Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
// SPDX-License-Identifier: GPL-2.0
/*
 * Raydium RM67191 MIPI-DSI panel driver
 *
 * Copyright 2019 NXP
 */

#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>

#include <video/mipi_display.h>
#include <video/of_videomode.h>
#include <video/videomode.h>

#include <drm/drm_crtc.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>

/* Panel specific color-format bits */
#define COL_FMT_16BPP 0x55
#define COL_FMT_18BPP 0x66
#define COL_FMT_24BPP 0x77

/* Write Manufacture Command Set Control */
#define WRMAUCCTR 0xFE

/* Manufacturer Command Set pages (CMD2) */
struct cmd_set_entry {
	u8 cmd;
	u8 param;
};

/*
 * There is no description in the Reference Manual about these commands.
 * We received them from vendor, so just use them as is.
 */
static const struct cmd_set_entry manufacturer_cmd_set[] = {
	{0xFE, 0x0B},
	{0x28, 0x40},
	{0x29, 0x4F},
	{0xFE, 0x0E},
	{0x4B, 0x00},
	{0x4C, 0x0F},
	{0x4D, 0x20},
	{0x4E, 0x40},
	{0x4F, 0x60},
	{0x50, 0xA0},
	{0x51, 0xC0},
	{0x52, 0xE0},
	{0x53, 0xFF},
	{0xFE, 0x0D},
	{0x18, 0x08},
	{0x42, 0x00},
	{0x08, 0x41},
	{0x46, 0x02},
	{0x72, 0x09},
	{0xFE, 0x0A},
	{0x24, 0x17},
	{0x04, 0x07},
	{0x1A, 0x0C},
	{0x0F, 0x44},
	{0xFE, 0x04},
	{0x00, 0x0C},
	{0x05, 0x08},
	{0x06, 0x08},
	{0x08, 0x08},
	{0x09, 0x08},
	{0x0A, 0xE6},
	{0x0B, 0x8C},
	{0x1A, 0x12},
	{0x1E, 0xE0},
	{0x29, 0x93},
	{0x2A, 0x93},
	{0x2F, 0x02},
	{0x31, 0x02},
	{0x33, 0x05},
	{0x37, 0x2D},
	{0x38, 0x2D},
	{0x3A, 0x1E},
	{0x3B, 0x1E},
	{0x3D, 0x27},
	{0x3F, 0x80},
	{0x40, 0x40},
	{0x41, 0xE0},
	{0x4F, 0x2F},
	{0x50, 0x1E},
	{0xFE, 0x06},
	{0x00, 0xCC},
	{0x05, 0x05},
	{0x07, 0xA2},
	{0x08, 0xCC},
	{0x0D, 0x03},
	{0x0F, 0xA2},
	{0x32, 0xCC},
	{0x37, 0x05},
	{0x39, 0x83},
	{0x3A, 0xCC},
	{0x41, 0x04},
	{0x43, 0x83},
	{0x44, 0xCC},
	{0x49, 0x05},
	{0x4B, 0xA2},
	{0x4C, 0xCC},
	{0x51, 0x03},
	{0x53, 0xA2},
	{0x75, 0xCC},
	{0x7A, 0x03},
	{0x7C, 0x83},
	{0x7D, 0xCC},
	{0x82, 0x02},
	{0x84, 0x83},
	{0x85, 0xEC},
	{0x86, 0x0F},
	{0x87, 0xFF},
	{0x88, 0x00},
	{0x8A, 0x02},
	{0x8C, 0xA2},
	{0x8D, 0xEA},
	{0x8E, 0x01},
	{0x8F, 0xE8},
	{0xFE, 0x06},
	{0x90, 0x0A},
	{0x92, 0x06},
	{0x93, 0xA0},
	{0x94, 0xA8},
	{0x95, 0xEC},
	{0x96, 0x0F},
	{0x97, 0xFF},
	{0x98, 0x00},
	{0x9A, 0x02},
	{0x9C, 0xA2},
	{0xAC, 0x04},
	{0xFE, 0x06},
	{0xB1, 0x12},
	{0xB2, 0x17},
	{0xB3, 0x17},
	{0xB4, 0x17},
	{0xB5, 0x17},
	{0xB6, 0x11},
	{0xB7, 0x08},
	{0xB8, 0x09},
	{0xB9, 0x06},
	{0xBA, 0x07},
	{0xBB, 0x17},
	{0xBC, 0x17},
	{0xBD, 0x17},
	{0xBE, 0x17},
	{0xBF, 0x17},
	{0xC0, 0x17},
	{0xC1, 0x17},
	{0xC2, 0x17},
	{0xC3, 0x17},
	{0xC4, 0x0F},
	{0xC5, 0x0E},
	{0xC6, 0x00},
	{0xC7, 0x01},
	{0xC8, 0x10},
	{0xFE, 0x06},
	{0x95, 0xEC},
	{0x8D, 0xEE},
	{0x44, 0xEC},
	{0x4C, 0xEC},
	{0x32, 0xEC},
	{0x3A, 0xEC},
	{0x7D, 0xEC},
	{0x75, 0xEC},
	{0x00, 0xEC},
	{0x08, 0xEC},
	{0x85, 0xEC},
	{0xA6, 0x21},
	{0xA7, 0x05},
	{0xA9, 0x06},
	{0x82, 0x06},
	{0x41, 0x06},
	{0x7A, 0x07},
	{0x37, 0x07},
	{0x05, 0x06},
	{0x49, 0x06},
	{0x0D, 0x04},
	{0x51, 0x04},
};

static const u32 rad_bus_formats[] = {
	MEDIA_BUS_FMT_RGB888_1X24,
	MEDIA_BUS_FMT_RGB666_1X18,
	MEDIA_BUS_FMT_RGB565_1X16,
};

static const u32 rad_bus_flags = DRM_BUS_FLAG_DE_LOW |
				 DRM_BUS_FLAG_PIXDATA_NEGEDGE;

struct rad_panel {
	struct drm_panel panel;
	struct mipi_dsi_device *dsi;

	struct gpio_desc *reset;
	struct backlight_device *backlight;

	struct regulator_bulk_data *supplies;
	unsigned int num_supplies;

	bool prepared;
	bool enabled;
};

static const struct drm_display_mode default_mode = {
	.clock = 132000,
	.hdisplay = 1080,
	.hsync_start = 1080 + 20,
	.hsync_end = 1080 + 20 + 2,
	.htotal = 1080 + 20 + 2 + 34,
	.vdisplay = 1920,
	.vsync_start = 1920 + 10,
	.vsync_end = 1920 + 10 + 2,
	.vtotal = 1920 + 10 + 2 + 4,
	.vrefresh = 60,
	.width_mm = 68,
	.height_mm = 121,
	.flags = DRM_MODE_FLAG_NHSYNC |
		 DRM_MODE_FLAG_NVSYNC,
};

static inline struct rad_panel *to_rad_panel(struct drm_panel *panel)
{
	return container_of(panel, struct rad_panel, panel);
}

static int rad_panel_push_cmd_list(struct mipi_dsi_device *dsi)
{
	size_t i;
	size_t count = ARRAY_SIZE(manufacturer_cmd_set);
	int ret = 0;

	for (i = 0; i < count; i++) {
		const struct cmd_set_entry *entry = &manufacturer_cmd_set[i];
		u8 buffer[2] = { entry->cmd, entry->param };

		ret = mipi_dsi_generic_write(dsi, &buffer, sizeof(buffer));
		if (ret < 0)
			return ret;
	}

	return ret;
};

static int color_format_from_dsi_format(enum mipi_dsi_pixel_format format)
{
	switch (format) {
	case MIPI_DSI_FMT_RGB565:
		return COL_FMT_16BPP;
	case MIPI_DSI_FMT_RGB666:
	case MIPI_DSI_FMT_RGB666_PACKED:
		return COL_FMT_18BPP;
	case MIPI_DSI_FMT_RGB888:
		return COL_FMT_24BPP;
	default:
		return COL_FMT_24BPP; /* for backward compatibility */
	}
};

static int rad_panel_prepare(struct drm_panel *panel)
{
	struct rad_panel *rad = to_rad_panel(panel);
	int ret;

	if (rad->prepared)
		return 0;

	ret = regulator_bulk_enable(rad->num_supplies, rad->supplies);
	if (ret)
		return ret;

	if (rad->reset) {
		gpiod_set_value_cansleep(rad->reset, 1);
		usleep_range(3000, 5000);
		gpiod_set_value_cansleep(rad->reset, 0);
		usleep_range(18000, 20000);
	}

	rad->prepared = true;

	return 0;
}

static int rad_panel_unprepare(struct drm_panel *panel)
{
	struct rad_panel *rad = to_rad_panel(panel);
	int ret;

	if (!rad->prepared)
		return 0;

	/*
	 * Right after asserting the reset, we need to release it, so that the
	 * touch driver can have an active connection with the touch controller
	 * even after the display is turned off.
	 */
	if (rad->reset) {
		gpiod_set_value_cansleep(rad->reset, 1);
		usleep_range(15000, 17000);
		gpiod_set_value_cansleep(rad->reset, 0);
	}

	ret = regulator_bulk_disable(rad->num_supplies, rad->supplies);
	if (ret)
		return ret;

	rad->prepared = false;

	return 0;
}

static int rad_panel_enable(struct drm_panel *panel)
{
	struct rad_panel *rad = to_rad_panel(panel);
	struct mipi_dsi_device *dsi = rad->dsi;
	struct device *dev = &dsi->dev;
	int color_format = color_format_from_dsi_format(dsi->format);
	int ret;

	if (rad->enabled)
		return 0;

	dsi->mode_flags |= MIPI_DSI_MODE_LPM;

	ret = rad_panel_push_cmd_list(dsi);
	if (ret < 0) {
		DRM_DEV_ERROR(dev, "Failed to send MCS (%d)\n", ret);
		goto fail;
	}

	/* Select User Command Set table (CMD1) */
	ret = mipi_dsi_generic_write(dsi, (u8[]){ WRMAUCCTR, 0x00 }, 2);
	if (ret < 0)
		goto fail;

	/* Software reset */
	ret = mipi_dsi_dcs_soft_reset(dsi);
	if (ret < 0) {
		DRM_DEV_ERROR(dev, "Failed to do Software Reset (%d)\n", ret);
		goto fail;
	}

	usleep_range(15000, 17000);

	/* Set DSI mode */
	ret = mipi_dsi_generic_write(dsi, (u8[]){ 0xC2, 0x0B }, 2);
	if (ret < 0) {
		DRM_DEV_ERROR(dev, "Failed to set DSI mode (%d)\n", ret);
		goto fail;
	}
	/* Set tear ON */
	ret = mipi_dsi_dcs_set_tear_on(dsi, MIPI_DSI_DCS_TEAR_MODE_VBLANK);
	if (ret < 0) {
		DRM_DEV_ERROR(dev, "Failed to set tear ON (%d)\n", ret);
		goto fail;
	}
	/* Set tear scanline */
	ret = mipi_dsi_dcs_set_tear_scanline(dsi, 0x380);
	if (ret < 0) {
		DRM_DEV_ERROR(dev, "Failed to set tear scanline (%d)\n", ret);
		goto fail;
	}
	/* Set pixel format */
	ret = mipi_dsi_dcs_set_pixel_format(dsi, color_format);
	DRM_DEV_DEBUG_DRIVER(dev, "Interface color format set to 0x%x\n",
			     color_format);
	if (ret < 0) {
		DRM_DEV_ERROR(dev, "Failed to set pixel format (%d)\n", ret);
		goto fail;
	}
	/* Exit sleep mode */
	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
	if (ret < 0) {
		DRM_DEV_ERROR(dev, "Failed to exit sleep mode (%d)\n", ret);
		goto fail;
	}

	usleep_range(5000, 7000);

	ret = mipi_dsi_dcs_set_display_on(dsi);
	if (ret < 0) {
		DRM_DEV_ERROR(dev, "Failed to set display ON (%d)\n", ret);
		goto fail;
	}

	backlight_enable(rad->backlight);

	rad->enabled = true;

	return 0;

fail:
	gpiod_set_value_cansleep(rad->reset, 1);

	return ret;
}

static int rad_panel_disable(struct drm_panel *panel)
{
	struct rad_panel *rad = to_rad_panel(panel);
	struct mipi_dsi_device *dsi = rad->dsi;
	struct device *dev = &dsi->dev;
	int ret;

	if (!rad->enabled)
		return 0;

	dsi->mode_flags |= MIPI_DSI_MODE_LPM;

	backlight_disable(rad->backlight);

	usleep_range(10000, 12000);

	ret = mipi_dsi_dcs_set_display_off(dsi);
	if (ret < 0) {
		DRM_DEV_ERROR(dev, "Failed to set display OFF (%d)\n", ret);
		return ret;
	}

	usleep_range(5000, 10000);

	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
	if (ret < 0) {
		DRM_DEV_ERROR(dev, "Failed to enter sleep mode (%d)\n", ret);
		return ret;
	}

	rad->enabled = false;

	return 0;
}

static int rad_panel_get_modes(struct drm_panel *panel)
{
	struct drm_connector *connector = panel->connector;
	struct drm_display_mode *mode;

	mode = drm_mode_duplicate(panel->drm, &default_mode);
	if (!mode) {
		DRM_DEV_ERROR(panel->dev, "failed to add mode %ux%ux@%u\n",
			      default_mode.hdisplay, default_mode.vdisplay,
			      default_mode.vrefresh);
		return -ENOMEM;
	}

	drm_mode_set_name(mode);
	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
	drm_mode_probed_add(panel->connector, mode);

	connector->display_info.width_mm = mode->width_mm;
	connector->display_info.height_mm = mode->height_mm;
	connector->display_info.bus_flags = rad_bus_flags;

	drm_display_info_set_bus_formats(&connector->display_info,
					 rad_bus_formats,
					 ARRAY_SIZE(rad_bus_formats));
	return 1;
}

static int rad_bl_get_brightness(struct backlight_device *bl)
{
	struct mipi_dsi_device *dsi = bl_get_data(bl);
	struct rad_panel *rad = mipi_dsi_get_drvdata(dsi);
	u16 brightness;
	int ret;

	if (!rad->prepared)
		return 0;

	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;

	ret = mipi_dsi_dcs_get_display_brightness(dsi, &brightness);
	if (ret < 0)
		return ret;

	bl->props.brightness = brightness;

	return brightness & 0xff;
}

static int rad_bl_update_status(struct backlight_device *bl)
{
	struct mipi_dsi_device *dsi = bl_get_data(bl);
	struct rad_panel *rad = mipi_dsi_get_drvdata(dsi);
	int ret = 0;

	if (!rad->prepared)
		return 0;

	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;

	ret = mipi_dsi_dcs_set_display_brightness(dsi, bl->props.brightness);
	if (ret < 0)
		return ret;

	return 0;
}

static const struct backlight_ops rad_bl_ops = {
	.update_status = rad_bl_update_status,
	.get_brightness = rad_bl_get_brightness,
};

static const struct drm_panel_funcs rad_panel_funcs = {
	.prepare = rad_panel_prepare,
	.unprepare = rad_panel_unprepare,
	.enable = rad_panel_enable,
	.disable = rad_panel_disable,
	.get_modes = rad_panel_get_modes,
};

static const char * const rad_supply_names[] = {
	"v3p3",
	"v1p8",
};

static int rad_init_regulators(struct rad_panel *rad)
{
	struct device *dev = &rad->dsi->dev;
	int i;

	rad->num_supplies = ARRAY_SIZE(rad_supply_names);
	rad->supplies = devm_kcalloc(dev, rad->num_supplies,
				     sizeof(*rad->supplies), GFP_KERNEL);
	if (!rad->supplies)
		return -ENOMEM;

	for (i = 0; i < rad->num_supplies; i++)
		rad->supplies[i].supply = rad_supply_names[i];

	return devm_regulator_bulk_get(dev, rad->num_supplies, rad->supplies);
};

static int rad_panel_probe(struct mipi_dsi_device *dsi)
{
	struct device *dev = &dsi->dev;
	struct device_node *np = dev->of_node;
	struct rad_panel *panel;
	struct backlight_properties bl_props;
	int ret;
	u32 video_mode;

	panel = devm_kzalloc(&dsi->dev, sizeof(*panel), GFP_KERNEL);
	if (!panel)
		return -ENOMEM;

	mipi_dsi_set_drvdata(dsi, panel);

	panel->dsi = dsi;

	dsi->format = MIPI_DSI_FMT_RGB888;
	dsi->mode_flags =  MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO |
			   MIPI_DSI_CLOCK_NON_CONTINUOUS;

	ret = of_property_read_u32(np, "video-mode", &video_mode);
	if (!ret) {
		switch (video_mode) {
		case 0:
			/* burst mode */
			dsi->mode_flags |= MIPI_DSI_MODE_VIDEO_BURST;
			break;
		case 1:
			/* non-burst mode with sync event */
			break;
		case 2:
			/* non-burst mode with sync pulse */
			dsi->mode_flags |= MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
			break;
		default:
			dev_warn(dev, "invalid video mode %d\n", video_mode);
			break;
		}
	}

	ret = of_property_read_u32(np, "dsi-lanes", &dsi->lanes);
	if (ret) {
		dev_err(dev, "Failed to get dsi-lanes property (%d)\n", ret);
		return ret;
	}

	panel->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
	if (IS_ERR(panel->reset))
		return PTR_ERR(panel->reset);

	memset(&bl_props, 0, sizeof(bl_props));
	bl_props.type = BACKLIGHT_RAW;
	bl_props.brightness = 255;
	bl_props.max_brightness = 255;

	panel->backlight = devm_backlight_device_register(dev, dev_name(dev),
							  dev, dsi, &rad_bl_ops,
							  &bl_props);
	if (IS_ERR(panel->backlight)) {
		ret = PTR_ERR(panel->backlight);
		dev_err(dev, "Failed to register backlight (%d)\n", ret);
		return ret;
	}

	ret = rad_init_regulators(panel);
	if (ret)
		return ret;

	drm_panel_init(&panel->panel);
	panel->panel.funcs = &rad_panel_funcs;
	panel->panel.dev = dev;
	dev_set_drvdata(dev, panel);

	ret = drm_panel_add(&panel->panel);
	if (ret)
		return ret;

	ret = mipi_dsi_attach(dsi);
	if (ret)
		drm_panel_remove(&panel->panel);

	return ret;
}

static int rad_panel_remove(struct mipi_dsi_device *dsi)
{
	struct rad_panel *rad = mipi_dsi_get_drvdata(dsi);
	struct device *dev = &dsi->dev;
	int ret;

	ret = mipi_dsi_detach(dsi);
	if (ret)
		DRM_DEV_ERROR(dev, "Failed to detach from host (%d)\n",
			      ret);

	drm_panel_remove(&rad->panel);

	return 0;
}

static void rad_panel_shutdown(struct mipi_dsi_device *dsi)
{
	struct rad_panel *rad = mipi_dsi_get_drvdata(dsi);

	rad_panel_disable(&rad->panel);
	rad_panel_unprepare(&rad->panel);
}

static const struct of_device_id rad_of_match[] = {
	{ .compatible = "raydium,rm67191", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rad_of_match);

static struct mipi_dsi_driver rad_panel_driver = {
	.driver = {
		.name = "panel-raydium-rm67191",
		.of_match_table = rad_of_match,
	},
	.probe = rad_panel_probe,
	.remove = rad_panel_remove,
	.shutdown = rad_panel_shutdown,
};
module_mipi_dsi_driver(rad_panel_driver);

MODULE_AUTHOR("Robert Chiras <robert.chiras@nxp.com>");
MODULE_DESCRIPTION("DRM Driver for Raydium RM67191 MIPI DSI panel");
MODULE_LICENSE("GPL v2");