drivers/staging/typec/tcpci.c

   1 /*
   2  * Copyright 2015-2017 Google, Inc
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * USB Type-C Port Controller Interface.
  15  */
  16
  17 #include <linux/delay.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/i2c.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/regmap.h>
  23 #include <linux/usb/typec.h>
  24
  25 #include "pd.h"
  26 #include "tcpci.h"
  27 #include "tcpm.h"
  28
  29 #define PD_RETRY_COUNT 3
  30
  31 #define tcpc_presenting_cc1_rd(reg) \
  32         (!(TCPC_ROLE_CTRL_DRP & (reg)) && \
  33          (((reg) & (TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT)) == \
  34           (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC1_SHIFT)))
  35 #define tcpc_presenting_cc2_rd(reg) \
  36         (!(TCPC_ROLE_CTRL_DRP & (reg)) && \
  37          (((reg) & (TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT)) == \
  38           (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC2_SHIFT)))
  39
  40 struct tcpci {
  41         struct device *dev;
  42         struct i2c_client *client;
  43
  44         struct tcpm_port *port;
  45
  46         struct regmap *regmap;
  47
  48         bool controls_vbus;
  49
  50         struct tcpc_dev tcpc;
  51 };
  52
  53 static inline struct tcpci *tcpc_to_tcpci(struct tcpc_dev *tcpc)
  54 {
  55         return container_of(tcpc, struct tcpci, tcpc);
  56 }
  57
  58 static int tcpci_read16(struct tcpci *tcpci, unsigned int reg,
  59                         unsigned int *val)
  60 {
  61         return regmap_raw_read(tcpci->regmap, reg, val, sizeof(u16));
  62 }
  63
  64 static int tcpci_write16(struct tcpci *tcpci, unsigned int reg, u16 val)
  65 {
  66         return regmap_raw_write(tcpci->regmap, reg, &val, sizeof(u16));
  67 }
  68
  69 static int tcpci_set_cc(struct tcpc_dev *tcpc, enum typec_cc_status cc)
  70 {
  71         struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  72         unsigned int reg;
  73         int ret;
  74
  75         switch (cc) {
  76         case TYPEC_CC_RA:
  77                 reg = (TCPC_ROLE_CTRL_CC_RA << TCPC_ROLE_CTRL_CC1_SHIFT) |
  78                         (TCPC_ROLE_CTRL_CC_RA << TCPC_ROLE_CTRL_CC2_SHIFT);
  79                 break;
  80         case TYPEC_CC_RD:
  81                 reg = (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC1_SHIFT) |
  82                         (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC2_SHIFT);
  83                 break;
  84         case TYPEC_CC_RP_DEF:
  85                 reg = (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT) |
  86                         (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT) |
  87                         (TCPC_ROLE_CTRL_RP_VAL_DEF <<
  88                          TCPC_ROLE_CTRL_RP_VAL_SHIFT);
  89                 break;
  90         case TYPEC_CC_RP_1_5:
  91                 reg = (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT) |
  92                         (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT) |
  93                         (TCPC_ROLE_CTRL_RP_VAL_1_5 <<
  94                          TCPC_ROLE_CTRL_RP_VAL_SHIFT);
  95                 break;
  96         case TYPEC_CC_RP_3_0:
  97                 reg = (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT) |
  98                         (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT) |
  99                         (TCPC_ROLE_CTRL_RP_VAL_3_0 <<
 100                          TCPC_ROLE_CTRL_RP_VAL_SHIFT);
 101                 break;
 102         case TYPEC_CC_OPEN:
 103         default:
 104                 reg = (TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC1_SHIFT) |
 105                         (TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC2_SHIFT);
 106                 break;
 107         }
 108
 109         ret = regmap_write(tcpci->regmap, TCPC_ROLE_CTRL, reg);
 110         if (ret < 0)
 111                 return ret;
 112
 113         return 0;
 114 }
 115
 116 static int tcpci_start_drp_toggling(struct tcpc_dev *tcpc,
 117                                     enum typec_cc_status cc)
 118 {
 119         struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
 120         unsigned int reg = TCPC_ROLE_CTRL_DRP;
 121
 122         switch (cc) {
 123         default:
 124         case TYPEC_CC_RP_DEF:
 125                 reg |= (TCPC_ROLE_CTRL_RP_VAL_DEF <<
 126                         TCPC_ROLE_CTRL_RP_VAL_SHIFT);
 127                 break;
 128         case TYPEC_CC_RP_1_5:
 129                 reg |= (TCPC_ROLE_CTRL_RP_VAL_1_5 <<
 130                         TCPC_ROLE_CTRL_RP_VAL_SHIFT);
 131                 break;
 132         case TYPEC_CC_RP_3_0:
 133                 reg |= (TCPC_ROLE_CTRL_RP_VAL_3_0 <<
 134                         TCPC_ROLE_CTRL_RP_VAL_SHIFT);
 135                 break;
 136         }
 137
 138         return regmap_write(tcpci->regmap, TCPC_ROLE_CTRL, reg);
 139 }
 140
 141 static enum typec_cc_status tcpci_to_typec_cc(unsigned int cc, bool sink)
 142 {
 143         switch (cc) {
 144         case 0x1:
 145                 return sink ? TYPEC_CC_RP_DEF : TYPEC_CC_RA;
 146         case 0x2:
 147                 return sink ? TYPEC_CC_RP_1_5 : TYPEC_CC_RD;
 148         case 0x3:
 149                 if (sink)
 150                         return TYPEC_CC_RP_3_0;
 151         case 0x0:
 152         default:
 153                 return TYPEC_CC_OPEN;
 154         }
 155 }
 156
 157 static int tcpci_get_cc(struct tcpc_dev *tcpc,
 158                         enum typec_cc_status *cc1, enum typec_cc_status *cc2)
 159 {
 160         struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
 161         unsigned int reg, role_control;
 162         int ret;
 163
 164         ret = regmap_read(tcpci->regmap, TCPC_ROLE_CTRL, &role_control);
 165         if (ret < 0)
 166                 return ret;
 167
 168         ret = regmap_read(tcpci->regmap, TCPC_CC_STATUS, &reg);
 169         if (ret < 0)
 170                 return ret;
 171
 172         *cc1 = tcpci_to_typec_cc((reg >> TCPC_CC_STATUS_CC1_SHIFT) &
 173                                  TCPC_CC_STATUS_CC1_MASK,
 174                                  reg & TCPC_CC_STATUS_TERM ||
 175                                  tcpc_presenting_cc1_rd(role_control));
 176         *cc2 = tcpci_to_typec_cc((reg >> TCPC_CC_STATUS_CC2_SHIFT) &
 177                                  TCPC_CC_STATUS_CC2_MASK,
 178                                  reg & TCPC_CC_STATUS_TERM ||
 179                                  tcpc_presenting_cc2_rd(role_control));
 180
 181         return 0;
 182 }
 183
 184 static int tcpci_set_polarity(struct tcpc_dev *tcpc,
 185                               enum typec_cc_polarity polarity)
 186 {
 187         struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
 188         int ret;
 189
 190         ret = regmap_write(tcpci->regmap, TCPC_TCPC_CTRL,
 191                            (polarity == TYPEC_POLARITY_CC2) ?
 192                            TCPC_TCPC_CTRL_ORIENTATION : 0);
 193         if (ret < 0)
 194                 return ret;
 195
 196         return 0;
 197 }
 198
 199 static int tcpci_set_vconn(struct tcpc_dev *tcpc, bool enable)
 200 {
 201         struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
 202         int ret;
 203
 204         ret = regmap_write(tcpci->regmap, TCPC_POWER_CTRL,
 205                            enable ? TCPC_POWER_CTRL_VCONN_ENABLE : 0);
 206         if (ret < 0)
 207                 return ret;
 208
 209         return 0;
 210 }
 211
 212 static int tcpci_set_roles(struct tcpc_dev *tcpc, bool attached,
 213                            enum typec_role role, enum typec_data_role data)
 214 {
 215         struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
 216         unsigned int reg;
 217         int ret;
 218
 219         reg = PD_REV20 << TCPC_MSG_HDR_INFO_REV_SHIFT;
 220         if (role == TYPEC_SOURCE)
 221                 reg |= TCPC_MSG_HDR_INFO_PWR_ROLE;
 222         if (data == TYPEC_HOST)
 223                 reg |= TCPC_MSG_HDR_INFO_DATA_ROLE;
 224         ret = regmap_write(tcpci->regmap, TCPC_MSG_HDR_INFO, reg);
 225         if (ret < 0)
 226                 return ret;
 227
 228         return 0;
 229 }
 230
 231 static int tcpci_set_pd_rx(struct tcpc_dev *tcpc, bool enable)
 232 {
 233         struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
 234         unsigned int reg = 0;
 235         int ret;
 236
 237         if (enable)
 238                 reg = TCPC_RX_DETECT_SOP | TCPC_RX_DETECT_HARD_RESET;
 239         ret = regmap_write(tcpci->regmap, TCPC_RX_DETECT, reg);
 240         if (ret < 0)
 241                 return ret;
 242
 243         return 0;
 244 }
 245
 246 static int tcpci_get_vbus(struct tcpc_dev *tcpc)
 247 {
 248         struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
 249         unsigned int reg;
 250         int ret;
 251
 252         ret = regmap_read(tcpci->regmap, TCPC_POWER_STATUS, &reg);
 253         if (ret < 0)
 254                 return ret;
 255
 256         return !!(reg & TCPC_POWER_STATUS_VBUS_PRES);
 257 }
 258
 259 static int tcpci_set_vbus(struct tcpc_dev *tcpc, bool source, bool sink)
 260 {
 261         struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
 262         int ret;
 263
 264         /* Disable both source and sink first before enabling anything */
 265
 266         if (!source) {
 267                 ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
 268                                    TCPC_CMD_DISABLE_SRC_VBUS);
 269                 if (ret < 0)
 270                         return ret;
 271         }
 272
 273         if (!sink) {
 274                 ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
 275                                    TCPC_CMD_DISABLE_SINK_VBUS);
 276                 if (ret < 0)
 277                         return ret;
 278         }
 279
 280         if (source) {
 281                 ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
 282                                    TCPC_CMD_SRC_VBUS_DEFAULT);
 283                 if (ret < 0)
 284                         return ret;
 285         }
 286
 287         if (sink) {
 288                 ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
 289                                    TCPC_CMD_SINK_VBUS);
 290                 if (ret < 0)
 291                         return ret;
 292         }
 293
 294         return 0;
 295 }
 296
 297 static int tcpci_pd_transmit(struct tcpc_dev *tcpc,
 298                              enum tcpm_transmit_type type,
 299                              const struct pd_message *msg)
 300 {
 301         struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
 302         unsigned int reg, cnt, header;
 303         int ret;
 304
 305         cnt = msg ? pd_header_cnt(msg->header) * 4 : 0;
 306         ret = regmap_write(tcpci->regmap, TCPC_TX_BYTE_CNT, cnt + 2);
 307         if (ret < 0)
 308                 return ret;
 309
 310         header = msg ? msg->header : 0;
 311         ret = tcpci_write16(tcpci, TCPC_TX_HDR, header);
 312         if (ret < 0)
 313                 return ret;
 314
 315         if (cnt > 0) {
 316                 ret = regmap_raw_write(tcpci->regmap, TCPC_TX_DATA,
 317                                        &msg->payload, cnt);
 318                 if (ret < 0)
 319                         return ret;
 320         }
 321
 322         reg = (PD_RETRY_COUNT << TCPC_TRANSMIT_RETRY_SHIFT) |
 323                 (type << TCPC_TRANSMIT_TYPE_SHIFT);
 324         ret = regmap_write(tcpci->regmap, TCPC_TRANSMIT, reg);
 325         if (ret < 0)
 326                 return ret;
 327
 328         return 0;
 329 }
 330
 331 static int tcpci_init(struct tcpc_dev *tcpc)
 332 {
 333         struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
 334         unsigned long timeout = jiffies + msecs_to_jiffies(2000); /* XXX */
 335         unsigned int reg;
 336         int ret;
 337
 338         while (time_before_eq(jiffies, timeout)) {
 339                 ret = regmap_read(tcpci->regmap, TCPC_POWER_STATUS, &reg);
 340                 if (ret < 0)
 341                         return ret;
 342                 if (!(reg & TCPC_POWER_STATUS_UNINIT))
 343                         break;
 344                 usleep_range(10000, 20000);
 345         }
 346         if (time_after(jiffies, timeout))
 347                 return -ETIMEDOUT;
 348
 349         /* Clear all events */
 350         ret = tcpci_write16(tcpci, TCPC_ALERT, 0xffff);
 351         if (ret < 0)
 352                 return ret;
 353
 354         if (tcpci->controls_vbus)
 355                 reg = TCPC_POWER_STATUS_VBUS_PRES;
 356         else
 357                 reg = 0;
 358         ret = regmap_write(tcpci->regmap, TCPC_POWER_STATUS_MASK, reg);
 359         if (ret < 0)
 360                 return ret;
 361
 362         reg = TCPC_ALERT_TX_SUCCESS | TCPC_ALERT_TX_FAILED |
 363                 TCPC_ALERT_TX_DISCARDED | TCPC_ALERT_RX_STATUS |
 364                 TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS;
 365         if (tcpci->controls_vbus)
 366                 reg |= TCPC_ALERT_POWER_STATUS;
 367         return tcpci_write16(tcpci, TCPC_ALERT_MASK, reg);
 368 }
 369
 370 static irqreturn_t tcpci_irq(int irq, void *dev_id)
 371 {
 372         struct tcpci *tcpci = dev_id;
 373         unsigned int status, reg;
 374
 375         tcpci_read16(tcpci, TCPC_ALERT, &status);
 376
 377         /*
 378          * Clear alert status for everything except RX_STATUS, which shouldn't
 379          * be cleared until we have successfully retrieved message.
 380          */
 381         if (status & ~TCPC_ALERT_RX_STATUS)
 382                 tcpci_write16(tcpci, TCPC_ALERT,
 383                               status & ~TCPC_ALERT_RX_STATUS);
 384
 385         if (status & TCPC_ALERT_CC_STATUS)
 386                 tcpm_cc_change(tcpci->port);
 387
 388         if (status & TCPC_ALERT_POWER_STATUS) {
 389                 regmap_read(tcpci->regmap, TCPC_POWER_STATUS_MASK, &reg);
 390
 391                 /*
 392                  * If power status mask has been reset, then the TCPC
 393                  * has reset.
 394                  */
 395                 if (reg == 0xff)
 396                         tcpm_tcpc_reset(tcpci->port);
 397                 else
 398                         tcpm_vbus_change(tcpci->port);
 399         }
 400
 401         if (status & TCPC_ALERT_RX_STATUS) {
 402                 struct pd_message msg;
 403                 unsigned int cnt;
 404
 405                 regmap_read(tcpci->regmap, TCPC_RX_BYTE_CNT, &cnt);
 406
 407                 tcpci_read16(tcpci, TCPC_RX_HDR, &reg);
 408                 msg.header = reg;
 409
 410                 if (WARN_ON(cnt > sizeof(msg.payload)))
 411                         cnt = sizeof(msg.payload);
 412
 413                 if (cnt > 0)
 414                         regmap_raw_read(tcpci->regmap, TCPC_RX_DATA,
 415                                         &msg.payload, cnt);
 416
 417                 /* Read complete, clear RX status alert bit */
 418                 tcpci_write16(tcpci, TCPC_ALERT, TCPC_ALERT_RX_STATUS);
 419
 420                 tcpm_pd_receive(tcpci->port, &msg);
 421         }
 422
 423         if (status & TCPC_ALERT_RX_HARD_RST)
 424                 tcpm_pd_hard_reset(tcpci->port);
 425
 426         if (status & TCPC_ALERT_TX_SUCCESS)
 427                 tcpm_pd_transmit_complete(tcpci->port, TCPC_TX_SUCCESS);
 428         else if (status & TCPC_ALERT_TX_DISCARDED)
 429                 tcpm_pd_transmit_complete(tcpci->port, TCPC_TX_DISCARDED);
 430         else if (status & TCPC_ALERT_TX_FAILED)
 431                 tcpm_pd_transmit_complete(tcpci->port, TCPC_TX_FAILED);
 432
 433         return IRQ_HANDLED;
 434 }
 435
 436 static const struct regmap_config tcpci_regmap_config = {
 437         .reg_bits = 8,
 438         .val_bits = 8,
 439
 440         .max_register = 0x7F, /* 0x80 .. 0xFF are vendor defined */
 441 };
 442
 443 static const struct tcpc_config tcpci_tcpc_config = {
 444         .type = TYPEC_PORT_DFP,
 445         .default_role = TYPEC_SINK,
 446 };
 447
 448 static int tcpci_parse_config(struct tcpci *tcpci)
 449 {
 450         tcpci->controls_vbus = true; /* XXX */
 451
 452         /* TODO: Populate struct tcpc_config from ACPI/device-tree */
 453         tcpci->tcpc.config = &tcpci_tcpc_config;
 454
 455         return 0;
 456 }
 457
 458 static int tcpci_probe(struct i2c_client *client,
 459                        const struct i2c_device_id *i2c_id)
 460 {
 461         struct tcpci *tcpci;
 462         int err;
 463
 464         tcpci = devm_kzalloc(&client->dev, sizeof(*tcpci), GFP_KERNEL);
 465         if (!tcpci)
 466                 return -ENOMEM;
 467
 468         tcpci->client = client;
 469         tcpci->dev = &client->dev;
 470         i2c_set_clientdata(client, tcpci);
 471         tcpci->regmap = devm_regmap_init_i2c(client, &tcpci_regmap_config);
 472         if (IS_ERR(tcpci->regmap))
 473                 return PTR_ERR(tcpci->regmap);
 474
 475         tcpci->tcpc.init = tcpci_init;
 476         tcpci->tcpc.get_vbus = tcpci_get_vbus;
 477         tcpci->tcpc.set_vbus = tcpci_set_vbus;
 478         tcpci->tcpc.set_cc = tcpci_set_cc;
 479         tcpci->tcpc.get_cc = tcpci_get_cc;
 480         tcpci->tcpc.set_polarity = tcpci_set_polarity;
 481         tcpci->tcpc.set_vconn = tcpci_set_vconn;
 482         tcpci->tcpc.start_drp_toggling = tcpci_start_drp_toggling;
 483
 484         tcpci->tcpc.set_pd_rx = tcpci_set_pd_rx;
 485         tcpci->tcpc.set_roles = tcpci_set_roles;
 486         tcpci->tcpc.pd_transmit = tcpci_pd_transmit;
 487
 488         err = tcpci_parse_config(tcpci);
 489         if (err < 0)
 490                 return err;
 491
 492         /* Disable chip interrupts */
 493         tcpci_write16(tcpci, TCPC_ALERT_MASK, 0);
 494
 495         err = devm_request_threaded_irq(tcpci->dev, client->irq, NULL,
 496                                         tcpci_irq,
 497                                         IRQF_ONESHOT | IRQF_TRIGGER_LOW,
 498                                         dev_name(tcpci->dev), tcpci);
 499         if (err < 0)
 500                 return err;
 501
 502         tcpci->port = tcpm_register_port(tcpci->dev, &tcpci->tcpc);
 503         return PTR_ERR_OR_ZERO(tcpci->port);
 504 }
 505
 506 static int tcpci_remove(struct i2c_client *client)
 507 {
 508         struct tcpci *tcpci = i2c_get_clientdata(client);
 509
 510         tcpm_unregister_port(tcpci->port);
 511
 512         return 0;
 513 }
 514
 515 static const struct i2c_device_id tcpci_id[] = {
 516         { "tcpci", 0 },
 517         { }
 518 };
 519 MODULE_DEVICE_TABLE(i2c, tcpci_id);
 520
 521 #ifdef CONFIG_OF
 522 static const struct of_device_id tcpci_of_match[] = {
 523         { .compatible = "usb,tcpci", },
 524         {},
 525 };
 526 MODULE_DEVICE_TABLE(of, tcpci_of_match);
 527 #endif
 528
 529 static struct i2c_driver tcpci_i2c_driver = {
 530         .driver = {
 531                 .name = "tcpci",
 532                 .of_match_table = of_match_ptr(tcpci_of_match),
 533         },
 534         .probe = tcpci_probe,
 535         .remove = tcpci_remove,
 536         .id_table = tcpci_id,
 537 };
 538 module_i2c_driver(tcpci_i2c_driver);
 539
 540 MODULE_DESCRIPTION("USB Type-C Port Controller Interface driver");
 541 MODULE_LICENSE("GPL");