1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2012 Texas Instruments
4  * Author: Rob Clark <robdclark@gmail.com>
5  */
6 
7 #include <linux/delay.h>
8 #include <linux/dma-mapping.h>
9 #include <linux/of_graph.h>
10 #include <linux/pm_runtime.h>
11 
12 #include <drm/drm_atomic.h>
13 #include <drm/drm_atomic_helper.h>
14 #include <drm/drm_crtc.h>
15 #include <drm/drm_fb_cma_helper.h>
16 #include <drm/drm_fourcc.h>
17 #include <drm/drm_gem_cma_helper.h>
18 #include <drm/drm_modeset_helper_vtables.h>
19 #include <drm/drm_print.h>
20 #include <drm/drm_vblank.h>
21 
22 #include "tilcdc_drv.h"
23 #include "tilcdc_regs.h"
24 
25 #define TILCDC_VBLANK_SAFETY_THRESHOLD_US	1000
26 #define TILCDC_PALETTE_SIZE			32
27 #define TILCDC_PALETTE_FIRST_ENTRY		0x4000
28 
29 struct tilcdc_crtc {
30 	struct drm_crtc base;
31 
32 	struct drm_plane primary;
33 	const struct tilcdc_panel_info *info;
34 	struct drm_pending_vblank_event *event;
35 	struct mutex enable_lock;
36 	bool enabled;
37 	bool shutdown;
38 	wait_queue_head_t frame_done_wq;
39 	bool frame_done;
40 	spinlock_t irq_lock;
41 
42 	unsigned int lcd_fck_rate;
43 
44 	ktime_t last_vblank;
45 	unsigned int hvtotal_us;
46 
47 	struct drm_framebuffer *next_fb;
48 
49 	/* Only set if an external encoder is connected */
50 	bool simulate_vesa_sync;
51 
52 	int sync_lost_count;
53 	bool frame_intact;
54 	struct work_struct recover_work;
55 
56 	dma_addr_t palette_dma_handle;
57 	u16 *palette_base;
58 	struct completion palette_loaded;
59 };
60 #define to_tilcdc_crtc(x) container_of(x, struct tilcdc_crtc, base)
61 
62 static void set_scanout(struct drm_crtc *crtc, struct drm_framebuffer *fb)
63 {
64 	struct drm_device *dev = crtc->dev;
65 	struct tilcdc_drm_private *priv = dev->dev_private;
66 	struct drm_gem_cma_object *gem;
67 	dma_addr_t start, end;
68 	u64 dma_base_and_ceiling;
69 
70 	gem = drm_fb_cma_get_gem_obj(fb, 0);
71 
72 	start = gem->paddr + fb->offsets[0] +
73 		crtc->y * fb->pitches[0] +
74 		crtc->x * fb->format->cpp[0];
75 
76 	end = start + (crtc->mode.vdisplay * fb->pitches[0]);
77 
78 	/* Write LCDC_DMA_FB_BASE_ADDR_0_REG and LCDC_DMA_FB_CEILING_ADDR_0_REG
79 	 * with a single insruction, if available. This should make it more
80 	 * unlikely that LCDC would fetch the DMA addresses in the middle of
81 	 * an update.
82 	 */
83 	if (priv->rev == 1)
84 		end -= 1;
85 
86 	dma_base_and_ceiling = (u64)end << 32 | start;
87 	tilcdc_write64(dev, LCDC_DMA_FB_BASE_ADDR_0_REG, dma_base_and_ceiling);
88 }
89 
90 /*
91  * The driver currently only supports only true color formats. For
92  * true color the palette block is bypassed, but a 32 byte palette
93  * should still be loaded. The first 16-bit entry must be 0x4000 while
94  * all other entries must be zeroed.
95  */
96 static void tilcdc_crtc_load_palette(struct drm_crtc *crtc)
97 {
98 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
99 	struct drm_device *dev = crtc->dev;
100 	struct tilcdc_drm_private *priv = dev->dev_private;
101 	int ret;
102 
103 	reinit_completion(&tilcdc_crtc->palette_loaded);
104 
105 	/* Tell the LCDC where the palette is located. */
106 	tilcdc_write(dev, LCDC_DMA_FB_BASE_ADDR_0_REG,
107 		     tilcdc_crtc->palette_dma_handle);
108 	tilcdc_write(dev, LCDC_DMA_FB_CEILING_ADDR_0_REG,
109 		     (u32) tilcdc_crtc->palette_dma_handle +
110 		     TILCDC_PALETTE_SIZE - 1);
111 
112 	/* Set dma load mode for palette loading only. */
113 	tilcdc_write_mask(dev, LCDC_RASTER_CTRL_REG,
114 			  LCDC_PALETTE_LOAD_MODE(PALETTE_ONLY),
115 			  LCDC_PALETTE_LOAD_MODE_MASK);
116 
117 	/* Enable DMA Palette Loaded Interrupt */
118 	if (priv->rev == 1)
119 		tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_V1_PL_INT_ENA);
120 	else
121 		tilcdc_write(dev, LCDC_INT_ENABLE_SET_REG, LCDC_V2_PL_INT_ENA);
122 
123 	/* Enable LCDC DMA and wait for palette to be loaded. */
124 	tilcdc_clear_irqstatus(dev, 0xffffffff);
125 	tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
126 
127 	ret = wait_for_completion_timeout(&tilcdc_crtc->palette_loaded,
128 					  msecs_to_jiffies(50));
129 	if (ret == 0)
130 		dev_err(dev->dev, "%s: Palette loading timeout", __func__);
131 
132 	/* Disable LCDC DMA and DMA Palette Loaded Interrupt. */
133 	tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
134 	if (priv->rev == 1)
135 		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_V1_PL_INT_ENA);
136 	else
137 		tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG, LCDC_V2_PL_INT_ENA);
138 }
139 
140 static void tilcdc_crtc_enable_irqs(struct drm_device *dev)
141 {
142 	struct tilcdc_drm_private *priv = dev->dev_private;
143 
144 	tilcdc_clear_irqstatus(dev, 0xffffffff);
145 
146 	if (priv->rev == 1) {
147 		tilcdc_set(dev, LCDC_RASTER_CTRL_REG,
148 			LCDC_V1_SYNC_LOST_INT_ENA | LCDC_V1_FRAME_DONE_INT_ENA |
149 			LCDC_V1_UNDERFLOW_INT_ENA);
150 		tilcdc_set(dev, LCDC_DMA_CTRL_REG,
151 			LCDC_V1_END_OF_FRAME_INT_ENA);
152 	} else {
153 		tilcdc_write(dev, LCDC_INT_ENABLE_SET_REG,
154 			LCDC_V2_UNDERFLOW_INT_ENA |
155 			LCDC_V2_END_OF_FRAME0_INT_ENA |
156 			LCDC_FRAME_DONE | LCDC_SYNC_LOST);
157 	}
158 }
159 
160 static void tilcdc_crtc_disable_irqs(struct drm_device *dev)
161 {
162 	struct tilcdc_drm_private *priv = dev->dev_private;
163 
164 	/* disable irqs that we might have enabled: */
165 	if (priv->rev == 1) {
166 		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
167 			LCDC_V1_SYNC_LOST_INT_ENA | LCDC_V1_FRAME_DONE_INT_ENA |
168 			LCDC_V1_UNDERFLOW_INT_ENA | LCDC_V1_PL_INT_ENA);
169 		tilcdc_clear(dev, LCDC_DMA_CTRL_REG,
170 			LCDC_V1_END_OF_FRAME_INT_ENA);
171 	} else {
172 		tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
173 			LCDC_V2_UNDERFLOW_INT_ENA | LCDC_V2_PL_INT_ENA |
174 			LCDC_V2_END_OF_FRAME0_INT_ENA |
175 			LCDC_FRAME_DONE | LCDC_SYNC_LOST);
176 	}
177 }
178 
179 static void reset(struct drm_crtc *crtc)
180 {
181 	struct drm_device *dev = crtc->dev;
182 	struct tilcdc_drm_private *priv = dev->dev_private;
183 
184 	if (priv->rev != 2)
185 		return;
186 
187 	tilcdc_set(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
188 	usleep_range(250, 1000);
189 	tilcdc_clear(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
190 }
191 
192 /*
193  * Calculate the percentage difference between the requested pixel clock rate
194  * and the effective rate resulting from calculating the clock divider value.
195  */
196 static unsigned int tilcdc_pclk_diff(unsigned long rate,
197 				     unsigned long real_rate)
198 {
199 	int r = rate / 100, rr = real_rate / 100;
200 
201 	return (unsigned int)(abs(((rr - r) * 100) / r));
202 }
203 
204 static void tilcdc_crtc_set_clk(struct drm_crtc *crtc)
205 {
206 	struct drm_device *dev = crtc->dev;
207 	struct tilcdc_drm_private *priv = dev->dev_private;
208 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
209 	unsigned long clk_rate, real_rate, req_rate;
210 	unsigned int clkdiv;
211 	int ret;
212 
213 	clkdiv = 2; /* first try using a standard divider of 2 */
214 
215 	/* mode.clock is in KHz, set_rate wants parameter in Hz */
216 	req_rate = crtc->mode.clock * 1000;
217 
218 	ret = clk_set_rate(priv->clk, req_rate * clkdiv);
219 	clk_rate = clk_get_rate(priv->clk);
220 	if (ret < 0 || tilcdc_pclk_diff(req_rate, clk_rate) > 5) {
221 		/*
222 		 * If we fail to set the clock rate (some architectures don't
223 		 * use the common clock framework yet and may not implement
224 		 * all the clk API calls for every clock), try the next best
225 		 * thing: adjusting the clock divider, unless clk_get_rate()
226 		 * failed as well.
227 		 */
228 		if (!clk_rate) {
229 			/* Nothing more we can do. Just bail out. */
230 			dev_err(dev->dev,
231 				"failed to set the pixel clock - unable to read current lcdc clock rate\n");
232 			return;
233 		}
234 
235 		clkdiv = DIV_ROUND_CLOSEST(clk_rate, req_rate);
236 
237 		/*
238 		 * Emit a warning if the real clock rate resulting from the
239 		 * calculated divider differs much from the requested rate.
240 		 *
241 		 * 5% is an arbitrary value - LCDs are usually quite tolerant
242 		 * about pixel clock rates.
243 		 */
244 		real_rate = clkdiv * req_rate;
245 
246 		if (tilcdc_pclk_diff(clk_rate, real_rate) > 5) {
247 			dev_warn(dev->dev,
248 				 "effective pixel clock rate (%luHz) differs from the calculated rate (%luHz)\n",
249 				 clk_rate, real_rate);
250 		}
251 	}
252 
253 	tilcdc_crtc->lcd_fck_rate = clk_rate;
254 
255 	DBG("lcd_clk=%u, mode clock=%d, div=%u",
256 	    tilcdc_crtc->lcd_fck_rate, crtc->mode.clock, clkdiv);
257 
258 	/* Configure the LCD clock divisor. */
259 	tilcdc_write(dev, LCDC_CTRL_REG, LCDC_CLK_DIVISOR(clkdiv) |
260 		     LCDC_RASTER_MODE);
261 
262 	if (priv->rev == 2)
263 		tilcdc_set(dev, LCDC_CLK_ENABLE_REG,
264 				LCDC_V2_DMA_CLK_EN | LCDC_V2_LIDD_CLK_EN |
265 				LCDC_V2_CORE_CLK_EN);
266 }
267 
268 static uint tilcdc_mode_hvtotal(const struct drm_display_mode *mode)
269 {
270 	return (uint) div_u64(1000llu * mode->htotal * mode->vtotal,
271 			      mode->clock);
272 }
273 
274 static void tilcdc_crtc_set_mode(struct drm_crtc *crtc)
275 {
276 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
277 	struct drm_device *dev = crtc->dev;
278 	struct tilcdc_drm_private *priv = dev->dev_private;
279 	const struct tilcdc_panel_info *info = tilcdc_crtc->info;
280 	uint32_t reg, hbp, hfp, hsw, vbp, vfp, vsw;
281 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
282 	struct drm_framebuffer *fb = crtc->primary->state->fb;
283 
284 	if (WARN_ON(!info))
285 		return;
286 
287 	if (WARN_ON(!fb))
288 		return;
289 
290 	/* Configure the Burst Size and fifo threshold of DMA: */
291 	reg = tilcdc_read(dev, LCDC_DMA_CTRL_REG) & ~0x00000770;
292 	switch (info->dma_burst_sz) {
293 	case 1:
294 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_1);
295 		break;
296 	case 2:
297 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_2);
298 		break;
299 	case 4:
300 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_4);
301 		break;
302 	case 8:
303 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_8);
304 		break;
305 	case 16:
306 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_16);
307 		break;
308 	default:
309 		dev_err(dev->dev, "invalid burst size\n");
310 		return;
311 	}
312 	reg |= (info->fifo_th << 8);
313 	tilcdc_write(dev, LCDC_DMA_CTRL_REG, reg);
314 
315 	/* Configure timings: */
316 	hbp = mode->htotal - mode->hsync_end;
317 	hfp = mode->hsync_start - mode->hdisplay;
318 	hsw = mode->hsync_end - mode->hsync_start;
319 	vbp = mode->vtotal - mode->vsync_end;
320 	vfp = mode->vsync_start - mode->vdisplay;
321 	vsw = mode->vsync_end - mode->vsync_start;
322 
323 	DBG("%dx%d, hbp=%u, hfp=%u, hsw=%u, vbp=%u, vfp=%u, vsw=%u",
324 	    mode->hdisplay, mode->vdisplay, hbp, hfp, hsw, vbp, vfp, vsw);
325 
326 	/* Set AC Bias Period and Number of Transitions per Interrupt: */
327 	reg = tilcdc_read(dev, LCDC_RASTER_TIMING_2_REG) & ~0x000fff00;
328 	reg |= LCDC_AC_BIAS_FREQUENCY(info->ac_bias) |
329 		LCDC_AC_BIAS_TRANSITIONS_PER_INT(info->ac_bias_intrpt);
330 
331 	/*
332 	 * subtract one from hfp, hbp, hsw because the hardware uses
333 	 * a value of 0 as 1
334 	 */
335 	if (priv->rev == 2) {
336 		/* clear bits we're going to set */
337 		reg &= ~0x78000033;
338 		reg |= ((hfp-1) & 0x300) >> 8;
339 		reg |= ((hbp-1) & 0x300) >> 4;
340 		reg |= ((hsw-1) & 0x3c0) << 21;
341 	}
342 	tilcdc_write(dev, LCDC_RASTER_TIMING_2_REG, reg);
343 
344 	reg = (((mode->hdisplay >> 4) - 1) << 4) |
345 		(((hbp-1) & 0xff) << 24) |
346 		(((hfp-1) & 0xff) << 16) |
347 		(((hsw-1) & 0x3f) << 10);
348 	if (priv->rev == 2)
349 		reg |= (((mode->hdisplay >> 4) - 1) & 0x40) >> 3;
350 	tilcdc_write(dev, LCDC_RASTER_TIMING_0_REG, reg);
351 
352 	reg = ((mode->vdisplay - 1) & 0x3ff) |
353 		((vbp & 0xff) << 24) |
354 		((vfp & 0xff) << 16) |
355 		(((vsw-1) & 0x3f) << 10);
356 	tilcdc_write(dev, LCDC_RASTER_TIMING_1_REG, reg);
357 
358 	/*
359 	 * be sure to set Bit 10 for the V2 LCDC controller,
360 	 * otherwise limited to 1024 pixels width, stopping
361 	 * 1920x1080 being supported.
362 	 */
363 	if (priv->rev == 2) {
364 		if ((mode->vdisplay - 1) & 0x400) {
365 			tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG,
366 				LCDC_LPP_B10);
367 		} else {
368 			tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG,
369 				LCDC_LPP_B10);
370 		}
371 	}
372 
373 	/* Configure display type: */
374 	reg = tilcdc_read(dev, LCDC_RASTER_CTRL_REG) &
375 		~(LCDC_TFT_MODE | LCDC_MONO_8BIT_MODE | LCDC_MONOCHROME_MODE |
376 		  LCDC_V2_TFT_24BPP_MODE | LCDC_V2_TFT_24BPP_UNPACK |
377 		  0x000ff000 /* Palette Loading Delay bits */);
378 	reg |= LCDC_TFT_MODE; /* no monochrome/passive support */
379 	if (info->tft_alt_mode)
380 		reg |= LCDC_TFT_ALT_ENABLE;
381 	if (priv->rev == 2) {
382 		switch (fb->format->format) {
383 		case DRM_FORMAT_BGR565:
384 		case DRM_FORMAT_RGB565:
385 			break;
386 		case DRM_FORMAT_XBGR8888:
387 		case DRM_FORMAT_XRGB8888:
388 			reg |= LCDC_V2_TFT_24BPP_UNPACK;
389 			/* fallthrough */
390 		case DRM_FORMAT_BGR888:
391 		case DRM_FORMAT_RGB888:
392 			reg |= LCDC_V2_TFT_24BPP_MODE;
393 			break;
394 		default:
395 			dev_err(dev->dev, "invalid pixel format\n");
396 			return;
397 		}
398 	}
399 	reg |= info->fdd < 12;
400 	tilcdc_write(dev, LCDC_RASTER_CTRL_REG, reg);
401 
402 	if (info->invert_pxl_clk)
403 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_PIXEL_CLOCK);
404 	else
405 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_PIXEL_CLOCK);
406 
407 	if (info->sync_ctrl)
408 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_CTRL);
409 	else
410 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_CTRL);
411 
412 	if (info->sync_edge)
413 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);
414 	else
415 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);
416 
417 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
418 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC);
419 	else
420 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC);
421 
422 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
423 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_VSYNC);
424 	else
425 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_VSYNC);
426 
427 	if (info->raster_order)
428 		tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ORDER);
429 	else
430 		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ORDER);
431 
432 	tilcdc_crtc_set_clk(crtc);
433 
434 	tilcdc_crtc_load_palette(crtc);
435 
436 	set_scanout(crtc, fb);
437 
438 	crtc->hwmode = crtc->state->adjusted_mode;
439 
440 	tilcdc_crtc->hvtotal_us =
441 		tilcdc_mode_hvtotal(&crtc->hwmode);
442 }
443 
444 static void tilcdc_crtc_enable(struct drm_crtc *crtc)
445 {
446 	struct drm_device *dev = crtc->dev;
447 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
448 	unsigned long flags;
449 
450 	mutex_lock(&tilcdc_crtc->enable_lock);
451 	if (tilcdc_crtc->enabled || tilcdc_crtc->shutdown) {
452 		mutex_unlock(&tilcdc_crtc->enable_lock);
453 		return;
454 	}
455 
456 	pm_runtime_get_sync(dev->dev);
457 
458 	reset(crtc);
459 
460 	tilcdc_crtc_set_mode(crtc);
461 
462 	tilcdc_crtc_enable_irqs(dev);
463 
464 	tilcdc_clear(dev, LCDC_DMA_CTRL_REG, LCDC_DUAL_FRAME_BUFFER_ENABLE);
465 	tilcdc_write_mask(dev, LCDC_RASTER_CTRL_REG,
466 			  LCDC_PALETTE_LOAD_MODE(DATA_ONLY),
467 			  LCDC_PALETTE_LOAD_MODE_MASK);
468 
469 	/* There is no real chance for a race here as the time stamp
470 	 * is taken before the raster DMA is started. The spin-lock is
471 	 * taken to have a memory barrier after taking the time-stamp
472 	 * and to avoid a context switch between taking the stamp and
473 	 * enabling the raster.
474 	 */
475 	spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
476 	tilcdc_crtc->last_vblank = ktime_get();
477 	tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
478 	spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
479 
480 	drm_crtc_vblank_on(crtc);
481 
482 	tilcdc_crtc->enabled = true;
483 	mutex_unlock(&tilcdc_crtc->enable_lock);
484 }
485 
486 static void tilcdc_crtc_atomic_enable(struct drm_crtc *crtc,
487 				      struct drm_crtc_state *old_state)
488 {
489 	tilcdc_crtc_enable(crtc);
490 }
491 
492 static void tilcdc_crtc_off(struct drm_crtc *crtc, bool shutdown)
493 {
494 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
495 	struct drm_device *dev = crtc->dev;
496 	int ret;
497 
498 	mutex_lock(&tilcdc_crtc->enable_lock);
499 	if (shutdown)
500 		tilcdc_crtc->shutdown = true;
501 	if (!tilcdc_crtc->enabled) {
502 		mutex_unlock(&tilcdc_crtc->enable_lock);
503 		return;
504 	}
505 	tilcdc_crtc->frame_done = false;
506 	tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
507 
508 	/*
509 	 * Wait for framedone irq which will still come before putting
510 	 * things to sleep..
511 	 */
512 	ret = wait_event_timeout(tilcdc_crtc->frame_done_wq,
513 				 tilcdc_crtc->frame_done,
514 				 msecs_to_jiffies(500));
515 	if (ret == 0)
516 		dev_err(dev->dev, "%s: timeout waiting for framedone\n",
517 			__func__);
518 
519 	drm_crtc_vblank_off(crtc);
520 
521 	tilcdc_crtc_disable_irqs(dev);
522 
523 	pm_runtime_put_sync(dev->dev);
524 
525 	tilcdc_crtc->enabled = false;
526 	mutex_unlock(&tilcdc_crtc->enable_lock);
527 }
528 
529 static void tilcdc_crtc_disable(struct drm_crtc *crtc)
530 {
531 	tilcdc_crtc_off(crtc, false);
532 }
533 
534 static void tilcdc_crtc_atomic_disable(struct drm_crtc *crtc,
535 				       struct drm_crtc_state *old_state)
536 {
537 	tilcdc_crtc_disable(crtc);
538 }
539 
540 void tilcdc_crtc_shutdown(struct drm_crtc *crtc)
541 {
542 	tilcdc_crtc_off(crtc, true);
543 }
544 
545 static bool tilcdc_crtc_is_on(struct drm_crtc *crtc)
546 {
547 	return crtc->state && crtc->state->enable && crtc->state->active;
548 }
549 
550 static void tilcdc_crtc_recover_work(struct work_struct *work)
551 {
552 	struct tilcdc_crtc *tilcdc_crtc =
553 		container_of(work, struct tilcdc_crtc, recover_work);
554 	struct drm_crtc *crtc = &tilcdc_crtc->base;
555 
556 	dev_info(crtc->dev->dev, "%s: Reset CRTC", __func__);
557 
558 	drm_modeset_lock(&crtc->mutex, NULL);
559 
560 	if (!tilcdc_crtc_is_on(crtc))
561 		goto out;
562 
563 	tilcdc_crtc_disable(crtc);
564 	tilcdc_crtc_enable(crtc);
565 out:
566 	drm_modeset_unlock(&crtc->mutex);
567 }
568 
569 static void tilcdc_crtc_destroy(struct drm_crtc *crtc)
570 {
571 	struct tilcdc_drm_private *priv = crtc->dev->dev_private;
572 
573 	tilcdc_crtc_shutdown(crtc);
574 
575 	flush_workqueue(priv->wq);
576 
577 	of_node_put(crtc->port);
578 	drm_crtc_cleanup(crtc);
579 }
580 
581 int tilcdc_crtc_update_fb(struct drm_crtc *crtc,
582 		struct drm_framebuffer *fb,
583 		struct drm_pending_vblank_event *event)
584 {
585 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
586 	struct drm_device *dev = crtc->dev;
587 
588 	if (tilcdc_crtc->event) {
589 		dev_err(dev->dev, "already pending page flip!\n");
590 		return -EBUSY;
591 	}
592 
593 	tilcdc_crtc->event = event;
594 
595 	mutex_lock(&tilcdc_crtc->enable_lock);
596 
597 	if (tilcdc_crtc->enabled) {
598 		unsigned long flags;
599 		ktime_t next_vblank;
600 		s64 tdiff;
601 
602 		spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
603 
604 		next_vblank = ktime_add_us(tilcdc_crtc->last_vblank,
605 					   tilcdc_crtc->hvtotal_us);
606 		tdiff = ktime_to_us(ktime_sub(next_vblank, ktime_get()));
607 
608 		if (tdiff < TILCDC_VBLANK_SAFETY_THRESHOLD_US)
609 			tilcdc_crtc->next_fb = fb;
610 		else
611 			set_scanout(crtc, fb);
612 
613 		spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
614 	}
615 
616 	mutex_unlock(&tilcdc_crtc->enable_lock);
617 
618 	return 0;
619 }
620 
621 static bool tilcdc_crtc_mode_fixup(struct drm_crtc *crtc,
622 		const struct drm_display_mode *mode,
623 		struct drm_display_mode *adjusted_mode)
624 {
625 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
626 
627 	if (!tilcdc_crtc->simulate_vesa_sync)
628 		return true;
629 
630 	/*
631 	 * tilcdc does not generate VESA-compliant sync but aligns
632 	 * VS on the second edge of HS instead of first edge.
633 	 * We use adjusted_mode, to fixup sync by aligning both rising
634 	 * edges and add HSKEW offset to fix the sync.
635 	 */
636 	adjusted_mode->hskew = mode->hsync_end - mode->hsync_start;
637 	adjusted_mode->flags |= DRM_MODE_FLAG_HSKEW;
638 
639 	if (mode->flags & DRM_MODE_FLAG_NHSYNC) {
640 		adjusted_mode->flags |= DRM_MODE_FLAG_PHSYNC;
641 		adjusted_mode->flags &= ~DRM_MODE_FLAG_NHSYNC;
642 	} else {
643 		adjusted_mode->flags |= DRM_MODE_FLAG_NHSYNC;
644 		adjusted_mode->flags &= ~DRM_MODE_FLAG_PHSYNC;
645 	}
646 
647 	return true;
648 }
649 
650 static int tilcdc_crtc_atomic_check(struct drm_crtc *crtc,
651 				    struct drm_crtc_state *state)
652 {
653 	/* If we are not active we don't care */
654 	if (!state->active)
655 		return 0;
656 
657 	if (state->state->planes[0].ptr != crtc->primary ||
658 	    state->state->planes[0].state == NULL ||
659 	    state->state->planes[0].state->crtc != crtc) {
660 		dev_dbg(crtc->dev->dev, "CRTC primary plane must be present");
661 		return -EINVAL;
662 	}
663 
664 	return 0;
665 }
666 
667 static int tilcdc_crtc_enable_vblank(struct drm_crtc *crtc)
668 {
669 	return 0;
670 }
671 
672 static void tilcdc_crtc_disable_vblank(struct drm_crtc *crtc)
673 {
674 }
675 
676 static void tilcdc_crtc_reset(struct drm_crtc *crtc)
677 {
678 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
679 	struct drm_device *dev = crtc->dev;
680 	int ret;
681 
682 	drm_atomic_helper_crtc_reset(crtc);
683 
684 	/* Turn the raster off if it for some reason is on. */
685 	pm_runtime_get_sync(dev->dev);
686 	if (tilcdc_read(dev, LCDC_RASTER_CTRL_REG) & LCDC_RASTER_ENABLE) {
687 		/* Enable DMA Frame Done Interrupt */
688 		tilcdc_write(dev, LCDC_INT_ENABLE_SET_REG, LCDC_FRAME_DONE);
689 		tilcdc_clear_irqstatus(dev, 0xffffffff);
690 
691 		tilcdc_crtc->frame_done = false;
692 		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
693 
694 		ret = wait_event_timeout(tilcdc_crtc->frame_done_wq,
695 					 tilcdc_crtc->frame_done,
696 					 msecs_to_jiffies(500));
697 		if (ret == 0)
698 			dev_err(dev->dev, "%s: timeout waiting for framedone\n",
699 				__func__);
700 	}
701 	pm_runtime_put_sync(dev->dev);
702 }
703 
704 static const struct drm_crtc_funcs tilcdc_crtc_funcs = {
705 	.destroy        = tilcdc_crtc_destroy,
706 	.set_config     = drm_atomic_helper_set_config,
707 	.page_flip      = drm_atomic_helper_page_flip,
708 	.reset		= tilcdc_crtc_reset,
709 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
710 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
711 	.enable_vblank	= tilcdc_crtc_enable_vblank,
712 	.disable_vblank	= tilcdc_crtc_disable_vblank,
713 };
714 
715 int tilcdc_crtc_max_width(struct drm_crtc *crtc)
716 {
717 	struct drm_device *dev = crtc->dev;
718 	struct tilcdc_drm_private *priv = dev->dev_private;
719 	int max_width = 0;
720 
721 	if (priv->rev == 1)
722 		max_width = 1024;
723 	else if (priv->rev == 2)
724 		max_width = 2048;
725 
726 	return max_width;
727 }
728 
729 static enum drm_mode_status
730 tilcdc_crtc_mode_valid(struct drm_crtc *crtc,
731 		       const struct drm_display_mode *mode)
732 {
733 	struct tilcdc_drm_private *priv = crtc->dev->dev_private;
734 	unsigned int bandwidth;
735 	uint32_t hbp, hfp, hsw, vbp, vfp, vsw;
736 
737 	/*
738 	 * check to see if the width is within the range that
739 	 * the LCD Controller physically supports
740 	 */
741 	if (mode->hdisplay > tilcdc_crtc_max_width(crtc))
742 		return MODE_VIRTUAL_X;
743 
744 	/* width must be multiple of 16 */
745 	if (mode->hdisplay & 0xf)
746 		return MODE_VIRTUAL_X;
747 
748 	if (mode->vdisplay > 2048)
749 		return MODE_VIRTUAL_Y;
750 
751 	DBG("Processing mode %dx%d@%d with pixel clock %d",
752 		mode->hdisplay, mode->vdisplay,
753 		drm_mode_vrefresh(mode), mode->clock);
754 
755 	hbp = mode->htotal - mode->hsync_end;
756 	hfp = mode->hsync_start - mode->hdisplay;
757 	hsw = mode->hsync_end - mode->hsync_start;
758 	vbp = mode->vtotal - mode->vsync_end;
759 	vfp = mode->vsync_start - mode->vdisplay;
760 	vsw = mode->vsync_end - mode->vsync_start;
761 
762 	if ((hbp-1) & ~0x3ff) {
763 		DBG("Pruning mode: Horizontal Back Porch out of range");
764 		return MODE_HBLANK_WIDE;
765 	}
766 
767 	if ((hfp-1) & ~0x3ff) {
768 		DBG("Pruning mode: Horizontal Front Porch out of range");
769 		return MODE_HBLANK_WIDE;
770 	}
771 
772 	if ((hsw-1) & ~0x3ff) {
773 		DBG("Pruning mode: Horizontal Sync Width out of range");
774 		return MODE_HSYNC_WIDE;
775 	}
776 
777 	if (vbp & ~0xff) {
778 		DBG("Pruning mode: Vertical Back Porch out of range");
779 		return MODE_VBLANK_WIDE;
780 	}
781 
782 	if (vfp & ~0xff) {
783 		DBG("Pruning mode: Vertical Front Porch out of range");
784 		return MODE_VBLANK_WIDE;
785 	}
786 
787 	if ((vsw-1) & ~0x3f) {
788 		DBG("Pruning mode: Vertical Sync Width out of range");
789 		return MODE_VSYNC_WIDE;
790 	}
791 
792 	/*
793 	 * some devices have a maximum allowed pixel clock
794 	 * configured from the DT
795 	 */
796 	if (mode->clock > priv->max_pixelclock) {
797 		DBG("Pruning mode: pixel clock too high");
798 		return MODE_CLOCK_HIGH;
799 	}
800 
801 	/*
802 	 * some devices further limit the max horizontal resolution
803 	 * configured from the DT
804 	 */
805 	if (mode->hdisplay > priv->max_width)
806 		return MODE_BAD_WIDTH;
807 
808 	/* filter out modes that would require too much memory bandwidth: */
809 	bandwidth = mode->hdisplay * mode->vdisplay *
810 		drm_mode_vrefresh(mode);
811 	if (bandwidth > priv->max_bandwidth) {
812 		DBG("Pruning mode: exceeds defined bandwidth limit");
813 		return MODE_BAD;
814 	}
815 
816 	return MODE_OK;
817 }
818 
819 static const struct drm_crtc_helper_funcs tilcdc_crtc_helper_funcs = {
820 	.mode_valid	= tilcdc_crtc_mode_valid,
821 	.mode_fixup	= tilcdc_crtc_mode_fixup,
822 	.atomic_check	= tilcdc_crtc_atomic_check,
823 	.atomic_enable	= tilcdc_crtc_atomic_enable,
824 	.atomic_disable	= tilcdc_crtc_atomic_disable,
825 };
826 
827 void tilcdc_crtc_set_panel_info(struct drm_crtc *crtc,
828 		const struct tilcdc_panel_info *info)
829 {
830 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
831 	tilcdc_crtc->info = info;
832 }
833 
834 void tilcdc_crtc_set_simulate_vesa_sync(struct drm_crtc *crtc,
835 					bool simulate_vesa_sync)
836 {
837 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
838 
839 	tilcdc_crtc->simulate_vesa_sync = simulate_vesa_sync;
840 }
841 
842 void tilcdc_crtc_update_clk(struct drm_crtc *crtc)
843 {
844 	struct drm_device *dev = crtc->dev;
845 	struct tilcdc_drm_private *priv = dev->dev_private;
846 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
847 
848 	drm_modeset_lock(&crtc->mutex, NULL);
849 	if (tilcdc_crtc->lcd_fck_rate != clk_get_rate(priv->clk)) {
850 		if (tilcdc_crtc_is_on(crtc)) {
851 			pm_runtime_get_sync(dev->dev);
852 			tilcdc_crtc_disable(crtc);
853 
854 			tilcdc_crtc_set_clk(crtc);
855 
856 			tilcdc_crtc_enable(crtc);
857 			pm_runtime_put_sync(dev->dev);
858 		}
859 	}
860 	drm_modeset_unlock(&crtc->mutex);
861 }
862 
863 #define SYNC_LOST_COUNT_LIMIT 50
864 
865 irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
866 {
867 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
868 	struct drm_device *dev = crtc->dev;
869 	struct tilcdc_drm_private *priv = dev->dev_private;
870 	uint32_t stat, reg;
871 
872 	stat = tilcdc_read_irqstatus(dev);
873 	tilcdc_clear_irqstatus(dev, stat);
874 
875 	if (stat & LCDC_END_OF_FRAME0) {
876 		unsigned long flags;
877 		bool skip_event = false;
878 		ktime_t now;
879 
880 		now = ktime_get();
881 
882 		spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
883 
884 		tilcdc_crtc->last_vblank = now;
885 
886 		if (tilcdc_crtc->next_fb) {
887 			set_scanout(crtc, tilcdc_crtc->next_fb);
888 			tilcdc_crtc->next_fb = NULL;
889 			skip_event = true;
890 		}
891 
892 		spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
893 
894 		drm_crtc_handle_vblank(crtc);
895 
896 		if (!skip_event) {
897 			struct drm_pending_vblank_event *event;
898 
899 			spin_lock_irqsave(&dev->event_lock, flags);
900 
901 			event = tilcdc_crtc->event;
902 			tilcdc_crtc->event = NULL;
903 			if (event)
904 				drm_crtc_send_vblank_event(crtc, event);
905 
906 			spin_unlock_irqrestore(&dev->event_lock, flags);
907 		}
908 
909 		if (tilcdc_crtc->frame_intact)
910 			tilcdc_crtc->sync_lost_count = 0;
911 		else
912 			tilcdc_crtc->frame_intact = true;
913 	}
914 
915 	if (stat & LCDC_FIFO_UNDERFLOW)
916 		dev_err_ratelimited(dev->dev, "%s(0x%08x): FIFO underflow",
917 				    __func__, stat);
918 
919 	if (stat & LCDC_PL_LOAD_DONE) {
920 		complete(&tilcdc_crtc->palette_loaded);
921 		if (priv->rev == 1)
922 			tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
923 				     LCDC_V1_PL_INT_ENA);
924 		else
925 			tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
926 				     LCDC_V2_PL_INT_ENA);
927 	}
928 
929 	if (stat & LCDC_SYNC_LOST) {
930 		dev_err_ratelimited(dev->dev, "%s(0x%08x): Sync lost",
931 				    __func__, stat);
932 		tilcdc_crtc->frame_intact = false;
933 		if (priv->rev == 1) {
934 			reg = tilcdc_read(dev, LCDC_RASTER_CTRL_REG);
935 			if (reg & LCDC_RASTER_ENABLE) {
936 				tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
937 					     LCDC_RASTER_ENABLE);
938 				tilcdc_set(dev, LCDC_RASTER_CTRL_REG,
939 					   LCDC_RASTER_ENABLE);
940 			}
941 		} else {
942 			if (tilcdc_crtc->sync_lost_count++ >
943 			    SYNC_LOST_COUNT_LIMIT) {
944 				dev_err(dev->dev,
945 					"%s(0x%08x): Sync lost flood detected, recovering",
946 					__func__, stat);
947 				queue_work(system_wq,
948 					   &tilcdc_crtc->recover_work);
949 				tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
950 					     LCDC_SYNC_LOST);
951 				tilcdc_crtc->sync_lost_count = 0;
952 			}
953 		}
954 	}
955 
956 	if (stat & LCDC_FRAME_DONE) {
957 		tilcdc_crtc->frame_done = true;
958 		wake_up(&tilcdc_crtc->frame_done_wq);
959 		/* rev 1 lcdc appears to hang if irq is not disbaled here */
960 		if (priv->rev == 1)
961 			tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
962 				     LCDC_V1_FRAME_DONE_INT_ENA);
963 	}
964 
965 	/* For revision 2 only */
966 	if (priv->rev == 2) {
967 		/* Indicate to LCDC that the interrupt service routine has
968 		 * completed, see 13.3.6.1.6 in AM335x TRM.
969 		 */
970 		tilcdc_write(dev, LCDC_END_OF_INT_IND_REG, 0);
971 	}
972 
973 	return IRQ_HANDLED;
974 }
975 
976 int tilcdc_crtc_create(struct drm_device *dev)
977 {
978 	struct tilcdc_drm_private *priv = dev->dev_private;
979 	struct tilcdc_crtc *tilcdc_crtc;
980 	struct drm_crtc *crtc;
981 	int ret;
982 
983 	tilcdc_crtc = devm_kzalloc(dev->dev, sizeof(*tilcdc_crtc), GFP_KERNEL);
984 	if (!tilcdc_crtc)
985 		return -ENOMEM;
986 
987 	init_completion(&tilcdc_crtc->palette_loaded);
988 	tilcdc_crtc->palette_base = dmam_alloc_coherent(dev->dev,
989 					TILCDC_PALETTE_SIZE,
990 					&tilcdc_crtc->palette_dma_handle,
991 					GFP_KERNEL | __GFP_ZERO);
992 	if (!tilcdc_crtc->palette_base)
993 		return -ENOMEM;
994 	*tilcdc_crtc->palette_base = TILCDC_PALETTE_FIRST_ENTRY;
995 
996 	crtc = &tilcdc_crtc->base;
997 
998 	ret = tilcdc_plane_init(dev, &tilcdc_crtc->primary);
999 	if (ret < 0)
1000 		goto fail;
1001 
1002 	mutex_init(&tilcdc_crtc->enable_lock);
1003 
1004 	init_waitqueue_head(&tilcdc_crtc->frame_done_wq);
1005 
1006 	spin_lock_init(&tilcdc_crtc->irq_lock);
1007 	INIT_WORK(&tilcdc_crtc->recover_work, tilcdc_crtc_recover_work);
1008 
1009 	ret = drm_crtc_init_with_planes(dev, crtc,
1010 					&tilcdc_crtc->primary,
1011 					NULL,
1012 					&tilcdc_crtc_funcs,
1013 					"tilcdc crtc");
1014 	if (ret < 0)
1015 		goto fail;
1016 
1017 	drm_crtc_helper_add(crtc, &tilcdc_crtc_helper_funcs);
1018 
1019 	if (priv->is_componentized) {
1020 		crtc->port = of_graph_get_port_by_id(dev->dev->of_node, 0);
1021 		if (!crtc->port) { /* This should never happen */
1022 			dev_err(dev->dev, "Port node not found in %pOF\n",
1023 				dev->dev->of_node);
1024 			ret = -EINVAL;
1025 			goto fail;
1026 		}
1027 	}
1028 
1029 	priv->crtc = crtc;
1030 	return 0;
1031 
1032 fail:
1033 	tilcdc_crtc_destroy(crtc);
1034 	return ret;
1035 }
1036