xref: /linux/drivers/gpu/drm/mgag200/mgag200_mode.c (revision 001821b0e79716c4e17c71d8e053a23599a7a508)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2010 Matt Turner.
4  * Copyright 2012 Red Hat
5  *
6  * Authors: Matthew Garrett
7  *	    Matt Turner
8  *	    Dave Airlie
9  */
10 
11 #include <linux/delay.h>
12 #include <linux/iosys-map.h>
13 
14 #include <drm/drm_atomic.h>
15 #include <drm/drm_atomic_helper.h>
16 #include <drm/drm_cache.h>
17 #include <drm/drm_damage_helper.h>
18 #include <drm/drm_edid.h>
19 #include <drm/drm_format_helper.h>
20 #include <drm/drm_fourcc.h>
21 #include <drm/drm_framebuffer.h>
22 #include <drm/drm_gem_atomic_helper.h>
23 #include <drm/drm_gem_framebuffer_helper.h>
24 #include <drm/drm_panic.h>
25 #include <drm/drm_print.h>
26 
27 #include "mgag200_drv.h"
28 
29 /*
30  * This file contains setup code for the CRTC.
31  */
32 
33 void mgag200_crtc_set_gamma_linear(struct mga_device *mdev,
34 				   const struct drm_format_info *format)
35 {
36 	int i;
37 
38 	WREG8(DAC_INDEX + MGA1064_INDEX, 0);
39 
40 	switch (format->format) {
41 	case DRM_FORMAT_RGB565:
42 		/* Use better interpolation, to take 32 values from 0 to 255 */
43 		for (i = 0; i < MGAG200_LUT_SIZE / 8; i++) {
44 			WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 8 + i / 4);
45 			WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 4 + i / 16);
46 			WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 8 + i / 4);
47 		}
48 		/* Green has one more bit, so add padding with 0 for red and blue. */
49 		for (i = MGAG200_LUT_SIZE / 8; i < MGAG200_LUT_SIZE / 4; i++) {
50 			WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
51 			WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 4 + i / 16);
52 			WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
53 		}
54 		break;
55 	case DRM_FORMAT_RGB888:
56 	case DRM_FORMAT_XRGB8888:
57 		for (i = 0; i < MGAG200_LUT_SIZE; i++) {
58 			WREG8(DAC_INDEX + MGA1064_COL_PAL, i);
59 			WREG8(DAC_INDEX + MGA1064_COL_PAL, i);
60 			WREG8(DAC_INDEX + MGA1064_COL_PAL, i);
61 		}
62 		break;
63 	default:
64 		drm_warn_once(&mdev->base, "Unsupported format %p4cc for gamma correction\n",
65 			      &format->format);
66 		break;
67 	}
68 }
69 
70 void mgag200_crtc_set_gamma(struct mga_device *mdev,
71 			    const struct drm_format_info *format,
72 			    struct drm_color_lut *lut)
73 {
74 	int i;
75 
76 	WREG8(DAC_INDEX + MGA1064_INDEX, 0);
77 
78 	switch (format->format) {
79 	case DRM_FORMAT_RGB565:
80 		/* Use better interpolation, to take 32 values from lut[0] to lut[255] */
81 		for (i = 0; i < MGAG200_LUT_SIZE / 8; i++) {
82 			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 8 + i / 4].red >> 8);
83 			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 4 + i / 16].green >> 8);
84 			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 8 + i / 4].blue >> 8);
85 		}
86 		/* Green has one more bit, so add padding with 0 for red and blue. */
87 		for (i = MGAG200_LUT_SIZE / 8; i < MGAG200_LUT_SIZE / 4; i++) {
88 			WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
89 			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 4 + i / 16].green >> 8);
90 			WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
91 		}
92 		break;
93 	case DRM_FORMAT_RGB888:
94 	case DRM_FORMAT_XRGB8888:
95 		for (i = 0; i < MGAG200_LUT_SIZE; i++) {
96 			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i].red >> 8);
97 			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i].green >> 8);
98 			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i].blue >> 8);
99 		}
100 		break;
101 	default:
102 		drm_warn_once(&mdev->base, "Unsupported format %p4cc for gamma correction\n",
103 			      &format->format);
104 		break;
105 	}
106 }
107 
108 static inline void mga_wait_vsync(struct mga_device *mdev)
109 {
110 	unsigned long timeout = jiffies + HZ/10;
111 	unsigned int status = 0;
112 
113 	do {
114 		status = RREG32(MGAREG_Status);
115 	} while ((status & 0x08) && time_before(jiffies, timeout));
116 	timeout = jiffies + HZ/10;
117 	status = 0;
118 	do {
119 		status = RREG32(MGAREG_Status);
120 	} while (!(status & 0x08) && time_before(jiffies, timeout));
121 }
122 
123 static inline void mga_wait_busy(struct mga_device *mdev)
124 {
125 	unsigned long timeout = jiffies + HZ;
126 	unsigned int status = 0;
127 	do {
128 		status = RREG8(MGAREG_Status + 2);
129 	} while ((status & 0x01) && time_before(jiffies, timeout));
130 }
131 
132 /*
133  * This is how the framebuffer base address is stored in g200 cards:
134  *   * Assume @offset is the gpu_addr variable of the framebuffer object
135  *   * Then addr is the number of _pixels_ (not bytes) from the start of
136  *     VRAM to the first pixel we want to display. (divided by 2 for 32bit
137  *     framebuffers)
138  *   * addr is stored in the CRTCEXT0, CRTCC and CRTCD registers
139  *      addr<20> -> CRTCEXT0<6>
140  *      addr<19-16> -> CRTCEXT0<3-0>
141  *      addr<15-8> -> CRTCC<7-0>
142  *      addr<7-0> -> CRTCD<7-0>
143  *
144  *  CRTCEXT0 has to be programmed last to trigger an update and make the
145  *  new addr variable take effect.
146  */
147 static void mgag200_set_startadd(struct mga_device *mdev,
148 				 unsigned long offset)
149 {
150 	struct drm_device *dev = &mdev->base;
151 	u32 startadd;
152 	u8 crtcc, crtcd, crtcext0;
153 
154 	startadd = offset / 8;
155 
156 	if (startadd > 0)
157 		drm_WARN_ON_ONCE(dev, mdev->info->bug_no_startadd);
158 
159 	/*
160 	 * Can't store addresses any higher than that, but we also
161 	 * don't have more than 16 MiB of memory, so it should be fine.
162 	 */
163 	drm_WARN_ON(dev, startadd > 0x1fffff);
164 
165 	RREG_ECRT(0x00, crtcext0);
166 
167 	crtcc = (startadd >> 8) & 0xff;
168 	crtcd = startadd & 0xff;
169 	crtcext0 &= 0xb0;
170 	crtcext0 |= ((startadd >> 14) & BIT(6)) |
171 		    ((startadd >> 16) & 0x0f);
172 
173 	WREG_CRT(0x0c, crtcc);
174 	WREG_CRT(0x0d, crtcd);
175 	WREG_ECRT(0x00, crtcext0);
176 }
177 
178 void mgag200_init_registers(struct mga_device *mdev)
179 {
180 	u8 crtc11, misc;
181 
182 	WREG_SEQ(2, 0x0f);
183 	WREG_SEQ(3, 0x00);
184 	WREG_SEQ(4, 0x0e);
185 
186 	WREG_CRT(10, 0);
187 	WREG_CRT(11, 0);
188 	WREG_CRT(12, 0);
189 	WREG_CRT(13, 0);
190 	WREG_CRT(14, 0);
191 	WREG_CRT(15, 0);
192 
193 	RREG_CRT(0x11, crtc11);
194 	crtc11 &= ~(MGAREG_CRTC11_CRTCPROTECT |
195 		    MGAREG_CRTC11_VINTEN |
196 		    MGAREG_CRTC11_VINTCLR);
197 	WREG_CRT(0x11, crtc11);
198 
199 	misc = RREG8(MGA_MISC_IN);
200 	misc |= MGAREG_MISC_IOADSEL;
201 	WREG8(MGA_MISC_OUT, misc);
202 }
203 
204 void mgag200_set_mode_regs(struct mga_device *mdev, const struct drm_display_mode *mode)
205 {
206 	const struct mgag200_device_info *info = mdev->info;
207 	unsigned int hdisplay, hsyncstart, hsyncend, htotal;
208 	unsigned int vdisplay, vsyncstart, vsyncend, vtotal;
209 	u8 misc, crtcext1, crtcext2, crtcext5;
210 
211 	hdisplay = mode->hdisplay / 8 - 1;
212 	hsyncstart = mode->hsync_start / 8 - 1;
213 	hsyncend = mode->hsync_end / 8 - 1;
214 	htotal = mode->htotal / 8 - 1;
215 
216 	/* Work around hardware quirk */
217 	if ((htotal & 0x07) == 0x06 || (htotal & 0x07) == 0x04)
218 		htotal++;
219 
220 	vdisplay = mode->vdisplay - 1;
221 	vsyncstart = mode->vsync_start - 1;
222 	vsyncend = mode->vsync_end - 1;
223 	vtotal = mode->vtotal - 2;
224 
225 	misc = RREG8(MGA_MISC_IN);
226 
227 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
228 		misc |= MGAREG_MISC_HSYNCPOL;
229 	else
230 		misc &= ~MGAREG_MISC_HSYNCPOL;
231 
232 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
233 		misc |= MGAREG_MISC_VSYNCPOL;
234 	else
235 		misc &= ~MGAREG_MISC_VSYNCPOL;
236 
237 	crtcext1 = (((htotal - 4) & 0x100) >> 8) |
238 		   ((hdisplay & 0x100) >> 7) |
239 		   ((hsyncstart & 0x100) >> 6) |
240 		    (htotal & 0x40);
241 	if (info->has_vidrst)
242 		crtcext1 |= MGAREG_CRTCEXT1_VRSTEN |
243 			    MGAREG_CRTCEXT1_HRSTEN;
244 
245 	crtcext2 = ((vtotal & 0xc00) >> 10) |
246 		   ((vdisplay & 0x400) >> 8) |
247 		   ((vdisplay & 0xc00) >> 7) |
248 		   ((vsyncstart & 0xc00) >> 5) |
249 		   ((vdisplay & 0x400) >> 3);
250 	crtcext5 = 0x00;
251 
252 	WREG_CRT(0, htotal - 4);
253 	WREG_CRT(1, hdisplay);
254 	WREG_CRT(2, hdisplay);
255 	WREG_CRT(3, (htotal & 0x1F) | 0x80);
256 	WREG_CRT(4, hsyncstart);
257 	WREG_CRT(5, ((htotal & 0x20) << 2) | (hsyncend & 0x1F));
258 	WREG_CRT(6, vtotal & 0xFF);
259 	WREG_CRT(7, ((vtotal & 0x100) >> 8) |
260 		 ((vdisplay & 0x100) >> 7) |
261 		 ((vsyncstart & 0x100) >> 6) |
262 		 ((vdisplay & 0x100) >> 5) |
263 		 ((vdisplay & 0x100) >> 4) | /* linecomp */
264 		 ((vtotal & 0x200) >> 4) |
265 		 ((vdisplay & 0x200) >> 3) |
266 		 ((vsyncstart & 0x200) >> 2));
267 	WREG_CRT(9, ((vdisplay & 0x200) >> 4) |
268 		 ((vdisplay & 0x200) >> 3));
269 	WREG_CRT(16, vsyncstart & 0xFF);
270 	WREG_CRT(17, (vsyncend & 0x0F) | 0x20);
271 	WREG_CRT(18, vdisplay & 0xFF);
272 	WREG_CRT(20, 0);
273 	WREG_CRT(21, vdisplay & 0xFF);
274 	WREG_CRT(22, (vtotal + 1) & 0xFF);
275 	WREG_CRT(23, 0xc3);
276 	WREG_CRT(24, vdisplay & 0xFF);
277 
278 	WREG_ECRT(0x01, crtcext1);
279 	WREG_ECRT(0x02, crtcext2);
280 	WREG_ECRT(0x05, crtcext5);
281 
282 	WREG8(MGA_MISC_OUT, misc);
283 }
284 
285 static u8 mgag200_get_bpp_shift(const struct drm_format_info *format)
286 {
287 	static const u8 bpp_shift[] = {0, 1, 0, 2};
288 
289 	return bpp_shift[format->cpp[0] - 1];
290 }
291 
292 /*
293  * Calculates the HW offset value from the framebuffer's pitch. The
294  * offset is a multiple of the pixel size and depends on the display
295  * format.
296  */
297 static u32 mgag200_calculate_offset(struct mga_device *mdev,
298 				    const struct drm_framebuffer *fb)
299 {
300 	u32 offset = fb->pitches[0] / fb->format->cpp[0];
301 	u8 bppshift = mgag200_get_bpp_shift(fb->format);
302 
303 	if (fb->format->cpp[0] * 8 == 24)
304 		offset = (offset * 3) >> (4 - bppshift);
305 	else
306 		offset = offset >> (4 - bppshift);
307 
308 	return offset;
309 }
310 
311 static void mgag200_set_offset(struct mga_device *mdev,
312 			       const struct drm_framebuffer *fb)
313 {
314 	u8 crtc13, crtcext0;
315 	u32 offset = mgag200_calculate_offset(mdev, fb);
316 
317 	RREG_ECRT(0, crtcext0);
318 
319 	crtc13 = offset & 0xff;
320 
321 	crtcext0 &= ~MGAREG_CRTCEXT0_OFFSET_MASK;
322 	crtcext0 |= (offset >> 4) & MGAREG_CRTCEXT0_OFFSET_MASK;
323 
324 	WREG_CRT(0x13, crtc13);
325 	WREG_ECRT(0x00, crtcext0);
326 }
327 
328 void mgag200_set_format_regs(struct mga_device *mdev, const struct drm_format_info *format)
329 {
330 	struct drm_device *dev = &mdev->base;
331 	unsigned int bpp, bppshift, scale;
332 	u8 crtcext3, xmulctrl;
333 
334 	bpp = format->cpp[0] * 8;
335 
336 	bppshift = mgag200_get_bpp_shift(format);
337 	switch (bpp) {
338 	case 24:
339 		scale = ((1 << bppshift) * 3) - 1;
340 		break;
341 	default:
342 		scale = (1 << bppshift) - 1;
343 		break;
344 	}
345 
346 	RREG_ECRT(3, crtcext3);
347 
348 	switch (bpp) {
349 	case 8:
350 		xmulctrl = MGA1064_MUL_CTL_8bits;
351 		break;
352 	case 16:
353 		if (format->depth == 15)
354 			xmulctrl = MGA1064_MUL_CTL_15bits;
355 		else
356 			xmulctrl = MGA1064_MUL_CTL_16bits;
357 		break;
358 	case 24:
359 		xmulctrl = MGA1064_MUL_CTL_24bits;
360 		break;
361 	case 32:
362 		xmulctrl = MGA1064_MUL_CTL_32_24bits;
363 		break;
364 	default:
365 		/* BUG: We should have caught this problem already. */
366 		drm_WARN_ON(dev, "invalid format depth\n");
367 		return;
368 	}
369 
370 	crtcext3 &= ~GENMASK(2, 0);
371 	crtcext3 |= scale;
372 
373 	WREG_DAC(MGA1064_MUL_CTL, xmulctrl);
374 
375 	WREG_GFX(0, 0x00);
376 	WREG_GFX(1, 0x00);
377 	WREG_GFX(2, 0x00);
378 	WREG_GFX(3, 0x00);
379 	WREG_GFX(4, 0x00);
380 	WREG_GFX(5, 0x40);
381 	/* GCTL6 should be 0x05, but we configure memmapsl to 0xb8000 (text mode),
382 	 * so that it doesn't hang when running kexec/kdump on G200_SE rev42.
383 	 */
384 	WREG_GFX(6, 0x0d);
385 	WREG_GFX(7, 0x0f);
386 	WREG_GFX(8, 0x0f);
387 
388 	WREG_ECRT(3, crtcext3);
389 }
390 
391 void mgag200_enable_display(struct mga_device *mdev)
392 {
393 	u8 seq0, crtcext1;
394 
395 	RREG_SEQ(0x00, seq0);
396 	seq0 |= MGAREG_SEQ0_SYNCRST |
397 		MGAREG_SEQ0_ASYNCRST;
398 	WREG_SEQ(0x00, seq0);
399 
400 	/*
401 	 * TODO: replace busy waiting with vblank IRQ; put
402 	 *       msleep(50) before changing SCROFF
403 	 */
404 	mga_wait_vsync(mdev);
405 	mga_wait_busy(mdev);
406 
407 	RREG_ECRT(0x01, crtcext1);
408 	crtcext1 &= ~MGAREG_CRTCEXT1_VSYNCOFF;
409 	crtcext1 &= ~MGAREG_CRTCEXT1_HSYNCOFF;
410 	WREG_ECRT(0x01, crtcext1);
411 }
412 
413 static void mgag200_disable_display(struct mga_device *mdev)
414 {
415 	u8 seq0, crtcext1;
416 
417 	RREG_SEQ(0x00, seq0);
418 	seq0 &= ~MGAREG_SEQ0_SYNCRST;
419 	WREG_SEQ(0x00, seq0);
420 
421 	/*
422 	 * TODO: replace busy waiting with vblank IRQ; put
423 	 *       msleep(50) before changing SCROFF
424 	 */
425 	mga_wait_vsync(mdev);
426 	mga_wait_busy(mdev);
427 
428 	RREG_ECRT(0x01, crtcext1);
429 	crtcext1 |= MGAREG_CRTCEXT1_VSYNCOFF |
430 		    MGAREG_CRTCEXT1_HSYNCOFF;
431 	WREG_ECRT(0x01, crtcext1);
432 }
433 
434 static void mgag200_handle_damage(struct mga_device *mdev, const struct iosys_map *vmap,
435 				  struct drm_framebuffer *fb, struct drm_rect *clip)
436 {
437 	struct iosys_map dst = IOSYS_MAP_INIT_VADDR_IOMEM(mdev->vram);
438 
439 	iosys_map_incr(&dst, drm_fb_clip_offset(fb->pitches[0], fb->format, clip));
440 	drm_fb_memcpy(&dst, fb->pitches, vmap, fb, clip);
441 
442 	/* Flushing the cache greatly improves latency on x86_64 */
443 #if defined(CONFIG_DRM_MGAG200_IOBURST_WORKAROUND)
444 	if (!vmap->is_iomem)
445 		drm_clflush_virt_range(vmap->vaddr + clip->y1 * fb->pitches[0],
446 				       drm_rect_height(clip) * fb->pitches[0]);
447 #endif
448 }
449 
450 /*
451  * Primary plane
452  */
453 
454 const uint32_t mgag200_primary_plane_formats[] = {
455 	DRM_FORMAT_XRGB8888,
456 	DRM_FORMAT_RGB565,
457 	DRM_FORMAT_RGB888,
458 };
459 
460 const size_t mgag200_primary_plane_formats_size = ARRAY_SIZE(mgag200_primary_plane_formats);
461 
462 const uint64_t mgag200_primary_plane_fmtmods[] = {
463 	DRM_FORMAT_MOD_LINEAR,
464 	DRM_FORMAT_MOD_INVALID
465 };
466 
467 int mgag200_primary_plane_helper_atomic_check(struct drm_plane *plane,
468 					      struct drm_atomic_state *new_state)
469 {
470 	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(new_state, plane);
471 	struct drm_framebuffer *new_fb = new_plane_state->fb;
472 	struct drm_framebuffer *fb = NULL;
473 	struct drm_crtc *new_crtc = new_plane_state->crtc;
474 	struct drm_crtc_state *new_crtc_state = NULL;
475 	struct mgag200_crtc_state *new_mgag200_crtc_state;
476 	int ret;
477 
478 	if (new_crtc)
479 		new_crtc_state = drm_atomic_get_new_crtc_state(new_state, new_crtc);
480 
481 	ret = drm_atomic_helper_check_plane_state(new_plane_state, new_crtc_state,
482 						  DRM_PLANE_NO_SCALING,
483 						  DRM_PLANE_NO_SCALING,
484 						  false, true);
485 	if (ret)
486 		return ret;
487 	else if (!new_plane_state->visible)
488 		return 0;
489 
490 	if (plane->state)
491 		fb = plane->state->fb;
492 
493 	if (!fb || (fb->format != new_fb->format))
494 		new_crtc_state->mode_changed = true; /* update PLL settings */
495 
496 	new_mgag200_crtc_state = to_mgag200_crtc_state(new_crtc_state);
497 	new_mgag200_crtc_state->format = new_fb->format;
498 
499 	return 0;
500 }
501 
502 void mgag200_primary_plane_helper_atomic_update(struct drm_plane *plane,
503 						struct drm_atomic_state *old_state)
504 {
505 	struct drm_device *dev = plane->dev;
506 	struct mga_device *mdev = to_mga_device(dev);
507 	struct drm_plane_state *plane_state = plane->state;
508 	struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(old_state, plane);
509 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
510 	struct drm_framebuffer *fb = plane_state->fb;
511 	struct drm_atomic_helper_damage_iter iter;
512 	struct drm_rect damage;
513 
514 	drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
515 	drm_atomic_for_each_plane_damage(&iter, &damage) {
516 		mgag200_handle_damage(mdev, shadow_plane_state->data, fb, &damage);
517 	}
518 
519 	/* Always scanout image at VRAM offset 0 */
520 	mgag200_set_startadd(mdev, (u32)0);
521 	mgag200_set_offset(mdev, fb);
522 }
523 
524 void mgag200_primary_plane_helper_atomic_enable(struct drm_plane *plane,
525 						struct drm_atomic_state *state)
526 {
527 	struct drm_device *dev = plane->dev;
528 	struct mga_device *mdev = to_mga_device(dev);
529 	u8 seq1;
530 
531 	RREG_SEQ(0x01, seq1);
532 	seq1 &= ~MGAREG_SEQ1_SCROFF;
533 	WREG_SEQ(0x01, seq1);
534 	msleep(20);
535 }
536 
537 void mgag200_primary_plane_helper_atomic_disable(struct drm_plane *plane,
538 						 struct drm_atomic_state *old_state)
539 {
540 	struct drm_device *dev = plane->dev;
541 	struct mga_device *mdev = to_mga_device(dev);
542 	u8 seq1;
543 
544 	RREG_SEQ(0x01, seq1);
545 	seq1 |= MGAREG_SEQ1_SCROFF;
546 	WREG_SEQ(0x01, seq1);
547 	msleep(20);
548 }
549 
550 int mgag200_primary_plane_helper_get_scanout_buffer(struct drm_plane *plane,
551 						    struct drm_scanout_buffer *sb)
552 {
553 	struct mga_device *mdev = to_mga_device(plane->dev);
554 	struct iosys_map map = IOSYS_MAP_INIT_VADDR_IOMEM(mdev->vram);
555 
556 	if (plane->state && plane->state->fb) {
557 		sb->format = plane->state->fb->format;
558 		sb->width = plane->state->fb->width;
559 		sb->height = plane->state->fb->height;
560 		sb->pitch[0] = plane->state->fb->pitches[0];
561 		sb->map[0] = map;
562 		return 0;
563 	}
564 	return -ENODEV;
565 }
566 
567 /*
568  * CRTC
569  */
570 
571 enum drm_mode_status mgag200_crtc_helper_mode_valid(struct drm_crtc *crtc,
572 						    const struct drm_display_mode *mode)
573 {
574 	struct mga_device *mdev = to_mga_device(crtc->dev);
575 	const struct mgag200_device_info *info = mdev->info;
576 
577 	/*
578 	 * Some devices have additional limits on the size of the
579 	 * display mode.
580 	 */
581 	if (mode->hdisplay > info->max_hdisplay)
582 		return MODE_VIRTUAL_X;
583 	if (mode->vdisplay > info->max_vdisplay)
584 		return MODE_VIRTUAL_Y;
585 
586 	if ((mode->hdisplay % 8) != 0 || (mode->hsync_start % 8) != 0 ||
587 	    (mode->hsync_end % 8) != 0 || (mode->htotal % 8) != 0) {
588 		return MODE_H_ILLEGAL;
589 	}
590 
591 	if (mode->crtc_hdisplay > 2048 || mode->crtc_hsync_start > 4096 ||
592 	    mode->crtc_hsync_end > 4096 || mode->crtc_htotal > 4096 ||
593 	    mode->crtc_vdisplay > 2048 || mode->crtc_vsync_start > 4096 ||
594 	    mode->crtc_vsync_end > 4096 || mode->crtc_vtotal > 4096) {
595 		return MODE_BAD;
596 	}
597 
598 	return MODE_OK;
599 }
600 
601 int mgag200_crtc_helper_atomic_check(struct drm_crtc *crtc, struct drm_atomic_state *new_state)
602 {
603 	struct drm_device *dev = crtc->dev;
604 	struct mga_device *mdev = to_mga_device(dev);
605 	const struct mgag200_device_funcs *funcs = mdev->funcs;
606 	struct drm_crtc_state *new_crtc_state = drm_atomic_get_new_crtc_state(new_state, crtc);
607 	struct drm_property_blob *new_gamma_lut = new_crtc_state->gamma_lut;
608 	int ret;
609 
610 	if (!new_crtc_state->enable)
611 		return 0;
612 
613 	ret = drm_atomic_helper_check_crtc_primary_plane(new_crtc_state);
614 	if (ret)
615 		return ret;
616 
617 	if (new_crtc_state->mode_changed) {
618 		if (funcs->pixpllc_atomic_check) {
619 			ret = funcs->pixpllc_atomic_check(crtc, new_state);
620 			if (ret)
621 				return ret;
622 		}
623 	}
624 
625 	if (new_crtc_state->color_mgmt_changed && new_gamma_lut) {
626 		if (new_gamma_lut->length != MGAG200_LUT_SIZE * sizeof(struct drm_color_lut)) {
627 			drm_dbg(dev, "Wrong size for gamma_lut %zu\n", new_gamma_lut->length);
628 			return -EINVAL;
629 		}
630 	}
631 
632 	return 0;
633 }
634 
635 void mgag200_crtc_helper_atomic_flush(struct drm_crtc *crtc, struct drm_atomic_state *old_state)
636 {
637 	struct drm_crtc_state *crtc_state = crtc->state;
638 	struct mgag200_crtc_state *mgag200_crtc_state = to_mgag200_crtc_state(crtc_state);
639 	struct drm_device *dev = crtc->dev;
640 	struct mga_device *mdev = to_mga_device(dev);
641 
642 	if (crtc_state->enable && crtc_state->color_mgmt_changed) {
643 		const struct drm_format_info *format = mgag200_crtc_state->format;
644 
645 		if (crtc_state->gamma_lut)
646 			mgag200_crtc_set_gamma(mdev, format, crtc_state->gamma_lut->data);
647 		else
648 			mgag200_crtc_set_gamma_linear(mdev, format);
649 	}
650 }
651 
652 void mgag200_crtc_helper_atomic_enable(struct drm_crtc *crtc, struct drm_atomic_state *old_state)
653 {
654 	struct drm_device *dev = crtc->dev;
655 	struct mga_device *mdev = to_mga_device(dev);
656 	const struct mgag200_device_funcs *funcs = mdev->funcs;
657 	struct drm_crtc_state *crtc_state = crtc->state;
658 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
659 	struct mgag200_crtc_state *mgag200_crtc_state = to_mgag200_crtc_state(crtc_state);
660 	const struct drm_format_info *format = mgag200_crtc_state->format;
661 
662 	if (funcs->disable_vidrst)
663 		funcs->disable_vidrst(mdev);
664 
665 	mgag200_set_format_regs(mdev, format);
666 	mgag200_set_mode_regs(mdev, adjusted_mode);
667 
668 	if (funcs->pixpllc_atomic_update)
669 		funcs->pixpllc_atomic_update(crtc, old_state);
670 
671 	if (crtc_state->gamma_lut)
672 		mgag200_crtc_set_gamma(mdev, format, crtc_state->gamma_lut->data);
673 	else
674 		mgag200_crtc_set_gamma_linear(mdev, format);
675 
676 	mgag200_enable_display(mdev);
677 
678 	if (funcs->enable_vidrst)
679 		funcs->enable_vidrst(mdev);
680 }
681 
682 void mgag200_crtc_helper_atomic_disable(struct drm_crtc *crtc, struct drm_atomic_state *old_state)
683 {
684 	struct mga_device *mdev = to_mga_device(crtc->dev);
685 	const struct mgag200_device_funcs *funcs = mdev->funcs;
686 
687 	if (funcs->disable_vidrst)
688 		funcs->disable_vidrst(mdev);
689 
690 	mgag200_disable_display(mdev);
691 
692 	if (funcs->enable_vidrst)
693 		funcs->enable_vidrst(mdev);
694 }
695 
696 void mgag200_crtc_reset(struct drm_crtc *crtc)
697 {
698 	struct mgag200_crtc_state *mgag200_crtc_state;
699 
700 	if (crtc->state)
701 		crtc->funcs->atomic_destroy_state(crtc, crtc->state);
702 
703 	mgag200_crtc_state = kzalloc(sizeof(*mgag200_crtc_state), GFP_KERNEL);
704 	if (mgag200_crtc_state)
705 		__drm_atomic_helper_crtc_reset(crtc, &mgag200_crtc_state->base);
706 	else
707 		__drm_atomic_helper_crtc_reset(crtc, NULL);
708 }
709 
710 struct drm_crtc_state *mgag200_crtc_atomic_duplicate_state(struct drm_crtc *crtc)
711 {
712 	struct drm_crtc_state *crtc_state = crtc->state;
713 	struct mgag200_crtc_state *mgag200_crtc_state = to_mgag200_crtc_state(crtc_state);
714 	struct mgag200_crtc_state *new_mgag200_crtc_state;
715 
716 	if (!crtc_state)
717 		return NULL;
718 
719 	new_mgag200_crtc_state = kzalloc(sizeof(*new_mgag200_crtc_state), GFP_KERNEL);
720 	if (!new_mgag200_crtc_state)
721 		return NULL;
722 	__drm_atomic_helper_crtc_duplicate_state(crtc, &new_mgag200_crtc_state->base);
723 
724 	new_mgag200_crtc_state->format = mgag200_crtc_state->format;
725 	memcpy(&new_mgag200_crtc_state->pixpllc, &mgag200_crtc_state->pixpllc,
726 	       sizeof(new_mgag200_crtc_state->pixpllc));
727 
728 	return &new_mgag200_crtc_state->base;
729 }
730 
731 void mgag200_crtc_atomic_destroy_state(struct drm_crtc *crtc, struct drm_crtc_state *crtc_state)
732 {
733 	struct mgag200_crtc_state *mgag200_crtc_state = to_mgag200_crtc_state(crtc_state);
734 
735 	__drm_atomic_helper_crtc_destroy_state(&mgag200_crtc_state->base);
736 	kfree(mgag200_crtc_state);
737 }
738 
739 /*
740  * Connector
741  */
742 
743 int mgag200_vga_connector_helper_get_modes(struct drm_connector *connector)
744 {
745 	struct mga_device *mdev = to_mga_device(connector->dev);
746 	const struct drm_edid *drm_edid;
747 	int count;
748 
749 	/*
750 	 * Protect access to I/O registers from concurrent modesetting
751 	 * by acquiring the I/O-register lock.
752 	 */
753 	mutex_lock(&mdev->rmmio_lock);
754 
755 	drm_edid = drm_edid_read(connector);
756 	drm_edid_connector_update(connector, drm_edid);
757 	count = drm_edid_connector_add_modes(connector);
758 	drm_edid_free(drm_edid);
759 
760 	mutex_unlock(&mdev->rmmio_lock);
761 
762 	return count;
763 }
764 
765 /*
766  * Mode config
767  */
768 
769 static void mgag200_mode_config_helper_atomic_commit_tail(struct drm_atomic_state *state)
770 {
771 	struct mga_device *mdev = to_mga_device(state->dev);
772 
773 	/*
774 	 * Concurrent operations could possibly trigger a call to
775 	 * drm_connector_helper_funcs.get_modes by trying to read the
776 	 * display modes. Protect access to I/O registers by acquiring
777 	 * the I/O-register lock.
778 	 */
779 	mutex_lock(&mdev->rmmio_lock);
780 	drm_atomic_helper_commit_tail(state);
781 	mutex_unlock(&mdev->rmmio_lock);
782 }
783 
784 static const struct drm_mode_config_helper_funcs mgag200_mode_config_helper_funcs = {
785 	.atomic_commit_tail = mgag200_mode_config_helper_atomic_commit_tail,
786 };
787 
788 /* Calculates a mode's required memory bandwidth (in KiB/sec). */
789 static uint32_t mgag200_calculate_mode_bandwidth(const struct drm_display_mode *mode,
790 						 unsigned int bits_per_pixel)
791 {
792 	uint32_t total_area, divisor;
793 	uint64_t active_area, pixels_per_second, bandwidth;
794 	uint64_t bytes_per_pixel = (bits_per_pixel + 7) / 8;
795 
796 	divisor = 1024;
797 
798 	if (!mode->htotal || !mode->vtotal || !mode->clock)
799 		return 0;
800 
801 	active_area = mode->hdisplay * mode->vdisplay;
802 	total_area = mode->htotal * mode->vtotal;
803 
804 	pixels_per_second = active_area * mode->clock * 1000;
805 	do_div(pixels_per_second, total_area);
806 
807 	bandwidth = pixels_per_second * bytes_per_pixel * 100;
808 	do_div(bandwidth, divisor);
809 
810 	return (uint32_t)bandwidth;
811 }
812 
813 static enum drm_mode_status mgag200_mode_config_mode_valid(struct drm_device *dev,
814 							   const struct drm_display_mode *mode)
815 {
816 	static const unsigned int max_bpp = 4; // DRM_FORMAT_XRGB8888
817 	struct mga_device *mdev = to_mga_device(dev);
818 	unsigned long fbsize, fbpages, max_fbpages;
819 	const struct mgag200_device_info *info = mdev->info;
820 
821 	max_fbpages = mdev->vram_available >> PAGE_SHIFT;
822 
823 	fbsize = mode->hdisplay * mode->vdisplay * max_bpp;
824 	fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE);
825 
826 	if (fbpages > max_fbpages)
827 		return MODE_MEM;
828 
829 	/*
830 	 * Test the mode's required memory bandwidth if the device
831 	 * specifies a maximum. Not all devices do though.
832 	 */
833 	if (info->max_mem_bandwidth) {
834 		uint32_t mode_bandwidth = mgag200_calculate_mode_bandwidth(mode, max_bpp * 8);
835 
836 		if (mode_bandwidth > (info->max_mem_bandwidth * 1024))
837 			return MODE_BAD;
838 	}
839 
840 	return MODE_OK;
841 }
842 
843 static const struct drm_mode_config_funcs mgag200_mode_config_funcs = {
844 	.fb_create = drm_gem_fb_create_with_dirty,
845 	.mode_valid = mgag200_mode_config_mode_valid,
846 	.atomic_check = drm_atomic_helper_check,
847 	.atomic_commit = drm_atomic_helper_commit,
848 };
849 
850 int mgag200_mode_config_init(struct mga_device *mdev, resource_size_t vram_available)
851 {
852 	struct drm_device *dev = &mdev->base;
853 	int ret;
854 
855 	mdev->vram_available = vram_available;
856 
857 	ret = drmm_mode_config_init(dev);
858 	if (ret) {
859 		drm_err(dev, "drmm_mode_config_init() failed: %d\n", ret);
860 		return ret;
861 	}
862 
863 	dev->mode_config.max_width = MGAG200_MAX_FB_WIDTH;
864 	dev->mode_config.max_height = MGAG200_MAX_FB_HEIGHT;
865 	dev->mode_config.preferred_depth = 24;
866 	dev->mode_config.funcs = &mgag200_mode_config_funcs;
867 	dev->mode_config.helper_private = &mgag200_mode_config_helper_funcs;
868 
869 	return 0;
870 }
871