1 /*
2  * Copyright (C) 2012 Texas Instruments
3  * Author: Rob Clark <robdclark@gmail.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include "drm_flip_work.h"
19 #include <drm/drm_plane_helper.h>
20 
21 #include "tilcdc_drv.h"
22 #include "tilcdc_regs.h"
23 
24 #define TILCDC_VBLANK_SAFETY_THRESHOLD_US 1000
25 
26 struct tilcdc_crtc {
27 	struct drm_crtc base;
28 
29 	const struct tilcdc_panel_info *info;
30 	struct drm_pending_vblank_event *event;
31 	int dpms;
32 	wait_queue_head_t frame_done_wq;
33 	bool frame_done;
34 	spinlock_t irq_lock;
35 
36 	ktime_t last_vblank;
37 
38 	struct drm_framebuffer *curr_fb;
39 	struct drm_framebuffer *next_fb;
40 
41 	/* for deferred fb unref's: */
42 	struct drm_flip_work unref_work;
43 
44 	/* Only set if an external encoder is connected */
45 	bool simulate_vesa_sync;
46 
47 	int sync_lost_count;
48 	bool frame_intact;
49 };
50 #define to_tilcdc_crtc(x) container_of(x, struct tilcdc_crtc, base)
51 
52 static void unref_worker(struct drm_flip_work *work, void *val)
53 {
54 	struct tilcdc_crtc *tilcdc_crtc =
55 		container_of(work, struct tilcdc_crtc, unref_work);
56 	struct drm_device *dev = tilcdc_crtc->base.dev;
57 
58 	mutex_lock(&dev->mode_config.mutex);
59 	drm_framebuffer_unreference(val);
60 	mutex_unlock(&dev->mode_config.mutex);
61 }
62 
63 static void set_scanout(struct drm_crtc *crtc, struct drm_framebuffer *fb)
64 {
65 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
66 	struct drm_device *dev = crtc->dev;
67 	struct drm_gem_cma_object *gem;
68 	unsigned int depth, bpp;
69 	dma_addr_t start, end;
70 
71 	drm_fb_get_bpp_depth(fb->pixel_format, &depth, &bpp);
72 	gem = drm_fb_cma_get_gem_obj(fb, 0);
73 
74 	start = gem->paddr + fb->offsets[0] +
75 		crtc->y * fb->pitches[0] +
76 		crtc->x * bpp / 8;
77 
78 	end = start + (crtc->mode.vdisplay * fb->pitches[0]);
79 
80 	tilcdc_write(dev, LCDC_DMA_FB_BASE_ADDR_0_REG, start);
81 	tilcdc_write(dev, LCDC_DMA_FB_CEILING_ADDR_0_REG, end);
82 
83 	if (tilcdc_crtc->curr_fb)
84 		drm_flip_work_queue(&tilcdc_crtc->unref_work,
85 			tilcdc_crtc->curr_fb);
86 
87 	tilcdc_crtc->curr_fb = fb;
88 }
89 
90 static void reset(struct drm_crtc *crtc)
91 {
92 	struct drm_device *dev = crtc->dev;
93 	struct tilcdc_drm_private *priv = dev->dev_private;
94 
95 	if (priv->rev != 2)
96 		return;
97 
98 	tilcdc_set(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
99 	usleep_range(250, 1000);
100 	tilcdc_clear(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
101 }
102 
103 static void start(struct drm_crtc *crtc)
104 {
105 	struct drm_device *dev = crtc->dev;
106 
107 	reset(crtc);
108 
109 	tilcdc_clear(dev, LCDC_DMA_CTRL_REG, LCDC_DUAL_FRAME_BUFFER_ENABLE);
110 	tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_PALETTE_LOAD_MODE(DATA_ONLY));
111 	tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
112 }
113 
114 static void stop(struct drm_crtc *crtc)
115 {
116 	struct drm_device *dev = crtc->dev;
117 
118 	tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
119 }
120 
121 static void tilcdc_crtc_destroy(struct drm_crtc *crtc)
122 {
123 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
124 
125 	tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
126 
127 	of_node_put(crtc->port);
128 	drm_crtc_cleanup(crtc);
129 	drm_flip_work_cleanup(&tilcdc_crtc->unref_work);
130 }
131 
132 static int tilcdc_verify_fb(struct drm_crtc *crtc, struct drm_framebuffer *fb)
133 {
134 	struct drm_device *dev = crtc->dev;
135 	unsigned int depth, bpp;
136 
137 	drm_fb_get_bpp_depth(fb->pixel_format, &depth, &bpp);
138 
139 	if (fb->pitches[0] != crtc->mode.hdisplay * bpp / 8) {
140 		dev_err(dev->dev,
141 			"Invalid pitch: fb and crtc widths must be the same");
142 		return -EINVAL;
143 	}
144 
145 	return 0;
146 }
147 
148 static int tilcdc_crtc_page_flip(struct drm_crtc *crtc,
149 		struct drm_framebuffer *fb,
150 		struct drm_pending_vblank_event *event,
151 		uint32_t page_flip_flags)
152 {
153 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
154 	struct drm_device *dev = crtc->dev;
155 	int r;
156 	unsigned long flags;
157 	s64 tdiff;
158 	ktime_t next_vblank;
159 
160 	r = tilcdc_verify_fb(crtc, fb);
161 	if (r)
162 		return r;
163 
164 	if (tilcdc_crtc->event) {
165 		dev_err(dev->dev, "already pending page flip!\n");
166 		return -EBUSY;
167 	}
168 
169 	drm_framebuffer_reference(fb);
170 
171 	crtc->primary->fb = fb;
172 
173 	pm_runtime_get_sync(dev->dev);
174 
175 	spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
176 
177 	next_vblank = ktime_add_us(tilcdc_crtc->last_vblank,
178 		1000000 / crtc->hwmode.vrefresh);
179 
180 	tdiff = ktime_to_us(ktime_sub(next_vblank, ktime_get()));
181 
182 	if (tdiff >= TILCDC_VBLANK_SAFETY_THRESHOLD_US)
183 		set_scanout(crtc, fb);
184 	else
185 		tilcdc_crtc->next_fb = fb;
186 
187 	tilcdc_crtc->event = event;
188 
189 	spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
190 
191 	pm_runtime_put_sync(dev->dev);
192 
193 	return 0;
194 }
195 
196 void tilcdc_crtc_dpms(struct drm_crtc *crtc, int mode)
197 {
198 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
199 	struct drm_device *dev = crtc->dev;
200 	struct tilcdc_drm_private *priv = dev->dev_private;
201 
202 	/* we really only care about on or off: */
203 	if (mode != DRM_MODE_DPMS_ON)
204 		mode = DRM_MODE_DPMS_OFF;
205 
206 	if (tilcdc_crtc->dpms == mode)
207 		return;
208 
209 	tilcdc_crtc->dpms = mode;
210 
211 	if (mode == DRM_MODE_DPMS_ON) {
212 		pm_runtime_get_sync(dev->dev);
213 		start(crtc);
214 	} else {
215 		tilcdc_crtc->frame_done = false;
216 		stop(crtc);
217 
218 		/*
219 		 * if necessary wait for framedone irq which will still come
220 		 * before putting things to sleep..
221 		 */
222 		if (priv->rev == 2) {
223 			int ret = wait_event_timeout(
224 					tilcdc_crtc->frame_done_wq,
225 					tilcdc_crtc->frame_done,
226 					msecs_to_jiffies(50));
227 			if (ret == 0)
228 				dev_err(dev->dev, "timeout waiting for framedone\n");
229 		}
230 
231 		pm_runtime_put_sync(dev->dev);
232 
233 		if (tilcdc_crtc->next_fb) {
234 			drm_flip_work_queue(&tilcdc_crtc->unref_work,
235 					    tilcdc_crtc->next_fb);
236 			tilcdc_crtc->next_fb = NULL;
237 		}
238 
239 		if (tilcdc_crtc->curr_fb) {
240 			drm_flip_work_queue(&tilcdc_crtc->unref_work,
241 					    tilcdc_crtc->curr_fb);
242 			tilcdc_crtc->curr_fb = NULL;
243 		}
244 
245 		drm_flip_work_commit(&tilcdc_crtc->unref_work, priv->wq);
246 	}
247 }
248 
249 static bool tilcdc_crtc_mode_fixup(struct drm_crtc *crtc,
250 		const struct drm_display_mode *mode,
251 		struct drm_display_mode *adjusted_mode)
252 {
253 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
254 
255 	if (!tilcdc_crtc->simulate_vesa_sync)
256 		return true;
257 
258 	/*
259 	 * tilcdc does not generate VESA-compliant sync but aligns
260 	 * VS on the second edge of HS instead of first edge.
261 	 * We use adjusted_mode, to fixup sync by aligning both rising
262 	 * edges and add HSKEW offset to fix the sync.
263 	 */
264 	adjusted_mode->hskew = mode->hsync_end - mode->hsync_start;
265 	adjusted_mode->flags |= DRM_MODE_FLAG_HSKEW;
266 
267 	if (mode->flags & DRM_MODE_FLAG_NHSYNC) {
268 		adjusted_mode->flags |= DRM_MODE_FLAG_PHSYNC;
269 		adjusted_mode->flags &= ~DRM_MODE_FLAG_NHSYNC;
270 	} else {
271 		adjusted_mode->flags |= DRM_MODE_FLAG_NHSYNC;
272 		adjusted_mode->flags &= ~DRM_MODE_FLAG_PHSYNC;
273 	}
274 
275 	return true;
276 }
277 
278 static void tilcdc_crtc_prepare(struct drm_crtc *crtc)
279 {
280 	tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
281 }
282 
283 static void tilcdc_crtc_commit(struct drm_crtc *crtc)
284 {
285 	tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_ON);
286 }
287 
288 static int tilcdc_crtc_mode_set(struct drm_crtc *crtc,
289 		struct drm_display_mode *mode,
290 		struct drm_display_mode *adjusted_mode,
291 		int x, int y,
292 		struct drm_framebuffer *old_fb)
293 {
294 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
295 	struct drm_device *dev = crtc->dev;
296 	struct tilcdc_drm_private *priv = dev->dev_private;
297 	const struct tilcdc_panel_info *info = tilcdc_crtc->info;
298 	uint32_t reg, hbp, hfp, hsw, vbp, vfp, vsw;
299 	int ret;
300 
301 	ret = tilcdc_crtc_mode_valid(crtc, mode);
302 	if (WARN_ON(ret))
303 		return ret;
304 
305 	if (WARN_ON(!info))
306 		return -EINVAL;
307 
308 	ret = tilcdc_verify_fb(crtc, crtc->primary->fb);
309 	if (ret)
310 		return ret;
311 
312 	pm_runtime_get_sync(dev->dev);
313 
314 	/* Configure the Burst Size and fifo threshold of DMA: */
315 	reg = tilcdc_read(dev, LCDC_DMA_CTRL_REG) & ~0x00000770;
316 	switch (info->dma_burst_sz) {
317 	case 1:
318 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_1);
319 		break;
320 	case 2:
321 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_2);
322 		break;
323 	case 4:
324 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_4);
325 		break;
326 	case 8:
327 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_8);
328 		break;
329 	case 16:
330 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_16);
331 		break;
332 	default:
333 		return -EINVAL;
334 	}
335 	reg |= (info->fifo_th << 8);
336 	tilcdc_write(dev, LCDC_DMA_CTRL_REG, reg);
337 
338 	/* Configure timings: */
339 	hbp = mode->htotal - mode->hsync_end;
340 	hfp = mode->hsync_start - mode->hdisplay;
341 	hsw = mode->hsync_end - mode->hsync_start;
342 	vbp = mode->vtotal - mode->vsync_end;
343 	vfp = mode->vsync_start - mode->vdisplay;
344 	vsw = mode->vsync_end - mode->vsync_start;
345 
346 	DBG("%dx%d, hbp=%u, hfp=%u, hsw=%u, vbp=%u, vfp=%u, vsw=%u",
347 			mode->hdisplay, mode->vdisplay, hbp, hfp, hsw, vbp, vfp, vsw);
348 
349 	/* Configure the AC Bias Period and Number of Transitions per Interrupt: */
350 	reg = tilcdc_read(dev, LCDC_RASTER_TIMING_2_REG) & ~0x000fff00;
351 	reg |= LCDC_AC_BIAS_FREQUENCY(info->ac_bias) |
352 		LCDC_AC_BIAS_TRANSITIONS_PER_INT(info->ac_bias_intrpt);
353 
354 	/*
355 	 * subtract one from hfp, hbp, hsw because the hardware uses
356 	 * a value of 0 as 1
357 	 */
358 	if (priv->rev == 2) {
359 		/* clear bits we're going to set */
360 		reg &= ~0x78000033;
361 		reg |= ((hfp-1) & 0x300) >> 8;
362 		reg |= ((hbp-1) & 0x300) >> 4;
363 		reg |= ((hsw-1) & 0x3c0) << 21;
364 	}
365 	tilcdc_write(dev, LCDC_RASTER_TIMING_2_REG, reg);
366 
367 	reg = (((mode->hdisplay >> 4) - 1) << 4) |
368 		(((hbp-1) & 0xff) << 24) |
369 		(((hfp-1) & 0xff) << 16) |
370 		(((hsw-1) & 0x3f) << 10);
371 	if (priv->rev == 2)
372 		reg |= (((mode->hdisplay >> 4) - 1) & 0x40) >> 3;
373 	tilcdc_write(dev, LCDC_RASTER_TIMING_0_REG, reg);
374 
375 	reg = ((mode->vdisplay - 1) & 0x3ff) |
376 		((vbp & 0xff) << 24) |
377 		((vfp & 0xff) << 16) |
378 		(((vsw-1) & 0x3f) << 10);
379 	tilcdc_write(dev, LCDC_RASTER_TIMING_1_REG, reg);
380 
381 	/*
382 	 * be sure to set Bit 10 for the V2 LCDC controller,
383 	 * otherwise limited to 1024 pixels width, stopping
384 	 * 1920x1080 being suppoted.
385 	 */
386 	if (priv->rev == 2) {
387 		if ((mode->vdisplay - 1) & 0x400) {
388 			tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG,
389 				LCDC_LPP_B10);
390 		} else {
391 			tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG,
392 				LCDC_LPP_B10);
393 		}
394 	}
395 
396 	/* Configure display type: */
397 	reg = tilcdc_read(dev, LCDC_RASTER_CTRL_REG) &
398 		~(LCDC_TFT_MODE | LCDC_MONO_8BIT_MODE | LCDC_MONOCHROME_MODE |
399 			LCDC_V2_TFT_24BPP_MODE | LCDC_V2_TFT_24BPP_UNPACK | 0x000ff000);
400 	reg |= LCDC_TFT_MODE; /* no monochrome/passive support */
401 	if (info->tft_alt_mode)
402 		reg |= LCDC_TFT_ALT_ENABLE;
403 	if (priv->rev == 2) {
404 		unsigned int depth, bpp;
405 
406 		drm_fb_get_bpp_depth(crtc->primary->fb->pixel_format, &depth, &bpp);
407 		switch (bpp) {
408 		case 16:
409 			break;
410 		case 32:
411 			reg |= LCDC_V2_TFT_24BPP_UNPACK;
412 			/* fallthrough */
413 		case 24:
414 			reg |= LCDC_V2_TFT_24BPP_MODE;
415 			break;
416 		default:
417 			dev_err(dev->dev, "invalid pixel format\n");
418 			return -EINVAL;
419 		}
420 	}
421 	reg |= info->fdd < 12;
422 	tilcdc_write(dev, LCDC_RASTER_CTRL_REG, reg);
423 
424 	if (info->invert_pxl_clk)
425 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_PIXEL_CLOCK);
426 	else
427 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_PIXEL_CLOCK);
428 
429 	if (info->sync_ctrl)
430 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_CTRL);
431 	else
432 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_CTRL);
433 
434 	if (info->sync_edge)
435 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);
436 	else
437 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);
438 
439 	/*
440 	 * use value from adjusted_mode here as this might have been
441 	 * changed as part of the fixup for slave encoders to solve the
442 	 * issue where tilcdc timings are not VESA compliant
443 	 */
444 	if (adjusted_mode->flags & DRM_MODE_FLAG_NHSYNC)
445 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC);
446 	else
447 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC);
448 
449 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
450 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_VSYNC);
451 	else
452 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_VSYNC);
453 
454 	if (info->raster_order)
455 		tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ORDER);
456 	else
457 		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ORDER);
458 
459 	drm_framebuffer_reference(crtc->primary->fb);
460 
461 	set_scanout(crtc, crtc->primary->fb);
462 
463 	tilcdc_crtc_update_clk(crtc);
464 
465 	pm_runtime_put_sync(dev->dev);
466 
467 	return 0;
468 }
469 
470 static int tilcdc_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
471 		struct drm_framebuffer *old_fb)
472 {
473 	struct drm_device *dev = crtc->dev;
474 	int r;
475 
476 	r = tilcdc_verify_fb(crtc, crtc->primary->fb);
477 	if (r)
478 		return r;
479 
480 	drm_framebuffer_reference(crtc->primary->fb);
481 
482 	pm_runtime_get_sync(dev->dev);
483 
484 	set_scanout(crtc, crtc->primary->fb);
485 
486 	pm_runtime_put_sync(dev->dev);
487 
488 	return 0;
489 }
490 
491 static const struct drm_crtc_funcs tilcdc_crtc_funcs = {
492 		.destroy        = tilcdc_crtc_destroy,
493 		.set_config     = drm_crtc_helper_set_config,
494 		.page_flip      = tilcdc_crtc_page_flip,
495 };
496 
497 static const struct drm_crtc_helper_funcs tilcdc_crtc_helper_funcs = {
498 		.dpms           = tilcdc_crtc_dpms,
499 		.mode_fixup     = tilcdc_crtc_mode_fixup,
500 		.prepare        = tilcdc_crtc_prepare,
501 		.commit         = tilcdc_crtc_commit,
502 		.mode_set       = tilcdc_crtc_mode_set,
503 		.mode_set_base  = tilcdc_crtc_mode_set_base,
504 };
505 
506 int tilcdc_crtc_max_width(struct drm_crtc *crtc)
507 {
508 	struct drm_device *dev = crtc->dev;
509 	struct tilcdc_drm_private *priv = dev->dev_private;
510 	int max_width = 0;
511 
512 	if (priv->rev == 1)
513 		max_width = 1024;
514 	else if (priv->rev == 2)
515 		max_width = 2048;
516 
517 	return max_width;
518 }
519 
520 int tilcdc_crtc_mode_valid(struct drm_crtc *crtc, struct drm_display_mode *mode)
521 {
522 	struct tilcdc_drm_private *priv = crtc->dev->dev_private;
523 	unsigned int bandwidth;
524 	uint32_t hbp, hfp, hsw, vbp, vfp, vsw;
525 
526 	/*
527 	 * check to see if the width is within the range that
528 	 * the LCD Controller physically supports
529 	 */
530 	if (mode->hdisplay > tilcdc_crtc_max_width(crtc))
531 		return MODE_VIRTUAL_X;
532 
533 	/* width must be multiple of 16 */
534 	if (mode->hdisplay & 0xf)
535 		return MODE_VIRTUAL_X;
536 
537 	if (mode->vdisplay > 2048)
538 		return MODE_VIRTUAL_Y;
539 
540 	DBG("Processing mode %dx%d@%d with pixel clock %d",
541 		mode->hdisplay, mode->vdisplay,
542 		drm_mode_vrefresh(mode), mode->clock);
543 
544 	hbp = mode->htotal - mode->hsync_end;
545 	hfp = mode->hsync_start - mode->hdisplay;
546 	hsw = mode->hsync_end - mode->hsync_start;
547 	vbp = mode->vtotal - mode->vsync_end;
548 	vfp = mode->vsync_start - mode->vdisplay;
549 	vsw = mode->vsync_end - mode->vsync_start;
550 
551 	if ((hbp-1) & ~0x3ff) {
552 		DBG("Pruning mode: Horizontal Back Porch out of range");
553 		return MODE_HBLANK_WIDE;
554 	}
555 
556 	if ((hfp-1) & ~0x3ff) {
557 		DBG("Pruning mode: Horizontal Front Porch out of range");
558 		return MODE_HBLANK_WIDE;
559 	}
560 
561 	if ((hsw-1) & ~0x3ff) {
562 		DBG("Pruning mode: Horizontal Sync Width out of range");
563 		return MODE_HSYNC_WIDE;
564 	}
565 
566 	if (vbp & ~0xff) {
567 		DBG("Pruning mode: Vertical Back Porch out of range");
568 		return MODE_VBLANK_WIDE;
569 	}
570 
571 	if (vfp & ~0xff) {
572 		DBG("Pruning mode: Vertical Front Porch out of range");
573 		return MODE_VBLANK_WIDE;
574 	}
575 
576 	if ((vsw-1) & ~0x3f) {
577 		DBG("Pruning mode: Vertical Sync Width out of range");
578 		return MODE_VSYNC_WIDE;
579 	}
580 
581 	/*
582 	 * some devices have a maximum allowed pixel clock
583 	 * configured from the DT
584 	 */
585 	if (mode->clock > priv->max_pixelclock) {
586 		DBG("Pruning mode: pixel clock too high");
587 		return MODE_CLOCK_HIGH;
588 	}
589 
590 	/*
591 	 * some devices further limit the max horizontal resolution
592 	 * configured from the DT
593 	 */
594 	if (mode->hdisplay > priv->max_width)
595 		return MODE_BAD_WIDTH;
596 
597 	/* filter out modes that would require too much memory bandwidth: */
598 	bandwidth = mode->hdisplay * mode->vdisplay *
599 		drm_mode_vrefresh(mode);
600 	if (bandwidth > priv->max_bandwidth) {
601 		DBG("Pruning mode: exceeds defined bandwidth limit");
602 		return MODE_BAD;
603 	}
604 
605 	return MODE_OK;
606 }
607 
608 void tilcdc_crtc_set_panel_info(struct drm_crtc *crtc,
609 		const struct tilcdc_panel_info *info)
610 {
611 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
612 	tilcdc_crtc->info = info;
613 }
614 
615 void tilcdc_crtc_set_simulate_vesa_sync(struct drm_crtc *crtc,
616 					bool simulate_vesa_sync)
617 {
618 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
619 
620 	tilcdc_crtc->simulate_vesa_sync = simulate_vesa_sync;
621 }
622 
623 void tilcdc_crtc_update_clk(struct drm_crtc *crtc)
624 {
625 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
626 	struct drm_device *dev = crtc->dev;
627 	struct tilcdc_drm_private *priv = dev->dev_private;
628 	int dpms = tilcdc_crtc->dpms;
629 	unsigned long lcd_clk;
630 	const unsigned clkdiv = 2; /* using a fixed divider of 2 */
631 	int ret;
632 
633 	pm_runtime_get_sync(dev->dev);
634 
635 	if (dpms == DRM_MODE_DPMS_ON)
636 		tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
637 
638 	/* mode.clock is in KHz, set_rate wants parameter in Hz */
639 	ret = clk_set_rate(priv->clk, crtc->mode.clock * 1000 * clkdiv);
640 	if (ret < 0) {
641 		dev_err(dev->dev, "failed to set display clock rate to: %d\n",
642 				crtc->mode.clock);
643 		goto out;
644 	}
645 
646 	lcd_clk = clk_get_rate(priv->clk);
647 
648 	DBG("lcd_clk=%lu, mode clock=%d, div=%u",
649 		lcd_clk, crtc->mode.clock, clkdiv);
650 
651 	/* Configure the LCD clock divisor. */
652 	tilcdc_write(dev, LCDC_CTRL_REG, LCDC_CLK_DIVISOR(clkdiv) |
653 			LCDC_RASTER_MODE);
654 
655 	if (priv->rev == 2)
656 		tilcdc_set(dev, LCDC_CLK_ENABLE_REG,
657 				LCDC_V2_DMA_CLK_EN | LCDC_V2_LIDD_CLK_EN |
658 				LCDC_V2_CORE_CLK_EN);
659 
660 	if (dpms == DRM_MODE_DPMS_ON)
661 		tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_ON);
662 
663 out:
664 	pm_runtime_put_sync(dev->dev);
665 }
666 
667 #define SYNC_LOST_COUNT_LIMIT 50
668 
669 irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
670 {
671 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
672 	struct drm_device *dev = crtc->dev;
673 	struct tilcdc_drm_private *priv = dev->dev_private;
674 	uint32_t stat;
675 
676 	stat = tilcdc_read_irqstatus(dev);
677 	tilcdc_clear_irqstatus(dev, stat);
678 
679 	if (stat & LCDC_END_OF_FRAME0) {
680 		unsigned long flags;
681 		bool skip_event = false;
682 		ktime_t now;
683 
684 		now = ktime_get();
685 
686 		drm_flip_work_commit(&tilcdc_crtc->unref_work, priv->wq);
687 
688 		spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
689 
690 		tilcdc_crtc->last_vblank = now;
691 
692 		if (tilcdc_crtc->next_fb) {
693 			set_scanout(crtc, tilcdc_crtc->next_fb);
694 			tilcdc_crtc->next_fb = NULL;
695 			skip_event = true;
696 		}
697 
698 		spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
699 
700 		drm_crtc_handle_vblank(crtc);
701 
702 		if (!skip_event) {
703 			struct drm_pending_vblank_event *event;
704 
705 			spin_lock_irqsave(&dev->event_lock, flags);
706 
707 			event = tilcdc_crtc->event;
708 			tilcdc_crtc->event = NULL;
709 			if (event)
710 				drm_crtc_send_vblank_event(crtc, event);
711 
712 			spin_unlock_irqrestore(&dev->event_lock, flags);
713 		}
714 
715 		if (tilcdc_crtc->frame_intact)
716 			tilcdc_crtc->sync_lost_count = 0;
717 		else
718 			tilcdc_crtc->frame_intact = true;
719 	}
720 
721 	if (priv->rev == 2) {
722 		if (stat & LCDC_FRAME_DONE) {
723 			tilcdc_crtc->frame_done = true;
724 			wake_up(&tilcdc_crtc->frame_done_wq);
725 		}
726 		tilcdc_write(dev, LCDC_END_OF_INT_IND_REG, 0);
727 	}
728 
729 	if (stat & LCDC_SYNC_LOST) {
730 		dev_err_ratelimited(dev->dev, "%s(0x%08x): Sync lost",
731 				    __func__, stat);
732 		tilcdc_crtc->frame_intact = false;
733 		if (tilcdc_crtc->sync_lost_count++ > SYNC_LOST_COUNT_LIMIT) {
734 			dev_err(dev->dev,
735 				"%s(0x%08x): Sync lost flood detected, disabling the interrupt",
736 				__func__, stat);
737 			tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
738 				     LCDC_SYNC_LOST);
739 		}
740 	}
741 
742 	if (stat & LCDC_FIFO_UNDERFLOW)
743 		dev_err_ratelimited(dev->dev, "%s(0x%08x): FIFO underfow",
744 				    __func__, stat);
745 
746 	return IRQ_HANDLED;
747 }
748 
749 struct drm_crtc *tilcdc_crtc_create(struct drm_device *dev)
750 {
751 	struct tilcdc_drm_private *priv = dev->dev_private;
752 	struct tilcdc_crtc *tilcdc_crtc;
753 	struct drm_crtc *crtc;
754 	int ret;
755 
756 	tilcdc_crtc = devm_kzalloc(dev->dev, sizeof(*tilcdc_crtc), GFP_KERNEL);
757 	if (!tilcdc_crtc) {
758 		dev_err(dev->dev, "allocation failed\n");
759 		return NULL;
760 	}
761 
762 	crtc = &tilcdc_crtc->base;
763 
764 	tilcdc_crtc->dpms = DRM_MODE_DPMS_OFF;
765 	init_waitqueue_head(&tilcdc_crtc->frame_done_wq);
766 
767 	drm_flip_work_init(&tilcdc_crtc->unref_work,
768 			"unref", unref_worker);
769 
770 	spin_lock_init(&tilcdc_crtc->irq_lock);
771 
772 	ret = drm_crtc_init(dev, crtc, &tilcdc_crtc_funcs);
773 	if (ret < 0)
774 		goto fail;
775 
776 	drm_crtc_helper_add(crtc, &tilcdc_crtc_helper_funcs);
777 
778 	if (priv->is_componentized) {
779 		struct device_node *ports =
780 			of_get_child_by_name(dev->dev->of_node, "ports");
781 
782 		if (ports) {
783 			crtc->port = of_get_child_by_name(ports, "port");
784 			of_node_put(ports);
785 		} else {
786 			crtc->port =
787 				of_get_child_by_name(dev->dev->of_node, "port");
788 		}
789 		if (!crtc->port) { /* This should never happen */
790 			dev_err(dev->dev, "Port node not found in %s\n",
791 				dev->dev->of_node->full_name);
792 			goto fail;
793 		}
794 	}
795 
796 	return crtc;
797 
798 fail:
799 	tilcdc_crtc_destroy(crtc);
800 	return NULL;
801 }
802