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 	u32 cntl;
98 	u32 ppl, hsw, hfp, hbp;
99 	u32 lpp, vsw, vfp, vbp;
100 	u32 cpl, tim2;
101 	int ret;
102 
103 	ret = clk_set_rate(priv->clk, mode->clock * 1000);
104 	if (ret) {
105 		dev_err(drm->dev,
106 			"Failed to set pixel clock rate to %d: %d\n",
107 			mode->clock * 1000, ret);
108 	}
109 
110 	clk_prepare_enable(priv->clk);
111 
112 	ppl = (mode->hdisplay / 16) - 1;
113 	hsw = mode->hsync_end - mode->hsync_start - 1;
114 	hfp = mode->hsync_start - mode->hdisplay - 1;
115 	hbp = mode->htotal - mode->hsync_end - 1;
116 
117 	lpp = mode->vdisplay - 1;
118 	vsw = mode->vsync_end - mode->vsync_start - 1;
119 	vfp = mode->vsync_start - mode->vdisplay;
120 	vbp = mode->vtotal - mode->vsync_end;
121 
122 	cpl = mode->hdisplay - 1;
123 
124 	writel((ppl << 2) |
125 	       (hsw << 8) |
126 	       (hfp << 16) |
127 	       (hbp << 24),
128 	       priv->regs + CLCD_TIM0);
129 	writel(lpp |
130 	       (vsw << 10) |
131 	       (vfp << 16) |
132 	       (vbp << 24),
133 	       priv->regs + CLCD_TIM1);
134 
135 	spin_lock(&priv->tim2_lock);
136 
137 	tim2 = readl(priv->regs + CLCD_TIM2);
138 	tim2 &= (TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
139 
140 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
141 		tim2 |= TIM2_IHS;
142 
143 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
144 		tim2 |= TIM2_IVS;
145 
146 	if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
147 		tim2 |= TIM2_IOE;
148 
149 	if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_NEGEDGE)
150 		tim2 |= TIM2_IPC;
151 
152 	tim2 |= cpl << 16;
153 	writel(tim2, priv->regs + CLCD_TIM2);
154 	spin_unlock(&priv->tim2_lock);
155 
156 	writel(0, priv->regs + CLCD_TIM3);
157 
158 	/* Hard-code TFT panel */
159 	cntl = CNTL_LCDEN | CNTL_LCDTFT | CNTL_LCDVCOMP(1);
160 
161 	/* Note that the the hardware's format reader takes 'r' from
162 	 * the low bit, while DRM formats list channels from high bit
163 	 * to low bit as you read left to right.
164 	 */
165 	switch (fb->format->format) {
166 	case DRM_FORMAT_ABGR8888:
167 	case DRM_FORMAT_XBGR8888:
168 		cntl |= CNTL_LCDBPP24;
169 		break;
170 	case DRM_FORMAT_ARGB8888:
171 	case DRM_FORMAT_XRGB8888:
172 		cntl |= CNTL_LCDBPP24 | CNTL_BGR;
173 		break;
174 	case DRM_FORMAT_BGR565:
175 		cntl |= CNTL_LCDBPP16_565;
176 		break;
177 	case DRM_FORMAT_RGB565:
178 		cntl |= CNTL_LCDBPP16_565 | CNTL_BGR;
179 		break;
180 	case DRM_FORMAT_ABGR1555:
181 	case DRM_FORMAT_XBGR1555:
182 		cntl |= CNTL_LCDBPP16;
183 		break;
184 	case DRM_FORMAT_ARGB1555:
185 	case DRM_FORMAT_XRGB1555:
186 		cntl |= CNTL_LCDBPP16 | CNTL_BGR;
187 		break;
188 	case DRM_FORMAT_ABGR4444:
189 	case DRM_FORMAT_XBGR4444:
190 		cntl |= CNTL_LCDBPP16_444;
191 		break;
192 	case DRM_FORMAT_ARGB4444:
193 	case DRM_FORMAT_XRGB4444:
194 		cntl |= CNTL_LCDBPP16_444 | CNTL_BGR;
195 		break;
196 	default:
197 		WARN_ONCE(true, "Unknown FB format 0x%08x\n",
198 			  fb->format->format);
199 		break;
200 	}
201 
202 	/* Power sequence: first enable and chill */
203 	writel(cntl, priv->regs + priv->ctrl);
204 
205 	/*
206 	 * We expect this delay to stabilize the contrast
207 	 * voltage Vee as stipulated by the manual
208 	 */
209 	msleep(20);
210 
211 	if (priv->variant_display_enable)
212 		priv->variant_display_enable(drm, fb->format->format);
213 
214 	/* Power Up */
215 	cntl |= CNTL_LCDPWR;
216 	writel(cntl, priv->regs + priv->ctrl);
217 
218 	drm_crtc_vblank_on(crtc);
219 }
220 
221 void pl111_display_disable(struct drm_simple_display_pipe *pipe)
222 {
223 	struct drm_crtc *crtc = &pipe->crtc;
224 	struct drm_device *drm = crtc->dev;
225 	struct pl111_drm_dev_private *priv = drm->dev_private;
226 	u32 cntl;
227 
228 	drm_crtc_vblank_off(crtc);
229 
230 	/* Power Down */
231 	cntl = readl(priv->regs + priv->ctrl);
232 	if (cntl & CNTL_LCDPWR) {
233 		cntl &= ~CNTL_LCDPWR;
234 		writel(cntl, priv->regs + priv->ctrl);
235 	}
236 
237 	/*
238 	 * We expect this delay to stabilize the contrast voltage Vee as
239 	 * stipulated by the manual
240 	 */
241 	msleep(20);
242 
243 	if (priv->variant_display_disable)
244 		priv->variant_display_disable(drm);
245 
246 	/* Disable */
247 	writel(0, priv->regs + priv->ctrl);
248 
249 	clk_disable_unprepare(priv->clk);
250 }
251 
252 static void pl111_display_update(struct drm_simple_display_pipe *pipe,
253 				 struct drm_plane_state *old_pstate)
254 {
255 	struct drm_crtc *crtc = &pipe->crtc;
256 	struct drm_device *drm = crtc->dev;
257 	struct pl111_drm_dev_private *priv = drm->dev_private;
258 	struct drm_pending_vblank_event *event = crtc->state->event;
259 	struct drm_plane *plane = &pipe->plane;
260 	struct drm_plane_state *pstate = plane->state;
261 	struct drm_framebuffer *fb = pstate->fb;
262 
263 	if (fb) {
264 		u32 addr = drm_fb_cma_get_gem_addr(fb, pstate, 0);
265 
266 		writel(addr, priv->regs + CLCD_UBAS);
267 	}
268 
269 	if (event) {
270 		crtc->state->event = NULL;
271 
272 		spin_lock_irq(&crtc->dev->event_lock);
273 		if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
274 			drm_crtc_arm_vblank_event(crtc, event);
275 		else
276 			drm_crtc_send_vblank_event(crtc, event);
277 		spin_unlock_irq(&crtc->dev->event_lock);
278 	}
279 }
280 
281 int pl111_enable_vblank(struct drm_device *drm, unsigned int crtc)
282 {
283 	struct pl111_drm_dev_private *priv = drm->dev_private;
284 
285 	writel(CLCD_IRQ_NEXTBASE_UPDATE, priv->regs + priv->ienb);
286 
287 	return 0;
288 }
289 
290 void pl111_disable_vblank(struct drm_device *drm, unsigned int crtc)
291 {
292 	struct pl111_drm_dev_private *priv = drm->dev_private;
293 
294 	writel(0, priv->regs + priv->ienb);
295 }
296 
297 static int pl111_display_prepare_fb(struct drm_simple_display_pipe *pipe,
298 				    struct drm_plane_state *plane_state)
299 {
300 	return drm_gem_fb_prepare_fb(&pipe->plane, plane_state);
301 }
302 
303 static const struct drm_simple_display_pipe_funcs pl111_display_funcs = {
304 	.check = pl111_display_check,
305 	.enable = pl111_display_enable,
306 	.disable = pl111_display_disable,
307 	.update = pl111_display_update,
308 	.prepare_fb = pl111_display_prepare_fb,
309 };
310 
311 static int pl111_clk_div_choose_div(struct clk_hw *hw, unsigned long rate,
312 				    unsigned long *prate, bool set_parent)
313 {
314 	int best_div = 1, div;
315 	struct clk_hw *parent = clk_hw_get_parent(hw);
316 	unsigned long best_prate = 0;
317 	unsigned long best_diff = ~0ul;
318 	int max_div = (1 << (TIM2_PCD_LO_BITS + TIM2_PCD_HI_BITS)) - 1;
319 
320 	for (div = 1; div < max_div; div++) {
321 		unsigned long this_prate, div_rate, diff;
322 
323 		if (set_parent)
324 			this_prate = clk_hw_round_rate(parent, rate * div);
325 		else
326 			this_prate = *prate;
327 		div_rate = DIV_ROUND_UP_ULL(this_prate, div);
328 		diff = abs(rate - div_rate);
329 
330 		if (diff < best_diff) {
331 			best_div = div;
332 			best_diff = diff;
333 			best_prate = this_prate;
334 		}
335 	}
336 
337 	*prate = best_prate;
338 	return best_div;
339 }
340 
341 static long pl111_clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
342 				     unsigned long *prate)
343 {
344 	int div = pl111_clk_div_choose_div(hw, rate, prate, true);
345 
346 	return DIV_ROUND_UP_ULL(*prate, div);
347 }
348 
349 static unsigned long pl111_clk_div_recalc_rate(struct clk_hw *hw,
350 					       unsigned long prate)
351 {
352 	struct pl111_drm_dev_private *priv =
353 		container_of(hw, struct pl111_drm_dev_private, clk_div);
354 	u32 tim2 = readl(priv->regs + CLCD_TIM2);
355 	int div;
356 
357 	if (tim2 & TIM2_BCD)
358 		return prate;
359 
360 	div = tim2 & TIM2_PCD_LO_MASK;
361 	div |= (tim2 & TIM2_PCD_HI_MASK) >>
362 		(TIM2_PCD_HI_SHIFT - TIM2_PCD_LO_BITS);
363 	div += 2;
364 
365 	return DIV_ROUND_UP_ULL(prate, div);
366 }
367 
368 static int pl111_clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
369 				  unsigned long prate)
370 {
371 	struct pl111_drm_dev_private *priv =
372 		container_of(hw, struct pl111_drm_dev_private, clk_div);
373 	int div = pl111_clk_div_choose_div(hw, rate, &prate, false);
374 	u32 tim2;
375 
376 	spin_lock(&priv->tim2_lock);
377 	tim2 = readl(priv->regs + CLCD_TIM2);
378 	tim2 &= ~(TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
379 
380 	if (div == 1) {
381 		tim2 |= TIM2_BCD;
382 	} else {
383 		div -= 2;
384 		tim2 |= div & TIM2_PCD_LO_MASK;
385 		tim2 |= (div >> TIM2_PCD_LO_BITS) << TIM2_PCD_HI_SHIFT;
386 	}
387 
388 	writel(tim2, priv->regs + CLCD_TIM2);
389 	spin_unlock(&priv->tim2_lock);
390 
391 	return 0;
392 }
393 
394 static const struct clk_ops pl111_clk_div_ops = {
395 	.recalc_rate = pl111_clk_div_recalc_rate,
396 	.round_rate = pl111_clk_div_round_rate,
397 	.set_rate = pl111_clk_div_set_rate,
398 };
399 
400 static int
401 pl111_init_clock_divider(struct drm_device *drm)
402 {
403 	struct pl111_drm_dev_private *priv = drm->dev_private;
404 	struct clk *parent = devm_clk_get(drm->dev, "clcdclk");
405 	struct clk_hw *div = &priv->clk_div;
406 	const char *parent_name;
407 	struct clk_init_data init = {
408 		.name = "pl111_div",
409 		.ops = &pl111_clk_div_ops,
410 		.parent_names = &parent_name,
411 		.num_parents = 1,
412 		.flags = CLK_SET_RATE_PARENT,
413 	};
414 	int ret;
415 
416 	if (IS_ERR(parent)) {
417 		dev_err(drm->dev, "CLCD: unable to get clcdclk.\n");
418 		return PTR_ERR(parent);
419 	}
420 	parent_name = __clk_get_name(parent);
421 
422 	spin_lock_init(&priv->tim2_lock);
423 	div->init = &init;
424 
425 	ret = devm_clk_hw_register(drm->dev, div);
426 
427 	priv->clk = div->clk;
428 	return ret;
429 }
430 
431 int pl111_display_init(struct drm_device *drm)
432 {
433 	struct pl111_drm_dev_private *priv = drm->dev_private;
434 	struct device *dev = drm->dev;
435 	struct device_node *endpoint;
436 	u32 tft_r0b0g0[3];
437 	int ret;
438 
439 	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
440 	if (!endpoint)
441 		return -ENODEV;
442 
443 	if (of_property_read_u32_array(endpoint,
444 				       "arm,pl11x,tft-r0g0b0-pads",
445 				       tft_r0b0g0,
446 				       ARRAY_SIZE(tft_r0b0g0)) != 0) {
447 		dev_err(dev, "arm,pl11x,tft-r0g0b0-pads should be 3 ints\n");
448 		of_node_put(endpoint);
449 		return -ENOENT;
450 	}
451 	of_node_put(endpoint);
452 
453 	ret = pl111_init_clock_divider(drm);
454 	if (ret)
455 		return ret;
456 
457 	ret = drm_simple_display_pipe_init(drm, &priv->pipe,
458 					   &pl111_display_funcs,
459 					   priv->variant->formats,
460 					   priv->variant->nformats,
461 					   NULL,
462 					   priv->connector);
463 	if (ret)
464 		return ret;
465 
466 	return 0;
467 }
468