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 <drm/drm_dsc.h>
  37 #include <drm/drm_print.h>
  38 #include <video/mipi_display.h>
  39
  40 /**
  41  * DOC: dsi helpers
  42  *
  43  * These functions contain some common logic and helpers to deal with MIPI DSI
  44  * peripherals.
  45  *
  46  * Helpers are provided for a number of standard MIPI DSI command as well as a
  47  * subset of the MIPI DCS command set.
  48  */
  49
  50 static int mipi_dsi_device_match(struct device *dev, struct device_driver *drv)
  51 {
  52         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
  53
  54         /* attempt OF style match */
  55         if (of_driver_match_device(dev, drv))
  56                 return 1;
  57
  58         /* compare DSI device and driver names */
  59         if (!strcmp(dsi->name, drv->name))
  60                 return 1;
  61
  62         return 0;
  63 }
  64
  65 static int mipi_dsi_uevent(struct device *dev, struct kobj_uevent_env *env)
  66 {
  67         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
  68         int err;
  69
  70         err = of_device_uevent_modalias(dev, env);
  71         if (err != -ENODEV)
  72                 return err;
  73
  74         add_uevent_var(env, "MODALIAS=%s%s", MIPI_DSI_MODULE_PREFIX,
  75                        dsi->name);
  76
  77         return 0;
  78 }
  79
  80 static const struct dev_pm_ops mipi_dsi_device_pm_ops = {
  81         .runtime_suspend = pm_generic_runtime_suspend,
  82         .runtime_resume = pm_generic_runtime_resume,
  83         .suspend = pm_generic_suspend,
  84         .resume = pm_generic_resume,
  85         .freeze = pm_generic_freeze,
  86         .thaw = pm_generic_thaw,
  87         .poweroff = pm_generic_poweroff,
  88         .restore = pm_generic_restore,
  89 };
  90
  91 static struct bus_type mipi_dsi_bus_type = {
  92         .name = "mipi-dsi",
  93         .match = mipi_dsi_device_match,
  94         .uevent = mipi_dsi_uevent,
  95         .pm = &mipi_dsi_device_pm_ops,
  96 };
  97
  98 /**
  99  * of_find_mipi_dsi_device_by_node() - find the MIPI DSI device matching a
 100  *    device tree node
 101  * @np: device tree node
 102  *
 103  * Return: A pointer to the MIPI DSI device corresponding to @np or NULL if no
 104  *    such device exists (or has not been registered yet).
 105  */
 106 struct mipi_dsi_device *of_find_mipi_dsi_device_by_node(struct device_node *np)
 107 {
 108         struct device *dev;
 109
 110         dev = bus_find_device_by_of_node(&mipi_dsi_bus_type, np);
 111
 112         return dev ? to_mipi_dsi_device(dev) : NULL;
 113 }
 114 EXPORT_SYMBOL(of_find_mipi_dsi_device_by_node);
 115
 116 static void mipi_dsi_dev_release(struct device *dev)
 117 {
 118         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
 119
 120         of_node_put(dev->of_node);
 121         kfree(dsi);
 122 }
 123
 124 static const struct device_type mipi_dsi_device_type = {
 125         .release = mipi_dsi_dev_release,
 126 };
 127
 128 static struct mipi_dsi_device *mipi_dsi_device_alloc(struct mipi_dsi_host *host)
 129 {
 130         struct mipi_dsi_device *dsi;
 131
 132         dsi = kzalloc(sizeof(*dsi), GFP_KERNEL);
 133         if (!dsi)
 134                 return ERR_PTR(-ENOMEM);
 135
 136         dsi->host = host;
 137         dsi->dev.bus = &mipi_dsi_bus_type;
 138         dsi->dev.parent = host->dev;
 139         dsi->dev.type = &mipi_dsi_device_type;
 140
 141         device_initialize(&dsi->dev);
 142
 143         return dsi;
 144 }
 145
 146 static int mipi_dsi_device_add(struct mipi_dsi_device *dsi)
 147 {
 148         struct mipi_dsi_host *host = dsi->host;
 149
 150         dev_set_name(&dsi->dev, "%s.%d", dev_name(host->dev),  dsi->channel);
 151
 152         return device_add(&dsi->dev);
 153 }
 154
 155 #if IS_ENABLED(CONFIG_OF)
 156 static struct mipi_dsi_device *
 157 of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
 158 {
 159         struct mipi_dsi_device_info info = { };
 160         int ret;
 161         u32 reg;
 162
 163         if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) {
 164                 drm_err(host, "modalias failure on %pOF\n", node);
 165                 return ERR_PTR(-EINVAL);
 166         }
 167
 168         ret = of_property_read_u32(node, "reg", &reg);
 169         if (ret) {
 170                 drm_err(host, "device node %pOF has no valid reg property: %d\n",
 171                         node, ret);
 172                 return ERR_PTR(-EINVAL);
 173         }
 174
 175         info.channel = reg;
 176         info.node = of_node_get(node);
 177
 178         return mipi_dsi_device_register_full(host, &info);
 179 }
 180 #else
 181 static struct mipi_dsi_device *
 182 of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
 183 {
 184         return ERR_PTR(-ENODEV);
 185 }
 186 #endif
 187
 188 /**
 189  * mipi_dsi_device_register_full - create a MIPI DSI device
 190  * @host: DSI host to which this device is connected
 191  * @info: pointer to template containing DSI device information
 192  *
 193  * Create a MIPI DSI device by using the device information provided by
 194  * mipi_dsi_device_info template
 195  *
 196  * Returns:
 197  * A pointer to the newly created MIPI DSI device, or, a pointer encoded
 198  * with an error
 199  */
 200 struct mipi_dsi_device *
 201 mipi_dsi_device_register_full(struct mipi_dsi_host *host,
 202                               const struct mipi_dsi_device_info *info)
 203 {
 204         struct mipi_dsi_device *dsi;
 205         int ret;
 206
 207         if (!info) {
 208                 drm_err(host, "invalid mipi_dsi_device_info pointer\n");
 209                 return ERR_PTR(-EINVAL);
 210         }
 211
 212         if (info->channel > 3) {
 213                 drm_err(host, "invalid virtual channel: %u\n", info->channel);
 214                 return ERR_PTR(-EINVAL);
 215         }
 216
 217         dsi = mipi_dsi_device_alloc(host);
 218         if (IS_ERR(dsi)) {
 219                 drm_err(host, "failed to allocate DSI device %ld\n",
 220                         PTR_ERR(dsi));
 221                 return dsi;
 222         }
 223
 224         dsi->dev.of_node = info->node;
 225         dsi->channel = info->channel;
 226         strlcpy(dsi->name, info->type, sizeof(dsi->name));
 227
 228         ret = mipi_dsi_device_add(dsi);
 229         if (ret) {
 230                 drm_err(host, "failed to add DSI device %d\n", ret);
 231                 kfree(dsi);
 232                 return ERR_PTR(ret);
 233         }
 234
 235         return dsi;
 236 }
 237 EXPORT_SYMBOL(mipi_dsi_device_register_full);
 238
 239 /**
 240  * mipi_dsi_device_unregister - unregister MIPI DSI device
 241  * @dsi: DSI peripheral device
 242  */
 243 void mipi_dsi_device_unregister(struct mipi_dsi_device *dsi)
 244 {
 245         device_unregister(&dsi->dev);
 246 }
 247 EXPORT_SYMBOL(mipi_dsi_device_unregister);
 248
 249 static DEFINE_MUTEX(host_lock);
 250 static LIST_HEAD(host_list);
 251
 252 /**
 253  * of_find_mipi_dsi_host_by_node() - find the MIPI DSI host matching a
 254  *                                   device tree node
 255  * @node: device tree node
 256  *
 257  * Returns:
 258  * A pointer to the MIPI DSI host corresponding to @node or NULL if no
 259  * such device exists (or has not been registered yet).
 260  */
 261 struct mipi_dsi_host *of_find_mipi_dsi_host_by_node(struct device_node *node)
 262 {
 263         struct mipi_dsi_host *host;
 264
 265         mutex_lock(&host_lock);
 266
 267         list_for_each_entry(host, &host_list, list) {
 268                 if (host->dev->of_node == node) {
 269                         mutex_unlock(&host_lock);
 270                         return host;
 271                 }
 272         }
 273
 274         mutex_unlock(&host_lock);
 275
 276         return NULL;
 277 }
 278 EXPORT_SYMBOL(of_find_mipi_dsi_host_by_node);
 279
 280 int mipi_dsi_host_register(struct mipi_dsi_host *host)
 281 {
 282         struct device_node *node;
 283
 284         for_each_available_child_of_node(host->dev->of_node, node) {
 285                 /* skip nodes without reg property */
 286                 if (!of_find_property(node, "reg", NULL))
 287                         continue;
 288                 of_mipi_dsi_device_add(host, node);
 289         }
 290
 291         mutex_lock(&host_lock);
 292         list_add_tail(&host->list, &host_list);
 293         mutex_unlock(&host_lock);
 294
 295         return 0;
 296 }
 297 EXPORT_SYMBOL(mipi_dsi_host_register);
 298
 299 static int mipi_dsi_remove_device_fn(struct device *dev, void *priv)
 300 {
 301         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
 302
 303         mipi_dsi_device_unregister(dsi);
 304
 305         return 0;
 306 }
 307
 308 void mipi_dsi_host_unregister(struct mipi_dsi_host *host)
 309 {
 310         device_for_each_child(host->dev, NULL, mipi_dsi_remove_device_fn);
 311
 312         mutex_lock(&host_lock);
 313         list_del_init(&host->list);
 314         mutex_unlock(&host_lock);
 315 }
 316 EXPORT_SYMBOL(mipi_dsi_host_unregister);
 317
 318 /**
 319  * mipi_dsi_attach - attach a DSI device to its DSI host
 320  * @dsi: DSI peripheral
 321  */
 322 int mipi_dsi_attach(struct mipi_dsi_device *dsi)
 323 {
 324         const struct mipi_dsi_host_ops *ops = dsi->host->ops;
 325
 326         if (!ops || !ops->attach)
 327                 return -ENOSYS;
 328
 329         return ops->attach(dsi->host, dsi);
 330 }
 331 EXPORT_SYMBOL(mipi_dsi_attach);
 332
 333 /**
 334  * mipi_dsi_detach - detach a DSI device from its DSI host
 335  * @dsi: DSI peripheral
 336  */
 337 int mipi_dsi_detach(struct mipi_dsi_device *dsi)
 338 {
 339         const struct mipi_dsi_host_ops *ops = dsi->host->ops;
 340
 341         if (!ops || !ops->detach)
 342                 return -ENOSYS;
 343
 344         return ops->detach(dsi->host, dsi);
 345 }
 346 EXPORT_SYMBOL(mipi_dsi_detach);
 347
 348 static ssize_t mipi_dsi_device_transfer(struct mipi_dsi_device *dsi,
 349                                         struct mipi_dsi_msg *msg)
 350 {
 351         const struct mipi_dsi_host_ops *ops = dsi->host->ops;
 352
 353         if (!ops || !ops->transfer)
 354                 return -ENOSYS;
 355
 356         if (dsi->mode_flags & MIPI_DSI_MODE_LPM)
 357                 msg->flags |= MIPI_DSI_MSG_USE_LPM;
 358
 359         return ops->transfer(dsi->host, msg);
 360 }
 361
 362 /**
 363  * mipi_dsi_packet_format_is_short - check if a packet is of the short format
 364  * @type: MIPI DSI data type of the packet
 365  *
 366  * Return: true if the packet for the given data type is a short packet, false
 367  * otherwise.
 368  */
 369 bool mipi_dsi_packet_format_is_short(u8 type)
 370 {
 371         switch (type) {
 372         case MIPI_DSI_V_SYNC_START:
 373         case MIPI_DSI_V_SYNC_END:
 374         case MIPI_DSI_H_SYNC_START:
 375         case MIPI_DSI_H_SYNC_END:
 376         case MIPI_DSI_COMPRESSION_MODE:
 377         case MIPI_DSI_END_OF_TRANSMISSION:
 378         case MIPI_DSI_COLOR_MODE_OFF:
 379         case MIPI_DSI_COLOR_MODE_ON:
 380         case MIPI_DSI_SHUTDOWN_PERIPHERAL:
 381         case MIPI_DSI_TURN_ON_PERIPHERAL:
 382         case MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM:
 383         case MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM:
 384         case MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM:
 385         case MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM:
 386         case MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM:
 387         case MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM:
 388         case MIPI_DSI_DCS_SHORT_WRITE:
 389         case MIPI_DSI_DCS_SHORT_WRITE_PARAM:
 390         case MIPI_DSI_DCS_READ:
 391         case MIPI_DSI_EXECUTE_QUEUE:
 392         case MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE:
 393                 return true;
 394         }
 395
 396         return false;
 397 }
 398 EXPORT_SYMBOL(mipi_dsi_packet_format_is_short);
 399
 400 /**
 401  * mipi_dsi_packet_format_is_long - check if a packet is of the long format
 402  * @type: MIPI DSI data type of the packet
 403  *
 404  * Return: true if the packet for the given data type is a long packet, false
 405  * otherwise.
 406  */
 407 bool mipi_dsi_packet_format_is_long(u8 type)
 408 {
 409         switch (type) {
 410         case MIPI_DSI_NULL_PACKET:
 411         case MIPI_DSI_BLANKING_PACKET:
 412         case MIPI_DSI_GENERIC_LONG_WRITE:
 413         case MIPI_DSI_DCS_LONG_WRITE:
 414         case MIPI_DSI_PICTURE_PARAMETER_SET:
 415         case MIPI_DSI_COMPRESSED_PIXEL_STREAM:
 416         case MIPI_DSI_LOOSELY_PACKED_PIXEL_STREAM_YCBCR20:
 417         case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR24:
 418         case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR16:
 419         case MIPI_DSI_PACKED_PIXEL_STREAM_30:
 420         case MIPI_DSI_PACKED_PIXEL_STREAM_36:
 421         case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR12:
 422         case MIPI_DSI_PACKED_PIXEL_STREAM_16:
 423         case MIPI_DSI_PACKED_PIXEL_STREAM_18:
 424         case MIPI_DSI_PIXEL_STREAM_3BYTE_18:
 425         case MIPI_DSI_PACKED_PIXEL_STREAM_24:
 426                 return true;
 427         }
 428
 429         return false;
 430 }
 431 EXPORT_SYMBOL(mipi_dsi_packet_format_is_long);
 432
 433 /**
 434  * mipi_dsi_create_packet - create a packet from a message according to the
 435  *     DSI protocol
 436  * @packet: pointer to a DSI packet structure
 437  * @msg: message to translate into a packet
 438  *
 439  * Return: 0 on success or a negative error code on failure.
 440  */
 441 int mipi_dsi_create_packet(struct mipi_dsi_packet *packet,
 442                            const struct mipi_dsi_msg *msg)
 443 {
 444         if (!packet || !msg)
 445                 return -EINVAL;
 446
 447         /* do some minimum sanity checking */
 448         if (!mipi_dsi_packet_format_is_short(msg->type) &&
 449             !mipi_dsi_packet_format_is_long(msg->type))
 450                 return -EINVAL;
 451
 452         if (msg->channel > 3)
 453                 return -EINVAL;
 454
 455         memset(packet, 0, sizeof(*packet));
 456         packet->header[0] = ((msg->channel & 0x3) << 6) | (msg->type & 0x3f);
 457
 458         /* TODO: compute ECC if hardware support is not available */
 459
 460         /*
 461          * Long write packets contain the word count in header bytes 1 and 2.
 462          * The payload follows the header and is word count bytes long.
 463          *
 464          * Short write packets encode up to two parameters in header bytes 1
 465          * and 2.
 466          */
 467         if (mipi_dsi_packet_format_is_long(msg->type)) {
 468                 packet->header[1] = (msg->tx_len >> 0) & 0xff;
 469                 packet->header[2] = (msg->tx_len >> 8) & 0xff;
 470
 471                 packet->payload_length = msg->tx_len;
 472                 packet->payload = msg->tx_buf;
 473         } else {
 474                 const u8 *tx = msg->tx_buf;
 475
 476                 packet->header[1] = (msg->tx_len > 0) ? tx[0] : 0;
 477                 packet->header[2] = (msg->tx_len > 1) ? tx[1] : 0;
 478         }
 479
 480         packet->size = sizeof(packet->header) + packet->payload_length;
 481
 482         return 0;
 483 }
 484 EXPORT_SYMBOL(mipi_dsi_create_packet);
 485
 486 /**
 487  * mipi_dsi_shutdown_peripheral() - sends a Shutdown Peripheral command
 488  * @dsi: DSI peripheral device
 489  *
 490  * Return: 0 on success or a negative error code on failure.
 491  */
 492 int mipi_dsi_shutdown_peripheral(struct mipi_dsi_device *dsi)
 493 {
 494         struct mipi_dsi_msg msg = {
 495                 .channel = dsi->channel,
 496                 .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
 497                 .tx_buf = (u8 [2]) { 0, 0 },
 498                 .tx_len = 2,
 499         };
 500         int ret = mipi_dsi_device_transfer(dsi, &msg);
 501
 502         return (ret < 0) ? ret : 0;
 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         int ret = mipi_dsi_device_transfer(dsi, &msg);
 521
 522         return (ret < 0) ? ret : 0;
 523 }
 524 EXPORT_SYMBOL(mipi_dsi_turn_on_peripheral);
 525
 526 /*
 527  * mipi_dsi_set_maximum_return_packet_size() - specify the maximum size of the
 528  *    the payload in a long packet transmitted from the peripheral back to the
 529  *    host processor
 530  * @dsi: DSI peripheral device
 531  * @value: the maximum size of the payload
 532  *
 533  * Return: 0 on success or a negative error code on failure.
 534  */
 535 int mipi_dsi_set_maximum_return_packet_size(struct mipi_dsi_device *dsi,
 536                                             u16 value)
 537 {
 538         u8 tx[2] = { value & 0xff, value >> 8 };
 539         struct mipi_dsi_msg msg = {
 540                 .channel = dsi->channel,
 541                 .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
 542                 .tx_len = sizeof(tx),
 543                 .tx_buf = tx,
 544         };
 545         int ret = mipi_dsi_device_transfer(dsi, &msg);
 546
 547         return (ret < 0) ? ret : 0;
 548 }
 549 EXPORT_SYMBOL(mipi_dsi_set_maximum_return_packet_size);
 550
 551 /**
 552  * mipi_dsi_compression_mode() - enable/disable DSC on the peripheral
 553  * @dsi: DSI peripheral device
 554  * @enable: Whether to enable or disable the DSC
 555  *
 556  * Enable or disable Display Stream Compression on the peripheral using the
 557  * default Picture Parameter Set and VESA DSC 1.1 algorithm.
 558  *
 559  * Return: 0 on success or a negative error code on failure.
 560  */
 561 ssize_t mipi_dsi_compression_mode(struct mipi_dsi_device *dsi, bool enable)
 562 {
 563         /* Note: Needs updating for non-default PPS or algorithm */
 564         u8 tx[2] = { enable << 0, 0 };
 565         struct mipi_dsi_msg msg = {
 566                 .channel = dsi->channel,
 567                 .type = MIPI_DSI_COMPRESSION_MODE,
 568                 .tx_len = sizeof(tx),
 569                 .tx_buf = tx,
 570         };
 571         int ret = mipi_dsi_device_transfer(dsi, &msg);
 572
 573         return (ret < 0) ? ret : 0;
 574 }
 575 EXPORT_SYMBOL(mipi_dsi_compression_mode);
 576
 577 /**
 578  * mipi_dsi_picture_parameter_set() - transmit the DSC PPS to the peripheral
 579  * @dsi: DSI peripheral device
 580  * @pps: VESA DSC 1.1 Picture Parameter Set
 581  *
 582  * Transmit the VESA DSC 1.1 Picture Parameter Set to the peripheral.
 583  *
 584  * Return: 0 on success or a negative error code on failure.
 585  */
 586 ssize_t mipi_dsi_picture_parameter_set(struct mipi_dsi_device *dsi,
 587                                        const struct drm_dsc_picture_parameter_set *pps)
 588 {
 589         struct mipi_dsi_msg msg = {
 590                 .channel = dsi->channel,
 591                 .type = MIPI_DSI_PICTURE_PARAMETER_SET,
 592                 .tx_len = sizeof(*pps),
 593                 .tx_buf = pps,
 594         };
 595         int ret = mipi_dsi_device_transfer(dsi, &msg);
 596
 597         return (ret < 0) ? ret : 0;
 598 }
 599 EXPORT_SYMBOL(mipi_dsi_picture_parameter_set);
 600
 601 /**
 602  * mipi_dsi_generic_write() - transmit data using a generic write packet
 603  * @dsi: DSI peripheral device
 604  * @payload: buffer containing the payload
 605  * @size: size of payload buffer
 606  *
 607  * This function will automatically choose the right data type depending on
 608  * the payload length.
 609  *
 610  * Return: The number of bytes transmitted on success or a negative error code
 611  * on failure.
 612  */
 613 ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload,
 614                                size_t size)
 615 {
 616         struct mipi_dsi_msg msg = {
 617                 .channel = dsi->channel,
 618                 .tx_buf = payload,
 619                 .tx_len = size
 620         };
 621
 622         switch (size) {
 623         case 0:
 624                 msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
 625                 break;
 626
 627         case 1:
 628                 msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
 629                 break;
 630
 631         case 2:
 632                 msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
 633                 break;
 634
 635         default:
 636                 msg.type = MIPI_DSI_GENERIC_LONG_WRITE;
 637                 break;
 638         }
 639
 640         return mipi_dsi_device_transfer(dsi, &msg);
 641 }
 642 EXPORT_SYMBOL(mipi_dsi_generic_write);
 643
 644 /**
 645  * mipi_dsi_generic_read() - receive data using a generic read packet
 646  * @dsi: DSI peripheral device
 647  * @params: buffer containing the request parameters
 648  * @num_params: number of request parameters
 649  * @data: buffer in which to return the received data
 650  * @size: size of receive buffer
 651  *
 652  * This function will automatically choose the right data type depending on
 653  * the number of parameters passed in.
 654  *
 655  * Return: The number of bytes successfully read or a negative error code on
 656  * failure.
 657  */
 658 ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params,
 659                               size_t num_params, void *data, size_t size)
 660 {
 661         struct mipi_dsi_msg msg = {
 662                 .channel = dsi->channel,
 663                 .tx_len = num_params,
 664                 .tx_buf = params,
 665                 .rx_len = size,
 666                 .rx_buf = data
 667         };
 668
 669         switch (num_params) {
 670         case 0:
 671                 msg.type = MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM;
 672                 break;
 673
 674         case 1:
 675                 msg.type = MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM;
 676                 break;
 677
 678         case 2:
 679                 msg.type = MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM;
 680                 break;
 681
 682         default:
 683                 return -EINVAL;
 684         }
 685
 686         return mipi_dsi_device_transfer(dsi, &msg);
 687 }
 688 EXPORT_SYMBOL(mipi_dsi_generic_read);
 689
 690 /**
 691  * mipi_dsi_dcs_write_buffer() - transmit a DCS command with payload
 692  * @dsi: DSI peripheral device
 693  * @data: buffer containing data to be transmitted
 694  * @len: size of transmission buffer
 695  *
 696  * This function will automatically choose the right data type depending on
 697  * the command payload length.
 698  *
 699  * Return: The number of bytes successfully transmitted or a negative error
 700  * code on failure.
 701  */
 702 ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi,
 703                                   const void *data, size_t len)
 704 {
 705         struct mipi_dsi_msg msg = {
 706                 .channel = dsi->channel,
 707                 .tx_buf = data,
 708                 .tx_len = len
 709         };
 710
 711         switch (len) {
 712         case 0:
 713                 return -EINVAL;
 714
 715         case 1:
 716                 msg.type = MIPI_DSI_DCS_SHORT_WRITE;
 717                 break;
 718
 719         case 2:
 720                 msg.type = MIPI_DSI_DCS_SHORT_WRITE_PARAM;
 721                 break;
 722
 723         default:
 724                 msg.type = MIPI_DSI_DCS_LONG_WRITE;
 725                 break;
 726         }
 727
 728         return mipi_dsi_device_transfer(dsi, &msg);
 729 }
 730 EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer);
 731
 732 /**
 733  * mipi_dsi_dcs_write() - send DCS write command
 734  * @dsi: DSI peripheral device
 735  * @cmd: DCS command
 736  * @data: buffer containing the command payload
 737  * @len: command payload length
 738  *
 739  * This function will automatically choose the right data type depending on
 740  * the command payload length.
 741  *
 742  * Return: The number of bytes successfully transmitted or a negative error
 743  * code on failure.
 744  */
 745 ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd,
 746                            const void *data, size_t len)
 747 {
 748         ssize_t err;
 749         size_t size;
 750         u8 stack_tx[8];
 751         u8 *tx;
 752
 753         size = 1 + len;
 754         if (len > ARRAY_SIZE(stack_tx) - 1) {
 755                 tx = kmalloc(size, GFP_KERNEL);
 756                 if (!tx)
 757                         return -ENOMEM;
 758         } else {
 759                 tx = stack_tx;
 760         }
 761
 762         /* concatenate the DCS command byte and the payload */
 763         tx[0] = cmd;
 764         if (data)
 765                 memcpy(&tx[1], data, len);
 766
 767         err = mipi_dsi_dcs_write_buffer(dsi, tx, size);
 768
 769         if (tx != stack_tx)
 770                 kfree(tx);
 771
 772         return err;
 773 }
 774 EXPORT_SYMBOL(mipi_dsi_dcs_write);
 775
 776 /**
 777  * mipi_dsi_dcs_read() - send DCS read request command
 778  * @dsi: DSI peripheral device
 779  * @cmd: DCS command
 780  * @data: buffer in which to receive data
 781  * @len: size of receive buffer
 782  *
 783  * Return: The number of bytes read or a negative error code on failure.
 784  */
 785 ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, u8 cmd, void *data,
 786                           size_t len)
 787 {
 788         struct mipi_dsi_msg msg = {
 789                 .channel = dsi->channel,
 790                 .type = MIPI_DSI_DCS_READ,
 791                 .tx_buf = &cmd,
 792                 .tx_len = 1,
 793                 .rx_buf = data,
 794                 .rx_len = len
 795         };
 796
 797         return mipi_dsi_device_transfer(dsi, &msg);
 798 }
 799 EXPORT_SYMBOL(mipi_dsi_dcs_read);
 800
 801 /**
 802  * mipi_dsi_dcs_nop() - send DCS nop packet
 803  * @dsi: DSI peripheral device
 804  *
 805  * Return: 0 on success or a negative error code on failure.
 806  */
 807 int mipi_dsi_dcs_nop(struct mipi_dsi_device *dsi)
 808 {
 809         ssize_t err;
 810
 811         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_NOP, NULL, 0);
 812         if (err < 0)
 813                 return err;
 814
 815         return 0;
 816 }
 817 EXPORT_SYMBOL(mipi_dsi_dcs_nop);
 818
 819 /**
 820  * mipi_dsi_dcs_soft_reset() - perform a software reset of the display module
 821  * @dsi: DSI peripheral device
 822  *
 823  * Return: 0 on success or a negative error code on failure.
 824  */
 825 int mipi_dsi_dcs_soft_reset(struct mipi_dsi_device *dsi)
 826 {
 827         ssize_t err;
 828
 829         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SOFT_RESET, NULL, 0);
 830         if (err < 0)
 831                 return err;
 832
 833         return 0;
 834 }
 835 EXPORT_SYMBOL(mipi_dsi_dcs_soft_reset);
 836
 837 /**
 838  * mipi_dsi_dcs_get_power_mode() - query the display module's current power
 839  *    mode
 840  * @dsi: DSI peripheral device
 841  * @mode: return location for the current power mode
 842  *
 843  * Return: 0 on success or a negative error code on failure.
 844  */
 845 int mipi_dsi_dcs_get_power_mode(struct mipi_dsi_device *dsi, u8 *mode)
 846 {
 847         ssize_t err;
 848
 849         err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_POWER_MODE, mode,
 850                                 sizeof(*mode));
 851         if (err <= 0) {
 852                 if (err == 0)
 853                         err = -ENODATA;
 854
 855                 return err;
 856         }
 857
 858         return 0;
 859 }
 860 EXPORT_SYMBOL(mipi_dsi_dcs_get_power_mode);
 861
 862 /**
 863  * mipi_dsi_dcs_get_pixel_format() - gets the pixel format for the RGB image
 864  *    data used by the interface
 865  * @dsi: DSI peripheral device
 866  * @format: return location for the pixel format
 867  *
 868  * Return: 0 on success or a negative error code on failure.
 869  */
 870 int mipi_dsi_dcs_get_pixel_format(struct mipi_dsi_device *dsi, u8 *format)
 871 {
 872         ssize_t err;
 873
 874         err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_PIXEL_FORMAT, format,
 875                                 sizeof(*format));
 876         if (err <= 0) {
 877                 if (err == 0)
 878                         err = -ENODATA;
 879
 880                 return err;
 881         }
 882
 883         return 0;
 884 }
 885 EXPORT_SYMBOL(mipi_dsi_dcs_get_pixel_format);
 886
 887 /**
 888  * mipi_dsi_dcs_enter_sleep_mode() - disable all unnecessary blocks inside the
 889  *    display module except interface communication
 890  * @dsi: DSI peripheral device
 891  *
 892  * Return: 0 on success or a negative error code on failure.
 893  */
 894 int mipi_dsi_dcs_enter_sleep_mode(struct mipi_dsi_device *dsi)
 895 {
 896         ssize_t err;
 897
 898         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_ENTER_SLEEP_MODE, NULL, 0);
 899         if (err < 0)
 900                 return err;
 901
 902         return 0;
 903 }
 904 EXPORT_SYMBOL(mipi_dsi_dcs_enter_sleep_mode);
 905
 906 /**
 907  * mipi_dsi_dcs_exit_sleep_mode() - enable all blocks inside the display
 908  *    module
 909  * @dsi: DSI peripheral device
 910  *
 911  * Return: 0 on success or a negative error code on failure.
 912  */
 913 int mipi_dsi_dcs_exit_sleep_mode(struct mipi_dsi_device *dsi)
 914 {
 915         ssize_t err;
 916
 917         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_EXIT_SLEEP_MODE, NULL, 0);
 918         if (err < 0)
 919                 return err;
 920
 921         return 0;
 922 }
 923 EXPORT_SYMBOL(mipi_dsi_dcs_exit_sleep_mode);
 924
 925 /**
 926  * mipi_dsi_dcs_set_display_off() - stop displaying the image data on the
 927  *    display device
 928  * @dsi: DSI peripheral device
 929  *
 930  * Return: 0 on success or a negative error code on failure.
 931  */
 932 int mipi_dsi_dcs_set_display_off(struct mipi_dsi_device *dsi)
 933 {
 934         ssize_t err;
 935
 936         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_OFF, NULL, 0);
 937         if (err < 0)
 938                 return err;
 939
 940         return 0;
 941 }
 942 EXPORT_SYMBOL(mipi_dsi_dcs_set_display_off);
 943
 944 /**
 945  * mipi_dsi_dcs_set_display_on() - start displaying the image data on the
 946  *    display device
 947  * @dsi: DSI peripheral device
 948  *
 949  * Return: 0 on success or a negative error code on failure
 950  */
 951 int mipi_dsi_dcs_set_display_on(struct mipi_dsi_device *dsi)
 952 {
 953         ssize_t err;
 954
 955         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_ON, NULL, 0);
 956         if (err < 0)
 957                 return err;
 958
 959         return 0;
 960 }
 961 EXPORT_SYMBOL(mipi_dsi_dcs_set_display_on);
 962
 963 /**
 964  * mipi_dsi_dcs_set_column_address() - define the column extent of the frame
 965  *    memory accessed by the host processor
 966  * @dsi: DSI peripheral device
 967  * @start: first column of frame memory
 968  * @end: last column of frame memory
 969  *
 970  * Return: 0 on success or a negative error code on failure.
 971  */
 972 int mipi_dsi_dcs_set_column_address(struct mipi_dsi_device *dsi, u16 start,
 973                                     u16 end)
 974 {
 975         u8 payload[4] = { start >> 8, start & 0xff, end >> 8, end & 0xff };
 976         ssize_t err;
 977
 978         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_COLUMN_ADDRESS, payload,
 979                                  sizeof(payload));
 980         if (err < 0)
 981                 return err;
 982
 983         return 0;
 984 }
 985 EXPORT_SYMBOL(mipi_dsi_dcs_set_column_address);
 986
 987 /**
 988  * mipi_dsi_dcs_set_page_address() - define the page extent of the frame
 989  *    memory accessed by the host processor
 990  * @dsi: DSI peripheral device
 991  * @start: first page of frame memory
 992  * @end: last page of frame memory
 993  *
 994  * Return: 0 on success or a negative error code on failure.
 995  */
 996 int mipi_dsi_dcs_set_page_address(struct mipi_dsi_device *dsi, u16 start,
 997                                   u16 end)
 998 {
 999         u8 payload[4] = { start >> 8, start & 0xff, end >> 8, end & 0xff };
1000         ssize_t err;
1001
1002         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_PAGE_ADDRESS, payload,
1003                                  sizeof(payload));
1004         if (err < 0)
1005                 return err;
1006
1007         return 0;
1008 }
1009 EXPORT_SYMBOL(mipi_dsi_dcs_set_page_address);
1010
1011 /**
1012  * mipi_dsi_dcs_set_tear_off() - turn off the display module's Tearing Effect
1013  *    output signal on the TE signal line
1014  * @dsi: DSI peripheral device
1015  *
1016  * Return: 0 on success or a negative error code on failure
1017  */
1018 int mipi_dsi_dcs_set_tear_off(struct mipi_dsi_device *dsi)
1019 {
1020         ssize_t err;
1021
1022         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_OFF, NULL, 0);
1023         if (err < 0)
1024                 return err;
1025
1026         return 0;
1027 }
1028 EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_off);
1029
1030 /**
1031  * mipi_dsi_dcs_set_tear_on() - turn on the display module's Tearing Effect
1032  *    output signal on the TE signal line.
1033  * @dsi: DSI peripheral device
1034  * @mode: the Tearing Effect Output Line mode
1035  *
1036  * Return: 0 on success or a negative error code on failure
1037  */
1038 int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi,
1039                              enum mipi_dsi_dcs_tear_mode mode)
1040 {
1041         u8 value = mode;
1042         ssize_t err;
1043
1044         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_ON, &value,
1045                                  sizeof(value));
1046         if (err < 0)
1047                 return err;
1048
1049         return 0;
1050 }
1051 EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_on);
1052
1053 /**
1054  * mipi_dsi_dcs_set_pixel_format() - sets the pixel format for the RGB image
1055  *    data used by the interface
1056  * @dsi: DSI peripheral device
1057  * @format: pixel format
1058  *
1059  * Return: 0 on success or a negative error code on failure.
1060  */
1061 int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format)
1062 {
1063         ssize_t err;
1064
1065         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_PIXEL_FORMAT, &format,
1066                                  sizeof(format));
1067         if (err < 0)
1068                 return err;
1069
1070         return 0;
1071 }
1072 EXPORT_SYMBOL(mipi_dsi_dcs_set_pixel_format);
1073
1074 /**
1075  * mipi_dsi_dcs_set_tear_scanline() - set the scanline to use as trigger for
1076  *    the Tearing Effect output signal of the display module
1077  * @dsi: DSI peripheral device
1078  * @scanline: scanline to use as trigger
1079  *
1080  * Return: 0 on success or a negative error code on failure
1081  */
1082 int mipi_dsi_dcs_set_tear_scanline(struct mipi_dsi_device *dsi, u16 scanline)
1083 {
1084         u8 payload[2] = { scanline >> 8, scanline & 0xff };
1085         ssize_t err;
1086
1087         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_SCANLINE, payload,
1088                                  sizeof(payload));
1089         if (err < 0)
1090                 return err;
1091
1092         return 0;
1093 }
1094 EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_scanline);
1095
1096 /**
1097  * mipi_dsi_dcs_set_display_brightness() - sets the brightness value of the
1098  *    display
1099  * @dsi: DSI peripheral device
1100  * @brightness: brightness value
1101  *
1102  * Return: 0 on success or a negative error code on failure.
1103  */
1104 int mipi_dsi_dcs_set_display_brightness(struct mipi_dsi_device *dsi,
1105                                         u16 brightness)
1106 {
1107         u8 payload[2] = { brightness & 0xff, brightness >> 8 };
1108         ssize_t err;
1109
1110         err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_BRIGHTNESS,
1111                                  payload, sizeof(payload));
1112         if (err < 0)
1113                 return err;
1114
1115         return 0;
1116 }
1117 EXPORT_SYMBOL(mipi_dsi_dcs_set_display_brightness);
1118
1119 /**
1120  * mipi_dsi_dcs_get_display_brightness() - gets the current brightness value
1121  *    of the display
1122  * @dsi: DSI peripheral device
1123  * @brightness: brightness value
1124  *
1125  * Return: 0 on success or a negative error code on failure.
1126  */
1127 int mipi_dsi_dcs_get_display_brightness(struct mipi_dsi_device *dsi,
1128                                         u16 *brightness)
1129 {
1130         ssize_t err;
1131
1132         err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_DISPLAY_BRIGHTNESS,
1133                                 brightness, sizeof(*brightness));
1134         if (err <= 0) {
1135                 if (err == 0)
1136                         err = -ENODATA;
1137
1138                 return err;
1139         }
1140
1141         return 0;
1142 }
1143 EXPORT_SYMBOL(mipi_dsi_dcs_get_display_brightness);
1144
1145 static int mipi_dsi_drv_probe(struct device *dev)
1146 {
1147         struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
1148         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
1149
1150         return drv->probe(dsi);
1151 }
1152
1153 static int mipi_dsi_drv_remove(struct device *dev)
1154 {
1155         struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
1156         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
1157
1158         return drv->remove(dsi);
1159 }
1160
1161 static void mipi_dsi_drv_shutdown(struct device *dev)
1162 {
1163         struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
1164         struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
1165
1166         drv->shutdown(dsi);
1167 }
1168
1169 /**
1170  * mipi_dsi_driver_register_full() - register a driver for DSI devices
1171  * @drv: DSI driver structure
1172  * @owner: owner module
1173  *
1174  * Return: 0 on success or a negative error code on failure.
1175  */
1176 int mipi_dsi_driver_register_full(struct mipi_dsi_driver *drv,
1177                                   struct module *owner)
1178 {
1179         drv->driver.bus = &mipi_dsi_bus_type;
1180         drv->driver.owner = owner;
1181
1182         if (drv->probe)
1183                 drv->driver.probe = mipi_dsi_drv_probe;
1184         if (drv->remove)
1185                 drv->driver.remove = mipi_dsi_drv_remove;
1186         if (drv->shutdown)
1187                 drv->driver.shutdown = mipi_dsi_drv_shutdown;
1188
1189         return driver_register(&drv->driver);
1190 }
1191 EXPORT_SYMBOL(mipi_dsi_driver_register_full);
1192
1193 /**
1194  * mipi_dsi_driver_unregister() - unregister a driver for DSI devices
1195  * @drv: DSI driver structure
1196  *
1197  * Return: 0 on success or a negative error code on failure.
1198  */
1199 void mipi_dsi_driver_unregister(struct mipi_dsi_driver *drv)
1200 {
1201         driver_unregister(&drv->driver);
1202 }
1203 EXPORT_SYMBOL(mipi_dsi_driver_unregister);
1204
1205 static int __init mipi_dsi_bus_init(void)
1206 {
1207         return bus_register(&mipi_dsi_bus_type);
1208 }
1209 postcore_initcall(mipi_dsi_bus_init);
1210
1211 MODULE_AUTHOR("Andrzej Hajda <a.hajda@samsung.com>");
1212 MODULE_DESCRIPTION("MIPI DSI Bus");
1213 MODULE_LICENSE("GPL and additional rights");