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1// SPDX-License-Identifier: GPL-2.02/*3 * Greybus SPI library4 *5 * Copyright 2014-2016 Google Inc.6 * Copyright 2014-2016 Linaro Ltd.7 */8 9#include <linux/bitops.h>10#include <linux/kernel.h>11#include <linux/module.h>12#include <linux/slab.h>13#include <linux/greybus.h>14#include <linux/spi/spi.h>15 16#include "spilib.h"17 18struct gb_spilib {19 struct gb_connection *connection;20 struct device *parent;21 struct spi_transfer *first_xfer;22 struct spi_transfer *last_xfer;23 struct spilib_ops *ops;24 u32 rx_xfer_offset;25 u32 tx_xfer_offset;26 u32 last_xfer_size;27 unsigned int op_timeout;28 u16 mode;29 u16 flags;30 u32 bits_per_word_mask;31 u8 num_chipselect;32 u32 min_speed_hz;33 u32 max_speed_hz;34};35 36#define GB_SPI_STATE_MSG_DONE ((void *)0)37#define GB_SPI_STATE_MSG_IDLE ((void *)1)38#define GB_SPI_STATE_MSG_RUNNING ((void *)2)39#define GB_SPI_STATE_OP_READY ((void *)3)40#define GB_SPI_STATE_OP_DONE ((void *)4)41#define GB_SPI_STATE_MSG_ERROR ((void *)-1)42 43#define XFER_TIMEOUT_TOLERANCE 20044 45static struct spi_controller *get_controller_from_spi(struct gb_spilib *spi)46{47 return gb_connection_get_data(spi->connection);48}49 50static int tx_header_fit_operation(u32 tx_size, u32 count, size_t data_max)51{52 size_t headers_size;53 54 data_max -= sizeof(struct gb_spi_transfer_request);55 headers_size = (count + 1) * sizeof(struct gb_spi_transfer);56 57 return tx_size + headers_size > data_max ? 0 : 1;58}59 60static size_t calc_rx_xfer_size(u32 rx_size, u32 *tx_xfer_size, u32 len,61 size_t data_max)62{63 size_t rx_xfer_size;64 65 data_max -= sizeof(struct gb_spi_transfer_response);66 67 if (rx_size + len > data_max)68 rx_xfer_size = data_max - rx_size;69 else70 rx_xfer_size = len;71 72 /* if this is a write_read, for symmetry read the same as write */73 if (*tx_xfer_size && rx_xfer_size > *tx_xfer_size)74 rx_xfer_size = *tx_xfer_size;75 if (*tx_xfer_size && rx_xfer_size < *tx_xfer_size)76 *tx_xfer_size = rx_xfer_size;77 78 return rx_xfer_size;79}80 81static size_t calc_tx_xfer_size(u32 tx_size, u32 count, size_t len,82 size_t data_max)83{84 size_t headers_size;85 86 data_max -= sizeof(struct gb_spi_transfer_request);87 headers_size = (count + 1) * sizeof(struct gb_spi_transfer);88 89 if (tx_size + headers_size + len > data_max)90 return data_max - (tx_size + sizeof(struct gb_spi_transfer));91 92 return len;93}94 95static void clean_xfer_state(struct gb_spilib *spi)96{97 spi->first_xfer = NULL;98 spi->last_xfer = NULL;99 spi->rx_xfer_offset = 0;100 spi->tx_xfer_offset = 0;101 spi->last_xfer_size = 0;102 spi->op_timeout = 0;103}104 105static bool is_last_xfer_done(struct gb_spilib *spi)106{107 struct spi_transfer *last_xfer = spi->last_xfer;108 109 if ((spi->tx_xfer_offset + spi->last_xfer_size == last_xfer->len) ||110 (spi->rx_xfer_offset + spi->last_xfer_size == last_xfer->len))111 return true;112 113 return false;114}115 116static int setup_next_xfer(struct gb_spilib *spi, struct spi_message *msg)117{118 struct spi_transfer *last_xfer = spi->last_xfer;119 120 if (msg->state != GB_SPI_STATE_OP_DONE)121 return 0;122 123 /*124 * if we transferred all content of the last transfer, reset values and125 * check if this was the last transfer in the message126 */127 if (is_last_xfer_done(spi)) {128 spi->tx_xfer_offset = 0;129 spi->rx_xfer_offset = 0;130 spi->op_timeout = 0;131 if (last_xfer == list_last_entry(&msg->transfers,132 struct spi_transfer,133 transfer_list))134 msg->state = GB_SPI_STATE_MSG_DONE;135 else136 spi->first_xfer = list_next_entry(last_xfer,137 transfer_list);138 return 0;139 }140 141 spi->first_xfer = last_xfer;142 if (last_xfer->tx_buf)143 spi->tx_xfer_offset += spi->last_xfer_size;144 145 if (last_xfer->rx_buf)146 spi->rx_xfer_offset += spi->last_xfer_size;147 148 return 0;149}150 151static struct spi_transfer *get_next_xfer(struct spi_transfer *xfer,152 struct spi_message *msg)153{154 if (xfer == list_last_entry(&msg->transfers, struct spi_transfer,155 transfer_list))156 return NULL;157 158 return list_next_entry(xfer, transfer_list);159}160 161/* Routines to transfer data */162static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,163 struct gb_connection *connection, struct spi_message *msg)164{165 struct gb_spi_transfer_request *request;166 struct spi_device *dev = msg->spi;167 struct spi_transfer *xfer;168 struct gb_spi_transfer *gb_xfer;169 struct gb_operation *operation;170 u32 tx_size = 0, rx_size = 0, count = 0, xfer_len = 0, request_size;171 u32 tx_xfer_size = 0, rx_xfer_size = 0, len;172 u32 total_len = 0;173 unsigned int xfer_timeout;174 size_t data_max;175 void *tx_data;176 177 data_max = gb_operation_get_payload_size_max(connection);178 xfer = spi->first_xfer;179 180 /* Find number of transfers queued and tx/rx length in the message */181 182 while (msg->state != GB_SPI_STATE_OP_READY) {183 msg->state = GB_SPI_STATE_MSG_RUNNING;184 spi->last_xfer = xfer;185 186 if (!xfer->tx_buf && !xfer->rx_buf) {187 dev_err(spi->parent,188 "bufferless transfer, length %u\n", xfer->len);189 msg->state = GB_SPI_STATE_MSG_ERROR;190 return NULL;191 }192 193 tx_xfer_size = 0;194 rx_xfer_size = 0;195 196 if (xfer->tx_buf) {197 len = xfer->len - spi->tx_xfer_offset;198 if (!tx_header_fit_operation(tx_size, count, data_max))199 break;200 tx_xfer_size = calc_tx_xfer_size(tx_size, count,201 len, data_max);202 spi->last_xfer_size = tx_xfer_size;203 }204 205 if (xfer->rx_buf) {206 len = xfer->len - spi->rx_xfer_offset;207 rx_xfer_size = calc_rx_xfer_size(rx_size, &tx_xfer_size,208 len, data_max);209 spi->last_xfer_size = rx_xfer_size;210 }211 212 tx_size += tx_xfer_size;213 rx_size += rx_xfer_size;214 215 total_len += spi->last_xfer_size;216 count++;217 218 xfer = get_next_xfer(xfer, msg);219 if (!xfer || total_len >= data_max)220 msg->state = GB_SPI_STATE_OP_READY;221 }222 223 /*224 * In addition to space for all message descriptors we need225 * to have enough to hold all tx data.226 */227 request_size = sizeof(*request);228 request_size += count * sizeof(*gb_xfer);229 request_size += tx_size;230 231 /* Response consists only of incoming data */232 operation = gb_operation_create(connection, GB_SPI_TYPE_TRANSFER,233 request_size, rx_size, GFP_KERNEL);234 if (!operation)235 return NULL;236 237 request = operation->request->payload;238 request->count = cpu_to_le16(count);239 request->mode = dev->mode;240 request->chip_select = spi_get_chipselect(dev, 0);241 242 gb_xfer = &request->transfers[0];243 tx_data = gb_xfer + count; /* place tx data after last gb_xfer */244 245 /* Fill in the transfers array */246 xfer = spi->first_xfer;247 while (msg->state != GB_SPI_STATE_OP_DONE) {248 int xfer_delay;249 250 if (xfer == spi->last_xfer)251 xfer_len = spi->last_xfer_size;252 else253 xfer_len = xfer->len;254 255 /* make sure we do not timeout in a slow transfer */256 xfer_timeout = xfer_len * 8 * MSEC_PER_SEC / xfer->speed_hz;257 xfer_timeout += GB_OPERATION_TIMEOUT_DEFAULT;258 259 if (xfer_timeout > spi->op_timeout)260 spi->op_timeout = xfer_timeout;261 262 gb_xfer->speed_hz = cpu_to_le32(xfer->speed_hz);263 gb_xfer->len = cpu_to_le32(xfer_len);264 xfer_delay = spi_delay_to_ns(&xfer->delay, xfer) / 1000;265 xfer_delay = clamp_t(u16, xfer_delay, 0, U16_MAX);266 gb_xfer->delay_usecs = cpu_to_le16(xfer_delay);267 gb_xfer->cs_change = xfer->cs_change;268 gb_xfer->bits_per_word = xfer->bits_per_word;269 270 /* Copy tx data */271 if (xfer->tx_buf) {272 gb_xfer->xfer_flags |= GB_SPI_XFER_WRITE;273 memcpy(tx_data, xfer->tx_buf + spi->tx_xfer_offset,274 xfer_len);275 tx_data += xfer_len;276 }277 278 if (xfer->rx_buf)279 gb_xfer->xfer_flags |= GB_SPI_XFER_READ;280 281 if (xfer == spi->last_xfer) {282 if (!is_last_xfer_done(spi))283 gb_xfer->xfer_flags |= GB_SPI_XFER_INPROGRESS;284 msg->state = GB_SPI_STATE_OP_DONE;285 continue;286 }287 288 gb_xfer++;289 xfer = get_next_xfer(xfer, msg);290 }291 292 msg->actual_length += total_len;293 294 return operation;295}296 297static void gb_spi_decode_response(struct gb_spilib *spi,298 struct spi_message *msg,299 struct gb_spi_transfer_response *response)300{301 struct spi_transfer *xfer = spi->first_xfer;302 void *rx_data = response->data;303 u32 xfer_len;304 305 while (xfer) {306 /* Copy rx data */307 if (xfer->rx_buf) {308 if (xfer == spi->first_xfer)309 xfer_len = xfer->len - spi->rx_xfer_offset;310 else if (xfer == spi->last_xfer)311 xfer_len = spi->last_xfer_size;312 else313 xfer_len = xfer->len;314 315 memcpy(xfer->rx_buf + spi->rx_xfer_offset, rx_data,316 xfer_len);317 rx_data += xfer_len;318 }319 320 if (xfer == spi->last_xfer)321 break;322 323 xfer = list_next_entry(xfer, transfer_list);324 }325}326 327static int gb_spi_transfer_one_message(struct spi_controller *ctlr,328 struct spi_message *msg)329{330 struct gb_spilib *spi = spi_controller_get_devdata(ctlr);331 struct gb_connection *connection = spi->connection;332 struct gb_spi_transfer_response *response;333 struct gb_operation *operation;334 int ret = 0;335 336 spi->first_xfer = list_first_entry_or_null(&msg->transfers,337 struct spi_transfer,338 transfer_list);339 if (!spi->first_xfer) {340 ret = -ENOMEM;341 goto out;342 }343 344 msg->state = GB_SPI_STATE_MSG_IDLE;345 346 while (msg->state != GB_SPI_STATE_MSG_DONE &&347 msg->state != GB_SPI_STATE_MSG_ERROR) {348 operation = gb_spi_operation_create(spi, connection, msg);349 if (!operation) {350 msg->state = GB_SPI_STATE_MSG_ERROR;351 ret = -EINVAL;352 continue;353 }354 355 ret = gb_operation_request_send_sync_timeout(operation,356 spi->op_timeout);357 if (!ret) {358 response = operation->response->payload;359 if (response)360 gb_spi_decode_response(spi, msg, response);361 } else {362 dev_err(spi->parent,363 "transfer operation failed: %d\n", ret);364 msg->state = GB_SPI_STATE_MSG_ERROR;365 }366 367 gb_operation_put(operation);368 setup_next_xfer(spi, msg);369 }370 371out:372 msg->status = ret;373 clean_xfer_state(spi);374 spi_finalize_current_message(ctlr);375 376 return ret;377}378 379static int gb_spi_prepare_transfer_hardware(struct spi_controller *ctlr)380{381 struct gb_spilib *spi = spi_controller_get_devdata(ctlr);382 383 return spi->ops->prepare_transfer_hardware(spi->parent);384}385 386static int gb_spi_unprepare_transfer_hardware(struct spi_controller *ctlr)387{388 struct gb_spilib *spi = spi_controller_get_devdata(ctlr);389 390 spi->ops->unprepare_transfer_hardware(spi->parent);391 392 return 0;393}394 395static int gb_spi_setup(struct spi_device *spi)396{397 /* Nothing to do for now */398 return 0;399}400 401static void gb_spi_cleanup(struct spi_device *spi)402{403 /* Nothing to do for now */404}405 406/* Routines to get controller information */407 408/*409 * Map Greybus spi mode bits/flags/bpw into Linux ones.410 * All bits are same for now and so these macro's return same values.411 */412#define gb_spi_mode_map(mode) mode413#define gb_spi_flags_map(flags) flags414 415static int gb_spi_get_master_config(struct gb_spilib *spi)416{417 struct gb_spi_master_config_response response;418 u16 mode, flags;419 int ret;420 421 ret = gb_operation_sync(spi->connection, GB_SPI_TYPE_MASTER_CONFIG,422 NULL, 0, &response, sizeof(response));423 if (ret < 0)424 return ret;425 426 mode = le16_to_cpu(response.mode);427 spi->mode = gb_spi_mode_map(mode);428 429 flags = le16_to_cpu(response.flags);430 spi->flags = gb_spi_flags_map(flags);431 432 spi->bits_per_word_mask = le32_to_cpu(response.bits_per_word_mask);433 spi->num_chipselect = response.num_chipselect;434 435 spi->min_speed_hz = le32_to_cpu(response.min_speed_hz);436 spi->max_speed_hz = le32_to_cpu(response.max_speed_hz);437 438 return 0;439}440 441static int gb_spi_setup_device(struct gb_spilib *spi, u8 cs)442{443 struct spi_controller *ctlr = get_controller_from_spi(spi);444 struct gb_spi_device_config_request request;445 struct gb_spi_device_config_response response;446 struct spi_board_info spi_board = { {0} };447 struct spi_device *spidev;448 int ret;449 u8 dev_type;450 451 request.chip_select = cs;452 453 ret = gb_operation_sync(spi->connection, GB_SPI_TYPE_DEVICE_CONFIG,454 &request, sizeof(request),455 &response, sizeof(response));456 if (ret < 0)457 return ret;458 459 dev_type = response.device_type;460 461 if (dev_type == GB_SPI_SPI_DEV)462 strscpy(spi_board.modalias, "spidev",463 sizeof(spi_board.modalias));464 else if (dev_type == GB_SPI_SPI_NOR)465 strscpy(spi_board.modalias, "spi-nor",466 sizeof(spi_board.modalias));467 else if (dev_type == GB_SPI_SPI_MODALIAS)468 memcpy(spi_board.modalias, response.name,469 sizeof(spi_board.modalias));470 else471 return -EINVAL;472 473 spi_board.mode = le16_to_cpu(response.mode);474 spi_board.bus_num = ctlr->bus_num;475 spi_board.chip_select = cs;476 spi_board.max_speed_hz = le32_to_cpu(response.max_speed_hz);477 478 spidev = spi_new_device(ctlr, &spi_board);479 if (!spidev)480 return -EINVAL;481 482 return 0;483}484 485int gb_spilib_master_init(struct gb_connection *connection, struct device *dev,486 struct spilib_ops *ops)487{488 struct gb_spilib *spi;489 struct spi_controller *ctlr;490 int ret;491 u8 i;492 493 /* Allocate host with space for data */494 ctlr = spi_alloc_host(dev, sizeof(*spi));495 if (!ctlr) {496 dev_err(dev, "cannot alloc SPI host\n");497 return -ENOMEM;498 }499 500 spi = spi_controller_get_devdata(ctlr);501 spi->connection = connection;502 gb_connection_set_data(connection, ctlr);503 spi->parent = dev;504 spi->ops = ops;505 506 /* get controller configuration */507 ret = gb_spi_get_master_config(spi);508 if (ret)509 goto exit_spi_put;510 511 ctlr->bus_num = -1; /* Allow spi-core to allocate it dynamically */512 ctlr->num_chipselect = spi->num_chipselect;513 ctlr->mode_bits = spi->mode;514 ctlr->flags = spi->flags;515 ctlr->bits_per_word_mask = spi->bits_per_word_mask;516 517 /* Attach methods */518 ctlr->cleanup = gb_spi_cleanup;519 ctlr->setup = gb_spi_setup;520 ctlr->transfer_one_message = gb_spi_transfer_one_message;521 522 if (ops && ops->prepare_transfer_hardware) {523 ctlr->prepare_transfer_hardware =524 gb_spi_prepare_transfer_hardware;525 }526 527 if (ops && ops->unprepare_transfer_hardware) {528 ctlr->unprepare_transfer_hardware =529 gb_spi_unprepare_transfer_hardware;530 }531 532 ctlr->auto_runtime_pm = true;533 534 ret = spi_register_controller(ctlr);535 if (ret < 0)536 goto exit_spi_put;537 538 /* now, fetch the devices configuration */539 for (i = 0; i < spi->num_chipselect; i++) {540 ret = gb_spi_setup_device(spi, i);541 if (ret < 0) {542 dev_err(dev, "failed to allocate spi device %d: %d\n",543 i, ret);544 goto exit_spi_unregister;545 }546 }547 548 return 0;549 550exit_spi_put:551 spi_controller_put(ctlr);552 553 return ret;554 555exit_spi_unregister:556 spi_unregister_controller(ctlr);557 558 return ret;559}560EXPORT_SYMBOL_GPL(gb_spilib_master_init);561 562void gb_spilib_master_exit(struct gb_connection *connection)563{564 struct spi_controller *ctlr = gb_connection_get_data(connection);565 566 spi_unregister_controller(ctlr);567}568EXPORT_SYMBOL_GPL(gb_spilib_master_exit);569 570MODULE_DESCRIPTION("Greybus SPI library");571MODULE_LICENSE("GPL v2");572