drivers/gpu/drm/drm_mipi_dsi.c

   1 /*
   2  * MIPI DSI Bus
   3  *
   4  * Copyright (C) 2012-2013, Samsung Electronics, Co., Ltd.
   5  * Andrzej Hajda <a.hajda@samsung.com>
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the
   9  * "Software"), to deal in the Software without restriction, including
  10  * without limitation the rights to use, copy, modify, merge, publish,
  11  * distribute, sub license, and/or sell copies of the Software, and to
  12  * permit persons to whom the Software is furnished to do so, subject to
  13  * the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the
  16  * next paragraph) shall be included in all copies or substantial portions
  17  * of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  22  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  23  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  24  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  25  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  */
  27
  28 #include <drm/drm_mipi_dsi.h>
  29
  30 #include <linux/device.h>
  31 #include <linux/module.h>
  32 #include <linux/of_device.h>
  33 #include <linux/pm_runtime.h>
  34 #include <linux/slab.h>
  35
  36 #include <video/mipi_display.h>
  37
  38 /**
  39  * DOC: dsi helpers
  40  *
  41  * These functions contain some common logic and helpers to deal with MIPI DSI
  42  * peripherals.
  43  *
  44  * Helpers are provided for a number of standard MIPI DSI command as well as a
  45  * subset of the MIPI DCS command set.
  46  */
  47
  48 static int mipi_dsi_device_match(struct device *dev, struct device_driver *drv)
  49 {
  50         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
  51
  52         /* attempt OF style match */
  53         if (of_driver_match_device(dev, drv))
  54                 return 1;
  55
  56         /* compare DSI device and driver names */
  57         if (!strcmp(dsi->name, drv->name))
  58                 return 1;
  59
  60         return 0;
  61 }
  62
  63 static int mipi_dsi_uevent(struct device *dev, struct kobj_uevent_env *env)
  64 {
  65         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
  66         int err;
  67
  68         err = of_device_uevent_modalias(dev, env);
  69         if (err != -ENODEV)
  70                 return err;
  71
  72         add_uevent_var(env, "MODALIAS=%s%s", MIPI_DSI_MODULE_PREFIX,
  73                        dsi->name);
  74
  75         return 0;
  76 }
  77
  78 static const struct dev_pm_ops mipi_dsi_device_pm_ops = {
  79         .runtime_suspend = pm_generic_runtime_suspend,
  80         .runtime_resume = pm_generic_runtime_resume,
  81         .suspend = pm_generic_suspend,
  82         .resume = pm_generic_resume,
  83         .freeze = pm_generic_freeze,
  84         .thaw = pm_generic_thaw,
  85         .poweroff = pm_generic_poweroff,
  86         .restore = pm_generic_restore,
  87 };
  88
  89 static struct bus_type mipi_dsi_bus_type = {
  90         .name = "mipi-dsi",
  91         .match = mipi_dsi_device_match,
  92         .uevent = mipi_dsi_uevent,
  93         .pm = &mipi_dsi_device_pm_ops,
  94 };
  95
  96 static int of_device_match(struct device *dev, void *data)
  97 {
  98         return dev->of_node == data;
  99 }
 100
 101 /**
 102  * of_find_mipi_dsi_device_by_node() - find the MIPI DSI device matching a
 103  *    device tree node
 104  * @np: device tree node
 105  *
 106  * Return: A pointer to the MIPI DSI device corresponding to @np or NULL if no
 107  *    such device exists (or has not been registered yet).
 108  */
 109 struct mipi_dsi_device *of_find_mipi_dsi_device_by_node(struct device_node *np)
 110 {
 111         struct device *dev;
 112
 113         dev = bus_find_device(&mipi_dsi_bus_type, NULL, np, of_device_match);
 114
 115         return dev ? to_mipi_dsi_device(dev) : NULL;
 116 }
 117 EXPORT_SYMBOL(of_find_mipi_dsi_device_by_node);
 118
 119 static void mipi_dsi_dev_release(struct device *dev)
 120 {
 121         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
 122
 123         of_node_put(dev->of_node);
 124         kfree(dsi);
 125 }
 126
 127 static const struct device_type mipi_dsi_device_type = {
 128         .release = mipi_dsi_dev_release,
 129 };
 130
 131 static struct mipi_dsi_device *mipi_dsi_device_alloc(struct mipi_dsi_host *host)
 132 {
 133         struct mipi_dsi_device *dsi;
 134
 135         dsi = kzalloc(sizeof(*dsi), GFP_KERNEL);
 136         if (!dsi)
 137                 return ERR_PTR(-ENOMEM);
 138
 139         dsi->host = host;
 140         dsi->dev.bus = &mipi_dsi_bus_type;
 141         dsi->dev.parent = host->dev;
 142         dsi->dev.type = &mipi_dsi_device_type;
 143
 144         device_initialize(&dsi->dev);
 145
 146         return dsi;
 147 }
 148
 149 static int mipi_dsi_device_add(struct mipi_dsi_device *dsi)
 150 {
 151         struct mipi_dsi_host *host = dsi->host;
 152
 153         dev_set_name(&dsi->dev, "%s.%d", dev_name(host->dev),  dsi->channel);
 154
 155         return device_add(&dsi->dev);
 156 }
 157
 158 #if IS_ENABLED(CONFIG_OF)
 159 static struct mipi_dsi_device *
 160 of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
 161 {
 162         struct device *dev = host->dev;
 163         struct mipi_dsi_device_info info = { };
 164         int ret;
 165         u32 reg;
 166
 167         if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) {
 168                 dev_err(dev, "modalias failure on %s\n", node->full_name);
 169                 return ERR_PTR(-EINVAL);
 170         }
 171
 172         ret = of_property_read_u32(node, "reg", &reg);
 173         if (ret) {
 174                 dev_err(dev, "device node %s has no valid reg property: %d\n",
 175                         node->full_name, ret);
 176                 return ERR_PTR(-EINVAL);
 177         }
 178
 179         info.channel = reg;
 180         info.node = of_node_get(node);
 181
 182         return mipi_dsi_device_register_full(host, &info);
 183 }
 184 #else
 185 static struct mipi_dsi_device *
 186 of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
 187 {
 188         return ERR_PTR(-ENODEV);
 189 }
 190 #endif
 191
 192 /**
 193  * mipi_dsi_device_register_full - create a MIPI DSI device
 194  * @host: DSI host to which this device is connected
 195  * @info: pointer to template containing DSI device information
 196  *
 197  * Create a MIPI DSI device by using the device information provided by
 198  * mipi_dsi_device_info template
 199  *
 200  * Returns:
 201  * A pointer to the newly created MIPI DSI device, or, a pointer encoded
 202  * with an error
 203  */
 204 struct mipi_dsi_device *
 205 mipi_dsi_device_register_full(struct mipi_dsi_host *host,
 206                               const struct mipi_dsi_device_info *info)
 207 {
 208         struct mipi_dsi_device *dsi;
 209         struct device *dev = host->dev;
 210         int ret;
 211
 212         if (!info) {
 213                 dev_err(dev, "invalid mipi_dsi_device_info pointer\n");
 214                 return ERR_PTR(-EINVAL);
 215         }
 216
 217         if (info->channel > 3) {
 218                 dev_err(dev, "invalid virtual channel: %u\n", info->channel);
 219                 return ERR_PTR(-EINVAL);
 220         }
 221
 222         dsi = mipi_dsi_device_alloc(host);
 223         if (IS_ERR(dsi)) {
 224                 dev_err(dev, "failed to allocate DSI device %ld\n",
 225                         PTR_ERR(dsi));
 226                 return dsi;
 227         }
 228
 229         dsi->dev.of_node = info->node;
 230         dsi->channel = info->channel;
 231         strlcpy(dsi->name, info->type, sizeof(dsi->name));
 232
 233         ret = mipi_dsi_device_add(dsi);
 234         if (ret) {
 235                 dev_err(dev, "failed to add DSI device %d\n", ret);
 236                 kfree(dsi);
 237                 return ERR_PTR(ret);
 238         }
 239
 240         return dsi;
 241 }
 242 EXPORT_SYMBOL(mipi_dsi_device_register_full);
 243
 244 /**
 245  * mipi_dsi_device_unregister - unregister MIPI DSI device
 246  * @dsi: DSI peripheral device
 247  */
 248 void mipi_dsi_device_unregister(struct mipi_dsi_device *dsi)
 249 {
 250         device_unregister(&dsi->dev);
 251 }
 252 EXPORT_SYMBOL(mipi_dsi_device_unregister);
 253
 254 static DEFINE_MUTEX(host_lock);
 255 static LIST_HEAD(host_list);
 256
 257 /**
 258  * of_find_mipi_dsi_host_by_node() - find the MIPI DSI host matching a
 259  *                                   device tree node
 260  * @node: device tree node
 261  *
 262  * Returns:
 263  * A pointer to the MIPI DSI host corresponding to @node or NULL if no
 264  * such device exists (or has not been registered yet).
 265  */
 266 struct mipi_dsi_host *of_find_mipi_dsi_host_by_node(struct device_node *node)
 267 {
 268         struct mipi_dsi_host *host;
 269
 270         mutex_lock(&host_lock);
 271
 272         list_for_each_entry(host, &host_list, list) {
 273                 if (host->dev->of_node == node) {
 274                         mutex_unlock(&host_lock);
 275                         return host;
 276                 }
 277         }
 278
 279         mutex_unlock(&host_lock);
 280
 281         return NULL;
 282 }
 283 EXPORT_SYMBOL(of_find_mipi_dsi_host_by_node);
 284
 285 int mipi_dsi_host_register(struct mipi_dsi_host *host)
 286 {
 287         struct device_node *node;
 288
 289         for_each_available_child_of_node(host->dev->of_node, node) {
 290                 /* skip nodes without reg property */
 291                 if (!of_find_property(node, "reg", NULL))
 292                         continue;
 293                 of_mipi_dsi_device_add(host, node);
 294         }
 295
 296         mutex_lock(&host_lock);
 297         list_add_tail(&host->list, &host_list);
 298         mutex_unlock(&host_lock);
 299
 300         return 0;
 301 }
 302 EXPORT_SYMBOL(mipi_dsi_host_register);
 303
 304 static int mipi_dsi_remove_device_fn(struct device *dev, void *priv)
 305 {
 306         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
 307
 308         mipi_dsi_device_unregister(dsi);
 309
 310         return 0;
 311 }
 312
 313 void mipi_dsi_host_unregister(struct mipi_dsi_host *host)
 314 {
 315         device_for_each_child(host->dev, NULL, mipi_dsi_remove_device_fn);
 316
 317         mutex_lock(&host_lock);
 318         list_del_init(&host->list);
 319         mutex_unlock(&host_lock);
 320 }
 321 EXPORT_SYMBOL(mipi_dsi_host_unregister);
 322
 323 /**
 324  * mipi_dsi_attach - attach a DSI device to its DSI host
 325  * @dsi: DSI peripheral
 326  */
 327 int mipi_dsi_attach(struct mipi_dsi_device *dsi)
 328 {
 329         const struct mipi_dsi_host_ops *ops = dsi->host->ops;
 330
 331         if (!ops || !ops->attach)
 332                 return -ENOSYS;
 333
 334         return ops->attach(dsi->host, dsi);
 335 }
 336 EXPORT_SYMBOL(mipi_dsi_attach);
 337
 338 /**
 339  * mipi_dsi_detach - detach a DSI device from its DSI host
 340  * @dsi: DSI peripheral
 341  */
 342 int mipi_dsi_detach(struct mipi_dsi_device *dsi)
 343 {
 344         const struct mipi_dsi_host_ops *ops = dsi->host->ops;
 345
 346         if (!ops || !ops->detach)
 347                 return -ENOSYS;
 348
 349         return ops->detach(dsi->host, dsi);
 350 }
 351 EXPORT_SYMBOL(mipi_dsi_detach);
 352
 353 static ssize_t mipi_dsi_device_transfer(struct mipi_dsi_device *dsi,
 354                                         struct mipi_dsi_msg *msg)
 355 {
 356         const struct mipi_dsi_host_ops *ops = dsi->host->ops;
 357
 358         if (!ops || !ops->transfer)
 359                 return -ENOSYS;
 360
 361         if (dsi->mode_flags & MIPI_DSI_MODE_LPM)
 362                 msg->flags |= MIPI_DSI_MSG_USE_LPM;
 363
 364         return ops->transfer(dsi->host, msg);
 365 }
 366
 367 /**
 368  * mipi_dsi_packet_format_is_short - check if a packet is of the short format
 369  * @type: MIPI DSI data type of the packet
 370  *
 371  * Return: true if the packet for the given data type is a short packet, false
 372  * otherwise.
 373  */
 374 bool mipi_dsi_packet_format_is_short(u8 type)
 375 {
 376         switch (type) {
 377         case MIPI_DSI_V_SYNC_START:
 378         case MIPI_DSI_V_SYNC_END:
 379         case MIPI_DSI_H_SYNC_START:
 380         case MIPI_DSI_H_SYNC_END:
 381         case MIPI_DSI_END_OF_TRANSMISSION:
 382         case MIPI_DSI_COLOR_MODE_OFF:
 383         case MIPI_DSI_COLOR_MODE_ON:
 384         case MIPI_DSI_SHUTDOWN_PERIPHERAL:
 385         case MIPI_DSI_TURN_ON_PERIPHERAL:
 386         case MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM:
 387         case MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM:
 388         case MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM:
 389         case MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM:
 390         case MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM:
 391         case MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM:
 392         case MIPI_DSI_DCS_SHORT_WRITE:
 393         case MIPI_DSI_DCS_SHORT_WRITE_PARAM:
 394         case MIPI_DSI_DCS_READ:
 395         case MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE:
 396                 return true;
 397         }
 398
 399         return false;
 400 }
 401 EXPORT_SYMBOL(mipi_dsi_packet_format_is_short);
 402
 403 /**
 404  * mipi_dsi_packet_format_is_long - check if a packet is of the long format
 405  * @type: MIPI DSI data type of the packet
 406  *
 407  * Return: true if the packet for the given data type is a long packet, false
 408  * otherwise.
 409  */
 410 bool mipi_dsi_packet_format_is_long(u8 type)
 411 {
 412         switch (type) {
 413         case MIPI_DSI_NULL_PACKET:
 414         case MIPI_DSI_BLANKING_PACKET:
 415         case MIPI_DSI_GENERIC_LONG_WRITE:
 416         case MIPI_DSI_DCS_LONG_WRITE:
 417         case MIPI_DSI_LOOSELY_PACKED_PIXEL_STREAM_YCBCR20:
 418         case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR24:
 419         case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR16:
 420         case MIPI_DSI_PACKED_PIXEL_STREAM_30:
 421         case MIPI_DSI_PACKED_PIXEL_STREAM_36:
 422         case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR12:
 423         case MIPI_DSI_PACKED_PIXEL_STREAM_16:
 424         case MIPI_DSI_PACKED_PIXEL_STREAM_18:
 425         case MIPI_DSI_PIXEL_STREAM_3BYTE_18:
 426         case MIPI_DSI_PACKED_PIXEL_STREAM_24:
 427                 return true;
 428         }
 429
 430         return false;
 431 }
 432 EXPORT_SYMBOL(mipi_dsi_packet_format_is_long);
 433
 434 /**
 435  * mipi_dsi_create_packet - create a packet from a message according to the
 436  *     DSI protocol
 437  * @packet: pointer to a DSI packet structure
 438  * @msg: message to translate into a packet
 439  *
 440  * Return: 0 on success or a negative error code on failure.
 441  */
 442 int mipi_dsi_create_packet(struct mipi_dsi_packet *packet,
 443                            const struct mipi_dsi_msg *msg)
 444 {
 445         if (!packet || !msg)
 446                 return -EINVAL;
 447
 448         /* do some minimum sanity checking */
 449         if (!mipi_dsi_packet_format_is_short(msg->type) &&
 450             !mipi_dsi_packet_format_is_long(msg->type))
 451                 return -EINVAL;
 452
 453         if (msg->channel > 3)
 454                 return -EINVAL;
 455
 456         memset(packet, 0, sizeof(*packet));
 457         packet->header[0] = ((msg->channel & 0x3) << 6) | (msg->type & 0x3f);
 458
 459         /* TODO: compute ECC if hardware support is not available */
 460
 461         /*
 462          * Long write packets contain the word count in header bytes 1 and 2.
 463          * The payload follows the header and is word count bytes long.
 464          *
 465          * Short write packets encode up to two parameters in header bytes 1
 466          * and 2.
 467          */
 468         if (mipi_dsi_packet_format_is_long(msg->type)) {
 469                 packet->header[1] = (msg->tx_len >> 0) & 0xff;
 470                 packet->header[2] = (msg->tx_len >> 8) & 0xff;
 471
 472                 packet->payload_length = msg->tx_len;
 473                 packet->payload = msg->tx_buf;
 474         } else {
 475                 const u8 *tx = msg->tx_buf;
 476
 477                 packet->header[1] = (msg->tx_len > 0) ? tx[0] : 0;
 478                 packet->header[2] = (msg->tx_len > 1) ? tx[1] : 0;
 479         }
 480
 481         packet->size = sizeof(packet->header) + packet->payload_length;
 482
 483         return 0;
 484 }
 485 EXPORT_SYMBOL(mipi_dsi_create_packet);
 486
 487 /**
 488  * mipi_dsi_shutdown_peripheral() - sends a Shutdown Peripheral command
 489  * @dsi: DSI peripheral device
 490  *
 491  * Return: 0 on success or a negative error code on failure.
 492  */
 493 int mipi_dsi_shutdown_peripheral(struct mipi_dsi_device *dsi)
 494 {
 495         struct mipi_dsi_msg msg = {
 496                 .channel = dsi->channel,
 497                 .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
 498                 .tx_buf = (u8 [2]) { 0, 0 },
 499                 .tx_len = 2,
 500         };
 501
 502         return mipi_dsi_device_transfer(dsi, &msg);
 503 }
 504 EXPORT_SYMBOL(mipi_dsi_shutdown_peripheral);
 505
 506 /**
 507  * mipi_dsi_turn_on_peripheral() - sends a Turn On Peripheral command
 508  * @dsi: DSI peripheral device
 509  *
 510  * Return: 0 on success or a negative error code on failure.
 511  */
 512 int mipi_dsi_turn_on_peripheral(struct mipi_dsi_device *dsi)
 513 {
 514         struct mipi_dsi_msg msg = {
 515                 .channel = dsi->channel,
 516                 .type = MIPI_DSI_TURN_ON_PERIPHERAL,
 517                 .tx_buf = (u8 [2]) { 0, 0 },
 518                 .tx_len = 2,
 519         };
 520
 521         return mipi_dsi_device_transfer(dsi, &msg);
 522 }
 523 EXPORT_SYMBOL(mipi_dsi_turn_on_peripheral);
 524
 525 /*
 526  * mipi_dsi_set_maximum_return_packet_size() - specify the maximum size of the
 527  *    the payload in a long packet transmitted from the peripheral back to the
 528  *    host processor
 529  * @dsi: DSI peripheral device
 530  * @value: the maximum size of the payload
 531  *
 532  * Return: 0 on success or a negative error code on failure.
 533  */
 534 int mipi_dsi_set_maximum_return_packet_size(struct mipi_dsi_device *dsi,
 535                                             u16 value)
 536 {
 537         u8 tx[2] = { value & 0xff, value >> 8 };
 538         struct mipi_dsi_msg msg = {
 539                 .channel = dsi->channel,
 540                 .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
 541                 .tx_len = sizeof(tx),
 542                 .tx_buf = tx,
 543         };
 544
 545         return mipi_dsi_device_transfer(dsi, &msg);
 546 }
 547 EXPORT_SYMBOL(mipi_dsi_set_maximum_return_packet_size);
 548
 549 /**
 550  * mipi_dsi_generic_write() - transmit data using a generic write packet
 551  * @dsi: DSI peripheral device
 552  * @payload: buffer containing the payload
 553  * @size: size of payload buffer
 554  *
 555  * This function will automatically choose the right data type depending on
 556  * the payload length.
 557  *
 558  * Return: The number of bytes transmitted on success or a negative error code
 559  * on failure.
 560  */
 561 ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload,
 562                                size_t size)
 563 {
 564         struct mipi_dsi_msg msg = {
 565                 .channel = dsi->channel,
 566                 .tx_buf = payload,
 567                 .tx_len = size
 568         };
 569
 570         switch (size) {
 571         case 0:
 572                 msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
 573                 break;
 574
 575         case 1:
 576                 msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
 577                 break;
 578
 579         case 2:
 580                 msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
 581                 break;
 582
 583         default:
 584                 msg.type = MIPI_DSI_GENERIC_LONG_WRITE;
 585                 break;
 586         }
 587
 588         return mipi_dsi_device_transfer(dsi, &msg);
 589 }
 590 EXPORT_SYMBOL(mipi_dsi_generic_write);
 591
 592 /**
 593  * mipi_dsi_generic_read() - receive data using a generic read packet
 594  * @dsi: DSI peripheral device
 595  * @params: buffer containing the request parameters
 596  * @num_params: number of request parameters
 597  * @data: buffer in which to return the received data
 598  * @size: size of receive buffer
 599  *
 600  * This function will automatically choose the right data type depending on
 601  * the number of parameters passed in.
 602  *
 603  * Return: The number of bytes successfully read or a negative error code on
 604  * failure.
 605  */
 606 ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params,
 607                               size_t num_params, void *data, size_t size)
 608 {
 609         struct mipi_dsi_msg msg = {
 610                 .channel = dsi->channel,
 611                 .tx_len = num_params,
 612                 .tx_buf = params,
 613                 .rx_len = size,
 614                 .rx_buf = data
 615         };
 616
 617         switch (num_params) {
 618         case 0:
 619                 msg.type = MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM;
 620                 break;
 621
 622         case 1:
 623                 msg.type = MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM;
 624                 break;
 625
 626         case 2:
 627                 msg.type = MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM;
 628                 break;
 629
 630         default:
 631                 return -EINVAL;
 632         }
 633
 634         return mipi_dsi_device_transfer(dsi, &msg);
 635 }
 636 EXPORT_SYMBOL(mipi_dsi_generic_read);
 637
 638 /**
 639  * mipi_dsi_dcs_write_buffer() - transmit a DCS command with payload
 640  * @dsi: DSI peripheral device
 641  * @data: buffer containing data to be transmitted
 642  * @len: size of transmission buffer
 643  *
 644  * This function will automatically choose the right data type depending on
 645  * the command payload length.
 646  *
 647  * Return: The number of bytes successfully transmitted or a negative error
 648  * code on failure.
 649  */
 650 ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi,
 651                                   const void *data, size_t len)
 652 {
 653         struct mipi_dsi_msg msg = {
 654                 .channel = dsi->channel,
 655                 .tx_buf = data,
 656                 .tx_len = len
 657         };
 658
 659         switch (len) {
 660         case 0:
 661                 return -EINVAL;
 662
 663         case 1:
 664                 msg.type = MIPI_DSI_DCS_SHORT_WRITE;
 665                 break;
 666
 667         case 2:
 668                 msg.type = MIPI_DSI_DCS_SHORT_WRITE_PARAM;
 669                 break;
 670
 671         default:
 672                 msg.type = MIPI_DSI_DCS_LONG_WRITE;
 673                 break;
 674         }
 675
 676         return mipi_dsi_device_transfer(dsi, &msg);
 677 }
 678 EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer);
 679
 680 /**
 681  * mipi_dsi_dcs_write() - send DCS write command
 682  * @dsi: DSI peripheral device
 683  * @cmd: DCS command
 684  * @data: buffer containing the command payload
 685  * @len: command payload length
 686  *
 687  * This function will automatically choose the right data type depending on
 688  * the command payload length.
 689  *
 690  * Return: The number of bytes successfully transmitted or a negative error
 691  * code on failure.
 692  */
 693 ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd,
 694                            const void *data, size_t len)
 695 {
 696         ssize_t err;
 697         size_t size;
 698         u8 *tx;
 699
 700         if (len > 0) {
 701                 size = 1 + len;
 702
 703                 tx = kmalloc(size, GFP_KERNEL);
 704                 if (!tx)
 705                         return -ENOMEM;
 706
 707                 /* concatenate the DCS command byte and the payload */
 708                 tx[0] = cmd;
 709                 memcpy(&tx[1], data, len);
 710         } else {
 711                 tx = &cmd;
 712                 size = 1;
 713         }
 714
 715         err = mipi_dsi_dcs_write_buffer(dsi, tx, size);
 716
 717         if (len > 0)
 718                 kfree(tx);
 719
 720         return err;
 721 }
 722 EXPORT_SYMBOL(mipi_dsi_dcs_write);
 723
 724 /**
 725  * mipi_dsi_dcs_read() - send DCS read request command
 726  * @dsi: DSI peripheral device
 727  * @cmd: DCS command
 728  * @data: buffer in which to receive data
 729  * @len: size of receive buffer
 730  *
 731  * Return: The number of bytes read or a negative error code on failure.
 732  */
 733 ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, u8 cmd, void *data,
 734                           size_t len)
 735 {
 736         struct mipi_dsi_msg msg = {
 737                 .channel = dsi->channel,
 738                 .type = MIPI_DSI_DCS_READ,
 739                 .tx_buf = &cmd,
 740                 .tx_len = 1,
 741                 .rx_buf = data,
 742                 .rx_len = len
 743         };
 744
 745         return mipi_dsi_device_transfer(dsi, &msg);
 746 }
 747 EXPORT_SYMBOL(mipi_dsi_dcs_read);
 748
 749 /**
 750  * mipi_dsi_dcs_nop() - send DCS nop packet
 751  * @dsi: DSI peripheral device
 752  *
 753  * Return: 0 on success or a negative error code on failure.
 754  */
 755 int mipi_dsi_dcs_nop(struct mipi_dsi_device *dsi)
 756 {
 757         ssize_t err;
 758
 759         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_NOP, NULL, 0);
 760         if (err < 0)
 761                 return err;
 762
 763         return 0;
 764 }
 765 EXPORT_SYMBOL(mipi_dsi_dcs_nop);
 766
 767 /**
 768  * mipi_dsi_dcs_soft_reset() - perform a software reset of the display module
 769  * @dsi: DSI peripheral device
 770  *
 771  * Return: 0 on success or a negative error code on failure.
 772  */
 773 int mipi_dsi_dcs_soft_reset(struct mipi_dsi_device *dsi)
 774 {
 775         ssize_t err;
 776
 777         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SOFT_RESET, NULL, 0);
 778         if (err < 0)
 779                 return err;
 780
 781         return 0;
 782 }
 783 EXPORT_SYMBOL(mipi_dsi_dcs_soft_reset);
 784
 785 /**
 786  * mipi_dsi_dcs_get_power_mode() - query the display module's current power
 787  *    mode
 788  * @dsi: DSI peripheral device
 789  * @mode: return location for the current power mode
 790  *
 791  * Return: 0 on success or a negative error code on failure.
 792  */
 793 int mipi_dsi_dcs_get_power_mode(struct mipi_dsi_device *dsi, u8 *mode)
 794 {
 795         ssize_t err;
 796
 797         err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_POWER_MODE, mode,
 798                                 sizeof(*mode));
 799         if (err <= 0) {
 800                 if (err == 0)
 801                         err = -ENODATA;
 802
 803                 return err;
 804         }
 805
 806         return 0;
 807 }
 808 EXPORT_SYMBOL(mipi_dsi_dcs_get_power_mode);
 809
 810 /**
 811  * mipi_dsi_dcs_get_pixel_format() - gets the pixel format for the RGB image
 812  *    data used by the interface
 813  * @dsi: DSI peripheral device
 814  * @format: return location for the pixel format
 815  *
 816  * Return: 0 on success or a negative error code on failure.
 817  */
 818 int mipi_dsi_dcs_get_pixel_format(struct mipi_dsi_device *dsi, u8 *format)
 819 {
 820         ssize_t err;
 821
 822         err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_PIXEL_FORMAT, format,
 823                                 sizeof(*format));
 824         if (err <= 0) {
 825                 if (err == 0)
 826                         err = -ENODATA;
 827
 828                 return err;
 829         }
 830
 831         return 0;
 832 }
 833 EXPORT_SYMBOL(mipi_dsi_dcs_get_pixel_format);
 834
 835 /**
 836  * mipi_dsi_dcs_enter_sleep_mode() - disable all unnecessary blocks inside the
 837  *    display module except interface communication
 838  * @dsi: DSI peripheral device
 839  *
 840  * Return: 0 on success or a negative error code on failure.
 841  */
 842 int mipi_dsi_dcs_enter_sleep_mode(struct mipi_dsi_device *dsi)
 843 {
 844         ssize_t err;
 845
 846         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_ENTER_SLEEP_MODE, NULL, 0);
 847         if (err < 0)
 848                 return err;
 849
 850         return 0;
 851 }
 852 EXPORT_SYMBOL(mipi_dsi_dcs_enter_sleep_mode);
 853
 854 /**
 855  * mipi_dsi_dcs_exit_sleep_mode() - enable all blocks inside the display
 856  *    module
 857  * @dsi: DSI peripheral device
 858  *
 859  * Return: 0 on success or a negative error code on failure.
 860  */
 861 int mipi_dsi_dcs_exit_sleep_mode(struct mipi_dsi_device *dsi)
 862 {
 863         ssize_t err;
 864
 865         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_EXIT_SLEEP_MODE, NULL, 0);
 866         if (err < 0)
 867                 return err;
 868
 869         return 0;
 870 }
 871 EXPORT_SYMBOL(mipi_dsi_dcs_exit_sleep_mode);
 872
 873 /**
 874  * mipi_dsi_dcs_set_display_off() - stop displaying the image data on the
 875  *    display device
 876  * @dsi: DSI peripheral device
 877  *
 878  * Return: 0 on success or a negative error code on failure.
 879  */
 880 int mipi_dsi_dcs_set_display_off(struct mipi_dsi_device *dsi)
 881 {
 882         ssize_t err;
 883
 884         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_OFF, NULL, 0);
 885         if (err < 0)
 886                 return err;
 887
 888         return 0;
 889 }
 890 EXPORT_SYMBOL(mipi_dsi_dcs_set_display_off);
 891
 892 /**
 893  * mipi_dsi_dcs_set_display_on() - start displaying the image data on the
 894  *    display device
 895  * @dsi: DSI peripheral device
 896  *
 897  * Return: 0 on success or a negative error code on failure
 898  */
 899 int mipi_dsi_dcs_set_display_on(struct mipi_dsi_device *dsi)
 900 {
 901         ssize_t err;
 902
 903         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_ON, NULL, 0);
 904         if (err < 0)
 905                 return err;
 906
 907         return 0;
 908 }
 909 EXPORT_SYMBOL(mipi_dsi_dcs_set_display_on);
 910
 911 /**
 912  * mipi_dsi_dcs_set_column_address() - define the column extent of the frame
 913  *    memory accessed by the host processor
 914  * @dsi: DSI peripheral device
 915  * @start: first column of frame memory
 916  * @end: last column of frame memory
 917  *
 918  * Return: 0 on success or a negative error code on failure.
 919  */
 920 int mipi_dsi_dcs_set_column_address(struct mipi_dsi_device *dsi, u16 start,
 921                                     u16 end)
 922 {
 923         u8 payload[4] = { start >> 8, start & 0xff, end >> 8, end & 0xff };
 924         ssize_t err;
 925
 926         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_COLUMN_ADDRESS, payload,
 927                                  sizeof(payload));
 928         if (err < 0)
 929                 return err;
 930
 931         return 0;
 932 }
 933 EXPORT_SYMBOL(mipi_dsi_dcs_set_column_address);
 934
 935 /**
 936  * mipi_dsi_dcs_set_page_address() - define the page extent of the frame
 937  *    memory accessed by the host processor
 938  * @dsi: DSI peripheral device
 939  * @start: first page of frame memory
 940  * @end: last page of frame memory
 941  *
 942  * Return: 0 on success or a negative error code on failure.
 943  */
 944 int mipi_dsi_dcs_set_page_address(struct mipi_dsi_device *dsi, u16 start,
 945                                   u16 end)
 946 {
 947         u8 payload[4] = { start >> 8, start & 0xff, end >> 8, end & 0xff };
 948         ssize_t err;
 949
 950         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_PAGE_ADDRESS, payload,
 951                                  sizeof(payload));
 952         if (err < 0)
 953                 return err;
 954
 955         return 0;
 956 }
 957 EXPORT_SYMBOL(mipi_dsi_dcs_set_page_address);
 958
 959 /**
 960  * mipi_dsi_dcs_set_tear_off() - turn off the display module's Tearing Effect
 961  *    output signal on the TE signal line
 962  * @dsi: DSI peripheral device
 963  *
 964  * Return: 0 on success or a negative error code on failure
 965  */
 966 int mipi_dsi_dcs_set_tear_off(struct mipi_dsi_device *dsi)
 967 {
 968         ssize_t err;
 969
 970         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_OFF, NULL, 0);
 971         if (err < 0)
 972                 return err;
 973
 974         return 0;
 975 }
 976 EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_off);
 977
 978 /**
 979  * mipi_dsi_dcs_set_tear_on() - turn on the display module's Tearing Effect
 980  *    output signal on the TE signal line.
 981  * @dsi: DSI peripheral device
 982  * @mode: the Tearing Effect Output Line mode
 983  *
 984  * Return: 0 on success or a negative error code on failure
 985  */
 986 int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi,
 987                              enum mipi_dsi_dcs_tear_mode mode)
 988 {
 989         u8 value = mode;
 990         ssize_t err;
 991
 992         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_ON, &value,
 993                                  sizeof(value));
 994         if (err < 0)
 995                 return err;
 996
 997         return 0;
 998 }
 999 EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_on);
1000
1001 /**
1002  * mipi_dsi_dcs_set_tear_scanline() - set the scanline to use as trigger for
1003  *    the Tearing Effect output signal of the display module
1004  * @dsi: DSI peripheral device
1005  * @scanline: scanline to use as trigger
1006  *
1007  * Return: 0 on success or a negative error code on failure
1008  */
1009 int mipi_dsi_dcs_set_tear_scanline(struct mipi_dsi_device *dsi, u16 scanline)
1010 {
1011         u8 payload[3] = { MIPI_DCS_SET_TEAR_SCANLINE, scanline >> 8,
1012                           scanline & 0xff };
1013         ssize_t err;
1014
1015         err = mipi_dsi_generic_write(dsi, payload, sizeof(payload));
1016         if (err < 0)
1017                 return err;
1018
1019         return 0;
1020 }
1021 EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_scanline);
1022
1023 /**
1024  * mipi_dsi_dcs_set_pixel_format() - sets the pixel format for the RGB image
1025  *    data used by the interface
1026  * @dsi: DSI peripheral device
1027  * @format: pixel format
1028  *
1029  * Return: 0 on success or a negative error code on failure.
1030  */
1031 int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format)
1032 {
1033         ssize_t err;
1034
1035         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_PIXEL_FORMAT, &format,
1036                                  sizeof(format));
1037         if (err < 0)
1038                 return err;
1039
1040         return 0;
1041 }
1042 EXPORT_SYMBOL(mipi_dsi_dcs_set_pixel_format);
1043
1044 static int mipi_dsi_drv_probe(struct device *dev)
1045 {
1046         struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
1047         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
1048
1049         return drv->probe(dsi);
1050 }
1051
1052 static int mipi_dsi_drv_remove(struct device *dev)
1053 {
1054         struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
1055         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
1056
1057         return drv->remove(dsi);
1058 }
1059
1060 static void mipi_dsi_drv_shutdown(struct device *dev)
1061 {
1062         struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
1063         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
1064
1065         drv->shutdown(dsi);
1066 }
1067
1068 /**
1069  * mipi_dsi_driver_register_full() - register a driver for DSI devices
1070  * @drv: DSI driver structure
1071  * @owner: owner module
1072  *
1073  * Return: 0 on success or a negative error code on failure.
1074  */
1075 int mipi_dsi_driver_register_full(struct mipi_dsi_driver *drv,
1076                                   struct module *owner)
1077 {
1078         drv->driver.bus = &mipi_dsi_bus_type;
1079         drv->driver.owner = owner;
1080
1081         if (drv->probe)
1082                 drv->driver.probe = mipi_dsi_drv_probe;
1083         if (drv->remove)
1084                 drv->driver.remove = mipi_dsi_drv_remove;
1085         if (drv->shutdown)
1086                 drv->driver.shutdown = mipi_dsi_drv_shutdown;
1087
1088         return driver_register(&drv->driver);
1089 }
1090 EXPORT_SYMBOL(mipi_dsi_driver_register_full);
1091
1092 /**
1093  * mipi_dsi_driver_unregister() - unregister a driver for DSI devices
1094  * @drv: DSI driver structure
1095  *
1096  * Return: 0 on success or a negative error code on failure.
1097  */
1098 void mipi_dsi_driver_unregister(struct mipi_dsi_driver *drv)
1099 {
1100         driver_unregister(&drv->driver);
1101 }
1102 EXPORT_SYMBOL(mipi_dsi_driver_unregister);
1103
1104 static int __init mipi_dsi_bus_init(void)
1105 {
1106         return bus_register(&mipi_dsi_bus_type);
1107 }
1108 postcore_initcall(mipi_dsi_bus_init);
1109
1110 MODULE_AUTHOR("Andrzej Hajda <a.hajda@samsung.com>");
1111 MODULE_DESCRIPTION("MIPI DSI Bus");
1112 MODULE_LICENSE("GPL and additional rights");