1 /*
2  * Copyright (C) 2015 Free Electrons
3  * Copyright (C) 2015 NextThing Co
4  *
5  * Maxime Ripard <maxime.ripard@free-electrons.com>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation; either version 2 of
10  * the License, or (at your option) any later version.
11  */
12 
13 #include <drm/drmP.h>
14 #include <drm/drm_atomic_helper.h>
15 #include <drm/drm_crtc.h>
16 #include <drm/drm_crtc_helper.h>
17 #include <drm/drm_fb_cma_helper.h>
18 #include <drm/drm_gem_cma_helper.h>
19 #include <drm/drm_plane_helper.h>
20 
21 #include <linux/component.h>
22 #include <linux/list.h>
23 #include <linux/of_device.h>
24 #include <linux/of_graph.h>
25 #include <linux/reset.h>
26 
27 #include "sun4i_backend.h"
28 #include "sun4i_drv.h"
29 #include "sun4i_layer.h"
30 #include "sunxi_engine.h"
31 
32 struct sun4i_backend_quirks {
33 	/* backend <-> TCON muxing selection done in backend */
34 	bool needs_output_muxing;
35 };
36 
37 static const u32 sunxi_rgb2yuv_coef[12] = {
38 	0x00000107, 0x00000204, 0x00000064, 0x00000108,
39 	0x00003f69, 0x00003ed6, 0x000001c1, 0x00000808,
40 	0x000001c1, 0x00003e88, 0x00003fb8, 0x00000808
41 };
42 
43 static void sun4i_backend_apply_color_correction(struct sunxi_engine *engine)
44 {
45 	int i;
46 
47 	DRM_DEBUG_DRIVER("Applying RGB to YUV color correction\n");
48 
49 	/* Set color correction */
50 	regmap_write(engine->regs, SUN4I_BACKEND_OCCTL_REG,
51 		     SUN4I_BACKEND_OCCTL_ENABLE);
52 
53 	for (i = 0; i < 12; i++)
54 		regmap_write(engine->regs, SUN4I_BACKEND_OCRCOEF_REG(i),
55 			     sunxi_rgb2yuv_coef[i]);
56 }
57 
58 static void sun4i_backend_disable_color_correction(struct sunxi_engine *engine)
59 {
60 	DRM_DEBUG_DRIVER("Disabling color correction\n");
61 
62 	/* Disable color correction */
63 	regmap_update_bits(engine->regs, SUN4I_BACKEND_OCCTL_REG,
64 			   SUN4I_BACKEND_OCCTL_ENABLE, 0);
65 }
66 
67 static void sun4i_backend_commit(struct sunxi_engine *engine)
68 {
69 	DRM_DEBUG_DRIVER("Committing changes\n");
70 
71 	regmap_write(engine->regs, SUN4I_BACKEND_REGBUFFCTL_REG,
72 		     SUN4I_BACKEND_REGBUFFCTL_AUTOLOAD_DIS |
73 		     SUN4I_BACKEND_REGBUFFCTL_LOADCTL);
74 }
75 
76 void sun4i_backend_layer_enable(struct sun4i_backend *backend,
77 				int layer, bool enable)
78 {
79 	u32 val;
80 
81 	DRM_DEBUG_DRIVER("%sabling layer %d\n", enable ? "En" : "Dis",
82 			 layer);
83 
84 	if (enable)
85 		val = SUN4I_BACKEND_MODCTL_LAY_EN(layer);
86 	else
87 		val = 0;
88 
89 	regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
90 			   SUN4I_BACKEND_MODCTL_LAY_EN(layer), val);
91 }
92 
93 static int sun4i_backend_drm_format_to_layer(struct drm_plane *plane,
94 					     u32 format, u32 *mode)
95 {
96 	if ((plane->type == DRM_PLANE_TYPE_PRIMARY) &&
97 	    (format == DRM_FORMAT_ARGB8888))
98 		format = DRM_FORMAT_XRGB8888;
99 
100 	switch (format) {
101 	case DRM_FORMAT_ARGB8888:
102 		*mode = SUN4I_BACKEND_LAY_FBFMT_ARGB8888;
103 		break;
104 
105 	case DRM_FORMAT_ARGB4444:
106 		*mode = SUN4I_BACKEND_LAY_FBFMT_ARGB4444;
107 		break;
108 
109 	case DRM_FORMAT_ARGB1555:
110 		*mode = SUN4I_BACKEND_LAY_FBFMT_ARGB1555;
111 		break;
112 
113 	case DRM_FORMAT_RGBA5551:
114 		*mode = SUN4I_BACKEND_LAY_FBFMT_RGBA5551;
115 		break;
116 
117 	case DRM_FORMAT_RGBA4444:
118 		*mode = SUN4I_BACKEND_LAY_FBFMT_RGBA4444;
119 		break;
120 
121 	case DRM_FORMAT_XRGB8888:
122 		*mode = SUN4I_BACKEND_LAY_FBFMT_XRGB8888;
123 		break;
124 
125 	case DRM_FORMAT_RGB888:
126 		*mode = SUN4I_BACKEND_LAY_FBFMT_RGB888;
127 		break;
128 
129 	case DRM_FORMAT_RGB565:
130 		*mode = SUN4I_BACKEND_LAY_FBFMT_RGB565;
131 		break;
132 
133 	default:
134 		return -EINVAL;
135 	}
136 
137 	return 0;
138 }
139 
140 int sun4i_backend_update_layer_coord(struct sun4i_backend *backend,
141 				     int layer, struct drm_plane *plane)
142 {
143 	struct drm_plane_state *state = plane->state;
144 	struct drm_framebuffer *fb = state->fb;
145 
146 	DRM_DEBUG_DRIVER("Updating layer %d\n", layer);
147 
148 	if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
149 		DRM_DEBUG_DRIVER("Primary layer, updating global size W: %u H: %u\n",
150 				 state->crtc_w, state->crtc_h);
151 		regmap_write(backend->engine.regs, SUN4I_BACKEND_DISSIZE_REG,
152 			     SUN4I_BACKEND_DISSIZE(state->crtc_w,
153 						   state->crtc_h));
154 	}
155 
156 	/* Set the line width */
157 	DRM_DEBUG_DRIVER("Layer line width: %d bits\n", fb->pitches[0] * 8);
158 	regmap_write(backend->engine.regs,
159 		     SUN4I_BACKEND_LAYLINEWIDTH_REG(layer),
160 		     fb->pitches[0] * 8);
161 
162 	/* Set height and width */
163 	DRM_DEBUG_DRIVER("Layer size W: %u H: %u\n",
164 			 state->crtc_w, state->crtc_h);
165 	regmap_write(backend->engine.regs, SUN4I_BACKEND_LAYSIZE_REG(layer),
166 		     SUN4I_BACKEND_LAYSIZE(state->crtc_w,
167 					   state->crtc_h));
168 
169 	/* Set base coordinates */
170 	DRM_DEBUG_DRIVER("Layer coordinates X: %d Y: %d\n",
171 			 state->crtc_x, state->crtc_y);
172 	regmap_write(backend->engine.regs, SUN4I_BACKEND_LAYCOOR_REG(layer),
173 		     SUN4I_BACKEND_LAYCOOR(state->crtc_x,
174 					   state->crtc_y));
175 
176 	return 0;
177 }
178 
179 int sun4i_backend_update_layer_formats(struct sun4i_backend *backend,
180 				       int layer, struct drm_plane *plane)
181 {
182 	struct drm_plane_state *state = plane->state;
183 	struct drm_framebuffer *fb = state->fb;
184 	bool interlaced = false;
185 	u32 val;
186 	int ret;
187 
188 	if (plane->state->crtc)
189 		interlaced = plane->state->crtc->state->adjusted_mode.flags
190 			& DRM_MODE_FLAG_INTERLACE;
191 
192 	regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
193 			   SUN4I_BACKEND_MODCTL_ITLMOD_EN,
194 			   interlaced ? SUN4I_BACKEND_MODCTL_ITLMOD_EN : 0);
195 
196 	DRM_DEBUG_DRIVER("Switching display backend interlaced mode %s\n",
197 			 interlaced ? "on" : "off");
198 
199 	ret = sun4i_backend_drm_format_to_layer(plane, fb->format->format,
200 						&val);
201 	if (ret) {
202 		DRM_DEBUG_DRIVER("Invalid format\n");
203 		return ret;
204 	}
205 
206 	regmap_update_bits(backend->engine.regs,
207 			   SUN4I_BACKEND_ATTCTL_REG1(layer),
208 			   SUN4I_BACKEND_ATTCTL_REG1_LAY_FBFMT, val);
209 
210 	return 0;
211 }
212 
213 int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend,
214 				      int layer, struct drm_plane *plane)
215 {
216 	struct drm_plane_state *state = plane->state;
217 	struct drm_framebuffer *fb = state->fb;
218 	u32 lo_paddr, hi_paddr;
219 	dma_addr_t paddr;
220 
221 	/* Get the start of the displayed memory */
222 	paddr = drm_fb_cma_get_gem_addr(fb, state, 0);
223 	DRM_DEBUG_DRIVER("Setting buffer address to %pad\n", &paddr);
224 
225 	/*
226 	 * backend DMA accesses DRAM directly, bypassing the system
227 	 * bus. As such, the address range is different and the buffer
228 	 * address needs to be corrected.
229 	 */
230 	paddr -= PHYS_OFFSET;
231 
232 	/* Write the 32 lower bits of the address (in bits) */
233 	lo_paddr = paddr << 3;
234 	DRM_DEBUG_DRIVER("Setting address lower bits to 0x%x\n", lo_paddr);
235 	regmap_write(backend->engine.regs,
236 		     SUN4I_BACKEND_LAYFB_L32ADD_REG(layer),
237 		     lo_paddr);
238 
239 	/* And the upper bits */
240 	hi_paddr = paddr >> 29;
241 	DRM_DEBUG_DRIVER("Setting address high bits to 0x%x\n", hi_paddr);
242 	regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_LAYFB_H4ADD_REG,
243 			   SUN4I_BACKEND_LAYFB_H4ADD_MSK(layer),
244 			   SUN4I_BACKEND_LAYFB_H4ADD(layer, hi_paddr));
245 
246 	return 0;
247 }
248 
249 static int sun4i_backend_init_sat(struct device *dev) {
250 	struct sun4i_backend *backend = dev_get_drvdata(dev);
251 	int ret;
252 
253 	backend->sat_reset = devm_reset_control_get(dev, "sat");
254 	if (IS_ERR(backend->sat_reset)) {
255 		dev_err(dev, "Couldn't get the SAT reset line\n");
256 		return PTR_ERR(backend->sat_reset);
257 	}
258 
259 	ret = reset_control_deassert(backend->sat_reset);
260 	if (ret) {
261 		dev_err(dev, "Couldn't deassert the SAT reset line\n");
262 		return ret;
263 	}
264 
265 	backend->sat_clk = devm_clk_get(dev, "sat");
266 	if (IS_ERR(backend->sat_clk)) {
267 		dev_err(dev, "Couldn't get our SAT clock\n");
268 		ret = PTR_ERR(backend->sat_clk);
269 		goto err_assert_reset;
270 	}
271 
272 	ret = clk_prepare_enable(backend->sat_clk);
273 	if (ret) {
274 		dev_err(dev, "Couldn't enable the SAT clock\n");
275 		return ret;
276 	}
277 
278 	return 0;
279 
280 err_assert_reset:
281 	reset_control_assert(backend->sat_reset);
282 	return ret;
283 }
284 
285 static int sun4i_backend_free_sat(struct device *dev) {
286 	struct sun4i_backend *backend = dev_get_drvdata(dev);
287 
288 	clk_disable_unprepare(backend->sat_clk);
289 	reset_control_assert(backend->sat_reset);
290 
291 	return 0;
292 }
293 
294 /*
295  * The display backend can take video output from the display frontend, or
296  * the display enhancement unit on the A80, as input for one it its layers.
297  * This relationship within the display pipeline is encoded in the device
298  * tree with of_graph, and we use it here to figure out which backend, if
299  * there are 2 or more, we are currently probing. The number would be in
300  * the "reg" property of the upstream output port endpoint.
301  */
302 static int sun4i_backend_of_get_id(struct device_node *node)
303 {
304 	struct device_node *port, *ep;
305 	int ret = -EINVAL;
306 
307 	/* input is port 0 */
308 	port = of_graph_get_port_by_id(node, 0);
309 	if (!port)
310 		return -EINVAL;
311 
312 	/* try finding an upstream endpoint */
313 	for_each_available_child_of_node(port, ep) {
314 		struct device_node *remote;
315 		u32 reg;
316 
317 		remote = of_graph_get_remote_endpoint(ep);
318 		if (!remote)
319 			continue;
320 
321 		ret = of_property_read_u32(remote, "reg", &reg);
322 		if (ret)
323 			continue;
324 
325 		ret = reg;
326 	}
327 
328 	of_node_put(port);
329 
330 	return ret;
331 }
332 
333 static const struct sunxi_engine_ops sun4i_backend_engine_ops = {
334 	.commit				= sun4i_backend_commit,
335 	.layers_init			= sun4i_layers_init,
336 	.apply_color_correction		= sun4i_backend_apply_color_correction,
337 	.disable_color_correction	= sun4i_backend_disable_color_correction,
338 };
339 
340 static struct regmap_config sun4i_backend_regmap_config = {
341 	.reg_bits	= 32,
342 	.val_bits	= 32,
343 	.reg_stride	= 4,
344 	.max_register	= 0x5800,
345 };
346 
347 static int sun4i_backend_bind(struct device *dev, struct device *master,
348 			      void *data)
349 {
350 	struct platform_device *pdev = to_platform_device(dev);
351 	struct drm_device *drm = data;
352 	struct sun4i_drv *drv = drm->dev_private;
353 	struct sun4i_backend *backend;
354 	const struct sun4i_backend_quirks *quirks;
355 	struct resource *res;
356 	void __iomem *regs;
357 	int i, ret;
358 
359 	backend = devm_kzalloc(dev, sizeof(*backend), GFP_KERNEL);
360 	if (!backend)
361 		return -ENOMEM;
362 	dev_set_drvdata(dev, backend);
363 
364 	backend->engine.node = dev->of_node;
365 	backend->engine.ops = &sun4i_backend_engine_ops;
366 	backend->engine.id = sun4i_backend_of_get_id(dev->of_node);
367 	if (backend->engine.id < 0)
368 		return backend->engine.id;
369 
370 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
371 	regs = devm_ioremap_resource(dev, res);
372 	if (IS_ERR(regs))
373 		return PTR_ERR(regs);
374 
375 	backend->reset = devm_reset_control_get(dev, NULL);
376 	if (IS_ERR(backend->reset)) {
377 		dev_err(dev, "Couldn't get our reset line\n");
378 		return PTR_ERR(backend->reset);
379 	}
380 
381 	ret = reset_control_deassert(backend->reset);
382 	if (ret) {
383 		dev_err(dev, "Couldn't deassert our reset line\n");
384 		return ret;
385 	}
386 
387 	backend->bus_clk = devm_clk_get(dev, "ahb");
388 	if (IS_ERR(backend->bus_clk)) {
389 		dev_err(dev, "Couldn't get the backend bus clock\n");
390 		ret = PTR_ERR(backend->bus_clk);
391 		goto err_assert_reset;
392 	}
393 	clk_prepare_enable(backend->bus_clk);
394 
395 	backend->mod_clk = devm_clk_get(dev, "mod");
396 	if (IS_ERR(backend->mod_clk)) {
397 		dev_err(dev, "Couldn't get the backend module clock\n");
398 		ret = PTR_ERR(backend->mod_clk);
399 		goto err_disable_bus_clk;
400 	}
401 	clk_prepare_enable(backend->mod_clk);
402 
403 	backend->ram_clk = devm_clk_get(dev, "ram");
404 	if (IS_ERR(backend->ram_clk)) {
405 		dev_err(dev, "Couldn't get the backend RAM clock\n");
406 		ret = PTR_ERR(backend->ram_clk);
407 		goto err_disable_mod_clk;
408 	}
409 	clk_prepare_enable(backend->ram_clk);
410 
411 	if (of_device_is_compatible(dev->of_node,
412 				    "allwinner,sun8i-a33-display-backend")) {
413 		ret = sun4i_backend_init_sat(dev);
414 		if (ret) {
415 			dev_err(dev, "Couldn't init SAT resources\n");
416 			goto err_disable_ram_clk;
417 		}
418 	}
419 
420 	backend->engine.regs = devm_regmap_init_mmio(dev, regs,
421 						     &sun4i_backend_regmap_config);
422 	if (IS_ERR(backend->engine.regs)) {
423 		dev_err(dev, "Couldn't create the backend regmap\n");
424 		return PTR_ERR(backend->engine.regs);
425 	}
426 
427 	list_add_tail(&backend->engine.list, &drv->engine_list);
428 
429 	/*
430 	 * Many of the backend's layer configuration registers have
431 	 * undefined default values. This poses a risk as we use
432 	 * regmap_update_bits in some places, and don't overwrite
433 	 * the whole register.
434 	 *
435 	 * Clear the registers here to have something predictable.
436 	 */
437 	for (i = 0x800; i < 0x1000; i += 4)
438 		regmap_write(backend->engine.regs, i, 0);
439 
440 	/* Disable registers autoloading */
441 	regmap_write(backend->engine.regs, SUN4I_BACKEND_REGBUFFCTL_REG,
442 		     SUN4I_BACKEND_REGBUFFCTL_AUTOLOAD_DIS);
443 
444 	/* Enable the backend */
445 	regmap_write(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
446 		     SUN4I_BACKEND_MODCTL_DEBE_EN |
447 		     SUN4I_BACKEND_MODCTL_START_CTL);
448 
449 	/* Set output selection if needed */
450 	quirks = of_device_get_match_data(dev);
451 	if (quirks->needs_output_muxing) {
452 		/*
453 		 * We assume there is no dynamic muxing of backends
454 		 * and TCONs, so we select the backend with same ID.
455 		 *
456 		 * While dynamic selection might be interesting, since
457 		 * the CRTC is tied to the TCON, while the layers are
458 		 * tied to the backends, this means, we will need to
459 		 * switch between groups of layers. There might not be
460 		 * a way to represent this constraint in DRM.
461 		 */
462 		regmap_update_bits(backend->engine.regs,
463 				   SUN4I_BACKEND_MODCTL_REG,
464 				   SUN4I_BACKEND_MODCTL_OUT_SEL,
465 				   (backend->engine.id
466 				    ? SUN4I_BACKEND_MODCTL_OUT_LCD1
467 				    : SUN4I_BACKEND_MODCTL_OUT_LCD0));
468 	}
469 
470 	return 0;
471 
472 err_disable_ram_clk:
473 	clk_disable_unprepare(backend->ram_clk);
474 err_disable_mod_clk:
475 	clk_disable_unprepare(backend->mod_clk);
476 err_disable_bus_clk:
477 	clk_disable_unprepare(backend->bus_clk);
478 err_assert_reset:
479 	reset_control_assert(backend->reset);
480 	return ret;
481 }
482 
483 static void sun4i_backend_unbind(struct device *dev, struct device *master,
484 				 void *data)
485 {
486 	struct sun4i_backend *backend = dev_get_drvdata(dev);
487 
488 	list_del(&backend->engine.list);
489 
490 	if (of_device_is_compatible(dev->of_node,
491 				    "allwinner,sun8i-a33-display-backend"))
492 		sun4i_backend_free_sat(dev);
493 
494 	clk_disable_unprepare(backend->ram_clk);
495 	clk_disable_unprepare(backend->mod_clk);
496 	clk_disable_unprepare(backend->bus_clk);
497 	reset_control_assert(backend->reset);
498 }
499 
500 static const struct component_ops sun4i_backend_ops = {
501 	.bind	= sun4i_backend_bind,
502 	.unbind	= sun4i_backend_unbind,
503 };
504 
505 static int sun4i_backend_probe(struct platform_device *pdev)
506 {
507 	return component_add(&pdev->dev, &sun4i_backend_ops);
508 }
509 
510 static int sun4i_backend_remove(struct platform_device *pdev)
511 {
512 	component_del(&pdev->dev, &sun4i_backend_ops);
513 
514 	return 0;
515 }
516 
517 static const struct sun4i_backend_quirks sun4i_backend_quirks = {
518 	.needs_output_muxing = true,
519 };
520 
521 static const struct sun4i_backend_quirks sun5i_backend_quirks = {
522 };
523 
524 static const struct sun4i_backend_quirks sun6i_backend_quirks = {
525 };
526 
527 static const struct sun4i_backend_quirks sun7i_backend_quirks = {
528 	.needs_output_muxing = true,
529 };
530 
531 static const struct sun4i_backend_quirks sun8i_a33_backend_quirks = {
532 };
533 
534 static const struct of_device_id sun4i_backend_of_table[] = {
535 	{
536 		.compatible = "allwinner,sun4i-a10-display-backend",
537 		.data = &sun4i_backend_quirks,
538 	},
539 	{
540 		.compatible = "allwinner,sun5i-a13-display-backend",
541 		.data = &sun5i_backend_quirks,
542 	},
543 	{
544 		.compatible = "allwinner,sun6i-a31-display-backend",
545 		.data = &sun6i_backend_quirks,
546 	},
547 	{
548 		.compatible = "allwinner,sun7i-a20-display-backend",
549 		.data = &sun7i_backend_quirks,
550 	},
551 	{
552 		.compatible = "allwinner,sun8i-a33-display-backend",
553 		.data = &sun8i_a33_backend_quirks,
554 	},
555 	{ }
556 };
557 MODULE_DEVICE_TABLE(of, sun4i_backend_of_table);
558 
559 static struct platform_driver sun4i_backend_platform_driver = {
560 	.probe		= sun4i_backend_probe,
561 	.remove		= sun4i_backend_remove,
562 	.driver		= {
563 		.name		= "sun4i-backend",
564 		.of_match_table	= sun4i_backend_of_table,
565 	},
566 };
567 module_platform_driver(sun4i_backend_platform_driver);
568 
569 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
570 MODULE_DESCRIPTION("Allwinner A10 Display Backend Driver");
571 MODULE_LICENSE("GPL");
572