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