linux/drivers/iio/common/ssp_sensors/ssp_spi.c
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   1/*
   2 *  Copyright (C) 2014, Samsung Electronics Co. Ltd. All Rights Reserved.
   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 */
  15
  16#include "ssp.h"
  17
  18#define SSP_DEV (&data->spi->dev)
  19#define SSP_GET_MESSAGE_TYPE(data) (data & (3 << SSP_RW))
  20
  21/*
  22 * SSP -> AP Instruction
  23 * They tell what packet type can be expected. In the future there will
  24 * be less of them. BYPASS means common sensor packets with accel, gyro,
  25 * hrm etc. data. LIBRARY and META are mock-up's for now.
  26 */
  27#define SSP_MSG2AP_INST_BYPASS_DATA             0x37
  28#define SSP_MSG2AP_INST_LIBRARY_DATA            0x01
  29#define SSP_MSG2AP_INST_DEBUG_DATA              0x03
  30#define SSP_MSG2AP_INST_BIG_DATA                0x04
  31#define SSP_MSG2AP_INST_META_DATA               0x05
  32#define SSP_MSG2AP_INST_TIME_SYNC               0x06
  33#define SSP_MSG2AP_INST_RESET                   0x07
  34
  35#define SSP_UNIMPLEMENTED -1
  36
  37struct ssp_msg_header {
  38        u8 cmd;
  39        __le16 length;
  40        __le16 options;
  41        __le32 data;
  42} __attribute__((__packed__));
  43
  44struct ssp_msg {
  45        u16 length;
  46        u16 options;
  47        struct list_head list;
  48        struct completion *done;
  49        struct ssp_msg_header *h;
  50        char *buffer;
  51};
  52
  53static const int ssp_offset_map[SSP_SENSOR_MAX] = {
  54        [SSP_ACCELEROMETER_SENSOR] =            SSP_ACCELEROMETER_SIZE +
  55                                                SSP_TIME_SIZE,
  56        [SSP_GYROSCOPE_SENSOR] =                SSP_GYROSCOPE_SIZE +
  57                                                SSP_TIME_SIZE,
  58        [SSP_GEOMAGNETIC_UNCALIB_SENSOR] =      SSP_UNIMPLEMENTED,
  59        [SSP_GEOMAGNETIC_RAW] =                 SSP_UNIMPLEMENTED,
  60        [SSP_GEOMAGNETIC_SENSOR] =              SSP_UNIMPLEMENTED,
  61        [SSP_PRESSURE_SENSOR] =                 SSP_UNIMPLEMENTED,
  62        [SSP_GESTURE_SENSOR] =                  SSP_UNIMPLEMENTED,
  63        [SSP_PROXIMITY_SENSOR] =                SSP_UNIMPLEMENTED,
  64        [SSP_TEMPERATURE_HUMIDITY_SENSOR] =     SSP_UNIMPLEMENTED,
  65        [SSP_LIGHT_SENSOR] =                    SSP_UNIMPLEMENTED,
  66        [SSP_PROXIMITY_RAW] =                   SSP_UNIMPLEMENTED,
  67        [SSP_ORIENTATION_SENSOR] =              SSP_UNIMPLEMENTED,
  68        [SSP_STEP_DETECTOR] =                   SSP_UNIMPLEMENTED,
  69        [SSP_SIG_MOTION_SENSOR] =               SSP_UNIMPLEMENTED,
  70        [SSP_GYRO_UNCALIB_SENSOR] =             SSP_UNIMPLEMENTED,
  71        [SSP_GAME_ROTATION_VECTOR] =            SSP_UNIMPLEMENTED,
  72        [SSP_ROTATION_VECTOR] =                 SSP_UNIMPLEMENTED,
  73        [SSP_STEP_COUNTER] =                    SSP_UNIMPLEMENTED,
  74        [SSP_BIO_HRM_RAW] =                     SSP_BIO_HRM_RAW_SIZE +
  75                                                SSP_TIME_SIZE,
  76        [SSP_BIO_HRM_RAW_FAC] =                 SSP_BIO_HRM_RAW_FAC_SIZE +
  77                                                SSP_TIME_SIZE,
  78        [SSP_BIO_HRM_LIB] =                     SSP_BIO_HRM_LIB_SIZE +
  79                                                SSP_TIME_SIZE,
  80};
  81
  82#define SSP_HEADER_SIZE         (sizeof(struct ssp_msg_header))
  83#define SSP_HEADER_SIZE_ALIGNED (ALIGN(SSP_HEADER_SIZE, 4))
  84
  85static struct ssp_msg *ssp_create_msg(u8 cmd, u16 len, u16 opt, u32 data)
  86{
  87        struct ssp_msg_header h;
  88        struct ssp_msg *msg;
  89
  90        msg = kzalloc(sizeof(*msg), GFP_KERNEL);
  91        if (!msg)
  92                return NULL;
  93
  94        h.cmd = cmd;
  95        h.length = cpu_to_le16(len);
  96        h.options = cpu_to_le16(opt);
  97        h.data = cpu_to_le32(data);
  98
  99        msg->buffer = kzalloc(SSP_HEADER_SIZE_ALIGNED + len,
 100                              GFP_KERNEL | GFP_DMA);
 101        if (!msg->buffer) {
 102                kfree(msg);
 103                return NULL;
 104        }
 105
 106        msg->length = len;
 107        msg->options = opt;
 108
 109        memcpy(msg->buffer, &h, SSP_HEADER_SIZE);
 110
 111        return msg;
 112}
 113
 114/*
 115 * It is a bit heavy to do it this way but often the function is used to compose
 116 * the message from smaller chunks which are placed on the stack.  Often the
 117 * chunks are small so memcpy should be optimalized.
 118 */
 119static inline void ssp_fill_buffer(struct ssp_msg *m, unsigned int offset,
 120                                   const void *src, unsigned int len)
 121{
 122        memcpy(&m->buffer[SSP_HEADER_SIZE_ALIGNED + offset], src, len);
 123}
 124
 125static inline void ssp_get_buffer(struct ssp_msg *m, unsigned int offset,
 126                                  void *dest, unsigned int len)
 127{
 128        memcpy(dest, &m->buffer[SSP_HEADER_SIZE_ALIGNED + offset],  len);
 129}
 130
 131#define SSP_GET_BUFFER_AT_INDEX(m, index) \
 132        (m->buffer[SSP_HEADER_SIZE_ALIGNED + index])
 133#define SSP_SET_BUFFER_AT_INDEX(m, index, val) \
 134        (m->buffer[SSP_HEADER_SIZE_ALIGNED + index] = val)
 135
 136static void ssp_clean_msg(struct ssp_msg *m)
 137{
 138        kfree(m->buffer);
 139        kfree(m);
 140}
 141
 142static int ssp_print_mcu_debug(char *data_frame, int *data_index,
 143                               int received_len)
 144{
 145        int length = data_frame[(*data_index)++];
 146
 147        if (length > received_len - *data_index || length <= 0) {
 148                ssp_dbg("[SSP]: MSG From MCU-invalid debug length(%d/%d)\n",
 149                        length, received_len);
 150                return length ? length : -EPROTO;
 151        }
 152
 153        ssp_dbg("[SSP]: MSG From MCU - %s\n", &data_frame[*data_index]);
 154
 155        *data_index += length;
 156
 157        return 0;
 158}
 159
 160/*
 161 * It was designed that way - additional lines to some kind of handshake,
 162 * please do not ask why - only the firmware guy can know it.
 163 */
 164static int ssp_check_lines(struct ssp_data *data, bool state)
 165{
 166        int delay_cnt = 0;
 167
 168        gpio_set_value_cansleep(data->ap_mcu_gpio, state);
 169
 170        while (gpio_get_value_cansleep(data->mcu_ap_gpio) != state) {
 171                usleep_range(3000, 3500);
 172
 173                if (data->shut_down || delay_cnt++ > 500) {
 174                        dev_err(SSP_DEV, "%s:timeout, hw ack wait fail %d\n",
 175                                __func__, state);
 176
 177                        if (!state)
 178                                gpio_set_value_cansleep(data->ap_mcu_gpio, 1);
 179
 180                        return -ETIMEDOUT;
 181                }
 182        }
 183
 184        return 0;
 185}
 186
 187static int ssp_do_transfer(struct ssp_data *data, struct ssp_msg *msg,
 188                           struct completion *done, int timeout)
 189{
 190        int status;
 191        /*
 192         * check if this is a short one way message or the whole transfer has
 193         * second part after an interrupt
 194         */
 195        const bool use_no_irq = msg->length == 0;
 196
 197        if (data->shut_down)
 198                return -EPERM;
 199
 200        msg->done = done;
 201
 202        mutex_lock(&data->comm_lock);
 203
 204        status = ssp_check_lines(data, false);
 205        if (status < 0)
 206                goto _error_locked;
 207
 208        status = spi_write(data->spi, msg->buffer, SSP_HEADER_SIZE);
 209        if (status < 0) {
 210                gpio_set_value_cansleep(data->ap_mcu_gpio, 1);
 211                dev_err(SSP_DEV, "%s spi_write fail\n", __func__);
 212                goto _error_locked;
 213        }
 214
 215        if (!use_no_irq) {
 216                mutex_lock(&data->pending_lock);
 217                list_add_tail(&msg->list, &data->pending_list);
 218                mutex_unlock(&data->pending_lock);
 219        }
 220
 221        status = ssp_check_lines(data, true);
 222        if (status < 0) {
 223                if (!use_no_irq) {
 224                        mutex_lock(&data->pending_lock);
 225                        list_del(&msg->list);
 226                        mutex_unlock(&data->pending_lock);
 227                }
 228                goto _error_locked;
 229        }
 230
 231        mutex_unlock(&data->comm_lock);
 232
 233        if (!use_no_irq && done)
 234                if (wait_for_completion_timeout(done,
 235                                                msecs_to_jiffies(timeout)) ==
 236                    0) {
 237                        mutex_lock(&data->pending_lock);
 238                        list_del(&msg->list);
 239                        mutex_unlock(&data->pending_lock);
 240
 241                        data->timeout_cnt++;
 242                        return -ETIMEDOUT;
 243                }
 244
 245        return 0;
 246
 247_error_locked:
 248        mutex_unlock(&data->comm_lock);
 249        data->timeout_cnt++;
 250        return status;
 251}
 252
 253static inline int ssp_spi_sync_command(struct ssp_data *data,
 254                                       struct ssp_msg *msg)
 255{
 256        return ssp_do_transfer(data, msg, NULL, 0);
 257}
 258
 259static int ssp_spi_sync(struct ssp_data *data, struct ssp_msg *msg,
 260                        int timeout)
 261{
 262        DECLARE_COMPLETION_ONSTACK(done);
 263
 264        if (WARN_ON(!msg->length))
 265                return -EPERM;
 266
 267        return ssp_do_transfer(data, msg, &done, timeout);
 268}
 269
 270static int ssp_handle_big_data(struct ssp_data *data, char *dataframe, int *idx)
 271{
 272        /* mock-up, it will be changed with adding another sensor types */
 273        *idx += 8;
 274        return 0;
 275}
 276
 277static int ssp_parse_dataframe(struct ssp_data *data, char *dataframe, int len)
 278{
 279        int idx, sd;
 280        struct ssp_sensor_data *spd;
 281        struct iio_dev **indio_devs = data->sensor_devs;
 282
 283        for (idx = 0; idx < len;) {
 284                switch (dataframe[idx++]) {
 285                case SSP_MSG2AP_INST_BYPASS_DATA:
 286                        sd = dataframe[idx++];
 287                        if (sd < 0 || sd >= SSP_SENSOR_MAX) {
 288                                dev_err(SSP_DEV,
 289                                        "Mcu data frame1 error %d\n", sd);
 290                                return -EPROTO;
 291                        }
 292
 293                        if (indio_devs[sd]) {
 294                                spd = iio_priv(indio_devs[sd]);
 295                                if (spd->process_data)
 296                                        spd->process_data(indio_devs[sd],
 297                                                          &dataframe[idx],
 298                                                          data->timestamp);
 299                        } else {
 300                                dev_err(SSP_DEV, "no client for frame\n");
 301                        }
 302
 303                        idx += ssp_offset_map[sd];
 304                        break;
 305                case SSP_MSG2AP_INST_DEBUG_DATA:
 306                        sd = ssp_print_mcu_debug(dataframe, &idx, len);
 307                        if (sd) {
 308                                dev_err(SSP_DEV,
 309                                        "Mcu data frame3 error %d\n", sd);
 310                                return sd;
 311                        }
 312                        break;
 313                case SSP_MSG2AP_INST_LIBRARY_DATA:
 314                        idx += len;
 315                        break;
 316                case SSP_MSG2AP_INST_BIG_DATA:
 317                        ssp_handle_big_data(data, dataframe, &idx);
 318                        break;
 319                case SSP_MSG2AP_INST_TIME_SYNC:
 320                        data->time_syncing = true;
 321                        break;
 322                case SSP_MSG2AP_INST_RESET:
 323                        ssp_queue_ssp_refresh_task(data, 0);
 324                        break;
 325                }
 326        }
 327
 328        if (data->time_syncing)
 329                data->timestamp = ktime_get_real_ns();
 330
 331        return 0;
 332}
 333
 334/* threaded irq */
 335int ssp_irq_msg(struct ssp_data *data)
 336{
 337        bool found = false;
 338        char *buffer;
 339        u8 msg_type;
 340        int ret;
 341        u16 length, msg_options;
 342        struct ssp_msg *msg, *n;
 343
 344        ret = spi_read(data->spi, data->header_buffer, SSP_HEADER_BUFFER_SIZE);
 345        if (ret < 0) {
 346                dev_err(SSP_DEV, "header read fail\n");
 347                return ret;
 348        }
 349
 350        length = le16_to_cpu(data->header_buffer[1]);
 351        msg_options = le16_to_cpu(data->header_buffer[0]);
 352
 353        if (length == 0) {
 354                dev_err(SSP_DEV, "length received from mcu is 0\n");
 355                return -EINVAL;
 356        }
 357
 358        msg_type = SSP_GET_MESSAGE_TYPE(msg_options);
 359
 360        switch (msg_type) {
 361        case SSP_AP2HUB_READ:
 362        case SSP_AP2HUB_WRITE:
 363                /*
 364                 * this is a small list, a few elements - the packets can be
 365                 * received with no order
 366                 */
 367                mutex_lock(&data->pending_lock);
 368                list_for_each_entry_safe(msg, n, &data->pending_list, list) {
 369                        if (msg->options == msg_options) {
 370                                list_del(&msg->list);
 371                                found = true;
 372                                break;
 373                        }
 374                }
 375
 376                if (!found) {
 377                        /*
 378                         * here can be implemented dead messages handling
 379                         * but the slave should not send such ones - it is to
 380                         * check but let's handle this
 381                         */
 382                        buffer = kmalloc(length, GFP_KERNEL | GFP_DMA);
 383                        if (!buffer) {
 384                                ret = -ENOMEM;
 385                                goto _unlock;
 386                        }
 387
 388                        /* got dead packet so it is always an error */
 389                        ret = spi_read(data->spi, buffer, length);
 390                        if (ret >= 0)
 391                                ret = -EPROTO;
 392
 393                        kfree(buffer);
 394
 395                        dev_err(SSP_DEV, "No match error %x\n",
 396                                msg_options);
 397
 398                        goto _unlock;
 399                }
 400
 401                if (msg_type == SSP_AP2HUB_READ)
 402                        ret = spi_read(data->spi,
 403                                       &msg->buffer[SSP_HEADER_SIZE_ALIGNED],
 404                                       msg->length);
 405
 406                if (msg_type == SSP_AP2HUB_WRITE) {
 407                        ret = spi_write(data->spi,
 408                                        &msg->buffer[SSP_HEADER_SIZE_ALIGNED],
 409                                        msg->length);
 410                        if (msg_options & SSP_AP2HUB_RETURN) {
 411                                msg->options =
 412                                        SSP_AP2HUB_READ | SSP_AP2HUB_RETURN;
 413                                msg->length = 1;
 414
 415                                list_add_tail(&msg->list, &data->pending_list);
 416                                goto _unlock;
 417                        }
 418                }
 419
 420                if (msg->done)
 421                        if (!completion_done(msg->done))
 422                                complete(msg->done);
 423_unlock:
 424                mutex_unlock(&data->pending_lock);
 425                break;
 426        case SSP_HUB2AP_WRITE:
 427                buffer = kzalloc(length, GFP_KERNEL | GFP_DMA);
 428                if (!buffer)
 429                        return -ENOMEM;
 430
 431                ret = spi_read(data->spi, buffer, length);
 432                if (ret < 0) {
 433                        dev_err(SSP_DEV, "spi read fail\n");
 434                        kfree(buffer);
 435                        break;
 436                }
 437
 438                ret = ssp_parse_dataframe(data, buffer, length);
 439
 440                kfree(buffer);
 441                break;
 442
 443        default:
 444                dev_err(SSP_DEV, "unknown msg type\n");
 445                return -EPROTO;
 446        }
 447
 448        return ret;
 449}
 450
 451void ssp_clean_pending_list(struct ssp_data *data)
 452{
 453        struct ssp_msg *msg, *n;
 454
 455        mutex_lock(&data->pending_lock);
 456        list_for_each_entry_safe(msg, n, &data->pending_list, list) {
 457                list_del(&msg->list);
 458
 459                if (msg->done)
 460                        if (!completion_done(msg->done))
 461                                complete(msg->done);
 462        }
 463        mutex_unlock(&data->pending_lock);
 464}
 465
 466int ssp_command(struct ssp_data *data, char command, int arg)
 467{
 468        int ret;
 469        struct ssp_msg *msg;
 470
 471        msg = ssp_create_msg(command, 0, SSP_AP2HUB_WRITE, arg);
 472        if (!msg)
 473                return -ENOMEM;
 474
 475        ssp_dbg("%s - command 0x%x %d\n", __func__, command, arg);
 476
 477        ret = ssp_spi_sync_command(data, msg);
 478        ssp_clean_msg(msg);
 479
 480        return ret;
 481}
 482
 483int ssp_send_instruction(struct ssp_data *data, u8 inst, u8 sensor_type,
 484                         u8 *send_buf, u8 length)
 485{
 486        int ret;
 487        struct ssp_msg *msg;
 488
 489        if (data->fw_dl_state == SSP_FW_DL_STATE_DOWNLOADING) {
 490                dev_err(SSP_DEV, "%s - Skip Inst! DL state = %d\n",
 491                        __func__, data->fw_dl_state);
 492                return -EBUSY;
 493        } else if (!(data->available_sensors & BIT(sensor_type)) &&
 494                   (inst <= SSP_MSG2SSP_INST_CHANGE_DELAY)) {
 495                dev_err(SSP_DEV, "%s - Bypass Inst Skip! - %u\n",
 496                        __func__, sensor_type);
 497                return -EIO; /* just fail */
 498        }
 499
 500        msg = ssp_create_msg(inst, length + 2, SSP_AP2HUB_WRITE, 0);
 501        if (!msg)
 502                return -ENOMEM;
 503
 504        ssp_fill_buffer(msg, 0, &sensor_type, 1);
 505        ssp_fill_buffer(msg, 1, send_buf, length);
 506
 507        ssp_dbg("%s - Inst = 0x%x, Sensor Type = 0x%x, data = %u\n",
 508                __func__, inst, sensor_type, send_buf[1]);
 509
 510        ret = ssp_spi_sync(data, msg, 1000);
 511        ssp_clean_msg(msg);
 512
 513        return ret;
 514}
 515
 516int ssp_get_chipid(struct ssp_data *data)
 517{
 518        int ret;
 519        char buffer;
 520        struct ssp_msg *msg;
 521
 522        msg = ssp_create_msg(SSP_MSG2SSP_AP_WHOAMI, 1, SSP_AP2HUB_READ, 0);
 523        if (!msg)
 524                return -ENOMEM;
 525
 526        ret = ssp_spi_sync(data, msg, 1000);
 527
 528        buffer = SSP_GET_BUFFER_AT_INDEX(msg, 0);
 529
 530        ssp_clean_msg(msg);
 531
 532        return ret < 0 ? ret : buffer;
 533}
 534
 535int ssp_set_magnetic_matrix(struct ssp_data *data)
 536{
 537        int ret;
 538        struct ssp_msg *msg;
 539
 540        msg = ssp_create_msg(SSP_MSG2SSP_AP_SET_MAGNETIC_STATIC_MATRIX,
 541                             data->sensorhub_info->mag_length, SSP_AP2HUB_WRITE,
 542                             0);
 543        if (!msg)
 544                return -ENOMEM;
 545
 546        ssp_fill_buffer(msg, 0, data->sensorhub_info->mag_table,
 547                        data->sensorhub_info->mag_length);
 548
 549        ret = ssp_spi_sync(data, msg, 1000);
 550        ssp_clean_msg(msg);
 551
 552        return ret;
 553}
 554
 555unsigned int ssp_get_sensor_scanning_info(struct ssp_data *data)
 556{
 557        int ret;
 558        __le32 result;
 559        u32 cpu_result = 0;
 560
 561        struct ssp_msg *msg = ssp_create_msg(SSP_MSG2SSP_AP_SENSOR_SCANNING, 4,
 562                                             SSP_AP2HUB_READ, 0);
 563        if (!msg)
 564                return 0;
 565
 566        ret = ssp_spi_sync(data, msg, 1000);
 567        if (ret < 0) {
 568                dev_err(SSP_DEV, "%s - spi read fail %d\n", __func__, ret);
 569                goto _exit;
 570        }
 571
 572        ssp_get_buffer(msg, 0, &result, 4);
 573        cpu_result = le32_to_cpu(result);
 574
 575        dev_info(SSP_DEV, "%s state: 0x%08x\n", __func__, cpu_result);
 576
 577_exit:
 578        ssp_clean_msg(msg);
 579        return cpu_result;
 580}
 581
 582unsigned int ssp_get_firmware_rev(struct ssp_data *data)
 583{
 584        int ret;
 585        __le32 result;
 586
 587        struct ssp_msg *msg = ssp_create_msg(SSP_MSG2SSP_AP_FIRMWARE_REV, 4,
 588                                             SSP_AP2HUB_READ, 0);
 589        if (!msg)
 590                return SSP_INVALID_REVISION;
 591
 592        ret = ssp_spi_sync(data, msg, 1000);
 593        if (ret < 0) {
 594                dev_err(SSP_DEV, "%s - transfer fail %d\n", __func__, ret);
 595                ret = SSP_INVALID_REVISION;
 596                goto _exit;
 597        }
 598
 599        ssp_get_buffer(msg, 0, &result, 4);
 600        ret = le32_to_cpu(result);
 601
 602_exit:
 603        ssp_clean_msg(msg);
 604        return ret;
 605}
 606