xref: /linux/drivers/gpu/drm/tilcdc/tilcdc_crtc.c (revision 2c6f1b1fa78acd5f3bd80e3519b6b23907ea9c2f)
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_dma_helper.h>
16 #include <drm/drm_fourcc.h>
17 #include <drm/drm_framebuffer.h>
18 #include <drm/drm_gem_dma_helper.h>
19 #include <drm/drm_managed.h>
20 #include <drm/drm_modeset_helper_vtables.h>
21 #include <drm/drm_print.h>
22 #include <drm/drm_vblank.h>
23 
24 #include "tilcdc_drv.h"
25 #include "tilcdc_regs.h"
26 
27 #define TILCDC_VBLANK_SAFETY_THRESHOLD_US	1000
28 #define TILCDC_PALETTE_SIZE			32
29 #define TILCDC_PALETTE_FIRST_ENTRY		0x4000
30 
31 struct tilcdc_crtc {
32 	struct drm_crtc base;
33 
34 	struct tilcdc_plane *primary;
35 	struct drm_pending_vblank_event *event;
36 	struct mutex enable_lock;
37 	bool enabled;
38 	bool shutdown;
39 	wait_queue_head_t frame_done_wq;
40 	bool frame_done;
41 	spinlock_t irq_lock;
42 
43 	unsigned int lcd_fck_rate;
44 
45 	ktime_t last_vblank;
46 	unsigned int hvtotal_us;
47 
48 	struct drm_framebuffer *next_fb;
49 
50 	int sync_lost_count;
51 	bool frame_intact;
52 	struct work_struct recover_work;
53 
54 	dma_addr_t palette_dma_handle;
55 	u16 *palette_base;
56 	struct completion palette_loaded;
57 };
58 #define to_tilcdc_crtc(x) container_of(x, struct tilcdc_crtc, base)
59 
60 static void set_scanout(struct drm_crtc *crtc, struct drm_framebuffer *fb)
61 {
62 	struct drm_device *dev = crtc->dev;
63 	struct tilcdc_drm_private *priv = ddev_to_tilcdc_priv(dev);
64 	struct drm_gem_dma_object *gem;
65 	dma_addr_t start, end;
66 	u64 dma_base_and_ceiling;
67 
68 	gem = drm_fb_dma_get_gem_obj(fb, 0);
69 
70 	start = gem->dma_addr + fb->offsets[0] +
71 		crtc->y * fb->pitches[0] +
72 		crtc->x * fb->format->cpp[0];
73 
74 	end = start + (crtc->mode.vdisplay * fb->pitches[0]);
75 
76 	/* Write LCDC_DMA_FB_BASE_ADDR_0_REG and LCDC_DMA_FB_CEILING_ADDR_0_REG
77 	 * with a single insruction, if available. This should make it more
78 	 * unlikely that LCDC would fetch the DMA addresses in the middle of
79 	 * an update.
80 	 */
81 	if (priv->rev == 1)
82 		end -= 1;
83 
84 	dma_base_and_ceiling = (u64)end << 32 | start;
85 	tilcdc_write64(dev, LCDC_DMA_FB_BASE_ADDR_0_REG, dma_base_and_ceiling);
86 }
87 
88 /*
89  * The driver currently only supports only true color formats. For
90  * true color the palette block is bypassed, but a 32 byte palette
91  * should still be loaded. The first 16-bit entry must be 0x4000 while
92  * all other entries must be zeroed.
93  */
94 static void tilcdc_crtc_load_palette(struct drm_crtc *crtc)
95 {
96 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
97 	struct drm_device *dev = crtc->dev;
98 	struct tilcdc_drm_private *priv = ddev_to_tilcdc_priv(dev);
99 	int ret;
100 
101 	reinit_completion(&tilcdc_crtc->palette_loaded);
102 
103 	/* Tell the LCDC where the palette is located. */
104 	tilcdc_write(dev, LCDC_DMA_FB_BASE_ADDR_0_REG,
105 		     tilcdc_crtc->palette_dma_handle);
106 	tilcdc_write(dev, LCDC_DMA_FB_CEILING_ADDR_0_REG,
107 		     (u32) tilcdc_crtc->palette_dma_handle +
108 		     TILCDC_PALETTE_SIZE - 1);
109 
110 	/* Set dma load mode for palette loading only. */
111 	tilcdc_write_mask(dev, LCDC_RASTER_CTRL_REG,
112 			  LCDC_PALETTE_LOAD_MODE(PALETTE_ONLY),
113 			  LCDC_PALETTE_LOAD_MODE_MASK);
114 
115 	/* Enable DMA Palette Loaded Interrupt */
116 	if (priv->rev == 1)
117 		tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_V1_PL_INT_ENA);
118 	else
119 		tilcdc_write(dev, LCDC_INT_ENABLE_SET_REG, LCDC_V2_PL_INT_ENA);
120 
121 	/* Enable LCDC DMA and wait for palette to be loaded. */
122 	tilcdc_clear_irqstatus(dev, 0xffffffff);
123 	tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
124 
125 	ret = wait_for_completion_timeout(&tilcdc_crtc->palette_loaded,
126 					  msecs_to_jiffies(50));
127 	if (ret == 0)
128 		drm_err(dev, "%s: Palette loading timeout", __func__);
129 
130 	/* Disable LCDC DMA and DMA Palette Loaded Interrupt. */
131 	tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
132 	if (priv->rev == 1)
133 		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_V1_PL_INT_ENA);
134 	else
135 		tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG, LCDC_V2_PL_INT_ENA);
136 }
137 
138 static void tilcdc_crtc_enable_irqs(struct drm_device *dev)
139 {
140 	struct tilcdc_drm_private *priv = ddev_to_tilcdc_priv(dev);
141 
142 	tilcdc_clear_irqstatus(dev, 0xffffffff);
143 
144 	if (priv->rev == 1) {
145 		tilcdc_set(dev, LCDC_RASTER_CTRL_REG,
146 			LCDC_V1_SYNC_LOST_INT_ENA | LCDC_V1_FRAME_DONE_INT_ENA |
147 			LCDC_V1_UNDERFLOW_INT_ENA);
148 	} else {
149 		tilcdc_write(dev, LCDC_INT_ENABLE_SET_REG,
150 			LCDC_V2_UNDERFLOW_INT_ENA |
151 			LCDC_FRAME_DONE | LCDC_SYNC_LOST);
152 	}
153 }
154 
155 static void tilcdc_crtc_disable_irqs(struct drm_device *dev)
156 {
157 	struct tilcdc_drm_private *priv = ddev_to_tilcdc_priv(dev);
158 
159 	/* disable irqs that we might have enabled: */
160 	if (priv->rev == 1) {
161 		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
162 			LCDC_V1_SYNC_LOST_INT_ENA | LCDC_V1_FRAME_DONE_INT_ENA |
163 			LCDC_V1_UNDERFLOW_INT_ENA | LCDC_V1_PL_INT_ENA);
164 		tilcdc_clear(dev, LCDC_DMA_CTRL_REG,
165 			LCDC_V1_END_OF_FRAME_INT_ENA);
166 	} else {
167 		tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
168 			LCDC_V2_UNDERFLOW_INT_ENA | LCDC_V2_PL_INT_ENA |
169 			LCDC_V2_END_OF_FRAME0_INT_ENA |
170 			LCDC_FRAME_DONE | LCDC_SYNC_LOST);
171 	}
172 }
173 
174 static void reset(struct drm_crtc *crtc)
175 {
176 	struct drm_device *dev = crtc->dev;
177 	struct tilcdc_drm_private *priv = ddev_to_tilcdc_priv(dev);
178 
179 	if (priv->rev != 2)
180 		return;
181 
182 	tilcdc_set(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
183 	usleep_range(250, 1000);
184 	tilcdc_clear(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
185 }
186 
187 /*
188  * Calculate the percentage difference between the requested pixel clock rate
189  * and the effective rate resulting from calculating the clock divider value.
190  */
191 static unsigned int tilcdc_pclk_diff(unsigned long rate,
192 				     unsigned long real_rate)
193 {
194 	int r = rate / 100, rr = real_rate / 100;
195 
196 	return (unsigned int)(abs(((rr - r) * 100) / r));
197 }
198 
199 static void tilcdc_crtc_set_clk(struct drm_crtc *crtc)
200 {
201 	struct drm_device *dev = crtc->dev;
202 	struct tilcdc_drm_private *priv = ddev_to_tilcdc_priv(dev);
203 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
204 	unsigned long clk_rate, real_pclk_rate, pclk_rate;
205 	unsigned int clkdiv;
206 	int ret;
207 
208 	clkdiv = 2; /* first try using a standard divider of 2 */
209 
210 	/* mode.clock is in KHz, set_rate wants parameter in Hz */
211 	pclk_rate = crtc->mode.clock * 1000;
212 
213 	ret = clk_set_rate(priv->clk, pclk_rate * clkdiv);
214 	clk_rate = clk_get_rate(priv->clk);
215 	real_pclk_rate = clk_rate / clkdiv;
216 	if (ret < 0 || tilcdc_pclk_diff(pclk_rate, real_pclk_rate) > 5) {
217 		/*
218 		 * If we fail to set the clock rate (some architectures don't
219 		 * use the common clock framework yet and may not implement
220 		 * all the clk API calls for every clock), try the next best
221 		 * thing: adjusting the clock divider, unless clk_get_rate()
222 		 * failed as well.
223 		 */
224 		if (!clk_rate) {
225 			/* Nothing more we can do. Just bail out. */
226 			drm_err(dev,
227 				"failed to set the pixel clock - unable to read current lcdc clock rate\n");
228 			return;
229 		}
230 
231 		clkdiv = DIV_ROUND_CLOSEST(clk_rate, pclk_rate);
232 
233 		/*
234 		 * Emit a warning if the real clock rate resulting from the
235 		 * calculated divider differs much from the requested rate.
236 		 *
237 		 * 5% is an arbitrary value - LCDs are usually quite tolerant
238 		 * about pixel clock rates.
239 		 */
240 		real_pclk_rate = clk_rate / clkdiv;
241 
242 		if (tilcdc_pclk_diff(pclk_rate, real_pclk_rate) > 5) {
243 			drm_warn(dev,
244 				 "effective pixel clock rate (%luHz) differs from the requested rate (%luHz)\n",
245 				 real_pclk_rate, pclk_rate);
246 		}
247 	}
248 
249 	tilcdc_crtc->lcd_fck_rate = clk_rate;
250 
251 	DBG("lcd_clk=%u, mode clock=%d, div=%u",
252 	    tilcdc_crtc->lcd_fck_rate, crtc->mode.clock, clkdiv);
253 
254 	/* Configure the LCD clock divisor. */
255 	tilcdc_write(dev, LCDC_CTRL_REG, LCDC_CLK_DIVISOR(clkdiv) |
256 		     LCDC_RASTER_MODE);
257 
258 	if (priv->rev == 2)
259 		tilcdc_set(dev, LCDC_CLK_ENABLE_REG,
260 				LCDC_V2_DMA_CLK_EN | LCDC_V2_LIDD_CLK_EN |
261 				LCDC_V2_CORE_CLK_EN);
262 }
263 
264 static uint tilcdc_mode_hvtotal(const struct drm_display_mode *mode)
265 {
266 	return (uint) div_u64(1000llu * mode->htotal * mode->vtotal,
267 			      mode->clock);
268 }
269 
270 static void tilcdc_crtc_set_mode(struct drm_crtc *crtc)
271 {
272 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
273 	struct drm_device *dev = crtc->dev;
274 	struct tilcdc_drm_private *priv = ddev_to_tilcdc_priv(dev);
275 	uint32_t reg, hbp, hfp, hsw, vbp, vfp, vsw;
276 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
277 	struct drm_framebuffer *fb = crtc->primary->state->fb;
278 
279 	if (WARN_ON(!fb))
280 		return;
281 
282 	/* Configure the Burst Size and fifo threshold of DMA: */
283 	reg = tilcdc_read(dev, LCDC_DMA_CTRL_REG) & ~0x00000770;
284 	/* Use 16 bit DMA burst size by default */
285 	reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_16);
286 
287 	if (priv->fifo_th) {
288 		int fifo_th_val = ilog2(priv->fifo_th) - 3;
289 
290 		reg |= (fifo_th_val << 8);
291 	}
292 	tilcdc_write(dev, LCDC_DMA_CTRL_REG, reg);
293 
294 	/* Configure timings: */
295 	hbp = mode->htotal - mode->hsync_end;
296 	hfp = mode->hsync_start - mode->hdisplay;
297 	hsw = mode->hsync_end - mode->hsync_start;
298 	vbp = mode->vtotal - mode->vsync_end;
299 	vfp = mode->vsync_start - mode->vdisplay;
300 	vsw = mode->vsync_end - mode->vsync_start;
301 
302 	DBG("%dx%d, hbp=%u, hfp=%u, hsw=%u, vbp=%u, vfp=%u, vsw=%u",
303 	    mode->hdisplay, mode->vdisplay, hbp, hfp, hsw, vbp, vfp, vsw);
304 
305 	/* Set AC Bias Period and Number of Transitions per Interrupt: */
306 	reg = tilcdc_read(dev, LCDC_RASTER_TIMING_2_REG) & ~0x000fff00;
307 	/* Use 255 AC Bias Pin Frequency by default */
308 	reg |= LCDC_AC_BIAS_FREQUENCY(255);
309 
310 	/*
311 	 * subtract one from hfp, hbp, hsw because the hardware uses
312 	 * a value of 0 as 1
313 	 */
314 	if (priv->rev == 2) {
315 		/* clear bits we're going to set */
316 		reg &= ~0x78000033;
317 		reg |= ((hfp-1) & 0x300) >> 8;
318 		reg |= ((hbp-1) & 0x300) >> 4;
319 		reg |= ((hsw-1) & 0x3c0) << 21;
320 	}
321 	tilcdc_write(dev, LCDC_RASTER_TIMING_2_REG, reg);
322 
323 	reg = (((mode->hdisplay >> 4) - 1) << 4) |
324 		(((hbp-1) & 0xff) << 24) |
325 		(((hfp-1) & 0xff) << 16) |
326 		(((hsw-1) & 0x3f) << 10);
327 	if (priv->rev == 2)
328 		reg |= (((mode->hdisplay >> 4) - 1) & 0x40) >> 3;
329 	tilcdc_write(dev, LCDC_RASTER_TIMING_0_REG, reg);
330 
331 	reg = ((mode->vdisplay - 1) & 0x3ff) |
332 		((vbp & 0xff) << 24) |
333 		((vfp & 0xff) << 16) |
334 		(((vsw-1) & 0x3f) << 10);
335 	tilcdc_write(dev, LCDC_RASTER_TIMING_1_REG, reg);
336 
337 	/*
338 	 * be sure to set Bit 10 for the V2 LCDC controller,
339 	 * otherwise limited to 1024 pixels width, stopping
340 	 * 1920x1080 being supported.
341 	 */
342 	if (priv->rev == 2) {
343 		if ((mode->vdisplay - 1) & 0x400) {
344 			tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG,
345 				LCDC_LPP_B10);
346 		} else {
347 			tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG,
348 				LCDC_LPP_B10);
349 		}
350 	}
351 
352 	/* Configure display type: */
353 	reg = tilcdc_read(dev, LCDC_RASTER_CTRL_REG) &
354 		~(LCDC_TFT_MODE | LCDC_MONO_8BIT_MODE | LCDC_MONOCHROME_MODE |
355 		  LCDC_V2_TFT_24BPP_MODE | LCDC_V2_TFT_24BPP_UNPACK |
356 		  0x000ff000 /* Palette Loading Delay bits */);
357 	reg |= LCDC_TFT_MODE; /* no monochrome/passive support */
358 	if (priv->rev == 2) {
359 		switch (fb->format->format) {
360 		case DRM_FORMAT_BGR565:
361 		case DRM_FORMAT_RGB565:
362 			break;
363 		case DRM_FORMAT_XBGR8888:
364 		case DRM_FORMAT_XRGB8888:
365 			reg |= LCDC_V2_TFT_24BPP_UNPACK;
366 			fallthrough;
367 		case DRM_FORMAT_BGR888:
368 		case DRM_FORMAT_RGB888:
369 			reg |= LCDC_V2_TFT_24BPP_MODE;
370 			break;
371 		default:
372 			drm_err(dev, "invalid pixel format\n");
373 			return;
374 		}
375 	}
376 	/* Use 128 FIFO DMA Request Delay by default */
377 	reg |= 128 << 12;
378 	tilcdc_write(dev, LCDC_RASTER_CTRL_REG, reg);
379 
380 	if (mode->flags == DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
381 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_PIXEL_CLOCK);
382 	else
383 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_PIXEL_CLOCK);
384 
385 	tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_CTRL);
386 	if (mode->flags == DRM_BUS_FLAG_SYNC_DRIVE_NEGEDGE)
387 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);
388 	else
389 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);
390 
391 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
392 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC);
393 	else
394 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC);
395 
396 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
397 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_VSYNC);
398 	else
399 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_VSYNC);
400 
401 	tilcdc_crtc_set_clk(crtc);
402 
403 	tilcdc_crtc_load_palette(crtc);
404 
405 	set_scanout(crtc, fb);
406 
407 	drm_mode_copy(&crtc->hwmode, &crtc->state->adjusted_mode);
408 
409 	tilcdc_crtc->hvtotal_us =
410 		tilcdc_mode_hvtotal(&crtc->hwmode);
411 }
412 
413 static void tilcdc_crtc_enable(struct drm_crtc *crtc)
414 {
415 	struct drm_device *dev = crtc->dev;
416 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
417 	unsigned long flags;
418 
419 	mutex_lock(&tilcdc_crtc->enable_lock);
420 	if (tilcdc_crtc->enabled || tilcdc_crtc->shutdown) {
421 		mutex_unlock(&tilcdc_crtc->enable_lock);
422 		return;
423 	}
424 
425 	pm_runtime_get_sync(dev->dev);
426 
427 	reset(crtc);
428 
429 	tilcdc_crtc_set_mode(crtc);
430 
431 	tilcdc_crtc_enable_irqs(dev);
432 
433 	tilcdc_clear(dev, LCDC_DMA_CTRL_REG, LCDC_DUAL_FRAME_BUFFER_ENABLE);
434 	tilcdc_write_mask(dev, LCDC_RASTER_CTRL_REG,
435 			  LCDC_PALETTE_LOAD_MODE(DATA_ONLY),
436 			  LCDC_PALETTE_LOAD_MODE_MASK);
437 
438 	/* There is no real chance for a race here as the time stamp
439 	 * is taken before the raster DMA is started. The spin-lock is
440 	 * taken to have a memory barrier after taking the time-stamp
441 	 * and to avoid a context switch between taking the stamp and
442 	 * enabling the raster.
443 	 */
444 	spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
445 	tilcdc_crtc->last_vblank = ktime_get();
446 	tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
447 	spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
448 
449 	drm_crtc_vblank_on(crtc);
450 
451 	tilcdc_crtc->enabled = true;
452 	mutex_unlock(&tilcdc_crtc->enable_lock);
453 }
454 
455 static void tilcdc_crtc_atomic_enable(struct drm_crtc *crtc,
456 				      struct drm_atomic_state *state)
457 {
458 	tilcdc_crtc_enable(crtc);
459 }
460 
461 static void tilcdc_crtc_off(struct drm_crtc *crtc, bool shutdown)
462 {
463 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
464 	struct drm_device *dev = crtc->dev;
465 	int ret;
466 
467 	mutex_lock(&tilcdc_crtc->enable_lock);
468 	if (shutdown)
469 		tilcdc_crtc->shutdown = true;
470 	if (!tilcdc_crtc->enabled) {
471 		mutex_unlock(&tilcdc_crtc->enable_lock);
472 		return;
473 	}
474 	tilcdc_crtc->frame_done = false;
475 	tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
476 
477 	/*
478 	 * Wait for framedone irq which will still come before putting
479 	 * things to sleep..
480 	 */
481 	ret = wait_event_timeout(tilcdc_crtc->frame_done_wq,
482 				 tilcdc_crtc->frame_done,
483 				 msecs_to_jiffies(500));
484 	if (ret == 0)
485 		drm_err(dev, "%s: timeout waiting for framedone\n",
486 			__func__);
487 
488 	drm_crtc_vblank_off(crtc);
489 
490 	spin_lock_irq(&crtc->dev->event_lock);
491 
492 	if (crtc->state->event) {
493 		drm_crtc_send_vblank_event(crtc, crtc->state->event);
494 		crtc->state->event = NULL;
495 	}
496 
497 	spin_unlock_irq(&crtc->dev->event_lock);
498 
499 	tilcdc_crtc_disable_irqs(dev);
500 
501 	pm_runtime_put_sync(dev->dev);
502 
503 	tilcdc_crtc->enabled = false;
504 	mutex_unlock(&tilcdc_crtc->enable_lock);
505 }
506 
507 static void tilcdc_crtc_disable(struct drm_crtc *crtc)
508 {
509 	tilcdc_crtc_off(crtc, false);
510 }
511 
512 static void tilcdc_crtc_atomic_disable(struct drm_crtc *crtc,
513 				       struct drm_atomic_state *state)
514 {
515 	tilcdc_crtc_disable(crtc);
516 }
517 
518 static void tilcdc_crtc_atomic_flush(struct drm_crtc *crtc,
519 				     struct drm_atomic_state *state)
520 {
521 	if (!crtc->state->event)
522 		return;
523 
524 	spin_lock_irq(&crtc->dev->event_lock);
525 	drm_crtc_send_vblank_event(crtc, crtc->state->event);
526 	crtc->state->event = NULL;
527 	spin_unlock_irq(&crtc->dev->event_lock);
528 }
529 
530 void tilcdc_crtc_shutdown(struct drm_crtc *crtc)
531 {
532 	tilcdc_crtc_off(crtc, true);
533 }
534 
535 static bool tilcdc_crtc_is_on(struct drm_crtc *crtc)
536 {
537 	return crtc->state && crtc->state->enable && crtc->state->active;
538 }
539 
540 static void tilcdc_crtc_recover_work(struct work_struct *work)
541 {
542 	struct tilcdc_crtc *tilcdc_crtc =
543 		container_of(work, struct tilcdc_crtc, recover_work);
544 	struct drm_crtc *crtc = &tilcdc_crtc->base;
545 
546 	drm_info(crtc->dev, "%s: Reset CRTC", __func__);
547 
548 	drm_modeset_lock(&crtc->mutex, NULL);
549 
550 	if (!tilcdc_crtc_is_on(crtc))
551 		goto out;
552 
553 	tilcdc_crtc_disable(crtc);
554 	tilcdc_crtc_enable(crtc);
555 out:
556 	drm_modeset_unlock(&crtc->mutex);
557 }
558 
559 static void tilcdc_crtc_destroy(struct drm_device *dev, void *data)
560 {
561 	struct tilcdc_drm_private *priv = (struct tilcdc_drm_private *)data;
562 
563 	tilcdc_crtc_shutdown(priv->crtc);
564 
565 	flush_workqueue(priv->wq);
566 
567 	of_node_put(priv->crtc->port);
568 }
569 
570 int tilcdc_crtc_update_fb(struct drm_crtc *crtc,
571 		struct drm_framebuffer *fb,
572 		struct drm_pending_vblank_event *event)
573 {
574 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
575 	struct drm_device *dev = crtc->dev;
576 
577 	if (tilcdc_crtc->event) {
578 		drm_err(dev, "already pending page flip!\n");
579 		return -EBUSY;
580 	}
581 
582 	tilcdc_crtc->event = event;
583 
584 	mutex_lock(&tilcdc_crtc->enable_lock);
585 
586 	if (tilcdc_crtc->enabled) {
587 		unsigned long flags;
588 		ktime_t next_vblank;
589 		s64 tdiff;
590 
591 		spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
592 
593 		next_vblank = ktime_add_us(tilcdc_crtc->last_vblank,
594 					   tilcdc_crtc->hvtotal_us);
595 		tdiff = ktime_to_us(ktime_sub(next_vblank, ktime_get()));
596 
597 		if (tdiff < TILCDC_VBLANK_SAFETY_THRESHOLD_US)
598 			tilcdc_crtc->next_fb = fb;
599 		else
600 			set_scanout(crtc, fb);
601 
602 		spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
603 	}
604 
605 	mutex_unlock(&tilcdc_crtc->enable_lock);
606 
607 	return 0;
608 }
609 
610 static bool tilcdc_crtc_mode_fixup(struct drm_crtc *crtc,
611 		const struct drm_display_mode *mode,
612 		struct drm_display_mode *adjusted_mode)
613 {
614 	/*
615 	 * tilcdc does not generate VESA-compliant sync but aligns
616 	 * VS on the second edge of HS instead of first edge.
617 	 * We use adjusted_mode, to fixup sync by aligning both rising
618 	 * edges and add HSKEW offset to fix the sync.
619 	 */
620 	adjusted_mode->hskew = mode->hsync_end - mode->hsync_start;
621 	adjusted_mode->flags |= DRM_MODE_FLAG_HSKEW;
622 
623 	if (mode->flags & DRM_MODE_FLAG_NHSYNC) {
624 		adjusted_mode->flags |= DRM_MODE_FLAG_PHSYNC;
625 		adjusted_mode->flags &= ~DRM_MODE_FLAG_NHSYNC;
626 	} else {
627 		adjusted_mode->flags |= DRM_MODE_FLAG_NHSYNC;
628 		adjusted_mode->flags &= ~DRM_MODE_FLAG_PHSYNC;
629 	}
630 
631 	return true;
632 }
633 
634 static int tilcdc_crtc_atomic_check(struct drm_crtc *crtc,
635 				    struct drm_atomic_state *state)
636 {
637 	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
638 									  crtc);
639 	/* If we are not active we don't care */
640 	if (!crtc_state->active)
641 		return 0;
642 
643 	return drm_atomic_helper_check_crtc_primary_plane(crtc_state);
644 }
645 
646 static int tilcdc_crtc_enable_vblank(struct drm_crtc *crtc)
647 {
648 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
649 	struct drm_device *dev = crtc->dev;
650 	struct tilcdc_drm_private *priv = ddev_to_tilcdc_priv(dev);
651 	unsigned long flags;
652 
653 	spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
654 
655 	tilcdc_clear_irqstatus(dev, LCDC_END_OF_FRAME0);
656 
657 	if (priv->rev == 1)
658 		tilcdc_set(dev, LCDC_DMA_CTRL_REG,
659 			   LCDC_V1_END_OF_FRAME_INT_ENA);
660 	else
661 		tilcdc_set(dev, LCDC_INT_ENABLE_SET_REG,
662 			   LCDC_V2_END_OF_FRAME0_INT_ENA);
663 
664 	spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
665 
666 	return 0;
667 }
668 
669 static void tilcdc_crtc_disable_vblank(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 = ddev_to_tilcdc_priv(dev);
674 	unsigned long flags;
675 
676 	spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
677 
678 	if (priv->rev == 1)
679 		tilcdc_clear(dev, LCDC_DMA_CTRL_REG,
680 			     LCDC_V1_END_OF_FRAME_INT_ENA);
681 	else
682 		tilcdc_clear(dev, LCDC_INT_ENABLE_SET_REG,
683 			     LCDC_V2_END_OF_FRAME0_INT_ENA);
684 
685 	spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
686 }
687 
688 static void tilcdc_crtc_reset(struct drm_crtc *crtc)
689 {
690 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
691 	struct drm_device *dev = crtc->dev;
692 	int ret;
693 
694 	drm_atomic_helper_crtc_reset(crtc);
695 
696 	/* Turn the raster off if it for some reason is on. */
697 	pm_runtime_get_sync(dev->dev);
698 	if (tilcdc_read(dev, LCDC_RASTER_CTRL_REG) & LCDC_RASTER_ENABLE) {
699 		/* Enable DMA Frame Done Interrupt */
700 		tilcdc_write(dev, LCDC_INT_ENABLE_SET_REG, LCDC_FRAME_DONE);
701 		tilcdc_clear_irqstatus(dev, 0xffffffff);
702 
703 		tilcdc_crtc->frame_done = false;
704 		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
705 
706 		ret = wait_event_timeout(tilcdc_crtc->frame_done_wq,
707 					 tilcdc_crtc->frame_done,
708 					 msecs_to_jiffies(500));
709 		if (ret == 0)
710 			drm_err(dev, "%s: timeout waiting for framedone\n",
711 				__func__);
712 	}
713 	pm_runtime_put_sync(dev->dev);
714 }
715 
716 static const struct drm_crtc_funcs tilcdc_crtc_funcs = {
717 	.set_config     = drm_atomic_helper_set_config,
718 	.page_flip      = drm_atomic_helper_page_flip,
719 	.reset		= tilcdc_crtc_reset,
720 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
721 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
722 	.enable_vblank	= tilcdc_crtc_enable_vblank,
723 	.disable_vblank	= tilcdc_crtc_disable_vblank,
724 };
725 
726 static enum drm_mode_status
727 tilcdc_crtc_mode_valid(struct drm_crtc *crtc,
728 		       const struct drm_display_mode *mode)
729 {
730 	struct tilcdc_drm_private *priv = ddev_to_tilcdc_priv(crtc->dev);
731 	unsigned int bandwidth;
732 	uint32_t hbp, hfp, hsw, vbp, vfp, vsw;
733 
734 	/*
735 	 * check to see if the width is within the range that
736 	 * the LCD Controller physically supports
737 	 */
738 	if (mode->hdisplay > priv->max_width)
739 		return MODE_VIRTUAL_X;
740 
741 	/* width must be multiple of 16 */
742 	if (mode->hdisplay & 0xf)
743 		return MODE_VIRTUAL_X;
744 
745 	if (mode->vdisplay > 2048)
746 		return MODE_VIRTUAL_Y;
747 
748 	DBG("Processing mode %dx%d@%d with pixel clock %d",
749 		mode->hdisplay, mode->vdisplay,
750 		drm_mode_vrefresh(mode), mode->clock);
751 
752 	hbp = mode->htotal - mode->hsync_end;
753 	hfp = mode->hsync_start - mode->hdisplay;
754 	hsw = mode->hsync_end - mode->hsync_start;
755 	vbp = mode->vtotal - mode->vsync_end;
756 	vfp = mode->vsync_start - mode->vdisplay;
757 	vsw = mode->vsync_end - mode->vsync_start;
758 
759 	if ((hbp-1) & ~0x3ff) {
760 		DBG("Pruning mode: Horizontal Back Porch out of range");
761 		return MODE_HBLANK_WIDE;
762 	}
763 
764 	if ((hfp-1) & ~0x3ff) {
765 		DBG("Pruning mode: Horizontal Front Porch out of range");
766 		return MODE_HBLANK_WIDE;
767 	}
768 
769 	if ((hsw-1) & ~0x3ff) {
770 		DBG("Pruning mode: Horizontal Sync Width out of range");
771 		return MODE_HSYNC_WIDE;
772 	}
773 
774 	if (vbp & ~0xff) {
775 		DBG("Pruning mode: Vertical Back Porch out of range");
776 		return MODE_VBLANK_WIDE;
777 	}
778 
779 	if (vfp & ~0xff) {
780 		DBG("Pruning mode: Vertical Front Porch out of range");
781 		return MODE_VBLANK_WIDE;
782 	}
783 
784 	if ((vsw-1) & ~0x3f) {
785 		DBG("Pruning mode: Vertical Sync Width out of range");
786 		return MODE_VSYNC_WIDE;
787 	}
788 
789 	/*
790 	 * some devices have a maximum allowed pixel clock
791 	 * configured from the DT
792 	 */
793 	if (mode->clock > priv->max_pixelclock) {
794 		DBG("Pruning mode: pixel clock too high");
795 		return MODE_CLOCK_HIGH;
796 	}
797 
798 	/*
799 	 * some devices further limit the max horizontal resolution
800 	 * configured from the DT
801 	 */
802 	if (mode->hdisplay > priv->max_width)
803 		return MODE_BAD_WIDTH;
804 
805 	/* filter out modes that would require too much memory bandwidth: */
806 	bandwidth = mode->hdisplay * mode->vdisplay *
807 		drm_mode_vrefresh(mode);
808 	if (bandwidth > priv->max_bandwidth) {
809 		DBG("Pruning mode: exceeds defined bandwidth limit");
810 		return MODE_BAD;
811 	}
812 
813 	return MODE_OK;
814 }
815 
816 static const struct drm_crtc_helper_funcs tilcdc_crtc_helper_funcs = {
817 	.mode_valid	= tilcdc_crtc_mode_valid,
818 	.mode_fixup	= tilcdc_crtc_mode_fixup,
819 	.atomic_check	= tilcdc_crtc_atomic_check,
820 	.atomic_enable	= tilcdc_crtc_atomic_enable,
821 	.atomic_disable	= tilcdc_crtc_atomic_disable,
822 	.atomic_flush	= tilcdc_crtc_atomic_flush,
823 };
824 
825 void tilcdc_crtc_update_clk(struct drm_crtc *crtc)
826 {
827 	struct drm_device *dev = crtc->dev;
828 	struct tilcdc_drm_private *priv = ddev_to_tilcdc_priv(dev);
829 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
830 
831 	drm_modeset_lock(&crtc->mutex, NULL);
832 	if (tilcdc_crtc->lcd_fck_rate != clk_get_rate(priv->clk)) {
833 		if (tilcdc_crtc_is_on(crtc)) {
834 			pm_runtime_get_sync(dev->dev);
835 			tilcdc_crtc_disable(crtc);
836 
837 			tilcdc_crtc_set_clk(crtc);
838 
839 			tilcdc_crtc_enable(crtc);
840 			pm_runtime_put_sync(dev->dev);
841 		}
842 	}
843 	drm_modeset_unlock(&crtc->mutex);
844 }
845 
846 #define SYNC_LOST_COUNT_LIMIT 50
847 
848 irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
849 {
850 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
851 	struct drm_device *dev = crtc->dev;
852 	struct tilcdc_drm_private *priv = ddev_to_tilcdc_priv(dev);
853 	uint32_t stat, reg;
854 
855 	stat = tilcdc_read_irqstatus(dev);
856 	tilcdc_clear_irqstatus(dev, stat);
857 
858 	if (stat & LCDC_END_OF_FRAME0) {
859 		bool skip_event = false;
860 		ktime_t now;
861 
862 		now = ktime_get();
863 
864 		spin_lock(&tilcdc_crtc->irq_lock);
865 
866 		tilcdc_crtc->last_vblank = now;
867 
868 		if (tilcdc_crtc->next_fb) {
869 			set_scanout(crtc, tilcdc_crtc->next_fb);
870 			tilcdc_crtc->next_fb = NULL;
871 			skip_event = true;
872 		}
873 
874 		spin_unlock(&tilcdc_crtc->irq_lock);
875 
876 		drm_crtc_handle_vblank(crtc);
877 
878 		if (!skip_event) {
879 			struct drm_pending_vblank_event *event;
880 
881 			spin_lock(&dev->event_lock);
882 
883 			event = tilcdc_crtc->event;
884 			tilcdc_crtc->event = NULL;
885 			if (event)
886 				drm_crtc_send_vblank_event(crtc, event);
887 
888 			spin_unlock(&dev->event_lock);
889 		}
890 
891 		if (tilcdc_crtc->frame_intact)
892 			tilcdc_crtc->sync_lost_count = 0;
893 		else
894 			tilcdc_crtc->frame_intact = true;
895 	}
896 
897 	if (stat & LCDC_FIFO_UNDERFLOW)
898 		drm_err_ratelimited(dev, "%s(0x%08x): FIFO underflow",
899 				    __func__, stat);
900 
901 	if (stat & LCDC_PL_LOAD_DONE) {
902 		complete(&tilcdc_crtc->palette_loaded);
903 		if (priv->rev == 1)
904 			tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
905 				     LCDC_V1_PL_INT_ENA);
906 		else
907 			tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
908 				     LCDC_V2_PL_INT_ENA);
909 	}
910 
911 	if (stat & LCDC_SYNC_LOST) {
912 		drm_err_ratelimited(dev, "%s(0x%08x): Sync lost",
913 				    __func__, stat);
914 		tilcdc_crtc->frame_intact = false;
915 		if (priv->rev == 1) {
916 			reg = tilcdc_read(dev, LCDC_RASTER_CTRL_REG);
917 			if (reg & LCDC_RASTER_ENABLE) {
918 				tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
919 					     LCDC_RASTER_ENABLE);
920 				tilcdc_set(dev, LCDC_RASTER_CTRL_REG,
921 					   LCDC_RASTER_ENABLE);
922 			}
923 		} else {
924 			if (tilcdc_crtc->sync_lost_count++ >
925 			    SYNC_LOST_COUNT_LIMIT) {
926 				drm_err(dev,
927 					"%s(0x%08x): Sync lost flood detected, recovering",
928 					__func__, stat);
929 				queue_work(system_wq,
930 					   &tilcdc_crtc->recover_work);
931 				tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
932 					     LCDC_SYNC_LOST);
933 				tilcdc_crtc->sync_lost_count = 0;
934 			}
935 		}
936 	}
937 
938 	if (stat & LCDC_FRAME_DONE) {
939 		tilcdc_crtc->frame_done = true;
940 		wake_up(&tilcdc_crtc->frame_done_wq);
941 		/* rev 1 lcdc appears to hang if irq is not disabled here */
942 		if (priv->rev == 1)
943 			tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
944 				     LCDC_V1_FRAME_DONE_INT_ENA);
945 	}
946 
947 	/* For revision 2 only */
948 	if (priv->rev == 2) {
949 		/* Indicate to LCDC that the interrupt service routine has
950 		 * completed, see 13.3.6.1.6 in AM335x TRM.
951 		 */
952 		tilcdc_write(dev, LCDC_END_OF_INT_IND_REG, 0);
953 	}
954 
955 	return IRQ_HANDLED;
956 }
957 
958 int tilcdc_crtc_create(struct drm_device *dev)
959 {
960 	struct tilcdc_drm_private *priv = ddev_to_tilcdc_priv(dev);
961 	struct tilcdc_crtc *tilcdc_crtc;
962 	struct tilcdc_plane *primary;
963 	struct drm_crtc *crtc;
964 	int ret;
965 
966 	primary = tilcdc_plane_init(dev);
967 	if (IS_ERR(primary)) {
968 		drm_err(dev, "Failed to initialize plane: %pe\n", primary);
969 		return PTR_ERR(primary);
970 	}
971 
972 	tilcdc_crtc = drmm_crtc_alloc_with_planes(dev, struct tilcdc_crtc, base,
973 						  &primary->base,
974 						  NULL,
975 						  &tilcdc_crtc_funcs,
976 						  "tilcdc crtc");
977 	if (IS_ERR(tilcdc_crtc)) {
978 		drm_err(dev, "Failed to init CRTC: %pe\n", tilcdc_crtc);
979 		return PTR_ERR(tilcdc_crtc);
980 	}
981 
982 	tilcdc_crtc->primary = primary;
983 	priv->crtc = &tilcdc_crtc->base;
984 	ret = drmm_add_action_or_reset(dev, tilcdc_crtc_destroy, priv);
985 	if (ret)
986 		return ret;
987 
988 	init_completion(&tilcdc_crtc->palette_loaded);
989 	tilcdc_crtc->palette_base = dmam_alloc_coherent(dev->dev,
990 					TILCDC_PALETTE_SIZE,
991 					&tilcdc_crtc->palette_dma_handle,
992 					GFP_KERNEL | __GFP_ZERO);
993 	if (!tilcdc_crtc->palette_base)
994 		return -ENOMEM;
995 	*tilcdc_crtc->palette_base = TILCDC_PALETTE_FIRST_ENTRY;
996 
997 	crtc = &tilcdc_crtc->base;
998 
999 	mutex_init(&tilcdc_crtc->enable_lock);
1000 
1001 	init_waitqueue_head(&tilcdc_crtc->frame_done_wq);
1002 
1003 	spin_lock_init(&tilcdc_crtc->irq_lock);
1004 	INIT_WORK(&tilcdc_crtc->recover_work, tilcdc_crtc_recover_work);
1005 
1006 	drm_crtc_helper_add(crtc, &tilcdc_crtc_helper_funcs);
1007 
1008 	return 0;
1009 }
1010