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1// SPDX-License-Identifier: GPL-2.02// SPI interface for ChromeOS Embedded Controller3//4// Copyright (C) 2012 Google, Inc5 6#include <linux/delay.h>7#include <linux/kernel.h>8#include <linux/module.h>9#include <linux/of.h>10#include <linux/platform_data/cros_ec_commands.h>11#include <linux/platform_data/cros_ec_proto.h>12#include <linux/platform_device.h>13#include <linux/slab.h>14#include <linux/spi/spi.h>15#include <uapi/linux/sched/types.h>16 17#include "cros_ec.h"18 19/* The header byte, which follows the preamble */20#define EC_MSG_HEADER 0xec21 22/*23 * Number of EC preamble bytes we read at a time. Since it takes24 * about 400-500us for the EC to respond there is not a lot of25 * point in tuning this. If the EC could respond faster then26 * we could increase this so that might expect the preamble and27 * message to occur in a single transaction. However, the maximum28 * SPI transfer size is 256 bytes, so at 5MHz we need a response29 * time of perhaps <320us (200 bytes / 1600 bits).30 */31#define EC_MSG_PREAMBLE_COUNT 3232 33/*34 * Allow for a long time for the EC to respond. We support i2c35 * tunneling and support fairly long messages for the tunnel (24936 * bytes long at the moment). If we're talking to a 100 kHz device37 * on the other end and need to transfer ~256 bytes, then we need:38 * 10 us/bit * ~10 bits/byte * ~256 bytes = ~25ms39 *40 * We'll wait 8 times that to handle clock stretching and other41 * paranoia. Note that some battery gas gauge ICs claim to have a42 * clock stretch of 144ms in rare situations. That's incentive for43 * not directly passing i2c through, but it's too late for that for44 * existing hardware.45 *46 * It's pretty unlikely that we'll really see a 249 byte tunnel in47 * anything other than testing. If this was more common we might48 * consider having slow commands like this require a GET_STATUS49 * wait loop. The 'flash write' command would be another candidate50 * for this, clocking in at 2-3ms.51 */52#define EC_MSG_DEADLINE_MS 20053 54/*55 * Time between raising the SPI chip select (for the end of a56 * transaction) and dropping it again (for the next transaction).57 * If we go too fast, the EC will miss the transaction. We know that we58 * need at least 70 us with the 16 MHz STM32 EC, so go with 200 us to be59 * safe.60 */61#define EC_SPI_RECOVERY_TIME_NS (200 * 1000)62 63/**64 * struct cros_ec_spi - information about a SPI-connected EC65 *66 * @spi: SPI device we are connected to67 * @last_transfer_ns: time that we last finished a transfer.68 * @start_of_msg_delay: used to set the delay_usecs on the spi_transfer that69 * is sent when we want to turn on CS at the start of a transaction.70 * @end_of_msg_delay: used to set the delay_usecs on the spi_transfer that71 * is sent when we want to turn off CS at the end of a transaction.72 * @high_pri_worker: Used to schedule high priority work.73 */74struct cros_ec_spi {75 struct spi_device *spi;76 s64 last_transfer_ns;77 unsigned int start_of_msg_delay;78 unsigned int end_of_msg_delay;79 struct kthread_worker *high_pri_worker;80};81 82typedef int (*cros_ec_xfer_fn_t) (struct cros_ec_device *ec_dev,83 struct cros_ec_command *ec_msg);84 85/**86 * struct cros_ec_xfer_work_params - params for our high priority workers87 *88 * @work: The work_struct needed to queue work89 * @fn: The function to use to transfer90 * @ec_dev: ChromeOS EC device91 * @ec_msg: Message to transfer92 * @ret: The return value of the function93 */94 95struct cros_ec_xfer_work_params {96 struct kthread_work work;97 cros_ec_xfer_fn_t fn;98 struct cros_ec_device *ec_dev;99 struct cros_ec_command *ec_msg;100 int ret;101};102 103static void debug_packet(struct device *dev, const char *name, u8 *ptr,104 int len)105{106#ifdef DEBUG107 dev_dbg(dev, "%s: %*ph\n", name, len, ptr);108#endif109}110 111static int terminate_request(struct cros_ec_device *ec_dev)112{113 struct cros_ec_spi *ec_spi = ec_dev->priv;114 struct spi_message msg;115 struct spi_transfer trans;116 int ret;117 118 /*119 * Turn off CS, possibly adding a delay to ensure the rising edge120 * doesn't come too soon after the end of the data.121 */122 spi_message_init(&msg);123 memset(&trans, 0, sizeof(trans));124 trans.delay.value = ec_spi->end_of_msg_delay;125 trans.delay.unit = SPI_DELAY_UNIT_USECS;126 spi_message_add_tail(&trans, &msg);127 128 ret = spi_sync_locked(ec_spi->spi, &msg);129 130 /* Reset end-of-response timer */131 ec_spi->last_transfer_ns = ktime_get_ns();132 if (ret < 0) {133 dev_err(ec_dev->dev,134 "cs-deassert spi transfer failed: %d\n",135 ret);136 }137 138 return ret;139}140 141/**142 * receive_n_bytes - receive n bytes from the EC.143 *144 * Assumes buf is a pointer into the ec_dev->din buffer145 *146 * @ec_dev: ChromeOS EC device.147 * @buf: Pointer to the buffer receiving the data.148 * @n: Number of bytes received.149 */150static int receive_n_bytes(struct cros_ec_device *ec_dev, u8 *buf, int n)151{152 struct cros_ec_spi *ec_spi = ec_dev->priv;153 struct spi_transfer trans;154 struct spi_message msg;155 int ret;156 157 if (buf - ec_dev->din + n > ec_dev->din_size)158 return -EINVAL;159 160 memset(&trans, 0, sizeof(trans));161 trans.cs_change = 1;162 trans.rx_buf = buf;163 trans.len = n;164 165 spi_message_init(&msg);166 spi_message_add_tail(&trans, &msg);167 ret = spi_sync_locked(ec_spi->spi, &msg);168 if (ret < 0)169 dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);170 171 return ret;172}173 174/**175 * cros_ec_spi_receive_packet - Receive a packet from the EC.176 *177 * This function has two phases: reading the preamble bytes (since if we read178 * data from the EC before it is ready to send, we just get preamble) and179 * reading the actual message.180 *181 * The received data is placed into ec_dev->din.182 *183 * @ec_dev: ChromeOS EC device184 * @need_len: Number of message bytes we need to read185 */186static int cros_ec_spi_receive_packet(struct cros_ec_device *ec_dev,187 int need_len)188{189 struct ec_host_response *response;190 u8 *ptr, *end;191 int ret;192 unsigned long deadline;193 int todo;194 195 if (ec_dev->din_size < EC_MSG_PREAMBLE_COUNT)196 return -EINVAL;197 198 /* Receive data until we see the header byte */199 deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);200 while (true) {201 unsigned long start_jiffies = jiffies;202 203 ret = receive_n_bytes(ec_dev,204 ec_dev->din,205 EC_MSG_PREAMBLE_COUNT);206 if (ret < 0)207 return ret;208 209 ptr = ec_dev->din;210 for (end = ptr + EC_MSG_PREAMBLE_COUNT; ptr != end; ptr++) {211 if (*ptr == EC_SPI_FRAME_START) {212 dev_dbg(ec_dev->dev, "msg found at %zd\n",213 ptr - ec_dev->din);214 break;215 }216 }217 if (ptr != end)218 break;219 220 /*221 * Use the time at the start of the loop as a timeout. This222 * gives us one last shot at getting the transfer and is useful223 * in case we got context switched out for a while.224 */225 if (time_after(start_jiffies, deadline)) {226 dev_warn(ec_dev->dev, "EC failed to respond in time\n");227 return -ETIMEDOUT;228 }229 }230 231 /*232 * ptr now points to the header byte. Copy any valid data to the233 * start of our buffer234 */235 todo = end - ++ptr;236 todo = min(todo, need_len);237 memmove(ec_dev->din, ptr, todo);238 ptr = ec_dev->din + todo;239 dev_dbg(ec_dev->dev, "need %d, got %d bytes from preamble\n",240 need_len, todo);241 need_len -= todo;242 243 /* If the entire response struct wasn't read, get the rest of it. */244 if (todo < sizeof(*response)) {245 ret = receive_n_bytes(ec_dev, ptr, sizeof(*response) - todo);246 if (ret < 0)247 return -EBADMSG;248 ptr += (sizeof(*response) - todo);249 todo = sizeof(*response);250 }251 252 response = (struct ec_host_response *)ec_dev->din;253 254 /* Abort if data_len is too large. */255 if (response->data_len > ec_dev->din_size)256 return -EMSGSIZE;257 258 /* Receive data until we have it all */259 while (need_len > 0) {260 /*261 * We can't support transfers larger than the SPI FIFO size262 * unless we have DMA. We don't have DMA on the ISP SPI ports263 * for Exynos. We need a way of asking SPI driver for264 * maximum-supported transfer size.265 */266 todo = min(need_len, 256);267 dev_dbg(ec_dev->dev, "loop, todo=%d, need_len=%d, ptr=%zd\n",268 todo, need_len, ptr - ec_dev->din);269 270 ret = receive_n_bytes(ec_dev, ptr, todo);271 if (ret < 0)272 return ret;273 274 ptr += todo;275 need_len -= todo;276 }277 278 dev_dbg(ec_dev->dev, "loop done, ptr=%zd\n", ptr - ec_dev->din);279 280 return 0;281}282 283/**284 * cros_ec_spi_receive_response - Receive a response from the EC.285 *286 * This function has two phases: reading the preamble bytes (since if we read287 * data from the EC before it is ready to send, we just get preamble) and288 * reading the actual message.289 *290 * The received data is placed into ec_dev->din.291 *292 * @ec_dev: ChromeOS EC device293 * @need_len: Number of message bytes we need to read294 */295static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,296 int need_len)297{298 u8 *ptr, *end;299 int ret;300 unsigned long deadline;301 int todo;302 303 if (ec_dev->din_size < EC_MSG_PREAMBLE_COUNT)304 return -EINVAL;305 306 /* Receive data until we see the header byte */307 deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);308 while (true) {309 unsigned long start_jiffies = jiffies;310 311 ret = receive_n_bytes(ec_dev,312 ec_dev->din,313 EC_MSG_PREAMBLE_COUNT);314 if (ret < 0)315 return ret;316 317 ptr = ec_dev->din;318 for (end = ptr + EC_MSG_PREAMBLE_COUNT; ptr != end; ptr++) {319 if (*ptr == EC_SPI_FRAME_START) {320 dev_dbg(ec_dev->dev, "msg found at %zd\n",321 ptr - ec_dev->din);322 break;323 }324 }325 if (ptr != end)326 break;327 328 /*329 * Use the time at the start of the loop as a timeout. This330 * gives us one last shot at getting the transfer and is useful331 * in case we got context switched out for a while.332 */333 if (time_after(start_jiffies, deadline)) {334 dev_warn(ec_dev->dev, "EC failed to respond in time\n");335 return -ETIMEDOUT;336 }337 }338 339 /*340 * ptr now points to the header byte. Copy any valid data to the341 * start of our buffer342 */343 todo = end - ++ptr;344 todo = min(todo, need_len);345 memmove(ec_dev->din, ptr, todo);346 ptr = ec_dev->din + todo;347 dev_dbg(ec_dev->dev, "need %d, got %d bytes from preamble\n",348 need_len, todo);349 need_len -= todo;350 351 /* Receive data until we have it all */352 while (need_len > 0) {353 /*354 * We can't support transfers larger than the SPI FIFO size355 * unless we have DMA. We don't have DMA on the ISP SPI ports356 * for Exynos. We need a way of asking SPI driver for357 * maximum-supported transfer size.358 */359 todo = min(need_len, 256);360 dev_dbg(ec_dev->dev, "loop, todo=%d, need_len=%d, ptr=%zd\n",361 todo, need_len, ptr - ec_dev->din);362 363 ret = receive_n_bytes(ec_dev, ptr, todo);364 if (ret < 0)365 return ret;366 367 debug_packet(ec_dev->dev, "interim", ptr, todo);368 ptr += todo;369 need_len -= todo;370 }371 372 dev_dbg(ec_dev->dev, "loop done, ptr=%zd\n", ptr - ec_dev->din);373 374 return 0;375}376 377/**378 * do_cros_ec_pkt_xfer_spi - Transfer a packet over SPI and receive the reply379 *380 * @ec_dev: ChromeOS EC device381 * @ec_msg: Message to transfer382 */383static int do_cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev,384 struct cros_ec_command *ec_msg)385{386 struct ec_host_response *response;387 struct cros_ec_spi *ec_spi = ec_dev->priv;388 struct spi_transfer trans, trans_delay;389 struct spi_message msg;390 int i, len;391 u8 *ptr;392 u8 *rx_buf;393 u8 sum;394 u8 rx_byte;395 int ret = 0, final_ret;396 unsigned long delay;397 398 len = cros_ec_prepare_tx(ec_dev, ec_msg);399 if (len < 0)400 return len;401 dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);402 403 /* If it's too soon to do another transaction, wait */404 delay = ktime_get_ns() - ec_spi->last_transfer_ns;405 if (delay < EC_SPI_RECOVERY_TIME_NS)406 ndelay(EC_SPI_RECOVERY_TIME_NS - delay);407 408 rx_buf = kzalloc(len, GFP_KERNEL);409 if (!rx_buf)410 return -ENOMEM;411 412 spi_bus_lock(ec_spi->spi->controller);413 414 /*415 * Leave a gap between CS assertion and clocking of data to allow the416 * EC time to wakeup.417 */418 spi_message_init(&msg);419 if (ec_spi->start_of_msg_delay) {420 memset(&trans_delay, 0, sizeof(trans_delay));421 trans_delay.delay.value = ec_spi->start_of_msg_delay;422 trans_delay.delay.unit = SPI_DELAY_UNIT_USECS;423 spi_message_add_tail(&trans_delay, &msg);424 }425 426 /* Transmit phase - send our message */427 memset(&trans, 0, sizeof(trans));428 trans.tx_buf = ec_dev->dout;429 trans.rx_buf = rx_buf;430 trans.len = len;431 trans.cs_change = 1;432 spi_message_add_tail(&trans, &msg);433 ret = spi_sync_locked(ec_spi->spi, &msg);434 435 /* Get the response */436 if (!ret) {437 /* Verify that EC can process command */438 for (i = 0; i < len; i++) {439 rx_byte = rx_buf[i];440 /*441 * Seeing the PAST_END, RX_BAD_DATA, or NOT_READY442 * markers are all signs that the EC didn't fully443 * receive our command. e.g., if the EC is flashing444 * itself, it can't respond to any commands and instead445 * clocks out EC_SPI_PAST_END from its SPI hardware446 * buffer. Similar occurrences can happen if the AP is447 * too slow to clock out data after asserting CS -- the448 * EC will abort and fill its buffer with449 * EC_SPI_RX_BAD_DATA.450 *451 * In all cases, these errors should be safe to retry.452 * Report -EAGAIN and let the caller decide what to do453 * about that.454 */455 if (rx_byte == EC_SPI_PAST_END ||456 rx_byte == EC_SPI_RX_BAD_DATA ||457 rx_byte == EC_SPI_NOT_READY) {458 ret = -EAGAIN;459 break;460 }461 }462 }463 464 if (!ret)465 ret = cros_ec_spi_receive_packet(ec_dev,466 ec_msg->insize + sizeof(*response));467 else if (ret != -EAGAIN)468 dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);469 470 final_ret = terminate_request(ec_dev);471 472 spi_bus_unlock(ec_spi->spi->controller);473 474 if (!ret)475 ret = final_ret;476 if (ret < 0)477 goto exit;478 479 ptr = ec_dev->din;480 481 /* check response error code */482 response = (struct ec_host_response *)ptr;483 ec_msg->result = response->result;484 485 ret = cros_ec_check_result(ec_dev, ec_msg);486 if (ret)487 goto exit;488 489 len = response->data_len;490 sum = 0;491 if (len > ec_msg->insize) {492 dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",493 len, ec_msg->insize);494 ret = -EMSGSIZE;495 goto exit;496 }497 498 for (i = 0; i < sizeof(*response); i++)499 sum += ptr[i];500 501 /* copy response packet payload and compute checksum */502 memcpy(ec_msg->data, ptr + sizeof(*response), len);503 for (i = 0; i < len; i++)504 sum += ec_msg->data[i];505 506 if (sum) {507 dev_err(ec_dev->dev,508 "bad packet checksum, calculated %x\n",509 sum);510 ret = -EBADMSG;511 goto exit;512 }513 514 ret = len;515exit:516 kfree(rx_buf);517 if (ec_msg->command == EC_CMD_REBOOT_EC)518 msleep(EC_REBOOT_DELAY_MS);519 520 return ret;521}522 523/**524 * do_cros_ec_cmd_xfer_spi - Transfer a message over SPI and receive the reply525 *526 * @ec_dev: ChromeOS EC device527 * @ec_msg: Message to transfer528 */529static int do_cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,530 struct cros_ec_command *ec_msg)531{532 struct cros_ec_spi *ec_spi = ec_dev->priv;533 struct spi_transfer trans;534 struct spi_message msg;535 int i, len;536 u8 *ptr;537 u8 *rx_buf;538 u8 rx_byte;539 int sum;540 int ret = 0, final_ret;541 unsigned long delay;542 543 len = cros_ec_prepare_tx(ec_dev, ec_msg);544 if (len < 0)545 return len;546 dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);547 548 /* If it's too soon to do another transaction, wait */549 delay = ktime_get_ns() - ec_spi->last_transfer_ns;550 if (delay < EC_SPI_RECOVERY_TIME_NS)551 ndelay(EC_SPI_RECOVERY_TIME_NS - delay);552 553 rx_buf = kzalloc(len, GFP_KERNEL);554 if (!rx_buf)555 return -ENOMEM;556 557 spi_bus_lock(ec_spi->spi->controller);558 559 /* Transmit phase - send our message */560 debug_packet(ec_dev->dev, "out", ec_dev->dout, len);561 memset(&trans, 0, sizeof(trans));562 trans.tx_buf = ec_dev->dout;563 trans.rx_buf = rx_buf;564 trans.len = len;565 trans.cs_change = 1;566 spi_message_init(&msg);567 spi_message_add_tail(&trans, &msg);568 ret = spi_sync_locked(ec_spi->spi, &msg);569 570 /* Get the response */571 if (!ret) {572 /* Verify that EC can process command */573 for (i = 0; i < len; i++) {574 rx_byte = rx_buf[i];575 /* See comments in cros_ec_pkt_xfer_spi() */576 if (rx_byte == EC_SPI_PAST_END ||577 rx_byte == EC_SPI_RX_BAD_DATA ||578 rx_byte == EC_SPI_NOT_READY) {579 ret = -EAGAIN;580 break;581 }582 }583 }584 585 if (!ret)586 ret = cros_ec_spi_receive_response(ec_dev,587 ec_msg->insize + EC_MSG_TX_PROTO_BYTES);588 else if (ret != -EAGAIN)589 dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);590 591 final_ret = terminate_request(ec_dev);592 593 spi_bus_unlock(ec_spi->spi->controller);594 595 if (!ret)596 ret = final_ret;597 if (ret < 0)598 goto exit;599 600 ptr = ec_dev->din;601 602 /* check response error code */603 ec_msg->result = ptr[0];604 ret = cros_ec_check_result(ec_dev, ec_msg);605 if (ret)606 goto exit;607 608 len = ptr[1];609 sum = ptr[0] + ptr[1];610 if (len > ec_msg->insize) {611 dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",612 len, ec_msg->insize);613 ret = -ENOSPC;614 goto exit;615 }616 617 /* copy response packet payload and compute checksum */618 for (i = 0; i < len; i++) {619 sum += ptr[i + 2];620 if (ec_msg->insize)621 ec_msg->data[i] = ptr[i + 2];622 }623 sum &= 0xff;624 625 debug_packet(ec_dev->dev, "in", ptr, len + 3);626 627 if (sum != ptr[len + 2]) {628 dev_err(ec_dev->dev,629 "bad packet checksum, expected %02x, got %02x\n",630 sum, ptr[len + 2]);631 ret = -EBADMSG;632 goto exit;633 }634 635 ret = len;636exit:637 kfree(rx_buf);638 if (ec_msg->command == EC_CMD_REBOOT_EC)639 msleep(EC_REBOOT_DELAY_MS);640 641 return ret;642}643 644static void cros_ec_xfer_high_pri_work(struct kthread_work *work)645{646 struct cros_ec_xfer_work_params *params;647 648 params = container_of(work, struct cros_ec_xfer_work_params, work);649 params->ret = params->fn(params->ec_dev, params->ec_msg);650}651 652static int cros_ec_xfer_high_pri(struct cros_ec_device *ec_dev,653 struct cros_ec_command *ec_msg,654 cros_ec_xfer_fn_t fn)655{656 struct cros_ec_spi *ec_spi = ec_dev->priv;657 struct cros_ec_xfer_work_params params = {658 .work = KTHREAD_WORK_INIT(params.work,659 cros_ec_xfer_high_pri_work),660 .ec_dev = ec_dev,661 .ec_msg = ec_msg,662 .fn = fn,663 };664 665 /*666 * This looks a bit ridiculous. Why do the work on a667 * different thread if we're just going to block waiting for668 * the thread to finish? The key here is that the thread is669 * running at high priority but the calling context might not670 * be. We need to be at high priority to avoid getting671 * context switched out for too long and the EC giving up on672 * the transfer.673 */674 kthread_queue_work(ec_spi->high_pri_worker, ¶ms.work);675 kthread_flush_work(¶ms.work);676 677 return params.ret;678}679 680static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev,681 struct cros_ec_command *ec_msg)682{683 return cros_ec_xfer_high_pri(ec_dev, ec_msg, do_cros_ec_pkt_xfer_spi);684}685 686static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,687 struct cros_ec_command *ec_msg)688{689 return cros_ec_xfer_high_pri(ec_dev, ec_msg, do_cros_ec_cmd_xfer_spi);690}691 692static void cros_ec_spi_dt_probe(struct cros_ec_spi *ec_spi, struct device *dev)693{694 struct device_node *np = dev->of_node;695 u32 val;696 int ret;697 698 ret = of_property_read_u32(np, "google,cros-ec-spi-pre-delay", &val);699 if (!ret)700 ec_spi->start_of_msg_delay = val;701 702 ret = of_property_read_u32(np, "google,cros-ec-spi-msg-delay", &val);703 if (!ret)704 ec_spi->end_of_msg_delay = val;705}706 707static void cros_ec_spi_high_pri_release(void *worker)708{709 kthread_destroy_worker(worker);710}711 712static int cros_ec_spi_devm_high_pri_alloc(struct device *dev,713 struct cros_ec_spi *ec_spi)714{715 int err;716 717 ec_spi->high_pri_worker =718 kthread_create_worker(0, "cros_ec_spi_high_pri");719 720 if (IS_ERR(ec_spi->high_pri_worker)) {721 err = PTR_ERR(ec_spi->high_pri_worker);722 dev_err(dev, "Can't create cros_ec high pri worker: %d\n", err);723 return err;724 }725 726 err = devm_add_action_or_reset(dev, cros_ec_spi_high_pri_release,727 ec_spi->high_pri_worker);728 if (err)729 return err;730 731 sched_set_fifo(ec_spi->high_pri_worker->task);732 733 return 0;734}735 736static int cros_ec_spi_probe(struct spi_device *spi)737{738 struct device *dev = &spi->dev;739 struct cros_ec_device *ec_dev;740 struct cros_ec_spi *ec_spi;741 int err;742 743 spi->rt = true;744 err = spi_setup(spi);745 if (err < 0)746 return err;747 748 ec_spi = devm_kzalloc(dev, sizeof(*ec_spi), GFP_KERNEL);749 if (ec_spi == NULL)750 return -ENOMEM;751 ec_spi->spi = spi;752 ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);753 if (!ec_dev)754 return -ENOMEM;755 756 /* Check for any DT properties */757 cros_ec_spi_dt_probe(ec_spi, dev);758 759 spi_set_drvdata(spi, ec_dev);760 ec_dev->dev = dev;761 ec_dev->priv = ec_spi;762 ec_dev->irq = spi->irq;763 ec_dev->cmd_xfer = cros_ec_cmd_xfer_spi;764 ec_dev->pkt_xfer = cros_ec_pkt_xfer_spi;765 ec_dev->phys_name = dev_name(&ec_spi->spi->dev);766 ec_dev->din_size = EC_MSG_PREAMBLE_COUNT +767 sizeof(struct ec_host_response) +768 sizeof(struct ec_response_get_protocol_info);769 ec_dev->dout_size = sizeof(struct ec_host_request);770 771 ec_spi->last_transfer_ns = ktime_get_ns();772 773 err = cros_ec_spi_devm_high_pri_alloc(dev, ec_spi);774 if (err)775 return err;776 777 err = cros_ec_register(ec_dev);778 if (err) {779 dev_err(dev, "cannot register EC\n");780 return err;781 }782 783 device_init_wakeup(&spi->dev, true);784 785 return 0;786}787 788static void cros_ec_spi_remove(struct spi_device *spi)789{790 struct cros_ec_device *ec_dev = spi_get_drvdata(spi);791 792 cros_ec_unregister(ec_dev);793}794 795#ifdef CONFIG_PM_SLEEP796static int cros_ec_spi_suspend(struct device *dev)797{798 struct cros_ec_device *ec_dev = dev_get_drvdata(dev);799 800 return cros_ec_suspend(ec_dev);801}802 803static int cros_ec_spi_resume(struct device *dev)804{805 struct cros_ec_device *ec_dev = dev_get_drvdata(dev);806 807 return cros_ec_resume(ec_dev);808}809#endif810 811static SIMPLE_DEV_PM_OPS(cros_ec_spi_pm_ops, cros_ec_spi_suspend,812 cros_ec_spi_resume);813 814static const struct of_device_id cros_ec_spi_of_match[] = {815 { .compatible = "google,cros-ec-spi", },816 { /* sentinel */ },817};818MODULE_DEVICE_TABLE(of, cros_ec_spi_of_match);819 820static const struct spi_device_id cros_ec_spi_id[] = {821 { "cros-ec-spi", 0 },822 { }823};824MODULE_DEVICE_TABLE(spi, cros_ec_spi_id);825 826static struct spi_driver cros_ec_driver_spi = {827 .driver = {828 .name = "cros-ec-spi",829 .of_match_table = cros_ec_spi_of_match,830 .pm = &cros_ec_spi_pm_ops,831 .probe_type = PROBE_PREFER_ASYNCHRONOUS,832 },833 .probe = cros_ec_spi_probe,834 .remove = cros_ec_spi_remove,835 .id_table = cros_ec_spi_id,836};837 838module_spi_driver(cros_ec_driver_spi);839 840MODULE_LICENSE("GPL v2");841MODULE_DESCRIPTION("SPI interface for ChromeOS Embedded Controller");842