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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * MIPI Display Bus Interface (DBI) LCD controller support
4 *
5 * Copyright 2016 Noralf Trønnes
6 */
7
8#include <linux/debugfs.h>
9#include <linux/delay.h>
10#include <linux/dma-buf.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_gem_cma_helper.h>
20#include <drm/drm_format_helper.h>
21#include <drm/drm_fourcc.h>
22#include <drm/drm_gem_framebuffer_helper.h>
23#include <drm/drm_mipi_dbi.h>
24#include <drm/drm_modes.h>
25#include <drm/drm_probe_helper.h>
26#include <drm/drm_rect.h>
27#include <drm/drm_vblank.h>
28#include <video/mipi_display.h>
29
30#define MIPI_DBI_MAX_SPI_READ_SPEED 2000000 /* 2MHz */
31
32#define DCS_POWER_MODE_DISPLAY BIT(2)
33#define DCS_POWER_MODE_DISPLAY_NORMAL_MODE BIT(3)
34#define DCS_POWER_MODE_SLEEP_MODE BIT(4)
35#define DCS_POWER_MODE_PARTIAL_MODE BIT(5)
36#define DCS_POWER_MODE_IDLE_MODE BIT(6)
37#define DCS_POWER_MODE_RESERVED_MASK (BIT(0) | BIT(1) | BIT(7))
38
39/**
40 * DOC: overview
41 *
42 * This library provides helpers for MIPI Display Bus Interface (DBI)
43 * compatible display controllers.
44 *
45 * Many controllers for tiny lcd displays are MIPI compliant and can use this
46 * library. If a controller uses registers 0x2A and 0x2B to set the area to
47 * update and uses register 0x2C to write to frame memory, it is most likely
48 * MIPI compliant.
49 *
50 * Only MIPI Type 1 displays are supported since a full frame memory is needed.
51 *
52 * There are 3 MIPI DBI implementation types:
53 *
54 * A. Motorola 6800 type parallel bus
55 *
56 * B. Intel 8080 type parallel bus
57 *
58 * C. SPI type with 3 options:
59 *
60 * 1. 9-bit with the Data/Command signal as the ninth bit
61 * 2. Same as above except it's sent as 16 bits
62 * 3. 8-bit with the Data/Command signal as a separate D/CX pin
63 *
64 * Currently mipi_dbi only supports Type C options 1 and 3 with
65 * mipi_dbi_spi_init().
66 */
67
68#define MIPI_DBI_DEBUG_COMMAND(cmd, data, len) \
69({ \
70 if (!len) \
71 DRM_DEBUG_DRIVER("cmd=%02x\n", cmd); \
72 else if (len <= 32) \
73 DRM_DEBUG_DRIVER("cmd=%02x, par=%*ph\n", cmd, (int)len, data);\
74 else \
75 DRM_DEBUG_DRIVER("cmd=%02x, len=%zu\n", cmd, len); \
76})
77
78static const u8 mipi_dbi_dcs_read_commands[] = {
79 MIPI_DCS_GET_DISPLAY_ID,
80 MIPI_DCS_GET_RED_CHANNEL,
81 MIPI_DCS_GET_GREEN_CHANNEL,
82 MIPI_DCS_GET_BLUE_CHANNEL,
83 MIPI_DCS_GET_DISPLAY_STATUS,
84 MIPI_DCS_GET_POWER_MODE,
85 MIPI_DCS_GET_ADDRESS_MODE,
86 MIPI_DCS_GET_PIXEL_FORMAT,
87 MIPI_DCS_GET_DISPLAY_MODE,
88 MIPI_DCS_GET_SIGNAL_MODE,
89 MIPI_DCS_GET_DIAGNOSTIC_RESULT,
90 MIPI_DCS_READ_MEMORY_START,
91 MIPI_DCS_READ_MEMORY_CONTINUE,
92 MIPI_DCS_GET_SCANLINE,
93 MIPI_DCS_GET_DISPLAY_BRIGHTNESS,
94 MIPI_DCS_GET_CONTROL_DISPLAY,
95 MIPI_DCS_GET_POWER_SAVE,
96 MIPI_DCS_GET_CABC_MIN_BRIGHTNESS,
97 MIPI_DCS_READ_DDB_START,
98 MIPI_DCS_READ_DDB_CONTINUE,
99 0, /* sentinel */
100};
101
102static bool mipi_dbi_command_is_read(struct mipi_dbi *dbi, u8 cmd)
103{
104 unsigned int i;
105
106 if (!dbi->read_commands)
107 return false;
108
109 for (i = 0; i < 0xff; i++) {
110 if (!dbi->read_commands[i])
111 return false;
112 if (cmd == dbi->read_commands[i])
113 return true;
114 }
115
116 return false;
117}
118
119/**
120 * mipi_dbi_command_read - MIPI DCS read command
121 * @dbi: MIPI DBI structure
122 * @cmd: Command
123 * @val: Value read
124 *
125 * Send MIPI DCS read command to the controller.
126 *
127 * Returns:
128 * Zero on success, negative error code on failure.
129 */
130int mipi_dbi_command_read(struct mipi_dbi *dbi, u8 cmd, u8 *val)
131{
132 if (!dbi->read_commands)
133 return -EACCES;
134
135 if (!mipi_dbi_command_is_read(dbi, cmd))
136 return -EINVAL;
137
138 return mipi_dbi_command_buf(dbi, cmd, val, 1);
139}
140EXPORT_SYMBOL(mipi_dbi_command_read);
141
142/**
143 * mipi_dbi_command_buf - MIPI DCS command with parameter(s) in an array
144 * @dbi: MIPI DBI structure
145 * @cmd: Command
146 * @data: Parameter buffer
147 * @len: Buffer length
148 *
149 * Returns:
150 * Zero on success, negative error code on failure.
151 */
152int mipi_dbi_command_buf(struct mipi_dbi *dbi, u8 cmd, u8 *data, size_t len)
153{
154 u8 *cmdbuf;
155 int ret;
156
157 /* SPI requires dma-safe buffers */
158 cmdbuf = kmemdup(&cmd, 1, GFP_KERNEL);
159 if (!cmdbuf)
160 return -ENOMEM;
161
162 mutex_lock(&dbi->cmdlock);
163 ret = dbi->command(dbi, cmdbuf, data, len);
164 mutex_unlock(&dbi->cmdlock);
165
166 kfree(cmdbuf);
167
168 return ret;
169}
170EXPORT_SYMBOL(mipi_dbi_command_buf);
171
172/* This should only be used by mipi_dbi_command() */
173int mipi_dbi_command_stackbuf(struct mipi_dbi *dbi, u8 cmd, u8 *data, size_t len)
174{
175 u8 *buf;
176 int ret;
177
178 buf = kmemdup(data, len, GFP_KERNEL);
179 if (!buf)
180 return -ENOMEM;
181
182 ret = mipi_dbi_command_buf(dbi, cmd, buf, len);
183
184 kfree(buf);
185
186 return ret;
187}
188EXPORT_SYMBOL(mipi_dbi_command_stackbuf);
189
190/**
191 * mipi_dbi_buf_copy - Copy a framebuffer, transforming it if necessary
192 * @dst: The destination buffer
193 * @fb: The source framebuffer
194 * @clip: Clipping rectangle of the area to be copied
195 * @swap: When true, swap MSB/LSB of 16-bit values
196 *
197 * Returns:
198 * Zero on success, negative error code on failure.
199 */
200int mipi_dbi_buf_copy(void *dst, struct drm_framebuffer *fb,
201 struct drm_rect *clip, bool swap)
202{
203 struct drm_gem_object *gem = drm_gem_fb_get_obj(fb, 0);
204 struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(gem);
205 struct dma_buf_attachment *import_attach = gem->import_attach;
206 struct drm_format_name_buf format_name;
207 void *src = cma_obj->vaddr;
208 int ret = 0;
209
210 if (import_attach) {
211 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
212 DMA_FROM_DEVICE);
213 if (ret)
214 return ret;
215 }
216
217 switch (fb->format->format) {
218 case DRM_FORMAT_RGB565:
219 if (swap)
220 drm_fb_swab16(dst, src, fb, clip);
221 else
222 drm_fb_memcpy(dst, src, fb, clip);
223 break;
224 case DRM_FORMAT_XRGB8888:
225 drm_fb_xrgb8888_to_rgb565(dst, src, fb, clip, swap);
226 break;
227 default:
228 dev_err_once(fb->dev->dev, "Format is not supported: %s\n",
229 drm_get_format_name(fb->format->format,
230 &format_name));
231 return -EINVAL;
232 }
233
234 if (import_attach)
235 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
236 DMA_FROM_DEVICE);
237 return ret;
238}
239EXPORT_SYMBOL(mipi_dbi_buf_copy);
240
241static void mipi_dbi_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect)
242{
243 struct drm_gem_object *gem = drm_gem_fb_get_obj(fb, 0);
244 struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(gem);
245 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
246 unsigned int height = rect->y2 - rect->y1;
247 unsigned int width = rect->x2 - rect->x1;
248 struct mipi_dbi *dbi = &dbidev->dbi;
249 bool swap = dbi->swap_bytes;
250 int idx, ret = 0;
251 bool full;
252 void *tr;
253
254 if (!dbidev->enabled)
255 return;
256
257 if (!drm_dev_enter(fb->dev, &idx))
258 return;
259
260 full = width == fb->width && height == fb->height;
261
262 DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
263
264 if (!dbi->dc || !full || swap ||
265 fb->format->format == DRM_FORMAT_XRGB8888) {
266 tr = dbidev->tx_buf;
267 ret = mipi_dbi_buf_copy(dbidev->tx_buf, fb, rect, swap);
268 if (ret)
269 goto err_msg;
270 } else {
271 tr = cma_obj->vaddr;
272 }
273
274 mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS,
275 (rect->x1 >> 8) & 0xff, rect->x1 & 0xff,
276 ((rect->x2 - 1) >> 8) & 0xff, (rect->x2 - 1) & 0xff);
277 mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS,
278 (rect->y1 >> 8) & 0xff, rect->y1 & 0xff,
279 ((rect->y2 - 1) >> 8) & 0xff, (rect->y2 - 1) & 0xff);
280
281 ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, tr,
282 width * height * 2);
283err_msg:
284 if (ret)
285 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
286
287 drm_dev_exit(idx);
288}
289
290/**
291 * mipi_dbi_pipe_update - Display pipe update helper
292 * @pipe: Simple display pipe
293 * @old_state: Old plane state
294 *
295 * This function handles framebuffer flushing and vblank events. Drivers can use
296 * this as their &drm_simple_display_pipe_funcs->update callback.
297 */
298void mipi_dbi_pipe_update(struct drm_simple_display_pipe *pipe,
299 struct drm_plane_state *old_state)
300{
301 struct drm_plane_state *state = pipe->plane.state;
302 struct drm_crtc *crtc = &pipe->crtc;
303 struct drm_rect rect;
304
305 if (drm_atomic_helper_damage_merged(old_state, state, &rect))
306 mipi_dbi_fb_dirty(state->fb, &rect);
307
308 if (crtc->state->event) {
309 spin_lock_irq(&crtc->dev->event_lock);
310 drm_crtc_send_vblank_event(crtc, crtc->state->event);
311 spin_unlock_irq(&crtc->dev->event_lock);
312 crtc->state->event = NULL;
313 }
314}
315EXPORT_SYMBOL(mipi_dbi_pipe_update);
316
317/**
318 * mipi_dbi_enable_flush - MIPI DBI enable helper
319 * @dbidev: MIPI DBI device structure
320 * @crtc_state: CRTC state
321 * @plane_state: Plane state
322 *
323 * This function sets &mipi_dbi->enabled, flushes the whole framebuffer and
324 * enables the backlight. Drivers can use this in their
325 * &drm_simple_display_pipe_funcs->enable callback.
326 *
327 * Note: Drivers which don't use mipi_dbi_pipe_update() because they have custom
328 * framebuffer flushing, can't use this function since they both use the same
329 * flushing code.
330 */
331void mipi_dbi_enable_flush(struct mipi_dbi_dev *dbidev,
332 struct drm_crtc_state *crtc_state,
333 struct drm_plane_state *plane_state)
334{
335 struct drm_framebuffer *fb = plane_state->fb;
336 struct drm_rect rect = {
337 .x1 = 0,
338 .x2 = fb->width,
339 .y1 = 0,
340 .y2 = fb->height,
341 };
342 int idx;
343
344 if (!drm_dev_enter(&dbidev->drm, &idx))
345 return;
346
347 dbidev->enabled = true;
348 mipi_dbi_fb_dirty(fb, &rect);
349 backlight_enable(dbidev->backlight);
350
351 drm_dev_exit(idx);
352}
353EXPORT_SYMBOL(mipi_dbi_enable_flush);
354
355static void mipi_dbi_blank(struct mipi_dbi_dev *dbidev)
356{
357 struct drm_device *drm = &dbidev->drm;
358 u16 height = drm->mode_config.min_height;
359 u16 width = drm->mode_config.min_width;
360 struct mipi_dbi *dbi = &dbidev->dbi;
361 size_t len = width * height * 2;
362 int idx;
363
364 if (!drm_dev_enter(drm, &idx))
365 return;
366
367 memset(dbidev->tx_buf, 0, len);
368
369 mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS, 0, 0,
370 (width >> 8) & 0xFF, (width - 1) & 0xFF);
371 mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS, 0, 0,
372 (height >> 8) & 0xFF, (height - 1) & 0xFF);
373 mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START,
374 (u8 *)dbidev->tx_buf, len);
375
376 drm_dev_exit(idx);
377}
378
379/**
380 * mipi_dbi_pipe_disable - MIPI DBI pipe disable helper
381 * @pipe: Display pipe
382 *
383 * This function disables backlight if present, if not the display memory is
384 * blanked. The regulator is disabled if in use. Drivers can use this as their
385 * &drm_simple_display_pipe_funcs->disable callback.
386 */
387void mipi_dbi_pipe_disable(struct drm_simple_display_pipe *pipe)
388{
389 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
390
391 if (!dbidev->enabled)
392 return;
393
394 DRM_DEBUG_KMS("\n");
395
396 dbidev->enabled = false;
397
398 if (dbidev->backlight)
399 backlight_disable(dbidev->backlight);
400 else
401 mipi_dbi_blank(dbidev);
402
403 if (dbidev->regulator)
404 regulator_disable(dbidev->regulator);
405}
406EXPORT_SYMBOL(mipi_dbi_pipe_disable);
407
408static int mipi_dbi_connector_get_modes(struct drm_connector *connector)
409{
410 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(connector->dev);
411 struct drm_display_mode *mode;
412
413 mode = drm_mode_duplicate(connector->dev, &dbidev->mode);
414 if (!mode) {
415 DRM_ERROR("Failed to duplicate mode\n");
416 return 0;
417 }
418
419 if (mode->name[0] == '\0')
420 drm_mode_set_name(mode);
421
422 mode->type |= DRM_MODE_TYPE_PREFERRED;
423 drm_mode_probed_add(connector, mode);
424
425 if (mode->width_mm) {
426 connector->display_info.width_mm = mode->width_mm;
427 connector->display_info.height_mm = mode->height_mm;
428 }
429
430 return 1;
431}
432
433static const struct drm_connector_helper_funcs mipi_dbi_connector_hfuncs = {
434 .get_modes = mipi_dbi_connector_get_modes,
435};
436
437static const struct drm_connector_funcs mipi_dbi_connector_funcs = {
438 .reset = drm_atomic_helper_connector_reset,
439 .fill_modes = drm_helper_probe_single_connector_modes,
440 .destroy = drm_connector_cleanup,
441 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
442 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
443};
444
445static int mipi_dbi_rotate_mode(struct drm_display_mode *mode,
446 unsigned int rotation)
447{
448 if (rotation == 0 || rotation == 180) {
449 return 0;
450 } else if (rotation == 90 || rotation == 270) {
451 swap(mode->hdisplay, mode->vdisplay);
452 swap(mode->hsync_start, mode->vsync_start);
453 swap(mode->hsync_end, mode->vsync_end);
454 swap(mode->htotal, mode->vtotal);
455 swap(mode->width_mm, mode->height_mm);
456 return 0;
457 } else {
458 return -EINVAL;
459 }
460}
461
462static const struct drm_mode_config_funcs mipi_dbi_mode_config_funcs = {
463 .fb_create = drm_gem_fb_create_with_dirty,
464 .atomic_check = drm_atomic_helper_check,
465 .atomic_commit = drm_atomic_helper_commit,
466};
467
468static const uint32_t mipi_dbi_formats[] = {
469 DRM_FORMAT_RGB565,
470 DRM_FORMAT_XRGB8888,
471};
472
473/**
474 * mipi_dbi_dev_init_with_formats - MIPI DBI device initialization with custom formats
475 * @dbidev: MIPI DBI device structure to initialize
476 * @funcs: Display pipe functions
477 * @formats: Array of supported formats (DRM_FORMAT\_\*).
478 * @format_count: Number of elements in @formats
479 * @mode: Display mode
480 * @rotation: Initial rotation in degrees Counter Clock Wise
481 * @tx_buf_size: Allocate a transmit buffer of this size.
482 *
483 * This function sets up a &drm_simple_display_pipe with a &drm_connector that
484 * has one fixed &drm_display_mode which is rotated according to @rotation.
485 * This mode is used to set the mode config min/max width/height properties.
486 *
487 * Use mipi_dbi_dev_init() if you don't need custom formats.
488 *
489 * Note:
490 * Some of the helper functions expects RGB565 to be the default format and the
491 * transmit buffer sized to fit that.
492 *
493 * Returns:
494 * Zero on success, negative error code on failure.
495 */
496int mipi_dbi_dev_init_with_formats(struct mipi_dbi_dev *dbidev,
497 const struct drm_simple_display_pipe_funcs *funcs,
498 const uint32_t *formats, unsigned int format_count,
499 const struct drm_display_mode *mode,
500 unsigned int rotation, size_t tx_buf_size)
501{
502 static const uint64_t modifiers[] = {
503 DRM_FORMAT_MOD_LINEAR,
504 DRM_FORMAT_MOD_INVALID
505 };
506 struct drm_device *drm = &dbidev->drm;
507 int ret;
508
509 if (!dbidev->dbi.command)
510 return -EINVAL;
511
512 dbidev->tx_buf = devm_kmalloc(drm->dev, tx_buf_size, GFP_KERNEL);
513 if (!dbidev->tx_buf)
514 return -ENOMEM;
515
516 drm_mode_copy(&dbidev->mode, mode);
517 ret = mipi_dbi_rotate_mode(&dbidev->mode, rotation);
518 if (ret) {
519 DRM_ERROR("Illegal rotation value %u\n", rotation);
520 return -EINVAL;
521 }
522
523 drm_connector_helper_add(&dbidev->connector, &mipi_dbi_connector_hfuncs);
524 ret = drm_connector_init(drm, &dbidev->connector, &mipi_dbi_connector_funcs,
525 DRM_MODE_CONNECTOR_SPI);
526 if (ret)
527 return ret;
528
529 ret = drm_simple_display_pipe_init(drm, &dbidev->pipe, funcs, formats, format_count,
530 modifiers, &dbidev->connector);
531 if (ret)
532 return ret;
533
534 drm_plane_enable_fb_damage_clips(&dbidev->pipe.plane);
535
536 drm->mode_config.funcs = &mipi_dbi_mode_config_funcs;
537 drm->mode_config.min_width = dbidev->mode.hdisplay;
538 drm->mode_config.max_width = dbidev->mode.hdisplay;
539 drm->mode_config.min_height = dbidev->mode.vdisplay;
540 drm->mode_config.max_height = dbidev->mode.vdisplay;
541 dbidev->rotation = rotation;
542
543 DRM_DEBUG_KMS("rotation = %u\n", rotation);
544
545 return 0;
546}
547EXPORT_SYMBOL(mipi_dbi_dev_init_with_formats);
548
549/**
550 * mipi_dbi_dev_init - MIPI DBI device initialization
551 * @dbidev: MIPI DBI device structure to initialize
552 * @funcs: Display pipe functions
553 * @mode: Display mode
554 * @rotation: Initial rotation in degrees Counter Clock Wise
555 *
556 * This function sets up a &drm_simple_display_pipe with a &drm_connector that
557 * has one fixed &drm_display_mode which is rotated according to @rotation.
558 * This mode is used to set the mode config min/max width/height properties.
559 * Additionally &mipi_dbi.tx_buf is allocated.
560 *
561 * Supported formats: Native RGB565 and emulated XRGB8888.
562 *
563 * Returns:
564 * Zero on success, negative error code on failure.
565 */
566int mipi_dbi_dev_init(struct mipi_dbi_dev *dbidev,
567 const struct drm_simple_display_pipe_funcs *funcs,
568 const struct drm_display_mode *mode, unsigned int rotation)
569{
570 size_t bufsize = mode->vdisplay * mode->hdisplay * sizeof(u16);
571
572 dbidev->drm.mode_config.preferred_depth = 16;
573
574 return mipi_dbi_dev_init_with_formats(dbidev, funcs, mipi_dbi_formats,
575 ARRAY_SIZE(mipi_dbi_formats), mode,
576 rotation, bufsize);
577}
578EXPORT_SYMBOL(mipi_dbi_dev_init);
579
580/**
581 * mipi_dbi_release - DRM driver release helper
582 * @drm: DRM device
583 *
584 * This function finalizes and frees &mipi_dbi.
585 *
586 * Drivers can use this as their &drm_driver->release callback.
587 */
588void mipi_dbi_release(struct drm_device *drm)
589{
590 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(drm);
591
592 DRM_DEBUG_DRIVER("\n");
593
594 drm_mode_config_cleanup(drm);
595 drm_dev_fini(drm);
596 kfree(dbidev);
597}
598EXPORT_SYMBOL(mipi_dbi_release);
599
600/**
601 * mipi_dbi_hw_reset - Hardware reset of controller
602 * @dbi: MIPI DBI structure
603 *
604 * Reset controller if the &mipi_dbi->reset gpio is set.
605 */
606void mipi_dbi_hw_reset(struct mipi_dbi *dbi)
607{
608 if (!dbi->reset)
609 return;
610
611 gpiod_set_value_cansleep(dbi->reset, 0);
612 usleep_range(20, 1000);
613 gpiod_set_value_cansleep(dbi->reset, 1);
614 msleep(120);
615}
616EXPORT_SYMBOL(mipi_dbi_hw_reset);
617
618/**
619 * mipi_dbi_display_is_on - Check if display is on
620 * @dbi: MIPI DBI structure
621 *
622 * This function checks the Power Mode register (if readable) to see if
623 * display output is turned on. This can be used to see if the bootloader
624 * has already turned on the display avoiding flicker when the pipeline is
625 * enabled.
626 *
627 * Returns:
628 * true if the display can be verified to be on, false otherwise.
629 */
630bool mipi_dbi_display_is_on(struct mipi_dbi *dbi)
631{
632 u8 val;
633
634 if (mipi_dbi_command_read(dbi, MIPI_DCS_GET_POWER_MODE, &val))
635 return false;
636
637 val &= ~DCS_POWER_MODE_RESERVED_MASK;
638
639 /* The poweron/reset value is 08h DCS_POWER_MODE_DISPLAY_NORMAL_MODE */
640 if (val != (DCS_POWER_MODE_DISPLAY |
641 DCS_POWER_MODE_DISPLAY_NORMAL_MODE | DCS_POWER_MODE_SLEEP_MODE))
642 return false;
643
644 DRM_DEBUG_DRIVER("Display is ON\n");
645
646 return true;
647}
648EXPORT_SYMBOL(mipi_dbi_display_is_on);
649
650static int mipi_dbi_poweron_reset_conditional(struct mipi_dbi_dev *dbidev, bool cond)
651{
652 struct device *dev = dbidev->drm.dev;
653 struct mipi_dbi *dbi = &dbidev->dbi;
654 int ret;
655
656 if (dbidev->regulator) {
657 ret = regulator_enable(dbidev->regulator);
658 if (ret) {
659 DRM_DEV_ERROR(dev, "Failed to enable regulator (%d)\n", ret);
660 return ret;
661 }
662 }
663
664 if (cond && mipi_dbi_display_is_on(dbi))
665 return 1;
666
667 mipi_dbi_hw_reset(dbi);
668 ret = mipi_dbi_command(dbi, MIPI_DCS_SOFT_RESET);
669 if (ret) {
670 DRM_DEV_ERROR(dev, "Failed to send reset command (%d)\n", ret);
671 if (dbidev->regulator)
672 regulator_disable(dbidev->regulator);
673 return ret;
674 }
675
676 /*
677 * If we did a hw reset, we know the controller is in Sleep mode and
678 * per MIPI DSC spec should wait 5ms after soft reset. If we didn't,
679 * we assume worst case and wait 120ms.
680 */
681 if (dbi->reset)
682 usleep_range(5000, 20000);
683 else
684 msleep(120);
685
686 return 0;
687}
688
689/**
690 * mipi_dbi_poweron_reset - MIPI DBI poweron and reset
691 * @dbidev: MIPI DBI device structure
692 *
693 * This function enables the regulator if used and does a hardware and software
694 * reset.
695 *
696 * Returns:
697 * Zero on success, or a negative error code.
698 */
699int mipi_dbi_poweron_reset(struct mipi_dbi_dev *dbidev)
700{
701 return mipi_dbi_poweron_reset_conditional(dbidev, false);
702}
703EXPORT_SYMBOL(mipi_dbi_poweron_reset);
704
705/**
706 * mipi_dbi_poweron_conditional_reset - MIPI DBI poweron and conditional reset
707 * @dbidev: MIPI DBI device structure
708 *
709 * This function enables the regulator if used and if the display is off, it
710 * does a hardware and software reset. If mipi_dbi_display_is_on() determines
711 * that the display is on, no reset is performed.
712 *
713 * Returns:
714 * Zero if the controller was reset, 1 if the display was already on, or a
715 * negative error code.
716 */
717int mipi_dbi_poweron_conditional_reset(struct mipi_dbi_dev *dbidev)
718{
719 return mipi_dbi_poweron_reset_conditional(dbidev, true);
720}
721EXPORT_SYMBOL(mipi_dbi_poweron_conditional_reset);
722
723#if IS_ENABLED(CONFIG_SPI)
724
725/**
726 * mipi_dbi_spi_cmd_max_speed - get the maximum SPI bus speed
727 * @spi: SPI device
728 * @len: The transfer buffer length.
729 *
730 * Many controllers have a max speed of 10MHz, but can be pushed way beyond
731 * that. Increase reliability by running pixel data at max speed and the rest
732 * at 10MHz, preventing transfer glitches from messing up the init settings.
733 */
734u32 mipi_dbi_spi_cmd_max_speed(struct spi_device *spi, size_t len)
735{
736 if (len > 64)
737 return 0; /* use default */
738
739 return min_t(u32, 10000000, spi->max_speed_hz);
740}
741EXPORT_SYMBOL(mipi_dbi_spi_cmd_max_speed);
742
743static bool mipi_dbi_machine_little_endian(void)
744{
745#if defined(__LITTLE_ENDIAN)
746 return true;
747#else
748 return false;
749#endif
750}
751
752/*
753 * MIPI DBI Type C Option 1
754 *
755 * If the SPI controller doesn't have 9 bits per word support,
756 * use blocks of 9 bytes to send 8x 9-bit words using a 8-bit SPI transfer.
757 * Pad partial blocks with MIPI_DCS_NOP (zero).
758 * This is how the D/C bit (x) is added:
759 * x7654321
760 * 0x765432
761 * 10x76543
762 * 210x7654
763 * 3210x765
764 * 43210x76
765 * 543210x7
766 * 6543210x
767 * 76543210
768 */
769
770static int mipi_dbi_spi1e_transfer(struct mipi_dbi *dbi, int dc,
771 const void *buf, size_t len,
772 unsigned int bpw)
773{
774 bool swap_bytes = (bpw == 16 && mipi_dbi_machine_little_endian());
775 size_t chunk, max_chunk = dbi->tx_buf9_len;
776 struct spi_device *spi = dbi->spi;
777 struct spi_transfer tr = {
778 .tx_buf = dbi->tx_buf9,
779 .bits_per_word = 8,
780 };
781 struct spi_message m;
782 const u8 *src = buf;
783 int i, ret;
784 u8 *dst;
785
786 if (drm_debug & DRM_UT_DRIVER)
787 pr_debug("[drm:%s] dc=%d, max_chunk=%zu, transfers:\n",
788 __func__, dc, max_chunk);
789
790 tr.speed_hz = mipi_dbi_spi_cmd_max_speed(spi, len);
791 spi_message_init_with_transfers(&m, &tr, 1);
792
793 if (!dc) {
794 if (WARN_ON_ONCE(len != 1))
795 return -EINVAL;
796
797 /* Command: pad no-op's (zeroes) at beginning of block */
798 dst = dbi->tx_buf9;
799 memset(dst, 0, 9);
800 dst[8] = *src;
801 tr.len = 9;
802
803 return spi_sync(spi, &m);
804 }
805
806 /* max with room for adding one bit per byte */
807 max_chunk = max_chunk / 9 * 8;
808 /* but no bigger than len */
809 max_chunk = min(max_chunk, len);
810 /* 8 byte blocks */
811 max_chunk = max_t(size_t, 8, max_chunk & ~0x7);
812
813 while (len) {
814 size_t added = 0;
815
816 chunk = min(len, max_chunk);
817 len -= chunk;
818 dst = dbi->tx_buf9;
819
820 if (chunk < 8) {
821 u8 val, carry = 0;
822
823 /* Data: pad no-op's (zeroes) at end of block */
824 memset(dst, 0, 9);
825
826 if (swap_bytes) {
827 for (i = 1; i < (chunk + 1); i++) {
828 val = src[1];
829 *dst++ = carry | BIT(8 - i) | (val >> i);
830 carry = val << (8 - i);
831 i++;
832 val = src[0];
833 *dst++ = carry | BIT(8 - i) | (val >> i);
834 carry = val << (8 - i);
835 src += 2;
836 }
837 *dst++ = carry;
838 } else {
839 for (i = 1; i < (chunk + 1); i++) {
840 val = *src++;
841 *dst++ = carry | BIT(8 - i) | (val >> i);
842 carry = val << (8 - i);
843 }
844 *dst++ = carry;
845 }
846
847 chunk = 8;
848 added = 1;
849 } else {
850 for (i = 0; i < chunk; i += 8) {
851 if (swap_bytes) {
852 *dst++ = BIT(7) | (src[1] >> 1);
853 *dst++ = (src[1] << 7) | BIT(6) | (src[0] >> 2);
854 *dst++ = (src[0] << 6) | BIT(5) | (src[3] >> 3);
855 *dst++ = (src[3] << 5) | BIT(4) | (src[2] >> 4);
856 *dst++ = (src[2] << 4) | BIT(3) | (src[5] >> 5);
857 *dst++ = (src[5] << 3) | BIT(2) | (src[4] >> 6);
858 *dst++ = (src[4] << 2) | BIT(1) | (src[7] >> 7);
859 *dst++ = (src[7] << 1) | BIT(0);
860 *dst++ = src[6];
861 } else {
862 *dst++ = BIT(7) | (src[0] >> 1);
863 *dst++ = (src[0] << 7) | BIT(6) | (src[1] >> 2);
864 *dst++ = (src[1] << 6) | BIT(5) | (src[2] >> 3);
865 *dst++ = (src[2] << 5) | BIT(4) | (src[3] >> 4);
866 *dst++ = (src[3] << 4) | BIT(3) | (src[4] >> 5);
867 *dst++ = (src[4] << 3) | BIT(2) | (src[5] >> 6);
868 *dst++ = (src[5] << 2) | BIT(1) | (src[6] >> 7);
869 *dst++ = (src[6] << 1) | BIT(0);
870 *dst++ = src[7];
871 }
872
873 src += 8;
874 added++;
875 }
876 }
877
878 tr.len = chunk + added;
879
880 ret = spi_sync(spi, &m);
881 if (ret)
882 return ret;
883 }
884
885 return 0;
886}
887
888static int mipi_dbi_spi1_transfer(struct mipi_dbi *dbi, int dc,
889 const void *buf, size_t len,
890 unsigned int bpw)
891{
892 struct spi_device *spi = dbi->spi;
893 struct spi_transfer tr = {
894 .bits_per_word = 9,
895 };
896 const u16 *src16 = buf;
897 const u8 *src8 = buf;
898 struct spi_message m;
899 size_t max_chunk;
900 u16 *dst16;
901 int ret;
902
903 if (!spi_is_bpw_supported(spi, 9))
904 return mipi_dbi_spi1e_transfer(dbi, dc, buf, len, bpw);
905
906 tr.speed_hz = mipi_dbi_spi_cmd_max_speed(spi, len);
907 max_chunk = dbi->tx_buf9_len;
908 dst16 = dbi->tx_buf9;
909
910 if (drm_debug & DRM_UT_DRIVER)
911 pr_debug("[drm:%s] dc=%d, max_chunk=%zu, transfers:\n",
912 __func__, dc, max_chunk);
913
914 max_chunk = min(max_chunk / 2, len);
915
916 spi_message_init_with_transfers(&m, &tr, 1);
917 tr.tx_buf = dst16;
918
919 while (len) {
920 size_t chunk = min(len, max_chunk);
921 unsigned int i;
922
923 if (bpw == 16 && mipi_dbi_machine_little_endian()) {
924 for (i = 0; i < (chunk * 2); i += 2) {
925 dst16[i] = *src16 >> 8;
926 dst16[i + 1] = *src16++ & 0xFF;
927 if (dc) {
928 dst16[i] |= 0x0100;
929 dst16[i + 1] |= 0x0100;
930 }
931 }
932 } else {
933 for (i = 0; i < chunk; i++) {
934 dst16[i] = *src8++;
935 if (dc)
936 dst16[i] |= 0x0100;
937 }
938 }
939
940 tr.len = chunk;
941 len -= chunk;
942
943 ret = spi_sync(spi, &m);
944 if (ret)
945 return ret;
946 }
947
948 return 0;
949}
950
951static int mipi_dbi_typec1_command(struct mipi_dbi *dbi, u8 *cmd,
952 u8 *parameters, size_t num)
953{
954 unsigned int bpw = (*cmd == MIPI_DCS_WRITE_MEMORY_START) ? 16 : 8;
955 int ret;
956
957 if (mipi_dbi_command_is_read(dbi, *cmd))
958 return -ENOTSUPP;
959
960 MIPI_DBI_DEBUG_COMMAND(*cmd, parameters, num);
961
962 ret = mipi_dbi_spi1_transfer(dbi, 0, cmd, 1, 8);
963 if (ret || !num)
964 return ret;
965
966 return mipi_dbi_spi1_transfer(dbi, 1, parameters, num, bpw);
967}
968
969/* MIPI DBI Type C Option 3 */
970
971static int mipi_dbi_typec3_command_read(struct mipi_dbi *dbi, u8 *cmd,
972 u8 *data, size_t len)
973{
974 struct spi_device *spi = dbi->spi;
975 u32 speed_hz = min_t(u32, MIPI_DBI_MAX_SPI_READ_SPEED,
976 spi->max_speed_hz / 2);
977 struct spi_transfer tr[2] = {
978 {
979 .speed_hz = speed_hz,
980 .tx_buf = cmd,
981 .len = 1,
982 }, {
983 .speed_hz = speed_hz,
984 .len = len,
985 },
986 };
987 struct spi_message m;
988 u8 *buf;
989 int ret;
990
991 if (!len)
992 return -EINVAL;
993
994 /*
995 * Support non-standard 24-bit and 32-bit Nokia read commands which
996 * start with a dummy clock, so we need to read an extra byte.
997 */
998 if (*cmd == MIPI_DCS_GET_DISPLAY_ID ||
999 *cmd == MIPI_DCS_GET_DISPLAY_STATUS) {
1000 if (!(len == 3 || len == 4))
1001 return -EINVAL;
1002
1003 tr[1].len = len + 1;
1004 }
1005
1006 buf = kmalloc(tr[1].len, GFP_KERNEL);
1007 if (!buf)
1008 return -ENOMEM;
1009
1010 tr[1].rx_buf = buf;
1011 gpiod_set_value_cansleep(dbi->dc, 0);
1012
1013 spi_message_init_with_transfers(&m, tr, ARRAY_SIZE(tr));
1014 ret = spi_sync(spi, &m);
1015 if (ret)
1016 goto err_free;
1017
1018 if (tr[1].len == len) {
1019 memcpy(data, buf, len);
1020 } else {
1021 unsigned int i;
1022
1023 for (i = 0; i < len; i++)
1024 data[i] = (buf[i] << 1) | !!(buf[i + 1] & BIT(7));
1025 }
1026
1027 MIPI_DBI_DEBUG_COMMAND(*cmd, data, len);
1028
1029err_free:
1030 kfree(buf);
1031
1032 return ret;
1033}
1034
1035static int mipi_dbi_typec3_command(struct mipi_dbi *dbi, u8 *cmd,
1036 u8 *par, size_t num)
1037{
1038 struct spi_device *spi = dbi->spi;
1039 unsigned int bpw = 8;
1040 u32 speed_hz;
1041 int ret;
1042
1043 if (mipi_dbi_command_is_read(dbi, *cmd))
1044 return mipi_dbi_typec3_command_read(dbi, cmd, par, num);
1045
1046 MIPI_DBI_DEBUG_COMMAND(*cmd, par, num);
1047
1048 gpiod_set_value_cansleep(dbi->dc, 0);
1049 speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 1);
1050 ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, cmd, 1);
1051 if (ret || !num)
1052 return ret;
1053
1054 if (*cmd == MIPI_DCS_WRITE_MEMORY_START && !dbi->swap_bytes)
1055 bpw = 16;
1056
1057 gpiod_set_value_cansleep(dbi->dc, 1);
1058 speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
1059
1060 return mipi_dbi_spi_transfer(spi, speed_hz, bpw, par, num);
1061}
1062
1063/**
1064 * mipi_dbi_spi_init - Initialize MIPI DBI SPI interface
1065 * @spi: SPI device
1066 * @dbi: MIPI DBI structure to initialize
1067 * @dc: D/C gpio (optional)
1068 *
1069 * This function sets &mipi_dbi->command, enables &mipi_dbi->read_commands for the
1070 * usual read commands. It should be followed by a call to mipi_dbi_dev_init() or
1071 * a driver-specific init.
1072 *
1073 * If @dc is set, a Type C Option 3 interface is assumed, if not
1074 * Type C Option 1.
1075 *
1076 * If the SPI master driver doesn't support the necessary bits per word,
1077 * the following transformation is used:
1078 *
1079 * - 9-bit: reorder buffer as 9x 8-bit words, padded with no-op command.
1080 * - 16-bit: if big endian send as 8-bit, if little endian swap bytes
1081 *
1082 * Returns:
1083 * Zero on success, negative error code on failure.
1084 */
1085int mipi_dbi_spi_init(struct spi_device *spi, struct mipi_dbi *dbi,
1086 struct gpio_desc *dc)
1087{
1088 struct device *dev = &spi->dev;
1089 int ret;
1090
1091 /*
1092 * Even though it's not the SPI device that does DMA (the master does),
1093 * the dma mask is necessary for the dma_alloc_wc() in
1094 * drm_gem_cma_create(). The dma_addr returned will be a physical
1095 * address which might be different from the bus address, but this is
1096 * not a problem since the address will not be used.
1097 * The virtual address is used in the transfer and the SPI core
1098 * re-maps it on the SPI master device using the DMA streaming API
1099 * (spi_map_buf()).
1100 */
1101 if (!dev->coherent_dma_mask) {
1102 ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
1103 if (ret) {
1104 dev_warn(dev, "Failed to set dma mask %d\n", ret);
1105 return ret;
1106 }
1107 }
1108
1109 dbi->spi = spi;
1110 dbi->read_commands = mipi_dbi_dcs_read_commands;
1111
1112 if (dc) {
1113 dbi->command = mipi_dbi_typec3_command;
1114 dbi->dc = dc;
1115 if (mipi_dbi_machine_little_endian() && !spi_is_bpw_supported(spi, 16))
1116 dbi->swap_bytes = true;
1117 } else {
1118 dbi->command = mipi_dbi_typec1_command;
1119 dbi->tx_buf9_len = SZ_16K;
1120 dbi->tx_buf9 = devm_kmalloc(dev, dbi->tx_buf9_len, GFP_KERNEL);
1121 if (!dbi->tx_buf9)
1122 return -ENOMEM;
1123 }
1124
1125 mutex_init(&dbi->cmdlock);
1126
1127 DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000);
1128
1129 return 0;
1130}
1131EXPORT_SYMBOL(mipi_dbi_spi_init);
1132
1133/**
1134 * mipi_dbi_spi_transfer - SPI transfer helper
1135 * @spi: SPI device
1136 * @speed_hz: Override speed (optional)
1137 * @bpw: Bits per word
1138 * @buf: Buffer to transfer
1139 * @len: Buffer length
1140 *
1141 * This SPI transfer helper breaks up the transfer of @buf into chunks which
1142 * the SPI controller driver can handle.
1143 *
1144 * Returns:
1145 * Zero on success, negative error code on failure.
1146 */
1147int mipi_dbi_spi_transfer(struct spi_device *spi, u32 speed_hz,
1148 u8 bpw, const void *buf, size_t len)
1149{
1150 size_t max_chunk = spi_max_transfer_size(spi);
1151 struct spi_transfer tr = {
1152 .bits_per_word = bpw,
1153 .speed_hz = speed_hz,
1154 };
1155 struct spi_message m;
1156 size_t chunk;
1157 int ret;
1158
1159 spi_message_init_with_transfers(&m, &tr, 1);
1160
1161 while (len) {
1162 chunk = min(len, max_chunk);
1163
1164 tr.tx_buf = buf;
1165 tr.len = chunk;
1166 buf += chunk;
1167 len -= chunk;
1168
1169 ret = spi_sync(spi, &m);
1170 if (ret)
1171 return ret;
1172 }
1173
1174 return 0;
1175}
1176EXPORT_SYMBOL(mipi_dbi_spi_transfer);
1177
1178#endif /* CONFIG_SPI */
1179
1180#ifdef CONFIG_DEBUG_FS
1181
1182static ssize_t mipi_dbi_debugfs_command_write(struct file *file,
1183 const char __user *ubuf,
1184 size_t count, loff_t *ppos)
1185{
1186 struct seq_file *m = file->private_data;
1187 struct mipi_dbi_dev *dbidev = m->private;
1188 u8 val, cmd = 0, parameters[64];
1189 char *buf, *pos, *token;
1190 unsigned int i;
1191 int ret, idx;
1192
1193 if (!drm_dev_enter(&dbidev->drm, &idx))
1194 return -ENODEV;
1195
1196 buf = memdup_user_nul(ubuf, count);
1197 if (IS_ERR(buf)) {
1198 ret = PTR_ERR(buf);
1199 goto err_exit;
1200 }
1201
1202 /* strip trailing whitespace */
1203 for (i = count - 1; i > 0; i--)
1204 if (isspace(buf[i]))
1205 buf[i] = '\0';
1206 else
1207 break;
1208 i = 0;
1209 pos = buf;
1210 while (pos) {
1211 token = strsep(&pos, " ");
1212 if (!token) {
1213 ret = -EINVAL;
1214 goto err_free;
1215 }
1216
1217 ret = kstrtou8(token, 16, &val);
1218 if (ret < 0)
1219 goto err_free;
1220
1221 if (token == buf)
1222 cmd = val;
1223 else
1224 parameters[i++] = val;
1225
1226 if (i == 64) {
1227 ret = -E2BIG;
1228 goto err_free;
1229 }
1230 }
1231
1232 ret = mipi_dbi_command_buf(&dbidev->dbi, cmd, parameters, i);
1233
1234err_free:
1235 kfree(buf);
1236err_exit:
1237 drm_dev_exit(idx);
1238
1239 return ret < 0 ? ret : count;
1240}
1241
1242static int mipi_dbi_debugfs_command_show(struct seq_file *m, void *unused)
1243{
1244 struct mipi_dbi_dev *dbidev = m->private;
1245 struct mipi_dbi *dbi = &dbidev->dbi;
1246 u8 cmd, val[4];
1247 int ret, idx;
1248 size_t len;
1249
1250 if (!drm_dev_enter(&dbidev->drm, &idx))
1251 return -ENODEV;
1252
1253 for (cmd = 0; cmd < 255; cmd++) {
1254 if (!mipi_dbi_command_is_read(dbi, cmd))
1255 continue;
1256
1257 switch (cmd) {
1258 case MIPI_DCS_READ_MEMORY_START:
1259 case MIPI_DCS_READ_MEMORY_CONTINUE:
1260 len = 2;
1261 break;
1262 case MIPI_DCS_GET_DISPLAY_ID:
1263 len = 3;
1264 break;
1265 case MIPI_DCS_GET_DISPLAY_STATUS:
1266 len = 4;
1267 break;
1268 default:
1269 len = 1;
1270 break;
1271 }
1272
1273 seq_printf(m, "%02x: ", cmd);
1274 ret = mipi_dbi_command_buf(dbi, cmd, val, len);
1275 if (ret) {
1276 seq_puts(m, "XX\n");
1277 continue;
1278 }
1279 seq_printf(m, "%*phN\n", (int)len, val);
1280 }
1281
1282 drm_dev_exit(idx);
1283
1284 return 0;
1285}
1286
1287static int mipi_dbi_debugfs_command_open(struct inode *inode,
1288 struct file *file)
1289{
1290 return single_open(file, mipi_dbi_debugfs_command_show,
1291 inode->i_private);
1292}
1293
1294static const struct file_operations mipi_dbi_debugfs_command_fops = {
1295 .owner = THIS_MODULE,
1296 .open = mipi_dbi_debugfs_command_open,
1297 .read = seq_read,
1298 .llseek = seq_lseek,
1299 .release = single_release,
1300 .write = mipi_dbi_debugfs_command_write,
1301};
1302
1303/**
1304 * mipi_dbi_debugfs_init - Create debugfs entries
1305 * @minor: DRM minor
1306 *
1307 * This function creates a 'command' debugfs file for sending commands to the
1308 * controller or getting the read command values.
1309 * Drivers can use this as their &drm_driver->debugfs_init callback.
1310 *
1311 * Returns:
1312 * Zero on success, negative error code on failure.
1313 */
1314int mipi_dbi_debugfs_init(struct drm_minor *minor)
1315{
1316 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(minor->dev);
1317 umode_t mode = S_IFREG | S_IWUSR;
1318
1319 if (dbidev->dbi.read_commands)
1320 mode |= S_IRUGO;
1321 debugfs_create_file("command", mode, minor->debugfs_root, dbidev,
1322 &mipi_dbi_debugfs_command_fops);
1323
1324 return 0;
1325}
1326EXPORT_SYMBOL(mipi_dbi_debugfs_init);
1327
1328#endif
1329
1330MODULE_LICENSE("GPL");