linux/drivers/usb/typec/tcpm/tcpci_maxim.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2020, Google LLC
   4 *
   5 * MAXIM TCPCI based TCPC driver
   6 */
   7
   8#include <linux/interrupt.h>
   9#include <linux/i2c.h>
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/regmap.h>
  13#include <linux/usb/pd.h>
  14#include <linux/usb/tcpm.h>
  15#include <linux/usb/typec.h>
  16
  17#include "tcpci.h"
  18
  19#define PD_ACTIVITY_TIMEOUT_MS                          10000
  20
  21#define TCPC_VENDOR_ALERT                               0x80
  22#define TCPC_VENDOR_USBSW_CTRL                          0x93
  23#define TCPC_VENDOR_USBSW_CTRL_ENABLE_USB_DATA          0x9
  24#define TCPC_VENDOR_USBSW_CTRL_DISABLE_USB_DATA         0
  25
  26#define TCPC_RECEIVE_BUFFER_COUNT_OFFSET                0
  27#define TCPC_RECEIVE_BUFFER_FRAME_TYPE_OFFSET           1
  28#define TCPC_RECEIVE_BUFFER_RX_BYTE_BUF_OFFSET          2
  29
  30/*
  31 * LongMessage not supported, hence 32 bytes for buf to be read from RECEIVE_BUFFER.
  32 * DEVICE_CAPABILITIES_2.LongMessage = 0, the value in READABLE_BYTE_COUNT reg shall be
  33 * less than or equal to 31. Since, RECEIVE_BUFFER len = 31 + 1(READABLE_BYTE_COUNT).
  34 */
  35#define TCPC_RECEIVE_BUFFER_LEN                         32
  36
  37#define MAX_BUCK_BOOST_SID                              0x69
  38#define MAX_BUCK_BOOST_OP                               0xb9
  39#define MAX_BUCK_BOOST_OFF                              0
  40#define MAX_BUCK_BOOST_SOURCE                           0xa
  41#define MAX_BUCK_BOOST_SINK                             0x5
  42
  43struct max_tcpci_chip {
  44        struct tcpci_data data;
  45        struct tcpci *tcpci;
  46        struct device *dev;
  47        struct i2c_client *client;
  48        struct tcpm_port *port;
  49};
  50
  51static const struct regmap_range max_tcpci_tcpci_range[] = {
  52        regmap_reg_range(0x00, 0x95)
  53};
  54
  55static const struct regmap_access_table max_tcpci_tcpci_write_table = {
  56        .yes_ranges = max_tcpci_tcpci_range,
  57        .n_yes_ranges = ARRAY_SIZE(max_tcpci_tcpci_range),
  58};
  59
  60static const struct regmap_config max_tcpci_regmap_config = {
  61        .reg_bits = 8,
  62        .val_bits = 8,
  63        .max_register = 0x95,
  64        .wr_table = &max_tcpci_tcpci_write_table,
  65};
  66
  67static struct max_tcpci_chip *tdata_to_max_tcpci(struct tcpci_data *tdata)
  68{
  69        return container_of(tdata, struct max_tcpci_chip, data);
  70}
  71
  72static int max_tcpci_read16(struct max_tcpci_chip *chip, unsigned int reg, u16 *val)
  73{
  74        return regmap_raw_read(chip->data.regmap, reg, val, sizeof(u16));
  75}
  76
  77static int max_tcpci_write16(struct max_tcpci_chip *chip, unsigned int reg, u16 val)
  78{
  79        return regmap_raw_write(chip->data.regmap, reg, &val, sizeof(u16));
  80}
  81
  82static int max_tcpci_read8(struct max_tcpci_chip *chip, unsigned int reg, u8 *val)
  83{
  84        return regmap_raw_read(chip->data.regmap, reg, val, sizeof(u8));
  85}
  86
  87static int max_tcpci_write8(struct max_tcpci_chip *chip, unsigned int reg, u8 val)
  88{
  89        return regmap_raw_write(chip->data.regmap, reg, &val, sizeof(u8));
  90}
  91
  92static void max_tcpci_init_regs(struct max_tcpci_chip *chip)
  93{
  94        u16 alert_mask = 0;
  95        int ret;
  96
  97        ret = max_tcpci_write16(chip, TCPC_ALERT, 0xffff);
  98        if (ret < 0) {
  99                dev_err(chip->dev, "Error writing to TCPC_ALERT ret:%d\n", ret);
 100                return;
 101        }
 102
 103        ret = max_tcpci_write16(chip, TCPC_VENDOR_ALERT, 0xffff);
 104        if (ret < 0) {
 105                dev_err(chip->dev, "Error writing to TCPC_VENDOR_ALERT ret:%d\n", ret);
 106                return;
 107        }
 108
 109        ret = max_tcpci_write8(chip, TCPC_ALERT_EXTENDED, 0xff);
 110        if (ret < 0) {
 111                dev_err(chip->dev, "Unable to clear TCPC_ALERT_EXTENDED ret:%d\n", ret);
 112                return;
 113        }
 114
 115        /* Enable VSAFE0V detection */
 116        ret = max_tcpci_write8(chip, TCPC_EXTENDED_STATUS_MASK, TCPC_EXTENDED_STATUS_VSAFE0V);
 117        if (ret < 0) {
 118                dev_err(chip->dev, "Unable to unmask TCPC_EXTENDED_STATUS_VSAFE0V ret:%d\n", ret);
 119                return;
 120        }
 121
 122        alert_mask = TCPC_ALERT_TX_SUCCESS | TCPC_ALERT_TX_DISCARDED | TCPC_ALERT_TX_FAILED |
 123                TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_RX_STATUS | TCPC_ALERT_CC_STATUS |
 124                TCPC_ALERT_VBUS_DISCNCT | TCPC_ALERT_RX_BUF_OVF | TCPC_ALERT_POWER_STATUS |
 125                /* Enable Extended alert for detecting Fast Role Swap Signal */
 126                TCPC_ALERT_EXTND | TCPC_ALERT_EXTENDED_STATUS;
 127
 128        ret = max_tcpci_write16(chip, TCPC_ALERT_MASK, alert_mask);
 129        if (ret < 0) {
 130                dev_err(chip->dev,
 131                        "Error enabling TCPC_ALERT: TCPC_ALERT_MASK write failed ret:%d\n", ret);
 132                return;
 133        }
 134
 135        /* Enable vbus voltage monitoring and voltage alerts */
 136        ret = max_tcpci_write8(chip, TCPC_POWER_CTRL, 0);
 137        if (ret < 0) {
 138                dev_err(chip->dev, "Error writing to TCPC_POWER_CTRL ret:%d\n", ret);
 139                return;
 140        }
 141
 142        ret = max_tcpci_write8(chip, TCPC_ALERT_EXTENDED_MASK, TCPC_SINK_FAST_ROLE_SWAP);
 143        if (ret < 0)
 144                return;
 145}
 146
 147static void process_rx(struct max_tcpci_chip *chip, u16 status)
 148{
 149        struct pd_message msg;
 150        u8 count, frame_type, rx_buf[TCPC_RECEIVE_BUFFER_LEN];
 151        int ret, payload_index;
 152        u8 *rx_buf_ptr;
 153
 154        /*
 155         * READABLE_BYTE_COUNT: Indicates the number of bytes in the RX_BUF_BYTE_x registers
 156         * plus one (for the RX_BUF_FRAME_TYPE) Table 4-36.
 157         * Read the count and frame type.
 158         */
 159        ret = regmap_raw_read(chip->data.regmap, TCPC_RX_BYTE_CNT, rx_buf, 2);
 160        if (ret < 0) {
 161                dev_err(chip->dev, "TCPC_RX_BYTE_CNT read failed ret:%d\n", ret);
 162                return;
 163        }
 164
 165        count = rx_buf[TCPC_RECEIVE_BUFFER_COUNT_OFFSET];
 166        frame_type = rx_buf[TCPC_RECEIVE_BUFFER_FRAME_TYPE_OFFSET];
 167
 168        if (count == 0 || frame_type != TCPC_RX_BUF_FRAME_TYPE_SOP) {
 169                max_tcpci_write16(chip, TCPC_ALERT, TCPC_ALERT_RX_STATUS);
 170                dev_err(chip->dev, "%s\n", count ==  0 ? "error: count is 0" :
 171                        "error frame_type is not SOP");
 172                return;
 173        }
 174
 175        if (count > sizeof(struct pd_message) || count + 1 > TCPC_RECEIVE_BUFFER_LEN) {
 176                dev_err(chip->dev, "Invalid TCPC_RX_BYTE_CNT %d\n", count);
 177                return;
 178        }
 179
 180        /*
 181         * Read count + 1 as RX_BUF_BYTE_x is hidden and can only be read through
 182         * TCPC_RX_BYTE_CNT
 183         */
 184        count += 1;
 185        ret = regmap_raw_read(chip->data.regmap, TCPC_RX_BYTE_CNT, rx_buf, count);
 186        if (ret < 0) {
 187                dev_err(chip->dev, "Error: TCPC_RX_BYTE_CNT read failed: %d\n", ret);
 188                return;
 189        }
 190
 191        rx_buf_ptr = rx_buf + TCPC_RECEIVE_BUFFER_RX_BYTE_BUF_OFFSET;
 192        msg.header = cpu_to_le16(*(u16 *)rx_buf_ptr);
 193        rx_buf_ptr = rx_buf_ptr + sizeof(msg.header);
 194        for (payload_index = 0; payload_index < pd_header_cnt_le(msg.header); payload_index++,
 195             rx_buf_ptr += sizeof(msg.payload[0]))
 196                msg.payload[payload_index] = cpu_to_le32(*(u32 *)rx_buf_ptr);
 197
 198        /*
 199         * Read complete, clear RX status alert bit.
 200         * Clear overflow as well if set.
 201         */
 202        ret = max_tcpci_write16(chip, TCPC_ALERT, status & TCPC_ALERT_RX_BUF_OVF ?
 203                                TCPC_ALERT_RX_STATUS | TCPC_ALERT_RX_BUF_OVF :
 204                                TCPC_ALERT_RX_STATUS);
 205        if (ret < 0)
 206                return;
 207
 208        tcpm_pd_receive(chip->port, &msg);
 209}
 210
 211static int max_tcpci_set_vbus(struct tcpci *tcpci, struct tcpci_data *tdata, bool source, bool sink)
 212{
 213        struct max_tcpci_chip *chip = tdata_to_max_tcpci(tdata);
 214        u8 buffer_source[2] = {MAX_BUCK_BOOST_OP, MAX_BUCK_BOOST_SOURCE};
 215        u8 buffer_sink[2] = {MAX_BUCK_BOOST_OP, MAX_BUCK_BOOST_SINK};
 216        u8 buffer_none[2] = {MAX_BUCK_BOOST_OP, MAX_BUCK_BOOST_OFF};
 217        struct i2c_client *i2c = chip->client;
 218        int ret;
 219
 220        struct i2c_msg msgs[] = {
 221                {
 222                        .addr = MAX_BUCK_BOOST_SID,
 223                        .flags = i2c->flags & I2C_M_TEN,
 224                        .len = 2,
 225                        .buf = source ? buffer_source : sink ? buffer_sink : buffer_none,
 226                },
 227        };
 228
 229        if (source && sink) {
 230                dev_err(chip->dev, "Both source and sink set\n");
 231                return -EINVAL;
 232        }
 233
 234        ret = i2c_transfer(i2c->adapter, msgs, 1);
 235
 236        return  ret < 0 ? ret : 1;
 237}
 238
 239static void process_power_status(struct max_tcpci_chip *chip)
 240{
 241        u8 pwr_status;
 242        int ret;
 243
 244        ret = max_tcpci_read8(chip, TCPC_POWER_STATUS, &pwr_status);
 245        if (ret < 0)
 246                return;
 247
 248        if (pwr_status == 0xff)
 249                max_tcpci_init_regs(chip);
 250        else if (pwr_status & TCPC_POWER_STATUS_SOURCING_VBUS)
 251                tcpm_sourcing_vbus(chip->port);
 252        else
 253                tcpm_vbus_change(chip->port);
 254}
 255
 256static void max_tcpci_frs_sourcing_vbus(struct tcpci *tcpci, struct tcpci_data *tdata)
 257{
 258        /*
 259         * For Fast Role Swap case, Boost turns on autonomously without
 260         * AP intervention, but, needs AP to enable source mode explicitly
 261         * for AP to regain control.
 262         */
 263        max_tcpci_set_vbus(tcpci, tdata, true, false);
 264}
 265
 266static void process_tx(struct max_tcpci_chip *chip, u16 status)
 267{
 268        if (status & TCPC_ALERT_TX_SUCCESS)
 269                tcpm_pd_transmit_complete(chip->port, TCPC_TX_SUCCESS);
 270        else if (status & TCPC_ALERT_TX_DISCARDED)
 271                tcpm_pd_transmit_complete(chip->port, TCPC_TX_DISCARDED);
 272        else if (status & TCPC_ALERT_TX_FAILED)
 273                tcpm_pd_transmit_complete(chip->port, TCPC_TX_FAILED);
 274
 275        /* Reinit regs as Hard reset sets them to default value */
 276        if ((status & TCPC_ALERT_TX_SUCCESS) && (status & TCPC_ALERT_TX_FAILED))
 277                max_tcpci_init_regs(chip);
 278}
 279
 280/* Enable USB switches when partner is USB communications capable */
 281static void max_tcpci_set_partner_usb_comm_capable(struct tcpci *tcpci, struct tcpci_data *data,
 282                                                   bool capable)
 283{
 284        struct max_tcpci_chip *chip = tdata_to_max_tcpci(data);
 285        int ret;
 286
 287        ret = max_tcpci_write8(chip, TCPC_VENDOR_USBSW_CTRL, capable ?
 288                               TCPC_VENDOR_USBSW_CTRL_ENABLE_USB_DATA :
 289                               TCPC_VENDOR_USBSW_CTRL_DISABLE_USB_DATA);
 290
 291        if (ret < 0)
 292                dev_err(chip->dev, "Failed to enable USB switches");
 293}
 294
 295static irqreturn_t _max_tcpci_irq(struct max_tcpci_chip *chip, u16 status)
 296{
 297        u16 mask;
 298        int ret;
 299        u8 reg_status;
 300
 301        /*
 302         * Clear alert status for everything except RX_STATUS, which shouldn't
 303         * be cleared until we have successfully retrieved message.
 304         */
 305        if (status & ~TCPC_ALERT_RX_STATUS) {
 306                mask = status & TCPC_ALERT_RX_BUF_OVF ?
 307                        status & ~(TCPC_ALERT_RX_STATUS | TCPC_ALERT_RX_BUF_OVF) :
 308                        status & ~TCPC_ALERT_RX_STATUS;
 309                ret = max_tcpci_write16(chip, TCPC_ALERT, mask);
 310                if (ret < 0) {
 311                        dev_err(chip->dev, "ALERT clear failed\n");
 312                        return ret;
 313                }
 314        }
 315
 316        if (status & TCPC_ALERT_RX_BUF_OVF && !(status & TCPC_ALERT_RX_STATUS)) {
 317                ret = max_tcpci_write16(chip, TCPC_ALERT, (TCPC_ALERT_RX_STATUS |
 318                                                          TCPC_ALERT_RX_BUF_OVF));
 319                if (ret < 0) {
 320                        dev_err(chip->dev, "ALERT clear failed\n");
 321                        return ret;
 322                }
 323        }
 324
 325        if (status & TCPC_ALERT_EXTND) {
 326                ret = max_tcpci_read8(chip, TCPC_ALERT_EXTENDED, &reg_status);
 327                if (ret < 0)
 328                        return ret;
 329
 330                ret = max_tcpci_write8(chip, TCPC_ALERT_EXTENDED, reg_status);
 331                if (ret < 0)
 332                        return ret;
 333
 334                if (reg_status & TCPC_SINK_FAST_ROLE_SWAP) {
 335                        dev_info(chip->dev, "FRS Signal\n");
 336                        tcpm_sink_frs(chip->port);
 337                }
 338        }
 339
 340        if (status & TCPC_ALERT_EXTENDED_STATUS) {
 341                ret = max_tcpci_read8(chip, TCPC_EXTENDED_STATUS, (u8 *)&reg_status);
 342                if (ret >= 0 && (reg_status & TCPC_EXTENDED_STATUS_VSAFE0V))
 343                        tcpm_vbus_change(chip->port);
 344        }
 345
 346        if (status & TCPC_ALERT_RX_STATUS)
 347                process_rx(chip, status);
 348
 349        if (status & TCPC_ALERT_VBUS_DISCNCT)
 350                tcpm_vbus_change(chip->port);
 351
 352        if (status & TCPC_ALERT_CC_STATUS)
 353                tcpm_cc_change(chip->port);
 354
 355        if (status & TCPC_ALERT_POWER_STATUS)
 356                process_power_status(chip);
 357
 358        if (status & TCPC_ALERT_RX_HARD_RST) {
 359                tcpm_pd_hard_reset(chip->port);
 360                max_tcpci_init_regs(chip);
 361        }
 362
 363        if (status & TCPC_ALERT_TX_SUCCESS || status & TCPC_ALERT_TX_DISCARDED || status &
 364            TCPC_ALERT_TX_FAILED)
 365                process_tx(chip, status);
 366
 367        return IRQ_HANDLED;
 368}
 369
 370static irqreturn_t max_tcpci_irq(int irq, void *dev_id)
 371{
 372        struct max_tcpci_chip *chip = dev_id;
 373        u16 status;
 374        irqreturn_t irq_return = IRQ_HANDLED;
 375        int ret;
 376
 377        if (!chip->port)
 378                return IRQ_HANDLED;
 379
 380        ret = max_tcpci_read16(chip, TCPC_ALERT, &status);
 381        if (ret < 0) {
 382                dev_err(chip->dev, "ALERT read failed\n");
 383                return ret;
 384        }
 385        while (status) {
 386                irq_return = _max_tcpci_irq(chip, status);
 387                /* Do not return if the ALERT is already set. */
 388                ret = max_tcpci_read16(chip, TCPC_ALERT, &status);
 389                if (ret < 0)
 390                        break;
 391        }
 392
 393        return irq_return;
 394}
 395
 396static irqreturn_t max_tcpci_isr(int irq, void *dev_id)
 397{
 398        struct max_tcpci_chip *chip = dev_id;
 399
 400        pm_wakeup_event(chip->dev, PD_ACTIVITY_TIMEOUT_MS);
 401
 402        if (!chip->port)
 403                return IRQ_HANDLED;
 404
 405        return IRQ_WAKE_THREAD;
 406}
 407
 408static int max_tcpci_init_alert(struct max_tcpci_chip *chip, struct i2c_client *client)
 409{
 410        int ret;
 411
 412        ret = devm_request_threaded_irq(chip->dev, client->irq, max_tcpci_isr, max_tcpci_irq,
 413                                        (IRQF_TRIGGER_LOW | IRQF_ONESHOT), dev_name(chip->dev),
 414                                        chip);
 415
 416        if (ret < 0)
 417                return ret;
 418
 419        enable_irq_wake(client->irq);
 420        return 0;
 421}
 422
 423static int max_tcpci_start_toggling(struct tcpci *tcpci, struct tcpci_data *tdata,
 424                                    enum typec_cc_status cc)
 425{
 426        struct max_tcpci_chip *chip = tdata_to_max_tcpci(tdata);
 427
 428        max_tcpci_init_regs(chip);
 429
 430        return 0;
 431}
 432
 433static int tcpci_init(struct tcpci *tcpci, struct tcpci_data *data)
 434{
 435        /*
 436         * Generic TCPCI overwrites the regs once this driver initializes
 437         * them. Prevent this by returning -1.
 438         */
 439        return -1;
 440}
 441
 442static int max_tcpci_probe(struct i2c_client *client, const struct i2c_device_id *i2c_id)
 443{
 444        int ret;
 445        struct max_tcpci_chip *chip;
 446        u8 power_status;
 447
 448        chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 449        if (!chip)
 450                return -ENOMEM;
 451
 452        chip->client = client;
 453        chip->data.regmap = devm_regmap_init_i2c(client, &max_tcpci_regmap_config);
 454        if (IS_ERR(chip->data.regmap)) {
 455                dev_err(&client->dev, "Regmap init failed\n");
 456                return PTR_ERR(chip->data.regmap);
 457        }
 458
 459        chip->dev = &client->dev;
 460        i2c_set_clientdata(client, chip);
 461
 462        ret = max_tcpci_read8(chip, TCPC_POWER_STATUS, &power_status);
 463        if (ret < 0)
 464                return ret;
 465
 466        /* Chip level tcpci callbacks */
 467        chip->data.set_vbus = max_tcpci_set_vbus;
 468        chip->data.start_drp_toggling = max_tcpci_start_toggling;
 469        chip->data.TX_BUF_BYTE_x_hidden = true;
 470        chip->data.init = tcpci_init;
 471        chip->data.frs_sourcing_vbus = max_tcpci_frs_sourcing_vbus;
 472        chip->data.auto_discharge_disconnect = true;
 473        chip->data.vbus_vsafe0v = true;
 474        chip->data.set_partner_usb_comm_capable = max_tcpci_set_partner_usb_comm_capable;
 475
 476        max_tcpci_init_regs(chip);
 477        chip->tcpci = tcpci_register_port(chip->dev, &chip->data);
 478        if (IS_ERR(chip->tcpci)) {
 479                dev_err(&client->dev, "TCPCI port registration failed\n");
 480                return PTR_ERR(chip->tcpci);
 481        }
 482        chip->port = tcpci_get_tcpm_port(chip->tcpci);
 483        ret = max_tcpci_init_alert(chip, client);
 484        if (ret < 0)
 485                goto unreg_port;
 486
 487        device_init_wakeup(chip->dev, true);
 488        return 0;
 489
 490unreg_port:
 491        tcpci_unregister_port(chip->tcpci);
 492
 493        return ret;
 494}
 495
 496static int max_tcpci_remove(struct i2c_client *client)
 497{
 498        struct max_tcpci_chip *chip = i2c_get_clientdata(client);
 499
 500        if (!IS_ERR_OR_NULL(chip->tcpci))
 501                tcpci_unregister_port(chip->tcpci);
 502
 503        return 0;
 504}
 505
 506static const struct i2c_device_id max_tcpci_id[] = {
 507        { "maxtcpc", 0 },
 508        { }
 509};
 510MODULE_DEVICE_TABLE(i2c, max_tcpci_id);
 511
 512#ifdef CONFIG_OF
 513static const struct of_device_id max_tcpci_of_match[] = {
 514        { .compatible = "maxim,max33359", },
 515        {},
 516};
 517MODULE_DEVICE_TABLE(of, max_tcpci_of_match);
 518#endif
 519
 520static struct i2c_driver max_tcpci_i2c_driver = {
 521        .driver = {
 522                .name = "maxtcpc",
 523                .of_match_table = of_match_ptr(max_tcpci_of_match),
 524        },
 525        .probe = max_tcpci_probe,
 526        .remove = max_tcpci_remove,
 527        .id_table = max_tcpci_id,
 528};
 529module_i2c_driver(max_tcpci_i2c_driver);
 530
 531MODULE_AUTHOR("Badhri Jagan Sridharan <badhri@google.com>");
 532MODULE_DESCRIPTION("Maxim TCPCI based USB Type-C Port Controller Interface Driver");
 533MODULE_LICENSE("GPL v2");
 534