1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2015 Free Electrons
4 * Copyright (C) 2015 NextThing Co
5 *
6 * Maxime Ripard <maxime.ripard@free-electrons.com>
7 */
8
9#include <linux/component.h>
10#include <linux/list.h>
11#include <linux/module.h>
12#include <linux/of_device.h>
13#include <linux/of_graph.h>
14#include <linux/dma-mapping.h>
15#include <linux/platform_device.h>
16#include <linux/reset.h>
17
18#include <drm/drm_atomic.h>
19#include <drm/drm_atomic_helper.h>
20#include <drm/drm_crtc.h>
21#include <drm/drm_fb_cma_helper.h>
22#include <drm/drm_fourcc.h>
23#include <drm/drm_gem_cma_helper.h>
24#include <drm/drm_plane_helper.h>
25#include <drm/drm_probe_helper.h>
26
27#include "sun4i_backend.h"
28#include "sun4i_drv.h"
29#include "sun4i_frontend.h"
30#include "sun4i_layer.h"
31#include "sunxi_engine.h"
32
33struct sun4i_backend_quirks {
34	/* backend <-> TCON muxing selection done in backend */
35	bool needs_output_muxing;
36
37	/* alpha at the lowest z position is not always supported */
38	bool supports_lowest_plane_alpha;
39};
40
41static const u32 sunxi_rgb2yuv_coef[12] = {
42	0x00000107, 0x00000204, 0x00000064, 0x00000108,
43	0x00003f69, 0x00003ed6, 0x000001c1, 0x00000808,
44	0x000001c1, 0x00003e88, 0x00003fb8, 0x00000808
45};
46
47static void sun4i_backend_apply_color_correction(struct sunxi_engine *engine)
48{
49	int i;
50
51	DRM_DEBUG_DRIVER("Applying RGB to YUV color correction\n");
52
53	/* Set color correction */
54	regmap_write(engine->regs, SUN4I_BACKEND_OCCTL_REG,
55		     SUN4I_BACKEND_OCCTL_ENABLE);
56
57	for (i = 0; i < 12; i++)
58		regmap_write(engine->regs, SUN4I_BACKEND_OCRCOEF_REG(i),
59			     sunxi_rgb2yuv_coef[i]);
60}
61
62static void sun4i_backend_disable_color_correction(struct sunxi_engine *engine)
63{
64	DRM_DEBUG_DRIVER("Disabling color correction\n");
65
66	/* Disable color correction */
67	regmap_update_bits(engine->regs, SUN4I_BACKEND_OCCTL_REG,
68			   SUN4I_BACKEND_OCCTL_ENABLE, 0);
69}
70
71static void sun4i_backend_commit(struct sunxi_engine *engine)
72{
73	DRM_DEBUG_DRIVER("Committing changes\n");
74
75	regmap_write(engine->regs, SUN4I_BACKEND_REGBUFFCTL_REG,
76		     SUN4I_BACKEND_REGBUFFCTL_AUTOLOAD_DIS |
77		     SUN4I_BACKEND_REGBUFFCTL_LOADCTL);
78}
79
80void sun4i_backend_layer_enable(struct sun4i_backend *backend,
81				int layer, bool enable)
82{
83	u32 val;
84
85	DRM_DEBUG_DRIVER("%sabling layer %d\n", enable ? "En" : "Dis",
86			 layer);
87
88	if (enable)
89		val = SUN4I_BACKEND_MODCTL_LAY_EN(layer);
90	else
91		val = 0;
92
93	regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
94			   SUN4I_BACKEND_MODCTL_LAY_EN(layer), val);
95}
96
97static int sun4i_backend_drm_format_to_layer(u32 format, u32 *mode)
98{
99	switch (format) {
100	case DRM_FORMAT_ARGB8888:
101		*mode = SUN4I_BACKEND_LAY_FBFMT_ARGB8888;
102		break;
103
104	case DRM_FORMAT_ARGB4444:
105		*mode = SUN4I_BACKEND_LAY_FBFMT_ARGB4444;
106		break;
107
108	case DRM_FORMAT_ARGB1555:
109		*mode = SUN4I_BACKEND_LAY_FBFMT_ARGB1555;
110		break;
111
112	case DRM_FORMAT_RGBA5551:
113		*mode = SUN4I_BACKEND_LAY_FBFMT_RGBA5551;
114		break;
115
116	case DRM_FORMAT_RGBA4444:
117		*mode = SUN4I_BACKEND_LAY_FBFMT_RGBA4444;
118		break;
119
120	case DRM_FORMAT_XRGB8888:
121		*mode = SUN4I_BACKEND_LAY_FBFMT_XRGB8888;
122		break;
123
124	case DRM_FORMAT_RGB888:
125		*mode = SUN4I_BACKEND_LAY_FBFMT_RGB888;
126		break;
127
128	case DRM_FORMAT_RGB565:
129		*mode = SUN4I_BACKEND_LAY_FBFMT_RGB565;
130		break;
131
132	default:
133		return -EINVAL;
134	}
135
136	return 0;
137}
138
139static const uint32_t sun4i_backend_formats[] = {
140	DRM_FORMAT_ARGB1555,
141	DRM_FORMAT_ARGB4444,
142	DRM_FORMAT_ARGB8888,
143	DRM_FORMAT_RGB565,
144	DRM_FORMAT_RGB888,
145	DRM_FORMAT_RGBA4444,
146	DRM_FORMAT_RGBA5551,
147	DRM_FORMAT_UYVY,
148	DRM_FORMAT_VYUY,
149	DRM_FORMAT_XRGB8888,
150	DRM_FORMAT_YUYV,
151	DRM_FORMAT_YVYU,
152};
153
154bool sun4i_backend_format_is_supported(uint32_t fmt, uint64_t modifier)
155{
156	unsigned int i;
157
158	if (modifier != DRM_FORMAT_MOD_LINEAR)
159		return false;
160
161	for (i = 0; i < ARRAY_SIZE(sun4i_backend_formats); i++)
162		if (sun4i_backend_formats[i] == fmt)
163			return true;
164
165	return false;
166}
167
168int sun4i_backend_update_layer_coord(struct sun4i_backend *backend,
169				     int layer, struct drm_plane *plane)
170{
171	struct drm_plane_state *state = plane->state;
172
173	DRM_DEBUG_DRIVER("Updating layer %d\n", layer);
174
175	if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
176		DRM_DEBUG_DRIVER("Primary layer, updating global size W: %u H: %u\n",
177				 state->crtc_w, state->crtc_h);
178		regmap_write(backend->engine.regs, SUN4I_BACKEND_DISSIZE_REG,
179			     SUN4I_BACKEND_DISSIZE(state->crtc_w,
180						   state->crtc_h));
181	}
182
183	/* Set height and width */
184	DRM_DEBUG_DRIVER("Layer size W: %u H: %u\n",
185			 state->crtc_w, state->crtc_h);
186	regmap_write(backend->engine.regs, SUN4I_BACKEND_LAYSIZE_REG(layer),
187		     SUN4I_BACKEND_LAYSIZE(state->crtc_w,
188					   state->crtc_h));
189
190	/* Set base coordinates */
191	DRM_DEBUG_DRIVER("Layer coordinates X: %d Y: %d\n",
192			 state->crtc_x, state->crtc_y);
193	regmap_write(backend->engine.regs, SUN4I_BACKEND_LAYCOOR_REG(layer),
194		     SUN4I_BACKEND_LAYCOOR(state->crtc_x,
195					   state->crtc_y));
196
197	return 0;
198}
199
200static int sun4i_backend_update_yuv_format(struct sun4i_backend *backend,
201					   int layer, struct drm_plane *plane)
202{
203	struct drm_plane_state *state = plane->state;
204	struct drm_framebuffer *fb = state->fb;
205	const struct drm_format_info *format = fb->format;
206	const uint32_t fmt = format->format;
207	u32 val = SUN4I_BACKEND_IYUVCTL_EN;
208	int i;
209
210	for (i = 0; i < ARRAY_SIZE(sunxi_bt601_yuv2rgb_coef); i++)
211		regmap_write(backend->engine.regs,
212			     SUN4I_BACKEND_YGCOEF_REG(i),
213			     sunxi_bt601_yuv2rgb_coef[i]);
214
215	/*
216	 * We should do that only for a single plane, but the
217	 * framebuffer's atomic_check has our back on this.
218	 */
219	regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
220			   SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN,
221			   SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN);
222
223	/* TODO: Add support for the multi-planar YUV formats */
224	if (drm_format_info_is_yuv_packed(format) &&
225	    drm_format_info_is_yuv_sampling_422(format))
226		val |= SUN4I_BACKEND_IYUVCTL_FBFMT_PACKED_YUV422;
227	else
228		DRM_DEBUG_DRIVER("Unsupported YUV format (0x%x)\n", fmt);
229
230	/*
231	 * Allwinner seems to list the pixel sequence from right to left, while
232	 * DRM lists it from left to right.
233	 */
234	switch (fmt) {
235	case DRM_FORMAT_YUYV:
236		val |= SUN4I_BACKEND_IYUVCTL_FBPS_VYUY;
237		break;
238	case DRM_FORMAT_YVYU:
239		val |= SUN4I_BACKEND_IYUVCTL_FBPS_UYVY;
240		break;
241	case DRM_FORMAT_UYVY:
242		val |= SUN4I_BACKEND_IYUVCTL_FBPS_YVYU;
243		break;
244	case DRM_FORMAT_VYUY:
245		val |= SUN4I_BACKEND_IYUVCTL_FBPS_YUYV;
246		break;
247	default:
248		DRM_DEBUG_DRIVER("Unsupported YUV pixel sequence (0x%x)\n",
249				 fmt);
250	}
251
252	regmap_write(backend->engine.regs, SUN4I_BACKEND_IYUVCTL_REG, val);
253
254	return 0;
255}
256
257int sun4i_backend_update_layer_formats(struct sun4i_backend *backend,
258				       int layer, struct drm_plane *plane)
259{
260	struct drm_plane_state *state = plane->state;
261	struct drm_framebuffer *fb = state->fb;
262	bool interlaced = false;
263	u32 val;
264	int ret;
265
266	/* Clear the YUV mode */
267	regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
268			   SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN, 0);
269
270	if (plane->state->crtc)
271		interlaced = plane->state->crtc->state->adjusted_mode.flags
272			& DRM_MODE_FLAG_INTERLACE;
273
274	regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
275			   SUN4I_BACKEND_MODCTL_ITLMOD_EN,
276			   interlaced ? SUN4I_BACKEND_MODCTL_ITLMOD_EN : 0);
277
278	DRM_DEBUG_DRIVER("Switching display backend interlaced mode %s\n",
279			 interlaced ? "on" : "off");
280
281	val = SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA(state->alpha >> 8);
282	if (state->alpha != DRM_BLEND_ALPHA_OPAQUE)
283		val |= SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_EN;
284	regmap_update_bits(backend->engine.regs,
285			   SUN4I_BACKEND_ATTCTL_REG0(layer),
286			   SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_MASK |
287			   SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_EN,
288			   val);
289
290	if (fb->format->is_yuv)
291		return sun4i_backend_update_yuv_format(backend, layer, plane);
292
293	ret = sun4i_backend_drm_format_to_layer(fb->format->format, &val);
294	if (ret) {
295		DRM_DEBUG_DRIVER("Invalid format\n");
296		return ret;
297	}
298
299	regmap_update_bits(backend->engine.regs,
300			   SUN4I_BACKEND_ATTCTL_REG1(layer),
301			   SUN4I_BACKEND_ATTCTL_REG1_LAY_FBFMT, val);
302
303	return 0;
304}
305
306int sun4i_backend_update_layer_frontend(struct sun4i_backend *backend,
307					int layer, uint32_t fmt)
308{
309	u32 val;
310	int ret;
311
312	ret = sun4i_backend_drm_format_to_layer(fmt, &val);
313	if (ret) {
314		DRM_DEBUG_DRIVER("Invalid format\n");
315		return ret;
316	}
317
318	regmap_update_bits(backend->engine.regs,
319			   SUN4I_BACKEND_ATTCTL_REG0(layer),
320			   SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN,
321			   SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN);
322
323	regmap_update_bits(backend->engine.regs,
324			   SUN4I_BACKEND_ATTCTL_REG1(layer),
325			   SUN4I_BACKEND_ATTCTL_REG1_LAY_FBFMT, val);
326
327	return 0;
328}
329
330static int sun4i_backend_update_yuv_buffer(struct sun4i_backend *backend,
331					   struct drm_framebuffer *fb,
332					   dma_addr_t paddr)
333{
334	/* TODO: Add support for the multi-planar YUV formats */
335	DRM_DEBUG_DRIVER("Setting packed YUV buffer address to %pad\n", &paddr);
336	regmap_write(backend->engine.regs, SUN4I_BACKEND_IYUVADD_REG(0), paddr);
337
338	DRM_DEBUG_DRIVER("Layer line width: %d bits\n", fb->pitches[0] * 8);
339	regmap_write(backend->engine.regs, SUN4I_BACKEND_IYUVLINEWIDTH_REG(0),
340		     fb->pitches[0] * 8);
341
342	return 0;
343}
344
345int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend,
346				      int layer, struct drm_plane *plane)
347{
348	struct drm_plane_state *state = plane->state;
349	struct drm_framebuffer *fb = state->fb;
350	u32 lo_paddr, hi_paddr;
351	dma_addr_t paddr;
352
353	/* Set the line width */
354	DRM_DEBUG_DRIVER("Layer line width: %d bits\n", fb->pitches[0] * 8);
355	regmap_write(backend->engine.regs,
356		     SUN4I_BACKEND_LAYLINEWIDTH_REG(layer),
357		     fb->pitches[0] * 8);
358
359	/* Get the start of the displayed memory */
360	paddr = drm_fb_cma_get_gem_addr(fb, state, 0);
361	DRM_DEBUG_DRIVER("Setting buffer address to %pad\n", &paddr);
362
363	if (fb->format->is_yuv)
364		return sun4i_backend_update_yuv_buffer(backend, fb, paddr);
365
366	/* Write the 32 lower bits of the address (in bits) */
367	lo_paddr = paddr << 3;
368	DRM_DEBUG_DRIVER("Setting address lower bits to 0x%x\n", lo_paddr);
369	regmap_write(backend->engine.regs,
370		     SUN4I_BACKEND_LAYFB_L32ADD_REG(layer),
371		     lo_paddr);
372
373	/* And the upper bits */
374	hi_paddr = paddr >> 29;
375	DRM_DEBUG_DRIVER("Setting address high bits to 0x%x\n", hi_paddr);
376	regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_LAYFB_H4ADD_REG,
377			   SUN4I_BACKEND_LAYFB_H4ADD_MSK(layer),
378			   SUN4I_BACKEND_LAYFB_H4ADD(layer, hi_paddr));
379
380	return 0;
381}
382
383int sun4i_backend_update_layer_zpos(struct sun4i_backend *backend, int layer,
384				    struct drm_plane *plane)
385{
386	struct drm_plane_state *state = plane->state;
387	struct sun4i_layer_state *p_state = state_to_sun4i_layer_state(state);
388	unsigned int priority = state->normalized_zpos;
389	unsigned int pipe = p_state->pipe;
390
391	DRM_DEBUG_DRIVER("Setting layer %d's priority to %d and pipe %d\n",
392			 layer, priority, pipe);
393	regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
394			   SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL_MASK |
395			   SUN4I_BACKEND_ATTCTL_REG0_LAY_PRISEL_MASK,
396			   SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL(p_state->pipe) |
397			   SUN4I_BACKEND_ATTCTL_REG0_LAY_PRISEL(priority));
398
399	return 0;
400}
401
402void sun4i_backend_cleanup_layer(struct sun4i_backend *backend,
403				 int layer)
404{
405	regmap_update_bits(backend->engine.regs,
406			   SUN4I_BACKEND_ATTCTL_REG0(layer),
407			   SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN |
408			   SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN, 0);
409}
410
411static bool sun4i_backend_plane_uses_scaler(struct drm_plane_state *state)
412{
413	u16 src_h = state->src_h >> 16;
414	u16 src_w = state->src_w >> 16;
415
416	DRM_DEBUG_DRIVER("Input size %dx%d, output size %dx%d\n",
417			 src_w, src_h, state->crtc_w, state->crtc_h);
418
419	if ((state->crtc_h != src_h) || (state->crtc_w != src_w))
420		return true;
421
422	return false;
423}
424
425static bool sun4i_backend_plane_uses_frontend(struct drm_plane_state *state)
426{
427	struct sun4i_layer *layer = plane_to_sun4i_layer(state->plane);
428	struct sun4i_backend *backend = layer->backend;
429	uint32_t format = state->fb->format->format;
430	uint64_t modifier = state->fb->modifier;
431
432	if (IS_ERR(backend->frontend))
433		return false;
434
435	if (!sun4i_frontend_format_is_supported(format, modifier))
436		return false;
437
438	if (!sun4i_backend_format_is_supported(format, modifier))
439		return true;
440
441	/*
442	 * TODO: The backend alone allows 2x and 4x integer scaling, including
443	 * support for an alpha component (which the frontend doesn't support).
444	 * Use the backend directly instead of the frontend in this case, with
445	 * another test to return false.
446	 */
447
448	if (sun4i_backend_plane_uses_scaler(state))
449		return true;
450
451	/*
452	 * Here the format is supported by both the frontend and the backend
453	 * and no frontend scaling is required, so use the backend directly.
454	 */
455	return false;
456}
457
458static bool sun4i_backend_plane_is_supported(struct drm_plane_state *state,
459					     bool *uses_frontend)
460{
461	if (sun4i_backend_plane_uses_frontend(state)) {
462		*uses_frontend = true;
463		return true;
464	}
465
466	*uses_frontend = false;
467
468	/* Scaling is not supported without the frontend. */
469	if (sun4i_backend_plane_uses_scaler(state))
470		return false;
471
472	return true;
473}
474
475static void sun4i_backend_atomic_begin(struct sunxi_engine *engine,
476				       struct drm_crtc_state *old_state)
477{
478	u32 val;
479
480	WARN_ON(regmap_read_poll_timeout(engine->regs,
481					 SUN4I_BACKEND_REGBUFFCTL_REG,
482					 val, !(val & SUN4I_BACKEND_REGBUFFCTL_LOADCTL),
483					 100, 50000));
484}
485
486static int sun4i_backend_atomic_check(struct sunxi_engine *engine,
487				      struct drm_crtc_state *crtc_state)
488{
489	struct drm_plane_state *plane_states[SUN4I_BACKEND_NUM_LAYERS] = { 0 };
490	struct sun4i_backend *backend = engine_to_sun4i_backend(engine);
491	struct drm_atomic_state *state = crtc_state->state;
492	struct drm_device *drm = state->dev;
493	struct drm_plane *plane;
494	unsigned int num_planes = 0;
495	unsigned int num_alpha_planes = 0;
496	unsigned int num_frontend_planes = 0;
497	unsigned int num_alpha_planes_max = 1;
498	unsigned int num_yuv_planes = 0;
499	unsigned int current_pipe = 0;
500	unsigned int i;
501
502	DRM_DEBUG_DRIVER("Starting checking our planes\n");
503
504	if (!crtc_state->planes_changed)
505		return 0;
506
507	drm_for_each_plane_mask(plane, drm, crtc_state->plane_mask) {
508		struct drm_plane_state *plane_state =
509			drm_atomic_get_plane_state(state, plane);
510		struct sun4i_layer_state *layer_state =
511			state_to_sun4i_layer_state(plane_state);
512		struct drm_framebuffer *fb = plane_state->fb;
513		struct drm_format_name_buf format_name;
514
515		if (!sun4i_backend_plane_is_supported(plane_state,
516						      &layer_state->uses_frontend))
517			return -EINVAL;
518
519		if (layer_state->uses_frontend) {
520			DRM_DEBUG_DRIVER("Using the frontend for plane %d\n",
521					 plane->index);
522			num_frontend_planes++;
523		} else {
524			if (fb->format->is_yuv) {
525				DRM_DEBUG_DRIVER("Plane FB format is YUV\n");
526				num_yuv_planes++;
527			}
528		}
529
530		DRM_DEBUG_DRIVER("Plane FB format is %s\n",
531				 drm_get_format_name(fb->format->format,
532						     &format_name));
533		if (fb->format->has_alpha || (plane_state->alpha != DRM_BLEND_ALPHA_OPAQUE))
534			num_alpha_planes++;
535
536		DRM_DEBUG_DRIVER("Plane zpos is %d\n",
537				 plane_state->normalized_zpos);
538
539		/* Sort our planes by Zpos */
540		plane_states[plane_state->normalized_zpos] = plane_state;
541
542		num_planes++;
543	}
544
545	/* All our planes were disabled, bail out */
546	if (!num_planes)
547		return 0;
548
549	/*
550	 * The hardware is a bit unusual here.
551	 *
552	 * Even though it supports 4 layers, it does the composition
553	 * in two separate steps.
554	 *
555	 * The first one is assigning a layer to one of its two
556	 * pipes. If more that 1 layer is assigned to the same pipe,
557	 * and if pixels overlaps, the pipe will take the pixel from
558	 * the layer with the highest priority.
559	 *
560	 * The second step is the actual alpha blending, that takes
561	 * the two pipes as input, and uses the potential alpha
562	 * component to do the transparency between the two.
563	 *
564	 * This two-step scenario makes us unable to guarantee a
565	 * robust alpha blending between the 4 layers in all
566	 * situations, since this means that we need to have one layer
567	 * with alpha at the lowest position of our two pipes.
568	 *
569	 * However, we cannot even do that on every platform, since
570	 * the hardware has a bug where the lowest plane of the lowest
571	 * pipe (pipe 0, priority 0), if it has any alpha, will
572	 * discard the pixel data entirely and just display the pixels
573	 * in the background color (black by default).
574	 *
575	 * This means that on the affected platforms, we effectively
576	 * have only three valid configurations with alpha, all of
577	 * them with the alpha being on pipe1 with the lowest
578	 * position, which can be 1, 2 or 3 depending on the number of
579	 * planes and their zpos.
580	 */
581
582	/* For platforms that are not affected by the issue described above. */
583	if (backend->quirks->supports_lowest_plane_alpha)
584		num_alpha_planes_max++;
585
586	if (num_alpha_planes > num_alpha_planes_max) {
587		DRM_DEBUG_DRIVER("Too many planes with alpha, rejecting...\n");
588		return -EINVAL;
589	}
590
591	/* We can't have an alpha plane at the lowest position */
592	if (!backend->quirks->supports_lowest_plane_alpha &&
593	    (plane_states[0]->alpha != DRM_BLEND_ALPHA_OPAQUE))
594		return -EINVAL;
595
596	for (i = 1; i < num_planes; i++) {
597		struct drm_plane_state *p_state = plane_states[i];
598		struct drm_framebuffer *fb = p_state->fb;
599		struct sun4i_layer_state *s_state = state_to_sun4i_layer_state(p_state);
600
601		/*
602		 * The only alpha position is the lowest plane of the
603		 * second pipe.
604		 */
605		if (fb->format->has_alpha || (p_state->alpha != DRM_BLEND_ALPHA_OPAQUE))
606			current_pipe++;
607
608		s_state->pipe = current_pipe;
609	}
610
611	/* We can only have a single YUV plane at a time */
612	if (num_yuv_planes > SUN4I_BACKEND_NUM_YUV_PLANES) {
613		DRM_DEBUG_DRIVER("Too many planes with YUV, rejecting...\n");
614		return -EINVAL;
615	}
616
617	if (num_frontend_planes > SUN4I_BACKEND_NUM_FRONTEND_LAYERS) {
618		DRM_DEBUG_DRIVER("Too many planes going through the frontend, rejecting\n");
619		return -EINVAL;
620	}
621
622	DRM_DEBUG_DRIVER("State valid with %u planes, %u alpha, %u video, %u YUV\n",
623			 num_planes, num_alpha_planes, num_frontend_planes,
624			 num_yuv_planes);
625
626	return 0;
627}
628
629static void sun4i_backend_vblank_quirk(struct sunxi_engine *engine)
630{
631	struct sun4i_backend *backend = engine_to_sun4i_backend(engine);
632	struct sun4i_frontend *frontend = backend->frontend;
633
634	if (!frontend)
635		return;
636
637	/*
638	 * In a teardown scenario with the frontend involved, we have
639	 * to keep the frontend enabled until the next vblank, and
640	 * only then disable it.
641	 *
642	 * This is due to the fact that the backend will not take into
643	 * account the new configuration (with the plane that used to
644	 * be fed by the frontend now disabled) until we write to the
645	 * commit bit and the hardware fetches the new configuration
646	 * during the next vblank.
647	 *
648	 * So we keep the frontend around in order to prevent any
649	 * visual artifacts.
650	 */
651	spin_lock(&backend->frontend_lock);
652	if (backend->frontend_teardown) {
653		sun4i_frontend_exit(frontend);
654		backend->frontend_teardown = false;
655	}
656	spin_unlock(&backend->frontend_lock);
657};
658
659static int sun4i_backend_init_sat(struct device *dev) {
660	struct sun4i_backend *backend = dev_get_drvdata(dev);
661	int ret;
662
663	backend->sat_reset = devm_reset_control_get(dev, "sat");
664	if (IS_ERR(backend->sat_reset)) {
665		dev_err(dev, "Couldn't get the SAT reset line\n");
666		return PTR_ERR(backend->sat_reset);
667	}
668
669	ret = reset_control_deassert(backend->sat_reset);
670	if (ret) {
671		dev_err(dev, "Couldn't deassert the SAT reset line\n");
672		return ret;
673	}
674
675	backend->sat_clk = devm_clk_get(dev, "sat");
676	if (IS_ERR(backend->sat_clk)) {
677		dev_err(dev, "Couldn't get our SAT clock\n");
678		ret = PTR_ERR(backend->sat_clk);
679		goto err_assert_reset;
680	}
681
682	ret = clk_prepare_enable(backend->sat_clk);
683	if (ret) {
684		dev_err(dev, "Couldn't enable the SAT clock\n");
685		return ret;
686	}
687
688	return 0;
689
690err_assert_reset:
691	reset_control_assert(backend->sat_reset);
692	return ret;
693}
694
695static int sun4i_backend_free_sat(struct device *dev) {
696	struct sun4i_backend *backend = dev_get_drvdata(dev);
697
698	clk_disable_unprepare(backend->sat_clk);
699	reset_control_assert(backend->sat_reset);
700
701	return 0;
702}
703
704/*
705 * The display backend can take video output from the display frontend, or
706 * the display enhancement unit on the A80, as input for one it its layers.
707 * This relationship within the display pipeline is encoded in the device
708 * tree with of_graph, and we use it here to figure out which backend, if
709 * there are 2 or more, we are currently probing. The number would be in
710 * the "reg" property of the upstream output port endpoint.
711 */
712static int sun4i_backend_of_get_id(struct device_node *node)
713{
714	struct device_node *ep, *remote;
715	struct of_endpoint of_ep;
716
717	/* Input port is 0, and we want the first endpoint. */
718	ep = of_graph_get_endpoint_by_regs(node, 0, -1);
719	if (!ep)
720		return -EINVAL;
721
722	remote = of_graph_get_remote_endpoint(ep);
723	of_node_put(ep);
724	if (!remote)
725		return -EINVAL;
726
727	of_graph_parse_endpoint(remote, &of_ep);
728	of_node_put(remote);
729	return of_ep.id;
730}
731
732/* TODO: This needs to take multiple pipelines into account */
733static struct sun4i_frontend *sun4i_backend_find_frontend(struct sun4i_drv *drv,
734							  struct device_node *node)
735{
736	struct device_node *port, *ep, *remote;
737	struct sun4i_frontend *frontend;
738
739	port = of_graph_get_port_by_id(node, 0);
740	if (!port)
741		return ERR_PTR(-EINVAL);
742
743	for_each_available_child_of_node(port, ep) {
744		remote = of_graph_get_remote_port_parent(ep);
745		if (!remote)
746			continue;
747		of_node_put(remote);
748
749		/* does this node match any registered engines? */
750		list_for_each_entry(frontend, &drv->frontend_list, list) {
751			if (remote == frontend->node) {
752				of_node_put(port);
753				of_node_put(ep);
754				return frontend;
755			}
756		}
757	}
758	of_node_put(port);
759	return ERR_PTR(-EINVAL);
760}
761
762static const struct sunxi_engine_ops sun4i_backend_engine_ops = {
763	.atomic_begin			= sun4i_backend_atomic_begin,
764	.atomic_check			= sun4i_backend_atomic_check,
765	.commit				= sun4i_backend_commit,
766	.layers_init			= sun4i_layers_init,
767	.apply_color_correction		= sun4i_backend_apply_color_correction,
768	.disable_color_correction	= sun4i_backend_disable_color_correction,
769	.vblank_quirk			= sun4i_backend_vblank_quirk,
770};
771
772static const struct regmap_config sun4i_backend_regmap_config = {
773	.reg_bits	= 32,
774	.val_bits	= 32,
775	.reg_stride	= 4,
776	.max_register	= 0x5800,
777};
778
779static int sun4i_backend_bind(struct device *dev, struct device *master,
780			      void *data)
781{
782	struct platform_device *pdev = to_platform_device(dev);
783	struct drm_device *drm = data;
784	struct sun4i_drv *drv = drm->dev_private;
785	struct sun4i_backend *backend;
786	const struct sun4i_backend_quirks *quirks;
787	struct resource *res;
788	void __iomem *regs;
789	int i, ret;
790
791	backend = devm_kzalloc(dev, sizeof(*backend), GFP_KERNEL);
792	if (!backend)
793		return -ENOMEM;
794	dev_set_drvdata(dev, backend);
795	spin_lock_init(&backend->frontend_lock);
796
797	if (of_find_property(dev->of_node, "interconnects", NULL)) {
798		/*
799		 * This assume we have the same DMA constraints for all our the
800		 * devices in our pipeline (all the backends, but also the
801		 * frontends). This sounds bad, but it has always been the case
802		 * for us, and DRM doesn't do per-device allocation either, so
803		 * we would need to fix DRM first...
804		 */
805		ret = of_dma_configure(drm->dev, dev->of_node, true);
806		if (ret)
807			return ret;
808	} else {
809		/*
810		 * If we don't have the interconnect property, most likely
811		 * because of an old DT, we need to set the DMA offset by hand
812		 * on our device since the RAM mapping is at 0 for the DMA bus,
813		 * unlike the CPU.
814		 *
815		 * XXX(hch): this has no business in a driver and needs to move
816		 * to the device tree.
817		 *
818		 * If we have two subsequent calls to dma_direct_set_offset
819		 * returns -EINVAL. Unfortunately, this happens when we have two
820		 * backends in the system, and will result in the driver
821		 * reporting an error while it has been setup properly before.
822		 * Ignore EINVAL, but it should really be removed eventually.
823		 */
824		ret = dma_direct_set_offset(drm->dev, PHYS_OFFSET, 0, SZ_4G);
825		if (ret && ret != -EINVAL)
826			return ret;
827	}
828
829	backend->engine.node = dev->of_node;
830	backend->engine.ops = &sun4i_backend_engine_ops;
831	backend->engine.id = sun4i_backend_of_get_id(dev->of_node);
832	if (backend->engine.id < 0)
833		return backend->engine.id;
834
835	backend->frontend = sun4i_backend_find_frontend(drv, dev->of_node);
836	if (IS_ERR(backend->frontend))
837		dev_warn(dev, "Couldn't find matching frontend, frontend features disabled\n");
838
839	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
840	regs = devm_ioremap_resource(dev, res);
841	if (IS_ERR(regs))
842		return PTR_ERR(regs);
843
844	backend->reset = devm_reset_control_get(dev, NULL);
845	if (IS_ERR(backend->reset)) {
846		dev_err(dev, "Couldn't get our reset line\n");
847		return PTR_ERR(backend->reset);
848	}
849
850	ret = reset_control_deassert(backend->reset);
851	if (ret) {
852		dev_err(dev, "Couldn't deassert our reset line\n");
853		return ret;
854	}
855
856	backend->bus_clk = devm_clk_get(dev, "ahb");
857	if (IS_ERR(backend->bus_clk)) {
858		dev_err(dev, "Couldn't get the backend bus clock\n");
859		ret = PTR_ERR(backend->bus_clk);
860		goto err_assert_reset;
861	}
862	clk_prepare_enable(backend->bus_clk);
863
864	backend->mod_clk = devm_clk_get(dev, "mod");
865	if (IS_ERR(backend->mod_clk)) {
866		dev_err(dev, "Couldn't get the backend module clock\n");
867		ret = PTR_ERR(backend->mod_clk);
868		goto err_disable_bus_clk;
869	}
870
871	ret = clk_set_rate_exclusive(backend->mod_clk, 300000000);
872	if (ret) {
873		dev_err(dev, "Couldn't set the module clock frequency\n");
874		goto err_disable_bus_clk;
875	}
876
877	clk_prepare_enable(backend->mod_clk);
878
879	backend->ram_clk = devm_clk_get(dev, "ram");
880	if (IS_ERR(backend->ram_clk)) {
881		dev_err(dev, "Couldn't get the backend RAM clock\n");
882		ret = PTR_ERR(backend->ram_clk);
883		goto err_disable_mod_clk;
884	}
885	clk_prepare_enable(backend->ram_clk);
886
887	if (of_device_is_compatible(dev->of_node,
888				    "allwinner,sun8i-a33-display-backend")) {
889		ret = sun4i_backend_init_sat(dev);
890		if (ret) {
891			dev_err(dev, "Couldn't init SAT resources\n");
892			goto err_disable_ram_clk;
893		}
894	}
895
896	backend->engine.regs = devm_regmap_init_mmio(dev, regs,
897						     &sun4i_backend_regmap_config);
898	if (IS_ERR(backend->engine.regs)) {
899		dev_err(dev, "Couldn't create the backend regmap\n");
900		return PTR_ERR(backend->engine.regs);
901	}
902
903	list_add_tail(&backend->engine.list, &drv->engine_list);
904
905	/*
906	 * Many of the backend's layer configuration registers have
907	 * undefined default values. This poses a risk as we use
908	 * regmap_update_bits in some places, and don't overwrite
909	 * the whole register.
910	 *
911	 * Clear the registers here to have something predictable.
912	 */
913	for (i = 0x800; i < 0x1000; i += 4)
914		regmap_write(backend->engine.regs, i, 0);
915
916	/* Disable registers autoloading */
917	regmap_write(backend->engine.regs, SUN4I_BACKEND_REGBUFFCTL_REG,
918		     SUN4I_BACKEND_REGBUFFCTL_AUTOLOAD_DIS);
919
920	/* Enable the backend */
921	regmap_write(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
922		     SUN4I_BACKEND_MODCTL_DEBE_EN |
923		     SUN4I_BACKEND_MODCTL_START_CTL);
924
925	/* Set output selection if needed */
926	quirks = of_device_get_match_data(dev);
927	if (quirks->needs_output_muxing) {
928		/*
929		 * We assume there is no dynamic muxing of backends
930		 * and TCONs, so we select the backend with same ID.
931		 *
932		 * While dynamic selection might be interesting, since
933		 * the CRTC is tied to the TCON, while the layers are
934		 * tied to the backends, this means, we will need to
935		 * switch between groups of layers. There might not be
936		 * a way to represent this constraint in DRM.
937		 */
938		regmap_update_bits(backend->engine.regs,
939				   SUN4I_BACKEND_MODCTL_REG,
940				   SUN4I_BACKEND_MODCTL_OUT_SEL,
941				   (backend->engine.id
942				    ? SUN4I_BACKEND_MODCTL_OUT_LCD1
943				    : SUN4I_BACKEND_MODCTL_OUT_LCD0));
944	}
945
946	backend->quirks = quirks;
947
948	return 0;
949
950err_disable_ram_clk:
951	clk_disable_unprepare(backend->ram_clk);
952err_disable_mod_clk:
953	clk_rate_exclusive_put(backend->mod_clk);
954	clk_disable_unprepare(backend->mod_clk);
955err_disable_bus_clk:
956	clk_disable_unprepare(backend->bus_clk);
957err_assert_reset:
958	reset_control_assert(backend->reset);
959	return ret;
960}
961
962static void sun4i_backend_unbind(struct device *dev, struct device *master,
963				 void *data)
964{
965	struct sun4i_backend *backend = dev_get_drvdata(dev);
966
967	list_del(&backend->engine.list);
968
969	if (of_device_is_compatible(dev->of_node,
970				    "allwinner,sun8i-a33-display-backend"))
971		sun4i_backend_free_sat(dev);
972
973	clk_disable_unprepare(backend->ram_clk);
974	clk_rate_exclusive_put(backend->mod_clk);
975	clk_disable_unprepare(backend->mod_clk);
976	clk_disable_unprepare(backend->bus_clk);
977	reset_control_assert(backend->reset);
978}
979
980static const struct component_ops sun4i_backend_ops = {
981	.bind	= sun4i_backend_bind,
982	.unbind	= sun4i_backend_unbind,
983};
984
985static int sun4i_backend_probe(struct platform_device *pdev)
986{
987	return component_add(&pdev->dev, &sun4i_backend_ops);
988}
989
990static int sun4i_backend_remove(struct platform_device *pdev)
991{
992	component_del(&pdev->dev, &sun4i_backend_ops);
993
994	return 0;
995}
996
997static const struct sun4i_backend_quirks sun4i_backend_quirks = {
998	.needs_output_muxing = true,
999};
1000
1001static const struct sun4i_backend_quirks sun5i_backend_quirks = {
1002};
1003
1004static const struct sun4i_backend_quirks sun6i_backend_quirks = {
1005};
1006
1007static const struct sun4i_backend_quirks sun7i_backend_quirks = {
1008	.needs_output_muxing = true,
1009};
1010
1011static const struct sun4i_backend_quirks sun8i_a33_backend_quirks = {
1012	.supports_lowest_plane_alpha = true,
1013};
1014
1015static const struct sun4i_backend_quirks sun9i_backend_quirks = {
1016};
1017
1018static const struct of_device_id sun4i_backend_of_table[] = {
1019	{
1020		.compatible = "allwinner,sun4i-a10-display-backend",
1021		.data = &sun4i_backend_quirks,
1022	},
1023	{
1024		.compatible = "allwinner,sun5i-a13-display-backend",
1025		.data = &sun5i_backend_quirks,
1026	},
1027	{
1028		.compatible = "allwinner,sun6i-a31-display-backend",
1029		.data = &sun6i_backend_quirks,
1030	},
1031	{
1032		.compatible = "allwinner,sun7i-a20-display-backend",
1033		.data = &sun7i_backend_quirks,
1034	},
1035	{
1036		.compatible = "allwinner,sun8i-a23-display-backend",
1037		.data = &sun8i_a33_backend_quirks,
1038	},
1039	{
1040		.compatible = "allwinner,sun8i-a33-display-backend",
1041		.data = &sun8i_a33_backend_quirks,
1042	},
1043	{
1044		.compatible = "allwinner,sun9i-a80-display-backend",
1045		.data = &sun9i_backend_quirks,
1046	},
1047	{ }
1048};
1049MODULE_DEVICE_TABLE(of, sun4i_backend_of_table);
1050
1051static struct platform_driver sun4i_backend_platform_driver = {
1052	.probe		= sun4i_backend_probe,
1053	.remove		= sun4i_backend_remove,
1054	.driver		= {
1055		.name		= "sun4i-backend",
1056		.of_match_table	= sun4i_backend_of_table,
1057	},
1058};
1059module_platform_driver(sun4i_backend_platform_driver);
1060
1061MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
1062MODULE_DESCRIPTION("Allwinner A10 Display Backend Driver");
1063MODULE_LICENSE("GPL");
1064