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_gem_framebuffer_helper.h>
27 #include <drm/drm_fb_cma_helper.h>
28 
29 #include "pl111_drm.h"
30 
31 irqreturn_t pl111_irq(int irq, void *data)
32 {
33 	struct pl111_drm_dev_private *priv = data;
34 	u32 irq_stat;
35 	irqreturn_t status = IRQ_NONE;
36 
37 	irq_stat = readl(priv->regs + CLCD_PL111_MIS);
38 
39 	if (!irq_stat)
40 		return IRQ_NONE;
41 
42 	if (irq_stat & CLCD_IRQ_NEXTBASE_UPDATE) {
43 		drm_crtc_handle_vblank(&priv->pipe.crtc);
44 
45 		status = IRQ_HANDLED;
46 	}
47 
48 	/* Clear the interrupt once done */
49 	writel(irq_stat, priv->regs + CLCD_PL111_ICR);
50 
51 	return status;
52 }
53 
54 static int pl111_display_check(struct drm_simple_display_pipe *pipe,
55 			       struct drm_plane_state *pstate,
56 			       struct drm_crtc_state *cstate)
57 {
58 	const struct drm_display_mode *mode = &cstate->mode;
59 	struct drm_framebuffer *old_fb = pipe->plane.state->fb;
60 	struct drm_framebuffer *fb = pstate->fb;
61 
62 	if (mode->hdisplay % 16)
63 		return -EINVAL;
64 
65 	if (fb) {
66 		u32 offset = drm_fb_cma_get_gem_addr(fb, pstate, 0);
67 
68 		/* FB base address must be dword aligned. */
69 		if (offset & 3)
70 			return -EINVAL;
71 
72 		/* There's no pitch register -- the mode's hdisplay
73 		 * controls it.
74 		 */
75 		if (fb->pitches[0] != mode->hdisplay * fb->format->cpp[0])
76 			return -EINVAL;
77 
78 		/* We can't change the FB format in a flicker-free
79 		 * manner (and only update it during CRTC enable).
80 		 */
81 		if (old_fb && old_fb->format != fb->format)
82 			cstate->mode_changed = true;
83 	}
84 
85 	return 0;
86 }
87 
88 static void pl111_display_enable(struct drm_simple_display_pipe *pipe,
89 				 struct drm_crtc_state *cstate)
90 {
91 	struct drm_crtc *crtc = &pipe->crtc;
92 	struct drm_plane *plane = &pipe->plane;
93 	struct drm_device *drm = crtc->dev;
94 	struct pl111_drm_dev_private *priv = drm->dev_private;
95 	const struct drm_display_mode *mode = &cstate->mode;
96 	struct drm_framebuffer *fb = plane->state->fb;
97 	struct drm_connector *connector = &priv->connector.connector;
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 (mode->flags & DRM_MODE_FLAG_NHSYNC)
142 		tim2 |= TIM2_IHS;
143 
144 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
145 		tim2 |= TIM2_IVS;
146 
147 	if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
148 		tim2 |= TIM2_IOE;
149 
150 	if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_NEGEDGE)
151 		tim2 |= TIM2_IPC;
152 
153 	tim2 |= cpl << 16;
154 	writel(tim2, priv->regs + CLCD_TIM2);
155 	spin_unlock(&priv->tim2_lock);
156 
157 	writel(0, priv->regs + CLCD_TIM3);
158 
159 	drm_panel_prepare(priv->connector.panel);
160 
161 	/* Enable and Power Up */
162 	cntl = CNTL_LCDEN | CNTL_LCDTFT | CNTL_LCDPWR | CNTL_LCDVCOMP(1);
163 
164 	/* Note that the the hardware's format reader takes 'r' from
165 	 * the low bit, while DRM formats list channels from high bit
166 	 * to low bit as you read left to right.
167 	 */
168 	switch (fb->format->format) {
169 	case DRM_FORMAT_ABGR8888:
170 	case DRM_FORMAT_XBGR8888:
171 		cntl |= CNTL_LCDBPP24;
172 		break;
173 	case DRM_FORMAT_ARGB8888:
174 	case DRM_FORMAT_XRGB8888:
175 		cntl |= CNTL_LCDBPP24 | CNTL_BGR;
176 		break;
177 	case DRM_FORMAT_BGR565:
178 		cntl |= CNTL_LCDBPP16_565;
179 		break;
180 	case DRM_FORMAT_RGB565:
181 		cntl |= CNTL_LCDBPP16_565 | CNTL_BGR;
182 		break;
183 	case DRM_FORMAT_ABGR1555:
184 	case DRM_FORMAT_XBGR1555:
185 		cntl |= CNTL_LCDBPP16;
186 		break;
187 	case DRM_FORMAT_ARGB1555:
188 	case DRM_FORMAT_XRGB1555:
189 		cntl |= CNTL_LCDBPP16 | CNTL_BGR;
190 		break;
191 	case DRM_FORMAT_ABGR4444:
192 	case DRM_FORMAT_XBGR4444:
193 		cntl |= CNTL_LCDBPP16_444;
194 		break;
195 	case DRM_FORMAT_ARGB4444:
196 	case DRM_FORMAT_XRGB4444:
197 		cntl |= CNTL_LCDBPP16_444 | CNTL_BGR;
198 		break;
199 	default:
200 		WARN_ONCE(true, "Unknown FB format 0x%08x\n",
201 			  fb->format->format);
202 		break;
203 	}
204 
205 	writel(cntl, priv->regs + CLCD_PL111_CNTL);
206 
207 	drm_panel_enable(priv->connector.panel);
208 
209 	drm_crtc_vblank_on(crtc);
210 }
211 
212 void pl111_display_disable(struct drm_simple_display_pipe *pipe)
213 {
214 	struct drm_crtc *crtc = &pipe->crtc;
215 	struct drm_device *drm = crtc->dev;
216 	struct pl111_drm_dev_private *priv = drm->dev_private;
217 
218 	drm_crtc_vblank_off(crtc);
219 
220 	drm_panel_disable(priv->connector.panel);
221 
222 	/* Disable and Power Down */
223 	writel(0, priv->regs + CLCD_PL111_CNTL);
224 
225 	drm_panel_unprepare(priv->connector.panel);
226 
227 	clk_disable_unprepare(priv->clk);
228 }
229 
230 static void pl111_display_update(struct drm_simple_display_pipe *pipe,
231 				 struct drm_plane_state *old_pstate)
232 {
233 	struct drm_crtc *crtc = &pipe->crtc;
234 	struct drm_device *drm = crtc->dev;
235 	struct pl111_drm_dev_private *priv = drm->dev_private;
236 	struct drm_pending_vblank_event *event = crtc->state->event;
237 	struct drm_plane *plane = &pipe->plane;
238 	struct drm_plane_state *pstate = plane->state;
239 	struct drm_framebuffer *fb = pstate->fb;
240 
241 	if (fb) {
242 		u32 addr = drm_fb_cma_get_gem_addr(fb, pstate, 0);
243 
244 		writel(addr, priv->regs + CLCD_UBAS);
245 	}
246 
247 	if (event) {
248 		crtc->state->event = NULL;
249 
250 		spin_lock_irq(&crtc->dev->event_lock);
251 		if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
252 			drm_crtc_arm_vblank_event(crtc, event);
253 		else
254 			drm_crtc_send_vblank_event(crtc, event);
255 		spin_unlock_irq(&crtc->dev->event_lock);
256 	}
257 }
258 
259 int pl111_enable_vblank(struct drm_device *drm, unsigned int crtc)
260 {
261 	struct pl111_drm_dev_private *priv = drm->dev_private;
262 
263 	writel(CLCD_IRQ_NEXTBASE_UPDATE, priv->regs + CLCD_PL111_IENB);
264 
265 	return 0;
266 }
267 
268 void pl111_disable_vblank(struct drm_device *drm, unsigned int crtc)
269 {
270 	struct pl111_drm_dev_private *priv = drm->dev_private;
271 
272 	writel(0, priv->regs + CLCD_PL111_IENB);
273 }
274 
275 static int pl111_display_prepare_fb(struct drm_simple_display_pipe *pipe,
276 				    struct drm_plane_state *plane_state)
277 {
278 	return drm_gem_fb_prepare_fb(&pipe->plane, plane_state);
279 }
280 
281 static const struct drm_simple_display_pipe_funcs pl111_display_funcs = {
282 	.check = pl111_display_check,
283 	.enable = pl111_display_enable,
284 	.disable = pl111_display_disable,
285 	.update = pl111_display_update,
286 	.prepare_fb = pl111_display_prepare_fb,
287 };
288 
289 static int pl111_clk_div_choose_div(struct clk_hw *hw, unsigned long rate,
290 				    unsigned long *prate, bool set_parent)
291 {
292 	int best_div = 1, div;
293 	struct clk_hw *parent = clk_hw_get_parent(hw);
294 	unsigned long best_prate = 0;
295 	unsigned long best_diff = ~0ul;
296 	int max_div = (1 << (TIM2_PCD_LO_BITS + TIM2_PCD_HI_BITS)) - 1;
297 
298 	for (div = 1; div < max_div; div++) {
299 		unsigned long this_prate, div_rate, diff;
300 
301 		if (set_parent)
302 			this_prate = clk_hw_round_rate(parent, rate * div);
303 		else
304 			this_prate = *prate;
305 		div_rate = DIV_ROUND_UP_ULL(this_prate, div);
306 		diff = abs(rate - div_rate);
307 
308 		if (diff < best_diff) {
309 			best_div = div;
310 			best_diff = diff;
311 			best_prate = this_prate;
312 		}
313 	}
314 
315 	*prate = best_prate;
316 	return best_div;
317 }
318 
319 static long pl111_clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
320 				     unsigned long *prate)
321 {
322 	int div = pl111_clk_div_choose_div(hw, rate, prate, true);
323 
324 	return DIV_ROUND_UP_ULL(*prate, div);
325 }
326 
327 static unsigned long pl111_clk_div_recalc_rate(struct clk_hw *hw,
328 					       unsigned long prate)
329 {
330 	struct pl111_drm_dev_private *priv =
331 		container_of(hw, struct pl111_drm_dev_private, clk_div);
332 	u32 tim2 = readl(priv->regs + CLCD_TIM2);
333 	int div;
334 
335 	if (tim2 & TIM2_BCD)
336 		return prate;
337 
338 	div = tim2 & TIM2_PCD_LO_MASK;
339 	div |= (tim2 & TIM2_PCD_HI_MASK) >>
340 		(TIM2_PCD_HI_SHIFT - TIM2_PCD_LO_BITS);
341 	div += 2;
342 
343 	return DIV_ROUND_UP_ULL(prate, div);
344 }
345 
346 static int pl111_clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
347 				  unsigned long prate)
348 {
349 	struct pl111_drm_dev_private *priv =
350 		container_of(hw, struct pl111_drm_dev_private, clk_div);
351 	int div = pl111_clk_div_choose_div(hw, rate, &prate, false);
352 	u32 tim2;
353 
354 	spin_lock(&priv->tim2_lock);
355 	tim2 = readl(priv->regs + CLCD_TIM2);
356 	tim2 &= ~(TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
357 
358 	if (div == 1) {
359 		tim2 |= TIM2_BCD;
360 	} else {
361 		div -= 2;
362 		tim2 |= div & TIM2_PCD_LO_MASK;
363 		tim2 |= (div >> TIM2_PCD_LO_BITS) << TIM2_PCD_HI_SHIFT;
364 	}
365 
366 	writel(tim2, priv->regs + CLCD_TIM2);
367 	spin_unlock(&priv->tim2_lock);
368 
369 	return 0;
370 }
371 
372 static const struct clk_ops pl111_clk_div_ops = {
373 	.recalc_rate = pl111_clk_div_recalc_rate,
374 	.round_rate = pl111_clk_div_round_rate,
375 	.set_rate = pl111_clk_div_set_rate,
376 };
377 
378 static int
379 pl111_init_clock_divider(struct drm_device *drm)
380 {
381 	struct pl111_drm_dev_private *priv = drm->dev_private;
382 	struct clk *parent = devm_clk_get(drm->dev, "clcdclk");
383 	struct clk_hw *div = &priv->clk_div;
384 	const char *parent_name;
385 	struct clk_init_data init = {
386 		.name = "pl111_div",
387 		.ops = &pl111_clk_div_ops,
388 		.parent_names = &parent_name,
389 		.num_parents = 1,
390 		.flags = CLK_SET_RATE_PARENT,
391 	};
392 	int ret;
393 
394 	if (IS_ERR(parent)) {
395 		dev_err(drm->dev, "CLCD: unable to get clcdclk.\n");
396 		return PTR_ERR(parent);
397 	}
398 	parent_name = __clk_get_name(parent);
399 
400 	spin_lock_init(&priv->tim2_lock);
401 	div->init = &init;
402 
403 	ret = devm_clk_hw_register(drm->dev, div);
404 
405 	priv->clk = div->clk;
406 	return ret;
407 }
408 
409 int pl111_display_init(struct drm_device *drm)
410 {
411 	struct pl111_drm_dev_private *priv = drm->dev_private;
412 	struct device *dev = drm->dev;
413 	struct device_node *endpoint;
414 	u32 tft_r0b0g0[3];
415 	int ret;
416 	static const u32 formats[] = {
417 		DRM_FORMAT_ABGR8888,
418 		DRM_FORMAT_XBGR8888,
419 		DRM_FORMAT_ARGB8888,
420 		DRM_FORMAT_XRGB8888,
421 		DRM_FORMAT_BGR565,
422 		DRM_FORMAT_RGB565,
423 		DRM_FORMAT_ABGR1555,
424 		DRM_FORMAT_XBGR1555,
425 		DRM_FORMAT_ARGB1555,
426 		DRM_FORMAT_XRGB1555,
427 		DRM_FORMAT_ABGR4444,
428 		DRM_FORMAT_XBGR4444,
429 		DRM_FORMAT_ARGB4444,
430 		DRM_FORMAT_XRGB4444,
431 	};
432 
433 	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
434 	if (!endpoint)
435 		return -ENODEV;
436 
437 	if (of_property_read_u32_array(endpoint,
438 				       "arm,pl11x,tft-r0g0b0-pads",
439 				       tft_r0b0g0,
440 				       ARRAY_SIZE(tft_r0b0g0)) != 0) {
441 		dev_err(dev, "arm,pl11x,tft-r0g0b0-pads should be 3 ints\n");
442 		of_node_put(endpoint);
443 		return -ENOENT;
444 	}
445 	of_node_put(endpoint);
446 
447 	if (tft_r0b0g0[0] != 0 ||
448 	    tft_r0b0g0[1] != 8 ||
449 	    tft_r0b0g0[2] != 16) {
450 		dev_err(dev, "arm,pl11x,tft-r0g0b0-pads != [0,8,16] not yet supported\n");
451 		return -EINVAL;
452 	}
453 
454 	ret = pl111_init_clock_divider(drm);
455 	if (ret)
456 		return ret;
457 
458 	ret = drm_simple_display_pipe_init(drm, &priv->pipe,
459 					   &pl111_display_funcs,
460 					   formats, ARRAY_SIZE(formats),
461 					   NULL, &priv->connector.connector);
462 	if (ret)
463 		return ret;
464 
465 	return 0;
466 }
467