drivers/misc/mei/vsc-tp.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2023, Intel Corporation.
   4  * Intel Visual Sensing Controller Transport Layer Linux driver
   5  */
   6
   7 #include <linux/acpi.h>
   8 #include <linux/cleanup.h>
   9 #include <linux/crc32.h>
  10 #include <linux/delay.h>
  11 #include <linux/device.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/iopoll.h>
  14 #include <linux/irq.h>
  15 #include <linux/irqreturn.h>
  16 #include <linux/module.h>
  17 #include <linux/mutex.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/spi/spi.h>
  20 #include <linux/types.h>
  21
  22 #include "vsc-tp.h"
  23
  24 #define VSC_TP_RESET_PIN_TOGGLE_INTERVAL_MS     20
  25 #define VSC_TP_ROM_BOOTUP_DELAY_MS              10
  26 #define VSC_TP_ROM_XFER_POLL_TIMEOUT_US         (500 * USEC_PER_MSEC)
  27 #define VSC_TP_ROM_XFER_POLL_DELAY_US           (20 * USEC_PER_MSEC)
  28 #define VSC_TP_WAIT_FW_POLL_TIMEOUT             (2 * HZ)
  29 #define VSC_TP_WAIT_FW_POLL_DELAY_US            (20 * USEC_PER_MSEC)
  30 #define VSC_TP_MAX_XFER_COUNT                   5
  31
  32 #define VSC_TP_PACKET_SYNC                      0x31
  33 #define VSC_TP_CRC_SIZE                         sizeof(u32)
  34 #define VSC_TP_MAX_MSG_SIZE                     2048
  35 /* SPI xfer timeout size */
  36 #define VSC_TP_XFER_TIMEOUT_BYTES               700
  37 #define VSC_TP_PACKET_PADDING_SIZE              1
  38 #define VSC_TP_PACKET_SIZE(pkt) \
  39         (sizeof(struct vsc_tp_packet) + le16_to_cpu((pkt)->len) + VSC_TP_CRC_SIZE)
  40 #define VSC_TP_MAX_PACKET_SIZE \
  41         (sizeof(struct vsc_tp_packet) + VSC_TP_MAX_MSG_SIZE + VSC_TP_CRC_SIZE)
  42 #define VSC_TP_MAX_XFER_SIZE \
  43         (VSC_TP_MAX_PACKET_SIZE + VSC_TP_XFER_TIMEOUT_BYTES)
  44 #define VSC_TP_NEXT_XFER_LEN(len, offset) \
  45         (len + sizeof(struct vsc_tp_packet) + VSC_TP_CRC_SIZE - offset + VSC_TP_PACKET_PADDING_SIZE)
  46
  47 struct vsc_tp_packet {
  48         __u8 sync;
  49         __u8 cmd;
  50         __le16 len;
  51         __le32 seq;
  52         __u8 buf[] __counted_by(len);
  53 };
  54
  55 struct vsc_tp {
  56         /* do the actual data transfer */
  57         struct spi_device *spi;
  58
  59         /* bind with mei framework */
  60         struct platform_device *pdev;
  61
  62         struct gpio_desc *wakeuphost;
  63         struct gpio_desc *resetfw;
  64         struct gpio_desc *wakeupfw;
  65
  66         /* command sequence number */
  67         u32 seq;
  68
  69         /* command buffer */
  70         void *tx_buf;
  71         void *rx_buf;
  72
  73         atomic_t assert_cnt;
  74         wait_queue_head_t xfer_wait;
  75
  76         vsc_tp_event_cb_t event_notify;
  77         void *event_notify_context;
  78
  79         /* used to protect command download */
  80         struct mutex mutex;
  81 };
  82
  83 /* GPIO resources */
  84 static const struct acpi_gpio_params wakeuphost_gpio = { 0, 0, false };
  85 static const struct acpi_gpio_params wakeuphostint_gpio = { 1, 0, false };
  86 static const struct acpi_gpio_params resetfw_gpio = { 2, 0, false };
  87 static const struct acpi_gpio_params wakeupfw = { 3, 0, false };
  88
  89 static const struct acpi_gpio_mapping vsc_tp_acpi_gpios[] = {
  90         { "wakeuphost-gpios", &wakeuphost_gpio, 1 },
  91         { "wakeuphostint-gpios", &wakeuphostint_gpio, 1 },
  92         { "resetfw-gpios", &resetfw_gpio, 1 },
  93         { "wakeupfw-gpios", &wakeupfw, 1 },
  94         {}
  95 };
  96
  97 /* wakeup firmware and wait for response */
  98 static int vsc_tp_wakeup_request(struct vsc_tp *tp)
  99 {
 100         int ret;
 101
 102         gpiod_set_value_cansleep(tp->wakeupfw, 0);
 103
 104         ret = wait_event_timeout(tp->xfer_wait,
 105                                  atomic_read(&tp->assert_cnt),
 106                                  VSC_TP_WAIT_FW_POLL_TIMEOUT);
 107         if (!ret)
 108                 return -ETIMEDOUT;
 109
 110         return read_poll_timeout(gpiod_get_value_cansleep, ret, ret,
 111                                  VSC_TP_WAIT_FW_POLL_DELAY_US,
 112                                  VSC_TP_WAIT_FW_POLL_TIMEOUT, false,
 113                                  tp->wakeuphost);
 114 }
 115
 116 static void vsc_tp_wakeup_release(struct vsc_tp *tp)
 117 {
 118         atomic_dec_if_positive(&tp->assert_cnt);
 119
 120         gpiod_set_value_cansleep(tp->wakeupfw, 1);
 121 }
 122
 123 static int vsc_tp_dev_xfer(struct vsc_tp *tp, void *obuf, void *ibuf, size_t len)
 124 {
 125         struct spi_message msg = { 0 };
 126         struct spi_transfer xfer = {
 127                 .tx_buf = obuf,
 128                 .rx_buf = ibuf,
 129                 .len = len,
 130         };
 131
 132         spi_message_init_with_transfers(&msg, &xfer, 1);
 133
 134         return spi_sync_locked(tp->spi, &msg);
 135 }
 136
 137 static int vsc_tp_xfer_helper(struct vsc_tp *tp, struct vsc_tp_packet *pkt,
 138                               void *ibuf, u16 ilen)
 139 {
 140         int ret, offset = 0, cpy_len, src_len, dst_len = sizeof(struct vsc_tp_packet);
 141         int next_xfer_len = VSC_TP_PACKET_SIZE(pkt) + VSC_TP_XFER_TIMEOUT_BYTES;
 142         u8 *src, *crc_src, *rx_buf = tp->rx_buf;
 143         int count_down = VSC_TP_MAX_XFER_COUNT;
 144         u32 recv_crc = 0, crc = ~0;
 145         struct vsc_tp_packet ack;
 146         u8 *dst = (u8 *)&ack;
 147         bool synced = false;
 148
 149         do {
 150                 ret = vsc_tp_dev_xfer(tp, pkt, rx_buf, next_xfer_len);
 151                 if (ret)
 152                         return ret;
 153                 memset(pkt, 0, VSC_TP_MAX_XFER_SIZE);
 154
 155                 if (synced) {
 156                         src = rx_buf;
 157                         src_len = next_xfer_len;
 158                 } else {
 159                         src = memchr(rx_buf, VSC_TP_PACKET_SYNC, next_xfer_len);
 160                         if (!src)
 161                                 continue;
 162                         synced = true;
 163                         src_len = next_xfer_len - (src - rx_buf);
 164                 }
 165
 166                 /* traverse received data */
 167                 while (src_len > 0) {
 168                         cpy_len = min(src_len, dst_len);
 169                         memcpy(dst, src, cpy_len);
 170                         crc_src = src;
 171                         src += cpy_len;
 172                         src_len -= cpy_len;
 173                         dst += cpy_len;
 174                         dst_len -= cpy_len;
 175
 176                         if (offset < sizeof(ack)) {
 177                                 offset += cpy_len;
 178                                 crc = crc32(crc, crc_src, cpy_len);
 179
 180                                 if (!src_len)
 181                                         continue;
 182
 183                                 if (le16_to_cpu(ack.len)) {
 184                                         dst = ibuf;
 185                                         dst_len = min(ilen, le16_to_cpu(ack.len));
 186                                 } else {
 187                                         dst = (u8 *)&recv_crc;
 188                                         dst_len = sizeof(recv_crc);
 189                                 }
 190                         } else if (offset < sizeof(ack) + le16_to_cpu(ack.len)) {
 191                                 offset += cpy_len;
 192                                 crc = crc32(crc, crc_src, cpy_len);
 193
 194                                 if (src_len) {
 195                                         int remain = sizeof(ack) + le16_to_cpu(ack.len) - offset;
 196
 197                                         cpy_len = min(src_len, remain);
 198                                         offset += cpy_len;
 199                                         crc = crc32(crc, src, cpy_len);
 200                                         src += cpy_len;
 201                                         src_len -= cpy_len;
 202                                         if (src_len) {
 203                                                 dst = (u8 *)&recv_crc;
 204                                                 dst_len = sizeof(recv_crc);
 205                                                 continue;
 206                                         }
 207                                 }
 208                                 next_xfer_len = VSC_TP_NEXT_XFER_LEN(le16_to_cpu(ack.len), offset);
 209                         } else if (offset < sizeof(ack) + le16_to_cpu(ack.len) + VSC_TP_CRC_SIZE) {
 210                                 offset += cpy_len;
 211
 212                                 if (src_len) {
 213                                         /* terminate the traverse */
 214                                         next_xfer_len = 0;
 215                                         break;
 216                                 }
 217                                 next_xfer_len = VSC_TP_NEXT_XFER_LEN(le16_to_cpu(ack.len), offset);
 218                         }
 219                 }
 220         } while (next_xfer_len > 0 && --count_down);
 221
 222         if (next_xfer_len > 0)
 223                 return -EAGAIN;
 224
 225         if (~recv_crc != crc || le32_to_cpu(ack.seq) != tp->seq) {
 226                 dev_err(&tp->spi->dev, "recv crc or seq error\n");
 227                 return -EINVAL;
 228         }
 229
 230         if (ack.cmd == VSC_TP_CMD_ACK || ack.cmd == VSC_TP_CMD_NACK ||
 231             ack.cmd == VSC_TP_CMD_BUSY) {
 232                 dev_err(&tp->spi->dev, "recv cmd ack error\n");
 233                 return -EAGAIN;
 234         }
 235
 236         return min(le16_to_cpu(ack.len), ilen);
 237 }
 238
 239 /**
 240  * vsc_tp_xfer - transfer data to firmware
 241  * @tp: vsc_tp device handle
 242  * @cmd: the command to be sent to the device
 243  * @obuf: the tx buffer to be sent to the device
 244  * @olen: the length of tx buffer
 245  * @ibuf: the rx buffer to receive from the device
 246  * @ilen: the length of rx buffer
 247  * Return: the length of received data in case of success,
 248  *      otherwise negative value
 249  */
 250 int vsc_tp_xfer(struct vsc_tp *tp, u8 cmd, const void *obuf, size_t olen,
 251                 void *ibuf, size_t ilen)
 252 {
 253         struct vsc_tp_packet *pkt = tp->tx_buf;
 254         u32 crc;
 255         int ret;
 256
 257         if (!obuf || !ibuf || olen > VSC_TP_MAX_MSG_SIZE)
 258                 return -EINVAL;
 259
 260         guard(mutex)(&tp->mutex);
 261
 262         pkt->sync = VSC_TP_PACKET_SYNC;
 263         pkt->cmd = cmd;
 264         pkt->len = cpu_to_le16(olen);
 265         pkt->seq = cpu_to_le32(++tp->seq);
 266         memcpy(pkt->buf, obuf, olen);
 267
 268         crc = ~crc32(~0, (u8 *)pkt, sizeof(pkt) + olen);
 269         memcpy(pkt->buf + olen, &crc, sizeof(crc));
 270
 271         ret = vsc_tp_wakeup_request(tp);
 272         if (unlikely(ret))
 273                 dev_err(&tp->spi->dev, "wakeup firmware failed ret: %d\n", ret);
 274         else
 275                 ret = vsc_tp_xfer_helper(tp, pkt, ibuf, ilen);
 276
 277         vsc_tp_wakeup_release(tp);
 278
 279         return ret;
 280 }
 281 EXPORT_SYMBOL_NS_GPL(vsc_tp_xfer, VSC_TP);
 282
 283 /**
 284  * vsc_tp_rom_xfer - transfer data to rom code
 285  * @tp: vsc_tp device handle
 286  * @obuf: the data buffer to be sent to the device
 287  * @ibuf: the buffer to receive data from the device
 288  * @len: the length of tx buffer and rx buffer
 289  * Return: 0 in case of success, negative value in case of error
 290  */
 291 int vsc_tp_rom_xfer(struct vsc_tp *tp, const void *obuf, void *ibuf, size_t len)
 292 {
 293         size_t words = len / sizeof(__be32);
 294         int ret;
 295
 296         if (len % sizeof(__be32) || len > VSC_TP_MAX_MSG_SIZE)
 297                 return -EINVAL;
 298
 299         guard(mutex)(&tp->mutex);
 300
 301         /* rom xfer is big endian */
 302         cpu_to_be32_array(tp->tx_buf, obuf, words);
 303
 304         ret = read_poll_timeout(gpiod_get_value_cansleep, ret,
 305                                 !ret, VSC_TP_ROM_XFER_POLL_DELAY_US,
 306                                 VSC_TP_ROM_XFER_POLL_TIMEOUT_US, false,
 307                                 tp->wakeuphost);
 308         if (ret) {
 309                 dev_err(&tp->spi->dev, "wait rom failed ret: %d\n", ret);
 310                 return ret;
 311         }
 312
 313         ret = vsc_tp_dev_xfer(tp, tp->tx_buf, tp->rx_buf, len);
 314         if (ret)
 315                 return ret;
 316
 317         if (ibuf)
 318                 cpu_to_be32_array(ibuf, tp->rx_buf, words);
 319
 320         return ret;
 321 }
 322
 323 /**
 324  * vsc_tp_reset - reset vsc transport layer
 325  * @tp: vsc_tp device handle
 326  */
 327 void vsc_tp_reset(struct vsc_tp *tp)
 328 {
 329         disable_irq(tp->spi->irq);
 330
 331         /* toggle reset pin */
 332         gpiod_set_value_cansleep(tp->resetfw, 0);
 333         msleep(VSC_TP_RESET_PIN_TOGGLE_INTERVAL_MS);
 334         gpiod_set_value_cansleep(tp->resetfw, 1);
 335
 336         /* wait for ROM */
 337         msleep(VSC_TP_ROM_BOOTUP_DELAY_MS);
 338
 339         /*
 340          * Set default host wakeup pin to non-active
 341          * to avoid unexpected host irq interrupt.
 342          */
 343         gpiod_set_value_cansleep(tp->wakeupfw, 1);
 344
 345         atomic_set(&tp->assert_cnt, 0);
 346
 347         enable_irq(tp->spi->irq);
 348 }
 349 EXPORT_SYMBOL_NS_GPL(vsc_tp_reset, VSC_TP);
 350
 351 /**
 352  * vsc_tp_need_read - check if device has data to sent
 353  * @tp: vsc_tp device handle
 354  * Return: true if device has data to sent, otherwise false
 355  */
 356 bool vsc_tp_need_read(struct vsc_tp *tp)
 357 {
 358         if (!atomic_read(&tp->assert_cnt))
 359                 return false;
 360         if (!gpiod_get_value_cansleep(tp->wakeuphost))
 361                 return false;
 362         if (!gpiod_get_value_cansleep(tp->wakeupfw))
 363                 return false;
 364
 365         return true;
 366 }
 367 EXPORT_SYMBOL_NS_GPL(vsc_tp_need_read, VSC_TP);
 368
 369 /**
 370  * vsc_tp_register_event_cb - register a callback function to receive event
 371  * @tp: vsc_tp device handle
 372  * @event_cb: callback function
 373  * @context: execution context of event callback
 374  * Return: 0 in case of success, negative value in case of error
 375  */
 376 int vsc_tp_register_event_cb(struct vsc_tp *tp, vsc_tp_event_cb_t event_cb,
 377                             void *context)
 378 {
 379         tp->event_notify = event_cb;
 380         tp->event_notify_context = context;
 381
 382         return 0;
 383 }
 384 EXPORT_SYMBOL_NS_GPL(vsc_tp_register_event_cb, VSC_TP);
 385
 386 /**
 387  * vsc_tp_intr_synchronize - synchronize vsc_tp interrupt
 388  * @tp: vsc_tp device handle
 389  */
 390 void vsc_tp_intr_synchronize(struct vsc_tp *tp)
 391 {
 392         synchronize_irq(tp->spi->irq);
 393 }
 394 EXPORT_SYMBOL_NS_GPL(vsc_tp_intr_synchronize, VSC_TP);
 395
 396 /**
 397  * vsc_tp_intr_enable - enable vsc_tp interrupt
 398  * @tp: vsc_tp device handle
 399  */
 400 void vsc_tp_intr_enable(struct vsc_tp *tp)
 401 {
 402         enable_irq(tp->spi->irq);
 403 }
 404 EXPORT_SYMBOL_NS_GPL(vsc_tp_intr_enable, VSC_TP);
 405
 406 /**
 407  * vsc_tp_intr_disable - disable vsc_tp interrupt
 408  * @tp: vsc_tp device handle
 409  */
 410 void vsc_tp_intr_disable(struct vsc_tp *tp)
 411 {
 412         disable_irq(tp->spi->irq);
 413 }
 414 EXPORT_SYMBOL_NS_GPL(vsc_tp_intr_disable, VSC_TP);
 415
 416 static irqreturn_t vsc_tp_isr(int irq, void *data)
 417 {
 418         struct vsc_tp *tp = data;
 419
 420         atomic_inc(&tp->assert_cnt);
 421
 422         return IRQ_WAKE_THREAD;
 423 }
 424
 425 static irqreturn_t vsc_tp_thread_isr(int irq, void *data)
 426 {
 427         struct vsc_tp *tp = data;
 428
 429         wake_up(&tp->xfer_wait);
 430
 431         if (tp->event_notify)
 432                 tp->event_notify(tp->event_notify_context);
 433
 434         return IRQ_HANDLED;
 435 }
 436
 437 static int vsc_tp_match_any(struct acpi_device *adev, void *data)
 438 {
 439         struct acpi_device **__adev = data;
 440
 441         *__adev = adev;
 442
 443         return 1;
 444 }
 445
 446 static int vsc_tp_probe(struct spi_device *spi)
 447 {
 448         struct vsc_tp *tp;
 449         struct platform_device_info pinfo = {
 450                 .name = "intel_vsc",
 451                 .data = &tp,
 452                 .size_data = sizeof(tp),
 453                 .id = PLATFORM_DEVID_NONE,
 454         };
 455         struct device *dev = &spi->dev;
 456         struct platform_device *pdev;
 457         struct acpi_device *adev;
 458         int ret;
 459
 460         tp = devm_kzalloc(dev, sizeof(*tp), GFP_KERNEL);
 461         if (!tp)
 462                 return -ENOMEM;
 463
 464         tp->tx_buf = devm_kzalloc(dev, VSC_TP_MAX_XFER_SIZE, GFP_KERNEL);
 465         if (!tp->tx_buf)
 466                 return -ENOMEM;
 467
 468         tp->rx_buf = devm_kzalloc(dev, VSC_TP_MAX_XFER_SIZE, GFP_KERNEL);
 469         if (!tp->rx_buf)
 470                 return -ENOMEM;
 471
 472         ret = devm_acpi_dev_add_driver_gpios(dev, vsc_tp_acpi_gpios);
 473         if (ret)
 474                 return ret;
 475
 476         tp->wakeuphost = devm_gpiod_get(dev, "wakeuphost", GPIOD_IN);
 477         if (IS_ERR(tp->wakeuphost))
 478                 return PTR_ERR(tp->wakeuphost);
 479
 480         tp->resetfw = devm_gpiod_get(dev, "resetfw", GPIOD_OUT_HIGH);
 481         if (IS_ERR(tp->resetfw))
 482                 return PTR_ERR(tp->resetfw);
 483
 484         tp->wakeupfw = devm_gpiod_get(dev, "wakeupfw", GPIOD_OUT_HIGH);
 485         if (IS_ERR(tp->wakeupfw))
 486                 return PTR_ERR(tp->wakeupfw);
 487
 488         atomic_set(&tp->assert_cnt, 0);
 489         init_waitqueue_head(&tp->xfer_wait);
 490         tp->spi = spi;
 491
 492         irq_set_status_flags(spi->irq, IRQ_DISABLE_UNLAZY);
 493         ret = devm_request_threaded_irq(dev, spi->irq, vsc_tp_isr,
 494                                         vsc_tp_thread_isr,
 495                                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 496                                         dev_name(dev), tp);
 497         if (ret)
 498                 return ret;
 499
 500         mutex_init(&tp->mutex);
 501
 502         /* only one child acpi device */
 503         ret = acpi_dev_for_each_child(ACPI_COMPANION(dev),
 504                                       vsc_tp_match_any, &adev);
 505         if (!ret) {
 506                 ret = -ENODEV;
 507                 goto err_destroy_lock;
 508         }
 509
 510         pinfo.fwnode = acpi_fwnode_handle(adev);
 511         pdev = platform_device_register_full(&pinfo);
 512         if (IS_ERR(pdev)) {
 513                 ret = PTR_ERR(pdev);
 514                 goto err_destroy_lock;
 515         }
 516
 517         tp->pdev = pdev;
 518         spi_set_drvdata(spi, tp);
 519
 520         return 0;
 521
 522 err_destroy_lock:
 523         mutex_destroy(&tp->mutex);
 524
 525         return ret;
 526 }
 527
 528 static void vsc_tp_remove(struct spi_device *spi)
 529 {
 530         struct vsc_tp *tp = spi_get_drvdata(spi);
 531
 532         platform_device_unregister(tp->pdev);
 533
 534         mutex_destroy(&tp->mutex);
 535 }
 536
 537 static const struct acpi_device_id vsc_tp_acpi_ids[] = {
 538         { "INTC1009" }, /* Raptor Lake */
 539         { "INTC1058" }, /* Tiger Lake */
 540         { "INTC1094" }, /* Alder Lake */
 541         { "INTC10D0" }, /* Meteor Lake */
 542         {}
 543 };
 544 MODULE_DEVICE_TABLE(acpi, vsc_tp_acpi_ids);
 545
 546 static struct spi_driver vsc_tp_driver = {
 547         .probe = vsc_tp_probe,
 548         .remove = vsc_tp_remove,
 549         .driver = {
 550                 .name = "vsc-tp",
 551                 .acpi_match_table = vsc_tp_acpi_ids,
 552         },
 553 };
 554 module_spi_driver(vsc_tp_driver);
 555
 556 MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
 557 MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
 558 MODULE_DESCRIPTION("Intel Visual Sensing Controller Transport Layer");
 559 MODULE_LICENSE("GPL");