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_panel.h>
25 #include <drm/drm_gem_cma_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.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 	drm_panel_prepare(priv->connector.panel);
159 
160 	/* Enable and Power Up */
161 	cntl = CNTL_LCDEN | CNTL_LCDTFT | CNTL_LCDPWR | CNTL_LCDVCOMP(1);
162 
163 	/* Note that the the hardware's format reader takes 'r' from
164 	 * the low bit, while DRM formats list channels from high bit
165 	 * to low bit as you read left to right.
166 	 */
167 	switch (fb->format->format) {
168 	case DRM_FORMAT_ABGR8888:
169 	case DRM_FORMAT_XBGR8888:
170 		cntl |= CNTL_LCDBPP24;
171 		break;
172 	case DRM_FORMAT_ARGB8888:
173 	case DRM_FORMAT_XRGB8888:
174 		cntl |= CNTL_LCDBPP24 | CNTL_BGR;
175 		break;
176 	case DRM_FORMAT_BGR565:
177 		cntl |= CNTL_LCDBPP16_565;
178 		break;
179 	case DRM_FORMAT_RGB565:
180 		cntl |= CNTL_LCDBPP16_565 | CNTL_BGR;
181 		break;
182 	case DRM_FORMAT_ABGR1555:
183 	case DRM_FORMAT_XBGR1555:
184 		cntl |= CNTL_LCDBPP16;
185 		break;
186 	case DRM_FORMAT_ARGB1555:
187 	case DRM_FORMAT_XRGB1555:
188 		cntl |= CNTL_LCDBPP16 | CNTL_BGR;
189 		break;
190 	case DRM_FORMAT_ABGR4444:
191 	case DRM_FORMAT_XBGR4444:
192 		cntl |= CNTL_LCDBPP16_444;
193 		break;
194 	case DRM_FORMAT_ARGB4444:
195 	case DRM_FORMAT_XRGB4444:
196 		cntl |= CNTL_LCDBPP16_444 | CNTL_BGR;
197 		break;
198 	default:
199 		WARN_ONCE(true, "Unknown FB format 0x%08x\n",
200 			  fb->format->format);
201 		break;
202 	}
203 
204 	writel(cntl, priv->regs + CLCD_PL111_CNTL);
205 
206 	drm_panel_enable(priv->connector.panel);
207 
208 	drm_crtc_vblank_on(crtc);
209 }
210 
211 void pl111_display_disable(struct drm_simple_display_pipe *pipe)
212 {
213 	struct drm_crtc *crtc = &pipe->crtc;
214 	struct drm_device *drm = crtc->dev;
215 	struct pl111_drm_dev_private *priv = drm->dev_private;
216 
217 	drm_crtc_vblank_off(crtc);
218 
219 	drm_panel_disable(priv->connector.panel);
220 
221 	/* Disable and Power Down */
222 	writel(0, priv->regs + CLCD_PL111_CNTL);
223 
224 	drm_panel_unprepare(priv->connector.panel);
225 
226 	clk_disable_unprepare(priv->clk);
227 }
228 
229 static void pl111_display_update(struct drm_simple_display_pipe *pipe,
230 				 struct drm_plane_state *old_pstate)
231 {
232 	struct drm_crtc *crtc = &pipe->crtc;
233 	struct drm_device *drm = crtc->dev;
234 	struct pl111_drm_dev_private *priv = drm->dev_private;
235 	struct drm_pending_vblank_event *event = crtc->state->event;
236 	struct drm_plane *plane = &pipe->plane;
237 	struct drm_plane_state *pstate = plane->state;
238 	struct drm_framebuffer *fb = pstate->fb;
239 
240 	if (fb) {
241 		u32 addr = drm_fb_cma_get_gem_addr(fb, pstate, 0);
242 
243 		writel(addr, priv->regs + CLCD_UBAS);
244 	}
245 
246 	if (event) {
247 		crtc->state->event = NULL;
248 
249 		spin_lock_irq(&crtc->dev->event_lock);
250 		if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
251 			drm_crtc_arm_vblank_event(crtc, event);
252 		else
253 			drm_crtc_send_vblank_event(crtc, event);
254 		spin_unlock_irq(&crtc->dev->event_lock);
255 	}
256 }
257 
258 int pl111_enable_vblank(struct drm_device *drm, unsigned int crtc)
259 {
260 	struct pl111_drm_dev_private *priv = drm->dev_private;
261 
262 	writel(CLCD_IRQ_NEXTBASE_UPDATE, priv->regs + CLCD_PL111_IENB);
263 
264 	return 0;
265 }
266 
267 void pl111_disable_vblank(struct drm_device *drm, unsigned int crtc)
268 {
269 	struct pl111_drm_dev_private *priv = drm->dev_private;
270 
271 	writel(0, priv->regs + CLCD_PL111_IENB);
272 }
273 
274 static int pl111_display_prepare_fb(struct drm_simple_display_pipe *pipe,
275 				    struct drm_plane_state *plane_state)
276 {
277 	return drm_fb_cma_prepare_fb(&pipe->plane, plane_state);
278 }
279 
280 static const struct drm_simple_display_pipe_funcs pl111_display_funcs = {
281 	.check = pl111_display_check,
282 	.enable = pl111_display_enable,
283 	.disable = pl111_display_disable,
284 	.update = pl111_display_update,
285 	.prepare_fb = pl111_display_prepare_fb,
286 };
287 
288 static int pl111_clk_div_choose_div(struct clk_hw *hw, unsigned long rate,
289 				    unsigned long *prate, bool set_parent)
290 {
291 	int best_div = 1, div;
292 	struct clk_hw *parent = clk_hw_get_parent(hw);
293 	unsigned long best_prate = 0;
294 	unsigned long best_diff = ~0ul;
295 	int max_div = (1 << (TIM2_PCD_LO_BITS + TIM2_PCD_HI_BITS)) - 1;
296 
297 	for (div = 1; div < max_div; div++) {
298 		unsigned long this_prate, div_rate, diff;
299 
300 		if (set_parent)
301 			this_prate = clk_hw_round_rate(parent, rate * div);
302 		else
303 			this_prate = *prate;
304 		div_rate = DIV_ROUND_UP_ULL(this_prate, div);
305 		diff = abs(rate - div_rate);
306 
307 		if (diff < best_diff) {
308 			best_div = div;
309 			best_diff = diff;
310 			best_prate = this_prate;
311 		}
312 	}
313 
314 	*prate = best_prate;
315 	return best_div;
316 }
317 
318 static long pl111_clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
319 				     unsigned long *prate)
320 {
321 	int div = pl111_clk_div_choose_div(hw, rate, prate, true);
322 
323 	return DIV_ROUND_UP_ULL(*prate, div);
324 }
325 
326 static unsigned long pl111_clk_div_recalc_rate(struct clk_hw *hw,
327 					       unsigned long prate)
328 {
329 	struct pl111_drm_dev_private *priv =
330 		container_of(hw, struct pl111_drm_dev_private, clk_div);
331 	u32 tim2 = readl(priv->regs + CLCD_TIM2);
332 	int div;
333 
334 	if (tim2 & TIM2_BCD)
335 		return prate;
336 
337 	div = tim2 & TIM2_PCD_LO_MASK;
338 	div |= (tim2 & TIM2_PCD_HI_MASK) >>
339 		(TIM2_PCD_HI_SHIFT - TIM2_PCD_LO_BITS);
340 	div += 2;
341 
342 	return DIV_ROUND_UP_ULL(prate, div);
343 }
344 
345 static int pl111_clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
346 				  unsigned long prate)
347 {
348 	struct pl111_drm_dev_private *priv =
349 		container_of(hw, struct pl111_drm_dev_private, clk_div);
350 	int div = pl111_clk_div_choose_div(hw, rate, &prate, false);
351 	u32 tim2;
352 
353 	spin_lock(&priv->tim2_lock);
354 	tim2 = readl(priv->regs + CLCD_TIM2);
355 	tim2 &= ~(TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
356 
357 	if (div == 1) {
358 		tim2 |= TIM2_BCD;
359 	} else {
360 		div -= 2;
361 		tim2 |= div & TIM2_PCD_LO_MASK;
362 		tim2 |= (div >> TIM2_PCD_LO_BITS) << TIM2_PCD_HI_SHIFT;
363 	}
364 
365 	writel(tim2, priv->regs + CLCD_TIM2);
366 	spin_unlock(&priv->tim2_lock);
367 
368 	return 0;
369 }
370 
371 static const struct clk_ops pl111_clk_div_ops = {
372 	.recalc_rate = pl111_clk_div_recalc_rate,
373 	.round_rate = pl111_clk_div_round_rate,
374 	.set_rate = pl111_clk_div_set_rate,
375 };
376 
377 static int
378 pl111_init_clock_divider(struct drm_device *drm)
379 {
380 	struct pl111_drm_dev_private *priv = drm->dev_private;
381 	struct clk *parent = devm_clk_get(drm->dev, "clcdclk");
382 	struct clk_hw *div = &priv->clk_div;
383 	const char *parent_name;
384 	struct clk_init_data init = {
385 		.name = "pl111_div",
386 		.ops = &pl111_clk_div_ops,
387 		.parent_names = &parent_name,
388 		.num_parents = 1,
389 		.flags = CLK_SET_RATE_PARENT,
390 	};
391 	int ret;
392 
393 	if (IS_ERR(parent)) {
394 		dev_err(drm->dev, "CLCD: unable to get clcdclk.\n");
395 		return PTR_ERR(parent);
396 	}
397 	parent_name = __clk_get_name(parent);
398 
399 	spin_lock_init(&priv->tim2_lock);
400 	div->init = &init;
401 
402 	ret = devm_clk_hw_register(drm->dev, div);
403 
404 	priv->clk = div->clk;
405 	return ret;
406 }
407 
408 int pl111_display_init(struct drm_device *drm)
409 {
410 	struct pl111_drm_dev_private *priv = drm->dev_private;
411 	struct device *dev = drm->dev;
412 	struct device_node *endpoint;
413 	u32 tft_r0b0g0[3];
414 	int ret;
415 	static const u32 formats[] = {
416 		DRM_FORMAT_ABGR8888,
417 		DRM_FORMAT_XBGR8888,
418 		DRM_FORMAT_ARGB8888,
419 		DRM_FORMAT_XRGB8888,
420 		DRM_FORMAT_BGR565,
421 		DRM_FORMAT_RGB565,
422 		DRM_FORMAT_ABGR1555,
423 		DRM_FORMAT_XBGR1555,
424 		DRM_FORMAT_ARGB1555,
425 		DRM_FORMAT_XRGB1555,
426 		DRM_FORMAT_ABGR4444,
427 		DRM_FORMAT_XBGR4444,
428 		DRM_FORMAT_ARGB4444,
429 		DRM_FORMAT_XRGB4444,
430 	};
431 
432 	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
433 	if (!endpoint)
434 		return -ENODEV;
435 
436 	if (of_property_read_u32_array(endpoint,
437 				       "arm,pl11x,tft-r0g0b0-pads",
438 				       tft_r0b0g0,
439 				       ARRAY_SIZE(tft_r0b0g0)) != 0) {
440 		dev_err(dev, "arm,pl11x,tft-r0g0b0-pads should be 3 ints\n");
441 		of_node_put(endpoint);
442 		return -ENOENT;
443 	}
444 	of_node_put(endpoint);
445 
446 	if (tft_r0b0g0[0] != 0 ||
447 	    tft_r0b0g0[1] != 8 ||
448 	    tft_r0b0g0[2] != 16) {
449 		dev_err(dev, "arm,pl11x,tft-r0g0b0-pads != [0,8,16] not yet supported\n");
450 		return -EINVAL;
451 	}
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 					   formats, ARRAY_SIZE(formats),
460 					   &priv->connector.connector);
461 	if (ret)
462 		return ret;
463 
464 	return 0;
465 }
466