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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * MIPI Display Bus Interface (DBI) LCD controller support4 *5 * Copyright 2016 Noralf Trønnes6 */7 8#include <linux/backlight.h>9#include <linux/debugfs.h>10#include <linux/delay.h>11#include <linux/gpio/consumer.h>12#include <linux/module.h>13#include <linux/regulator/consumer.h>14#include <linux/spi/spi.h>15 16#include <drm/drm_connector.h>17#include <drm/drm_damage_helper.h>18#include <drm/drm_drv.h>19#include <drm/drm_file.h>20#include <drm/drm_format_helper.h>21#include <drm/drm_fourcc.h>22#include <drm/drm_framebuffer.h>23#include <drm/drm_gem.h>24#include <drm/drm_gem_atomic_helper.h>25#include <drm/drm_gem_framebuffer_helper.h>26#include <drm/drm_mipi_dbi.h>27#include <drm/drm_modes.h>28#include <drm/drm_probe_helper.h>29#include <drm/drm_rect.h>30#include <video/mipi_display.h>31 32#define MIPI_DBI_MAX_SPI_READ_SPEED 2000000 /* 2MHz */33 34#define DCS_POWER_MODE_DISPLAY			BIT(2)35#define DCS_POWER_MODE_DISPLAY_NORMAL_MODE	BIT(3)36#define DCS_POWER_MODE_SLEEP_MODE		BIT(4)37#define DCS_POWER_MODE_PARTIAL_MODE		BIT(5)38#define DCS_POWER_MODE_IDLE_MODE		BIT(6)39#define DCS_POWER_MODE_RESERVED_MASK		(BIT(0) | BIT(1) | BIT(7))40 41/**42 * DOC: overview43 *44 * This library provides helpers for MIPI Display Bus Interface (DBI)45 * compatible display controllers.46 *47 * Many controllers for tiny lcd displays are MIPI compliant and can use this48 * library. If a controller uses registers 0x2A and 0x2B to set the area to49 * update and uses register 0x2C to write to frame memory, it is most likely50 * MIPI compliant.51 *52 * Only MIPI Type 1 displays are supported since a full frame memory is needed.53 *54 * There are 3 MIPI DBI implementation types:55 *56 * A. Motorola 6800 type parallel bus57 *58 * B. Intel 8080 type parallel bus59 *60 * C. SPI type with 3 options:61 *62 *    1. 9-bit with the Data/Command signal as the ninth bit63 *    2. Same as above except it's sent as 16 bits64 *    3. 8-bit with the Data/Command signal as a separate D/CX pin65 *66 * Currently mipi_dbi only supports Type C options 1 and 3 with67 * mipi_dbi_spi_init().68 */69 70#define MIPI_DBI_DEBUG_COMMAND(cmd, data, len) \71({ \72	if (!len) \73		DRM_DEBUG_DRIVER("cmd=%02x\n", cmd); \74	else if (len <= 32) \75		DRM_DEBUG_DRIVER("cmd=%02x, par=%*ph\n", cmd, (int)len, data);\76	else \77		DRM_DEBUG_DRIVER("cmd=%02x, len=%zu\n", cmd, len); \78})79 80static const u8 mipi_dbi_dcs_read_commands[] = {81	MIPI_DCS_GET_DISPLAY_ID,82	MIPI_DCS_GET_RED_CHANNEL,83	MIPI_DCS_GET_GREEN_CHANNEL,84	MIPI_DCS_GET_BLUE_CHANNEL,85	MIPI_DCS_GET_DISPLAY_STATUS,86	MIPI_DCS_GET_POWER_MODE,87	MIPI_DCS_GET_ADDRESS_MODE,88	MIPI_DCS_GET_PIXEL_FORMAT,89	MIPI_DCS_GET_DISPLAY_MODE,90	MIPI_DCS_GET_SIGNAL_MODE,91	MIPI_DCS_GET_DIAGNOSTIC_RESULT,92	MIPI_DCS_READ_MEMORY_START,93	MIPI_DCS_READ_MEMORY_CONTINUE,94	MIPI_DCS_GET_SCANLINE,95	MIPI_DCS_GET_DISPLAY_BRIGHTNESS,96	MIPI_DCS_GET_CONTROL_DISPLAY,97	MIPI_DCS_GET_POWER_SAVE,98	MIPI_DCS_GET_CABC_MIN_BRIGHTNESS,99	MIPI_DCS_READ_DDB_START,100	MIPI_DCS_READ_DDB_CONTINUE,101	0, /* sentinel */102};103 104static bool mipi_dbi_command_is_read(struct mipi_dbi *dbi, u8 cmd)105{106	unsigned int i;107 108	if (!dbi->read_commands)109		return false;110 111	for (i = 0; i < 0xff; i++) {112		if (!dbi->read_commands[i])113			return false;114		if (cmd == dbi->read_commands[i])115			return true;116	}117 118	return false;119}120 121/**122 * mipi_dbi_command_read - MIPI DCS read command123 * @dbi: MIPI DBI structure124 * @cmd: Command125 * @val: Value read126 *127 * Send MIPI DCS read command to the controller.128 *129 * Returns:130 * Zero on success, negative error code on failure.131 */132int mipi_dbi_command_read(struct mipi_dbi *dbi, u8 cmd, u8 *val)133{134	if (!dbi->read_commands)135		return -EACCES;136 137	if (!mipi_dbi_command_is_read(dbi, cmd))138		return -EINVAL;139 140	return mipi_dbi_command_buf(dbi, cmd, val, 1);141}142EXPORT_SYMBOL(mipi_dbi_command_read);143 144/**145 * mipi_dbi_command_buf - MIPI DCS command with parameter(s) in an array146 * @dbi: MIPI DBI structure147 * @cmd: Command148 * @data: Parameter buffer149 * @len: Buffer length150 *151 * Returns:152 * Zero on success, negative error code on failure.153 */154int mipi_dbi_command_buf(struct mipi_dbi *dbi, u8 cmd, u8 *data, size_t len)155{156	u8 *cmdbuf;157	int ret;158 159	/* SPI requires dma-safe buffers */160	cmdbuf = kmemdup(&cmd, 1, GFP_KERNEL);161	if (!cmdbuf)162		return -ENOMEM;163 164	mutex_lock(&dbi->cmdlock);165	ret = dbi->command(dbi, cmdbuf, data, len);166	mutex_unlock(&dbi->cmdlock);167 168	kfree(cmdbuf);169 170	return ret;171}172EXPORT_SYMBOL(mipi_dbi_command_buf);173 174/* This should only be used by mipi_dbi_command() */175int mipi_dbi_command_stackbuf(struct mipi_dbi *dbi, u8 cmd, const u8 *data,176			      size_t len)177{178	u8 *buf;179	int ret;180 181	buf = kmemdup(data, len, GFP_KERNEL);182	if (!buf)183		return -ENOMEM;184 185	ret = mipi_dbi_command_buf(dbi, cmd, buf, len);186 187	kfree(buf);188 189	return ret;190}191EXPORT_SYMBOL(mipi_dbi_command_stackbuf);192 193/**194 * mipi_dbi_buf_copy - Copy a framebuffer, transforming it if necessary195 * @dst: The destination buffer196 * @src: The source buffer197 * @fb: The source framebuffer198 * @clip: Clipping rectangle of the area to be copied199 * @swap: When true, swap MSB/LSB of 16-bit values200 * @fmtcnv_state: Format-conversion state201 *202 * Returns:203 * Zero on success, negative error code on failure.204 */205int mipi_dbi_buf_copy(void *dst, struct iosys_map *src, struct drm_framebuffer *fb,206		      struct drm_rect *clip, bool swap,207		      struct drm_format_conv_state *fmtcnv_state)208{209	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);210	struct drm_gem_object *gem = drm_gem_fb_get_obj(fb, 0);211	struct iosys_map dst_map = IOSYS_MAP_INIT_VADDR(dst);212	int ret;213 214	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);215	if (ret)216		return ret;217 218	switch (fb->format->format) {219	case DRM_FORMAT_RGB565:220		if (swap)221			drm_fb_swab(&dst_map, NULL, src, fb, clip, !gem->import_attach,222				    fmtcnv_state);223		else224			drm_fb_memcpy(&dst_map, NULL, src, fb, clip);225		break;226	case DRM_FORMAT_RGB888:227		drm_fb_memcpy(&dst_map, NULL, src, fb, clip);228		break;229	case DRM_FORMAT_XRGB8888:230		switch (dbidev->pixel_format) {231		case DRM_FORMAT_RGB565:232			drm_fb_xrgb8888_to_rgb565(&dst_map, NULL, src, fb, clip, fmtcnv_state, swap);233			break;234		case DRM_FORMAT_RGB888:235			drm_fb_xrgb8888_to_rgb888(&dst_map, NULL, src, fb, clip, fmtcnv_state);236			break;237		}238		break;239	default:240		drm_err_once(fb->dev, "Format is not supported: %p4cc\n",241			     &fb->format->format);242		ret = -EINVAL;243	}244 245	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);246 247	return ret;248}249EXPORT_SYMBOL(mipi_dbi_buf_copy);250 251static void mipi_dbi_set_window_address(struct mipi_dbi_dev *dbidev,252					unsigned int xs, unsigned int xe,253					unsigned int ys, unsigned int ye)254{255	struct mipi_dbi *dbi = &dbidev->dbi;256 257	xs += dbidev->left_offset;258	xe += dbidev->left_offset;259	ys += dbidev->top_offset;260	ye += dbidev->top_offset;261 262	mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS, (xs >> 8) & 0xff,263			 xs & 0xff, (xe >> 8) & 0xff, xe & 0xff);264	mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS, (ys >> 8) & 0xff,265			 ys & 0xff, (ye >> 8) & 0xff, ye & 0xff);266}267 268static void mipi_dbi_fb_dirty(struct iosys_map *src, struct drm_framebuffer *fb,269			      struct drm_rect *rect, struct drm_format_conv_state *fmtcnv_state)270{271	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);272	unsigned int height = rect->y2 - rect->y1;273	unsigned int width = rect->x2 - rect->x1;274	const struct drm_format_info *dst_format;275	struct mipi_dbi *dbi = &dbidev->dbi;276	bool swap = dbi->swap_bytes;277	int ret = 0;278	size_t len;279	bool full;280	void *tr;281 282	full = width == fb->width && height == fb->height;283 284	DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));285 286	if (!dbi->dc || !full || swap ||287	    fb->format->format == DRM_FORMAT_XRGB8888) {288		tr = dbidev->tx_buf;289		ret = mipi_dbi_buf_copy(tr, src, fb, rect, swap, fmtcnv_state);290		if (ret)291			goto err_msg;292	} else {293		tr = src->vaddr; /* TODO: Use mapping abstraction properly */294	}295 296	mipi_dbi_set_window_address(dbidev, rect->x1, rect->x2 - 1, rect->y1,297				    rect->y2 - 1);298 299	if (fb->format->format == DRM_FORMAT_XRGB8888)300		dst_format = drm_format_info(dbidev->pixel_format);301	else302		dst_format = fb->format;303	len = drm_format_info_min_pitch(dst_format, 0, width) * height;304 305	ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, tr, len);306err_msg:307	if (ret)308		drm_err_once(fb->dev, "Failed to update display %d\n", ret);309}310 311/**312 * mipi_dbi_pipe_mode_valid - MIPI DBI mode-valid helper313 * @pipe: Simple display pipe314 * @mode: The mode to test315 *316 * This function validates a given display mode against the MIPI DBI's hardware317 * display. Drivers can use this as their &drm_simple_display_pipe_funcs->mode_valid318 * callback.319 */320enum drm_mode_status mipi_dbi_pipe_mode_valid(struct drm_simple_display_pipe *pipe,321					      const struct drm_display_mode *mode)322{323	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);324 325	return drm_crtc_helper_mode_valid_fixed(&pipe->crtc, mode, &dbidev->mode);326}327EXPORT_SYMBOL(mipi_dbi_pipe_mode_valid);328 329/**330 * mipi_dbi_pipe_update - Display pipe update helper331 * @pipe: Simple display pipe332 * @old_state: Old plane state333 *334 * This function handles framebuffer flushing and vblank events. Drivers can use335 * this as their &drm_simple_display_pipe_funcs->update callback.336 */337void mipi_dbi_pipe_update(struct drm_simple_display_pipe *pipe,338			  struct drm_plane_state *old_state)339{340	struct drm_plane_state *state = pipe->plane.state;341	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);342	struct drm_framebuffer *fb = state->fb;343	struct drm_rect rect;344	int idx;345 346	if (!pipe->crtc.state->active)347		return;348 349	if (WARN_ON(!fb))350		return;351 352	if (!drm_dev_enter(fb->dev, &idx))353		return;354 355	if (drm_atomic_helper_damage_merged(old_state, state, &rect))356		mipi_dbi_fb_dirty(&shadow_plane_state->data[0], fb, &rect,357				  &shadow_plane_state->fmtcnv_state);358 359	drm_dev_exit(idx);360}361EXPORT_SYMBOL(mipi_dbi_pipe_update);362 363/**364 * mipi_dbi_enable_flush - MIPI DBI enable helper365 * @dbidev: MIPI DBI device structure366 * @crtc_state: CRTC state367 * @plane_state: Plane state368 *369 * Flushes the whole framebuffer and enables the backlight. Drivers can use this370 * in their &drm_simple_display_pipe_funcs->enable callback.371 *372 * Note: Drivers which don't use mipi_dbi_pipe_update() because they have custom373 * framebuffer flushing, can't use this function since they both use the same374 * flushing code.375 */376void mipi_dbi_enable_flush(struct mipi_dbi_dev *dbidev,377			   struct drm_crtc_state *crtc_state,378			   struct drm_plane_state *plane_state)379{380	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);381	struct drm_framebuffer *fb = plane_state->fb;382	struct drm_rect rect = {383		.x1 = 0,384		.x2 = fb->width,385		.y1 = 0,386		.y2 = fb->height,387	};388	int idx;389 390	if (!drm_dev_enter(&dbidev->drm, &idx))391		return;392 393	mipi_dbi_fb_dirty(&shadow_plane_state->data[0], fb, &rect,394			  &shadow_plane_state->fmtcnv_state);395	backlight_enable(dbidev->backlight);396 397	drm_dev_exit(idx);398}399EXPORT_SYMBOL(mipi_dbi_enable_flush);400 401static void mipi_dbi_blank(struct mipi_dbi_dev *dbidev)402{403	struct drm_device *drm = &dbidev->drm;404	u16 height = drm->mode_config.min_height;405	u16 width = drm->mode_config.min_width;406	struct mipi_dbi *dbi = &dbidev->dbi;407	size_t len = width * height * 2;408	int idx;409 410	if (!drm_dev_enter(drm, &idx))411		return;412 413	memset(dbidev->tx_buf, 0, len);414 415	mipi_dbi_set_window_address(dbidev, 0, width - 1, 0, height - 1);416	mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START,417			     (u8 *)dbidev->tx_buf, len);418 419	drm_dev_exit(idx);420}421 422/**423 * mipi_dbi_pipe_disable - MIPI DBI pipe disable helper424 * @pipe: Display pipe425 *426 * This function disables backlight if present, if not the display memory is427 * blanked. The regulator is disabled if in use. Drivers can use this as their428 * &drm_simple_display_pipe_funcs->disable callback.429 */430void mipi_dbi_pipe_disable(struct drm_simple_display_pipe *pipe)431{432	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);433 434	DRM_DEBUG_KMS("\n");435 436	if (dbidev->backlight)437		backlight_disable(dbidev->backlight);438	else439		mipi_dbi_blank(dbidev);440 441	if (dbidev->regulator)442		regulator_disable(dbidev->regulator);443	if (dbidev->io_regulator)444		regulator_disable(dbidev->io_regulator);445}446EXPORT_SYMBOL(mipi_dbi_pipe_disable);447 448/**449 * mipi_dbi_pipe_begin_fb_access - MIPI DBI pipe begin-access helper450 * @pipe: Display pipe451 * @plane_state: Plane state452 *453 * This function implements struct &drm_simple_display_funcs.begin_fb_access.454 *455 * See drm_gem_begin_shadow_fb_access() for details and mipi_dbi_pipe_cleanup_fb()456 * for cleanup.457 *458 * Returns:459 * 0 on success, or a negative errno code otherwise.460 */461int mipi_dbi_pipe_begin_fb_access(struct drm_simple_display_pipe *pipe,462				  struct drm_plane_state *plane_state)463{464	return drm_gem_begin_shadow_fb_access(&pipe->plane, plane_state);465}466EXPORT_SYMBOL(mipi_dbi_pipe_begin_fb_access);467 468/**469 * mipi_dbi_pipe_end_fb_access - MIPI DBI pipe end-access helper470 * @pipe: Display pipe471 * @plane_state: Plane state472 *473 * This function implements struct &drm_simple_display_funcs.end_fb_access.474 *475 * See mipi_dbi_pipe_begin_fb_access().476 */477void mipi_dbi_pipe_end_fb_access(struct drm_simple_display_pipe *pipe,478				 struct drm_plane_state *plane_state)479{480	drm_gem_end_shadow_fb_access(&pipe->plane, plane_state);481}482EXPORT_SYMBOL(mipi_dbi_pipe_end_fb_access);483 484/**485 * mipi_dbi_pipe_reset_plane - MIPI DBI plane-reset helper486 * @pipe: Display pipe487 *488 * This function implements struct &drm_simple_display_funcs.reset_plane489 * for MIPI DBI planes.490 */491void mipi_dbi_pipe_reset_plane(struct drm_simple_display_pipe *pipe)492{493	drm_gem_reset_shadow_plane(&pipe->plane);494}495EXPORT_SYMBOL(mipi_dbi_pipe_reset_plane);496 497/**498 * mipi_dbi_pipe_duplicate_plane_state - duplicates MIPI DBI plane state499 * @pipe: Display pipe500 *501 * This function implements struct &drm_simple_display_funcs.duplicate_plane_state502 * for MIPI DBI planes.503 *504 * See drm_gem_duplicate_shadow_plane_state() for additional details.505 *506 * Returns:507 * A pointer to a new plane state on success, or NULL otherwise.508 */509struct drm_plane_state *mipi_dbi_pipe_duplicate_plane_state(struct drm_simple_display_pipe *pipe)510{511	return drm_gem_duplicate_shadow_plane_state(&pipe->plane);512}513EXPORT_SYMBOL(mipi_dbi_pipe_duplicate_plane_state);514 515/**516 * mipi_dbi_pipe_destroy_plane_state - cleans up MIPI DBI plane state517 * @pipe: Display pipe518 * @plane_state: Plane state519 *520 * This function implements struct drm_simple_display_funcs.destroy_plane_state521 * for MIPI DBI planes.522 *523 * See drm_gem_destroy_shadow_plane_state() for additional details.524 */525void mipi_dbi_pipe_destroy_plane_state(struct drm_simple_display_pipe *pipe,526				       struct drm_plane_state *plane_state)527{528	drm_gem_destroy_shadow_plane_state(&pipe->plane, plane_state);529}530EXPORT_SYMBOL(mipi_dbi_pipe_destroy_plane_state);531 532static int mipi_dbi_connector_get_modes(struct drm_connector *connector)533{534	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(connector->dev);535 536	return drm_connector_helper_get_modes_fixed(connector, &dbidev->mode);537}538 539static const struct drm_connector_helper_funcs mipi_dbi_connector_hfuncs = {540	.get_modes = mipi_dbi_connector_get_modes,541};542 543static const struct drm_connector_funcs mipi_dbi_connector_funcs = {544	.reset = drm_atomic_helper_connector_reset,545	.fill_modes = drm_helper_probe_single_connector_modes,546	.destroy = drm_connector_cleanup,547	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,548	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,549};550 551static int mipi_dbi_rotate_mode(struct drm_display_mode *mode,552				unsigned int rotation)553{554	if (rotation == 0 || rotation == 180) {555		return 0;556	} else if (rotation == 90 || rotation == 270) {557		swap(mode->hdisplay, mode->vdisplay);558		swap(mode->hsync_start, mode->vsync_start);559		swap(mode->hsync_end, mode->vsync_end);560		swap(mode->htotal, mode->vtotal);561		swap(mode->width_mm, mode->height_mm);562		return 0;563	} else {564		return -EINVAL;565	}566}567 568static const struct drm_mode_config_funcs mipi_dbi_mode_config_funcs = {569	.fb_create = drm_gem_fb_create_with_dirty,570	.atomic_check = drm_atomic_helper_check,571	.atomic_commit = drm_atomic_helper_commit,572};573 574static const uint32_t mipi_dbi_formats[] = {575	DRM_FORMAT_RGB565,576	DRM_FORMAT_XRGB8888,577};578 579/**580 * mipi_dbi_dev_init_with_formats - MIPI DBI device initialization with custom formats581 * @dbidev: MIPI DBI device structure to initialize582 * @funcs: Display pipe functions583 * @formats: Array of supported formats (DRM_FORMAT\_\*).584 * @format_count: Number of elements in @formats585 * @mode: Display mode586 * @rotation: Initial rotation in degrees Counter Clock Wise587 * @tx_buf_size: Allocate a transmit buffer of this size.588 *589 * This function sets up a &drm_simple_display_pipe with a &drm_connector that590 * has one fixed &drm_display_mode which is rotated according to @rotation.591 * This mode is used to set the mode config min/max width/height properties.592 *593 * Use mipi_dbi_dev_init() if you want native RGB565 and emulated XRGB8888 format.594 *595 * Note:596 * Some of the helper functions expects RGB565 to be the default format and the597 * transmit buffer sized to fit that.598 *599 * Returns:600 * Zero on success, negative error code on failure.601 */602int mipi_dbi_dev_init_with_formats(struct mipi_dbi_dev *dbidev,603				   const struct drm_simple_display_pipe_funcs *funcs,604				   const uint32_t *formats, unsigned int format_count,605				   const struct drm_display_mode *mode,606				   unsigned int rotation, size_t tx_buf_size)607{608	static const uint64_t modifiers[] = {609		DRM_FORMAT_MOD_LINEAR,610		DRM_FORMAT_MOD_INVALID611	};612	struct drm_device *drm = &dbidev->drm;613	int ret;614 615	if (!dbidev->dbi.command)616		return -EINVAL;617 618	ret = drmm_mode_config_init(drm);619	if (ret)620		return ret;621 622	dbidev->tx_buf = devm_kmalloc(drm->dev, tx_buf_size, GFP_KERNEL);623	if (!dbidev->tx_buf)624		return -ENOMEM;625 626	drm_mode_copy(&dbidev->mode, mode);627	ret = mipi_dbi_rotate_mode(&dbidev->mode, rotation);628	if (ret) {629		DRM_ERROR("Illegal rotation value %u\n", rotation);630		return -EINVAL;631	}632 633	drm_connector_helper_add(&dbidev->connector, &mipi_dbi_connector_hfuncs);634	ret = drm_connector_init(drm, &dbidev->connector, &mipi_dbi_connector_funcs,635				 DRM_MODE_CONNECTOR_SPI);636	if (ret)637		return ret;638 639	ret = drm_simple_display_pipe_init(drm, &dbidev->pipe, funcs, formats, format_count,640					   modifiers, &dbidev->connector);641	if (ret)642		return ret;643 644	drm_plane_enable_fb_damage_clips(&dbidev->pipe.plane);645 646	drm->mode_config.funcs = &mipi_dbi_mode_config_funcs;647	drm->mode_config.min_width = dbidev->mode.hdisplay;648	drm->mode_config.max_width = dbidev->mode.hdisplay;649	drm->mode_config.min_height = dbidev->mode.vdisplay;650	drm->mode_config.max_height = dbidev->mode.vdisplay;651	dbidev->rotation = rotation;652	dbidev->pixel_format = formats[0];653	if (formats[0] == DRM_FORMAT_RGB888)654		dbidev->dbi.write_memory_bpw = 8;655 656	DRM_DEBUG_KMS("rotation = %u\n", rotation);657 658	return 0;659}660EXPORT_SYMBOL(mipi_dbi_dev_init_with_formats);661 662/**663 * mipi_dbi_dev_init - MIPI DBI device initialization664 * @dbidev: MIPI DBI device structure to initialize665 * @funcs: Display pipe functions666 * @mode: Display mode667 * @rotation: Initial rotation in degrees Counter Clock Wise668 *669 * This function sets up a &drm_simple_display_pipe with a &drm_connector that670 * has one fixed &drm_display_mode which is rotated according to @rotation.671 * This mode is used to set the mode config min/max width/height properties.672 * Additionally &mipi_dbi.tx_buf is allocated.673 *674 * Supported formats: Native RGB565 and emulated XRGB8888.675 *676 * Returns:677 * Zero on success, negative error code on failure.678 */679int mipi_dbi_dev_init(struct mipi_dbi_dev *dbidev,680		      const struct drm_simple_display_pipe_funcs *funcs,681		      const struct drm_display_mode *mode, unsigned int rotation)682{683	size_t bufsize = mode->vdisplay * mode->hdisplay * sizeof(u16);684 685	dbidev->drm.mode_config.preferred_depth = 16;686 687	return mipi_dbi_dev_init_with_formats(dbidev, funcs, mipi_dbi_formats,688					      ARRAY_SIZE(mipi_dbi_formats), mode,689					      rotation, bufsize);690}691EXPORT_SYMBOL(mipi_dbi_dev_init);692 693/**694 * mipi_dbi_hw_reset - Hardware reset of controller695 * @dbi: MIPI DBI structure696 *697 * Reset controller if the &mipi_dbi->reset gpio is set.698 */699void mipi_dbi_hw_reset(struct mipi_dbi *dbi)700{701	if (!dbi->reset)702		return;703 704	gpiod_set_value_cansleep(dbi->reset, 0);705	usleep_range(20, 1000);706	gpiod_set_value_cansleep(dbi->reset, 1);707	msleep(120);708}709EXPORT_SYMBOL(mipi_dbi_hw_reset);710 711/**712 * mipi_dbi_display_is_on - Check if display is on713 * @dbi: MIPI DBI structure714 *715 * This function checks the Power Mode register (if readable) to see if716 * display output is turned on. This can be used to see if the bootloader717 * has already turned on the display avoiding flicker when the pipeline is718 * enabled.719 *720 * Returns:721 * true if the display can be verified to be on, false otherwise.722 */723bool mipi_dbi_display_is_on(struct mipi_dbi *dbi)724{725	u8 val;726 727	if (mipi_dbi_command_read(dbi, MIPI_DCS_GET_POWER_MODE, &val))728		return false;729 730	val &= ~DCS_POWER_MODE_RESERVED_MASK;731 732	/* The poweron/reset value is 08h DCS_POWER_MODE_DISPLAY_NORMAL_MODE */733	if (val != (DCS_POWER_MODE_DISPLAY |734	    DCS_POWER_MODE_DISPLAY_NORMAL_MODE | DCS_POWER_MODE_SLEEP_MODE))735		return false;736 737	DRM_DEBUG_DRIVER("Display is ON\n");738 739	return true;740}741EXPORT_SYMBOL(mipi_dbi_display_is_on);742 743static int mipi_dbi_poweron_reset_conditional(struct mipi_dbi_dev *dbidev, bool cond)744{745	struct device *dev = dbidev->drm.dev;746	struct mipi_dbi *dbi = &dbidev->dbi;747	int ret;748 749	if (dbidev->regulator) {750		ret = regulator_enable(dbidev->regulator);751		if (ret) {752			DRM_DEV_ERROR(dev, "Failed to enable regulator (%d)\n", ret);753			return ret;754		}755	}756 757	if (dbidev->io_regulator) {758		ret = regulator_enable(dbidev->io_regulator);759		if (ret) {760			DRM_DEV_ERROR(dev, "Failed to enable I/O regulator (%d)\n", ret);761			if (dbidev->regulator)762				regulator_disable(dbidev->regulator);763			return ret;764		}765	}766 767	if (cond && mipi_dbi_display_is_on(dbi))768		return 1;769 770	mipi_dbi_hw_reset(dbi);771	ret = mipi_dbi_command(dbi, MIPI_DCS_SOFT_RESET);772	if (ret) {773		DRM_DEV_ERROR(dev, "Failed to send reset command (%d)\n", ret);774		if (dbidev->regulator)775			regulator_disable(dbidev->regulator);776		if (dbidev->io_regulator)777			regulator_disable(dbidev->io_regulator);778		return ret;779	}780 781	/*782	 * If we did a hw reset, we know the controller is in Sleep mode and783	 * per MIPI DSC spec should wait 5ms after soft reset. If we didn't,784	 * we assume worst case and wait 120ms.785	 */786	if (dbi->reset)787		usleep_range(5000, 20000);788	else789		msleep(120);790 791	return 0;792}793 794/**795 * mipi_dbi_poweron_reset - MIPI DBI poweron and reset796 * @dbidev: MIPI DBI device structure797 *798 * This function enables the regulator if used and does a hardware and software799 * reset.800 *801 * Returns:802 * Zero on success, or a negative error code.803 */804int mipi_dbi_poweron_reset(struct mipi_dbi_dev *dbidev)805{806	return mipi_dbi_poweron_reset_conditional(dbidev, false);807}808EXPORT_SYMBOL(mipi_dbi_poweron_reset);809 810/**811 * mipi_dbi_poweron_conditional_reset - MIPI DBI poweron and conditional reset812 * @dbidev: MIPI DBI device structure813 *814 * This function enables the regulator if used and if the display is off, it815 * does a hardware and software reset. If mipi_dbi_display_is_on() determines816 * that the display is on, no reset is performed.817 *818 * Returns:819 * Zero if the controller was reset, 1 if the display was already on, or a820 * negative error code.821 */822int mipi_dbi_poweron_conditional_reset(struct mipi_dbi_dev *dbidev)823{824	return mipi_dbi_poweron_reset_conditional(dbidev, true);825}826EXPORT_SYMBOL(mipi_dbi_poweron_conditional_reset);827 828#if IS_ENABLED(CONFIG_SPI)829 830/**831 * mipi_dbi_spi_cmd_max_speed - get the maximum SPI bus speed832 * @spi: SPI device833 * @len: The transfer buffer length.834 *835 * Many controllers have a max speed of 10MHz, but can be pushed way beyond836 * that. Increase reliability by running pixel data at max speed and the rest837 * at 10MHz, preventing transfer glitches from messing up the init settings.838 */839u32 mipi_dbi_spi_cmd_max_speed(struct spi_device *spi, size_t len)840{841	if (len > 64)842		return 0; /* use default */843 844	return min_t(u32, 10000000, spi->max_speed_hz);845}846EXPORT_SYMBOL(mipi_dbi_spi_cmd_max_speed);847 848/*849 * MIPI DBI Type C Option 1850 *851 * If the SPI controller doesn't have 9 bits per word support,852 * use blocks of 9 bytes to send 8x 9-bit words using a 8-bit SPI transfer.853 * Pad partial blocks with MIPI_DCS_NOP (zero).854 * This is how the D/C bit (x) is added:855 *     x7654321856 *     0x765432857 *     10x76543858 *     210x7654859 *     3210x765860 *     43210x76861 *     543210x7862 *     6543210x863 *     76543210864 */865 866static int mipi_dbi_spi1e_transfer(struct mipi_dbi *dbi, int dc,867				   const void *buf, size_t len,868				   unsigned int bpw)869{870	bool swap_bytes = (bpw == 16);871	size_t chunk, max_chunk = dbi->tx_buf9_len;872	struct spi_device *spi = dbi->spi;873	struct spi_transfer tr = {874		.tx_buf = dbi->tx_buf9,875		.bits_per_word = 8,876	};877	struct spi_message m;878	const u8 *src = buf;879	int i, ret;880	u8 *dst;881 882	if (drm_debug_enabled(DRM_UT_DRIVER))883		pr_debug("[drm:%s] dc=%d, max_chunk=%zu, transfers:\n",884			 __func__, dc, max_chunk);885 886	tr.speed_hz = mipi_dbi_spi_cmd_max_speed(spi, len);887	spi_message_init_with_transfers(&m, &tr, 1);888 889	if (!dc) {890		if (WARN_ON_ONCE(len != 1))891			return -EINVAL;892 893		/* Command: pad no-op's (zeroes) at beginning of block */894		dst = dbi->tx_buf9;895		memset(dst, 0, 9);896		dst[8] = *src;897		tr.len = 9;898 899		return spi_sync(spi, &m);900	}901 902	/* max with room for adding one bit per byte */903	max_chunk = max_chunk / 9 * 8;904	/* but no bigger than len */905	max_chunk = min(max_chunk, len);906	/* 8 byte blocks */907	max_chunk = max_t(size_t, 8, max_chunk & ~0x7);908 909	while (len) {910		size_t added = 0;911 912		chunk = min(len, max_chunk);913		len -= chunk;914		dst = dbi->tx_buf9;915 916		if (chunk < 8) {917			u8 val, carry = 0;918 919			/* Data: pad no-op's (zeroes) at end of block */920			memset(dst, 0, 9);921 922			if (swap_bytes) {923				for (i = 1; i < (chunk + 1); i++) {924					val = src[1];925					*dst++ = carry | BIT(8 - i) | (val >> i);926					carry = val << (8 - i);927					i++;928					val = src[0];929					*dst++ = carry | BIT(8 - i) | (val >> i);930					carry = val << (8 - i);931					src += 2;932				}933				*dst++ = carry;934			} else {935				for (i = 1; i < (chunk + 1); i++) {936					val = *src++;937					*dst++ = carry | BIT(8 - i) | (val >> i);938					carry = val << (8 - i);939				}940				*dst++ = carry;941			}942 943			chunk = 8;944			added = 1;945		} else {946			for (i = 0; i < chunk; i += 8) {947				if (swap_bytes) {948					*dst++ =                 BIT(7) | (src[1] >> 1);949					*dst++ = (src[1] << 7) | BIT(6) | (src[0] >> 2);950					*dst++ = (src[0] << 6) | BIT(5) | (src[3] >> 3);951					*dst++ = (src[3] << 5) | BIT(4) | (src[2] >> 4);952					*dst++ = (src[2] << 4) | BIT(3) | (src[5] >> 5);953					*dst++ = (src[5] << 3) | BIT(2) | (src[4] >> 6);954					*dst++ = (src[4] << 2) | BIT(1) | (src[7] >> 7);955					*dst++ = (src[7] << 1) | BIT(0);956					*dst++ = src[6];957				} else {958					*dst++ =                 BIT(7) | (src[0] >> 1);959					*dst++ = (src[0] << 7) | BIT(6) | (src[1] >> 2);960					*dst++ = (src[1] << 6) | BIT(5) | (src[2] >> 3);961					*dst++ = (src[2] << 5) | BIT(4) | (src[3] >> 4);962					*dst++ = (src[3] << 4) | BIT(3) | (src[4] >> 5);963					*dst++ = (src[4] << 3) | BIT(2) | (src[5] >> 6);964					*dst++ = (src[5] << 2) | BIT(1) | (src[6] >> 7);965					*dst++ = (src[6] << 1) | BIT(0);966					*dst++ = src[7];967				}968 969				src += 8;970				added++;971			}972		}973 974		tr.len = chunk + added;975 976		ret = spi_sync(spi, &m);977		if (ret)978			return ret;979	}980 981	return 0;982}983 984static int mipi_dbi_spi1_transfer(struct mipi_dbi *dbi, int dc,985				  const void *buf, size_t len,986				  unsigned int bpw)987{988	struct spi_device *spi = dbi->spi;989	struct spi_transfer tr = {990		.bits_per_word = 9,991	};992	const u16 *src16 = buf;993	const u8 *src8 = buf;994	struct spi_message m;995	size_t max_chunk;996	u16 *dst16;997	int ret;998 999	if (!spi_is_bpw_supported(spi, 9))1000		return mipi_dbi_spi1e_transfer(dbi, dc, buf, len, bpw);1001 1002	tr.speed_hz = mipi_dbi_spi_cmd_max_speed(spi, len);1003	max_chunk = dbi->tx_buf9_len;1004	dst16 = dbi->tx_buf9;1005 1006	if (drm_debug_enabled(DRM_UT_DRIVER))1007		pr_debug("[drm:%s] dc=%d, max_chunk=%zu, transfers:\n",1008			 __func__, dc, max_chunk);1009 1010	max_chunk = min(max_chunk / 2, len);1011 1012	spi_message_init_with_transfers(&m, &tr, 1);1013	tr.tx_buf = dst16;1014 1015	while (len) {1016		size_t chunk = min(len, max_chunk);1017		unsigned int i;1018 1019		if (bpw == 16) {1020			for (i = 0; i < (chunk * 2); i += 2) {1021				dst16[i]     = *src16 >> 8;1022				dst16[i + 1] = *src16++ & 0xFF;1023				if (dc) {1024					dst16[i]     |= 0x0100;1025					dst16[i + 1] |= 0x0100;1026				}1027			}1028		} else {1029			for (i = 0; i < chunk; i++) {1030				dst16[i] = *src8++;1031				if (dc)1032					dst16[i] |= 0x0100;1033			}1034		}1035 1036		tr.len = chunk * 2;1037		len -= chunk;1038 1039		ret = spi_sync(spi, &m);1040		if (ret)1041			return ret;1042	}1043 1044	return 0;1045}1046 1047static int mipi_dbi_typec1_command_read(struct mipi_dbi *dbi, u8 *cmd,1048					u8 *data, size_t len)1049{1050	struct spi_device *spi = dbi->spi;1051	u32 speed_hz = min_t(u32, MIPI_DBI_MAX_SPI_READ_SPEED,1052			     spi->max_speed_hz / 2);1053	struct spi_transfer tr[2] = {1054		{1055			.speed_hz = speed_hz,1056			.bits_per_word = 9,1057			.tx_buf = dbi->tx_buf9,1058			.len = 2,1059		}, {1060			.speed_hz = speed_hz,1061			.bits_per_word = 8,1062			.len = len,1063			.rx_buf = data,1064		},1065	};1066	struct spi_message m;1067	u16 *dst16;1068	int ret;1069 1070	if (!len)1071		return -EINVAL;1072 1073	if (!spi_is_bpw_supported(spi, 9)) {1074		/*1075		 * FIXME: implement something like mipi_dbi_spi1e_transfer() but1076		 * for reads using emulation.1077		 */1078		dev_err(&spi->dev,1079			"reading on host not supporting 9 bpw not yet implemented\n");1080		return -EOPNOTSUPP;1081	}1082 1083	/*1084	 * Turn the 8bit command into a 16bit version of the command in the1085	 * buffer. Only 9 bits of this will be used when executing the actual1086	 * transfer.1087	 */1088	dst16 = dbi->tx_buf9;1089	dst16[0] = *cmd;1090 1091	spi_message_init_with_transfers(&m, tr, ARRAY_SIZE(tr));1092	ret = spi_sync(spi, &m);1093 1094	if (!ret)1095		MIPI_DBI_DEBUG_COMMAND(*cmd, data, len);1096 1097	return ret;1098}1099 1100static int mipi_dbi_typec1_command(struct mipi_dbi *dbi, u8 *cmd,1101				   u8 *parameters, size_t num)1102{1103	unsigned int bpw = 8;1104	int ret;1105 1106	if (mipi_dbi_command_is_read(dbi, *cmd))1107		return mipi_dbi_typec1_command_read(dbi, cmd, parameters, num);1108 1109	MIPI_DBI_DEBUG_COMMAND(*cmd, parameters, num);1110 1111	ret = mipi_dbi_spi1_transfer(dbi, 0, cmd, 1, 8);1112	if (ret || !num)1113		return ret;1114 1115	if (*cmd == MIPI_DCS_WRITE_MEMORY_START)1116		bpw = dbi->write_memory_bpw;1117 1118	return mipi_dbi_spi1_transfer(dbi, 1, parameters, num, bpw);1119}1120 1121/* MIPI DBI Type C Option 3 */1122 1123static int mipi_dbi_typec3_command_read(struct mipi_dbi *dbi, u8 *cmd,1124					u8 *data, size_t len)1125{1126	struct spi_device *spi = dbi->spi;1127	u32 speed_hz = min_t(u32, MIPI_DBI_MAX_SPI_READ_SPEED,1128			     spi->max_speed_hz / 2);1129	struct spi_transfer tr[2] = {1130		{1131			.speed_hz = speed_hz,1132			.tx_buf = cmd,1133			.len = 1,1134		}, {1135			.speed_hz = speed_hz,1136			.len = len,1137		},1138	};1139	struct spi_message m;1140	u8 *buf;1141	int ret;1142 1143	if (!len)1144		return -EINVAL;1145 1146	/*1147	 * Support non-standard 24-bit and 32-bit Nokia read commands which1148	 * start with a dummy clock, so we need to read an extra byte.1149	 */1150	if (*cmd == MIPI_DCS_GET_DISPLAY_ID ||1151	    *cmd == MIPI_DCS_GET_DISPLAY_STATUS) {1152		if (!(len == 3 || len == 4))1153			return -EINVAL;1154 1155		tr[1].len = len + 1;1156	}1157 1158	buf = kmalloc(tr[1].len, GFP_KERNEL);1159	if (!buf)1160		return -ENOMEM;1161 1162	tr[1].rx_buf = buf;1163 1164	spi_bus_lock(spi->controller);1165	gpiod_set_value_cansleep(dbi->dc, 0);1166 1167	spi_message_init_with_transfers(&m, tr, ARRAY_SIZE(tr));1168	ret = spi_sync_locked(spi, &m);1169	spi_bus_unlock(spi->controller);1170	if (ret)1171		goto err_free;1172 1173	if (tr[1].len == len) {1174		memcpy(data, buf, len);1175	} else {1176		unsigned int i;1177 1178		for (i = 0; i < len; i++)1179			data[i] = (buf[i] << 1) | (buf[i + 1] >> 7);1180	}1181 1182	MIPI_DBI_DEBUG_COMMAND(*cmd, data, len);1183 1184err_free:1185	kfree(buf);1186 1187	return ret;1188}1189 1190static int mipi_dbi_typec3_command(struct mipi_dbi *dbi, u8 *cmd,1191				   u8 *par, size_t num)1192{1193	struct spi_device *spi = dbi->spi;1194	unsigned int bpw = 8;1195	u32 speed_hz;1196	int ret;1197 1198	if (mipi_dbi_command_is_read(dbi, *cmd))1199		return mipi_dbi_typec3_command_read(dbi, cmd, par, num);1200 1201	MIPI_DBI_DEBUG_COMMAND(*cmd, par, num);1202 1203	spi_bus_lock(spi->controller);1204	gpiod_set_value_cansleep(dbi->dc, 0);1205	speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 1);1206	ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, cmd, 1);1207	spi_bus_unlock(spi->controller);1208	if (ret || !num)1209		return ret;1210 1211	if (*cmd == MIPI_DCS_WRITE_MEMORY_START)1212		bpw = dbi->write_memory_bpw;1213 1214	spi_bus_lock(spi->controller);1215	gpiod_set_value_cansleep(dbi->dc, 1);1216	speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);1217	ret = mipi_dbi_spi_transfer(spi, speed_hz, bpw, par, num);1218	spi_bus_unlock(spi->controller);1219 1220	return ret;1221}1222 1223/**1224 * mipi_dbi_spi_init - Initialize MIPI DBI SPI interface1225 * @spi: SPI device1226 * @dbi: MIPI DBI structure to initialize1227 * @dc: D/C gpio (optional)1228 *1229 * This function sets &mipi_dbi->command, enables &mipi_dbi->read_commands for the1230 * usual read commands. It should be followed by a call to mipi_dbi_dev_init() or1231 * a driver-specific init.1232 *1233 * If @dc is set, a Type C Option 3 interface is assumed, if not1234 * Type C Option 1.1235 *1236 * If the command is %MIPI_DCS_WRITE_MEMORY_START and the pixel format is RGB565, endianness has1237 * to be taken into account. The MIPI DBI serial interface is big endian and framebuffers are1238 * assumed stored in memory as little endian (%DRM_FORMAT_BIG_ENDIAN is not supported).1239 *1240 * This is how endianness is handled:1241 *1242 * Option 1 (D/C as a bit): The buffer is sent on the wire byte by byte so the 16-bit buffer is1243 *                          byteswapped before transfer.1244 *1245 * Option 3 (D/C as a gpio): If the SPI controller supports 16 bits per word the buffer can be1246 *                           sent as-is. If not the caller is responsible for swapping the bytes1247 *                           before calling mipi_dbi_command_buf() and the buffer is sent 8 bpw.1248 *1249 * This handling is optimised for %DRM_FORMAT_RGB565 framebuffers.1250 *1251 * If the interface is Option 1 and the SPI controller doesn't support 9 bits per word,1252 * the buffer is sent as 9x 8-bit words, padded with MIPI DCS no-op commands if necessary.1253 *1254 * Returns:1255 * Zero on success, negative error code on failure.1256 */1257int mipi_dbi_spi_init(struct spi_device *spi, struct mipi_dbi *dbi,1258		      struct gpio_desc *dc)1259{1260	struct device *dev = &spi->dev;1261	int ret;1262 1263	/*1264	 * Even though it's not the SPI device that does DMA (the master does),1265	 * the dma mask is necessary for the dma_alloc_wc() in the GEM code1266	 * (e.g., drm_gem_dma_create()). The dma_addr returned will be a physical1267	 * address which might be different from the bus address, but this is1268	 * not a problem since the address will not be used.1269	 * The virtual address is used in the transfer and the SPI core1270	 * re-maps it on the SPI master device using the DMA streaming API1271	 * (spi_map_buf()).1272	 */1273	if (!dev->coherent_dma_mask) {1274		ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));1275		if (ret) {1276			dev_warn(dev, "Failed to set dma mask %d\n", ret);1277			return ret;1278		}1279	}1280 1281	dbi->spi = spi;1282	dbi->read_commands = mipi_dbi_dcs_read_commands;1283	dbi->write_memory_bpw = 16;1284 1285	if (dc) {1286		dbi->command = mipi_dbi_typec3_command;1287		dbi->dc = dc;1288		if (!spi_is_bpw_supported(spi, 16)) {1289			dbi->write_memory_bpw = 8;1290			dbi->swap_bytes = true;1291		}1292	} else {1293		dbi->command = mipi_dbi_typec1_command;1294		dbi->tx_buf9_len = SZ_16K;1295		dbi->tx_buf9 = devm_kmalloc(dev, dbi->tx_buf9_len, GFP_KERNEL);1296		if (!dbi->tx_buf9)1297			return -ENOMEM;1298	}1299 1300	mutex_init(&dbi->cmdlock);1301 1302	DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000);1303 1304	return 0;1305}1306EXPORT_SYMBOL(mipi_dbi_spi_init);1307 1308/**1309 * mipi_dbi_spi_transfer - SPI transfer helper1310 * @spi: SPI device1311 * @speed_hz: Override speed (optional)1312 * @bpw: Bits per word1313 * @buf: Buffer to transfer1314 * @len: Buffer length1315 *1316 * This SPI transfer helper breaks up the transfer of @buf into chunks which1317 * the SPI controller driver can handle. The SPI bus must be locked when1318 * calling this.1319 *1320 * Returns:1321 * Zero on success, negative error code on failure.1322 */1323int mipi_dbi_spi_transfer(struct spi_device *spi, u32 speed_hz,1324			  u8 bpw, const void *buf, size_t len)1325{1326	size_t max_chunk = spi_max_transfer_size(spi);1327	struct spi_transfer tr = {1328		.bits_per_word = bpw,1329		.speed_hz = speed_hz,1330	};1331	struct spi_message m;1332	size_t chunk;1333	int ret;1334 1335	/* In __spi_validate, there's a validation that no partial transfers1336	 * are accepted (xfer->len % w_size must be zero).1337	 * Here we align max_chunk to multiple of 2 (16bits),1338	 * to prevent transfers from being rejected.1339	 */1340	max_chunk = ALIGN_DOWN(max_chunk, 2);1341 1342	spi_message_init_with_transfers(&m, &tr, 1);1343 1344	while (len) {1345		chunk = min(len, max_chunk);1346 1347		tr.tx_buf = buf;1348		tr.len = chunk;1349		buf += chunk;1350		len -= chunk;1351 1352		ret = spi_sync_locked(spi, &m);1353		if (ret)1354			return ret;1355	}1356 1357	return 0;1358}1359EXPORT_SYMBOL(mipi_dbi_spi_transfer);1360 1361#endif /* CONFIG_SPI */1362 1363#ifdef CONFIG_DEBUG_FS1364 1365static ssize_t mipi_dbi_debugfs_command_write(struct file *file,1366					      const char __user *ubuf,1367					      size_t count, loff_t *ppos)1368{1369	struct seq_file *m = file->private_data;1370	struct mipi_dbi_dev *dbidev = m->private;1371	u8 val, cmd = 0, parameters[64];1372	char *buf, *pos, *token;1373	int i, ret, idx;1374 1375	if (!drm_dev_enter(&dbidev->drm, &idx))1376		return -ENODEV;1377 1378	buf = memdup_user_nul(ubuf, count);1379	if (IS_ERR(buf)) {1380		ret = PTR_ERR(buf);1381		goto err_exit;1382	}1383 1384	/* strip trailing whitespace */1385	for (i = count - 1; i > 0; i--)1386		if (isspace(buf[i]))1387			buf[i] = '\0';1388		else1389			break;1390	i = 0;1391	pos = buf;1392	while (pos) {1393		token = strsep(&pos, " ");1394		if (!token) {1395			ret = -EINVAL;1396			goto err_free;1397		}1398 1399		ret = kstrtou8(token, 16, &val);1400		if (ret < 0)1401			goto err_free;1402 1403		if (token == buf)1404			cmd = val;1405		else1406			parameters[i++] = val;1407 1408		if (i == 64) {1409			ret = -E2BIG;1410			goto err_free;1411		}1412	}1413 1414	ret = mipi_dbi_command_buf(&dbidev->dbi, cmd, parameters, i);1415 1416err_free:1417	kfree(buf);1418err_exit:1419	drm_dev_exit(idx);1420 1421	return ret < 0 ? ret : count;1422}1423 1424static int mipi_dbi_debugfs_command_show(struct seq_file *m, void *unused)1425{1426	struct mipi_dbi_dev *dbidev = m->private;1427	struct mipi_dbi *dbi = &dbidev->dbi;1428	u8 cmd, val[4];1429	int ret, idx;1430	size_t len;1431 1432	if (!drm_dev_enter(&dbidev->drm, &idx))1433		return -ENODEV;1434 1435	for (cmd = 0; cmd < 255; cmd++) {1436		if (!mipi_dbi_command_is_read(dbi, cmd))1437			continue;1438 1439		switch (cmd) {1440		case MIPI_DCS_READ_MEMORY_START:1441		case MIPI_DCS_READ_MEMORY_CONTINUE:1442			len = 2;1443			break;1444		case MIPI_DCS_GET_DISPLAY_ID:1445			len = 3;1446			break;1447		case MIPI_DCS_GET_DISPLAY_STATUS:1448			len = 4;1449			break;1450		default:1451			len = 1;1452			break;1453		}1454 1455		seq_printf(m, "%02x: ", cmd);1456		ret = mipi_dbi_command_buf(dbi, cmd, val, len);1457		if (ret) {1458			seq_puts(m, "XX\n");1459			continue;1460		}1461		seq_printf(m, "%*phN\n", (int)len, val);1462	}1463 1464	drm_dev_exit(idx);1465 1466	return 0;1467}1468 1469static int mipi_dbi_debugfs_command_open(struct inode *inode,1470					 struct file *file)1471{1472	return single_open(file, mipi_dbi_debugfs_command_show,1473			   inode->i_private);1474}1475 1476static const struct file_operations mipi_dbi_debugfs_command_fops = {1477	.owner = THIS_MODULE,1478	.open = mipi_dbi_debugfs_command_open,1479	.read = seq_read,1480	.llseek = seq_lseek,1481	.release = single_release,1482	.write = mipi_dbi_debugfs_command_write,1483};1484 1485/**1486 * mipi_dbi_debugfs_init - Create debugfs entries1487 * @minor: DRM minor1488 *1489 * This function creates a 'command' debugfs file for sending commands to the1490 * controller or getting the read command values.1491 * Drivers can use this as their &drm_driver->debugfs_init callback.1492 *1493 */1494void mipi_dbi_debugfs_init(struct drm_minor *minor)1495{1496	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(minor->dev);1497	umode_t mode = S_IFREG | S_IWUSR;1498 1499	if (dbidev->dbi.read_commands)1500		mode |= S_IRUGO;1501	debugfs_create_file("command", mode, minor->debugfs_root, dbidev,1502			    &mipi_dbi_debugfs_command_fops);1503}1504EXPORT_SYMBOL(mipi_dbi_debugfs_init);1505 1506#endif1507 1508MODULE_DESCRIPTION("MIPI Display Bus Interface (DBI) LCD controller support");1509MODULE_LICENSE("GPL");1510