTCONN if no cable is connected, <0 on
 141  * failure.
 142  */
 143 static int cros_ec_usb_get_role(struct cros_ec_extcon_info *info,
 144                                 bool *polarity)
 145 {
 146         struct ec_params_usb_pd_control pd_control;
 147         struct ec_response_usb_pd_control_v1 resp;
 148         int ret;
 149
 150         pd_control.port = info->port_id;
 151         pd_control.role = USB_PD_CTRL_ROLE_NO_CHANGE;
 152         pd_control.mux = USB_PD_CTRL_MUX_NO_CHANGE;
 153         ret = cros_ec_pd_command(info, EC_CMD_USB_PD_CONTROL, 1,
 154                                  &pd_control, sizeof(pd_control),
 155                                  &resp, sizeof(resp));
 156         if (ret < 0)
 157                 return ret;
 158
 159         if (!(resp.enabled & PD_CTRL_RESP_ENABLED_CONNECTED))
 160                 return -ENOTCONN;
 161
 162         *polarity = resp.polarity;
 163
 164         return resp.role;
 165 }
 166
 167 /**
 168  * cros_ec_pd_get_num_ports() - Get number of EC charge ports.
 169  * @info: pointer to struct cros_ec_extcon_info
 170  *
 171  * Return: number of ports on success, <0 on failure.
 172  */
 173 static int cros_ec_pd_get_num_ports(struct cros_ec_extcon_info *info)
 174 {
 175         struct ec_response_usb_pd_ports resp;
 176         int ret;
 177
 178         ret = cros_ec_pd_command(info, EC_CMD_USB_PD_PORTS,
 179                                  0, NULL, 0, &resp, sizeof(resp));
 180         if (ret < 0)
 181                 return ret;
 182
 183         return resp.num_ports;
 184 }
 185
 186 static int extcon_cros_ec_detect_cable(struct cros_ec_extcon_info *info,
 187                                        bool force)
 188 {
 189         struct device *dev = info->dev;
 190         int role, power_type;
 191         bool polarity = false;
 192         bool dp = false;
 193         bool mux = false;
 194         bool hpd = false;
 195
 196         power_type = cros_ec_usb_get_power_type(info);
 197         if (power_type < 0) {
 198                 dev_err(dev, "failed getting power type err = %d\n",
 199                         power_type);
 200                 return power_type;
 201         }
 202
 203         role = cros_ec_usb_get_role(info, &polarity);
 204         if (role < 0) {
 205                 if (role != -ENOTCONN) {
 206                         dev_err(dev, "failed getting role err = %d\n", role);
 207                         return role;
 208                 }
 209         } else {
 210                 int pd_mux_state;
 211
 212                 pd_mux_state = cros_ec_usb_get_pd_mux_state(info);
 213                 if (pd_mux_state < 0)
 214                         pd_mux_state = USB_PD_MUX_USB_ENABLED;
 215
 216                 dp = pd_mux_state & USB_PD_MUX_DP_ENABLED;
 217                 mux = pd_mux_state & USB_PD_MUX_USB_ENABLED;
 218                 hpd = pd_mux_state & USB_PD_MUX_HPD_IRQ;
 219         }
 220
 221         if (force || info->dp != dp || info->mux != mux ||
 222                 info->power_type != power_type) {
 223
 224                 info->dp = dp;
 225                 info->mux = mux;
 226                 info->power_type = power_type;
 227
 228                 extcon_set_state(info->edev, EXTCON_DISP_DP, dp);
 229
 230                 extcon_set_property(info->edev, EXTCON_DISP_DP,
 231                                     EXTCON_PROP_USB_TYPEC_POLARITY,
 232                                     (union extcon_property_value)(int)polarity);
 233                 extcon_set_property(info->edev, EXTCON_DISP_DP,
 234                                     EXTCON_PROP_USB_SS,
 235                                     (union extcon_property_value)(int)mux);
 236                 extcon_set_property(info->edev, EXTCON_DISP_DP,
 237                                     EXTCON_PROP_DISP_HPD,
 238                                     (union extcon_property_value)(int)hpd);
 239
 240                 extcon_sync(info->edev, EXTCON_DISP_DP);
 241
 242         } else if (hpd) {
 243                 extcon_set_property(info->edev, EXTCON_DISP_DP,
 244                                     EXTCON_PROP_DISP_HPD,
 245                                     (union extcon_property_value)(int)hpd);
 246                 extcon_sync(info->edev, EXTCON_DISP_DP);
 247         }
 248
 249         return 0;
 250 }
 251
 252 static int extcon_cros_ec_event(struct notifier_block *nb,
 253                                 unsigned long queued_during_suspend,
 254                                 void *_notify)
 255 {
 256         struct cros_ec_extcon_info *info;
 257         struct cros_ec_device *ec;
 258         u32 host_event;
 259
 260         info = container_of(nb, struct cros_ec_extcon_info, notifier);
 261         ec = info->ec;
 262
 263         host_event = cros_ec_get_host_event(ec);
 264         if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
 265                           EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
 266                 extcon_cros_ec_detect_cable(info, false);
 267                 return NOTIFY_OK;
 268         }
 269
 270         return NOTIFY_DONE;
 271 }
 272
 273 static int extcon_cros_ec_probe(struct platform_device *pdev)
 274 {
 275         struct cros_ec_extcon_info *info;
 276         struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
 277         struct device *dev = &pdev->dev;
 278         struct device_node *np = dev->of_node;
 279         int numports, ret;
 280
 281         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 282         if (!info)
 283                 return -ENOMEM;
 284
 285         info->dev = dev;
 286         info->ec = ec;
 287
 288         if (np) {
 289                 u32 port;
 290
 291                 ret = of_property_read_u32(np, "google,usb-port-id", &port);
 292                 if (ret < 0) {
 293                         dev_err(dev, "Missing google,usb-port-id property\n");
 294                         return ret;
 295                 }
 296                 info->port_id = port;
 297         } else {
 298                 info->port_id = pdev->id;
 299         }
 300
 301         numports = cros_ec_pd_get_num_ports(info);
 302         if (numports < 0) {
 303                 dev_err(dev, "failed getting number of ports! ret = %d\n",
 304                         numports);
 305                 return numports;
 306         }
 307
 308         if (info->port_id >= numports) {
 309                 dev_err(dev, "This system only supports %d ports\n", numports);
 310                 return -ENODEV;
 311         }
 312
 313         info->edev = devm_extcon_dev_allocate(dev, usb_type_c_cable);
 314         if (IS_ERR(info->edev)) {
 315                 dev_err(dev, "failed to allocate extcon device\n");
 316                 return -ENOMEM;
 317         }
 318
 319         ret = devm_extcon_dev_register(dev, info->edev);
 320         if (ret < 0) {
 321                 dev_err(dev, "failed to register extcon device\n");
 322                 return ret;
 323         }
 324
 325         extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
 326                                        EXTCON_PROP_USB_TYPEC_POLARITY);
 327         extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
 328                                        EXTCON_PROP_USB_SS);
 329         extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
 330                                        EXTCON_PROP_DISP_HPD);
 331
 332         platform_set_drvdata(pdev, info);
 333
 334         /* Get PD events from the EC */
 335         info->notifier.notifier_call = extcon_cros_ec_event;
 336         ret = blocking_notifier_chain_register(&info->ec->event_notifier,
 337                                                &info->notifier);
 338         if (ret < 0) {
 339                 dev_err(dev, "failed to register notifier\n");
 340                 return ret;
 341         }
 342
 343         /* Perform initial detection */
 344         ret = extcon_cros_ec_detect_cable(info, true);
 345         if (ret < 0) {
 346                 dev_err(dev, "failed to detect initial cable state\n");
 347                 goto unregister_notifier;
 348         }
 349
 350         return 0;
 351
 352 unregister_notifier:
 353         blocking_notifier_chain_unregister(&info->ec->event_notifier,
 354                                            &info->notifier);
 355         return ret;
 356 }
 357
 358 static int extcon_cros_ec_remove(struct platform_device *pdev)
 359 {
 360         struct cros_ec_extcon_info *info = platform_get_drvdata(pdev);
 361
 362         blocking_notifier_chain_unregister(&info->ec->event_notifier,
 363                                            &info->notifier);
 364
 365         return 0;
 366 }
 367
 368 #ifdef CONFIG_PM_SLEEP
 369 static int extcon_cros_ec_suspend(struct device *dev)
 370 {
 371         return 0;
 372 }
 373
 374 static int extcon_cros_ec_resume(struct device *dev)
 375 {
 376         int ret;
 377         struct cros_ec_extcon_info *info = dev_get_drvdata(dev);
 378
 379         ret = extcon_cros_ec_detect_cable(info, true);
 380         if (ret < 0)
 381                 dev_err(dev, "failed to detect cable state on resume\n");
 382
 383         return 0;
 384 }
 385
 386 static const struct dev_pm_ops extcon_cros_ec_dev_pm_ops = {
 387         SET_SYSTEM_SLEEP_PM_OPS(extcon_cros_ec_suspend, extcon_cros_ec_resume)
 388 };
 389
 390 #define DEV_PM_OPS      (&extcon_cros_ec_dev_pm_ops)
 391 #else
 392 #define DEV_PM_OPS      NULL
 393 #endif /* CONFIG_PM_SLEEP */
 394
 395 #ifdef CONFIG_OF
 396 static const struct of_device_id extcon_cros_ec_of_match[] = {
 397         { .compatible = "google,extcon-usbc-cros-ec" },
 398         { /* sentinel */ }
 399 };
 400 MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
 401 #endif /* CONFIG_OF */
 402
 403 static struct platform_driver extcon_cros_ec_driver = {
 404         .driver = {
 405                 .name  = "extcon-usbc-cros-ec",
 406                 .of_match_table = of_match_ptr(extcon_cros_ec_of_match),
 407                 .pm = DEV_PM_OPS,
 408         },
 409         .remove  = extcon_cros_ec_remove,
 410         .probe   = extcon_cros_ec_probe,
 411 };
 412
 413 module_platform_driver(extcon_cros_ec_driver);
 414
 415 MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
 416 MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
 417 MODULE_LICENSE("GPL");