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v5.4
   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 int mipi_dsi_uevent(struct device *dev, struct kobj_uevent_env *env)
  64{
  65	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
  66	int err;
  67
  68	err = of_device_uevent_modalias(dev, env);
  69	if (err != -ENODEV)
  70		return err;
  71
  72	add_uevent_var(env, "MODALIAS=%s%s", MIPI_DSI_MODULE_PREFIX,
  73		       dsi->name);
  74
  75	return 0;
  76}
  77
  78static const struct dev_pm_ops mipi_dsi_device_pm_ops = {
  79	.runtime_suspend = pm_generic_runtime_suspend,
  80	.runtime_resume = pm_generic_runtime_resume,
  81	.suspend = pm_generic_suspend,
  82	.resume = pm_generic_resume,
  83	.freeze = pm_generic_freeze,
  84	.thaw = pm_generic_thaw,
  85	.poweroff = pm_generic_poweroff,
  86	.restore = pm_generic_restore,
  87};
  88
  89static struct bus_type mipi_dsi_bus_type = {
  90	.name = "mipi-dsi",
  91	.match = mipi_dsi_device_match,
  92	.uevent = mipi_dsi_uevent,
  93	.pm = &mipi_dsi_device_pm_ops,
  94};
  95
  96/**
  97 * of_find_mipi_dsi_device_by_node() - find the MIPI DSI device matching a
  98 *    device tree node
  99 * @np: device tree node
 100 *
 101 * Return: A pointer to the MIPI DSI device corresponding to @np or NULL if no
 102 *    such device exists (or has not been registered yet).
 103 */
 104struct mipi_dsi_device *of_find_mipi_dsi_device_by_node(struct device_node *np)
 105{
 106	struct device *dev;
 107
 108	dev = bus_find_device_by_of_node(&mipi_dsi_bus_type, np);
 109
 110	return dev ? to_mipi_dsi_device(dev) : NULL;
 111}
 112EXPORT_SYMBOL(of_find_mipi_dsi_device_by_node);
 113
 114static void mipi_dsi_dev_release(struct device *dev)
 115{
 116	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
 117
 118	of_node_put(dev->of_node);
 119	kfree(dsi);
 120}
 121
 122static const struct device_type mipi_dsi_device_type = {
 123	.release = mipi_dsi_dev_release,
 124};
 125
 126static struct mipi_dsi_device *mipi_dsi_device_alloc(struct mipi_dsi_host *host)
 127{
 128	struct mipi_dsi_device *dsi;
 129
 130	dsi = kzalloc(sizeof(*dsi), GFP_KERNEL);
 131	if (!dsi)
 132		return ERR_PTR(-ENOMEM);
 133
 134	dsi->host = host;
 135	dsi->dev.bus = &mipi_dsi_bus_type;
 136	dsi->dev.parent = host->dev;
 137	dsi->dev.type = &mipi_dsi_device_type;
 138
 139	device_initialize(&dsi->dev);
 140
 141	return dsi;
 142}
 143
 144static int mipi_dsi_device_add(struct mipi_dsi_device *dsi)
 145{
 146	struct mipi_dsi_host *host = dsi->host;
 147
 148	dev_set_name(&dsi->dev, "%s.%d", dev_name(host->dev),  dsi->channel);
 149
 150	return device_add(&dsi->dev);
 151}
 152
 153#if IS_ENABLED(CONFIG_OF)
 154static struct mipi_dsi_device *
 155of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
 156{
 157	struct device *dev = host->dev;
 158	struct mipi_dsi_device_info info = { };
 159	int ret;
 160	u32 reg;
 161
 162	if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) {
 163		dev_err(dev, "modalias failure on %pOF\n", node);
 164		return ERR_PTR(-EINVAL);
 165	}
 166
 167	ret = of_property_read_u32(node, "reg", &reg);
 168	if (ret) {
 169		dev_err(dev, "device node %pOF has no valid reg property: %d\n",
 170			node, ret);
 171		return ERR_PTR(-EINVAL);
 172	}
 173
 174	info.channel = reg;
 175	info.node = of_node_get(node);
 176
 177	return mipi_dsi_device_register_full(host, &info);
 178}
 179#else
 180static struct mipi_dsi_device *
 181of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
 182{
 183	return ERR_PTR(-ENODEV);
 184}
 185#endif
 186
 187/**
 188 * mipi_dsi_device_register_full - create a MIPI DSI device
 189 * @host: DSI host to which this device is connected
 190 * @info: pointer to template containing DSI device information
 191 *
 192 * Create a MIPI DSI device by using the device information provided by
 193 * mipi_dsi_device_info template
 194 *
 195 * Returns:
 196 * A pointer to the newly created MIPI DSI device, or, a pointer encoded
 197 * with an error
 198 */
 199struct mipi_dsi_device *
 200mipi_dsi_device_register_full(struct mipi_dsi_host *host,
 201			      const struct mipi_dsi_device_info *info)
 202{
 203	struct mipi_dsi_device *dsi;
 204	struct device *dev = host->dev;
 205	int ret;
 206
 207	if (!info) {
 208		dev_err(dev, "invalid mipi_dsi_device_info pointer\n");
 209		return ERR_PTR(-EINVAL);
 210	}
 211
 212	if (info->channel > 3) {
 213		dev_err(dev, "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		dev_err(dev, "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		dev_err(dev, "failed to add DSI device %d\n", ret);
 231		kfree(dsi);
 232		return ERR_PTR(ret);
 233	}
 234
 235	return dsi;
 236}
 237EXPORT_SYMBOL(mipi_dsi_device_register_full);
 238
 239/**
 240 * mipi_dsi_device_unregister - unregister MIPI DSI device
 241 * @dsi: DSI peripheral device
 242 */
 243void mipi_dsi_device_unregister(struct mipi_dsi_device *dsi)
 244{
 245	device_unregister(&dsi->dev);
 246}
 247EXPORT_SYMBOL(mipi_dsi_device_unregister);
 248
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 249static DEFINE_MUTEX(host_lock);
 250static 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 */
 261struct 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}
 278EXPORT_SYMBOL(of_find_mipi_dsi_host_by_node);
 279
 280int 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}
 297EXPORT_SYMBOL(mipi_dsi_host_register);
 298
 299static 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
 308void 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}
 316EXPORT_SYMBOL(mipi_dsi_host_unregister);
 317
 318/**
 319 * mipi_dsi_attach - attach a DSI device to its DSI host
 320 * @dsi: DSI peripheral
 321 */
 322int 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}
 331EXPORT_SYMBOL(mipi_dsi_attach);
 332
 333/**
 334 * mipi_dsi_detach - detach a DSI device from its DSI host
 335 * @dsi: DSI peripheral
 336 */
 337int 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}
 346EXPORT_SYMBOL(mipi_dsi_detach);
 347
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 348static 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 */
 369bool 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_END_OF_TRANSMISSION:
 377	case MIPI_DSI_COLOR_MODE_OFF:
 378	case MIPI_DSI_COLOR_MODE_ON:
 379	case MIPI_DSI_SHUTDOWN_PERIPHERAL:
 380	case MIPI_DSI_TURN_ON_PERIPHERAL:
 381	case MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM:
 382	case MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM:
 383	case MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM:
 384	case MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM:
 385	case MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM:
 386	case MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM:
 387	case MIPI_DSI_DCS_SHORT_WRITE:
 388	case MIPI_DSI_DCS_SHORT_WRITE_PARAM:
 389	case MIPI_DSI_DCS_READ:
 390	case MIPI_DSI_DCS_COMPRESSION_MODE:
 391	case MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE:
 392		return true;
 393	}
 394
 395	return false;
 396}
 397EXPORT_SYMBOL(mipi_dsi_packet_format_is_short);
 398
 399/**
 400 * mipi_dsi_packet_format_is_long - check if a packet is of the long format
 401 * @type: MIPI DSI data type of the packet
 402 *
 403 * Return: true if the packet for the given data type is a long packet, false
 404 * otherwise.
 405 */
 406bool mipi_dsi_packet_format_is_long(u8 type)
 407{
 408	switch (type) {
 409	case MIPI_DSI_PPS_LONG_WRITE:
 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_LOOSELY_PACKED_PIXEL_STREAM_YCBCR20:
 415	case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR24:
 416	case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR16:
 417	case MIPI_DSI_PACKED_PIXEL_STREAM_30:
 418	case MIPI_DSI_PACKED_PIXEL_STREAM_36:
 419	case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR12:
 420	case MIPI_DSI_PACKED_PIXEL_STREAM_16:
 421	case MIPI_DSI_PACKED_PIXEL_STREAM_18:
 422	case MIPI_DSI_PIXEL_STREAM_3BYTE_18:
 423	case MIPI_DSI_PACKED_PIXEL_STREAM_24:
 424		return true;
 425	}
 426
 427	return false;
 428}
 429EXPORT_SYMBOL(mipi_dsi_packet_format_is_long);
 430
 431/**
 432 * mipi_dsi_create_packet - create a packet from a message according to the
 433 *     DSI protocol
 434 * @packet: pointer to a DSI packet structure
 435 * @msg: message to translate into a packet
 436 *
 437 * Return: 0 on success or a negative error code on failure.
 438 */
 439int mipi_dsi_create_packet(struct mipi_dsi_packet *packet,
 440			   const struct mipi_dsi_msg *msg)
 441{
 442	if (!packet || !msg)
 443		return -EINVAL;
 444
 445	/* do some minimum sanity checking */
 446	if (!mipi_dsi_packet_format_is_short(msg->type) &&
 447	    !mipi_dsi_packet_format_is_long(msg->type))
 448		return -EINVAL;
 449
 450	if (msg->channel > 3)
 451		return -EINVAL;
 452
 453	memset(packet, 0, sizeof(*packet));
 454	packet->header[0] = ((msg->channel & 0x3) << 6) | (msg->type & 0x3f);
 455
 456	/* TODO: compute ECC if hardware support is not available */
 457
 458	/*
 459	 * Long write packets contain the word count in header bytes 1 and 2.
 460	 * The payload follows the header and is word count bytes long.
 461	 *
 462	 * Short write packets encode up to two parameters in header bytes 1
 463	 * and 2.
 464	 */
 465	if (mipi_dsi_packet_format_is_long(msg->type)) {
 466		packet->header[1] = (msg->tx_len >> 0) & 0xff;
 467		packet->header[2] = (msg->tx_len >> 8) & 0xff;
 468
 469		packet->payload_length = msg->tx_len;
 470		packet->payload = msg->tx_buf;
 471	} else {
 472		const u8 *tx = msg->tx_buf;
 473
 474		packet->header[1] = (msg->tx_len > 0) ? tx[0] : 0;
 475		packet->header[2] = (msg->tx_len > 1) ? tx[1] : 0;
 476	}
 477
 478	packet->size = sizeof(packet->header) + packet->payload_length;
 479
 480	return 0;
 481}
 482EXPORT_SYMBOL(mipi_dsi_create_packet);
 483
 484/**
 485 * mipi_dsi_shutdown_peripheral() - sends a Shutdown Peripheral command
 486 * @dsi: DSI peripheral device
 487 *
 488 * Return: 0 on success or a negative error code on failure.
 489 */
 490int mipi_dsi_shutdown_peripheral(struct mipi_dsi_device *dsi)
 491{
 492	struct mipi_dsi_msg msg = {
 493		.channel = dsi->channel,
 494		.type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
 495		.tx_buf = (u8 [2]) { 0, 0 },
 496		.tx_len = 2,
 497	};
 498	int ret = mipi_dsi_device_transfer(dsi, &msg);
 499
 500	return (ret < 0) ? ret : 0;
 501}
 502EXPORT_SYMBOL(mipi_dsi_shutdown_peripheral);
 503
 504/**
 505 * mipi_dsi_turn_on_peripheral() - sends a Turn On Peripheral command
 506 * @dsi: DSI peripheral device
 507 *
 508 * Return: 0 on success or a negative error code on failure.
 509 */
 510int mipi_dsi_turn_on_peripheral(struct mipi_dsi_device *dsi)
 511{
 512	struct mipi_dsi_msg msg = {
 513		.channel = dsi->channel,
 514		.type = MIPI_DSI_TURN_ON_PERIPHERAL,
 515		.tx_buf = (u8 [2]) { 0, 0 },
 516		.tx_len = 2,
 517	};
 518	int ret = mipi_dsi_device_transfer(dsi, &msg);
 519
 520	return (ret < 0) ? ret : 0;
 521}
 522EXPORT_SYMBOL(mipi_dsi_turn_on_peripheral);
 523
 524/*
 525 * mipi_dsi_set_maximum_return_packet_size() - specify the maximum size of the
 526 *    the payload in a long packet transmitted from the peripheral back to the
 527 *    host processor
 528 * @dsi: DSI peripheral device
 529 * @value: the maximum size of the payload
 530 *
 531 * Return: 0 on success or a negative error code on failure.
 532 */
 533int mipi_dsi_set_maximum_return_packet_size(struct mipi_dsi_device *dsi,
 534					    u16 value)
 535{
 536	u8 tx[2] = { value & 0xff, value >> 8 };
 537	struct mipi_dsi_msg msg = {
 538		.channel = dsi->channel,
 539		.type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
 540		.tx_len = sizeof(tx),
 541		.tx_buf = tx,
 542	};
 543	int ret = mipi_dsi_device_transfer(dsi, &msg);
 544
 545	return (ret < 0) ? ret : 0;
 546}
 547EXPORT_SYMBOL(mipi_dsi_set_maximum_return_packet_size);
 548
 549/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 550 * mipi_dsi_generic_write() - transmit data using a generic write packet
 551 * @dsi: DSI peripheral device
 552 * @payload: buffer containing the payload
 553 * @size: size of payload buffer
 554 *
 555 * This function will automatically choose the right data type depending on
 556 * the payload length.
 557 *
 558 * Return: The number of bytes transmitted on success or a negative error code
 559 * on failure.
 560 */
 561ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload,
 562			       size_t size)
 563{
 564	struct mipi_dsi_msg msg = {
 565		.channel = dsi->channel,
 566		.tx_buf = payload,
 567		.tx_len = size
 568	};
 569
 570	switch (size) {
 571	case 0:
 572		msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
 573		break;
 574
 575	case 1:
 576		msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
 577		break;
 578
 579	case 2:
 580		msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
 581		break;
 582
 583	default:
 584		msg.type = MIPI_DSI_GENERIC_LONG_WRITE;
 585		break;
 586	}
 587
 588	return mipi_dsi_device_transfer(dsi, &msg);
 589}
 590EXPORT_SYMBOL(mipi_dsi_generic_write);
 591
 592/**
 593 * mipi_dsi_generic_read() - receive data using a generic read packet
 594 * @dsi: DSI peripheral device
 595 * @params: buffer containing the request parameters
 596 * @num_params: number of request parameters
 597 * @data: buffer in which to return the received data
 598 * @size: size of receive buffer
 599 *
 600 * This function will automatically choose the right data type depending on
 601 * the number of parameters passed in.
 602 *
 603 * Return: The number of bytes successfully read or a negative error code on
 604 * failure.
 605 */
 606ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params,
 607			      size_t num_params, void *data, size_t size)
 608{
 609	struct mipi_dsi_msg msg = {
 610		.channel = dsi->channel,
 611		.tx_len = num_params,
 612		.tx_buf = params,
 613		.rx_len = size,
 614		.rx_buf = data
 615	};
 616
 617	switch (num_params) {
 618	case 0:
 619		msg.type = MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM;
 620		break;
 621
 622	case 1:
 623		msg.type = MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM;
 624		break;
 625
 626	case 2:
 627		msg.type = MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM;
 628		break;
 629
 630	default:
 631		return -EINVAL;
 632	}
 633
 634	return mipi_dsi_device_transfer(dsi, &msg);
 635}
 636EXPORT_SYMBOL(mipi_dsi_generic_read);
 637
 638/**
 639 * mipi_dsi_dcs_write_buffer() - transmit a DCS command with payload
 640 * @dsi: DSI peripheral device
 641 * @data: buffer containing data to be transmitted
 642 * @len: size of transmission buffer
 643 *
 644 * This function will automatically choose the right data type depending on
 645 * the command payload length.
 646 *
 647 * Return: The number of bytes successfully transmitted or a negative error
 648 * code on failure.
 649 */
 650ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi,
 651				  const void *data, size_t len)
 652{
 653	struct mipi_dsi_msg msg = {
 654		.channel = dsi->channel,
 655		.tx_buf = data,
 656		.tx_len = len
 657	};
 658
 659	switch (len) {
 660	case 0:
 661		return -EINVAL;
 662
 663	case 1:
 664		msg.type = MIPI_DSI_DCS_SHORT_WRITE;
 665		break;
 666
 667	case 2:
 668		msg.type = MIPI_DSI_DCS_SHORT_WRITE_PARAM;
 669		break;
 670
 671	default:
 672		msg.type = MIPI_DSI_DCS_LONG_WRITE;
 673		break;
 674	}
 675
 676	return mipi_dsi_device_transfer(dsi, &msg);
 677}
 678EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer);
 679
 680/**
 681 * mipi_dsi_dcs_write() - send DCS write command
 682 * @dsi: DSI peripheral device
 683 * @cmd: DCS command
 684 * @data: buffer containing the command payload
 685 * @len: command payload length
 686 *
 687 * This function will automatically choose the right data type depending on
 688 * the command payload length.
 689 *
 690 * Return: The number of bytes successfully transmitted or a negative error
 691 * code on failure.
 692 */
 693ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd,
 694			   const void *data, size_t len)
 695{
 696	ssize_t err;
 697	size_t size;
 
 698	u8 *tx;
 699
 700	if (len > 0) {
 701		size = 1 + len;
 702
 703		tx = kmalloc(size, GFP_KERNEL);
 704		if (!tx)
 705			return -ENOMEM;
 706
 707		/* concatenate the DCS command byte and the payload */
 708		tx[0] = cmd;
 709		memcpy(&tx[1], data, len);
 710	} else {
 711		tx = &cmd;
 712		size = 1;
 713	}
 714
 
 
 
 
 
 715	err = mipi_dsi_dcs_write_buffer(dsi, tx, size);
 716
 717	if (len > 0)
 718		kfree(tx);
 719
 720	return err;
 721}
 722EXPORT_SYMBOL(mipi_dsi_dcs_write);
 723
 724/**
 725 * mipi_dsi_dcs_read() - send DCS read request command
 726 * @dsi: DSI peripheral device
 727 * @cmd: DCS command
 728 * @data: buffer in which to receive data
 729 * @len: size of receive buffer
 730 *
 731 * Return: The number of bytes read or a negative error code on failure.
 732 */
 733ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, u8 cmd, void *data,
 734			  size_t len)
 735{
 736	struct mipi_dsi_msg msg = {
 737		.channel = dsi->channel,
 738		.type = MIPI_DSI_DCS_READ,
 739		.tx_buf = &cmd,
 740		.tx_len = 1,
 741		.rx_buf = data,
 742		.rx_len = len
 743	};
 744
 745	return mipi_dsi_device_transfer(dsi, &msg);
 746}
 747EXPORT_SYMBOL(mipi_dsi_dcs_read);
 748
 749/**
 750 * mipi_dsi_dcs_nop() - send DCS nop packet
 751 * @dsi: DSI peripheral device
 752 *
 753 * Return: 0 on success or a negative error code on failure.
 754 */
 755int mipi_dsi_dcs_nop(struct mipi_dsi_device *dsi)
 756{
 757	ssize_t err;
 758
 759	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_NOP, NULL, 0);
 760	if (err < 0)
 761		return err;
 762
 763	return 0;
 764}
 765EXPORT_SYMBOL(mipi_dsi_dcs_nop);
 766
 767/**
 768 * mipi_dsi_dcs_soft_reset() - perform a software reset of the display module
 769 * @dsi: DSI peripheral device
 770 *
 771 * Return: 0 on success or a negative error code on failure.
 772 */
 773int mipi_dsi_dcs_soft_reset(struct mipi_dsi_device *dsi)
 774{
 775	ssize_t err;
 776
 777	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SOFT_RESET, NULL, 0);
 778	if (err < 0)
 779		return err;
 780
 781	return 0;
 782}
 783EXPORT_SYMBOL(mipi_dsi_dcs_soft_reset);
 784
 785/**
 786 * mipi_dsi_dcs_get_power_mode() - query the display module's current power
 787 *    mode
 788 * @dsi: DSI peripheral device
 789 * @mode: return location for the current power mode
 790 *
 791 * Return: 0 on success or a negative error code on failure.
 792 */
 793int mipi_dsi_dcs_get_power_mode(struct mipi_dsi_device *dsi, u8 *mode)
 794{
 795	ssize_t err;
 796
 797	err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_POWER_MODE, mode,
 798				sizeof(*mode));
 799	if (err <= 0) {
 800		if (err == 0)
 801			err = -ENODATA;
 802
 803		return err;
 804	}
 805
 806	return 0;
 807}
 808EXPORT_SYMBOL(mipi_dsi_dcs_get_power_mode);
 809
 810/**
 811 * mipi_dsi_dcs_get_pixel_format() - gets the pixel format for the RGB image
 812 *    data used by the interface
 813 * @dsi: DSI peripheral device
 814 * @format: return location for the pixel format
 815 *
 816 * Return: 0 on success or a negative error code on failure.
 817 */
 818int mipi_dsi_dcs_get_pixel_format(struct mipi_dsi_device *dsi, u8 *format)
 819{
 820	ssize_t err;
 821
 822	err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_PIXEL_FORMAT, format,
 823				sizeof(*format));
 824	if (err <= 0) {
 825		if (err == 0)
 826			err = -ENODATA;
 827
 828		return err;
 829	}
 830
 831	return 0;
 832}
 833EXPORT_SYMBOL(mipi_dsi_dcs_get_pixel_format);
 834
 835/**
 836 * mipi_dsi_dcs_enter_sleep_mode() - disable all unnecessary blocks inside the
 837 *    display module except interface communication
 838 * @dsi: DSI peripheral device
 839 *
 840 * Return: 0 on success or a negative error code on failure.
 841 */
 842int mipi_dsi_dcs_enter_sleep_mode(struct mipi_dsi_device *dsi)
 843{
 844	ssize_t err;
 845
 846	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_ENTER_SLEEP_MODE, NULL, 0);
 847	if (err < 0)
 848		return err;
 849
 850	return 0;
 851}
 852EXPORT_SYMBOL(mipi_dsi_dcs_enter_sleep_mode);
 853
 854/**
 855 * mipi_dsi_dcs_exit_sleep_mode() - enable all blocks inside the display
 856 *    module
 857 * @dsi: DSI peripheral device
 858 *
 859 * Return: 0 on success or a negative error code on failure.
 860 */
 861int mipi_dsi_dcs_exit_sleep_mode(struct mipi_dsi_device *dsi)
 862{
 863	ssize_t err;
 864
 865	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_EXIT_SLEEP_MODE, NULL, 0);
 866	if (err < 0)
 867		return err;
 868
 869	return 0;
 870}
 871EXPORT_SYMBOL(mipi_dsi_dcs_exit_sleep_mode);
 872
 873/**
 874 * mipi_dsi_dcs_set_display_off() - stop displaying the image data on the
 875 *    display device
 876 * @dsi: DSI peripheral device
 877 *
 878 * Return: 0 on success or a negative error code on failure.
 879 */
 880int mipi_dsi_dcs_set_display_off(struct mipi_dsi_device *dsi)
 881{
 882	ssize_t err;
 883
 884	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_OFF, NULL, 0);
 885	if (err < 0)
 886		return err;
 887
 888	return 0;
 889}
 890EXPORT_SYMBOL(mipi_dsi_dcs_set_display_off);
 891
 892/**
 893 * mipi_dsi_dcs_set_display_on() - start displaying the image data on the
 894 *    display device
 895 * @dsi: DSI peripheral device
 896 *
 897 * Return: 0 on success or a negative error code on failure
 898 */
 899int mipi_dsi_dcs_set_display_on(struct mipi_dsi_device *dsi)
 900{
 901	ssize_t err;
 902
 903	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_ON, NULL, 0);
 904	if (err < 0)
 905		return err;
 906
 907	return 0;
 908}
 909EXPORT_SYMBOL(mipi_dsi_dcs_set_display_on);
 910
 911/**
 912 * mipi_dsi_dcs_set_column_address() - define the column extent of the frame
 913 *    memory accessed by the host processor
 914 * @dsi: DSI peripheral device
 915 * @start: first column of frame memory
 916 * @end: last column of frame memory
 917 *
 918 * Return: 0 on success or a negative error code on failure.
 919 */
 920int mipi_dsi_dcs_set_column_address(struct mipi_dsi_device *dsi, u16 start,
 921				    u16 end)
 922{
 923	u8 payload[4] = { start >> 8, start & 0xff, end >> 8, end & 0xff };
 924	ssize_t err;
 925
 926	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_COLUMN_ADDRESS, payload,
 927				 sizeof(payload));
 928	if (err < 0)
 929		return err;
 930
 931	return 0;
 932}
 933EXPORT_SYMBOL(mipi_dsi_dcs_set_column_address);
 934
 935/**
 936 * mipi_dsi_dcs_set_page_address() - define the page extent of the frame
 937 *    memory accessed by the host processor
 938 * @dsi: DSI peripheral device
 939 * @start: first page of frame memory
 940 * @end: last page of frame memory
 941 *
 942 * Return: 0 on success or a negative error code on failure.
 943 */
 944int mipi_dsi_dcs_set_page_address(struct mipi_dsi_device *dsi, u16 start,
 945				  u16 end)
 946{
 947	u8 payload[4] = { start >> 8, start & 0xff, end >> 8, end & 0xff };
 948	ssize_t err;
 949
 950	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_PAGE_ADDRESS, payload,
 951				 sizeof(payload));
 952	if (err < 0)
 953		return err;
 954
 955	return 0;
 956}
 957EXPORT_SYMBOL(mipi_dsi_dcs_set_page_address);
 958
 959/**
 960 * mipi_dsi_dcs_set_tear_off() - turn off the display module's Tearing Effect
 961 *    output signal on the TE signal line
 962 * @dsi: DSI peripheral device
 963 *
 964 * Return: 0 on success or a negative error code on failure
 965 */
 966int mipi_dsi_dcs_set_tear_off(struct mipi_dsi_device *dsi)
 967{
 968	ssize_t err;
 969
 970	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_OFF, NULL, 0);
 971	if (err < 0)
 972		return err;
 973
 974	return 0;
 975}
 976EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_off);
 977
 978/**
 979 * mipi_dsi_dcs_set_tear_on() - turn on the display module's Tearing Effect
 980 *    output signal on the TE signal line.
 981 * @dsi: DSI peripheral device
 982 * @mode: the Tearing Effect Output Line mode
 983 *
 984 * Return: 0 on success or a negative error code on failure
 985 */
 986int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi,
 987			     enum mipi_dsi_dcs_tear_mode mode)
 988{
 989	u8 value = mode;
 990	ssize_t err;
 991
 992	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_ON, &value,
 993				 sizeof(value));
 994	if (err < 0)
 995		return err;
 996
 997	return 0;
 998}
 999EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_on);
1000
1001/**
1002 * mipi_dsi_dcs_set_pixel_format() - sets the pixel format for the RGB image
1003 *    data used by the interface
1004 * @dsi: DSI peripheral device
1005 * @format: pixel format
1006 *
1007 * Return: 0 on success or a negative error code on failure.
1008 */
1009int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format)
1010{
1011	ssize_t err;
1012
1013	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_PIXEL_FORMAT, &format,
1014				 sizeof(format));
1015	if (err < 0)
1016		return err;
1017
1018	return 0;
1019}
1020EXPORT_SYMBOL(mipi_dsi_dcs_set_pixel_format);
1021
1022/**
1023 * mipi_dsi_dcs_set_tear_scanline() - set the scanline to use as trigger for
1024 *    the Tearing Effect output signal of the display module
1025 * @dsi: DSI peripheral device
1026 * @scanline: scanline to use as trigger
1027 *
1028 * Return: 0 on success or a negative error code on failure
1029 */
1030int mipi_dsi_dcs_set_tear_scanline(struct mipi_dsi_device *dsi, u16 scanline)
1031{
1032	u8 payload[3] = { MIPI_DCS_SET_TEAR_SCANLINE, scanline >> 8,
1033			  scanline & 0xff };
1034	ssize_t err;
1035
1036	err = mipi_dsi_generic_write(dsi, payload, sizeof(payload));
 
1037	if (err < 0)
1038		return err;
1039
1040	return 0;
1041}
1042EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_scanline);
1043
1044/**
1045 * mipi_dsi_dcs_set_display_brightness() - sets the brightness value of the
1046 *    display
1047 * @dsi: DSI peripheral device
1048 * @brightness: brightness value
1049 *
1050 * Return: 0 on success or a negative error code on failure.
1051 */
1052int mipi_dsi_dcs_set_display_brightness(struct mipi_dsi_device *dsi,
1053					u16 brightness)
1054{
1055	u8 payload[2] = { brightness & 0xff, brightness >> 8 };
1056	ssize_t err;
1057
1058	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_BRIGHTNESS,
1059				 payload, sizeof(payload));
1060	if (err < 0)
1061		return err;
1062
1063	return 0;
1064}
1065EXPORT_SYMBOL(mipi_dsi_dcs_set_display_brightness);
1066
1067/**
1068 * mipi_dsi_dcs_get_display_brightness() - gets the current brightness value
1069 *    of the display
1070 * @dsi: DSI peripheral device
1071 * @brightness: brightness value
1072 *
1073 * Return: 0 on success or a negative error code on failure.
1074 */
1075int mipi_dsi_dcs_get_display_brightness(struct mipi_dsi_device *dsi,
1076					u16 *brightness)
1077{
1078	ssize_t err;
1079
1080	err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_DISPLAY_BRIGHTNESS,
1081				brightness, sizeof(*brightness));
1082	if (err <= 0) {
1083		if (err == 0)
1084			err = -ENODATA;
1085
1086		return err;
1087	}
1088
1089	return 0;
1090}
1091EXPORT_SYMBOL(mipi_dsi_dcs_get_display_brightness);
1092
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1093static int mipi_dsi_drv_probe(struct device *dev)
1094{
1095	struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
1096	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
1097
1098	return drv->probe(dsi);
1099}
1100
1101static int mipi_dsi_drv_remove(struct device *dev)
1102{
1103	struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
1104	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
1105
1106	return drv->remove(dsi);
 
 
1107}
1108
1109static void mipi_dsi_drv_shutdown(struct device *dev)
1110{
1111	struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
1112	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
1113
1114	drv->shutdown(dsi);
1115}
1116
1117/**
1118 * mipi_dsi_driver_register_full() - register a driver for DSI devices
1119 * @drv: DSI driver structure
1120 * @owner: owner module
1121 *
1122 * Return: 0 on success or a negative error code on failure.
1123 */
1124int mipi_dsi_driver_register_full(struct mipi_dsi_driver *drv,
1125				  struct module *owner)
1126{
1127	drv->driver.bus = &mipi_dsi_bus_type;
1128	drv->driver.owner = owner;
1129
1130	if (drv->probe)
1131		drv->driver.probe = mipi_dsi_drv_probe;
1132	if (drv->remove)
1133		drv->driver.remove = mipi_dsi_drv_remove;
1134	if (drv->shutdown)
1135		drv->driver.shutdown = mipi_dsi_drv_shutdown;
1136
1137	return driver_register(&drv->driver);
1138}
1139EXPORT_SYMBOL(mipi_dsi_driver_register_full);
1140
1141/**
1142 * mipi_dsi_driver_unregister() - unregister a driver for DSI devices
1143 * @drv: DSI driver structure
1144 *
1145 * Return: 0 on success or a negative error code on failure.
1146 */
1147void mipi_dsi_driver_unregister(struct mipi_dsi_driver *drv)
1148{
1149	driver_unregister(&drv->driver);
1150}
1151EXPORT_SYMBOL(mipi_dsi_driver_unregister);
1152
1153static int __init mipi_dsi_bus_init(void)
1154{
1155	return bus_register(&mipi_dsi_bus_type);
1156}
1157postcore_initcall(mipi_dsi_bus_init);
1158
1159MODULE_AUTHOR("Andrzej Hajda <a.hajda@samsung.com>");
1160MODULE_DESCRIPTION("MIPI DSI Bus");
1161MODULE_LICENSE("GPL and additional rights");
v6.9.4
   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 const 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 */
 657int 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 */
 682int 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");