xref: /openbmc/linux/drivers/gpu/drm/vc4/vc4_hvs.c (revision 1edd0337)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2015 Broadcom
4  */
5 
6 /**
7  * DOC: VC4 HVS module.
8  *
9  * The Hardware Video Scaler (HVS) is the piece of hardware that does
10  * translation, scaling, colorspace conversion, and compositing of
11  * pixels stored in framebuffers into a FIFO of pixels going out to
12  * the Pixel Valve (CRTC).  It operates at the system clock rate (the
13  * system audio clock gate, specifically), which is much higher than
14  * the pixel clock rate.
15  *
16  * There is a single global HVS, with multiple output FIFOs that can
17  * be consumed by the PVs.  This file just manages the resources for
18  * the HVS, while the vc4_crtc.c code actually drives HVS setup for
19  * each CRTC.
20  */
21 
22 #include <linux/bitfield.h>
23 #include <linux/clk.h>
24 #include <linux/component.h>
25 #include <linux/platform_device.h>
26 
27 #include <drm/drm_atomic_helper.h>
28 #include <drm/drm_drv.h>
29 #include <drm/drm_vblank.h>
30 
31 #include <soc/bcm2835/raspberrypi-firmware.h>
32 
33 #include "vc4_drv.h"
34 #include "vc4_regs.h"
35 
36 static const struct debugfs_reg32 hvs_regs[] = {
37 	VC4_REG32(SCALER_DISPCTRL),
38 	VC4_REG32(SCALER_DISPSTAT),
39 	VC4_REG32(SCALER_DISPID),
40 	VC4_REG32(SCALER_DISPECTRL),
41 	VC4_REG32(SCALER_DISPPROF),
42 	VC4_REG32(SCALER_DISPDITHER),
43 	VC4_REG32(SCALER_DISPEOLN),
44 	VC4_REG32(SCALER_DISPLIST0),
45 	VC4_REG32(SCALER_DISPLIST1),
46 	VC4_REG32(SCALER_DISPLIST2),
47 	VC4_REG32(SCALER_DISPLSTAT),
48 	VC4_REG32(SCALER_DISPLACT0),
49 	VC4_REG32(SCALER_DISPLACT1),
50 	VC4_REG32(SCALER_DISPLACT2),
51 	VC4_REG32(SCALER_DISPCTRL0),
52 	VC4_REG32(SCALER_DISPBKGND0),
53 	VC4_REG32(SCALER_DISPSTAT0),
54 	VC4_REG32(SCALER_DISPBASE0),
55 	VC4_REG32(SCALER_DISPCTRL1),
56 	VC4_REG32(SCALER_DISPBKGND1),
57 	VC4_REG32(SCALER_DISPSTAT1),
58 	VC4_REG32(SCALER_DISPBASE1),
59 	VC4_REG32(SCALER_DISPCTRL2),
60 	VC4_REG32(SCALER_DISPBKGND2),
61 	VC4_REG32(SCALER_DISPSTAT2),
62 	VC4_REG32(SCALER_DISPBASE2),
63 	VC4_REG32(SCALER_DISPALPHA2),
64 	VC4_REG32(SCALER_OLEDOFFS),
65 	VC4_REG32(SCALER_OLEDCOEF0),
66 	VC4_REG32(SCALER_OLEDCOEF1),
67 	VC4_REG32(SCALER_OLEDCOEF2),
68 };
69 
70 void vc4_hvs_dump_state(struct vc4_hvs *hvs)
71 {
72 	struct drm_device *drm = &hvs->vc4->base;
73 	struct drm_printer p = drm_info_printer(&hvs->pdev->dev);
74 	int idx, i;
75 
76 	if (!drm_dev_enter(drm, &idx))
77 		return;
78 
79 	drm_print_regset32(&p, &hvs->regset);
80 
81 	DRM_INFO("HVS ctx:\n");
82 	for (i = 0; i < 64; i += 4) {
83 		DRM_INFO("0x%08x (%s): 0x%08x 0x%08x 0x%08x 0x%08x\n",
84 			 i * 4, i < HVS_BOOTLOADER_DLIST_END ? "B" : "D",
85 			 readl((u32 __iomem *)hvs->dlist + i + 0),
86 			 readl((u32 __iomem *)hvs->dlist + i + 1),
87 			 readl((u32 __iomem *)hvs->dlist + i + 2),
88 			 readl((u32 __iomem *)hvs->dlist + i + 3));
89 	}
90 
91 	drm_dev_exit(idx);
92 }
93 
94 static int vc4_hvs_debugfs_underrun(struct seq_file *m, void *data)
95 {
96 	struct drm_debugfs_entry *entry = m->private;
97 	struct drm_device *dev = entry->dev;
98 	struct vc4_dev *vc4 = to_vc4_dev(dev);
99 	struct drm_printer p = drm_seq_file_printer(m);
100 
101 	drm_printf(&p, "%d\n", atomic_read(&vc4->underrun));
102 
103 	return 0;
104 }
105 
106 static int vc4_hvs_debugfs_dlist(struct seq_file *m, void *data)
107 {
108 	struct drm_debugfs_entry *entry = m->private;
109 	struct drm_device *dev = entry->dev;
110 	struct vc4_dev *vc4 = to_vc4_dev(dev);
111 	struct vc4_hvs *hvs = vc4->hvs;
112 	struct drm_printer p = drm_seq_file_printer(m);
113 	unsigned int next_entry_start = 0;
114 	unsigned int i, j;
115 	u32 dlist_word, dispstat;
116 
117 	for (i = 0; i < SCALER_CHANNELS_COUNT; i++) {
118 		dispstat = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTATX(i)),
119 					 SCALER_DISPSTATX_MODE);
120 		if (dispstat == SCALER_DISPSTATX_MODE_DISABLED ||
121 		    dispstat == SCALER_DISPSTATX_MODE_EOF) {
122 			drm_printf(&p, "HVS chan %u disabled\n", i);
123 			continue;
124 		}
125 
126 		drm_printf(&p, "HVS chan %u:\n", i);
127 
128 		for (j = HVS_READ(SCALER_DISPLISTX(i)); j < 256; j++) {
129 			dlist_word = readl((u32 __iomem *)vc4->hvs->dlist + j);
130 			drm_printf(&p, "dlist: %02d: 0x%08x\n", j,
131 				   dlist_word);
132 			if (!next_entry_start ||
133 			    next_entry_start == j) {
134 				if (dlist_word & SCALER_CTL0_END)
135 					break;
136 				next_entry_start = j +
137 					VC4_GET_FIELD(dlist_word,
138 						      SCALER_CTL0_SIZE);
139 			}
140 		}
141 	}
142 
143 	return 0;
144 }
145 
146 /* The filter kernel is composed of dwords each containing 3 9-bit
147  * signed integers packed next to each other.
148  */
149 #define VC4_INT_TO_COEFF(coeff) (coeff & 0x1ff)
150 #define VC4_PPF_FILTER_WORD(c0, c1, c2)				\
151 	((((c0) & 0x1ff) << 0) |				\
152 	 (((c1) & 0x1ff) << 9) |				\
153 	 (((c2) & 0x1ff) << 18))
154 
155 /* The whole filter kernel is arranged as the coefficients 0-16 going
156  * up, then a pad, then 17-31 going down and reversed within the
157  * dwords.  This means that a linear phase kernel (where it's
158  * symmetrical at the boundary between 15 and 16) has the last 5
159  * dwords matching the first 5, but reversed.
160  */
161 #define VC4_LINEAR_PHASE_KERNEL(c0, c1, c2, c3, c4, c5, c6, c7, c8,	\
162 				c9, c10, c11, c12, c13, c14, c15)	\
163 	{VC4_PPF_FILTER_WORD(c0, c1, c2),				\
164 	 VC4_PPF_FILTER_WORD(c3, c4, c5),				\
165 	 VC4_PPF_FILTER_WORD(c6, c7, c8),				\
166 	 VC4_PPF_FILTER_WORD(c9, c10, c11),				\
167 	 VC4_PPF_FILTER_WORD(c12, c13, c14),				\
168 	 VC4_PPF_FILTER_WORD(c15, c15, 0)}
169 
170 #define VC4_LINEAR_PHASE_KERNEL_DWORDS 6
171 #define VC4_KERNEL_DWORDS (VC4_LINEAR_PHASE_KERNEL_DWORDS * 2 - 1)
172 
173 /* Recommended B=1/3, C=1/3 filter choice from Mitchell/Netravali.
174  * http://www.cs.utexas.edu/~fussell/courses/cs384g/lectures/mitchell/Mitchell.pdf
175  */
176 static const u32 mitchell_netravali_1_3_1_3_kernel[] =
177 	VC4_LINEAR_PHASE_KERNEL(0, -2, -6, -8, -10, -8, -3, 2, 18,
178 				50, 82, 119, 155, 187, 213, 227);
179 
180 static int vc4_hvs_upload_linear_kernel(struct vc4_hvs *hvs,
181 					struct drm_mm_node *space,
182 					const u32 *kernel)
183 {
184 	int ret, i;
185 	u32 __iomem *dst_kernel;
186 
187 	/*
188 	 * NOTE: We don't need a call to drm_dev_enter()/drm_dev_exit()
189 	 * here since that function is only called from vc4_hvs_bind().
190 	 */
191 
192 	ret = drm_mm_insert_node(&hvs->dlist_mm, space, VC4_KERNEL_DWORDS);
193 	if (ret) {
194 		DRM_ERROR("Failed to allocate space for filter kernel: %d\n",
195 			  ret);
196 		return ret;
197 	}
198 
199 	dst_kernel = hvs->dlist + space->start;
200 
201 	for (i = 0; i < VC4_KERNEL_DWORDS; i++) {
202 		if (i < VC4_LINEAR_PHASE_KERNEL_DWORDS)
203 			writel(kernel[i], &dst_kernel[i]);
204 		else {
205 			writel(kernel[VC4_KERNEL_DWORDS - i - 1],
206 			       &dst_kernel[i]);
207 		}
208 	}
209 
210 	return 0;
211 }
212 
213 static void vc4_hvs_lut_load(struct vc4_hvs *hvs,
214 			     struct vc4_crtc *vc4_crtc)
215 {
216 	struct drm_device *drm = &hvs->vc4->base;
217 	struct drm_crtc *crtc = &vc4_crtc->base;
218 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
219 	int idx;
220 	u32 i;
221 
222 	if (!drm_dev_enter(drm, &idx))
223 		return;
224 
225 	/* The LUT memory is laid out with each HVS channel in order,
226 	 * each of which takes 256 writes for R, 256 for G, then 256
227 	 * for B.
228 	 */
229 	HVS_WRITE(SCALER_GAMADDR,
230 		  SCALER_GAMADDR_AUTOINC |
231 		  (vc4_state->assigned_channel * 3 * crtc->gamma_size));
232 
233 	for (i = 0; i < crtc->gamma_size; i++)
234 		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_r[i]);
235 	for (i = 0; i < crtc->gamma_size; i++)
236 		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_g[i]);
237 	for (i = 0; i < crtc->gamma_size; i++)
238 		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_b[i]);
239 
240 	drm_dev_exit(idx);
241 }
242 
243 static void vc4_hvs_update_gamma_lut(struct vc4_hvs *hvs,
244 				     struct vc4_crtc *vc4_crtc)
245 {
246 	struct drm_crtc_state *crtc_state = vc4_crtc->base.state;
247 	struct drm_color_lut *lut = crtc_state->gamma_lut->data;
248 	u32 length = drm_color_lut_size(crtc_state->gamma_lut);
249 	u32 i;
250 
251 	for (i = 0; i < length; i++) {
252 		vc4_crtc->lut_r[i] = drm_color_lut_extract(lut[i].red, 8);
253 		vc4_crtc->lut_g[i] = drm_color_lut_extract(lut[i].green, 8);
254 		vc4_crtc->lut_b[i] = drm_color_lut_extract(lut[i].blue, 8);
255 	}
256 
257 	vc4_hvs_lut_load(hvs, vc4_crtc);
258 }
259 
260 u8 vc4_hvs_get_fifo_frame_count(struct vc4_hvs *hvs, unsigned int fifo)
261 {
262 	struct drm_device *drm = &hvs->vc4->base;
263 	u8 field = 0;
264 	int idx;
265 
266 	if (!drm_dev_enter(drm, &idx))
267 		return 0;
268 
269 	switch (fifo) {
270 	case 0:
271 		field = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTAT1),
272 				      SCALER_DISPSTAT1_FRCNT0);
273 		break;
274 	case 1:
275 		field = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTAT1),
276 				      SCALER_DISPSTAT1_FRCNT1);
277 		break;
278 	case 2:
279 		field = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTAT2),
280 				      SCALER_DISPSTAT2_FRCNT2);
281 		break;
282 	}
283 
284 	drm_dev_exit(idx);
285 	return field;
286 }
287 
288 int vc4_hvs_get_fifo_from_output(struct vc4_hvs *hvs, unsigned int output)
289 {
290 	struct vc4_dev *vc4 = hvs->vc4;
291 	u32 reg;
292 	int ret;
293 
294 	if (!vc4->is_vc5)
295 		return output;
296 
297 	/*
298 	 * NOTE: We should probably use drm_dev_enter()/drm_dev_exit()
299 	 * here, but this function is only used during the DRM device
300 	 * initialization, so we should be fine.
301 	 */
302 
303 	switch (output) {
304 	case 0:
305 		return 0;
306 
307 	case 1:
308 		return 1;
309 
310 	case 2:
311 		reg = HVS_READ(SCALER_DISPECTRL);
312 		ret = FIELD_GET(SCALER_DISPECTRL_DSP2_MUX_MASK, reg);
313 		if (ret == 0)
314 			return 2;
315 
316 		return 0;
317 
318 	case 3:
319 		reg = HVS_READ(SCALER_DISPCTRL);
320 		ret = FIELD_GET(SCALER_DISPCTRL_DSP3_MUX_MASK, reg);
321 		if (ret == 3)
322 			return -EPIPE;
323 
324 		return ret;
325 
326 	case 4:
327 		reg = HVS_READ(SCALER_DISPEOLN);
328 		ret = FIELD_GET(SCALER_DISPEOLN_DSP4_MUX_MASK, reg);
329 		if (ret == 3)
330 			return -EPIPE;
331 
332 		return ret;
333 
334 	case 5:
335 		reg = HVS_READ(SCALER_DISPDITHER);
336 		ret = FIELD_GET(SCALER_DISPDITHER_DSP5_MUX_MASK, reg);
337 		if (ret == 3)
338 			return -EPIPE;
339 
340 		return ret;
341 
342 	default:
343 		return -EPIPE;
344 	}
345 }
346 
347 static int vc4_hvs_init_channel(struct vc4_hvs *hvs, struct drm_crtc *crtc,
348 				struct drm_display_mode *mode, bool oneshot)
349 {
350 	struct vc4_dev *vc4 = hvs->vc4;
351 	struct drm_device *drm = &vc4->base;
352 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
353 	struct vc4_crtc_state *vc4_crtc_state = to_vc4_crtc_state(crtc->state);
354 	unsigned int chan = vc4_crtc_state->assigned_channel;
355 	bool interlace = mode->flags & DRM_MODE_FLAG_INTERLACE;
356 	u32 dispbkgndx;
357 	u32 dispctrl;
358 	int idx;
359 
360 	if (!drm_dev_enter(drm, &idx))
361 		return -ENODEV;
362 
363 	HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
364 	HVS_WRITE(SCALER_DISPCTRLX(chan), SCALER_DISPCTRLX_RESET);
365 	HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
366 
367 	/* Turn on the scaler, which will wait for vstart to start
368 	 * compositing.
369 	 * When feeding the transposer, we should operate in oneshot
370 	 * mode.
371 	 */
372 	dispctrl = SCALER_DISPCTRLX_ENABLE;
373 	dispbkgndx = HVS_READ(SCALER_DISPBKGNDX(chan));
374 
375 	if (!vc4->is_vc5) {
376 		dispctrl |= VC4_SET_FIELD(mode->hdisplay,
377 					  SCALER_DISPCTRLX_WIDTH) |
378 			    VC4_SET_FIELD(mode->vdisplay,
379 					  SCALER_DISPCTRLX_HEIGHT) |
380 			    (oneshot ? SCALER_DISPCTRLX_ONESHOT : 0);
381 		dispbkgndx |= SCALER_DISPBKGND_AUTOHS;
382 	} else {
383 		dispctrl |= VC4_SET_FIELD(mode->hdisplay,
384 					  SCALER5_DISPCTRLX_WIDTH) |
385 			    VC4_SET_FIELD(mode->vdisplay,
386 					  SCALER5_DISPCTRLX_HEIGHT) |
387 			    (oneshot ? SCALER5_DISPCTRLX_ONESHOT : 0);
388 		dispbkgndx &= ~SCALER5_DISPBKGND_BCK2BCK;
389 	}
390 
391 	HVS_WRITE(SCALER_DISPCTRLX(chan), dispctrl);
392 
393 	dispbkgndx &= ~SCALER_DISPBKGND_GAMMA;
394 	dispbkgndx &= ~SCALER_DISPBKGND_INTERLACE;
395 
396 	HVS_WRITE(SCALER_DISPBKGNDX(chan), dispbkgndx |
397 		  ((!vc4->is_vc5) ? SCALER_DISPBKGND_GAMMA : 0) |
398 		  (interlace ? SCALER_DISPBKGND_INTERLACE : 0));
399 
400 	/* Reload the LUT, since the SRAMs would have been disabled if
401 	 * all CRTCs had SCALER_DISPBKGND_GAMMA unset at once.
402 	 */
403 	vc4_hvs_lut_load(hvs, vc4_crtc);
404 
405 	drm_dev_exit(idx);
406 
407 	return 0;
408 }
409 
410 void vc4_hvs_stop_channel(struct vc4_hvs *hvs, unsigned int chan)
411 {
412 	struct drm_device *drm = &hvs->vc4->base;
413 	int idx;
414 
415 	if (!drm_dev_enter(drm, &idx))
416 		return;
417 
418 	if (HVS_READ(SCALER_DISPCTRLX(chan)) & SCALER_DISPCTRLX_ENABLE)
419 		goto out;
420 
421 	HVS_WRITE(SCALER_DISPCTRLX(chan),
422 		  HVS_READ(SCALER_DISPCTRLX(chan)) | SCALER_DISPCTRLX_RESET);
423 	HVS_WRITE(SCALER_DISPCTRLX(chan),
424 		  HVS_READ(SCALER_DISPCTRLX(chan)) & ~SCALER_DISPCTRLX_ENABLE);
425 
426 	/* Once we leave, the scaler should be disabled and its fifo empty. */
427 	WARN_ON_ONCE(HVS_READ(SCALER_DISPCTRLX(chan)) & SCALER_DISPCTRLX_RESET);
428 
429 	WARN_ON_ONCE(VC4_GET_FIELD(HVS_READ(SCALER_DISPSTATX(chan)),
430 				   SCALER_DISPSTATX_MODE) !=
431 		     SCALER_DISPSTATX_MODE_DISABLED);
432 
433 	WARN_ON_ONCE((HVS_READ(SCALER_DISPSTATX(chan)) &
434 		      (SCALER_DISPSTATX_FULL | SCALER_DISPSTATX_EMPTY)) !=
435 		     SCALER_DISPSTATX_EMPTY);
436 
437 out:
438 	drm_dev_exit(idx);
439 }
440 
441 int vc4_hvs_atomic_check(struct drm_crtc *crtc, struct drm_atomic_state *state)
442 {
443 	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
444 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc_state);
445 	struct drm_device *dev = crtc->dev;
446 	struct vc4_dev *vc4 = to_vc4_dev(dev);
447 	struct drm_plane *plane;
448 	unsigned long flags;
449 	const struct drm_plane_state *plane_state;
450 	u32 dlist_count = 0;
451 	int ret;
452 
453 	/* The pixelvalve can only feed one encoder (and encoders are
454 	 * 1:1 with connectors.)
455 	 */
456 	if (hweight32(crtc_state->connector_mask) > 1)
457 		return -EINVAL;
458 
459 	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, crtc_state)
460 		dlist_count += vc4_plane_dlist_size(plane_state);
461 
462 	dlist_count++; /* Account for SCALER_CTL0_END. */
463 
464 	spin_lock_irqsave(&vc4->hvs->mm_lock, flags);
465 	ret = drm_mm_insert_node(&vc4->hvs->dlist_mm, &vc4_state->mm,
466 				 dlist_count);
467 	spin_unlock_irqrestore(&vc4->hvs->mm_lock, flags);
468 	if (ret)
469 		return ret;
470 
471 	return 0;
472 }
473 
474 static void vc4_hvs_install_dlist(struct drm_crtc *crtc)
475 {
476 	struct drm_device *dev = crtc->dev;
477 	struct vc4_dev *vc4 = to_vc4_dev(dev);
478 	struct vc4_hvs *hvs = vc4->hvs;
479 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
480 	int idx;
481 
482 	if (!drm_dev_enter(dev, &idx))
483 		return;
484 
485 	HVS_WRITE(SCALER_DISPLISTX(vc4_state->assigned_channel),
486 		  vc4_state->mm.start);
487 
488 	drm_dev_exit(idx);
489 }
490 
491 static void vc4_hvs_update_dlist(struct drm_crtc *crtc)
492 {
493 	struct drm_device *dev = crtc->dev;
494 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
495 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
496 	unsigned long flags;
497 
498 	if (crtc->state->event) {
499 		crtc->state->event->pipe = drm_crtc_index(crtc);
500 
501 		WARN_ON(drm_crtc_vblank_get(crtc) != 0);
502 
503 		spin_lock_irqsave(&dev->event_lock, flags);
504 
505 		if (!vc4_crtc->feeds_txp || vc4_state->txp_armed) {
506 			vc4_crtc->event = crtc->state->event;
507 			crtc->state->event = NULL;
508 		}
509 
510 		spin_unlock_irqrestore(&dev->event_lock, flags);
511 	}
512 
513 	spin_lock_irqsave(&vc4_crtc->irq_lock, flags);
514 	vc4_crtc->current_dlist = vc4_state->mm.start;
515 	spin_unlock_irqrestore(&vc4_crtc->irq_lock, flags);
516 }
517 
518 void vc4_hvs_atomic_begin(struct drm_crtc *crtc,
519 			  struct drm_atomic_state *state)
520 {
521 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
522 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
523 	unsigned long flags;
524 
525 	spin_lock_irqsave(&vc4_crtc->irq_lock, flags);
526 	vc4_crtc->current_hvs_channel = vc4_state->assigned_channel;
527 	spin_unlock_irqrestore(&vc4_crtc->irq_lock, flags);
528 }
529 
530 void vc4_hvs_atomic_enable(struct drm_crtc *crtc,
531 			   struct drm_atomic_state *state)
532 {
533 	struct drm_device *dev = crtc->dev;
534 	struct vc4_dev *vc4 = to_vc4_dev(dev);
535 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
536 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
537 	bool oneshot = vc4_crtc->feeds_txp;
538 
539 	vc4_hvs_install_dlist(crtc);
540 	vc4_hvs_update_dlist(crtc);
541 	vc4_hvs_init_channel(vc4->hvs, crtc, mode, oneshot);
542 }
543 
544 void vc4_hvs_atomic_disable(struct drm_crtc *crtc,
545 			    struct drm_atomic_state *state)
546 {
547 	struct drm_device *dev = crtc->dev;
548 	struct vc4_dev *vc4 = to_vc4_dev(dev);
549 	struct drm_crtc_state *old_state = drm_atomic_get_old_crtc_state(state, crtc);
550 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(old_state);
551 	unsigned int chan = vc4_state->assigned_channel;
552 
553 	vc4_hvs_stop_channel(vc4->hvs, chan);
554 }
555 
556 void vc4_hvs_atomic_flush(struct drm_crtc *crtc,
557 			  struct drm_atomic_state *state)
558 {
559 	struct drm_crtc_state *old_state = drm_atomic_get_old_crtc_state(state,
560 									 crtc);
561 	struct drm_device *dev = crtc->dev;
562 	struct vc4_dev *vc4 = to_vc4_dev(dev);
563 	struct vc4_hvs *hvs = vc4->hvs;
564 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
565 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
566 	unsigned int channel = vc4_state->assigned_channel;
567 	struct drm_plane *plane;
568 	struct vc4_plane_state *vc4_plane_state;
569 	bool debug_dump_regs = false;
570 	bool enable_bg_fill = false;
571 	u32 __iomem *dlist_start = vc4->hvs->dlist + vc4_state->mm.start;
572 	u32 __iomem *dlist_next = dlist_start;
573 	unsigned int zpos = 0;
574 	bool found = false;
575 	int idx;
576 
577 	if (!drm_dev_enter(dev, &idx)) {
578 		vc4_crtc_send_vblank(crtc);
579 		return;
580 	}
581 
582 	if (vc4_state->assigned_channel == VC4_HVS_CHANNEL_DISABLED)
583 		return;
584 
585 	if (debug_dump_regs) {
586 		DRM_INFO("CRTC %d HVS before:\n", drm_crtc_index(crtc));
587 		vc4_hvs_dump_state(hvs);
588 	}
589 
590 	/* Copy all the active planes' dlist contents to the hardware dlist. */
591 	do {
592 		found = false;
593 
594 		drm_atomic_crtc_for_each_plane(plane, crtc) {
595 			if (plane->state->normalized_zpos != zpos)
596 				continue;
597 
598 			/* Is this the first active plane? */
599 			if (dlist_next == dlist_start) {
600 				/* We need to enable background fill when a plane
601 				 * could be alpha blending from the background, i.e.
602 				 * where no other plane is underneath. It suffices to
603 				 * consider the first active plane here since we set
604 				 * needs_bg_fill such that either the first plane
605 				 * already needs it or all planes on top blend from
606 				 * the first or a lower plane.
607 				 */
608 				vc4_plane_state = to_vc4_plane_state(plane->state);
609 				enable_bg_fill = vc4_plane_state->needs_bg_fill;
610 			}
611 
612 			dlist_next += vc4_plane_write_dlist(plane, dlist_next);
613 
614 			found = true;
615 		}
616 
617 		zpos++;
618 	} while (found);
619 
620 	writel(SCALER_CTL0_END, dlist_next);
621 	dlist_next++;
622 
623 	WARN_ON_ONCE(dlist_next - dlist_start != vc4_state->mm.size);
624 
625 	if (enable_bg_fill)
626 		/* This sets a black background color fill, as is the case
627 		 * with other DRM drivers.
628 		 */
629 		HVS_WRITE(SCALER_DISPBKGNDX(channel),
630 			  HVS_READ(SCALER_DISPBKGNDX(channel)) |
631 			  SCALER_DISPBKGND_FILL);
632 
633 	/* Only update DISPLIST if the CRTC was already running and is not
634 	 * being disabled.
635 	 * vc4_crtc_enable() takes care of updating the dlist just after
636 	 * re-enabling VBLANK interrupts and before enabling the engine.
637 	 * If the CRTC is being disabled, there's no point in updating this
638 	 * information.
639 	 */
640 	if (crtc->state->active && old_state->active) {
641 		vc4_hvs_install_dlist(crtc);
642 		vc4_hvs_update_dlist(crtc);
643 	}
644 
645 	if (crtc->state->color_mgmt_changed) {
646 		u32 dispbkgndx = HVS_READ(SCALER_DISPBKGNDX(channel));
647 
648 		if (crtc->state->gamma_lut) {
649 			vc4_hvs_update_gamma_lut(hvs, vc4_crtc);
650 			dispbkgndx |= SCALER_DISPBKGND_GAMMA;
651 		} else {
652 			/* Unsetting DISPBKGND_GAMMA skips the gamma lut step
653 			 * in hardware, which is the same as a linear lut that
654 			 * DRM expects us to use in absence of a user lut.
655 			 */
656 			dispbkgndx &= ~SCALER_DISPBKGND_GAMMA;
657 		}
658 		HVS_WRITE(SCALER_DISPBKGNDX(channel), dispbkgndx);
659 	}
660 
661 	if (debug_dump_regs) {
662 		DRM_INFO("CRTC %d HVS after:\n", drm_crtc_index(crtc));
663 		vc4_hvs_dump_state(hvs);
664 	}
665 
666 	drm_dev_exit(idx);
667 }
668 
669 void vc4_hvs_mask_underrun(struct vc4_hvs *hvs, int channel)
670 {
671 	struct drm_device *drm = &hvs->vc4->base;
672 	u32 dispctrl;
673 	int idx;
674 
675 	if (!drm_dev_enter(drm, &idx))
676 		return;
677 
678 	dispctrl = HVS_READ(SCALER_DISPCTRL);
679 	dispctrl &= ~(hvs->vc4->is_vc5 ? SCALER5_DISPCTRL_DSPEISLUR(channel) :
680 					 SCALER_DISPCTRL_DSPEISLUR(channel));
681 
682 	HVS_WRITE(SCALER_DISPCTRL, dispctrl);
683 
684 	drm_dev_exit(idx);
685 }
686 
687 void vc4_hvs_unmask_underrun(struct vc4_hvs *hvs, int channel)
688 {
689 	struct drm_device *drm = &hvs->vc4->base;
690 	u32 dispctrl;
691 	int idx;
692 
693 	if (!drm_dev_enter(drm, &idx))
694 		return;
695 
696 	dispctrl = HVS_READ(SCALER_DISPCTRL);
697 	dispctrl |= (hvs->vc4->is_vc5 ? SCALER5_DISPCTRL_DSPEISLUR(channel) :
698 					SCALER_DISPCTRL_DSPEISLUR(channel));
699 
700 	HVS_WRITE(SCALER_DISPSTAT,
701 		  SCALER_DISPSTAT_EUFLOW(channel));
702 	HVS_WRITE(SCALER_DISPCTRL, dispctrl);
703 
704 	drm_dev_exit(idx);
705 }
706 
707 static void vc4_hvs_report_underrun(struct drm_device *dev)
708 {
709 	struct vc4_dev *vc4 = to_vc4_dev(dev);
710 
711 	atomic_inc(&vc4->underrun);
712 	DRM_DEV_ERROR(dev->dev, "HVS underrun\n");
713 }
714 
715 static irqreturn_t vc4_hvs_irq_handler(int irq, void *data)
716 {
717 	struct drm_device *dev = data;
718 	struct vc4_dev *vc4 = to_vc4_dev(dev);
719 	struct vc4_hvs *hvs = vc4->hvs;
720 	irqreturn_t irqret = IRQ_NONE;
721 	int channel;
722 	u32 control;
723 	u32 status;
724 	u32 dspeislur;
725 
726 	/*
727 	 * NOTE: We don't need to protect the register access using
728 	 * drm_dev_enter() there because the interrupt handler lifetime
729 	 * is tied to the device itself, and not to the DRM device.
730 	 *
731 	 * So when the device will be gone, one of the first thing we
732 	 * will be doing will be to unregister the interrupt handler,
733 	 * and then unregister the DRM device. drm_dev_enter() would
734 	 * thus always succeed if we are here.
735 	 */
736 
737 	status = HVS_READ(SCALER_DISPSTAT);
738 	control = HVS_READ(SCALER_DISPCTRL);
739 
740 	for (channel = 0; channel < SCALER_CHANNELS_COUNT; channel++) {
741 		dspeislur = vc4->is_vc5 ? SCALER5_DISPCTRL_DSPEISLUR(channel) :
742 					  SCALER_DISPCTRL_DSPEISLUR(channel);
743 		/* Interrupt masking is not always honored, so check it here. */
744 		if (status & SCALER_DISPSTAT_EUFLOW(channel) &&
745 		    control & dspeislur) {
746 			vc4_hvs_mask_underrun(hvs, channel);
747 			vc4_hvs_report_underrun(dev);
748 
749 			irqret = IRQ_HANDLED;
750 		}
751 	}
752 
753 	/* Clear every per-channel interrupt flag. */
754 	HVS_WRITE(SCALER_DISPSTAT, SCALER_DISPSTAT_IRQMASK(0) |
755 				   SCALER_DISPSTAT_IRQMASK(1) |
756 				   SCALER_DISPSTAT_IRQMASK(2));
757 
758 	return irqret;
759 }
760 
761 int vc4_hvs_debugfs_init(struct drm_minor *minor)
762 {
763 	struct drm_device *drm = minor->dev;
764 	struct vc4_dev *vc4 = to_vc4_dev(drm);
765 	struct vc4_hvs *hvs = vc4->hvs;
766 
767 	if (!vc4->hvs)
768 		return -ENODEV;
769 
770 	if (!vc4->is_vc5)
771 		debugfs_create_bool("hvs_load_tracker", S_IRUGO | S_IWUSR,
772 				    minor->debugfs_root,
773 				    &vc4->load_tracker_enabled);
774 
775 	drm_debugfs_add_file(drm, "hvs_dlists", vc4_hvs_debugfs_dlist, NULL);
776 
777 	drm_debugfs_add_file(drm, "hvs_underrun", vc4_hvs_debugfs_underrun, NULL);
778 
779 	vc4_debugfs_add_regset32(drm, "hvs_regs", &hvs->regset);
780 
781 	return 0;
782 }
783 
784 struct vc4_hvs *__vc4_hvs_alloc(struct vc4_dev *vc4, struct platform_device *pdev)
785 {
786 	struct drm_device *drm = &vc4->base;
787 	struct vc4_hvs *hvs;
788 
789 	hvs = drmm_kzalloc(drm, sizeof(*hvs), GFP_KERNEL);
790 	if (!hvs)
791 		return ERR_PTR(-ENOMEM);
792 
793 	hvs->vc4 = vc4;
794 	hvs->pdev = pdev;
795 
796 	spin_lock_init(&hvs->mm_lock);
797 
798 	/* Set up the HVS display list memory manager.  We never
799 	 * overwrite the setup from the bootloader (just 128b out of
800 	 * our 16K), since we don't want to scramble the screen when
801 	 * transitioning from the firmware's boot setup to runtime.
802 	 */
803 	drm_mm_init(&hvs->dlist_mm,
804 		    HVS_BOOTLOADER_DLIST_END,
805 		    (SCALER_DLIST_SIZE >> 2) - HVS_BOOTLOADER_DLIST_END);
806 
807 	/* Set up the HVS LBM memory manager.  We could have some more
808 	 * complicated data structure that allowed reuse of LBM areas
809 	 * between planes when they don't overlap on the screen, but
810 	 * for now we just allocate globally.
811 	 */
812 	if (!vc4->is_vc5)
813 		/* 48k words of 2x12-bit pixels */
814 		drm_mm_init(&hvs->lbm_mm, 0, 48 * 1024);
815 	else
816 		/* 60k words of 4x12-bit pixels */
817 		drm_mm_init(&hvs->lbm_mm, 0, 60 * 1024);
818 
819 	vc4->hvs = hvs;
820 
821 	return hvs;
822 }
823 
824 static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
825 {
826 	struct platform_device *pdev = to_platform_device(dev);
827 	struct drm_device *drm = dev_get_drvdata(master);
828 	struct vc4_dev *vc4 = to_vc4_dev(drm);
829 	struct vc4_hvs *hvs = NULL;
830 	int ret;
831 	u32 dispctrl;
832 	u32 reg, top;
833 
834 	hvs = __vc4_hvs_alloc(vc4, NULL);
835 	if (IS_ERR(hvs))
836 		return PTR_ERR(hvs);
837 
838 	hvs->regs = vc4_ioremap_regs(pdev, 0);
839 	if (IS_ERR(hvs->regs))
840 		return PTR_ERR(hvs->regs);
841 
842 	hvs->regset.base = hvs->regs;
843 	hvs->regset.regs = hvs_regs;
844 	hvs->regset.nregs = ARRAY_SIZE(hvs_regs);
845 
846 	if (vc4->is_vc5) {
847 		struct rpi_firmware *firmware;
848 		struct device_node *node;
849 		unsigned int max_rate;
850 
851 		node = rpi_firmware_find_node();
852 		if (!node)
853 			return -EINVAL;
854 
855 		firmware = rpi_firmware_get(node);
856 		of_node_put(node);
857 		if (!firmware)
858 			return -EPROBE_DEFER;
859 
860 		hvs->core_clk = devm_clk_get(&pdev->dev, NULL);
861 		if (IS_ERR(hvs->core_clk)) {
862 			dev_err(&pdev->dev, "Couldn't get core clock\n");
863 			return PTR_ERR(hvs->core_clk);
864 		}
865 
866 		max_rate = rpi_firmware_clk_get_max_rate(firmware,
867 							 RPI_FIRMWARE_CORE_CLK_ID);
868 		rpi_firmware_put(firmware);
869 		if (max_rate >= 550000000)
870 			hvs->vc5_hdmi_enable_hdmi_20 = true;
871 
872 		if (max_rate >= 600000000)
873 			hvs->vc5_hdmi_enable_4096by2160 = true;
874 
875 		hvs->max_core_rate = max_rate;
876 
877 		ret = clk_prepare_enable(hvs->core_clk);
878 		if (ret) {
879 			dev_err(&pdev->dev, "Couldn't enable the core clock\n");
880 			return ret;
881 		}
882 	}
883 
884 	if (!vc4->is_vc5)
885 		hvs->dlist = hvs->regs + SCALER_DLIST_START;
886 	else
887 		hvs->dlist = hvs->regs + SCALER5_DLIST_START;
888 
889 	/* Upload filter kernels.  We only have the one for now, so we
890 	 * keep it around for the lifetime of the driver.
891 	 */
892 	ret = vc4_hvs_upload_linear_kernel(hvs,
893 					   &hvs->mitchell_netravali_filter,
894 					   mitchell_netravali_1_3_1_3_kernel);
895 	if (ret)
896 		return ret;
897 
898 	reg = HVS_READ(SCALER_DISPECTRL);
899 	reg &= ~SCALER_DISPECTRL_DSP2_MUX_MASK;
900 	HVS_WRITE(SCALER_DISPECTRL,
901 		  reg | VC4_SET_FIELD(0, SCALER_DISPECTRL_DSP2_MUX));
902 
903 	reg = HVS_READ(SCALER_DISPCTRL);
904 	reg &= ~SCALER_DISPCTRL_DSP3_MUX_MASK;
905 	HVS_WRITE(SCALER_DISPCTRL,
906 		  reg | VC4_SET_FIELD(3, SCALER_DISPCTRL_DSP3_MUX));
907 
908 	reg = HVS_READ(SCALER_DISPEOLN);
909 	reg &= ~SCALER_DISPEOLN_DSP4_MUX_MASK;
910 	HVS_WRITE(SCALER_DISPEOLN,
911 		  reg | VC4_SET_FIELD(3, SCALER_DISPEOLN_DSP4_MUX));
912 
913 	reg = HVS_READ(SCALER_DISPDITHER);
914 	reg &= ~SCALER_DISPDITHER_DSP5_MUX_MASK;
915 	HVS_WRITE(SCALER_DISPDITHER,
916 		  reg | VC4_SET_FIELD(3, SCALER_DISPDITHER_DSP5_MUX));
917 
918 	dispctrl = HVS_READ(SCALER_DISPCTRL);
919 
920 	dispctrl |= SCALER_DISPCTRL_ENABLE;
921 	dispctrl |= SCALER_DISPCTRL_DISPEIRQ(0) |
922 		    SCALER_DISPCTRL_DISPEIRQ(1) |
923 		    SCALER_DISPCTRL_DISPEIRQ(2);
924 
925 	if (!vc4->is_vc5)
926 		dispctrl &= ~(SCALER_DISPCTRL_DMAEIRQ |
927 			      SCALER_DISPCTRL_SLVWREIRQ |
928 			      SCALER_DISPCTRL_SLVRDEIRQ |
929 			      SCALER_DISPCTRL_DSPEIEOF(0) |
930 			      SCALER_DISPCTRL_DSPEIEOF(1) |
931 			      SCALER_DISPCTRL_DSPEIEOF(2) |
932 			      SCALER_DISPCTRL_DSPEIEOLN(0) |
933 			      SCALER_DISPCTRL_DSPEIEOLN(1) |
934 			      SCALER_DISPCTRL_DSPEIEOLN(2) |
935 			      SCALER_DISPCTRL_DSPEISLUR(0) |
936 			      SCALER_DISPCTRL_DSPEISLUR(1) |
937 			      SCALER_DISPCTRL_DSPEISLUR(2) |
938 			      SCALER_DISPCTRL_SCLEIRQ);
939 	else
940 		dispctrl &= ~(SCALER_DISPCTRL_DMAEIRQ |
941 			      SCALER5_DISPCTRL_SLVEIRQ |
942 			      SCALER5_DISPCTRL_DSPEIEOF(0) |
943 			      SCALER5_DISPCTRL_DSPEIEOF(1) |
944 			      SCALER5_DISPCTRL_DSPEIEOF(2) |
945 			      SCALER5_DISPCTRL_DSPEIEOLN(0) |
946 			      SCALER5_DISPCTRL_DSPEIEOLN(1) |
947 			      SCALER5_DISPCTRL_DSPEIEOLN(2) |
948 			      SCALER5_DISPCTRL_DSPEISLUR(0) |
949 			      SCALER5_DISPCTRL_DSPEISLUR(1) |
950 			      SCALER5_DISPCTRL_DSPEISLUR(2) |
951 			      SCALER_DISPCTRL_SCLEIRQ);
952 
953 
954 	/* Set AXI panic mode.
955 	 * VC4 panics when < 2 lines in FIFO.
956 	 * VC5 panics when less than 1 line in the FIFO.
957 	 */
958 	dispctrl &= ~(SCALER_DISPCTRL_PANIC0_MASK |
959 		      SCALER_DISPCTRL_PANIC1_MASK |
960 		      SCALER_DISPCTRL_PANIC2_MASK);
961 	dispctrl |= VC4_SET_FIELD(2, SCALER_DISPCTRL_PANIC0);
962 	dispctrl |= VC4_SET_FIELD(2, SCALER_DISPCTRL_PANIC1);
963 	dispctrl |= VC4_SET_FIELD(2, SCALER_DISPCTRL_PANIC2);
964 
965 	HVS_WRITE(SCALER_DISPCTRL, dispctrl);
966 
967 	/* Recompute Composite Output Buffer (COB) allocations for the displays
968 	 */
969 	if (!vc4->is_vc5) {
970 		/* The COB is 20736 pixels, or just over 10 lines at 2048 wide.
971 		 * The bottom 2048 pixels are full 32bpp RGBA (intended for the
972 		 * TXP composing RGBA to memory), whilst the remainder are only
973 		 * 24bpp RGB.
974 		 *
975 		 * Assign 3 lines to channels 1 & 2, and just over 4 lines to
976 		 * channel 0.
977 		 */
978 		#define VC4_COB_SIZE		20736
979 		#define VC4_COB_LINE_WIDTH	2048
980 		#define VC4_COB_NUM_LINES	3
981 		reg = 0;
982 		top = VC4_COB_LINE_WIDTH * VC4_COB_NUM_LINES;
983 		reg |= (top - 1) << 16;
984 		HVS_WRITE(SCALER_DISPBASE2, reg);
985 		reg = top;
986 		top += VC4_COB_LINE_WIDTH * VC4_COB_NUM_LINES;
987 		reg |= (top - 1) << 16;
988 		HVS_WRITE(SCALER_DISPBASE1, reg);
989 		reg = top;
990 		top = VC4_COB_SIZE;
991 		reg |= (top - 1) << 16;
992 		HVS_WRITE(SCALER_DISPBASE0, reg);
993 	} else {
994 		/* The COB is 44416 pixels, or 10.8 lines at 4096 wide.
995 		 * The bottom 4096 pixels are full RGBA (intended for the TXP
996 		 * composing RGBA to memory), whilst the remainder are only
997 		 * RGB. Addressing is always pixel wide.
998 		 *
999 		 * Assign 3 lines of 4096 to channels 1 & 2, and just over 4
1000 		 * lines. to channel 0.
1001 		 */
1002 		#define VC5_COB_SIZE		44416
1003 		#define VC5_COB_LINE_WIDTH	4096
1004 		#define VC5_COB_NUM_LINES	3
1005 		reg = 0;
1006 		top = VC5_COB_LINE_WIDTH * VC5_COB_NUM_LINES;
1007 		reg |= top << 16;
1008 		HVS_WRITE(SCALER_DISPBASE2, reg);
1009 		top += 16;
1010 		reg = top;
1011 		top += VC5_COB_LINE_WIDTH * VC5_COB_NUM_LINES;
1012 		reg |= top << 16;
1013 		HVS_WRITE(SCALER_DISPBASE1, reg);
1014 		top += 16;
1015 		reg = top;
1016 		top = VC5_COB_SIZE;
1017 		reg |= top << 16;
1018 		HVS_WRITE(SCALER_DISPBASE0, reg);
1019 	}
1020 
1021 	ret = devm_request_irq(dev, platform_get_irq(pdev, 0),
1022 			       vc4_hvs_irq_handler, 0, "vc4 hvs", drm);
1023 	if (ret)
1024 		return ret;
1025 
1026 	return 0;
1027 }
1028 
1029 static void vc4_hvs_unbind(struct device *dev, struct device *master,
1030 			   void *data)
1031 {
1032 	struct drm_device *drm = dev_get_drvdata(master);
1033 	struct vc4_dev *vc4 = to_vc4_dev(drm);
1034 	struct vc4_hvs *hvs = vc4->hvs;
1035 	struct drm_mm_node *node, *next;
1036 
1037 	if (drm_mm_node_allocated(&vc4->hvs->mitchell_netravali_filter))
1038 		drm_mm_remove_node(&vc4->hvs->mitchell_netravali_filter);
1039 
1040 	drm_mm_for_each_node_safe(node, next, &vc4->hvs->dlist_mm)
1041 		drm_mm_remove_node(node);
1042 
1043 	drm_mm_takedown(&vc4->hvs->dlist_mm);
1044 
1045 	drm_mm_for_each_node_safe(node, next, &vc4->hvs->lbm_mm)
1046 		drm_mm_remove_node(node);
1047 	drm_mm_takedown(&vc4->hvs->lbm_mm);
1048 
1049 	clk_disable_unprepare(hvs->core_clk);
1050 
1051 	vc4->hvs = NULL;
1052 }
1053 
1054 static const struct component_ops vc4_hvs_ops = {
1055 	.bind   = vc4_hvs_bind,
1056 	.unbind = vc4_hvs_unbind,
1057 };
1058 
1059 static int vc4_hvs_dev_probe(struct platform_device *pdev)
1060 {
1061 	return component_add(&pdev->dev, &vc4_hvs_ops);
1062 }
1063 
1064 static int vc4_hvs_dev_remove(struct platform_device *pdev)
1065 {
1066 	component_del(&pdev->dev, &vc4_hvs_ops);
1067 	return 0;
1068 }
1069 
1070 static const struct of_device_id vc4_hvs_dt_match[] = {
1071 	{ .compatible = "brcm,bcm2711-hvs" },
1072 	{ .compatible = "brcm,bcm2835-hvs" },
1073 	{}
1074 };
1075 
1076 struct platform_driver vc4_hvs_driver = {
1077 	.probe = vc4_hvs_dev_probe,
1078 	.remove = vc4_hvs_dev_remove,
1079 	.driver = {
1080 		.name = "vc4_hvs",
1081 		.of_match_table = vc4_hvs_dt_match,
1082 	},
1083 };
1084