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 int pl111_display_check(struct drm_simple_display_pipe *pipe,
54 			       struct drm_plane_state *pstate,
55 			       struct drm_crtc_state *cstate)
56 {
57 	const struct drm_display_mode *mode = &cstate->mode;
58 	struct drm_framebuffer *old_fb = pipe->plane.state->fb;
59 	struct drm_framebuffer *fb = pstate->fb;
60 
61 	if (mode->hdisplay % 16)
62 		return -EINVAL;
63 
64 	if (fb) {
65 		u32 offset = drm_fb_cma_get_gem_addr(fb, pstate, 0);
66 
67 		/* FB base address must be dword aligned. */
68 		if (offset & 3)
69 			return -EINVAL;
70 
71 		/* There's no pitch register -- the mode's hdisplay
72 		 * controls it.
73 		 */
74 		if (fb->pitches[0] != mode->hdisplay * fb->format->cpp[0])
75 			return -EINVAL;
76 
77 		/* We can't change the FB format in a flicker-free
78 		 * manner (and only update it during CRTC enable).
79 		 */
80 		if (old_fb && old_fb->format != fb->format)
81 			cstate->mode_changed = true;
82 	}
83 
84 	return 0;
85 }
86 
87 static void pl111_display_enable(struct drm_simple_display_pipe *pipe,
88 				 struct drm_crtc_state *cstate)
89 {
90 	struct drm_crtc *crtc = &pipe->crtc;
91 	struct drm_plane *plane = &pipe->plane;
92 	struct drm_device *drm = crtc->dev;
93 	struct pl111_drm_dev_private *priv = drm->dev_private;
94 	const struct drm_display_mode *mode = &cstate->mode;
95 	struct drm_framebuffer *fb = plane->state->fb;
96 	struct drm_connector *connector = priv->connector;
97 	struct drm_bridge *bridge = priv->bridge;
98 	u32 cntl;
99 	u32 ppl, hsw, hfp, hbp;
100 	u32 lpp, vsw, vfp, vbp;
101 	u32 cpl, tim2;
102 	int ret;
103 
104 	ret = clk_set_rate(priv->clk, mode->clock * 1000);
105 	if (ret) {
106 		dev_err(drm->dev,
107 			"Failed to set pixel clock rate to %d: %d\n",
108 			mode->clock * 1000, ret);
109 	}
110 
111 	clk_prepare_enable(priv->clk);
112 
113 	ppl = (mode->hdisplay / 16) - 1;
114 	hsw = mode->hsync_end - mode->hsync_start - 1;
115 	hfp = mode->hsync_start - mode->hdisplay - 1;
116 	hbp = mode->htotal - mode->hsync_end - 1;
117 
118 	lpp = mode->vdisplay - 1;
119 	vsw = mode->vsync_end - mode->vsync_start - 1;
120 	vfp = mode->vsync_start - mode->vdisplay;
121 	vbp = mode->vtotal - mode->vsync_end;
122 
123 	cpl = mode->hdisplay - 1;
124 
125 	writel((ppl << 2) |
126 	       (hsw << 8) |
127 	       (hfp << 16) |
128 	       (hbp << 24),
129 	       priv->regs + CLCD_TIM0);
130 	writel(lpp |
131 	       (vsw << 10) |
132 	       (vfp << 16) |
133 	       (vbp << 24),
134 	       priv->regs + CLCD_TIM1);
135 
136 	spin_lock(&priv->tim2_lock);
137 
138 	tim2 = readl(priv->regs + CLCD_TIM2);
139 	tim2 &= (TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
140 
141 	if (priv->variant->broken_clockdivider)
142 		tim2 |= TIM2_BCD;
143 
144 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
145 		tim2 |= TIM2_IHS;
146 
147 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
148 		tim2 |= TIM2_IVS;
149 
150 	if (connector) {
151 		if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
152 			tim2 |= TIM2_IOE;
153 
154 		if (connector->display_info.bus_flags &
155 		    DRM_BUS_FLAG_PIXDATA_NEGEDGE)
156 			tim2 |= TIM2_IPC;
157 	}
158 
159 	if (bridge) {
160 		const struct drm_bridge_timings *btimings = bridge->timings;
161 
162 		/*
163 		 * Here is when things get really fun. Sometimes the bridge
164 		 * timings are such that the signal out from PL11x is not
165 		 * stable before the receiving bridge (such as a dumb VGA DAC
166 		 * or similar) samples it. If that happens, we compensate by
167 		 * the only method we have: output the data on the opposite
168 		 * edge of the clock so it is for sure stable when it gets
169 		 * sampled.
170 		 *
171 		 * The PL111 manual does not contain proper timining diagrams
172 		 * or data for these details, but we know from experiments
173 		 * that the setup time is more than 3000 picoseconds (3 ns).
174 		 * If we have a bridge that requires the signal to be stable
175 		 * earlier than 3000 ps before the clock pulse, we have to
176 		 * output the data on the opposite edge to avoid flicker.
177 		 */
178 		if (btimings && btimings->setup_time_ps >= 3000)
179 			tim2 ^= TIM2_IPC;
180 	}
181 
182 	tim2 |= cpl << 16;
183 	writel(tim2, priv->regs + CLCD_TIM2);
184 	spin_unlock(&priv->tim2_lock);
185 
186 	writel(0, priv->regs + CLCD_TIM3);
187 
188 	/* Hard-code TFT panel */
189 	cntl = CNTL_LCDEN | CNTL_LCDTFT | CNTL_LCDVCOMP(1);
190 
191 	/* Note that the the hardware's format reader takes 'r' from
192 	 * the low bit, while DRM formats list channels from high bit
193 	 * to low bit as you read left to right.
194 	 */
195 	switch (fb->format->format) {
196 	case DRM_FORMAT_ABGR8888:
197 	case DRM_FORMAT_XBGR8888:
198 		cntl |= CNTL_LCDBPP24;
199 		break;
200 	case DRM_FORMAT_ARGB8888:
201 	case DRM_FORMAT_XRGB8888:
202 		cntl |= CNTL_LCDBPP24 | CNTL_BGR;
203 		break;
204 	case DRM_FORMAT_BGR565:
205 		if (priv->variant->is_pl110)
206 			cntl |= CNTL_LCDBPP16;
207 		else
208 			cntl |= CNTL_LCDBPP16_565;
209 		break;
210 	case DRM_FORMAT_RGB565:
211 		if (priv->variant->is_pl110)
212 			cntl |= CNTL_LCDBPP16;
213 		else
214 			cntl |= CNTL_LCDBPP16_565;
215 		cntl |= CNTL_BGR;
216 		break;
217 	case DRM_FORMAT_ABGR1555:
218 	case DRM_FORMAT_XBGR1555:
219 		cntl |= CNTL_LCDBPP16;
220 		break;
221 	case DRM_FORMAT_ARGB1555:
222 	case DRM_FORMAT_XRGB1555:
223 		cntl |= CNTL_LCDBPP16 | CNTL_BGR;
224 		break;
225 	case DRM_FORMAT_ABGR4444:
226 	case DRM_FORMAT_XBGR4444:
227 		cntl |= CNTL_LCDBPP16_444;
228 		break;
229 	case DRM_FORMAT_ARGB4444:
230 	case DRM_FORMAT_XRGB4444:
231 		cntl |= CNTL_LCDBPP16_444 | CNTL_BGR;
232 		break;
233 	default:
234 		WARN_ONCE(true, "Unknown FB format 0x%08x\n",
235 			  fb->format->format);
236 		break;
237 	}
238 
239 	/* The PL110 in Integrator/Versatile does the BGR routing externally */
240 	if (priv->variant->external_bgr)
241 		cntl &= ~CNTL_BGR;
242 
243 	/* Power sequence: first enable and chill */
244 	writel(cntl, priv->regs + priv->ctrl);
245 
246 	/*
247 	 * We expect this delay to stabilize the contrast
248 	 * voltage Vee as stipulated by the manual
249 	 */
250 	msleep(20);
251 
252 	if (priv->variant_display_enable)
253 		priv->variant_display_enable(drm, fb->format->format);
254 
255 	/* Power Up */
256 	cntl |= CNTL_LCDPWR;
257 	writel(cntl, priv->regs + priv->ctrl);
258 
259 	if (!priv->variant->broken_vblank)
260 		drm_crtc_vblank_on(crtc);
261 }
262 
263 void pl111_display_disable(struct drm_simple_display_pipe *pipe)
264 {
265 	struct drm_crtc *crtc = &pipe->crtc;
266 	struct drm_device *drm = crtc->dev;
267 	struct pl111_drm_dev_private *priv = drm->dev_private;
268 	u32 cntl;
269 
270 	if (!priv->variant->broken_vblank)
271 		drm_crtc_vblank_off(crtc);
272 
273 	/* Power Down */
274 	cntl = readl(priv->regs + priv->ctrl);
275 	if (cntl & CNTL_LCDPWR) {
276 		cntl &= ~CNTL_LCDPWR;
277 		writel(cntl, priv->regs + priv->ctrl);
278 	}
279 
280 	/*
281 	 * We expect this delay to stabilize the contrast voltage Vee as
282 	 * stipulated by the manual
283 	 */
284 	msleep(20);
285 
286 	if (priv->variant_display_disable)
287 		priv->variant_display_disable(drm);
288 
289 	/* Disable */
290 	writel(0, priv->regs + priv->ctrl);
291 
292 	clk_disable_unprepare(priv->clk);
293 }
294 
295 static void pl111_display_update(struct drm_simple_display_pipe *pipe,
296 				 struct drm_plane_state *old_pstate)
297 {
298 	struct drm_crtc *crtc = &pipe->crtc;
299 	struct drm_device *drm = crtc->dev;
300 	struct pl111_drm_dev_private *priv = drm->dev_private;
301 	struct drm_pending_vblank_event *event = crtc->state->event;
302 	struct drm_plane *plane = &pipe->plane;
303 	struct drm_plane_state *pstate = plane->state;
304 	struct drm_framebuffer *fb = pstate->fb;
305 
306 	if (fb) {
307 		u32 addr = drm_fb_cma_get_gem_addr(fb, pstate, 0);
308 
309 		writel(addr, priv->regs + CLCD_UBAS);
310 	}
311 
312 	if (event) {
313 		crtc->state->event = NULL;
314 
315 		spin_lock_irq(&crtc->dev->event_lock);
316 		if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
317 			drm_crtc_arm_vblank_event(crtc, event);
318 		else
319 			drm_crtc_send_vblank_event(crtc, event);
320 		spin_unlock_irq(&crtc->dev->event_lock);
321 	}
322 }
323 
324 int pl111_enable_vblank(struct drm_device *drm, unsigned int crtc)
325 {
326 	struct pl111_drm_dev_private *priv = drm->dev_private;
327 
328 	writel(CLCD_IRQ_NEXTBASE_UPDATE, priv->regs + priv->ienb);
329 
330 	return 0;
331 }
332 
333 void pl111_disable_vblank(struct drm_device *drm, unsigned int crtc)
334 {
335 	struct pl111_drm_dev_private *priv = drm->dev_private;
336 
337 	writel(0, priv->regs + priv->ienb);
338 }
339 
340 static int pl111_display_prepare_fb(struct drm_simple_display_pipe *pipe,
341 				    struct drm_plane_state *plane_state)
342 {
343 	return drm_gem_fb_prepare_fb(&pipe->plane, plane_state);
344 }
345 
346 static const struct drm_simple_display_pipe_funcs pl111_display_funcs = {
347 	.check = pl111_display_check,
348 	.enable = pl111_display_enable,
349 	.disable = pl111_display_disable,
350 	.update = pl111_display_update,
351 	.prepare_fb = pl111_display_prepare_fb,
352 };
353 
354 static int pl111_clk_div_choose_div(struct clk_hw *hw, unsigned long rate,
355 				    unsigned long *prate, bool set_parent)
356 {
357 	int best_div = 1, div;
358 	struct clk_hw *parent = clk_hw_get_parent(hw);
359 	unsigned long best_prate = 0;
360 	unsigned long best_diff = ~0ul;
361 	int max_div = (1 << (TIM2_PCD_LO_BITS + TIM2_PCD_HI_BITS)) - 1;
362 
363 	for (div = 1; div < max_div; div++) {
364 		unsigned long this_prate, div_rate, diff;
365 
366 		if (set_parent)
367 			this_prate = clk_hw_round_rate(parent, rate * div);
368 		else
369 			this_prate = *prate;
370 		div_rate = DIV_ROUND_UP_ULL(this_prate, div);
371 		diff = abs(rate - div_rate);
372 
373 		if (diff < best_diff) {
374 			best_div = div;
375 			best_diff = diff;
376 			best_prate = this_prate;
377 		}
378 	}
379 
380 	*prate = best_prate;
381 	return best_div;
382 }
383 
384 static long pl111_clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
385 				     unsigned long *prate)
386 {
387 	int div = pl111_clk_div_choose_div(hw, rate, prate, true);
388 
389 	return DIV_ROUND_UP_ULL(*prate, div);
390 }
391 
392 static unsigned long pl111_clk_div_recalc_rate(struct clk_hw *hw,
393 					       unsigned long prate)
394 {
395 	struct pl111_drm_dev_private *priv =
396 		container_of(hw, struct pl111_drm_dev_private, clk_div);
397 	u32 tim2 = readl(priv->regs + CLCD_TIM2);
398 	int div;
399 
400 	if (tim2 & TIM2_BCD)
401 		return prate;
402 
403 	div = tim2 & TIM2_PCD_LO_MASK;
404 	div |= (tim2 & TIM2_PCD_HI_MASK) >>
405 		(TIM2_PCD_HI_SHIFT - TIM2_PCD_LO_BITS);
406 	div += 2;
407 
408 	return DIV_ROUND_UP_ULL(prate, div);
409 }
410 
411 static int pl111_clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
412 				  unsigned long prate)
413 {
414 	struct pl111_drm_dev_private *priv =
415 		container_of(hw, struct pl111_drm_dev_private, clk_div);
416 	int div = pl111_clk_div_choose_div(hw, rate, &prate, false);
417 	u32 tim2;
418 
419 	spin_lock(&priv->tim2_lock);
420 	tim2 = readl(priv->regs + CLCD_TIM2);
421 	tim2 &= ~(TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
422 
423 	if (div == 1) {
424 		tim2 |= TIM2_BCD;
425 	} else {
426 		div -= 2;
427 		tim2 |= div & TIM2_PCD_LO_MASK;
428 		tim2 |= (div >> TIM2_PCD_LO_BITS) << TIM2_PCD_HI_SHIFT;
429 	}
430 
431 	writel(tim2, priv->regs + CLCD_TIM2);
432 	spin_unlock(&priv->tim2_lock);
433 
434 	return 0;
435 }
436 
437 static const struct clk_ops pl111_clk_div_ops = {
438 	.recalc_rate = pl111_clk_div_recalc_rate,
439 	.round_rate = pl111_clk_div_round_rate,
440 	.set_rate = pl111_clk_div_set_rate,
441 };
442 
443 static int
444 pl111_init_clock_divider(struct drm_device *drm)
445 {
446 	struct pl111_drm_dev_private *priv = drm->dev_private;
447 	struct clk *parent = devm_clk_get(drm->dev, "clcdclk");
448 	struct clk_hw *div = &priv->clk_div;
449 	const char *parent_name;
450 	struct clk_init_data init = {
451 		.name = "pl111_div",
452 		.ops = &pl111_clk_div_ops,
453 		.parent_names = &parent_name,
454 		.num_parents = 1,
455 		.flags = CLK_SET_RATE_PARENT,
456 	};
457 	int ret;
458 
459 	if (IS_ERR(parent)) {
460 		dev_err(drm->dev, "CLCD: unable to get clcdclk.\n");
461 		return PTR_ERR(parent);
462 	}
463 	/* If the clock divider is broken, use the parent directly */
464 	if (priv->variant->broken_clockdivider) {
465 		priv->clk = parent;
466 		return 0;
467 	}
468 	parent_name = __clk_get_name(parent);
469 
470 	spin_lock_init(&priv->tim2_lock);
471 	div->init = &init;
472 
473 	ret = devm_clk_hw_register(drm->dev, div);
474 
475 	priv->clk = div->clk;
476 	return ret;
477 }
478 
479 int pl111_display_init(struct drm_device *drm)
480 {
481 	struct pl111_drm_dev_private *priv = drm->dev_private;
482 	struct device *dev = drm->dev;
483 	struct device_node *endpoint;
484 	u32 tft_r0b0g0[3];
485 	int ret;
486 
487 	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
488 	if (!endpoint)
489 		return -ENODEV;
490 
491 	if (of_property_read_u32_array(endpoint,
492 				       "arm,pl11x,tft-r0g0b0-pads",
493 				       tft_r0b0g0,
494 				       ARRAY_SIZE(tft_r0b0g0)) != 0) {
495 		dev_err(dev, "arm,pl11x,tft-r0g0b0-pads should be 3 ints\n");
496 		of_node_put(endpoint);
497 		return -ENOENT;
498 	}
499 	of_node_put(endpoint);
500 
501 	ret = pl111_init_clock_divider(drm);
502 	if (ret)
503 		return ret;
504 
505 	ret = drm_simple_display_pipe_init(drm, &priv->pipe,
506 					   &pl111_display_funcs,
507 					   priv->variant->formats,
508 					   priv->variant->nformats,
509 					   NULL,
510 					   priv->connector);
511 	if (ret)
512 		return ret;
513 
514 	return 0;
515 }
516