1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * (C) COPYRIGHT 2012-2013 ARM Limited. All rights reserved.
4  *
5  * Parts of this file were based on sources as follows:
6  *
7  * Copyright (c) 2006-2008 Intel Corporation
8  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
9  * Copyright (C) 2011 Texas Instruments
10  */
11 
12 #include <linux/amba/clcd-regs.h>
13 #include <linux/clk.h>
14 #include <linux/version.h>
15 #include <linux/dma-buf.h>
16 #include <linux/of_graph.h>
17 
18 #include <drm/drmP.h>
19 #include <drm/drm_gem_cma_helper.h>
20 #include <drm/drm_gem_framebuffer_helper.h>
21 #include <drm/drm_fb_cma_helper.h>
22 
23 #include "pl111_drm.h"
24 
25 irqreturn_t pl111_irq(int irq, void *data)
26 {
27 	struct pl111_drm_dev_private *priv = data;
28 	u32 irq_stat;
29 	irqreturn_t status = IRQ_NONE;
30 
31 	irq_stat = readl(priv->regs + CLCD_PL111_MIS);
32 
33 	if (!irq_stat)
34 		return IRQ_NONE;
35 
36 	if (irq_stat & CLCD_IRQ_NEXTBASE_UPDATE) {
37 		drm_crtc_handle_vblank(&priv->pipe.crtc);
38 
39 		status = IRQ_HANDLED;
40 	}
41 
42 	/* Clear the interrupt once done */
43 	writel(irq_stat, priv->regs + CLCD_PL111_ICR);
44 
45 	return status;
46 }
47 
48 static enum drm_mode_status
49 pl111_mode_valid(struct drm_crtc *crtc,
50 		 const struct drm_display_mode *mode)
51 {
52 	struct drm_device *drm = crtc->dev;
53 	struct pl111_drm_dev_private *priv = drm->dev_private;
54 	u32 cpp = priv->variant->fb_bpp / 8;
55 	u64 bw;
56 
57 	/*
58 	 * We use the pixelclock to also account for interlaced modes, the
59 	 * resulting bandwidth is in bytes per second.
60 	 */
61 	bw = mode->clock * 1000ULL; /* In Hz */
62 	bw = bw * mode->hdisplay * mode->vdisplay * cpp;
63 	bw = div_u64(bw, mode->htotal * mode->vtotal);
64 
65 	/*
66 	 * If no bandwidth constraints, anything goes, else
67 	 * check if we are too fast.
68 	 */
69 	if (priv->memory_bw && (bw > priv->memory_bw)) {
70 		DRM_DEBUG_KMS("%d x %d @ %d Hz, %d cpp, bw %llu too fast\n",
71 			      mode->hdisplay, mode->vdisplay,
72 			      mode->clock * 1000, cpp, bw);
73 
74 		return MODE_BAD;
75 	}
76 	DRM_DEBUG_KMS("%d x %d @ %d Hz, %d cpp, bw %llu bytes/s OK\n",
77 		      mode->hdisplay, mode->vdisplay,
78 		      mode->clock * 1000, cpp, bw);
79 
80 	return MODE_OK;
81 }
82 
83 static int pl111_display_check(struct drm_simple_display_pipe *pipe,
84 			       struct drm_plane_state *pstate,
85 			       struct drm_crtc_state *cstate)
86 {
87 	const struct drm_display_mode *mode = &cstate->mode;
88 	struct drm_framebuffer *old_fb = pipe->plane.state->fb;
89 	struct drm_framebuffer *fb = pstate->fb;
90 
91 	if (mode->hdisplay % 16)
92 		return -EINVAL;
93 
94 	if (fb) {
95 		u32 offset = drm_fb_cma_get_gem_addr(fb, pstate, 0);
96 
97 		/* FB base address must be dword aligned. */
98 		if (offset & 3)
99 			return -EINVAL;
100 
101 		/* There's no pitch register -- the mode's hdisplay
102 		 * controls it.
103 		 */
104 		if (fb->pitches[0] != mode->hdisplay * fb->format->cpp[0])
105 			return -EINVAL;
106 
107 		/* We can't change the FB format in a flicker-free
108 		 * manner (and only update it during CRTC enable).
109 		 */
110 		if (old_fb && old_fb->format != fb->format)
111 			cstate->mode_changed = true;
112 	}
113 
114 	return 0;
115 }
116 
117 static void pl111_display_enable(struct drm_simple_display_pipe *pipe,
118 				 struct drm_crtc_state *cstate,
119 				 struct drm_plane_state *plane_state)
120 {
121 	struct drm_crtc *crtc = &pipe->crtc;
122 	struct drm_plane *plane = &pipe->plane;
123 	struct drm_device *drm = crtc->dev;
124 	struct pl111_drm_dev_private *priv = drm->dev_private;
125 	const struct drm_display_mode *mode = &cstate->mode;
126 	struct drm_framebuffer *fb = plane->state->fb;
127 	struct drm_connector *connector = priv->connector;
128 	struct drm_bridge *bridge = priv->bridge;
129 	u32 cntl;
130 	u32 ppl, hsw, hfp, hbp;
131 	u32 lpp, vsw, vfp, vbp;
132 	u32 cpl, tim2;
133 	int ret;
134 
135 	ret = clk_set_rate(priv->clk, mode->clock * 1000);
136 	if (ret) {
137 		dev_err(drm->dev,
138 			"Failed to set pixel clock rate to %d: %d\n",
139 			mode->clock * 1000, ret);
140 	}
141 
142 	clk_prepare_enable(priv->clk);
143 
144 	ppl = (mode->hdisplay / 16) - 1;
145 	hsw = mode->hsync_end - mode->hsync_start - 1;
146 	hfp = mode->hsync_start - mode->hdisplay - 1;
147 	hbp = mode->htotal - mode->hsync_end - 1;
148 
149 	lpp = mode->vdisplay - 1;
150 	vsw = mode->vsync_end - mode->vsync_start - 1;
151 	vfp = mode->vsync_start - mode->vdisplay;
152 	vbp = mode->vtotal - mode->vsync_end;
153 
154 	cpl = mode->hdisplay - 1;
155 
156 	writel((ppl << 2) |
157 	       (hsw << 8) |
158 	       (hfp << 16) |
159 	       (hbp << 24),
160 	       priv->regs + CLCD_TIM0);
161 	writel(lpp |
162 	       (vsw << 10) |
163 	       (vfp << 16) |
164 	       (vbp << 24),
165 	       priv->regs + CLCD_TIM1);
166 
167 	spin_lock(&priv->tim2_lock);
168 
169 	tim2 = readl(priv->regs + CLCD_TIM2);
170 	tim2 &= (TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
171 
172 	if (priv->variant->broken_clockdivider)
173 		tim2 |= TIM2_BCD;
174 
175 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
176 		tim2 |= TIM2_IHS;
177 
178 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
179 		tim2 |= TIM2_IVS;
180 
181 	if (connector) {
182 		if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
183 			tim2 |= TIM2_IOE;
184 
185 		if (connector->display_info.bus_flags &
186 		    DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
187 			tim2 |= TIM2_IPC;
188 	}
189 
190 	if (bridge) {
191 		const struct drm_bridge_timings *btimings = bridge->timings;
192 
193 		/*
194 		 * Here is when things get really fun. Sometimes the bridge
195 		 * timings are such that the signal out from PL11x is not
196 		 * stable before the receiving bridge (such as a dumb VGA DAC
197 		 * or similar) samples it. If that happens, we compensate by
198 		 * the only method we have: output the data on the opposite
199 		 * edge of the clock so it is for sure stable when it gets
200 		 * sampled.
201 		 *
202 		 * The PL111 manual does not contain proper timining diagrams
203 		 * or data for these details, but we know from experiments
204 		 * that the setup time is more than 3000 picoseconds (3 ns).
205 		 * If we have a bridge that requires the signal to be stable
206 		 * earlier than 3000 ps before the clock pulse, we have to
207 		 * output the data on the opposite edge to avoid flicker.
208 		 */
209 		if (btimings && btimings->setup_time_ps >= 3000)
210 			tim2 ^= TIM2_IPC;
211 	}
212 
213 	tim2 |= cpl << 16;
214 	writel(tim2, priv->regs + CLCD_TIM2);
215 	spin_unlock(&priv->tim2_lock);
216 
217 	writel(0, priv->regs + CLCD_TIM3);
218 
219 	/* Hard-code TFT panel */
220 	cntl = CNTL_LCDEN | CNTL_LCDTFT | CNTL_LCDVCOMP(1);
221 	/* On the ST Micro variant, assume all 24 bits are connected */
222 	if (priv->variant->st_bitmux_control)
223 		cntl |= CNTL_ST_CDWID_24;
224 
225 	/*
226 	 * Note that the the ARM hardware's format reader takes 'r' from
227 	 * the low bit, while DRM formats list channels from high bit
228 	 * to low bit as you read left to right. The ST Micro version of
229 	 * the PL110 (LCDC) however uses the standard DRM format.
230 	 */
231 	switch (fb->format->format) {
232 	case DRM_FORMAT_BGR888:
233 		/* Only supported on the ST Micro variant */
234 		if (priv->variant->st_bitmux_control)
235 			cntl |= CNTL_ST_LCDBPP24_PACKED | CNTL_BGR;
236 		break;
237 	case DRM_FORMAT_RGB888:
238 		/* Only supported on the ST Micro variant */
239 		if (priv->variant->st_bitmux_control)
240 			cntl |= CNTL_ST_LCDBPP24_PACKED;
241 		break;
242 	case DRM_FORMAT_ABGR8888:
243 	case DRM_FORMAT_XBGR8888:
244 		if (priv->variant->st_bitmux_control)
245 			cntl |= CNTL_LCDBPP24 | CNTL_BGR;
246 		else
247 			cntl |= CNTL_LCDBPP24;
248 		break;
249 	case DRM_FORMAT_ARGB8888:
250 	case DRM_FORMAT_XRGB8888:
251 		if (priv->variant->st_bitmux_control)
252 			cntl |= CNTL_LCDBPP24;
253 		else
254 			cntl |= CNTL_LCDBPP24 | CNTL_BGR;
255 		break;
256 	case DRM_FORMAT_BGR565:
257 		if (priv->variant->is_pl110)
258 			cntl |= CNTL_LCDBPP16;
259 		else if (priv->variant->st_bitmux_control)
260 			cntl |= CNTL_LCDBPP16 | CNTL_ST_1XBPP_565 | CNTL_BGR;
261 		else
262 			cntl |= CNTL_LCDBPP16_565;
263 		break;
264 	case DRM_FORMAT_RGB565:
265 		if (priv->variant->is_pl110)
266 			cntl |= CNTL_LCDBPP16 | CNTL_BGR;
267 		else if (priv->variant->st_bitmux_control)
268 			cntl |= CNTL_LCDBPP16 | CNTL_ST_1XBPP_565;
269 		else
270 			cntl |= CNTL_LCDBPP16_565 | CNTL_BGR;
271 		break;
272 	case DRM_FORMAT_ABGR1555:
273 	case DRM_FORMAT_XBGR1555:
274 		cntl |= CNTL_LCDBPP16;
275 		if (priv->variant->st_bitmux_control)
276 			cntl |= CNTL_ST_1XBPP_5551 | CNTL_BGR;
277 		break;
278 	case DRM_FORMAT_ARGB1555:
279 	case DRM_FORMAT_XRGB1555:
280 		cntl |= CNTL_LCDBPP16;
281 		if (priv->variant->st_bitmux_control)
282 			cntl |= CNTL_ST_1XBPP_5551;
283 		else
284 			cntl |= CNTL_BGR;
285 		break;
286 	case DRM_FORMAT_ABGR4444:
287 	case DRM_FORMAT_XBGR4444:
288 		cntl |= CNTL_LCDBPP16_444;
289 		if (priv->variant->st_bitmux_control)
290 			cntl |= CNTL_ST_1XBPP_444 | CNTL_BGR;
291 		break;
292 	case DRM_FORMAT_ARGB4444:
293 	case DRM_FORMAT_XRGB4444:
294 		cntl |= CNTL_LCDBPP16_444;
295 		if (priv->variant->st_bitmux_control)
296 			cntl |= CNTL_ST_1XBPP_444;
297 		else
298 			cntl |= CNTL_BGR;
299 		break;
300 	default:
301 		WARN_ONCE(true, "Unknown FB format 0x%08x\n",
302 			  fb->format->format);
303 		break;
304 	}
305 
306 	/* The PL110 in Integrator/Versatile does the BGR routing externally */
307 	if (priv->variant->external_bgr)
308 		cntl &= ~CNTL_BGR;
309 
310 	/* Power sequence: first enable and chill */
311 	writel(cntl, priv->regs + priv->ctrl);
312 
313 	/*
314 	 * We expect this delay to stabilize the contrast
315 	 * voltage Vee as stipulated by the manual
316 	 */
317 	msleep(20);
318 
319 	if (priv->variant_display_enable)
320 		priv->variant_display_enable(drm, fb->format->format);
321 
322 	/* Power Up */
323 	cntl |= CNTL_LCDPWR;
324 	writel(cntl, priv->regs + priv->ctrl);
325 
326 	if (!priv->variant->broken_vblank)
327 		drm_crtc_vblank_on(crtc);
328 }
329 
330 void pl111_display_disable(struct drm_simple_display_pipe *pipe)
331 {
332 	struct drm_crtc *crtc = &pipe->crtc;
333 	struct drm_device *drm = crtc->dev;
334 	struct pl111_drm_dev_private *priv = drm->dev_private;
335 	u32 cntl;
336 
337 	if (!priv->variant->broken_vblank)
338 		drm_crtc_vblank_off(crtc);
339 
340 	/* Power Down */
341 	cntl = readl(priv->regs + priv->ctrl);
342 	if (cntl & CNTL_LCDPWR) {
343 		cntl &= ~CNTL_LCDPWR;
344 		writel(cntl, priv->regs + priv->ctrl);
345 	}
346 
347 	/*
348 	 * We expect this delay to stabilize the contrast voltage Vee as
349 	 * stipulated by the manual
350 	 */
351 	msleep(20);
352 
353 	if (priv->variant_display_disable)
354 		priv->variant_display_disable(drm);
355 
356 	/* Disable */
357 	writel(0, priv->regs + priv->ctrl);
358 
359 	clk_disable_unprepare(priv->clk);
360 }
361 
362 static void pl111_display_update(struct drm_simple_display_pipe *pipe,
363 				 struct drm_plane_state *old_pstate)
364 {
365 	struct drm_crtc *crtc = &pipe->crtc;
366 	struct drm_device *drm = crtc->dev;
367 	struct pl111_drm_dev_private *priv = drm->dev_private;
368 	struct drm_pending_vblank_event *event = crtc->state->event;
369 	struct drm_plane *plane = &pipe->plane;
370 	struct drm_plane_state *pstate = plane->state;
371 	struct drm_framebuffer *fb = pstate->fb;
372 
373 	if (fb) {
374 		u32 addr = drm_fb_cma_get_gem_addr(fb, pstate, 0);
375 
376 		writel(addr, priv->regs + CLCD_UBAS);
377 	}
378 
379 	if (event) {
380 		crtc->state->event = NULL;
381 
382 		spin_lock_irq(&crtc->dev->event_lock);
383 		if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
384 			drm_crtc_arm_vblank_event(crtc, event);
385 		else
386 			drm_crtc_send_vblank_event(crtc, event);
387 		spin_unlock_irq(&crtc->dev->event_lock);
388 	}
389 }
390 
391 static int pl111_display_enable_vblank(struct drm_simple_display_pipe *pipe)
392 {
393 	struct drm_crtc *crtc = &pipe->crtc;
394 	struct drm_device *drm = crtc->dev;
395 	struct pl111_drm_dev_private *priv = drm->dev_private;
396 
397 	writel(CLCD_IRQ_NEXTBASE_UPDATE, priv->regs + priv->ienb);
398 
399 	return 0;
400 }
401 
402 static void pl111_display_disable_vblank(struct drm_simple_display_pipe *pipe)
403 {
404 	struct drm_crtc *crtc = &pipe->crtc;
405 	struct drm_device *drm = crtc->dev;
406 	struct pl111_drm_dev_private *priv = drm->dev_private;
407 
408 	writel(0, priv->regs + priv->ienb);
409 }
410 
411 static struct drm_simple_display_pipe_funcs pl111_display_funcs = {
412 	.mode_valid = pl111_mode_valid,
413 	.check = pl111_display_check,
414 	.enable = pl111_display_enable,
415 	.disable = pl111_display_disable,
416 	.update = pl111_display_update,
417 	.prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
418 };
419 
420 static int pl111_clk_div_choose_div(struct clk_hw *hw, unsigned long rate,
421 				    unsigned long *prate, bool set_parent)
422 {
423 	int best_div = 1, div;
424 	struct clk_hw *parent = clk_hw_get_parent(hw);
425 	unsigned long best_prate = 0;
426 	unsigned long best_diff = ~0ul;
427 	int max_div = (1 << (TIM2_PCD_LO_BITS + TIM2_PCD_HI_BITS)) - 1;
428 
429 	for (div = 1; div < max_div; div++) {
430 		unsigned long this_prate, div_rate, diff;
431 
432 		if (set_parent)
433 			this_prate = clk_hw_round_rate(parent, rate * div);
434 		else
435 			this_prate = *prate;
436 		div_rate = DIV_ROUND_UP_ULL(this_prate, div);
437 		diff = abs(rate - div_rate);
438 
439 		if (diff < best_diff) {
440 			best_div = div;
441 			best_diff = diff;
442 			best_prate = this_prate;
443 		}
444 	}
445 
446 	*prate = best_prate;
447 	return best_div;
448 }
449 
450 static long pl111_clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
451 				     unsigned long *prate)
452 {
453 	int div = pl111_clk_div_choose_div(hw, rate, prate, true);
454 
455 	return DIV_ROUND_UP_ULL(*prate, div);
456 }
457 
458 static unsigned long pl111_clk_div_recalc_rate(struct clk_hw *hw,
459 					       unsigned long prate)
460 {
461 	struct pl111_drm_dev_private *priv =
462 		container_of(hw, struct pl111_drm_dev_private, clk_div);
463 	u32 tim2 = readl(priv->regs + CLCD_TIM2);
464 	int div;
465 
466 	if (tim2 & TIM2_BCD)
467 		return prate;
468 
469 	div = tim2 & TIM2_PCD_LO_MASK;
470 	div |= (tim2 & TIM2_PCD_HI_MASK) >>
471 		(TIM2_PCD_HI_SHIFT - TIM2_PCD_LO_BITS);
472 	div += 2;
473 
474 	return DIV_ROUND_UP_ULL(prate, div);
475 }
476 
477 static int pl111_clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
478 				  unsigned long prate)
479 {
480 	struct pl111_drm_dev_private *priv =
481 		container_of(hw, struct pl111_drm_dev_private, clk_div);
482 	int div = pl111_clk_div_choose_div(hw, rate, &prate, false);
483 	u32 tim2;
484 
485 	spin_lock(&priv->tim2_lock);
486 	tim2 = readl(priv->regs + CLCD_TIM2);
487 	tim2 &= ~(TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
488 
489 	if (div == 1) {
490 		tim2 |= TIM2_BCD;
491 	} else {
492 		div -= 2;
493 		tim2 |= div & TIM2_PCD_LO_MASK;
494 		tim2 |= (div >> TIM2_PCD_LO_BITS) << TIM2_PCD_HI_SHIFT;
495 	}
496 
497 	writel(tim2, priv->regs + CLCD_TIM2);
498 	spin_unlock(&priv->tim2_lock);
499 
500 	return 0;
501 }
502 
503 static const struct clk_ops pl111_clk_div_ops = {
504 	.recalc_rate = pl111_clk_div_recalc_rate,
505 	.round_rate = pl111_clk_div_round_rate,
506 	.set_rate = pl111_clk_div_set_rate,
507 };
508 
509 static int
510 pl111_init_clock_divider(struct drm_device *drm)
511 {
512 	struct pl111_drm_dev_private *priv = drm->dev_private;
513 	struct clk *parent = devm_clk_get(drm->dev, "clcdclk");
514 	struct clk_hw *div = &priv->clk_div;
515 	const char *parent_name;
516 	struct clk_init_data init = {
517 		.name = "pl111_div",
518 		.ops = &pl111_clk_div_ops,
519 		.parent_names = &parent_name,
520 		.num_parents = 1,
521 		.flags = CLK_SET_RATE_PARENT,
522 	};
523 	int ret;
524 
525 	if (IS_ERR(parent)) {
526 		dev_err(drm->dev, "CLCD: unable to get clcdclk.\n");
527 		return PTR_ERR(parent);
528 	}
529 
530 	spin_lock_init(&priv->tim2_lock);
531 
532 	/* If the clock divider is broken, use the parent directly */
533 	if (priv->variant->broken_clockdivider) {
534 		priv->clk = parent;
535 		return 0;
536 	}
537 	parent_name = __clk_get_name(parent);
538 	div->init = &init;
539 
540 	ret = devm_clk_hw_register(drm->dev, div);
541 
542 	priv->clk = div->clk;
543 	return ret;
544 }
545 
546 int pl111_display_init(struct drm_device *drm)
547 {
548 	struct pl111_drm_dev_private *priv = drm->dev_private;
549 	struct device *dev = drm->dev;
550 	struct device_node *endpoint;
551 	u32 tft_r0b0g0[3];
552 	int ret;
553 
554 	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
555 	if (!endpoint)
556 		return -ENODEV;
557 
558 	if (of_property_read_u32_array(endpoint,
559 				       "arm,pl11x,tft-r0g0b0-pads",
560 				       tft_r0b0g0,
561 				       ARRAY_SIZE(tft_r0b0g0)) != 0) {
562 		dev_err(dev, "arm,pl11x,tft-r0g0b0-pads should be 3 ints\n");
563 		of_node_put(endpoint);
564 		return -ENOENT;
565 	}
566 	of_node_put(endpoint);
567 
568 	ret = pl111_init_clock_divider(drm);
569 	if (ret)
570 		return ret;
571 
572 	if (!priv->variant->broken_vblank) {
573 		pl111_display_funcs.enable_vblank = pl111_display_enable_vblank;
574 		pl111_display_funcs.disable_vblank = pl111_display_disable_vblank;
575 	}
576 
577 	ret = drm_simple_display_pipe_init(drm, &priv->pipe,
578 					   &pl111_display_funcs,
579 					   priv->variant->formats,
580 					   priv->variant->nformats,
581 					   NULL,
582 					   priv->connector);
583 	if (ret)
584 		return ret;
585 
586 	return 0;
587 }
588