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v4.6
   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
  48static 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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  63static 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
  74static 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
  80static 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 */
  93struct 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}
 101EXPORT_SYMBOL(of_find_mipi_dsi_device_by_node);
 102
 103static 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
 111static const struct device_type mipi_dsi_device_type = {
 112	.release = mipi_dsi_dev_release,
 113};
 114
 115static 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
 133static 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)
 143static struct mipi_dsi_device *
 144of_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
 169static struct mipi_dsi_device *
 170of_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 */
 188struct mipi_dsi_device *
 189mipi_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}
 226EXPORT_SYMBOL(mipi_dsi_device_register_full);
 227
 228/**
 229 * mipi_dsi_device_unregister - unregister MIPI DSI device
 230 * @dsi: DSI peripheral device
 231 */
 232void mipi_dsi_device_unregister(struct mipi_dsi_device *dsi)
 233{
 234	device_unregister(&dsi->dev);
 235}
 236EXPORT_SYMBOL(mipi_dsi_device_unregister);
 237
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 238static DEFINE_MUTEX(host_lock);
 239static 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 */
 250struct 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}
 267EXPORT_SYMBOL(of_find_mipi_dsi_host_by_node);
 268
 269int 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}
 286EXPORT_SYMBOL(mipi_dsi_host_register);
 287
 288static 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
 297void 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}
 305EXPORT_SYMBOL(mipi_dsi_host_unregister);
 306
 307/**
 308 * mipi_dsi_attach - attach a DSI device to its DSI host
 309 * @dsi: DSI peripheral
 310 */
 311int 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}
 320EXPORT_SYMBOL(mipi_dsi_attach);
 321
 322/**
 323 * mipi_dsi_detach - detach a DSI device from its DSI host
 324 * @dsi: DSI peripheral
 325 */
 326int 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}
 335EXPORT_SYMBOL(mipi_dsi_detach);
 336
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 337static 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 */
 358bool 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}
 385EXPORT_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 */
 394bool 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}
 416EXPORT_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 */
 426int 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}
 469EXPORT_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 */
 477int 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}
 488EXPORT_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 */
 496int 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}
 507EXPORT_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 */
 518int 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}
 531EXPORT_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 */
 545ssize_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}
 574EXPORT_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 */
 590ssize_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}
 620EXPORT_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 */
 634ssize_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}
 662EXPORT_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 */
 677ssize_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}
 706EXPORT_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 */
 717ssize_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}
 731EXPORT_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 */
 739int 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}
 749EXPORT_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 */
 757int 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}
 767EXPORT_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 */
 777int 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}
 792EXPORT_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 */
 802int 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}
 817EXPORT_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 */
 826int 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}
 836EXPORT_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 */
 845int 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}
 855EXPORT_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 */
 864int 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}
 874EXPORT_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 */
 883int 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}
 893EXPORT_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 */
 904int 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}
 917EXPORT_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 */
 928int 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}
 941EXPORT_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 */
 950int 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}
 960EXPORT_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 */
 970int 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}
 983EXPORT_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 */
 993int 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}
1004EXPORT_SYMBOL(mipi_dsi_dcs_set_pixel_format);
1005
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1006static 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
1014static 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
1022static 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 */
1037int 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}
1052EXPORT_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 */
1060void mipi_dsi_driver_unregister(struct mipi_dsi_driver *drv)
1061{
1062	driver_unregister(&drv->driver);
1063}
1064EXPORT_SYMBOL(mipi_dsi_driver_unregister);
1065
1066static int __init mipi_dsi_bus_init(void)
1067{
1068	return bus_register(&mipi_dsi_bus_type);
1069}
1070postcore_initcall(mipi_dsi_bus_init);
1071
1072MODULE_AUTHOR("Andrzej Hajda <a.hajda@samsung.com>");
1073MODULE_DESCRIPTION("MIPI DSI Bus");
1074MODULE_LICENSE("GPL and additional rights");
v6.8
   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 <linux/device.h>
  29#include <linux/module.h>
  30#include <linux/of.h>
  31#include <linux/of_device.h>
  32#include <linux/pm_runtime.h>
  33#include <linux/slab.h>
  34
  35#include <drm/display/drm_dsc.h>
  36#include <drm/drm_mipi_dsi.h>
  37#include <drm/drm_print.h>
  38
  39#include <video/mipi_display.h>
  40
  41/**
  42 * DOC: dsi helpers
  43 *
  44 * These functions contain some common logic and helpers to deal with MIPI DSI
  45 * peripherals.
  46 *
  47 * Helpers are provided for a number of standard MIPI DSI command as well as a
  48 * subset of the MIPI DCS command set.
  49 */
  50
  51static int mipi_dsi_device_match(struct device *dev, struct device_driver *drv)
  52{
  53	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
  54
  55	/* attempt OF style match */
  56	if (of_driver_match_device(dev, drv))
  57		return 1;
  58
  59	/* compare DSI device and driver names */
  60	if (!strcmp(dsi->name, drv->name))
  61		return 1;
  62
  63	return 0;
  64}
  65
  66static int mipi_dsi_uevent(const struct device *dev, struct kobj_uevent_env *env)
  67{
  68	const struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
  69	int err;
  70
  71	err = of_device_uevent_modalias(dev, env);
  72	if (err != -ENODEV)
  73		return err;
  74
  75	add_uevent_var(env, "MODALIAS=%s%s", MIPI_DSI_MODULE_PREFIX,
  76		       dsi->name);
  77
  78	return 0;
  79}
  80
  81static const struct dev_pm_ops mipi_dsi_device_pm_ops = {
  82	.runtime_suspend = pm_generic_runtime_suspend,
  83	.runtime_resume = pm_generic_runtime_resume,
  84	.suspend = pm_generic_suspend,
  85	.resume = pm_generic_resume,
  86	.freeze = pm_generic_freeze,
  87	.thaw = pm_generic_thaw,
  88	.poweroff = pm_generic_poweroff,
  89	.restore = pm_generic_restore,
  90};
  91
  92static struct bus_type mipi_dsi_bus_type = {
  93	.name = "mipi-dsi",
  94	.match = mipi_dsi_device_match,
  95	.uevent = mipi_dsi_uevent,
  96	.pm = &mipi_dsi_device_pm_ops,
  97};
  98
 
 
 
 
 
  99/**
 100 * of_find_mipi_dsi_device_by_node() - find the MIPI DSI device matching a
 101 *    device tree node
 102 * @np: device tree node
 103 *
 104 * Return: A pointer to the MIPI DSI device corresponding to @np or NULL if no
 105 *    such device exists (or has not been registered yet).
 106 */
 107struct mipi_dsi_device *of_find_mipi_dsi_device_by_node(struct device_node *np)
 108{
 109	struct device *dev;
 110
 111	dev = bus_find_device_by_of_node(&mipi_dsi_bus_type, np);
 112
 113	return dev ? to_mipi_dsi_device(dev) : NULL;
 114}
 115EXPORT_SYMBOL(of_find_mipi_dsi_device_by_node);
 116
 117static void mipi_dsi_dev_release(struct device *dev)
 118{
 119	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
 120
 121	of_node_put(dev->of_node);
 122	kfree(dsi);
 123}
 124
 125static const struct device_type mipi_dsi_device_type = {
 126	.release = mipi_dsi_dev_release,
 127};
 128
 129static struct mipi_dsi_device *mipi_dsi_device_alloc(struct mipi_dsi_host *host)
 130{
 131	struct mipi_dsi_device *dsi;
 132
 133	dsi = kzalloc(sizeof(*dsi), GFP_KERNEL);
 134	if (!dsi)
 135		return ERR_PTR(-ENOMEM);
 136
 137	dsi->host = host;
 138	dsi->dev.bus = &mipi_dsi_bus_type;
 139	dsi->dev.parent = host->dev;
 140	dsi->dev.type = &mipi_dsi_device_type;
 141
 142	device_initialize(&dsi->dev);
 143
 144	return dsi;
 145}
 146
 147static int mipi_dsi_device_add(struct mipi_dsi_device *dsi)
 148{
 149	struct mipi_dsi_host *host = dsi->host;
 150
 151	dev_set_name(&dsi->dev, "%s.%d", dev_name(host->dev),  dsi->channel);
 152
 153	return device_add(&dsi->dev);
 154}
 155
 156#if IS_ENABLED(CONFIG_OF)
 157static struct mipi_dsi_device *
 158of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
 159{
 
 160	struct mipi_dsi_device_info info = { };
 161	int ret;
 162	u32 reg;
 163
 164	if (of_alias_from_compatible(node, info.type, sizeof(info.type)) < 0) {
 165		drm_err(host, "modalias failure on %pOF\n", node);
 166		return ERR_PTR(-EINVAL);
 167	}
 168
 169	ret = of_property_read_u32(node, "reg", &reg);
 170	if (ret) {
 171		drm_err(host, "device node %pOF has no valid reg property: %d\n",
 172			node, ret);
 173		return ERR_PTR(-EINVAL);
 174	}
 175
 176	info.channel = reg;
 177	info.node = of_node_get(node);
 178
 179	return mipi_dsi_device_register_full(host, &info);
 180}
 181#else
 182static struct mipi_dsi_device *
 183of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
 184{
 185	return ERR_PTR(-ENODEV);
 186}
 187#endif
 188
 189/**
 190 * mipi_dsi_device_register_full - create a MIPI DSI device
 191 * @host: DSI host to which this device is connected
 192 * @info: pointer to template containing DSI device information
 193 *
 194 * Create a MIPI DSI device by using the device information provided by
 195 * mipi_dsi_device_info template
 196 *
 197 * Returns:
 198 * A pointer to the newly created MIPI DSI device, or, a pointer encoded
 199 * with an error
 200 */
 201struct mipi_dsi_device *
 202mipi_dsi_device_register_full(struct mipi_dsi_host *host,
 203			      const struct mipi_dsi_device_info *info)
 204{
 205	struct mipi_dsi_device *dsi;
 
 206	int ret;
 207
 208	if (!info) {
 209		drm_err(host, "invalid mipi_dsi_device_info pointer\n");
 210		return ERR_PTR(-EINVAL);
 211	}
 212
 213	if (info->channel > 3) {
 214		drm_err(host, "invalid virtual channel: %u\n", info->channel);
 215		return ERR_PTR(-EINVAL);
 216	}
 217
 218	dsi = mipi_dsi_device_alloc(host);
 219	if (IS_ERR(dsi)) {
 220		drm_err(host, "failed to allocate DSI device %ld\n",
 221			PTR_ERR(dsi));
 222		return dsi;
 223	}
 224
 225	device_set_node(&dsi->dev, of_fwnode_handle(info->node));
 226	dsi->channel = info->channel;
 227	strscpy(dsi->name, info->type, sizeof(dsi->name));
 228
 229	ret = mipi_dsi_device_add(dsi);
 230	if (ret) {
 231		drm_err(host, "failed to add DSI device %d\n", ret);
 232		kfree(dsi);
 233		return ERR_PTR(ret);
 234	}
 235
 236	return dsi;
 237}
 238EXPORT_SYMBOL(mipi_dsi_device_register_full);
 239
 240/**
 241 * mipi_dsi_device_unregister - unregister MIPI DSI device
 242 * @dsi: DSI peripheral device
 243 */
 244void mipi_dsi_device_unregister(struct mipi_dsi_device *dsi)
 245{
 246	device_unregister(&dsi->dev);
 247}
 248EXPORT_SYMBOL(mipi_dsi_device_unregister);
 249
 250static void devm_mipi_dsi_device_unregister(void *arg)
 251{
 252	struct mipi_dsi_device *dsi = arg;
 253
 254	mipi_dsi_device_unregister(dsi);
 255}
 256
 257/**
 258 * devm_mipi_dsi_device_register_full - create a managed MIPI DSI device
 259 * @dev: device to tie the MIPI-DSI device lifetime to
 260 * @host: DSI host to which this device is connected
 261 * @info: pointer to template containing DSI device information
 262 *
 263 * Create a MIPI DSI device by using the device information provided by
 264 * mipi_dsi_device_info template
 265 *
 266 * This is the managed version of mipi_dsi_device_register_full() which
 267 * automatically calls mipi_dsi_device_unregister() when @dev is
 268 * unbound.
 269 *
 270 * Returns:
 271 * A pointer to the newly created MIPI DSI device, or, a pointer encoded
 272 * with an error
 273 */
 274struct mipi_dsi_device *
 275devm_mipi_dsi_device_register_full(struct device *dev,
 276				   struct mipi_dsi_host *host,
 277				   const struct mipi_dsi_device_info *info)
 278{
 279	struct mipi_dsi_device *dsi;
 280	int ret;
 281
 282	dsi = mipi_dsi_device_register_full(host, info);
 283	if (IS_ERR(dsi))
 284		return dsi;
 285
 286	ret = devm_add_action_or_reset(dev,
 287				       devm_mipi_dsi_device_unregister,
 288				       dsi);
 289	if (ret)
 290		return ERR_PTR(ret);
 291
 292	return dsi;
 293}
 294EXPORT_SYMBOL_GPL(devm_mipi_dsi_device_register_full);
 295
 296static DEFINE_MUTEX(host_lock);
 297static LIST_HEAD(host_list);
 298
 299/**
 300 * of_find_mipi_dsi_host_by_node() - find the MIPI DSI host matching a
 301 *				     device tree node
 302 * @node: device tree node
 303 *
 304 * Returns:
 305 * A pointer to the MIPI DSI host corresponding to @node or NULL if no
 306 * such device exists (or has not been registered yet).
 307 */
 308struct mipi_dsi_host *of_find_mipi_dsi_host_by_node(struct device_node *node)
 309{
 310	struct mipi_dsi_host *host;
 311
 312	mutex_lock(&host_lock);
 313
 314	list_for_each_entry(host, &host_list, list) {
 315		if (host->dev->of_node == node) {
 316			mutex_unlock(&host_lock);
 317			return host;
 318		}
 319	}
 320
 321	mutex_unlock(&host_lock);
 322
 323	return NULL;
 324}
 325EXPORT_SYMBOL(of_find_mipi_dsi_host_by_node);
 326
 327int mipi_dsi_host_register(struct mipi_dsi_host *host)
 328{
 329	struct device_node *node;
 330
 331	for_each_available_child_of_node(host->dev->of_node, node) {
 332		/* skip nodes without reg property */
 333		if (!of_property_present(node, "reg"))
 334			continue;
 335		of_mipi_dsi_device_add(host, node);
 336	}
 337
 338	mutex_lock(&host_lock);
 339	list_add_tail(&host->list, &host_list);
 340	mutex_unlock(&host_lock);
 341
 342	return 0;
 343}
 344EXPORT_SYMBOL(mipi_dsi_host_register);
 345
 346static int mipi_dsi_remove_device_fn(struct device *dev, void *priv)
 347{
 348	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
 349
 350	if (dsi->attached)
 351		mipi_dsi_detach(dsi);
 352	mipi_dsi_device_unregister(dsi);
 353
 354	return 0;
 355}
 356
 357void mipi_dsi_host_unregister(struct mipi_dsi_host *host)
 358{
 359	device_for_each_child(host->dev, NULL, mipi_dsi_remove_device_fn);
 360
 361	mutex_lock(&host_lock);
 362	list_del_init(&host->list);
 363	mutex_unlock(&host_lock);
 364}
 365EXPORT_SYMBOL(mipi_dsi_host_unregister);
 366
 367/**
 368 * mipi_dsi_attach - attach a DSI device to its DSI host
 369 * @dsi: DSI peripheral
 370 */
 371int mipi_dsi_attach(struct mipi_dsi_device *dsi)
 372{
 373	const struct mipi_dsi_host_ops *ops = dsi->host->ops;
 374	int ret;
 375
 376	if (!ops || !ops->attach)
 377		return -ENOSYS;
 378
 379	ret = ops->attach(dsi->host, dsi);
 380	if (ret)
 381		return ret;
 382
 383	dsi->attached = true;
 384
 385	return 0;
 386}
 387EXPORT_SYMBOL(mipi_dsi_attach);
 388
 389/**
 390 * mipi_dsi_detach - detach a DSI device from its DSI host
 391 * @dsi: DSI peripheral
 392 */
 393int mipi_dsi_detach(struct mipi_dsi_device *dsi)
 394{
 395	const struct mipi_dsi_host_ops *ops = dsi->host->ops;
 396
 397	if (WARN_ON(!dsi->attached))
 398		return -EINVAL;
 399
 400	if (!ops || !ops->detach)
 401		return -ENOSYS;
 402
 403	dsi->attached = false;
 404
 405	return ops->detach(dsi->host, dsi);
 406}
 407EXPORT_SYMBOL(mipi_dsi_detach);
 408
 409static void devm_mipi_dsi_detach(void *arg)
 410{
 411	struct mipi_dsi_device *dsi = arg;
 412
 413	mipi_dsi_detach(dsi);
 414}
 415
 416/**
 417 * devm_mipi_dsi_attach - Attach a MIPI-DSI device to its DSI Host
 418 * @dev: device to tie the MIPI-DSI device attachment lifetime to
 419 * @dsi: DSI peripheral
 420 *
 421 * This is the managed version of mipi_dsi_attach() which automatically
 422 * calls mipi_dsi_detach() when @dev is unbound.
 423 *
 424 * Returns:
 425 * 0 on success, a negative error code on failure.
 426 */
 427int devm_mipi_dsi_attach(struct device *dev,
 428			 struct mipi_dsi_device *dsi)
 429{
 430	int ret;
 431
 432	ret = mipi_dsi_attach(dsi);
 433	if (ret)
 434		return ret;
 435
 436	ret = devm_add_action_or_reset(dev, devm_mipi_dsi_detach, dsi);
 437	if (ret)
 438		return ret;
 439
 440	return 0;
 441}
 442EXPORT_SYMBOL_GPL(devm_mipi_dsi_attach);
 443
 444static ssize_t mipi_dsi_device_transfer(struct mipi_dsi_device *dsi,
 445					struct mipi_dsi_msg *msg)
 446{
 447	const struct mipi_dsi_host_ops *ops = dsi->host->ops;
 448
 449	if (!ops || !ops->transfer)
 450		return -ENOSYS;
 451
 452	if (dsi->mode_flags & MIPI_DSI_MODE_LPM)
 453		msg->flags |= MIPI_DSI_MSG_USE_LPM;
 454
 455	return ops->transfer(dsi->host, msg);
 456}
 457
 458/**
 459 * mipi_dsi_packet_format_is_short - check if a packet is of the short format
 460 * @type: MIPI DSI data type of the packet
 461 *
 462 * Return: true if the packet for the given data type is a short packet, false
 463 * otherwise.
 464 */
 465bool mipi_dsi_packet_format_is_short(u8 type)
 466{
 467	switch (type) {
 468	case MIPI_DSI_V_SYNC_START:
 469	case MIPI_DSI_V_SYNC_END:
 470	case MIPI_DSI_H_SYNC_START:
 471	case MIPI_DSI_H_SYNC_END:
 472	case MIPI_DSI_COMPRESSION_MODE:
 473	case MIPI_DSI_END_OF_TRANSMISSION:
 474	case MIPI_DSI_COLOR_MODE_OFF:
 475	case MIPI_DSI_COLOR_MODE_ON:
 476	case MIPI_DSI_SHUTDOWN_PERIPHERAL:
 477	case MIPI_DSI_TURN_ON_PERIPHERAL:
 478	case MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM:
 479	case MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM:
 480	case MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM:
 481	case MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM:
 482	case MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM:
 483	case MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM:
 484	case MIPI_DSI_DCS_SHORT_WRITE:
 485	case MIPI_DSI_DCS_SHORT_WRITE_PARAM:
 486	case MIPI_DSI_DCS_READ:
 487	case MIPI_DSI_EXECUTE_QUEUE:
 488	case MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE:
 489		return true;
 490	}
 491
 492	return false;
 493}
 494EXPORT_SYMBOL(mipi_dsi_packet_format_is_short);
 495
 496/**
 497 * mipi_dsi_packet_format_is_long - check if a packet is of the long format
 498 * @type: MIPI DSI data type of the packet
 499 *
 500 * Return: true if the packet for the given data type is a long packet, false
 501 * otherwise.
 502 */
 503bool mipi_dsi_packet_format_is_long(u8 type)
 504{
 505	switch (type) {
 506	case MIPI_DSI_NULL_PACKET:
 507	case MIPI_DSI_BLANKING_PACKET:
 508	case MIPI_DSI_GENERIC_LONG_WRITE:
 509	case MIPI_DSI_DCS_LONG_WRITE:
 510	case MIPI_DSI_PICTURE_PARAMETER_SET:
 511	case MIPI_DSI_COMPRESSED_PIXEL_STREAM:
 512	case MIPI_DSI_LOOSELY_PACKED_PIXEL_STREAM_YCBCR20:
 513	case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR24:
 514	case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR16:
 515	case MIPI_DSI_PACKED_PIXEL_STREAM_30:
 516	case MIPI_DSI_PACKED_PIXEL_STREAM_36:
 517	case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR12:
 518	case MIPI_DSI_PACKED_PIXEL_STREAM_16:
 519	case MIPI_DSI_PACKED_PIXEL_STREAM_18:
 520	case MIPI_DSI_PIXEL_STREAM_3BYTE_18:
 521	case MIPI_DSI_PACKED_PIXEL_STREAM_24:
 522		return true;
 523	}
 524
 525	return false;
 526}
 527EXPORT_SYMBOL(mipi_dsi_packet_format_is_long);
 528
 529/**
 530 * mipi_dsi_create_packet - create a packet from a message according to the
 531 *     DSI protocol
 532 * @packet: pointer to a DSI packet structure
 533 * @msg: message to translate into a packet
 534 *
 535 * Return: 0 on success or a negative error code on failure.
 536 */
 537int mipi_dsi_create_packet(struct mipi_dsi_packet *packet,
 538			   const struct mipi_dsi_msg *msg)
 539{
 540	if (!packet || !msg)
 541		return -EINVAL;
 542
 543	/* do some minimum sanity checking */
 544	if (!mipi_dsi_packet_format_is_short(msg->type) &&
 545	    !mipi_dsi_packet_format_is_long(msg->type))
 546		return -EINVAL;
 547
 548	if (msg->channel > 3)
 549		return -EINVAL;
 550
 551	memset(packet, 0, sizeof(*packet));
 552	packet->header[0] = ((msg->channel & 0x3) << 6) | (msg->type & 0x3f);
 553
 554	/* TODO: compute ECC if hardware support is not available */
 555
 556	/*
 557	 * Long write packets contain the word count in header bytes 1 and 2.
 558	 * The payload follows the header and is word count bytes long.
 559	 *
 560	 * Short write packets encode up to two parameters in header bytes 1
 561	 * and 2.
 562	 */
 563	if (mipi_dsi_packet_format_is_long(msg->type)) {
 564		packet->header[1] = (msg->tx_len >> 0) & 0xff;
 565		packet->header[2] = (msg->tx_len >> 8) & 0xff;
 566
 567		packet->payload_length = msg->tx_len;
 568		packet->payload = msg->tx_buf;
 569	} else {
 570		const u8 *tx = msg->tx_buf;
 571
 572		packet->header[1] = (msg->tx_len > 0) ? tx[0] : 0;
 573		packet->header[2] = (msg->tx_len > 1) ? tx[1] : 0;
 574	}
 575
 576	packet->size = sizeof(packet->header) + packet->payload_length;
 577
 578	return 0;
 579}
 580EXPORT_SYMBOL(mipi_dsi_create_packet);
 581
 582/**
 583 * mipi_dsi_shutdown_peripheral() - sends a Shutdown Peripheral command
 584 * @dsi: DSI peripheral device
 585 *
 586 * Return: 0 on success or a negative error code on failure.
 587 */
 588int mipi_dsi_shutdown_peripheral(struct mipi_dsi_device *dsi)
 589{
 590	struct mipi_dsi_msg msg = {
 591		.channel = dsi->channel,
 592		.type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
 593		.tx_buf = (u8 [2]) { 0, 0 },
 594		.tx_len = 2,
 595	};
 596	int ret = mipi_dsi_device_transfer(dsi, &msg);
 597
 598	return (ret < 0) ? ret : 0;
 599}
 600EXPORT_SYMBOL(mipi_dsi_shutdown_peripheral);
 601
 602/**
 603 * mipi_dsi_turn_on_peripheral() - sends a Turn On Peripheral command
 604 * @dsi: DSI peripheral device
 605 *
 606 * Return: 0 on success or a negative error code on failure.
 607 */
 608int mipi_dsi_turn_on_peripheral(struct mipi_dsi_device *dsi)
 609{
 610	struct mipi_dsi_msg msg = {
 611		.channel = dsi->channel,
 612		.type = MIPI_DSI_TURN_ON_PERIPHERAL,
 613		.tx_buf = (u8 [2]) { 0, 0 },
 614		.tx_len = 2,
 615	};
 616	int ret = mipi_dsi_device_transfer(dsi, &msg);
 617
 618	return (ret < 0) ? ret : 0;
 619}
 620EXPORT_SYMBOL(mipi_dsi_turn_on_peripheral);
 621
 622/*
 623 * mipi_dsi_set_maximum_return_packet_size() - specify the maximum size of
 624 *    the payload in a long packet transmitted from the peripheral back to the
 625 *    host processor
 626 * @dsi: DSI peripheral device
 627 * @value: the maximum size of the payload
 628 *
 629 * Return: 0 on success or a negative error code on failure.
 630 */
 631int mipi_dsi_set_maximum_return_packet_size(struct mipi_dsi_device *dsi,
 632					    u16 value)
 633{
 634	u8 tx[2] = { value & 0xff, value >> 8 };
 635	struct mipi_dsi_msg msg = {
 636		.channel = dsi->channel,
 637		.type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
 638		.tx_len = sizeof(tx),
 639		.tx_buf = tx,
 640	};
 641	int ret = mipi_dsi_device_transfer(dsi, &msg);
 642
 643	return (ret < 0) ? ret : 0;
 644}
 645EXPORT_SYMBOL(mipi_dsi_set_maximum_return_packet_size);
 646
 647/**
 648 * mipi_dsi_compression_mode() - enable/disable DSC on the peripheral
 649 * @dsi: DSI peripheral device
 650 * @enable: Whether to enable or disable the DSC
 651 *
 652 * Enable or disable Display Stream Compression on the peripheral using the
 653 * default Picture Parameter Set and VESA DSC 1.1 algorithm.
 654 *
 655 * Return: 0 on success or a negative error code on failure.
 656 */
 657ssize_t mipi_dsi_compression_mode(struct mipi_dsi_device *dsi, bool enable)
 658{
 659	/* Note: Needs updating for non-default PPS or algorithm */
 660	u8 tx[2] = { enable << 0, 0 };
 661	struct mipi_dsi_msg msg = {
 662		.channel = dsi->channel,
 663		.type = MIPI_DSI_COMPRESSION_MODE,
 664		.tx_len = sizeof(tx),
 665		.tx_buf = tx,
 666	};
 667	int ret = mipi_dsi_device_transfer(dsi, &msg);
 668
 669	return (ret < 0) ? ret : 0;
 670}
 671EXPORT_SYMBOL(mipi_dsi_compression_mode);
 672
 673/**
 674 * mipi_dsi_picture_parameter_set() - transmit the DSC PPS to the peripheral
 675 * @dsi: DSI peripheral device
 676 * @pps: VESA DSC 1.1 Picture Parameter Set
 677 *
 678 * Transmit the VESA DSC 1.1 Picture Parameter Set to the peripheral.
 679 *
 680 * Return: 0 on success or a negative error code on failure.
 681 */
 682ssize_t mipi_dsi_picture_parameter_set(struct mipi_dsi_device *dsi,
 683				       const struct drm_dsc_picture_parameter_set *pps)
 684{
 685	struct mipi_dsi_msg msg = {
 686		.channel = dsi->channel,
 687		.type = MIPI_DSI_PICTURE_PARAMETER_SET,
 688		.tx_len = sizeof(*pps),
 689		.tx_buf = pps,
 690	};
 691	int ret = mipi_dsi_device_transfer(dsi, &msg);
 692
 693	return (ret < 0) ? ret : 0;
 694}
 695EXPORT_SYMBOL(mipi_dsi_picture_parameter_set);
 696
 697/**
 698 * mipi_dsi_generic_write() - transmit data using a generic write packet
 699 * @dsi: DSI peripheral device
 700 * @payload: buffer containing the payload
 701 * @size: size of payload buffer
 702 *
 703 * This function will automatically choose the right data type depending on
 704 * the payload length.
 705 *
 706 * Return: The number of bytes transmitted on success or a negative error code
 707 * on failure.
 708 */
 709ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload,
 710			       size_t size)
 711{
 712	struct mipi_dsi_msg msg = {
 713		.channel = dsi->channel,
 714		.tx_buf = payload,
 715		.tx_len = size
 716	};
 717
 718	switch (size) {
 719	case 0:
 720		msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
 721		break;
 722
 723	case 1:
 724		msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
 725		break;
 726
 727	case 2:
 728		msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
 729		break;
 730
 731	default:
 732		msg.type = MIPI_DSI_GENERIC_LONG_WRITE;
 733		break;
 734	}
 735
 736	return mipi_dsi_device_transfer(dsi, &msg);
 737}
 738EXPORT_SYMBOL(mipi_dsi_generic_write);
 739
 740/**
 741 * mipi_dsi_generic_read() - receive data using a generic read packet
 742 * @dsi: DSI peripheral device
 743 * @params: buffer containing the request parameters
 744 * @num_params: number of request parameters
 745 * @data: buffer in which to return the received data
 746 * @size: size of receive buffer
 747 *
 748 * This function will automatically choose the right data type depending on
 749 * the number of parameters passed in.
 750 *
 751 * Return: The number of bytes successfully read or a negative error code on
 752 * failure.
 753 */
 754ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params,
 755			      size_t num_params, void *data, size_t size)
 756{
 757	struct mipi_dsi_msg msg = {
 758		.channel = dsi->channel,
 759		.tx_len = num_params,
 760		.tx_buf = params,
 761		.rx_len = size,
 762		.rx_buf = data
 763	};
 764
 765	switch (num_params) {
 766	case 0:
 767		msg.type = MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM;
 768		break;
 769
 770	case 1:
 771		msg.type = MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM;
 772		break;
 773
 774	case 2:
 775		msg.type = MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM;
 776		break;
 777
 778	default:
 779		return -EINVAL;
 780	}
 781
 782	return mipi_dsi_device_transfer(dsi, &msg);
 783}
 784EXPORT_SYMBOL(mipi_dsi_generic_read);
 785
 786/**
 787 * mipi_dsi_dcs_write_buffer() - transmit a DCS command with payload
 788 * @dsi: DSI peripheral device
 789 * @data: buffer containing data to be transmitted
 790 * @len: size of transmission buffer
 791 *
 792 * This function will automatically choose the right data type depending on
 793 * the command payload length.
 794 *
 795 * Return: The number of bytes successfully transmitted or a negative error
 796 * code on failure.
 797 */
 798ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi,
 799				  const void *data, size_t len)
 800{
 801	struct mipi_dsi_msg msg = {
 802		.channel = dsi->channel,
 803		.tx_buf = data,
 804		.tx_len = len
 805	};
 806
 807	switch (len) {
 808	case 0:
 809		return -EINVAL;
 810
 811	case 1:
 812		msg.type = MIPI_DSI_DCS_SHORT_WRITE;
 813		break;
 814
 815	case 2:
 816		msg.type = MIPI_DSI_DCS_SHORT_WRITE_PARAM;
 817		break;
 818
 819	default:
 820		msg.type = MIPI_DSI_DCS_LONG_WRITE;
 821		break;
 822	}
 823
 824	return mipi_dsi_device_transfer(dsi, &msg);
 825}
 826EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer);
 827
 828/**
 829 * mipi_dsi_dcs_write() - send DCS write command
 830 * @dsi: DSI peripheral device
 831 * @cmd: DCS command
 832 * @data: buffer containing the command payload
 833 * @len: command payload length
 834 *
 835 * This function will automatically choose the right data type depending on
 836 * the command payload length.
 837 *
 838 * Return: The number of bytes successfully transmitted or a negative error
 839 * code on failure.
 840 */
 841ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd,
 842			   const void *data, size_t len)
 843{
 844	ssize_t err;
 845	size_t size;
 846	u8 stack_tx[8];
 847	u8 *tx;
 848
 849	size = 1 + len;
 850	if (len > ARRAY_SIZE(stack_tx) - 1) {
 
 851		tx = kmalloc(size, GFP_KERNEL);
 852		if (!tx)
 853			return -ENOMEM;
 
 
 
 
 854	} else {
 855		tx = stack_tx;
 
 856	}
 857
 858	/* concatenate the DCS command byte and the payload */
 859	tx[0] = cmd;
 860	if (data)
 861		memcpy(&tx[1], data, len);
 862
 863	err = mipi_dsi_dcs_write_buffer(dsi, tx, size);
 864
 865	if (tx != stack_tx)
 866		kfree(tx);
 867
 868	return err;
 869}
 870EXPORT_SYMBOL(mipi_dsi_dcs_write);
 871
 872/**
 873 * mipi_dsi_dcs_read() - send DCS read request command
 874 * @dsi: DSI peripheral device
 875 * @cmd: DCS command
 876 * @data: buffer in which to receive data
 877 * @len: size of receive buffer
 878 *
 879 * Return: The number of bytes read or a negative error code on failure.
 880 */
 881ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, u8 cmd, void *data,
 882			  size_t len)
 883{
 884	struct mipi_dsi_msg msg = {
 885		.channel = dsi->channel,
 886		.type = MIPI_DSI_DCS_READ,
 887		.tx_buf = &cmd,
 888		.tx_len = 1,
 889		.rx_buf = data,
 890		.rx_len = len
 891	};
 892
 893	return mipi_dsi_device_transfer(dsi, &msg);
 894}
 895EXPORT_SYMBOL(mipi_dsi_dcs_read);
 896
 897/**
 898 * mipi_dsi_dcs_nop() - send DCS nop packet
 899 * @dsi: DSI peripheral device
 900 *
 901 * Return: 0 on success or a negative error code on failure.
 902 */
 903int mipi_dsi_dcs_nop(struct mipi_dsi_device *dsi)
 904{
 905	ssize_t err;
 906
 907	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_NOP, NULL, 0);
 908	if (err < 0)
 909		return err;
 910
 911	return 0;
 912}
 913EXPORT_SYMBOL(mipi_dsi_dcs_nop);
 914
 915/**
 916 * mipi_dsi_dcs_soft_reset() - perform a software reset of the display module
 917 * @dsi: DSI peripheral device
 918 *
 919 * Return: 0 on success or a negative error code on failure.
 920 */
 921int mipi_dsi_dcs_soft_reset(struct mipi_dsi_device *dsi)
 922{
 923	ssize_t err;
 924
 925	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SOFT_RESET, NULL, 0);
 926	if (err < 0)
 927		return err;
 928
 929	return 0;
 930}
 931EXPORT_SYMBOL(mipi_dsi_dcs_soft_reset);
 932
 933/**
 934 * mipi_dsi_dcs_get_power_mode() - query the display module's current power
 935 *    mode
 936 * @dsi: DSI peripheral device
 937 * @mode: return location for the current power mode
 938 *
 939 * Return: 0 on success or a negative error code on failure.
 940 */
 941int mipi_dsi_dcs_get_power_mode(struct mipi_dsi_device *dsi, u8 *mode)
 942{
 943	ssize_t err;
 944
 945	err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_POWER_MODE, mode,
 946				sizeof(*mode));
 947	if (err <= 0) {
 948		if (err == 0)
 949			err = -ENODATA;
 950
 951		return err;
 952	}
 953
 954	return 0;
 955}
 956EXPORT_SYMBOL(mipi_dsi_dcs_get_power_mode);
 957
 958/**
 959 * mipi_dsi_dcs_get_pixel_format() - gets the pixel format for the RGB image
 960 *    data used by the interface
 961 * @dsi: DSI peripheral device
 962 * @format: return location for the pixel format
 963 *
 964 * Return: 0 on success or a negative error code on failure.
 965 */
 966int mipi_dsi_dcs_get_pixel_format(struct mipi_dsi_device *dsi, u8 *format)
 967{
 968	ssize_t err;
 969
 970	err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_PIXEL_FORMAT, format,
 971				sizeof(*format));
 972	if (err <= 0) {
 973		if (err == 0)
 974			err = -ENODATA;
 975
 976		return err;
 977	}
 978
 979	return 0;
 980}
 981EXPORT_SYMBOL(mipi_dsi_dcs_get_pixel_format);
 982
 983/**
 984 * mipi_dsi_dcs_enter_sleep_mode() - disable all unnecessary blocks inside the
 985 *    display module except interface communication
 986 * @dsi: DSI peripheral device
 987 *
 988 * Return: 0 on success or a negative error code on failure.
 989 */
 990int mipi_dsi_dcs_enter_sleep_mode(struct mipi_dsi_device *dsi)
 991{
 992	ssize_t err;
 993
 994	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_ENTER_SLEEP_MODE, NULL, 0);
 995	if (err < 0)
 996		return err;
 997
 998	return 0;
 999}
1000EXPORT_SYMBOL(mipi_dsi_dcs_enter_sleep_mode);
1001
1002/**
1003 * mipi_dsi_dcs_exit_sleep_mode() - enable all blocks inside the display
1004 *    module
1005 * @dsi: DSI peripheral device
1006 *
1007 * Return: 0 on success or a negative error code on failure.
1008 */
1009int mipi_dsi_dcs_exit_sleep_mode(struct mipi_dsi_device *dsi)
1010{
1011	ssize_t err;
1012
1013	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_EXIT_SLEEP_MODE, NULL, 0);
1014	if (err < 0)
1015		return err;
1016
1017	return 0;
1018}
1019EXPORT_SYMBOL(mipi_dsi_dcs_exit_sleep_mode);
1020
1021/**
1022 * mipi_dsi_dcs_set_display_off() - stop displaying the image data on the
1023 *    display device
1024 * @dsi: DSI peripheral device
1025 *
1026 * Return: 0 on success or a negative error code on failure.
1027 */
1028int mipi_dsi_dcs_set_display_off(struct mipi_dsi_device *dsi)
1029{
1030	ssize_t err;
1031
1032	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_OFF, NULL, 0);
1033	if (err < 0)
1034		return err;
1035
1036	return 0;
1037}
1038EXPORT_SYMBOL(mipi_dsi_dcs_set_display_off);
1039
1040/**
1041 * mipi_dsi_dcs_set_display_on() - start displaying the image data on the
1042 *    display device
1043 * @dsi: DSI peripheral device
1044 *
1045 * Return: 0 on success or a negative error code on failure
1046 */
1047int mipi_dsi_dcs_set_display_on(struct mipi_dsi_device *dsi)
1048{
1049	ssize_t err;
1050
1051	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_ON, NULL, 0);
1052	if (err < 0)
1053		return err;
1054
1055	return 0;
1056}
1057EXPORT_SYMBOL(mipi_dsi_dcs_set_display_on);
1058
1059/**
1060 * mipi_dsi_dcs_set_column_address() - define the column extent of the frame
1061 *    memory accessed by the host processor
1062 * @dsi: DSI peripheral device
1063 * @start: first column of frame memory
1064 * @end: last column of frame memory
1065 *
1066 * Return: 0 on success or a negative error code on failure.
1067 */
1068int mipi_dsi_dcs_set_column_address(struct mipi_dsi_device *dsi, u16 start,
1069				    u16 end)
1070{
1071	u8 payload[4] = { start >> 8, start & 0xff, end >> 8, end & 0xff };
1072	ssize_t err;
1073
1074	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_COLUMN_ADDRESS, payload,
1075				 sizeof(payload));
1076	if (err < 0)
1077		return err;
1078
1079	return 0;
1080}
1081EXPORT_SYMBOL(mipi_dsi_dcs_set_column_address);
1082
1083/**
1084 * mipi_dsi_dcs_set_page_address() - define the page extent of the frame
1085 *    memory accessed by the host processor
1086 * @dsi: DSI peripheral device
1087 * @start: first page of frame memory
1088 * @end: last page of frame memory
1089 *
1090 * Return: 0 on success or a negative error code on failure.
1091 */
1092int mipi_dsi_dcs_set_page_address(struct mipi_dsi_device *dsi, u16 start,
1093				  u16 end)
1094{
1095	u8 payload[4] = { start >> 8, start & 0xff, end >> 8, end & 0xff };
1096	ssize_t err;
1097
1098	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_PAGE_ADDRESS, payload,
1099				 sizeof(payload));
1100	if (err < 0)
1101		return err;
1102
1103	return 0;
1104}
1105EXPORT_SYMBOL(mipi_dsi_dcs_set_page_address);
1106
1107/**
1108 * mipi_dsi_dcs_set_tear_off() - turn off the display module's Tearing Effect
1109 *    output signal on the TE signal line
1110 * @dsi: DSI peripheral device
1111 *
1112 * Return: 0 on success or a negative error code on failure
1113 */
1114int mipi_dsi_dcs_set_tear_off(struct mipi_dsi_device *dsi)
1115{
1116	ssize_t err;
1117
1118	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_OFF, NULL, 0);
1119	if (err < 0)
1120		return err;
1121
1122	return 0;
1123}
1124EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_off);
1125
1126/**
1127 * mipi_dsi_dcs_set_tear_on() - turn on the display module's Tearing Effect
1128 *    output signal on the TE signal line.
1129 * @dsi: DSI peripheral device
1130 * @mode: the Tearing Effect Output Line mode
1131 *
1132 * Return: 0 on success or a negative error code on failure
1133 */
1134int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi,
1135			     enum mipi_dsi_dcs_tear_mode mode)
1136{
1137	u8 value = mode;
1138	ssize_t err;
1139
1140	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_ON, &value,
1141				 sizeof(value));
1142	if (err < 0)
1143		return err;
1144
1145	return 0;
1146}
1147EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_on);
1148
1149/**
1150 * mipi_dsi_dcs_set_pixel_format() - sets the pixel format for the RGB image
1151 *    data used by the interface
1152 * @dsi: DSI peripheral device
1153 * @format: pixel format
1154 *
1155 * Return: 0 on success or a negative error code on failure.
1156 */
1157int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format)
1158{
1159	ssize_t err;
1160
1161	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_PIXEL_FORMAT, &format,
1162				 sizeof(format));
1163	if (err < 0)
1164		return err;
1165
1166	return 0;
1167}
1168EXPORT_SYMBOL(mipi_dsi_dcs_set_pixel_format);
1169
1170/**
1171 * mipi_dsi_dcs_set_tear_scanline() - set the scanline to use as trigger for
1172 *    the Tearing Effect output signal of the display module
1173 * @dsi: DSI peripheral device
1174 * @scanline: scanline to use as trigger
1175 *
1176 * Return: 0 on success or a negative error code on failure
1177 */
1178int mipi_dsi_dcs_set_tear_scanline(struct mipi_dsi_device *dsi, u16 scanline)
1179{
1180	u8 payload[2] = { scanline >> 8, scanline & 0xff };
1181	ssize_t err;
1182
1183	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_SCANLINE, payload,
1184				 sizeof(payload));
1185	if (err < 0)
1186		return err;
1187
1188	return 0;
1189}
1190EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_scanline);
1191
1192/**
1193 * mipi_dsi_dcs_set_display_brightness() - sets the brightness value of the
1194 *    display
1195 * @dsi: DSI peripheral device
1196 * @brightness: brightness value
1197 *
1198 * Return: 0 on success or a negative error code on failure.
1199 */
1200int mipi_dsi_dcs_set_display_brightness(struct mipi_dsi_device *dsi,
1201					u16 brightness)
1202{
1203	u8 payload[2] = { brightness & 0xff, brightness >> 8 };
1204	ssize_t err;
1205
1206	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_BRIGHTNESS,
1207				 payload, sizeof(payload));
1208	if (err < 0)
1209		return err;
1210
1211	return 0;
1212}
1213EXPORT_SYMBOL(mipi_dsi_dcs_set_display_brightness);
1214
1215/**
1216 * mipi_dsi_dcs_get_display_brightness() - gets the current brightness value
1217 *    of the display
1218 * @dsi: DSI peripheral device
1219 * @brightness: brightness value
1220 *
1221 * Return: 0 on success or a negative error code on failure.
1222 */
1223int mipi_dsi_dcs_get_display_brightness(struct mipi_dsi_device *dsi,
1224					u16 *brightness)
1225{
1226	ssize_t err;
1227
1228	err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_DISPLAY_BRIGHTNESS,
1229				brightness, sizeof(*brightness));
1230	if (err <= 0) {
1231		if (err == 0)
1232			err = -ENODATA;
1233
1234		return err;
1235	}
1236
1237	return 0;
1238}
1239EXPORT_SYMBOL(mipi_dsi_dcs_get_display_brightness);
1240
1241/**
1242 * mipi_dsi_dcs_set_display_brightness_large() - sets the 16-bit brightness value
1243 *    of the display
1244 * @dsi: DSI peripheral device
1245 * @brightness: brightness value
1246 *
1247 * Return: 0 on success or a negative error code on failure.
1248 */
1249int mipi_dsi_dcs_set_display_brightness_large(struct mipi_dsi_device *dsi,
1250					     u16 brightness)
1251{
1252	u8 payload[2] = { brightness >> 8, brightness & 0xff };
1253	ssize_t err;
1254
1255	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_BRIGHTNESS,
1256				 payload, sizeof(payload));
1257	if (err < 0)
1258		return err;
1259
1260	return 0;
1261}
1262EXPORT_SYMBOL(mipi_dsi_dcs_set_display_brightness_large);
1263
1264/**
1265 * mipi_dsi_dcs_get_display_brightness_large() - gets the current 16-bit
1266 *    brightness value of the display
1267 * @dsi: DSI peripheral device
1268 * @brightness: brightness value
1269 *
1270 * Return: 0 on success or a negative error code on failure.
1271 */
1272int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi,
1273					     u16 *brightness)
1274{
1275	u8 brightness_be[2];
1276	ssize_t err;
1277
1278	err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_DISPLAY_BRIGHTNESS,
1279				brightness_be, sizeof(brightness_be));
1280	if (err <= 0) {
1281		if (err == 0)
1282			err = -ENODATA;
1283
1284		return err;
1285	}
1286
1287	*brightness = (brightness_be[0] << 8) | brightness_be[1];
1288
1289	return 0;
1290}
1291EXPORT_SYMBOL(mipi_dsi_dcs_get_display_brightness_large);
1292
1293static int mipi_dsi_drv_probe(struct device *dev)
1294{
1295	struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
1296	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
1297
1298	return drv->probe(dsi);
1299}
1300
1301static int mipi_dsi_drv_remove(struct device *dev)
1302{
1303	struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
1304	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
1305
1306	drv->remove(dsi);
1307
1308	return 0;
1309}
1310
1311static void mipi_dsi_drv_shutdown(struct device *dev)
1312{
1313	struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
1314	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
1315
1316	drv->shutdown(dsi);
1317}
1318
1319/**
1320 * mipi_dsi_driver_register_full() - register a driver for DSI devices
1321 * @drv: DSI driver structure
1322 * @owner: owner module
1323 *
1324 * Return: 0 on success or a negative error code on failure.
1325 */
1326int mipi_dsi_driver_register_full(struct mipi_dsi_driver *drv,
1327				  struct module *owner)
1328{
1329	drv->driver.bus = &mipi_dsi_bus_type;
1330	drv->driver.owner = owner;
1331
1332	if (drv->probe)
1333		drv->driver.probe = mipi_dsi_drv_probe;
1334	if (drv->remove)
1335		drv->driver.remove = mipi_dsi_drv_remove;
1336	if (drv->shutdown)
1337		drv->driver.shutdown = mipi_dsi_drv_shutdown;
1338
1339	return driver_register(&drv->driver);
1340}
1341EXPORT_SYMBOL(mipi_dsi_driver_register_full);
1342
1343/**
1344 * mipi_dsi_driver_unregister() - unregister a driver for DSI devices
1345 * @drv: DSI driver structure
1346 *
1347 * Return: 0 on success or a negative error code on failure.
1348 */
1349void mipi_dsi_driver_unregister(struct mipi_dsi_driver *drv)
1350{
1351	driver_unregister(&drv->driver);
1352}
1353EXPORT_SYMBOL(mipi_dsi_driver_unregister);
1354
1355static int __init mipi_dsi_bus_init(void)
1356{
1357	return bus_register(&mipi_dsi_bus_type);
1358}
1359postcore_initcall(mipi_dsi_bus_init);
1360
1361MODULE_AUTHOR("Andrzej Hajda <a.hajda@samsung.com>");
1362MODULE_DESCRIPTION("MIPI DSI Bus");
1363MODULE_LICENSE("GPL and additional rights");