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_modeset_helper_vtables.h>
20 #include <drm/drm_print.h>
21 #include <drm/drm_vblank.h>
22 
23 #include "tilcdc_drv.h"
24 #include "tilcdc_regs.h"
25 
26 #define TILCDC_VBLANK_SAFETY_THRESHOLD_US	1000
27 #define TILCDC_PALETTE_SIZE			32
28 #define TILCDC_PALETTE_FIRST_ENTRY		0x4000
29 
30 struct tilcdc_crtc {
31 	struct drm_crtc base;
32 
33 	struct drm_plane primary;
34 	const struct tilcdc_panel_info *info;
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 	/* Only set if an external encoder is connected */
51 	bool simulate_vesa_sync;
52 
53 	int sync_lost_count;
54 	bool frame_intact;
55 	struct work_struct recover_work;
56 
57 	dma_addr_t palette_dma_handle;
58 	u16 *palette_base;
59 	struct completion palette_loaded;
60 };
61 #define to_tilcdc_crtc(x) container_of(x, struct tilcdc_crtc, base)
62 
set_scanout(struct drm_crtc * crtc,struct drm_framebuffer * fb)63 static void set_scanout(struct drm_crtc *crtc, struct drm_framebuffer *fb)
64 {
65 	struct drm_device *dev = crtc->dev;
66 	struct tilcdc_drm_private *priv = dev->dev_private;
67 	struct drm_gem_dma_object *gem;
68 	dma_addr_t start, end;
69 	u64 dma_base_and_ceiling;
70 
71 	gem = drm_fb_dma_get_gem_obj(fb, 0);
72 
73 	start = gem->dma_addr + fb->offsets[0] +
74 		crtc->y * fb->pitches[0] +
75 		crtc->x * fb->format->cpp[0];
76 
77 	end = start + (crtc->mode.vdisplay * fb->pitches[0]);
78 
79 	/* Write LCDC_DMA_FB_BASE_ADDR_0_REG and LCDC_DMA_FB_CEILING_ADDR_0_REG
80 	 * with a single insruction, if available. This should make it more
81 	 * unlikely that LCDC would fetch the DMA addresses in the middle of
82 	 * an update.
83 	 */
84 	if (priv->rev == 1)
85 		end -= 1;
86 
87 	dma_base_and_ceiling = (u64)end << 32 | start;
88 	tilcdc_write64(dev, LCDC_DMA_FB_BASE_ADDR_0_REG, dma_base_and_ceiling);
89 }
90 
91 /*
92  * The driver currently only supports only true color formats. For
93  * true color the palette block is bypassed, but a 32 byte palette
94  * should still be loaded. The first 16-bit entry must be 0x4000 while
95  * all other entries must be zeroed.
96  */
tilcdc_crtc_load_palette(struct drm_crtc * crtc)97 static void tilcdc_crtc_load_palette(struct drm_crtc *crtc)
98 {
99 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
100 	struct drm_device *dev = crtc->dev;
101 	struct tilcdc_drm_private *priv = dev->dev_private;
102 	int ret;
103 
104 	reinit_completion(&tilcdc_crtc->palette_loaded);
105 
106 	/* Tell the LCDC where the palette is located. */
107 	tilcdc_write(dev, LCDC_DMA_FB_BASE_ADDR_0_REG,
108 		     tilcdc_crtc->palette_dma_handle);
109 	tilcdc_write(dev, LCDC_DMA_FB_CEILING_ADDR_0_REG,
110 		     (u32) tilcdc_crtc->palette_dma_handle +
111 		     TILCDC_PALETTE_SIZE - 1);
112 
113 	/* Set dma load mode for palette loading only. */
114 	tilcdc_write_mask(dev, LCDC_RASTER_CTRL_REG,
115 			  LCDC_PALETTE_LOAD_MODE(PALETTE_ONLY),
116 			  LCDC_PALETTE_LOAD_MODE_MASK);
117 
118 	/* Enable DMA Palette Loaded Interrupt */
119 	if (priv->rev == 1)
120 		tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_V1_PL_INT_ENA);
121 	else
122 		tilcdc_write(dev, LCDC_INT_ENABLE_SET_REG, LCDC_V2_PL_INT_ENA);
123 
124 	/* Enable LCDC DMA and wait for palette to be loaded. */
125 	tilcdc_clear_irqstatus(dev, 0xffffffff);
126 	tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
127 
128 	ret = wait_for_completion_timeout(&tilcdc_crtc->palette_loaded,
129 					  msecs_to_jiffies(50));
130 	if (ret == 0)
131 		dev_err(dev->dev, "%s: Palette loading timeout", __func__);
132 
133 	/* Disable LCDC DMA and DMA Palette Loaded Interrupt. */
134 	tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
135 	if (priv->rev == 1)
136 		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_V1_PL_INT_ENA);
137 	else
138 		tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG, LCDC_V2_PL_INT_ENA);
139 }
140 
tilcdc_crtc_enable_irqs(struct drm_device * dev)141 static void tilcdc_crtc_enable_irqs(struct drm_device *dev)
142 {
143 	struct tilcdc_drm_private *priv = dev->dev_private;
144 
145 	tilcdc_clear_irqstatus(dev, 0xffffffff);
146 
147 	if (priv->rev == 1) {
148 		tilcdc_set(dev, LCDC_RASTER_CTRL_REG,
149 			LCDC_V1_SYNC_LOST_INT_ENA | LCDC_V1_FRAME_DONE_INT_ENA |
150 			LCDC_V1_UNDERFLOW_INT_ENA);
151 	} else {
152 		tilcdc_write(dev, LCDC_INT_ENABLE_SET_REG,
153 			LCDC_V2_UNDERFLOW_INT_ENA |
154 			LCDC_FRAME_DONE | LCDC_SYNC_LOST);
155 	}
156 }
157 
tilcdc_crtc_disable_irqs(struct drm_device * dev)158 static void tilcdc_crtc_disable_irqs(struct drm_device *dev)
159 {
160 	struct tilcdc_drm_private *priv = dev->dev_private;
161 
162 	/* disable irqs that we might have enabled: */
163 	if (priv->rev == 1) {
164 		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
165 			LCDC_V1_SYNC_LOST_INT_ENA | LCDC_V1_FRAME_DONE_INT_ENA |
166 			LCDC_V1_UNDERFLOW_INT_ENA | LCDC_V1_PL_INT_ENA);
167 		tilcdc_clear(dev, LCDC_DMA_CTRL_REG,
168 			LCDC_V1_END_OF_FRAME_INT_ENA);
169 	} else {
170 		tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
171 			LCDC_V2_UNDERFLOW_INT_ENA | LCDC_V2_PL_INT_ENA |
172 			LCDC_V2_END_OF_FRAME0_INT_ENA |
173 			LCDC_FRAME_DONE | LCDC_SYNC_LOST);
174 	}
175 }
176 
reset(struct drm_crtc * crtc)177 static void reset(struct drm_crtc *crtc)
178 {
179 	struct drm_device *dev = crtc->dev;
180 	struct tilcdc_drm_private *priv = dev->dev_private;
181 
182 	if (priv->rev != 2)
183 		return;
184 
185 	tilcdc_set(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
186 	usleep_range(250, 1000);
187 	tilcdc_clear(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
188 }
189 
190 /*
191  * Calculate the percentage difference between the requested pixel clock rate
192  * and the effective rate resulting from calculating the clock divider value.
193  */
tilcdc_pclk_diff(unsigned long rate,unsigned long real_rate)194 static unsigned int tilcdc_pclk_diff(unsigned long rate,
195 				     unsigned long real_rate)
196 {
197 	int r = rate / 100, rr = real_rate / 100;
198 
199 	return (unsigned int)(abs(((rr - r) * 100) / r));
200 }
201 
tilcdc_crtc_set_clk(struct drm_crtc * crtc)202 static void tilcdc_crtc_set_clk(struct drm_crtc *crtc)
203 {
204 	struct drm_device *dev = crtc->dev;
205 	struct tilcdc_drm_private *priv = dev->dev_private;
206 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
207 	unsigned long clk_rate, real_pclk_rate, pclk_rate;
208 	unsigned int clkdiv;
209 	int ret;
210 
211 	clkdiv = 2; /* first try using a standard divider of 2 */
212 
213 	/* mode.clock is in KHz, set_rate wants parameter in Hz */
214 	pclk_rate = crtc->mode.clock * 1000;
215 
216 	ret = clk_set_rate(priv->clk, pclk_rate * clkdiv);
217 	clk_rate = clk_get_rate(priv->clk);
218 	real_pclk_rate = clk_rate / clkdiv;
219 	if (ret < 0 || tilcdc_pclk_diff(pclk_rate, real_pclk_rate) > 5) {
220 		/*
221 		 * If we fail to set the clock rate (some architectures don't
222 		 * use the common clock framework yet and may not implement
223 		 * all the clk API calls for every clock), try the next best
224 		 * thing: adjusting the clock divider, unless clk_get_rate()
225 		 * failed as well.
226 		 */
227 		if (!clk_rate) {
228 			/* Nothing more we can do. Just bail out. */
229 			dev_err(dev->dev,
230 				"failed to set the pixel clock - unable to read current lcdc clock rate\n");
231 			return;
232 		}
233 
234 		clkdiv = DIV_ROUND_CLOSEST(clk_rate, pclk_rate);
235 
236 		/*
237 		 * Emit a warning if the real clock rate resulting from the
238 		 * calculated divider differs much from the requested rate.
239 		 *
240 		 * 5% is an arbitrary value - LCDs are usually quite tolerant
241 		 * about pixel clock rates.
242 		 */
243 		real_pclk_rate = clk_rate / clkdiv;
244 
245 		if (tilcdc_pclk_diff(pclk_rate, real_pclk_rate) > 5) {
246 			dev_warn(dev->dev,
247 				 "effective pixel clock rate (%luHz) differs from the requested rate (%luHz)\n",
248 				 real_pclk_rate, pclk_rate);
249 		}
250 	}
251 
252 	tilcdc_crtc->lcd_fck_rate = clk_rate;
253 
254 	DBG("lcd_clk=%u, mode clock=%d, div=%u",
255 	    tilcdc_crtc->lcd_fck_rate, crtc->mode.clock, clkdiv);
256 
257 	/* Configure the LCD clock divisor. */
258 	tilcdc_write(dev, LCDC_CTRL_REG, LCDC_CLK_DIVISOR(clkdiv) |
259 		     LCDC_RASTER_MODE);
260 
261 	if (priv->rev == 2)
262 		tilcdc_set(dev, LCDC_CLK_ENABLE_REG,
263 				LCDC_V2_DMA_CLK_EN | LCDC_V2_LIDD_CLK_EN |
264 				LCDC_V2_CORE_CLK_EN);
265 }
266 
tilcdc_mode_hvtotal(const struct drm_display_mode * mode)267 static uint tilcdc_mode_hvtotal(const struct drm_display_mode *mode)
268 {
269 	return (uint) div_u64(1000llu * mode->htotal * mode->vtotal,
270 			      mode->clock);
271 }
272 
tilcdc_crtc_set_mode(struct drm_crtc * crtc)273 static void tilcdc_crtc_set_mode(struct drm_crtc *crtc)
274 {
275 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
276 	struct drm_device *dev = crtc->dev;
277 	struct tilcdc_drm_private *priv = dev->dev_private;
278 	const struct tilcdc_panel_info *info = tilcdc_crtc->info;
279 	uint32_t reg, hbp, hfp, hsw, vbp, vfp, vsw;
280 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
281 	struct drm_framebuffer *fb = crtc->primary->state->fb;
282 
283 	if (WARN_ON(!info))
284 		return;
285 
286 	if (WARN_ON(!fb))
287 		return;
288 
289 	/* Configure the Burst Size and fifo threshold of DMA: */
290 	reg = tilcdc_read(dev, LCDC_DMA_CTRL_REG) & ~0x00000770;
291 	switch (info->dma_burst_sz) {
292 	case 1:
293 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_1);
294 		break;
295 	case 2:
296 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_2);
297 		break;
298 	case 4:
299 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_4);
300 		break;
301 	case 8:
302 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_8);
303 		break;
304 	case 16:
305 		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_16);
306 		break;
307 	default:
308 		dev_err(dev->dev, "invalid burst size\n");
309 		return;
310 	}
311 	reg |= (info->fifo_th << 8);
312 	tilcdc_write(dev, LCDC_DMA_CTRL_REG, reg);
313 
314 	/* Configure timings: */
315 	hbp = mode->htotal - mode->hsync_end;
316 	hfp = mode->hsync_start - mode->hdisplay;
317 	hsw = mode->hsync_end - mode->hsync_start;
318 	vbp = mode->vtotal - mode->vsync_end;
319 	vfp = mode->vsync_start - mode->vdisplay;
320 	vsw = mode->vsync_end - mode->vsync_start;
321 
322 	DBG("%dx%d, hbp=%u, hfp=%u, hsw=%u, vbp=%u, vfp=%u, vsw=%u",
323 	    mode->hdisplay, mode->vdisplay, hbp, hfp, hsw, vbp, vfp, vsw);
324 
325 	/* Set AC Bias Period and Number of Transitions per Interrupt: */
326 	reg = tilcdc_read(dev, LCDC_RASTER_TIMING_2_REG) & ~0x000fff00;
327 	reg |= LCDC_AC_BIAS_FREQUENCY(info->ac_bias) |
328 		LCDC_AC_BIAS_TRANSITIONS_PER_INT(info->ac_bias_intrpt);
329 
330 	/*
331 	 * subtract one from hfp, hbp, hsw because the hardware uses
332 	 * a value of 0 as 1
333 	 */
334 	if (priv->rev == 2) {
335 		/* clear bits we're going to set */
336 		reg &= ~0x78000033;
337 		reg |= ((hfp-1) & 0x300) >> 8;
338 		reg |= ((hbp-1) & 0x300) >> 4;
339 		reg |= ((hsw-1) & 0x3c0) << 21;
340 	}
341 	tilcdc_write(dev, LCDC_RASTER_TIMING_2_REG, reg);
342 
343 	reg = (((mode->hdisplay >> 4) - 1) << 4) |
344 		(((hbp-1) & 0xff) << 24) |
345 		(((hfp-1) & 0xff) << 16) |
346 		(((hsw-1) & 0x3f) << 10);
347 	if (priv->rev == 2)
348 		reg |= (((mode->hdisplay >> 4) - 1) & 0x40) >> 3;
349 	tilcdc_write(dev, LCDC_RASTER_TIMING_0_REG, reg);
350 
351 	reg = ((mode->vdisplay - 1) & 0x3ff) |
352 		((vbp & 0xff) << 24) |
353 		((vfp & 0xff) << 16) |
354 		(((vsw-1) & 0x3f) << 10);
355 	tilcdc_write(dev, LCDC_RASTER_TIMING_1_REG, reg);
356 
357 	/*
358 	 * be sure to set Bit 10 for the V2 LCDC controller,
359 	 * otherwise limited to 1024 pixels width, stopping
360 	 * 1920x1080 being supported.
361 	 */
362 	if (priv->rev == 2) {
363 		if ((mode->vdisplay - 1) & 0x400) {
364 			tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG,
365 				LCDC_LPP_B10);
366 		} else {
367 			tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG,
368 				LCDC_LPP_B10);
369 		}
370 	}
371 
372 	/* Configure display type: */
373 	reg = tilcdc_read(dev, LCDC_RASTER_CTRL_REG) &
374 		~(LCDC_TFT_MODE | LCDC_MONO_8BIT_MODE | LCDC_MONOCHROME_MODE |
375 		  LCDC_V2_TFT_24BPP_MODE | LCDC_V2_TFT_24BPP_UNPACK |
376 		  0x000ff000 /* Palette Loading Delay bits */);
377 	reg |= LCDC_TFT_MODE; /* no monochrome/passive support */
378 	if (info->tft_alt_mode)
379 		reg |= LCDC_TFT_ALT_ENABLE;
380 	if (priv->rev == 2) {
381 		switch (fb->format->format) {
382 		case DRM_FORMAT_BGR565:
383 		case DRM_FORMAT_RGB565:
384 			break;
385 		case DRM_FORMAT_XBGR8888:
386 		case DRM_FORMAT_XRGB8888:
387 			reg |= LCDC_V2_TFT_24BPP_UNPACK;
388 			fallthrough;
389 		case DRM_FORMAT_BGR888:
390 		case DRM_FORMAT_RGB888:
391 			reg |= LCDC_V2_TFT_24BPP_MODE;
392 			break;
393 		default:
394 			dev_err(dev->dev, "invalid pixel format\n");
395 			return;
396 		}
397 	}
398 	reg |= info->fdd << 12;
399 	tilcdc_write(dev, LCDC_RASTER_CTRL_REG, reg);
400 
401 	if (info->invert_pxl_clk)
402 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_PIXEL_CLOCK);
403 	else
404 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_PIXEL_CLOCK);
405 
406 	if (info->sync_ctrl)
407 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_CTRL);
408 	else
409 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_CTRL);
410 
411 	if (info->sync_edge)
412 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);
413 	else
414 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);
415 
416 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
417 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC);
418 	else
419 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC);
420 
421 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
422 		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_VSYNC);
423 	else
424 		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_VSYNC);
425 
426 	if (info->raster_order)
427 		tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ORDER);
428 	else
429 		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ORDER);
430 
431 	tilcdc_crtc_set_clk(crtc);
432 
433 	tilcdc_crtc_load_palette(crtc);
434 
435 	set_scanout(crtc, fb);
436 
437 	drm_mode_copy(&crtc->hwmode, &crtc->state->adjusted_mode);
438 
439 	tilcdc_crtc->hvtotal_us =
440 		tilcdc_mode_hvtotal(&crtc->hwmode);
441 }
442 
tilcdc_crtc_enable(struct drm_crtc * crtc)443 static void tilcdc_crtc_enable(struct drm_crtc *crtc)
444 {
445 	struct drm_device *dev = crtc->dev;
446 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
447 	unsigned long flags;
448 
449 	mutex_lock(&tilcdc_crtc->enable_lock);
450 	if (tilcdc_crtc->enabled || tilcdc_crtc->shutdown) {
451 		mutex_unlock(&tilcdc_crtc->enable_lock);
452 		return;
453 	}
454 
455 	pm_runtime_get_sync(dev->dev);
456 
457 	reset(crtc);
458 
459 	tilcdc_crtc_set_mode(crtc);
460 
461 	tilcdc_crtc_enable_irqs(dev);
462 
463 	tilcdc_clear(dev, LCDC_DMA_CTRL_REG, LCDC_DUAL_FRAME_BUFFER_ENABLE);
464 	tilcdc_write_mask(dev, LCDC_RASTER_CTRL_REG,
465 			  LCDC_PALETTE_LOAD_MODE(DATA_ONLY),
466 			  LCDC_PALETTE_LOAD_MODE_MASK);
467 
468 	/* There is no real chance for a race here as the time stamp
469 	 * is taken before the raster DMA is started. The spin-lock is
470 	 * taken to have a memory barrier after taking the time-stamp
471 	 * and to avoid a context switch between taking the stamp and
472 	 * enabling the raster.
473 	 */
474 	spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
475 	tilcdc_crtc->last_vblank = ktime_get();
476 	tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
477 	spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
478 
479 	drm_crtc_vblank_on(crtc);
480 
481 	tilcdc_crtc->enabled = true;
482 	mutex_unlock(&tilcdc_crtc->enable_lock);
483 }
484 
tilcdc_crtc_atomic_enable(struct drm_crtc * crtc,struct drm_atomic_state * state)485 static void tilcdc_crtc_atomic_enable(struct drm_crtc *crtc,
486 				      struct drm_atomic_state *state)
487 {
488 	tilcdc_crtc_enable(crtc);
489 }
490 
tilcdc_crtc_off(struct drm_crtc * crtc,bool shutdown)491 static void tilcdc_crtc_off(struct drm_crtc *crtc, bool shutdown)
492 {
493 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
494 	struct drm_device *dev = crtc->dev;
495 	int ret;
496 
497 	mutex_lock(&tilcdc_crtc->enable_lock);
498 	if (shutdown)
499 		tilcdc_crtc->shutdown = true;
500 	if (!tilcdc_crtc->enabled) {
501 		mutex_unlock(&tilcdc_crtc->enable_lock);
502 		return;
503 	}
504 	tilcdc_crtc->frame_done = false;
505 	tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
506 
507 	/*
508 	 * Wait for framedone irq which will still come before putting
509 	 * things to sleep..
510 	 */
511 	ret = wait_event_timeout(tilcdc_crtc->frame_done_wq,
512 				 tilcdc_crtc->frame_done,
513 				 msecs_to_jiffies(500));
514 	if (ret == 0)
515 		dev_err(dev->dev, "%s: timeout waiting for framedone\n",
516 			__func__);
517 
518 	drm_crtc_vblank_off(crtc);
519 
520 	spin_lock_irq(&crtc->dev->event_lock);
521 
522 	if (crtc->state->event) {
523 		drm_crtc_send_vblank_event(crtc, crtc->state->event);
524 		crtc->state->event = NULL;
525 	}
526 
527 	spin_unlock_irq(&crtc->dev->event_lock);
528 
529 	tilcdc_crtc_disable_irqs(dev);
530 
531 	pm_runtime_put_sync(dev->dev);
532 
533 	tilcdc_crtc->enabled = false;
534 	mutex_unlock(&tilcdc_crtc->enable_lock);
535 }
536 
tilcdc_crtc_disable(struct drm_crtc * crtc)537 static void tilcdc_crtc_disable(struct drm_crtc *crtc)
538 {
539 	tilcdc_crtc_off(crtc, false);
540 }
541 
tilcdc_crtc_atomic_disable(struct drm_crtc * crtc,struct drm_atomic_state * state)542 static void tilcdc_crtc_atomic_disable(struct drm_crtc *crtc,
543 				       struct drm_atomic_state *state)
544 {
545 	tilcdc_crtc_disable(crtc);
546 }
547 
tilcdc_crtc_atomic_flush(struct drm_crtc * crtc,struct drm_atomic_state * state)548 static void tilcdc_crtc_atomic_flush(struct drm_crtc *crtc,
549 				     struct drm_atomic_state *state)
550 {
551 	if (!crtc->state->event)
552 		return;
553 
554 	spin_lock_irq(&crtc->dev->event_lock);
555 	drm_crtc_send_vblank_event(crtc, crtc->state->event);
556 	crtc->state->event = NULL;
557 	spin_unlock_irq(&crtc->dev->event_lock);
558 }
559 
tilcdc_crtc_shutdown(struct drm_crtc * crtc)560 void tilcdc_crtc_shutdown(struct drm_crtc *crtc)
561 {
562 	tilcdc_crtc_off(crtc, true);
563 }
564 
tilcdc_crtc_is_on(struct drm_crtc * crtc)565 static bool tilcdc_crtc_is_on(struct drm_crtc *crtc)
566 {
567 	return crtc->state && crtc->state->enable && crtc->state->active;
568 }
569 
tilcdc_crtc_recover_work(struct work_struct * work)570 static void tilcdc_crtc_recover_work(struct work_struct *work)
571 {
572 	struct tilcdc_crtc *tilcdc_crtc =
573 		container_of(work, struct tilcdc_crtc, recover_work);
574 	struct drm_crtc *crtc = &tilcdc_crtc->base;
575 
576 	dev_info(crtc->dev->dev, "%s: Reset CRTC", __func__);
577 
578 	drm_modeset_lock(&crtc->mutex, NULL);
579 
580 	if (!tilcdc_crtc_is_on(crtc))
581 		goto out;
582 
583 	tilcdc_crtc_disable(crtc);
584 	tilcdc_crtc_enable(crtc);
585 out:
586 	drm_modeset_unlock(&crtc->mutex);
587 }
588 
tilcdc_crtc_destroy(struct drm_crtc * crtc)589 static void tilcdc_crtc_destroy(struct drm_crtc *crtc)
590 {
591 	struct tilcdc_drm_private *priv = crtc->dev->dev_private;
592 
593 	tilcdc_crtc_shutdown(crtc);
594 
595 	flush_workqueue(priv->wq);
596 
597 	of_node_put(crtc->port);
598 	drm_crtc_cleanup(crtc);
599 }
600 
tilcdc_crtc_update_fb(struct drm_crtc * crtc,struct drm_framebuffer * fb,struct drm_pending_vblank_event * event)601 int tilcdc_crtc_update_fb(struct drm_crtc *crtc,
602 		struct drm_framebuffer *fb,
603 		struct drm_pending_vblank_event *event)
604 {
605 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
606 	struct drm_device *dev = crtc->dev;
607 
608 	if (tilcdc_crtc->event) {
609 		dev_err(dev->dev, "already pending page flip!\n");
610 		return -EBUSY;
611 	}
612 
613 	tilcdc_crtc->event = event;
614 
615 	mutex_lock(&tilcdc_crtc->enable_lock);
616 
617 	if (tilcdc_crtc->enabled) {
618 		unsigned long flags;
619 		ktime_t next_vblank;
620 		s64 tdiff;
621 
622 		spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
623 
624 		next_vblank = ktime_add_us(tilcdc_crtc->last_vblank,
625 					   tilcdc_crtc->hvtotal_us);
626 		tdiff = ktime_to_us(ktime_sub(next_vblank, ktime_get()));
627 
628 		if (tdiff < TILCDC_VBLANK_SAFETY_THRESHOLD_US)
629 			tilcdc_crtc->next_fb = fb;
630 		else
631 			set_scanout(crtc, fb);
632 
633 		spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
634 	}
635 
636 	mutex_unlock(&tilcdc_crtc->enable_lock);
637 
638 	return 0;
639 }
640 
tilcdc_crtc_mode_fixup(struct drm_crtc * crtc,const struct drm_display_mode * mode,struct drm_display_mode * adjusted_mode)641 static bool tilcdc_crtc_mode_fixup(struct drm_crtc *crtc,
642 		const struct drm_display_mode *mode,
643 		struct drm_display_mode *adjusted_mode)
644 {
645 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
646 
647 	if (!tilcdc_crtc->simulate_vesa_sync)
648 		return true;
649 
650 	/*
651 	 * tilcdc does not generate VESA-compliant sync but aligns
652 	 * VS on the second edge of HS instead of first edge.
653 	 * We use adjusted_mode, to fixup sync by aligning both rising
654 	 * edges and add HSKEW offset to fix the sync.
655 	 */
656 	adjusted_mode->hskew = mode->hsync_end - mode->hsync_start;
657 	adjusted_mode->flags |= DRM_MODE_FLAG_HSKEW;
658 
659 	if (mode->flags & DRM_MODE_FLAG_NHSYNC) {
660 		adjusted_mode->flags |= DRM_MODE_FLAG_PHSYNC;
661 		adjusted_mode->flags &= ~DRM_MODE_FLAG_NHSYNC;
662 	} else {
663 		adjusted_mode->flags |= DRM_MODE_FLAG_NHSYNC;
664 		adjusted_mode->flags &= ~DRM_MODE_FLAG_PHSYNC;
665 	}
666 
667 	return true;
668 }
669 
tilcdc_crtc_atomic_check(struct drm_crtc * crtc,struct drm_atomic_state * state)670 static int tilcdc_crtc_atomic_check(struct drm_crtc *crtc,
671 				    struct drm_atomic_state *state)
672 {
673 	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
674 									  crtc);
675 	/* If we are not active we don't care */
676 	if (!crtc_state->active)
677 		return 0;
678 
679 	if (state->planes[0].ptr != crtc->primary ||
680 	    state->planes[0].state == NULL ||
681 	    state->planes[0].state->crtc != crtc) {
682 		dev_dbg(crtc->dev->dev, "CRTC primary plane must be present");
683 		return -EINVAL;
684 	}
685 
686 	return 0;
687 }
688 
tilcdc_crtc_enable_vblank(struct drm_crtc * crtc)689 static int tilcdc_crtc_enable_vblank(struct drm_crtc *crtc)
690 {
691 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
692 	struct drm_device *dev = crtc->dev;
693 	struct tilcdc_drm_private *priv = dev->dev_private;
694 	unsigned long flags;
695 
696 	spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
697 
698 	tilcdc_clear_irqstatus(dev, LCDC_END_OF_FRAME0);
699 
700 	if (priv->rev == 1)
701 		tilcdc_set(dev, LCDC_DMA_CTRL_REG,
702 			   LCDC_V1_END_OF_FRAME_INT_ENA);
703 	else
704 		tilcdc_set(dev, LCDC_INT_ENABLE_SET_REG,
705 			   LCDC_V2_END_OF_FRAME0_INT_ENA);
706 
707 	spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
708 
709 	return 0;
710 }
711 
tilcdc_crtc_disable_vblank(struct drm_crtc * crtc)712 static void tilcdc_crtc_disable_vblank(struct drm_crtc *crtc)
713 {
714 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
715 	struct drm_device *dev = crtc->dev;
716 	struct tilcdc_drm_private *priv = dev->dev_private;
717 	unsigned long flags;
718 
719 	spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
720 
721 	if (priv->rev == 1)
722 		tilcdc_clear(dev, LCDC_DMA_CTRL_REG,
723 			     LCDC_V1_END_OF_FRAME_INT_ENA);
724 	else
725 		tilcdc_clear(dev, LCDC_INT_ENABLE_SET_REG,
726 			     LCDC_V2_END_OF_FRAME0_INT_ENA);
727 
728 	spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
729 }
730 
tilcdc_crtc_reset(struct drm_crtc * crtc)731 static void tilcdc_crtc_reset(struct drm_crtc *crtc)
732 {
733 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
734 	struct drm_device *dev = crtc->dev;
735 	int ret;
736 
737 	drm_atomic_helper_crtc_reset(crtc);
738 
739 	/* Turn the raster off if it for some reason is on. */
740 	pm_runtime_get_sync(dev->dev);
741 	if (tilcdc_read(dev, LCDC_RASTER_CTRL_REG) & LCDC_RASTER_ENABLE) {
742 		/* Enable DMA Frame Done Interrupt */
743 		tilcdc_write(dev, LCDC_INT_ENABLE_SET_REG, LCDC_FRAME_DONE);
744 		tilcdc_clear_irqstatus(dev, 0xffffffff);
745 
746 		tilcdc_crtc->frame_done = false;
747 		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
748 
749 		ret = wait_event_timeout(tilcdc_crtc->frame_done_wq,
750 					 tilcdc_crtc->frame_done,
751 					 msecs_to_jiffies(500));
752 		if (ret == 0)
753 			dev_err(dev->dev, "%s: timeout waiting for framedone\n",
754 				__func__);
755 	}
756 	pm_runtime_put_sync(dev->dev);
757 }
758 
759 static const struct drm_crtc_funcs tilcdc_crtc_funcs = {
760 	.destroy        = tilcdc_crtc_destroy,
761 	.set_config     = drm_atomic_helper_set_config,
762 	.page_flip      = drm_atomic_helper_page_flip,
763 	.reset		= tilcdc_crtc_reset,
764 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
765 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
766 	.enable_vblank	= tilcdc_crtc_enable_vblank,
767 	.disable_vblank	= tilcdc_crtc_disable_vblank,
768 };
769 
770 static enum drm_mode_status
tilcdc_crtc_mode_valid(struct drm_crtc * crtc,const struct drm_display_mode * mode)771 tilcdc_crtc_mode_valid(struct drm_crtc *crtc,
772 		       const struct drm_display_mode *mode)
773 {
774 	struct tilcdc_drm_private *priv = crtc->dev->dev_private;
775 	unsigned int bandwidth;
776 	uint32_t hbp, hfp, hsw, vbp, vfp, vsw;
777 
778 	/*
779 	 * check to see if the width is within the range that
780 	 * the LCD Controller physically supports
781 	 */
782 	if (mode->hdisplay > priv->max_width)
783 		return MODE_VIRTUAL_X;
784 
785 	/* width must be multiple of 16 */
786 	if (mode->hdisplay & 0xf)
787 		return MODE_VIRTUAL_X;
788 
789 	if (mode->vdisplay > 2048)
790 		return MODE_VIRTUAL_Y;
791 
792 	DBG("Processing mode %dx%d@%d with pixel clock %d",
793 		mode->hdisplay, mode->vdisplay,
794 		drm_mode_vrefresh(mode), mode->clock);
795 
796 	hbp = mode->htotal - mode->hsync_end;
797 	hfp = mode->hsync_start - mode->hdisplay;
798 	hsw = mode->hsync_end - mode->hsync_start;
799 	vbp = mode->vtotal - mode->vsync_end;
800 	vfp = mode->vsync_start - mode->vdisplay;
801 	vsw = mode->vsync_end - mode->vsync_start;
802 
803 	if ((hbp-1) & ~0x3ff) {
804 		DBG("Pruning mode: Horizontal Back Porch out of range");
805 		return MODE_HBLANK_WIDE;
806 	}
807 
808 	if ((hfp-1) & ~0x3ff) {
809 		DBG("Pruning mode: Horizontal Front Porch out of range");
810 		return MODE_HBLANK_WIDE;
811 	}
812 
813 	if ((hsw-1) & ~0x3ff) {
814 		DBG("Pruning mode: Horizontal Sync Width out of range");
815 		return MODE_HSYNC_WIDE;
816 	}
817 
818 	if (vbp & ~0xff) {
819 		DBG("Pruning mode: Vertical Back Porch out of range");
820 		return MODE_VBLANK_WIDE;
821 	}
822 
823 	if (vfp & ~0xff) {
824 		DBG("Pruning mode: Vertical Front Porch out of range");
825 		return MODE_VBLANK_WIDE;
826 	}
827 
828 	if ((vsw-1) & ~0x3f) {
829 		DBG("Pruning mode: Vertical Sync Width out of range");
830 		return MODE_VSYNC_WIDE;
831 	}
832 
833 	/*
834 	 * some devices have a maximum allowed pixel clock
835 	 * configured from the DT
836 	 */
837 	if (mode->clock > priv->max_pixelclock) {
838 		DBG("Pruning mode: pixel clock too high");
839 		return MODE_CLOCK_HIGH;
840 	}
841 
842 	/*
843 	 * some devices further limit the max horizontal resolution
844 	 * configured from the DT
845 	 */
846 	if (mode->hdisplay > priv->max_width)
847 		return MODE_BAD_WIDTH;
848 
849 	/* filter out modes that would require too much memory bandwidth: */
850 	bandwidth = mode->hdisplay * mode->vdisplay *
851 		drm_mode_vrefresh(mode);
852 	if (bandwidth > priv->max_bandwidth) {
853 		DBG("Pruning mode: exceeds defined bandwidth limit");
854 		return MODE_BAD;
855 	}
856 
857 	return MODE_OK;
858 }
859 
860 static const struct drm_crtc_helper_funcs tilcdc_crtc_helper_funcs = {
861 	.mode_valid	= tilcdc_crtc_mode_valid,
862 	.mode_fixup	= tilcdc_crtc_mode_fixup,
863 	.atomic_check	= tilcdc_crtc_atomic_check,
864 	.atomic_enable	= tilcdc_crtc_atomic_enable,
865 	.atomic_disable	= tilcdc_crtc_atomic_disable,
866 	.atomic_flush	= tilcdc_crtc_atomic_flush,
867 };
868 
tilcdc_crtc_set_panel_info(struct drm_crtc * crtc,const struct tilcdc_panel_info * info)869 void tilcdc_crtc_set_panel_info(struct drm_crtc *crtc,
870 		const struct tilcdc_panel_info *info)
871 {
872 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
873 	tilcdc_crtc->info = info;
874 }
875 
tilcdc_crtc_set_simulate_vesa_sync(struct drm_crtc * crtc,bool simulate_vesa_sync)876 void tilcdc_crtc_set_simulate_vesa_sync(struct drm_crtc *crtc,
877 					bool simulate_vesa_sync)
878 {
879 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
880 
881 	tilcdc_crtc->simulate_vesa_sync = simulate_vesa_sync;
882 }
883 
tilcdc_crtc_update_clk(struct drm_crtc * crtc)884 void tilcdc_crtc_update_clk(struct drm_crtc *crtc)
885 {
886 	struct drm_device *dev = crtc->dev;
887 	struct tilcdc_drm_private *priv = dev->dev_private;
888 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
889 
890 	drm_modeset_lock(&crtc->mutex, NULL);
891 	if (tilcdc_crtc->lcd_fck_rate != clk_get_rate(priv->clk)) {
892 		if (tilcdc_crtc_is_on(crtc)) {
893 			pm_runtime_get_sync(dev->dev);
894 			tilcdc_crtc_disable(crtc);
895 
896 			tilcdc_crtc_set_clk(crtc);
897 
898 			tilcdc_crtc_enable(crtc);
899 			pm_runtime_put_sync(dev->dev);
900 		}
901 	}
902 	drm_modeset_unlock(&crtc->mutex);
903 }
904 
905 #define SYNC_LOST_COUNT_LIMIT 50
906 
tilcdc_crtc_irq(struct drm_crtc * crtc)907 irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
908 {
909 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
910 	struct drm_device *dev = crtc->dev;
911 	struct tilcdc_drm_private *priv = dev->dev_private;
912 	uint32_t stat, reg;
913 
914 	stat = tilcdc_read_irqstatus(dev);
915 	tilcdc_clear_irqstatus(dev, stat);
916 
917 	if (stat & LCDC_END_OF_FRAME0) {
918 		bool skip_event = false;
919 		ktime_t now;
920 
921 		now = ktime_get();
922 
923 		spin_lock(&tilcdc_crtc->irq_lock);
924 
925 		tilcdc_crtc->last_vblank = now;
926 
927 		if (tilcdc_crtc->next_fb) {
928 			set_scanout(crtc, tilcdc_crtc->next_fb);
929 			tilcdc_crtc->next_fb = NULL;
930 			skip_event = true;
931 		}
932 
933 		spin_unlock(&tilcdc_crtc->irq_lock);
934 
935 		drm_crtc_handle_vblank(crtc);
936 
937 		if (!skip_event) {
938 			struct drm_pending_vblank_event *event;
939 
940 			spin_lock(&dev->event_lock);
941 
942 			event = tilcdc_crtc->event;
943 			tilcdc_crtc->event = NULL;
944 			if (event)
945 				drm_crtc_send_vblank_event(crtc, event);
946 
947 			spin_unlock(&dev->event_lock);
948 		}
949 
950 		if (tilcdc_crtc->frame_intact)
951 			tilcdc_crtc->sync_lost_count = 0;
952 		else
953 			tilcdc_crtc->frame_intact = true;
954 	}
955 
956 	if (stat & LCDC_FIFO_UNDERFLOW)
957 		dev_err_ratelimited(dev->dev, "%s(0x%08x): FIFO underflow",
958 				    __func__, stat);
959 
960 	if (stat & LCDC_PL_LOAD_DONE) {
961 		complete(&tilcdc_crtc->palette_loaded);
962 		if (priv->rev == 1)
963 			tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
964 				     LCDC_V1_PL_INT_ENA);
965 		else
966 			tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
967 				     LCDC_V2_PL_INT_ENA);
968 	}
969 
970 	if (stat & LCDC_SYNC_LOST) {
971 		dev_err_ratelimited(dev->dev, "%s(0x%08x): Sync lost",
972 				    __func__, stat);
973 		tilcdc_crtc->frame_intact = false;
974 		if (priv->rev == 1) {
975 			reg = tilcdc_read(dev, LCDC_RASTER_CTRL_REG);
976 			if (reg & LCDC_RASTER_ENABLE) {
977 				tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
978 					     LCDC_RASTER_ENABLE);
979 				tilcdc_set(dev, LCDC_RASTER_CTRL_REG,
980 					   LCDC_RASTER_ENABLE);
981 			}
982 		} else {
983 			if (tilcdc_crtc->sync_lost_count++ >
984 			    SYNC_LOST_COUNT_LIMIT) {
985 				dev_err(dev->dev,
986 					"%s(0x%08x): Sync lost flood detected, recovering",
987 					__func__, stat);
988 				queue_work(system_wq,
989 					   &tilcdc_crtc->recover_work);
990 				tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
991 					     LCDC_SYNC_LOST);
992 				tilcdc_crtc->sync_lost_count = 0;
993 			}
994 		}
995 	}
996 
997 	if (stat & LCDC_FRAME_DONE) {
998 		tilcdc_crtc->frame_done = true;
999 		wake_up(&tilcdc_crtc->frame_done_wq);
1000 		/* rev 1 lcdc appears to hang if irq is not disabled here */
1001 		if (priv->rev == 1)
1002 			tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
1003 				     LCDC_V1_FRAME_DONE_INT_ENA);
1004 	}
1005 
1006 	/* For revision 2 only */
1007 	if (priv->rev == 2) {
1008 		/* Indicate to LCDC that the interrupt service routine has
1009 		 * completed, see 13.3.6.1.6 in AM335x TRM.
1010 		 */
1011 		tilcdc_write(dev, LCDC_END_OF_INT_IND_REG, 0);
1012 	}
1013 
1014 	return IRQ_HANDLED;
1015 }
1016 
tilcdc_crtc_create(struct drm_device * dev)1017 int tilcdc_crtc_create(struct drm_device *dev)
1018 {
1019 	struct tilcdc_drm_private *priv = dev->dev_private;
1020 	struct tilcdc_crtc *tilcdc_crtc;
1021 	struct drm_crtc *crtc;
1022 	int ret;
1023 
1024 	tilcdc_crtc = devm_kzalloc(dev->dev, sizeof(*tilcdc_crtc), GFP_KERNEL);
1025 	if (!tilcdc_crtc)
1026 		return -ENOMEM;
1027 
1028 	init_completion(&tilcdc_crtc->palette_loaded);
1029 	tilcdc_crtc->palette_base = dmam_alloc_coherent(dev->dev,
1030 					TILCDC_PALETTE_SIZE,
1031 					&tilcdc_crtc->palette_dma_handle,
1032 					GFP_KERNEL | __GFP_ZERO);
1033 	if (!tilcdc_crtc->palette_base)
1034 		return -ENOMEM;
1035 	*tilcdc_crtc->palette_base = TILCDC_PALETTE_FIRST_ENTRY;
1036 
1037 	crtc = &tilcdc_crtc->base;
1038 
1039 	ret = tilcdc_plane_init(dev, &tilcdc_crtc->primary);
1040 	if (ret < 0)
1041 		goto fail;
1042 
1043 	mutex_init(&tilcdc_crtc->enable_lock);
1044 
1045 	init_waitqueue_head(&tilcdc_crtc->frame_done_wq);
1046 
1047 	spin_lock_init(&tilcdc_crtc->irq_lock);
1048 	INIT_WORK(&tilcdc_crtc->recover_work, tilcdc_crtc_recover_work);
1049 
1050 	ret = drm_crtc_init_with_planes(dev, crtc,
1051 					&tilcdc_crtc->primary,
1052 					NULL,
1053 					&tilcdc_crtc_funcs,
1054 					"tilcdc crtc");
1055 	if (ret < 0)
1056 		goto fail;
1057 
1058 	drm_crtc_helper_add(crtc, &tilcdc_crtc_helper_funcs);
1059 
1060 	if (priv->is_componentized) {
1061 		crtc->port = of_graph_get_port_by_id(dev->dev->of_node, 0);
1062 		if (!crtc->port) { /* This should never happen */
1063 			dev_err(dev->dev, "Port node not found in %pOF\n",
1064 				dev->dev->of_node);
1065 			ret = -EINVAL;
1066 			goto fail;
1067 		}
1068 	}
1069 
1070 	priv->crtc = crtc;
1071 	return 0;
1072 
1073 fail:
1074 	tilcdc_crtc_destroy(crtc);
1075 	return ret;
1076 }
1077