xref: /openbmc/linux/drivers/gpu/drm/pl111/pl111_display.c (revision 6396bb221514d2876fd6dc0aa2a1f240d99b37bb)
1 /*
2  * (C) COPYRIGHT 2012-2013 ARM Limited. All rights reserved.
3  *
4  * Parts of this file were based on sources as follows:
5  *
6  * Copyright (c) 2006-2008 Intel Corporation
7  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
8  * Copyright (C) 2011 Texas Instruments
9  *
10  * This program is free software and is provided to you under the terms of the
11  * GNU General Public License version 2 as published by the Free Software
12  * Foundation, and any use by you of this program is subject to the terms of
13  * such GNU licence.
14  *
15  */
16 
17 #include <linux/amba/clcd-regs.h>
18 #include <linux/clk.h>
19 #include <linux/version.h>
20 #include <linux/dma-buf.h>
21 #include <linux/of_graph.h>
22 
23 #include <drm/drmP.h>
24 #include <drm/drm_gem_cma_helper.h>
25 #include <drm/drm_gem_framebuffer_helper.h>
26 #include <drm/drm_fb_cma_helper.h>
27 
28 #include "pl111_drm.h"
29 
30 irqreturn_t pl111_irq(int irq, void *data)
31 {
32 	struct pl111_drm_dev_private *priv = data;
33 	u32 irq_stat;
34 	irqreturn_t status = IRQ_NONE;
35 
36 	irq_stat = readl(priv->regs + CLCD_PL111_MIS);
37 
38 	if (!irq_stat)
39 		return IRQ_NONE;
40 
41 	if (irq_stat & CLCD_IRQ_NEXTBASE_UPDATE) {
42 		drm_crtc_handle_vblank(&priv->pipe.crtc);
43 
44 		status = IRQ_HANDLED;
45 	}
46 
47 	/* Clear the interrupt once done */
48 	writel(irq_stat, priv->regs + CLCD_PL111_ICR);
49 
50 	return status;
51 }
52 
53 static enum drm_mode_status
54 pl111_mode_valid(struct drm_crtc *crtc,
55 		 const struct drm_display_mode *mode)
56 {
57 	struct drm_device *drm = crtc->dev;
58 	struct pl111_drm_dev_private *priv = drm->dev_private;
59 	u32 cpp = priv->variant->fb_bpp / 8;
60 	u64 bw;
61 
62 	/*
63 	 * We use the pixelclock to also account for interlaced modes, the
64 	 * resulting bandwidth is in bytes per second.
65 	 */
66 	bw = mode->clock * 1000; /* In Hz */
67 	bw = bw * mode->hdisplay * mode->vdisplay * cpp;
68 	bw = div_u64(bw, mode->htotal * mode->vtotal);
69 
70 	/*
71 	 * If no bandwidth constraints, anything goes, else
72 	 * check if we are too fast.
73 	 */
74 	if (priv->memory_bw && (bw > priv->memory_bw)) {
75 		DRM_DEBUG_KMS("%d x %d @ %d Hz, %d cpp, bw %llu too fast\n",
76 			      mode->hdisplay, mode->vdisplay,
77 			      mode->clock * 1000, cpp, bw);
78 
79 		return MODE_BAD;
80 	}
81 	DRM_DEBUG_KMS("%d x %d @ %d Hz, %d cpp, bw %llu bytes/s OK\n",
82 		      mode->hdisplay, mode->vdisplay,
83 		      mode->clock * 1000, cpp, bw);
84 
85 	return MODE_OK;
86 }
87 
88 static int pl111_display_check(struct drm_simple_display_pipe *pipe,
89 			       struct drm_plane_state *pstate,
90 			       struct drm_crtc_state *cstate)
91 {
92 	const struct drm_display_mode *mode = &cstate->mode;
93 	struct drm_framebuffer *old_fb = pipe->plane.state->fb;
94 	struct drm_framebuffer *fb = pstate->fb;
95 
96 	if (mode->hdisplay % 16)
97 		return -EINVAL;
98 
99 	if (fb) {
100 		u32 offset = drm_fb_cma_get_gem_addr(fb, pstate, 0);
101 
102 		/* FB base address must be dword aligned. */
103 		if (offset & 3)
104 			return -EINVAL;
105 
106 		/* There's no pitch register -- the mode's hdisplay
107 		 * controls it.
108 		 */
109 		if (fb->pitches[0] != mode->hdisplay * fb->format->cpp[0])
110 			return -EINVAL;
111 
112 		/* We can't change the FB format in a flicker-free
113 		 * manner (and only update it during CRTC enable).
114 		 */
115 		if (old_fb && old_fb->format != fb->format)
116 			cstate->mode_changed = true;
117 	}
118 
119 	return 0;
120 }
121 
122 static void pl111_display_enable(struct drm_simple_display_pipe *pipe,
123 				 struct drm_crtc_state *cstate,
124 				 struct drm_plane_state *plane_state)
125 {
126 	struct drm_crtc *crtc = &pipe->crtc;
127 	struct drm_plane *plane = &pipe->plane;
128 	struct drm_device *drm = crtc->dev;
129 	struct pl111_drm_dev_private *priv = drm->dev_private;
130 	const struct drm_display_mode *mode = &cstate->mode;
131 	struct drm_framebuffer *fb = plane->state->fb;
132 	struct drm_connector *connector = priv->connector;
133 	struct drm_bridge *bridge = priv->bridge;
134 	u32 cntl;
135 	u32 ppl, hsw, hfp, hbp;
136 	u32 lpp, vsw, vfp, vbp;
137 	u32 cpl, tim2;
138 	int ret;
139 
140 	ret = clk_set_rate(priv->clk, mode->clock * 1000);
141 	if (ret) {
142 		dev_err(drm->dev,
143 			"Failed to set pixel clock rate to %d: %d\n",
144 			mode->clock * 1000, ret);
145 	}
146 
147 	clk_prepare_enable(priv->clk);
148 
149 	ppl = (mode->hdisplay / 16) - 1;
150 	hsw = mode->hsync_end - mode->hsync_start - 1;
151 	hfp = mode->hsync_start - mode->hdisplay - 1;
152 	hbp = mode->htotal - mode->hsync_end - 1;
153 
154 	lpp = mode->vdisplay - 1;
155 	vsw = mode->vsync_end - mode->vsync_start - 1;
156 	vfp = mode->vsync_start - mode->vdisplay;
157 	vbp = mode->vtotal - mode->vsync_end;
158 
159 	cpl = mode->hdisplay - 1;
160 
161 	writel((ppl << 2) |
162 	       (hsw << 8) |
163 	       (hfp << 16) |
164 	       (hbp << 24),
165 	       priv->regs + CLCD_TIM0);
166 	writel(lpp |
167 	       (vsw << 10) |
168 	       (vfp << 16) |
169 	       (vbp << 24),
170 	       priv->regs + CLCD_TIM1);
171 
172 	spin_lock(&priv->tim2_lock);
173 
174 	tim2 = readl(priv->regs + CLCD_TIM2);
175 	tim2 &= (TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
176 
177 	if (priv->variant->broken_clockdivider)
178 		tim2 |= TIM2_BCD;
179 
180 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
181 		tim2 |= TIM2_IHS;
182 
183 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
184 		tim2 |= TIM2_IVS;
185 
186 	if (connector) {
187 		if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
188 			tim2 |= TIM2_IOE;
189 
190 		if (connector->display_info.bus_flags &
191 		    DRM_BUS_FLAG_PIXDATA_NEGEDGE)
192 			tim2 |= TIM2_IPC;
193 	}
194 
195 	if (bridge) {
196 		const struct drm_bridge_timings *btimings = bridge->timings;
197 
198 		/*
199 		 * Here is when things get really fun. Sometimes the bridge
200 		 * timings are such that the signal out from PL11x is not
201 		 * stable before the receiving bridge (such as a dumb VGA DAC
202 		 * or similar) samples it. If that happens, we compensate by
203 		 * the only method we have: output the data on the opposite
204 		 * edge of the clock so it is for sure stable when it gets
205 		 * sampled.
206 		 *
207 		 * The PL111 manual does not contain proper timining diagrams
208 		 * or data for these details, but we know from experiments
209 		 * that the setup time is more than 3000 picoseconds (3 ns).
210 		 * If we have a bridge that requires the signal to be stable
211 		 * earlier than 3000 ps before the clock pulse, we have to
212 		 * output the data on the opposite edge to avoid flicker.
213 		 */
214 		if (btimings && btimings->setup_time_ps >= 3000)
215 			tim2 ^= TIM2_IPC;
216 	}
217 
218 	tim2 |= cpl << 16;
219 	writel(tim2, priv->regs + CLCD_TIM2);
220 	spin_unlock(&priv->tim2_lock);
221 
222 	writel(0, priv->regs + CLCD_TIM3);
223 
224 	/* Hard-code TFT panel */
225 	cntl = CNTL_LCDEN | CNTL_LCDTFT | CNTL_LCDVCOMP(1);
226 
227 	/* Note that the the hardware's format reader takes 'r' from
228 	 * the low bit, while DRM formats list channels from high bit
229 	 * to low bit as you read left to right.
230 	 */
231 	switch (fb->format->format) {
232 	case DRM_FORMAT_ABGR8888:
233 	case DRM_FORMAT_XBGR8888:
234 		cntl |= CNTL_LCDBPP24;
235 		break;
236 	case DRM_FORMAT_ARGB8888:
237 	case DRM_FORMAT_XRGB8888:
238 		cntl |= CNTL_LCDBPP24 | CNTL_BGR;
239 		break;
240 	case DRM_FORMAT_BGR565:
241 		if (priv->variant->is_pl110)
242 			cntl |= CNTL_LCDBPP16;
243 		else
244 			cntl |= CNTL_LCDBPP16_565;
245 		break;
246 	case DRM_FORMAT_RGB565:
247 		if (priv->variant->is_pl110)
248 			cntl |= CNTL_LCDBPP16;
249 		else
250 			cntl |= CNTL_LCDBPP16_565;
251 		cntl |= CNTL_BGR;
252 		break;
253 	case DRM_FORMAT_ABGR1555:
254 	case DRM_FORMAT_XBGR1555:
255 		cntl |= CNTL_LCDBPP16;
256 		break;
257 	case DRM_FORMAT_ARGB1555:
258 	case DRM_FORMAT_XRGB1555:
259 		cntl |= CNTL_LCDBPP16 | CNTL_BGR;
260 		break;
261 	case DRM_FORMAT_ABGR4444:
262 	case DRM_FORMAT_XBGR4444:
263 		cntl |= CNTL_LCDBPP16_444;
264 		break;
265 	case DRM_FORMAT_ARGB4444:
266 	case DRM_FORMAT_XRGB4444:
267 		cntl |= CNTL_LCDBPP16_444 | CNTL_BGR;
268 		break;
269 	default:
270 		WARN_ONCE(true, "Unknown FB format 0x%08x\n",
271 			  fb->format->format);
272 		break;
273 	}
274 
275 	/* The PL110 in Integrator/Versatile does the BGR routing externally */
276 	if (priv->variant->external_bgr)
277 		cntl &= ~CNTL_BGR;
278 
279 	/* Power sequence: first enable and chill */
280 	writel(cntl, priv->regs + priv->ctrl);
281 
282 	/*
283 	 * We expect this delay to stabilize the contrast
284 	 * voltage Vee as stipulated by the manual
285 	 */
286 	msleep(20);
287 
288 	if (priv->variant_display_enable)
289 		priv->variant_display_enable(drm, fb->format->format);
290 
291 	/* Power Up */
292 	cntl |= CNTL_LCDPWR;
293 	writel(cntl, priv->regs + priv->ctrl);
294 
295 	if (!priv->variant->broken_vblank)
296 		drm_crtc_vblank_on(crtc);
297 }
298 
299 void pl111_display_disable(struct drm_simple_display_pipe *pipe)
300 {
301 	struct drm_crtc *crtc = &pipe->crtc;
302 	struct drm_device *drm = crtc->dev;
303 	struct pl111_drm_dev_private *priv = drm->dev_private;
304 	u32 cntl;
305 
306 	if (!priv->variant->broken_vblank)
307 		drm_crtc_vblank_off(crtc);
308 
309 	/* Power Down */
310 	cntl = readl(priv->regs + priv->ctrl);
311 	if (cntl & CNTL_LCDPWR) {
312 		cntl &= ~CNTL_LCDPWR;
313 		writel(cntl, priv->regs + priv->ctrl);
314 	}
315 
316 	/*
317 	 * We expect this delay to stabilize the contrast voltage Vee as
318 	 * stipulated by the manual
319 	 */
320 	msleep(20);
321 
322 	if (priv->variant_display_disable)
323 		priv->variant_display_disable(drm);
324 
325 	/* Disable */
326 	writel(0, priv->regs + priv->ctrl);
327 
328 	clk_disable_unprepare(priv->clk);
329 }
330 
331 static void pl111_display_update(struct drm_simple_display_pipe *pipe,
332 				 struct drm_plane_state *old_pstate)
333 {
334 	struct drm_crtc *crtc = &pipe->crtc;
335 	struct drm_device *drm = crtc->dev;
336 	struct pl111_drm_dev_private *priv = drm->dev_private;
337 	struct drm_pending_vblank_event *event = crtc->state->event;
338 	struct drm_plane *plane = &pipe->plane;
339 	struct drm_plane_state *pstate = plane->state;
340 	struct drm_framebuffer *fb = pstate->fb;
341 
342 	if (fb) {
343 		u32 addr = drm_fb_cma_get_gem_addr(fb, pstate, 0);
344 
345 		writel(addr, priv->regs + CLCD_UBAS);
346 	}
347 
348 	if (event) {
349 		crtc->state->event = NULL;
350 
351 		spin_lock_irq(&crtc->dev->event_lock);
352 		if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
353 			drm_crtc_arm_vblank_event(crtc, event);
354 		else
355 			drm_crtc_send_vblank_event(crtc, event);
356 		spin_unlock_irq(&crtc->dev->event_lock);
357 	}
358 }
359 
360 static int pl111_display_enable_vblank(struct drm_simple_display_pipe *pipe)
361 {
362 	struct drm_crtc *crtc = &pipe->crtc;
363 	struct drm_device *drm = crtc->dev;
364 	struct pl111_drm_dev_private *priv = drm->dev_private;
365 
366 	writel(CLCD_IRQ_NEXTBASE_UPDATE, priv->regs + priv->ienb);
367 
368 	return 0;
369 }
370 
371 static void pl111_display_disable_vblank(struct drm_simple_display_pipe *pipe)
372 {
373 	struct drm_crtc *crtc = &pipe->crtc;
374 	struct drm_device *drm = crtc->dev;
375 	struct pl111_drm_dev_private *priv = drm->dev_private;
376 
377 	writel(0, priv->regs + priv->ienb);
378 }
379 
380 static struct drm_simple_display_pipe_funcs pl111_display_funcs = {
381 	.mode_valid = pl111_mode_valid,
382 	.check = pl111_display_check,
383 	.enable = pl111_display_enable,
384 	.disable = pl111_display_disable,
385 	.update = pl111_display_update,
386 	.prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
387 };
388 
389 static int pl111_clk_div_choose_div(struct clk_hw *hw, unsigned long rate,
390 				    unsigned long *prate, bool set_parent)
391 {
392 	int best_div = 1, div;
393 	struct clk_hw *parent = clk_hw_get_parent(hw);
394 	unsigned long best_prate = 0;
395 	unsigned long best_diff = ~0ul;
396 	int max_div = (1 << (TIM2_PCD_LO_BITS + TIM2_PCD_HI_BITS)) - 1;
397 
398 	for (div = 1; div < max_div; div++) {
399 		unsigned long this_prate, div_rate, diff;
400 
401 		if (set_parent)
402 			this_prate = clk_hw_round_rate(parent, rate * div);
403 		else
404 			this_prate = *prate;
405 		div_rate = DIV_ROUND_UP_ULL(this_prate, div);
406 		diff = abs(rate - div_rate);
407 
408 		if (diff < best_diff) {
409 			best_div = div;
410 			best_diff = diff;
411 			best_prate = this_prate;
412 		}
413 	}
414 
415 	*prate = best_prate;
416 	return best_div;
417 }
418 
419 static long pl111_clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
420 				     unsigned long *prate)
421 {
422 	int div = pl111_clk_div_choose_div(hw, rate, prate, true);
423 
424 	return DIV_ROUND_UP_ULL(*prate, div);
425 }
426 
427 static unsigned long pl111_clk_div_recalc_rate(struct clk_hw *hw,
428 					       unsigned long prate)
429 {
430 	struct pl111_drm_dev_private *priv =
431 		container_of(hw, struct pl111_drm_dev_private, clk_div);
432 	u32 tim2 = readl(priv->regs + CLCD_TIM2);
433 	int div;
434 
435 	if (tim2 & TIM2_BCD)
436 		return prate;
437 
438 	div = tim2 & TIM2_PCD_LO_MASK;
439 	div |= (tim2 & TIM2_PCD_HI_MASK) >>
440 		(TIM2_PCD_HI_SHIFT - TIM2_PCD_LO_BITS);
441 	div += 2;
442 
443 	return DIV_ROUND_UP_ULL(prate, div);
444 }
445 
446 static int pl111_clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
447 				  unsigned long prate)
448 {
449 	struct pl111_drm_dev_private *priv =
450 		container_of(hw, struct pl111_drm_dev_private, clk_div);
451 	int div = pl111_clk_div_choose_div(hw, rate, &prate, false);
452 	u32 tim2;
453 
454 	spin_lock(&priv->tim2_lock);
455 	tim2 = readl(priv->regs + CLCD_TIM2);
456 	tim2 &= ~(TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
457 
458 	if (div == 1) {
459 		tim2 |= TIM2_BCD;
460 	} else {
461 		div -= 2;
462 		tim2 |= div & TIM2_PCD_LO_MASK;
463 		tim2 |= (div >> TIM2_PCD_LO_BITS) << TIM2_PCD_HI_SHIFT;
464 	}
465 
466 	writel(tim2, priv->regs + CLCD_TIM2);
467 	spin_unlock(&priv->tim2_lock);
468 
469 	return 0;
470 }
471 
472 static const struct clk_ops pl111_clk_div_ops = {
473 	.recalc_rate = pl111_clk_div_recalc_rate,
474 	.round_rate = pl111_clk_div_round_rate,
475 	.set_rate = pl111_clk_div_set_rate,
476 };
477 
478 static int
479 pl111_init_clock_divider(struct drm_device *drm)
480 {
481 	struct pl111_drm_dev_private *priv = drm->dev_private;
482 	struct clk *parent = devm_clk_get(drm->dev, "clcdclk");
483 	struct clk_hw *div = &priv->clk_div;
484 	const char *parent_name;
485 	struct clk_init_data init = {
486 		.name = "pl111_div",
487 		.ops = &pl111_clk_div_ops,
488 		.parent_names = &parent_name,
489 		.num_parents = 1,
490 		.flags = CLK_SET_RATE_PARENT,
491 	};
492 	int ret;
493 
494 	if (IS_ERR(parent)) {
495 		dev_err(drm->dev, "CLCD: unable to get clcdclk.\n");
496 		return PTR_ERR(parent);
497 	}
498 	/* If the clock divider is broken, use the parent directly */
499 	if (priv->variant->broken_clockdivider) {
500 		priv->clk = parent;
501 		return 0;
502 	}
503 	parent_name = __clk_get_name(parent);
504 
505 	spin_lock_init(&priv->tim2_lock);
506 	div->init = &init;
507 
508 	ret = devm_clk_hw_register(drm->dev, div);
509 
510 	priv->clk = div->clk;
511 	return ret;
512 }
513 
514 int pl111_display_init(struct drm_device *drm)
515 {
516 	struct pl111_drm_dev_private *priv = drm->dev_private;
517 	struct device *dev = drm->dev;
518 	struct device_node *endpoint;
519 	u32 tft_r0b0g0[3];
520 	int ret;
521 
522 	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
523 	if (!endpoint)
524 		return -ENODEV;
525 
526 	if (of_property_read_u32_array(endpoint,
527 				       "arm,pl11x,tft-r0g0b0-pads",
528 				       tft_r0b0g0,
529 				       ARRAY_SIZE(tft_r0b0g0)) != 0) {
530 		dev_err(dev, "arm,pl11x,tft-r0g0b0-pads should be 3 ints\n");
531 		of_node_put(endpoint);
532 		return -ENOENT;
533 	}
534 	of_node_put(endpoint);
535 
536 	ret = pl111_init_clock_divider(drm);
537 	if (ret)
538 		return ret;
539 
540 	if (!priv->variant->broken_vblank) {
541 		pl111_display_funcs.enable_vblank = pl111_display_enable_vblank;
542 		pl111_display_funcs.disable_vblank = pl111_display_disable_vblank;
543 	}
544 
545 	ret = drm_simple_display_pipe_init(drm, &priv->pipe,
546 					   &pl111_display_funcs,
547 					   priv->variant->formats,
548 					   priv->variant->nformats,
549 					   NULL,
550 					   priv->connector);
551 	if (ret)
552 		return ret;
553 
554 	return 0;
555 }
556