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 * 1000ULL; /* 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_DRIVE_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 	/* On the ST Micro variant, assume all 24 bits are connected */
227 	if (priv->variant->st_bitmux_control)
228 		cntl |= CNTL_ST_CDWID_24;
229 
230 	/*
231 	 * Note that the the ARM hardware's format reader takes 'r' from
232 	 * the low bit, while DRM formats list channels from high bit
233 	 * to low bit as you read left to right. The ST Micro version of
234 	 * the PL110 (LCDC) however uses the standard DRM format.
235 	 */
236 	switch (fb->format->format) {
237 	case DRM_FORMAT_BGR888:
238 		/* Only supported on the ST Micro variant */
239 		if (priv->variant->st_bitmux_control)
240 			cntl |= CNTL_ST_LCDBPP24_PACKED | CNTL_BGR;
241 		break;
242 	case DRM_FORMAT_RGB888:
243 		/* Only supported on the ST Micro variant */
244 		if (priv->variant->st_bitmux_control)
245 			cntl |= CNTL_ST_LCDBPP24_PACKED;
246 		break;
247 	case DRM_FORMAT_ABGR8888:
248 	case DRM_FORMAT_XBGR8888:
249 		if (priv->variant->st_bitmux_control)
250 			cntl |= CNTL_LCDBPP24 | CNTL_BGR;
251 		else
252 			cntl |= CNTL_LCDBPP24;
253 		break;
254 	case DRM_FORMAT_ARGB8888:
255 	case DRM_FORMAT_XRGB8888:
256 		if (priv->variant->st_bitmux_control)
257 			cntl |= CNTL_LCDBPP24;
258 		else
259 			cntl |= CNTL_LCDBPP24 | CNTL_BGR;
260 		break;
261 	case DRM_FORMAT_BGR565:
262 		if (priv->variant->is_pl110)
263 			cntl |= CNTL_LCDBPP16;
264 		else if (priv->variant->st_bitmux_control)
265 			cntl |= CNTL_LCDBPP16 | CNTL_ST_1XBPP_565 | CNTL_BGR;
266 		else
267 			cntl |= CNTL_LCDBPP16_565;
268 		break;
269 	case DRM_FORMAT_RGB565:
270 		if (priv->variant->is_pl110)
271 			cntl |= CNTL_LCDBPP16 | CNTL_BGR;
272 		else if (priv->variant->st_bitmux_control)
273 			cntl |= CNTL_LCDBPP16 | CNTL_ST_1XBPP_565;
274 		else
275 			cntl |= CNTL_LCDBPP16_565 | CNTL_BGR;
276 		break;
277 	case DRM_FORMAT_ABGR1555:
278 	case DRM_FORMAT_XBGR1555:
279 		cntl |= CNTL_LCDBPP16;
280 		if (priv->variant->st_bitmux_control)
281 			cntl |= CNTL_ST_1XBPP_5551 | CNTL_BGR;
282 		break;
283 	case DRM_FORMAT_ARGB1555:
284 	case DRM_FORMAT_XRGB1555:
285 		cntl |= CNTL_LCDBPP16;
286 		if (priv->variant->st_bitmux_control)
287 			cntl |= CNTL_ST_1XBPP_5551;
288 		else
289 			cntl |= CNTL_BGR;
290 		break;
291 	case DRM_FORMAT_ABGR4444:
292 	case DRM_FORMAT_XBGR4444:
293 		cntl |= CNTL_LCDBPP16_444;
294 		if (priv->variant->st_bitmux_control)
295 			cntl |= CNTL_ST_1XBPP_444 | CNTL_BGR;
296 		break;
297 	case DRM_FORMAT_ARGB4444:
298 	case DRM_FORMAT_XRGB4444:
299 		cntl |= CNTL_LCDBPP16_444;
300 		if (priv->variant->st_bitmux_control)
301 			cntl |= CNTL_ST_1XBPP_444;
302 		else
303 			cntl |= CNTL_BGR;
304 		break;
305 	default:
306 		WARN_ONCE(true, "Unknown FB format 0x%08x\n",
307 			  fb->format->format);
308 		break;
309 	}
310 
311 	/* The PL110 in Integrator/Versatile does the BGR routing externally */
312 	if (priv->variant->external_bgr)
313 		cntl &= ~CNTL_BGR;
314 
315 	/* Power sequence: first enable and chill */
316 	writel(cntl, priv->regs + priv->ctrl);
317 
318 	/*
319 	 * We expect this delay to stabilize the contrast
320 	 * voltage Vee as stipulated by the manual
321 	 */
322 	msleep(20);
323 
324 	if (priv->variant_display_enable)
325 		priv->variant_display_enable(drm, fb->format->format);
326 
327 	/* Power Up */
328 	cntl |= CNTL_LCDPWR;
329 	writel(cntl, priv->regs + priv->ctrl);
330 
331 	if (!priv->variant->broken_vblank)
332 		drm_crtc_vblank_on(crtc);
333 }
334 
335 void pl111_display_disable(struct drm_simple_display_pipe *pipe)
336 {
337 	struct drm_crtc *crtc = &pipe->crtc;
338 	struct drm_device *drm = crtc->dev;
339 	struct pl111_drm_dev_private *priv = drm->dev_private;
340 	u32 cntl;
341 
342 	if (!priv->variant->broken_vblank)
343 		drm_crtc_vblank_off(crtc);
344 
345 	/* Power Down */
346 	cntl = readl(priv->regs + priv->ctrl);
347 	if (cntl & CNTL_LCDPWR) {
348 		cntl &= ~CNTL_LCDPWR;
349 		writel(cntl, priv->regs + priv->ctrl);
350 	}
351 
352 	/*
353 	 * We expect this delay to stabilize the contrast voltage Vee as
354 	 * stipulated by the manual
355 	 */
356 	msleep(20);
357 
358 	if (priv->variant_display_disable)
359 		priv->variant_display_disable(drm);
360 
361 	/* Disable */
362 	writel(0, priv->regs + priv->ctrl);
363 
364 	clk_disable_unprepare(priv->clk);
365 }
366 
367 static void pl111_display_update(struct drm_simple_display_pipe *pipe,
368 				 struct drm_plane_state *old_pstate)
369 {
370 	struct drm_crtc *crtc = &pipe->crtc;
371 	struct drm_device *drm = crtc->dev;
372 	struct pl111_drm_dev_private *priv = drm->dev_private;
373 	struct drm_pending_vblank_event *event = crtc->state->event;
374 	struct drm_plane *plane = &pipe->plane;
375 	struct drm_plane_state *pstate = plane->state;
376 	struct drm_framebuffer *fb = pstate->fb;
377 
378 	if (fb) {
379 		u32 addr = drm_fb_cma_get_gem_addr(fb, pstate, 0);
380 
381 		writel(addr, priv->regs + CLCD_UBAS);
382 	}
383 
384 	if (event) {
385 		crtc->state->event = NULL;
386 
387 		spin_lock_irq(&crtc->dev->event_lock);
388 		if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
389 			drm_crtc_arm_vblank_event(crtc, event);
390 		else
391 			drm_crtc_send_vblank_event(crtc, event);
392 		spin_unlock_irq(&crtc->dev->event_lock);
393 	}
394 }
395 
396 static int pl111_display_enable_vblank(struct drm_simple_display_pipe *pipe)
397 {
398 	struct drm_crtc *crtc = &pipe->crtc;
399 	struct drm_device *drm = crtc->dev;
400 	struct pl111_drm_dev_private *priv = drm->dev_private;
401 
402 	writel(CLCD_IRQ_NEXTBASE_UPDATE, priv->regs + priv->ienb);
403 
404 	return 0;
405 }
406 
407 static void pl111_display_disable_vblank(struct drm_simple_display_pipe *pipe)
408 {
409 	struct drm_crtc *crtc = &pipe->crtc;
410 	struct drm_device *drm = crtc->dev;
411 	struct pl111_drm_dev_private *priv = drm->dev_private;
412 
413 	writel(0, priv->regs + priv->ienb);
414 }
415 
416 static struct drm_simple_display_pipe_funcs pl111_display_funcs = {
417 	.mode_valid = pl111_mode_valid,
418 	.check = pl111_display_check,
419 	.enable = pl111_display_enable,
420 	.disable = pl111_display_disable,
421 	.update = pl111_display_update,
422 	.prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
423 };
424 
425 static int pl111_clk_div_choose_div(struct clk_hw *hw, unsigned long rate,
426 				    unsigned long *prate, bool set_parent)
427 {
428 	int best_div = 1, div;
429 	struct clk_hw *parent = clk_hw_get_parent(hw);
430 	unsigned long best_prate = 0;
431 	unsigned long best_diff = ~0ul;
432 	int max_div = (1 << (TIM2_PCD_LO_BITS + TIM2_PCD_HI_BITS)) - 1;
433 
434 	for (div = 1; div < max_div; div++) {
435 		unsigned long this_prate, div_rate, diff;
436 
437 		if (set_parent)
438 			this_prate = clk_hw_round_rate(parent, rate * div);
439 		else
440 			this_prate = *prate;
441 		div_rate = DIV_ROUND_UP_ULL(this_prate, div);
442 		diff = abs(rate - div_rate);
443 
444 		if (diff < best_diff) {
445 			best_div = div;
446 			best_diff = diff;
447 			best_prate = this_prate;
448 		}
449 	}
450 
451 	*prate = best_prate;
452 	return best_div;
453 }
454 
455 static long pl111_clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
456 				     unsigned long *prate)
457 {
458 	int div = pl111_clk_div_choose_div(hw, rate, prate, true);
459 
460 	return DIV_ROUND_UP_ULL(*prate, div);
461 }
462 
463 static unsigned long pl111_clk_div_recalc_rate(struct clk_hw *hw,
464 					       unsigned long prate)
465 {
466 	struct pl111_drm_dev_private *priv =
467 		container_of(hw, struct pl111_drm_dev_private, clk_div);
468 	u32 tim2 = readl(priv->regs + CLCD_TIM2);
469 	int div;
470 
471 	if (tim2 & TIM2_BCD)
472 		return prate;
473 
474 	div = tim2 & TIM2_PCD_LO_MASK;
475 	div |= (tim2 & TIM2_PCD_HI_MASK) >>
476 		(TIM2_PCD_HI_SHIFT - TIM2_PCD_LO_BITS);
477 	div += 2;
478 
479 	return DIV_ROUND_UP_ULL(prate, div);
480 }
481 
482 static int pl111_clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
483 				  unsigned long prate)
484 {
485 	struct pl111_drm_dev_private *priv =
486 		container_of(hw, struct pl111_drm_dev_private, clk_div);
487 	int div = pl111_clk_div_choose_div(hw, rate, &prate, false);
488 	u32 tim2;
489 
490 	spin_lock(&priv->tim2_lock);
491 	tim2 = readl(priv->regs + CLCD_TIM2);
492 	tim2 &= ~(TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
493 
494 	if (div == 1) {
495 		tim2 |= TIM2_BCD;
496 	} else {
497 		div -= 2;
498 		tim2 |= div & TIM2_PCD_LO_MASK;
499 		tim2 |= (div >> TIM2_PCD_LO_BITS) << TIM2_PCD_HI_SHIFT;
500 	}
501 
502 	writel(tim2, priv->regs + CLCD_TIM2);
503 	spin_unlock(&priv->tim2_lock);
504 
505 	return 0;
506 }
507 
508 static const struct clk_ops pl111_clk_div_ops = {
509 	.recalc_rate = pl111_clk_div_recalc_rate,
510 	.round_rate = pl111_clk_div_round_rate,
511 	.set_rate = pl111_clk_div_set_rate,
512 };
513 
514 static int
515 pl111_init_clock_divider(struct drm_device *drm)
516 {
517 	struct pl111_drm_dev_private *priv = drm->dev_private;
518 	struct clk *parent = devm_clk_get(drm->dev, "clcdclk");
519 	struct clk_hw *div = &priv->clk_div;
520 	const char *parent_name;
521 	struct clk_init_data init = {
522 		.name = "pl111_div",
523 		.ops = &pl111_clk_div_ops,
524 		.parent_names = &parent_name,
525 		.num_parents = 1,
526 		.flags = CLK_SET_RATE_PARENT,
527 	};
528 	int ret;
529 
530 	if (IS_ERR(parent)) {
531 		dev_err(drm->dev, "CLCD: unable to get clcdclk.\n");
532 		return PTR_ERR(parent);
533 	}
534 	/* If the clock divider is broken, use the parent directly */
535 	if (priv->variant->broken_clockdivider) {
536 		priv->clk = parent;
537 		return 0;
538 	}
539 	parent_name = __clk_get_name(parent);
540 
541 	spin_lock_init(&priv->tim2_lock);
542 	div->init = &init;
543 
544 	ret = devm_clk_hw_register(drm->dev, div);
545 
546 	priv->clk = div->clk;
547 	return ret;
548 }
549 
550 int pl111_display_init(struct drm_device *drm)
551 {
552 	struct pl111_drm_dev_private *priv = drm->dev_private;
553 	struct device *dev = drm->dev;
554 	struct device_node *endpoint;
555 	u32 tft_r0b0g0[3];
556 	int ret;
557 
558 	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
559 	if (!endpoint)
560 		return -ENODEV;
561 
562 	if (of_property_read_u32_array(endpoint,
563 				       "arm,pl11x,tft-r0g0b0-pads",
564 				       tft_r0b0g0,
565 				       ARRAY_SIZE(tft_r0b0g0)) != 0) {
566 		dev_err(dev, "arm,pl11x,tft-r0g0b0-pads should be 3 ints\n");
567 		of_node_put(endpoint);
568 		return -ENOENT;
569 	}
570 	of_node_put(endpoint);
571 
572 	ret = pl111_init_clock_divider(drm);
573 	if (ret)
574 		return ret;
575 
576 	if (!priv->variant->broken_vblank) {
577 		pl111_display_funcs.enable_vblank = pl111_display_enable_vblank;
578 		pl111_display_funcs.disable_vblank = pl111_display_disable_vblank;
579 	}
580 
581 	ret = drm_simple_display_pipe_init(drm, &priv->pipe,
582 					   &pl111_display_funcs,
583 					   priv->variant->formats,
584 					   priv->variant->nformats,
585 					   NULL,
586 					   priv->connector);
587 	if (ret)
588 		return ret;
589 
590 	return 0;
591 }
592