xref: /openbmc/linux/drivers/gpu/drm/vc4/vc4_hvs.c (revision f59a3ee6)
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 "vc4_drv.h"
32 #include "vc4_regs.h"
33 
34 static const struct debugfs_reg32 hvs_regs[] = {
35 	VC4_REG32(SCALER_DISPCTRL),
36 	VC4_REG32(SCALER_DISPSTAT),
37 	VC4_REG32(SCALER_DISPID),
38 	VC4_REG32(SCALER_DISPECTRL),
39 	VC4_REG32(SCALER_DISPPROF),
40 	VC4_REG32(SCALER_DISPDITHER),
41 	VC4_REG32(SCALER_DISPEOLN),
42 	VC4_REG32(SCALER_DISPLIST0),
43 	VC4_REG32(SCALER_DISPLIST1),
44 	VC4_REG32(SCALER_DISPLIST2),
45 	VC4_REG32(SCALER_DISPLSTAT),
46 	VC4_REG32(SCALER_DISPLACT0),
47 	VC4_REG32(SCALER_DISPLACT1),
48 	VC4_REG32(SCALER_DISPLACT2),
49 	VC4_REG32(SCALER_DISPCTRL0),
50 	VC4_REG32(SCALER_DISPBKGND0),
51 	VC4_REG32(SCALER_DISPSTAT0),
52 	VC4_REG32(SCALER_DISPBASE0),
53 	VC4_REG32(SCALER_DISPCTRL1),
54 	VC4_REG32(SCALER_DISPBKGND1),
55 	VC4_REG32(SCALER_DISPSTAT1),
56 	VC4_REG32(SCALER_DISPBASE1),
57 	VC4_REG32(SCALER_DISPCTRL2),
58 	VC4_REG32(SCALER_DISPBKGND2),
59 	VC4_REG32(SCALER_DISPSTAT2),
60 	VC4_REG32(SCALER_DISPBASE2),
61 	VC4_REG32(SCALER_DISPALPHA2),
62 	VC4_REG32(SCALER_OLEDOFFS),
63 	VC4_REG32(SCALER_OLEDCOEF0),
64 	VC4_REG32(SCALER_OLEDCOEF1),
65 	VC4_REG32(SCALER_OLEDCOEF2),
66 };
67 
68 void vc4_hvs_dump_state(struct vc4_hvs *hvs)
69 {
70 	struct drm_device *drm = &hvs->vc4->base;
71 	struct drm_printer p = drm_info_printer(&hvs->pdev->dev);
72 	int idx, i;
73 
74 	if (!drm_dev_enter(drm, &idx))
75 		return;
76 
77 	drm_print_regset32(&p, &hvs->regset);
78 
79 	DRM_INFO("HVS ctx:\n");
80 	for (i = 0; i < 64; i += 4) {
81 		DRM_INFO("0x%08x (%s): 0x%08x 0x%08x 0x%08x 0x%08x\n",
82 			 i * 4, i < HVS_BOOTLOADER_DLIST_END ? "B" : "D",
83 			 readl((u32 __iomem *)hvs->dlist + i + 0),
84 			 readl((u32 __iomem *)hvs->dlist + i + 1),
85 			 readl((u32 __iomem *)hvs->dlist + i + 2),
86 			 readl((u32 __iomem *)hvs->dlist + i + 3));
87 	}
88 
89 	drm_dev_exit(idx);
90 }
91 
92 static int vc4_hvs_debugfs_underrun(struct seq_file *m, void *data)
93 {
94 	struct drm_info_node *node = m->private;
95 	struct drm_device *dev = node->minor->dev;
96 	struct vc4_dev *vc4 = to_vc4_dev(dev);
97 	struct drm_printer p = drm_seq_file_printer(m);
98 
99 	drm_printf(&p, "%d\n", atomic_read(&vc4->underrun));
100 
101 	return 0;
102 }
103 
104 static int vc4_hvs_debugfs_dlist(struct seq_file *m, void *data)
105 {
106 	struct drm_info_node *node = m->private;
107 	struct drm_device *dev = node->minor->dev;
108 	struct vc4_dev *vc4 = to_vc4_dev(dev);
109 	struct vc4_hvs *hvs = vc4->hvs;
110 	struct drm_printer p = drm_seq_file_printer(m);
111 	unsigned int next_entry_start = 0;
112 	unsigned int i, j;
113 	u32 dlist_word, dispstat;
114 
115 	for (i = 0; i < SCALER_CHANNELS_COUNT; i++) {
116 		dispstat = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTATX(i)),
117 					 SCALER_DISPSTATX_MODE);
118 		if (dispstat == SCALER_DISPSTATX_MODE_DISABLED ||
119 		    dispstat == SCALER_DISPSTATX_MODE_EOF) {
120 			drm_printf(&p, "HVS chan %u disabled\n", i);
121 			continue;
122 		}
123 
124 		drm_printf(&p, "HVS chan %u:\n", i);
125 
126 		for (j = HVS_READ(SCALER_DISPLISTX(i)); j < 256; j++) {
127 			dlist_word = readl((u32 __iomem *)vc4->hvs->dlist + j);
128 			drm_printf(&p, "dlist: %02d: 0x%08x\n", j,
129 				   dlist_word);
130 			if (!next_entry_start ||
131 			    next_entry_start == j) {
132 				if (dlist_word & SCALER_CTL0_END)
133 					break;
134 				next_entry_start = j +
135 					VC4_GET_FIELD(dlist_word,
136 						      SCALER_CTL0_SIZE);
137 			}
138 		}
139 	}
140 
141 	return 0;
142 }
143 
144 /* The filter kernel is composed of dwords each containing 3 9-bit
145  * signed integers packed next to each other.
146  */
147 #define VC4_INT_TO_COEFF(coeff) (coeff & 0x1ff)
148 #define VC4_PPF_FILTER_WORD(c0, c1, c2)				\
149 	((((c0) & 0x1ff) << 0) |				\
150 	 (((c1) & 0x1ff) << 9) |				\
151 	 (((c2) & 0x1ff) << 18))
152 
153 /* The whole filter kernel is arranged as the coefficients 0-16 going
154  * up, then a pad, then 17-31 going down and reversed within the
155  * dwords.  This means that a linear phase kernel (where it's
156  * symmetrical at the boundary between 15 and 16) has the last 5
157  * dwords matching the first 5, but reversed.
158  */
159 #define VC4_LINEAR_PHASE_KERNEL(c0, c1, c2, c3, c4, c5, c6, c7, c8,	\
160 				c9, c10, c11, c12, c13, c14, c15)	\
161 	{VC4_PPF_FILTER_WORD(c0, c1, c2),				\
162 	 VC4_PPF_FILTER_WORD(c3, c4, c5),				\
163 	 VC4_PPF_FILTER_WORD(c6, c7, c8),				\
164 	 VC4_PPF_FILTER_WORD(c9, c10, c11),				\
165 	 VC4_PPF_FILTER_WORD(c12, c13, c14),				\
166 	 VC4_PPF_FILTER_WORD(c15, c15, 0)}
167 
168 #define VC4_LINEAR_PHASE_KERNEL_DWORDS 6
169 #define VC4_KERNEL_DWORDS (VC4_LINEAR_PHASE_KERNEL_DWORDS * 2 - 1)
170 
171 /* Recommended B=1/3, C=1/3 filter choice from Mitchell/Netravali.
172  * http://www.cs.utexas.edu/~fussell/courses/cs384g/lectures/mitchell/Mitchell.pdf
173  */
174 static const u32 mitchell_netravali_1_3_1_3_kernel[] =
175 	VC4_LINEAR_PHASE_KERNEL(0, -2, -6, -8, -10, -8, -3, 2, 18,
176 				50, 82, 119, 155, 187, 213, 227);
177 
178 static int vc4_hvs_upload_linear_kernel(struct vc4_hvs *hvs,
179 					struct drm_mm_node *space,
180 					const u32 *kernel)
181 {
182 	int ret, i;
183 	u32 __iomem *dst_kernel;
184 
185 	/*
186 	 * NOTE: We don't need a call to drm_dev_enter()/drm_dev_exit()
187 	 * here since that function is only called from vc4_hvs_bind().
188 	 */
189 
190 	ret = drm_mm_insert_node(&hvs->dlist_mm, space, VC4_KERNEL_DWORDS);
191 	if (ret) {
192 		DRM_ERROR("Failed to allocate space for filter kernel: %d\n",
193 			  ret);
194 		return ret;
195 	}
196 
197 	dst_kernel = hvs->dlist + space->start;
198 
199 	for (i = 0; i < VC4_KERNEL_DWORDS; i++) {
200 		if (i < VC4_LINEAR_PHASE_KERNEL_DWORDS)
201 			writel(kernel[i], &dst_kernel[i]);
202 		else {
203 			writel(kernel[VC4_KERNEL_DWORDS - i - 1],
204 			       &dst_kernel[i]);
205 		}
206 	}
207 
208 	return 0;
209 }
210 
211 static void vc4_hvs_lut_load(struct vc4_hvs *hvs,
212 			     struct vc4_crtc *vc4_crtc)
213 {
214 	struct drm_device *drm = &hvs->vc4->base;
215 	struct drm_crtc *crtc = &vc4_crtc->base;
216 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
217 	int idx;
218 	u32 i;
219 
220 	if (!drm_dev_enter(drm, &idx))
221 		return;
222 
223 	/* The LUT memory is laid out with each HVS channel in order,
224 	 * each of which takes 256 writes for R, 256 for G, then 256
225 	 * for B.
226 	 */
227 	HVS_WRITE(SCALER_GAMADDR,
228 		  SCALER_GAMADDR_AUTOINC |
229 		  (vc4_state->assigned_channel * 3 * crtc->gamma_size));
230 
231 	for (i = 0; i < crtc->gamma_size; i++)
232 		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_r[i]);
233 	for (i = 0; i < crtc->gamma_size; i++)
234 		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_g[i]);
235 	for (i = 0; i < crtc->gamma_size; i++)
236 		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_b[i]);
237 
238 	drm_dev_exit(idx);
239 }
240 
241 static void vc4_hvs_update_gamma_lut(struct vc4_hvs *hvs,
242 				     struct vc4_crtc *vc4_crtc)
243 {
244 	struct drm_crtc_state *crtc_state = vc4_crtc->base.state;
245 	struct drm_color_lut *lut = crtc_state->gamma_lut->data;
246 	u32 length = drm_color_lut_size(crtc_state->gamma_lut);
247 	u32 i;
248 
249 	for (i = 0; i < length; i++) {
250 		vc4_crtc->lut_r[i] = drm_color_lut_extract(lut[i].red, 8);
251 		vc4_crtc->lut_g[i] = drm_color_lut_extract(lut[i].green, 8);
252 		vc4_crtc->lut_b[i] = drm_color_lut_extract(lut[i].blue, 8);
253 	}
254 
255 	vc4_hvs_lut_load(hvs, vc4_crtc);
256 }
257 
258 u8 vc4_hvs_get_fifo_frame_count(struct vc4_hvs *hvs, unsigned int fifo)
259 {
260 	struct drm_device *drm = &hvs->vc4->base;
261 	u8 field = 0;
262 	int idx;
263 
264 	if (!drm_dev_enter(drm, &idx))
265 		return 0;
266 
267 	switch (fifo) {
268 	case 0:
269 		field = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTAT1),
270 				      SCALER_DISPSTAT1_FRCNT0);
271 		break;
272 	case 1:
273 		field = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTAT1),
274 				      SCALER_DISPSTAT1_FRCNT1);
275 		break;
276 	case 2:
277 		field = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTAT2),
278 				      SCALER_DISPSTAT2_FRCNT2);
279 		break;
280 	}
281 
282 	drm_dev_exit(idx);
283 	return field;
284 }
285 
286 int vc4_hvs_get_fifo_from_output(struct vc4_hvs *hvs, unsigned int output)
287 {
288 	struct vc4_dev *vc4 = hvs->vc4;
289 	u32 reg;
290 	int ret;
291 
292 	if (!vc4->is_vc5)
293 		return output;
294 
295 	/*
296 	 * NOTE: We should probably use drm_dev_enter()/drm_dev_exit()
297 	 * here, but this function is only used during the DRM device
298 	 * initialization, so we should be fine.
299 	 */
300 
301 	switch (output) {
302 	case 0:
303 		return 0;
304 
305 	case 1:
306 		return 1;
307 
308 	case 2:
309 		reg = HVS_READ(SCALER_DISPECTRL);
310 		ret = FIELD_GET(SCALER_DISPECTRL_DSP2_MUX_MASK, reg);
311 		if (ret == 0)
312 			return 2;
313 
314 		return 0;
315 
316 	case 3:
317 		reg = HVS_READ(SCALER_DISPCTRL);
318 		ret = FIELD_GET(SCALER_DISPCTRL_DSP3_MUX_MASK, reg);
319 		if (ret == 3)
320 			return -EPIPE;
321 
322 		return ret;
323 
324 	case 4:
325 		reg = HVS_READ(SCALER_DISPEOLN);
326 		ret = FIELD_GET(SCALER_DISPEOLN_DSP4_MUX_MASK, reg);
327 		if (ret == 3)
328 			return -EPIPE;
329 
330 		return ret;
331 
332 	case 5:
333 		reg = HVS_READ(SCALER_DISPDITHER);
334 		ret = FIELD_GET(SCALER_DISPDITHER_DSP5_MUX_MASK, reg);
335 		if (ret == 3)
336 			return -EPIPE;
337 
338 		return ret;
339 
340 	default:
341 		return -EPIPE;
342 	}
343 }
344 
345 static int vc4_hvs_init_channel(struct vc4_hvs *hvs, struct drm_crtc *crtc,
346 				struct drm_display_mode *mode, bool oneshot)
347 {
348 	struct vc4_dev *vc4 = hvs->vc4;
349 	struct drm_device *drm = &vc4->base;
350 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
351 	struct vc4_crtc_state *vc4_crtc_state = to_vc4_crtc_state(crtc->state);
352 	unsigned int chan = vc4_crtc_state->assigned_channel;
353 	bool interlace = mode->flags & DRM_MODE_FLAG_INTERLACE;
354 	u32 dispbkgndx;
355 	u32 dispctrl;
356 	int idx;
357 
358 	if (!drm_dev_enter(drm, &idx))
359 		return -ENODEV;
360 
361 	HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
362 	HVS_WRITE(SCALER_DISPCTRLX(chan), SCALER_DISPCTRLX_RESET);
363 	HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
364 
365 	/* Turn on the scaler, which will wait for vstart to start
366 	 * compositing.
367 	 * When feeding the transposer, we should operate in oneshot
368 	 * mode.
369 	 */
370 	dispctrl = SCALER_DISPCTRLX_ENABLE;
371 
372 	if (!vc4->is_vc5)
373 		dispctrl |= VC4_SET_FIELD(mode->hdisplay,
374 					  SCALER_DISPCTRLX_WIDTH) |
375 			    VC4_SET_FIELD(mode->vdisplay,
376 					  SCALER_DISPCTRLX_HEIGHT) |
377 			    (oneshot ? SCALER_DISPCTRLX_ONESHOT : 0);
378 	else
379 		dispctrl |= VC4_SET_FIELD(mode->hdisplay,
380 					  SCALER5_DISPCTRLX_WIDTH) |
381 			    VC4_SET_FIELD(mode->vdisplay,
382 					  SCALER5_DISPCTRLX_HEIGHT) |
383 			    (oneshot ? SCALER5_DISPCTRLX_ONESHOT : 0);
384 
385 	HVS_WRITE(SCALER_DISPCTRLX(chan), dispctrl);
386 
387 	dispbkgndx = HVS_READ(SCALER_DISPBKGNDX(chan));
388 	dispbkgndx &= ~SCALER_DISPBKGND_GAMMA;
389 	dispbkgndx &= ~SCALER_DISPBKGND_INTERLACE;
390 
391 	HVS_WRITE(SCALER_DISPBKGNDX(chan), dispbkgndx |
392 		  SCALER_DISPBKGND_AUTOHS |
393 		  ((!vc4->is_vc5) ? SCALER_DISPBKGND_GAMMA : 0) |
394 		  (interlace ? SCALER_DISPBKGND_INTERLACE : 0));
395 
396 	/* Reload the LUT, since the SRAMs would have been disabled if
397 	 * all CRTCs had SCALER_DISPBKGND_GAMMA unset at once.
398 	 */
399 	vc4_hvs_lut_load(hvs, vc4_crtc);
400 
401 	drm_dev_exit(idx);
402 
403 	return 0;
404 }
405 
406 void vc4_hvs_stop_channel(struct vc4_hvs *hvs, unsigned int chan)
407 {
408 	struct drm_device *drm = &hvs->vc4->base;
409 	int idx;
410 
411 	if (!drm_dev_enter(drm, &idx))
412 		return;
413 
414 	if (HVS_READ(SCALER_DISPCTRLX(chan)) & SCALER_DISPCTRLX_ENABLE)
415 		goto out;
416 
417 	HVS_WRITE(SCALER_DISPCTRLX(chan),
418 		  HVS_READ(SCALER_DISPCTRLX(chan)) | SCALER_DISPCTRLX_RESET);
419 	HVS_WRITE(SCALER_DISPCTRLX(chan),
420 		  HVS_READ(SCALER_DISPCTRLX(chan)) & ~SCALER_DISPCTRLX_ENABLE);
421 
422 	/* Once we leave, the scaler should be disabled and its fifo empty. */
423 	WARN_ON_ONCE(HVS_READ(SCALER_DISPCTRLX(chan)) & SCALER_DISPCTRLX_RESET);
424 
425 	WARN_ON_ONCE(VC4_GET_FIELD(HVS_READ(SCALER_DISPSTATX(chan)),
426 				   SCALER_DISPSTATX_MODE) !=
427 		     SCALER_DISPSTATX_MODE_DISABLED);
428 
429 	WARN_ON_ONCE((HVS_READ(SCALER_DISPSTATX(chan)) &
430 		      (SCALER_DISPSTATX_FULL | SCALER_DISPSTATX_EMPTY)) !=
431 		     SCALER_DISPSTATX_EMPTY);
432 
433 out:
434 	drm_dev_exit(idx);
435 }
436 
437 int vc4_hvs_atomic_check(struct drm_crtc *crtc, struct drm_atomic_state *state)
438 {
439 	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
440 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc_state);
441 	struct drm_device *dev = crtc->dev;
442 	struct vc4_dev *vc4 = to_vc4_dev(dev);
443 	struct drm_plane *plane;
444 	unsigned long flags;
445 	const struct drm_plane_state *plane_state;
446 	u32 dlist_count = 0;
447 	int ret;
448 
449 	/* The pixelvalve can only feed one encoder (and encoders are
450 	 * 1:1 with connectors.)
451 	 */
452 	if (hweight32(crtc_state->connector_mask) > 1)
453 		return -EINVAL;
454 
455 	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, crtc_state)
456 		dlist_count += vc4_plane_dlist_size(plane_state);
457 
458 	dlist_count++; /* Account for SCALER_CTL0_END. */
459 
460 	spin_lock_irqsave(&vc4->hvs->mm_lock, flags);
461 	ret = drm_mm_insert_node(&vc4->hvs->dlist_mm, &vc4_state->mm,
462 				 dlist_count);
463 	spin_unlock_irqrestore(&vc4->hvs->mm_lock, flags);
464 	if (ret)
465 		return ret;
466 
467 	return 0;
468 }
469 
470 static void vc4_hvs_install_dlist(struct drm_crtc *crtc)
471 {
472 	struct drm_device *dev = crtc->dev;
473 	struct vc4_dev *vc4 = to_vc4_dev(dev);
474 	struct vc4_hvs *hvs = vc4->hvs;
475 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
476 	int idx;
477 
478 	if (!drm_dev_enter(dev, &idx))
479 		return;
480 
481 	HVS_WRITE(SCALER_DISPLISTX(vc4_state->assigned_channel),
482 		  vc4_state->mm.start);
483 
484 	drm_dev_exit(idx);
485 }
486 
487 static void vc4_hvs_update_dlist(struct drm_crtc *crtc)
488 {
489 	struct drm_device *dev = crtc->dev;
490 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
491 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
492 	unsigned long flags;
493 
494 	if (crtc->state->event) {
495 		crtc->state->event->pipe = drm_crtc_index(crtc);
496 
497 		WARN_ON(drm_crtc_vblank_get(crtc) != 0);
498 
499 		spin_lock_irqsave(&dev->event_lock, flags);
500 
501 		if (!vc4_crtc->feeds_txp || vc4_state->txp_armed) {
502 			vc4_crtc->event = crtc->state->event;
503 			crtc->state->event = NULL;
504 		}
505 
506 		spin_unlock_irqrestore(&dev->event_lock, flags);
507 	}
508 
509 	spin_lock_irqsave(&vc4_crtc->irq_lock, flags);
510 	vc4_crtc->current_dlist = vc4_state->mm.start;
511 	spin_unlock_irqrestore(&vc4_crtc->irq_lock, flags);
512 }
513 
514 void vc4_hvs_atomic_begin(struct drm_crtc *crtc,
515 			  struct drm_atomic_state *state)
516 {
517 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
518 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
519 	unsigned long flags;
520 
521 	spin_lock_irqsave(&vc4_crtc->irq_lock, flags);
522 	vc4_crtc->current_hvs_channel = vc4_state->assigned_channel;
523 	spin_unlock_irqrestore(&vc4_crtc->irq_lock, flags);
524 }
525 
526 void vc4_hvs_atomic_enable(struct drm_crtc *crtc,
527 			   struct drm_atomic_state *state)
528 {
529 	struct drm_device *dev = crtc->dev;
530 	struct vc4_dev *vc4 = to_vc4_dev(dev);
531 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
532 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
533 	bool oneshot = vc4_crtc->feeds_txp;
534 
535 	vc4_hvs_install_dlist(crtc);
536 	vc4_hvs_update_dlist(crtc);
537 	vc4_hvs_init_channel(vc4->hvs, crtc, mode, oneshot);
538 }
539 
540 void vc4_hvs_atomic_disable(struct drm_crtc *crtc,
541 			    struct drm_atomic_state *state)
542 {
543 	struct drm_device *dev = crtc->dev;
544 	struct vc4_dev *vc4 = to_vc4_dev(dev);
545 	struct drm_crtc_state *old_state = drm_atomic_get_old_crtc_state(state, crtc);
546 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(old_state);
547 	unsigned int chan = vc4_state->assigned_channel;
548 
549 	vc4_hvs_stop_channel(vc4->hvs, chan);
550 }
551 
552 void vc4_hvs_atomic_flush(struct drm_crtc *crtc,
553 			  struct drm_atomic_state *state)
554 {
555 	struct drm_crtc_state *old_state = drm_atomic_get_old_crtc_state(state,
556 									 crtc);
557 	struct drm_device *dev = crtc->dev;
558 	struct vc4_dev *vc4 = to_vc4_dev(dev);
559 	struct vc4_hvs *hvs = vc4->hvs;
560 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
561 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
562 	unsigned int channel = vc4_state->assigned_channel;
563 	struct drm_plane *plane;
564 	struct vc4_plane_state *vc4_plane_state;
565 	bool debug_dump_regs = false;
566 	bool enable_bg_fill = false;
567 	u32 __iomem *dlist_start = vc4->hvs->dlist + vc4_state->mm.start;
568 	u32 __iomem *dlist_next = dlist_start;
569 	int idx;
570 
571 	if (!drm_dev_enter(dev, &idx)) {
572 		vc4_crtc_send_vblank(crtc);
573 		return;
574 	}
575 
576 	if (debug_dump_regs) {
577 		DRM_INFO("CRTC %d HVS before:\n", drm_crtc_index(crtc));
578 		vc4_hvs_dump_state(hvs);
579 	}
580 
581 	/* Copy all the active planes' dlist contents to the hardware dlist. */
582 	drm_atomic_crtc_for_each_plane(plane, crtc) {
583 		/* Is this the first active plane? */
584 		if (dlist_next == dlist_start) {
585 			/* We need to enable background fill when a plane
586 			 * could be alpha blending from the background, i.e.
587 			 * where no other plane is underneath. It suffices to
588 			 * consider the first active plane here since we set
589 			 * needs_bg_fill such that either the first plane
590 			 * already needs it or all planes on top blend from
591 			 * the first or a lower plane.
592 			 */
593 			vc4_plane_state = to_vc4_plane_state(plane->state);
594 			enable_bg_fill = vc4_plane_state->needs_bg_fill;
595 		}
596 
597 		dlist_next += vc4_plane_write_dlist(plane, dlist_next);
598 	}
599 
600 	writel(SCALER_CTL0_END, dlist_next);
601 	dlist_next++;
602 
603 	WARN_ON_ONCE(dlist_next - dlist_start != vc4_state->mm.size);
604 
605 	if (enable_bg_fill)
606 		/* This sets a black background color fill, as is the case
607 		 * with other DRM drivers.
608 		 */
609 		HVS_WRITE(SCALER_DISPBKGNDX(channel),
610 			  HVS_READ(SCALER_DISPBKGNDX(channel)) |
611 			  SCALER_DISPBKGND_FILL);
612 
613 	/* Only update DISPLIST if the CRTC was already running and is not
614 	 * being disabled.
615 	 * vc4_crtc_enable() takes care of updating the dlist just after
616 	 * re-enabling VBLANK interrupts and before enabling the engine.
617 	 * If the CRTC is being disabled, there's no point in updating this
618 	 * information.
619 	 */
620 	if (crtc->state->active && old_state->active) {
621 		vc4_hvs_install_dlist(crtc);
622 		vc4_hvs_update_dlist(crtc);
623 	}
624 
625 	if (crtc->state->color_mgmt_changed) {
626 		u32 dispbkgndx = HVS_READ(SCALER_DISPBKGNDX(channel));
627 
628 		if (crtc->state->gamma_lut) {
629 			vc4_hvs_update_gamma_lut(hvs, vc4_crtc);
630 			dispbkgndx |= SCALER_DISPBKGND_GAMMA;
631 		} else {
632 			/* Unsetting DISPBKGND_GAMMA skips the gamma lut step
633 			 * in hardware, which is the same as a linear lut that
634 			 * DRM expects us to use in absence of a user lut.
635 			 */
636 			dispbkgndx &= ~SCALER_DISPBKGND_GAMMA;
637 		}
638 		HVS_WRITE(SCALER_DISPBKGNDX(channel), dispbkgndx);
639 	}
640 
641 	if (debug_dump_regs) {
642 		DRM_INFO("CRTC %d HVS after:\n", drm_crtc_index(crtc));
643 		vc4_hvs_dump_state(hvs);
644 	}
645 
646 	drm_dev_exit(idx);
647 }
648 
649 void vc4_hvs_mask_underrun(struct vc4_hvs *hvs, int channel)
650 {
651 	struct drm_device *drm = &hvs->vc4->base;
652 	u32 dispctrl;
653 	int idx;
654 
655 	if (!drm_dev_enter(drm, &idx))
656 		return;
657 
658 	dispctrl = HVS_READ(SCALER_DISPCTRL);
659 	dispctrl &= ~SCALER_DISPCTRL_DSPEISLUR(channel);
660 
661 	HVS_WRITE(SCALER_DISPCTRL, dispctrl);
662 
663 	drm_dev_exit(idx);
664 }
665 
666 void vc4_hvs_unmask_underrun(struct vc4_hvs *hvs, int channel)
667 {
668 	struct drm_device *drm = &hvs->vc4->base;
669 	u32 dispctrl;
670 	int idx;
671 
672 	if (!drm_dev_enter(drm, &idx))
673 		return;
674 
675 	dispctrl = HVS_READ(SCALER_DISPCTRL);
676 	dispctrl |= SCALER_DISPCTRL_DSPEISLUR(channel);
677 
678 	HVS_WRITE(SCALER_DISPSTAT,
679 		  SCALER_DISPSTAT_EUFLOW(channel));
680 	HVS_WRITE(SCALER_DISPCTRL, dispctrl);
681 
682 	drm_dev_exit(idx);
683 }
684 
685 static void vc4_hvs_report_underrun(struct drm_device *dev)
686 {
687 	struct vc4_dev *vc4 = to_vc4_dev(dev);
688 
689 	atomic_inc(&vc4->underrun);
690 	DRM_DEV_ERROR(dev->dev, "HVS underrun\n");
691 }
692 
693 static irqreturn_t vc4_hvs_irq_handler(int irq, void *data)
694 {
695 	struct drm_device *dev = data;
696 	struct vc4_dev *vc4 = to_vc4_dev(dev);
697 	struct vc4_hvs *hvs = vc4->hvs;
698 	irqreturn_t irqret = IRQ_NONE;
699 	int channel;
700 	u32 control;
701 	u32 status;
702 
703 	/*
704 	 * NOTE: We don't need to protect the register access using
705 	 * drm_dev_enter() there because the interrupt handler lifetime
706 	 * is tied to the device itself, and not to the DRM device.
707 	 *
708 	 * So when the device will be gone, one of the first thing we
709 	 * will be doing will be to unregister the interrupt handler,
710 	 * and then unregister the DRM device. drm_dev_enter() would
711 	 * thus always succeed if we are here.
712 	 */
713 
714 	status = HVS_READ(SCALER_DISPSTAT);
715 	control = HVS_READ(SCALER_DISPCTRL);
716 
717 	for (channel = 0; channel < SCALER_CHANNELS_COUNT; channel++) {
718 		/* Interrupt masking is not always honored, so check it here. */
719 		if (status & SCALER_DISPSTAT_EUFLOW(channel) &&
720 		    control & SCALER_DISPCTRL_DSPEISLUR(channel)) {
721 			vc4_hvs_mask_underrun(hvs, channel);
722 			vc4_hvs_report_underrun(dev);
723 
724 			irqret = IRQ_HANDLED;
725 		}
726 	}
727 
728 	/* Clear every per-channel interrupt flag. */
729 	HVS_WRITE(SCALER_DISPSTAT, SCALER_DISPSTAT_IRQMASK(0) |
730 				   SCALER_DISPSTAT_IRQMASK(1) |
731 				   SCALER_DISPSTAT_IRQMASK(2));
732 
733 	return irqret;
734 }
735 
736 int vc4_hvs_debugfs_init(struct drm_minor *minor)
737 {
738 	struct drm_device *drm = minor->dev;
739 	struct vc4_dev *vc4 = to_vc4_dev(drm);
740 	struct vc4_hvs *hvs = vc4->hvs;
741 	int ret;
742 
743 	if (!vc4->hvs)
744 		return -ENODEV;
745 
746 	if (!vc4->is_vc5)
747 		debugfs_create_bool("hvs_load_tracker", S_IRUGO | S_IWUSR,
748 				    minor->debugfs_root,
749 				    &vc4->load_tracker_enabled);
750 
751 	ret = vc4_debugfs_add_file(minor, "hvs_dlists",
752 				   vc4_hvs_debugfs_dlist, NULL);
753 	if (ret)
754 		return ret;
755 
756 	ret = vc4_debugfs_add_file(minor, "hvs_underrun",
757 				   vc4_hvs_debugfs_underrun, NULL);
758 	if (ret)
759 		return ret;
760 
761 	ret = vc4_debugfs_add_regset32(minor, "hvs_regs",
762 				       &hvs->regset);
763 	if (ret)
764 		return ret;
765 
766 	return 0;
767 }
768 
769 static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
770 {
771 	struct platform_device *pdev = to_platform_device(dev);
772 	struct drm_device *drm = dev_get_drvdata(master);
773 	struct vc4_dev *vc4 = to_vc4_dev(drm);
774 	struct vc4_hvs *hvs = NULL;
775 	int ret;
776 	u32 dispctrl;
777 	u32 reg;
778 
779 	hvs = drmm_kzalloc(drm, sizeof(*hvs), GFP_KERNEL);
780 	if (!hvs)
781 		return -ENOMEM;
782 	hvs->vc4 = vc4;
783 	hvs->pdev = pdev;
784 
785 	hvs->regs = vc4_ioremap_regs(pdev, 0);
786 	if (IS_ERR(hvs->regs))
787 		return PTR_ERR(hvs->regs);
788 
789 	hvs->regset.base = hvs->regs;
790 	hvs->regset.regs = hvs_regs;
791 	hvs->regset.nregs = ARRAY_SIZE(hvs_regs);
792 
793 	if (vc4->is_vc5) {
794 		hvs->core_clk = devm_clk_get(&pdev->dev, NULL);
795 		if (IS_ERR(hvs->core_clk)) {
796 			dev_err(&pdev->dev, "Couldn't get core clock\n");
797 			return PTR_ERR(hvs->core_clk);
798 		}
799 
800 		ret = clk_prepare_enable(hvs->core_clk);
801 		if (ret) {
802 			dev_err(&pdev->dev, "Couldn't enable the core clock\n");
803 			return ret;
804 		}
805 	}
806 
807 	if (!vc4->is_vc5)
808 		hvs->dlist = hvs->regs + SCALER_DLIST_START;
809 	else
810 		hvs->dlist = hvs->regs + SCALER5_DLIST_START;
811 
812 	spin_lock_init(&hvs->mm_lock);
813 
814 	/* Set up the HVS display list memory manager.  We never
815 	 * overwrite the setup from the bootloader (just 128b out of
816 	 * our 16K), since we don't want to scramble the screen when
817 	 * transitioning from the firmware's boot setup to runtime.
818 	 */
819 	drm_mm_init(&hvs->dlist_mm,
820 		    HVS_BOOTLOADER_DLIST_END,
821 		    (SCALER_DLIST_SIZE >> 2) - HVS_BOOTLOADER_DLIST_END);
822 
823 	/* Set up the HVS LBM memory manager.  We could have some more
824 	 * complicated data structure that allowed reuse of LBM areas
825 	 * between planes when they don't overlap on the screen, but
826 	 * for now we just allocate globally.
827 	 */
828 	if (!vc4->is_vc5)
829 		/* 48k words of 2x12-bit pixels */
830 		drm_mm_init(&hvs->lbm_mm, 0, 48 * 1024);
831 	else
832 		/* 60k words of 4x12-bit pixels */
833 		drm_mm_init(&hvs->lbm_mm, 0, 60 * 1024);
834 
835 	/* Upload filter kernels.  We only have the one for now, so we
836 	 * keep it around for the lifetime of the driver.
837 	 */
838 	ret = vc4_hvs_upload_linear_kernel(hvs,
839 					   &hvs->mitchell_netravali_filter,
840 					   mitchell_netravali_1_3_1_3_kernel);
841 	if (ret)
842 		return ret;
843 
844 	vc4->hvs = hvs;
845 
846 	reg = HVS_READ(SCALER_DISPECTRL);
847 	reg &= ~SCALER_DISPECTRL_DSP2_MUX_MASK;
848 	HVS_WRITE(SCALER_DISPECTRL,
849 		  reg | VC4_SET_FIELD(0, SCALER_DISPECTRL_DSP2_MUX));
850 
851 	reg = HVS_READ(SCALER_DISPCTRL);
852 	reg &= ~SCALER_DISPCTRL_DSP3_MUX_MASK;
853 	HVS_WRITE(SCALER_DISPCTRL,
854 		  reg | VC4_SET_FIELD(3, SCALER_DISPCTRL_DSP3_MUX));
855 
856 	reg = HVS_READ(SCALER_DISPEOLN);
857 	reg &= ~SCALER_DISPEOLN_DSP4_MUX_MASK;
858 	HVS_WRITE(SCALER_DISPEOLN,
859 		  reg | VC4_SET_FIELD(3, SCALER_DISPEOLN_DSP4_MUX));
860 
861 	reg = HVS_READ(SCALER_DISPDITHER);
862 	reg &= ~SCALER_DISPDITHER_DSP5_MUX_MASK;
863 	HVS_WRITE(SCALER_DISPDITHER,
864 		  reg | VC4_SET_FIELD(3, SCALER_DISPDITHER_DSP5_MUX));
865 
866 	dispctrl = HVS_READ(SCALER_DISPCTRL);
867 
868 	dispctrl |= SCALER_DISPCTRL_ENABLE;
869 	dispctrl |= SCALER_DISPCTRL_DISPEIRQ(0) |
870 		    SCALER_DISPCTRL_DISPEIRQ(1) |
871 		    SCALER_DISPCTRL_DISPEIRQ(2);
872 
873 	dispctrl &= ~(SCALER_DISPCTRL_DMAEIRQ |
874 		      SCALER_DISPCTRL_SLVWREIRQ |
875 		      SCALER_DISPCTRL_SLVRDEIRQ |
876 		      SCALER_DISPCTRL_DSPEIEOF(0) |
877 		      SCALER_DISPCTRL_DSPEIEOF(1) |
878 		      SCALER_DISPCTRL_DSPEIEOF(2) |
879 		      SCALER_DISPCTRL_DSPEIEOLN(0) |
880 		      SCALER_DISPCTRL_DSPEIEOLN(1) |
881 		      SCALER_DISPCTRL_DSPEIEOLN(2) |
882 		      SCALER_DISPCTRL_DSPEISLUR(0) |
883 		      SCALER_DISPCTRL_DSPEISLUR(1) |
884 		      SCALER_DISPCTRL_DSPEISLUR(2) |
885 		      SCALER_DISPCTRL_SCLEIRQ);
886 
887 	HVS_WRITE(SCALER_DISPCTRL, dispctrl);
888 
889 	ret = devm_request_irq(dev, platform_get_irq(pdev, 0),
890 			       vc4_hvs_irq_handler, 0, "vc4 hvs", drm);
891 	if (ret)
892 		return ret;
893 
894 	return 0;
895 }
896 
897 static void vc4_hvs_unbind(struct device *dev, struct device *master,
898 			   void *data)
899 {
900 	struct drm_device *drm = dev_get_drvdata(master);
901 	struct vc4_dev *vc4 = to_vc4_dev(drm);
902 	struct vc4_hvs *hvs = vc4->hvs;
903 	struct drm_mm_node *node, *next;
904 
905 	if (drm_mm_node_allocated(&vc4->hvs->mitchell_netravali_filter))
906 		drm_mm_remove_node(&vc4->hvs->mitchell_netravali_filter);
907 
908 	drm_mm_for_each_node_safe(node, next, &vc4->hvs->dlist_mm)
909 		drm_mm_remove_node(node);
910 
911 	drm_mm_takedown(&vc4->hvs->dlist_mm);
912 
913 	drm_mm_for_each_node_safe(node, next, &vc4->hvs->lbm_mm)
914 		drm_mm_remove_node(node);
915 	drm_mm_takedown(&vc4->hvs->lbm_mm);
916 
917 	clk_disable_unprepare(hvs->core_clk);
918 
919 	vc4->hvs = NULL;
920 }
921 
922 static const struct component_ops vc4_hvs_ops = {
923 	.bind   = vc4_hvs_bind,
924 	.unbind = vc4_hvs_unbind,
925 };
926 
927 static int vc4_hvs_dev_probe(struct platform_device *pdev)
928 {
929 	return component_add(&pdev->dev, &vc4_hvs_ops);
930 }
931 
932 static int vc4_hvs_dev_remove(struct platform_device *pdev)
933 {
934 	component_del(&pdev->dev, &vc4_hvs_ops);
935 	return 0;
936 }
937 
938 static const struct of_device_id vc4_hvs_dt_match[] = {
939 	{ .compatible = "brcm,bcm2711-hvs" },
940 	{ .compatible = "brcm,bcm2835-hvs" },
941 	{}
942 };
943 
944 struct platform_driver vc4_hvs_driver = {
945 	.probe = vc4_hvs_dev_probe,
946 	.remove = vc4_hvs_dev_remove,
947 	.driver = {
948 		.name = "vc4_hvs",
949 		.of_match_table = vc4_hvs_dt_match,
950 	},
951 };
952