1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2012 Red Hat
4 *
5 * based in parts on udlfb.c:
6 * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
7 * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
8 * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
9 */
10
11#include <linux/bitfield.h>
12
13#include <drm/drm_atomic.h>
14#include <drm/drm_atomic_helper.h>
15#include <drm/drm_crtc_helper.h>
16#include <drm/drm_damage_helper.h>
17#include <drm/drm_drv.h>
18#include <drm/drm_edid.h>
19#include <drm/drm_fourcc.h>
20#include <drm/drm_gem_atomic_helper.h>
21#include <drm/drm_gem_framebuffer_helper.h>
22#include <drm/drm_gem_shmem_helper.h>
23#include <drm/drm_modeset_helper_vtables.h>
24#include <drm/drm_probe_helper.h>
25#include <drm/drm_vblank.h>
26
27#include "udl_drv.h"
28#include "udl_proto.h"
29
30/*
31 * All DisplayLink bulk operations start with 0xaf (UDL_MSG_BULK), followed by
32 * a specific command code. All operations are written to a command buffer, which
33 * the driver sends to the device.
34 */
35static char *udl_set_register(char *buf, u8 reg, u8 val)
36{
37	*buf++ = UDL_MSG_BULK;
38	*buf++ = UDL_CMD_WRITEREG;
39	*buf++ = reg;
40	*buf++ = val;
41
42	return buf;
43}
44
45static char *udl_vidreg_lock(char *buf)
46{
47	return udl_set_register(buf, UDL_REG_VIDREG, UDL_VIDREG_LOCK);
48}
49
50static char *udl_vidreg_unlock(char *buf)
51{
52	return udl_set_register(buf, UDL_REG_VIDREG, UDL_VIDREG_UNLOCK);
53}
54
55static char *udl_set_blank_mode(char *buf, u8 mode)
56{
57	return udl_set_register(buf, UDL_REG_BLANKMODE, mode);
58}
59
60static char *udl_set_color_depth(char *buf, u8 selection)
61{
62	return udl_set_register(buf, UDL_REG_COLORDEPTH, selection);
63}
64
65static char *udl_set_base16bpp(char *buf, u32 base)
66{
67	/* the base pointer is 24 bits wide, 0x20 is hi byte. */
68	u8 reg20 = FIELD_GET(UDL_BASE_ADDR2_MASK, base);
69	u8 reg21 = FIELD_GET(UDL_BASE_ADDR1_MASK, base);
70	u8 reg22 = FIELD_GET(UDL_BASE_ADDR0_MASK, base);
71
72	buf = udl_set_register(buf, UDL_REG_BASE16BPP_ADDR2, reg20);
73	buf = udl_set_register(buf, UDL_REG_BASE16BPP_ADDR1, reg21);
74	buf = udl_set_register(buf, UDL_REG_BASE16BPP_ADDR0, reg22);
75
76	return buf;
77}
78
79/*
80 * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
81 * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
82 */
83static char *udl_set_base8bpp(char *buf, u32 base)
84{
85	/* the base pointer is 24 bits wide, 0x26 is hi byte. */
86	u8 reg26 = FIELD_GET(UDL_BASE_ADDR2_MASK, base);
87	u8 reg27 = FIELD_GET(UDL_BASE_ADDR1_MASK, base);
88	u8 reg28 = FIELD_GET(UDL_BASE_ADDR0_MASK, base);
89
90	buf = udl_set_register(buf, UDL_REG_BASE8BPP_ADDR2, reg26);
91	buf = udl_set_register(buf, UDL_REG_BASE8BPP_ADDR1, reg27);
92	buf = udl_set_register(buf, UDL_REG_BASE8BPP_ADDR0, reg28);
93
94	return buf;
95}
96
97static char *udl_set_register_16(char *wrptr, u8 reg, u16 value)
98{
99	wrptr = udl_set_register(wrptr, reg, value >> 8);
100	return udl_set_register(wrptr, reg+1, value);
101}
102
103/*
104 * This is kind of weird because the controller takes some
105 * register values in a different byte order than other registers.
106 */
107static char *udl_set_register_16be(char *wrptr, u8 reg, u16 value)
108{
109	wrptr = udl_set_register(wrptr, reg, value);
110	return udl_set_register(wrptr, reg+1, value >> 8);
111}
112
113/*
114 * LFSR is linear feedback shift register. The reason we have this is
115 * because the display controller needs to minimize the clock depth of
116 * various counters used in the display path. So this code reverses the
117 * provided value into the lfsr16 value by counting backwards to get
118 * the value that needs to be set in the hardware comparator to get the
119 * same actual count. This makes sense once you read above a couple of
120 * times and think about it from a hardware perspective.
121 */
122static u16 udl_lfsr16(u16 actual_count)
123{
124	u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
125
126	while (actual_count--) {
127		lv =	 ((lv << 1) |
128			(((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
129			& 0xFFFF;
130	}
131
132	return (u16) lv;
133}
134
135/*
136 * This does LFSR conversion on the value that is to be written.
137 * See LFSR explanation above for more detail.
138 */
139static char *udl_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
140{
141	return udl_set_register_16(wrptr, reg, udl_lfsr16(value));
142}
143
144/*
145 * Takes a DRM display mode and converts it into the DisplayLink
146 * equivalent register commands.
147 */
148static char *udl_set_display_mode(char *buf, struct drm_display_mode *mode)
149{
150	u16 reg01 = mode->crtc_htotal - mode->crtc_hsync_start;
151	u16 reg03 = reg01 + mode->crtc_hdisplay;
152	u16 reg05 = mode->crtc_vtotal - mode->crtc_vsync_start;
153	u16 reg07 = reg05 + mode->crtc_vdisplay;
154	u16 reg09 = mode->crtc_htotal - 1;
155	u16 reg0b = 1; /* libdlo hardcodes hsync start to 1 */
156	u16 reg0d = mode->crtc_hsync_end - mode->crtc_hsync_start + 1;
157	u16 reg0f = mode->hdisplay;
158	u16 reg11 = mode->crtc_vtotal;
159	u16 reg13 = 0; /* libdlo hardcodes vsync start to 0 */
160	u16 reg15 = mode->crtc_vsync_end - mode->crtc_vsync_start;
161	u16 reg17 = mode->crtc_vdisplay;
162	u16 reg1b = mode->clock / 5;
163
164	buf = udl_set_register_lfsr16(buf, UDL_REG_XDISPLAYSTART, reg01);
165	buf = udl_set_register_lfsr16(buf, UDL_REG_XDISPLAYEND, reg03);
166	buf = udl_set_register_lfsr16(buf, UDL_REG_YDISPLAYSTART, reg05);
167	buf = udl_set_register_lfsr16(buf, UDL_REG_YDISPLAYEND, reg07);
168	buf = udl_set_register_lfsr16(buf, UDL_REG_XENDCOUNT, reg09);
169	buf = udl_set_register_lfsr16(buf, UDL_REG_HSYNCSTART, reg0b);
170	buf = udl_set_register_lfsr16(buf, UDL_REG_HSYNCEND, reg0d);
171	buf = udl_set_register_16(buf, UDL_REG_HPIXELS, reg0f);
172	buf = udl_set_register_lfsr16(buf, UDL_REG_YENDCOUNT, reg11);
173	buf = udl_set_register_lfsr16(buf, UDL_REG_VSYNCSTART, reg13);
174	buf = udl_set_register_lfsr16(buf, UDL_REG_VSYNCEND, reg15);
175	buf = udl_set_register_16(buf, UDL_REG_VPIXELS, reg17);
176	buf = udl_set_register_16be(buf, UDL_REG_PIXELCLOCK5KHZ, reg1b);
177
178	return buf;
179}
180
181static char *udl_dummy_render(char *wrptr)
182{
183	*wrptr++ = UDL_MSG_BULK;
184	*wrptr++ = UDL_CMD_WRITECOPY16;
185	*wrptr++ = 0x00; /* from addr */
186	*wrptr++ = 0x00;
187	*wrptr++ = 0x00;
188	*wrptr++ = 0x01; /* one pixel */
189	*wrptr++ = 0x00; /* to address */
190	*wrptr++ = 0x00;
191	*wrptr++ = 0x00;
192	return wrptr;
193}
194
195static long udl_log_cpp(unsigned int cpp)
196{
197	if (WARN_ON(!is_power_of_2(cpp)))
198		return -EINVAL;
199	return __ffs(cpp);
200}
201
202static int udl_handle_damage(struct drm_framebuffer *fb,
203			     const struct iosys_map *map,
204			     const struct drm_rect *clip)
205{
206	struct drm_device *dev = fb->dev;
207	void *vaddr = map->vaddr; /* TODO: Use mapping abstraction properly */
208	int i, ret;
209	char *cmd;
210	struct urb *urb;
211	int log_bpp;
212
213	ret = udl_log_cpp(fb->format->cpp[0]);
214	if (ret < 0)
215		return ret;
216	log_bpp = ret;
217
218	urb = udl_get_urb(dev);
219	if (!urb)
220		return -ENOMEM;
221	cmd = urb->transfer_buffer;
222
223	for (i = clip->y1; i < clip->y2; i++) {
224		const int line_offset = fb->pitches[0] * i;
225		const int byte_offset = line_offset + (clip->x1 << log_bpp);
226		const int dev_byte_offset = (fb->width * i + clip->x1) << log_bpp;
227		const int byte_width = drm_rect_width(clip) << log_bpp;
228		ret = udl_render_hline(dev, log_bpp, &urb, (char *)vaddr,
229				       &cmd, byte_offset, dev_byte_offset,
230				       byte_width);
231		if (ret)
232			return ret;
233	}
234
235	if (cmd > (char *)urb->transfer_buffer) {
236		/* Send partial buffer remaining before exiting */
237		int len;
238		if (cmd < (char *)urb->transfer_buffer + urb->transfer_buffer_length)
239			*cmd++ = UDL_MSG_BULK;
240		len = cmd - (char *)urb->transfer_buffer;
241		ret = udl_submit_urb(dev, urb, len);
242	} else {
243		udl_urb_completion(urb);
244	}
245
246	return 0;
247}
248
249/*
250 * Primary plane
251 */
252
253static const uint32_t udl_primary_plane_formats[] = {
254	DRM_FORMAT_RGB565,
255	DRM_FORMAT_XRGB8888,
256};
257
258static const uint64_t udl_primary_plane_fmtmods[] = {
259	DRM_FORMAT_MOD_LINEAR,
260	DRM_FORMAT_MOD_INVALID
261};
262
263static int udl_primary_plane_helper_atomic_check(struct drm_plane *plane,
264						 struct drm_atomic_state *state)
265{
266	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
267	struct drm_crtc *new_crtc = new_plane_state->crtc;
268	struct drm_crtc_state *new_crtc_state = NULL;
269
270	if (new_crtc)
271		new_crtc_state = drm_atomic_get_new_crtc_state(state, new_crtc);
272
273	return drm_atomic_helper_check_plane_state(new_plane_state, new_crtc_state,
274						   DRM_PLANE_NO_SCALING,
275						   DRM_PLANE_NO_SCALING,
276						   false, false);
277}
278
279static void udl_primary_plane_helper_atomic_update(struct drm_plane *plane,
280						   struct drm_atomic_state *state)
281{
282	struct drm_device *dev = plane->dev;
283	struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
284	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
285	struct drm_framebuffer *fb = plane_state->fb;
286	struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
287	struct drm_atomic_helper_damage_iter iter;
288	struct drm_rect damage;
289	int ret, idx;
290
291	if (!fb)
292		return; /* no framebuffer; plane is disabled */
293
294	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
295	if (ret)
296		return;
297
298	if (!drm_dev_enter(dev, &idx))
299		goto out_drm_gem_fb_end_cpu_access;
300
301	drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
302	drm_atomic_for_each_plane_damage(&iter, &damage) {
303		udl_handle_damage(fb, &shadow_plane_state->data[0], &damage);
304	}
305
306	drm_dev_exit(idx);
307
308out_drm_gem_fb_end_cpu_access:
309	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
310}
311
312static const struct drm_plane_helper_funcs udl_primary_plane_helper_funcs = {
313	DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
314	.atomic_check = udl_primary_plane_helper_atomic_check,
315	.atomic_update = udl_primary_plane_helper_atomic_update,
316};
317
318static const struct drm_plane_funcs udl_primary_plane_funcs = {
319	.update_plane = drm_atomic_helper_update_plane,
320	.disable_plane = drm_atomic_helper_disable_plane,
321	.destroy = drm_plane_cleanup,
322	DRM_GEM_SHADOW_PLANE_FUNCS,
323};
324
325/*
326 * CRTC
327 */
328
329static void udl_crtc_helper_atomic_enable(struct drm_crtc *crtc, struct drm_atomic_state *state)
330{
331	struct drm_device *dev = crtc->dev;
332	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
333	struct drm_display_mode *mode = &crtc_state->mode;
334	struct urb *urb;
335	char *buf;
336	int idx;
337
338	if (!drm_dev_enter(dev, &idx))
339		return;
340
341	urb = udl_get_urb(dev);
342	if (!urb)
343		goto out;
344
345	buf = (char *)urb->transfer_buffer;
346	buf = udl_vidreg_lock(buf);
347	buf = udl_set_color_depth(buf, UDL_COLORDEPTH_16BPP);
348	/* set base for 16bpp segment to 0 */
349	buf = udl_set_base16bpp(buf, 0);
350	/* set base for 8bpp segment to end of fb */
351	buf = udl_set_base8bpp(buf, 2 * mode->vdisplay * mode->hdisplay);
352	buf = udl_set_display_mode(buf, mode);
353	buf = udl_set_blank_mode(buf, UDL_BLANKMODE_ON);
354	buf = udl_vidreg_unlock(buf);
355	buf = udl_dummy_render(buf);
356
357	udl_submit_urb(dev, urb, buf - (char *)urb->transfer_buffer);
358
359out:
360	drm_dev_exit(idx);
361}
362
363static void udl_crtc_helper_atomic_disable(struct drm_crtc *crtc, struct drm_atomic_state *state)
364{
365	struct drm_device *dev = crtc->dev;
366	struct urb *urb;
367	char *buf;
368	int idx;
369
370	if (!drm_dev_enter(dev, &idx))
371		return;
372
373	urb = udl_get_urb(dev);
374	if (!urb)
375		goto out;
376
377	buf = (char *)urb->transfer_buffer;
378	buf = udl_vidreg_lock(buf);
379	buf = udl_set_blank_mode(buf, UDL_BLANKMODE_POWERDOWN);
380	buf = udl_vidreg_unlock(buf);
381	buf = udl_dummy_render(buf);
382
383	udl_submit_urb(dev, urb, buf - (char *)urb->transfer_buffer);
384
385out:
386	drm_dev_exit(idx);
387}
388
389static const struct drm_crtc_helper_funcs udl_crtc_helper_funcs = {
390	.atomic_check = drm_crtc_helper_atomic_check,
391	.atomic_enable = udl_crtc_helper_atomic_enable,
392	.atomic_disable = udl_crtc_helper_atomic_disable,
393};
394
395static const struct drm_crtc_funcs udl_crtc_funcs = {
396	.reset = drm_atomic_helper_crtc_reset,
397	.destroy = drm_crtc_cleanup,
398	.set_config = drm_atomic_helper_set_config,
399	.page_flip = drm_atomic_helper_page_flip,
400	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
401	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
402};
403
404/*
405 * Encoder
406 */
407
408static const struct drm_encoder_funcs udl_encoder_funcs = {
409	.destroy = drm_encoder_cleanup,
410};
411
412/*
413 * Connector
414 */
415
416static int udl_connector_helper_get_modes(struct drm_connector *connector)
417{
418	struct udl_connector *udl_connector = to_udl_connector(connector);
419
420	drm_connector_update_edid_property(connector, udl_connector->edid);
421	if (udl_connector->edid)
422		return drm_add_edid_modes(connector, udl_connector->edid);
423
424	return 0;
425}
426
427static const struct drm_connector_helper_funcs udl_connector_helper_funcs = {
428	.get_modes = udl_connector_helper_get_modes,
429};
430
431static int udl_get_edid_block(void *data, u8 *buf, unsigned int block, size_t len)
432{
433	struct udl_device *udl = data;
434	struct drm_device *dev = &udl->drm;
435	struct usb_device *udev = udl_to_usb_device(udl);
436	u8 *read_buff;
437	int ret;
438	size_t i;
439
440	read_buff = kmalloc(2, GFP_KERNEL);
441	if (!read_buff)
442		return -ENOMEM;
443
444	for (i = 0; i < len; i++) {
445		int bval = (i + block * EDID_LENGTH) << 8;
446
447		ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
448				      0x02, (0x80 | (0x02 << 5)), bval,
449				      0xA1, read_buff, 2, USB_CTRL_GET_TIMEOUT);
450		if (ret < 0) {
451			drm_err(dev, "Read EDID byte %zu failed err %x\n", i, ret);
452			goto err_kfree;
453		} else if (ret < 1) {
454			ret = -EIO;
455			drm_err(dev, "Read EDID byte %zu failed\n", i);
456			goto err_kfree;
457		}
458
459		buf[i] = read_buff[1];
460	}
461
462	kfree(read_buff);
463
464	return 0;
465
466err_kfree:
467	kfree(read_buff);
468	return ret;
469}
470
471static enum drm_connector_status udl_connector_detect(struct drm_connector *connector, bool force)
472{
473	struct drm_device *dev = connector->dev;
474	struct udl_device *udl = to_udl(dev);
475	struct udl_connector *udl_connector = to_udl_connector(connector);
476	enum drm_connector_status status = connector_status_disconnected;
477	int idx;
478
479	/* cleanup previous EDID */
480	kfree(udl_connector->edid);
481	udl_connector->edid = NULL;
482
483	if (!drm_dev_enter(dev, &idx))
484		return connector_status_disconnected;
485
486	udl_connector->edid = drm_do_get_edid(connector, udl_get_edid_block, udl);
487	if (udl_connector->edid)
488		status = connector_status_connected;
489
490	drm_dev_exit(idx);
491
492	return status;
493}
494
495static void udl_connector_destroy(struct drm_connector *connector)
496{
497	struct udl_connector *udl_connector = to_udl_connector(connector);
498
499	drm_connector_cleanup(connector);
500	kfree(udl_connector->edid);
501	kfree(udl_connector);
502}
503
504static const struct drm_connector_funcs udl_connector_funcs = {
505	.reset = drm_atomic_helper_connector_reset,
506	.detect = udl_connector_detect,
507	.fill_modes = drm_helper_probe_single_connector_modes,
508	.destroy = udl_connector_destroy,
509	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
510	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
511};
512
513struct drm_connector *udl_connector_init(struct drm_device *dev)
514{
515	struct udl_connector *udl_connector;
516	struct drm_connector *connector;
517	int ret;
518
519	udl_connector = kzalloc(sizeof(*udl_connector), GFP_KERNEL);
520	if (!udl_connector)
521		return ERR_PTR(-ENOMEM);
522
523	connector = &udl_connector->connector;
524	ret = drm_connector_init(dev, connector, &udl_connector_funcs, DRM_MODE_CONNECTOR_VGA);
525	if (ret)
526		goto err_kfree;
527
528	drm_connector_helper_add(connector, &udl_connector_helper_funcs);
529
530	connector->polled = DRM_CONNECTOR_POLL_HPD |
531			    DRM_CONNECTOR_POLL_CONNECT |
532			    DRM_CONNECTOR_POLL_DISCONNECT;
533
534	return connector;
535
536err_kfree:
537	kfree(udl_connector);
538	return ERR_PTR(ret);
539}
540
541/*
542 * Modesetting
543 */
544
545static enum drm_mode_status udl_mode_config_mode_valid(struct drm_device *dev,
546						       const struct drm_display_mode *mode)
547{
548	struct udl_device *udl = to_udl(dev);
549
550	if (udl->sku_pixel_limit) {
551		if (mode->vdisplay * mode->hdisplay > udl->sku_pixel_limit)
552			return MODE_MEM;
553	}
554
555	return MODE_OK;
556}
557
558static const struct drm_mode_config_funcs udl_mode_config_funcs = {
559	.fb_create = drm_gem_fb_create_with_dirty,
560	.mode_valid = udl_mode_config_mode_valid,
561	.atomic_check  = drm_atomic_helper_check,
562	.atomic_commit = drm_atomic_helper_commit,
563};
564
565int udl_modeset_init(struct drm_device *dev)
566{
567	struct udl_device *udl = to_udl(dev);
568	struct drm_plane *primary_plane;
569	struct drm_crtc *crtc;
570	struct drm_encoder *encoder;
571	struct drm_connector *connector;
572	int ret;
573
574	ret = drmm_mode_config_init(dev);
575	if (ret)
576		return ret;
577
578	dev->mode_config.min_width = 640;
579	dev->mode_config.min_height = 480;
580	dev->mode_config.max_width = 2048;
581	dev->mode_config.max_height = 2048;
582	dev->mode_config.preferred_depth = 16;
583	dev->mode_config.funcs = &udl_mode_config_funcs;
584
585	primary_plane = &udl->primary_plane;
586	ret = drm_universal_plane_init(dev, primary_plane, 0,
587				       &udl_primary_plane_funcs,
588				       udl_primary_plane_formats,
589				       ARRAY_SIZE(udl_primary_plane_formats),
590				       udl_primary_plane_fmtmods,
591				       DRM_PLANE_TYPE_PRIMARY, NULL);
592	if (ret)
593		return ret;
594	drm_plane_helper_add(primary_plane, &udl_primary_plane_helper_funcs);
595	drm_plane_enable_fb_damage_clips(primary_plane);
596
597	crtc = &udl->crtc;
598	ret = drm_crtc_init_with_planes(dev, crtc, primary_plane, NULL,
599					&udl_crtc_funcs, NULL);
600	if (ret)
601		return ret;
602	drm_crtc_helper_add(crtc, &udl_crtc_helper_funcs);
603
604	encoder = &udl->encoder;
605	ret = drm_encoder_init(dev, encoder, &udl_encoder_funcs, DRM_MODE_ENCODER_DAC, NULL);
606	if (ret)
607		return ret;
608	encoder->possible_crtcs = drm_crtc_mask(crtc);
609
610	connector = udl_connector_init(dev);
611	if (IS_ERR(connector))
612		return PTR_ERR(connector);
613	ret = drm_connector_attach_encoder(connector, encoder);
614	if (ret)
615		return ret;
616
617	drm_mode_config_reset(dev);
618
619	return 0;
620}
621