xref: /openbmc/linux/drivers/gpu/drm/udl/udl_modeset.c (revision 9cfc5c90)
1 /*
2  * Copyright (C) 2012 Red Hat
3  *
4  * based in parts on udlfb.c:
5  * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
6  * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
7  * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
8 
9  * This file is subject to the terms and conditions of the GNU General Public
10  * License v2. See the file COPYING in the main directory of this archive for
11  * more details.
12  */
13 
14 #include <drm/drmP.h>
15 #include <drm/drm_crtc.h>
16 #include <drm/drm_crtc_helper.h>
17 #include <drm/drm_plane_helper.h>
18 #include "udl_drv.h"
19 
20 /*
21  * All DisplayLink bulk operations start with 0xAF, followed by specific code
22  * All operations are written to buffers which then later get sent to device
23  */
24 static char *udl_set_register(char *buf, u8 reg, u8 val)
25 {
26 	*buf++ = 0xAF;
27 	*buf++ = 0x20;
28 	*buf++ = reg;
29 	*buf++ = val;
30 	return buf;
31 }
32 
33 static char *udl_vidreg_lock(char *buf)
34 {
35 	return udl_set_register(buf, 0xFF, 0x00);
36 }
37 
38 static char *udl_vidreg_unlock(char *buf)
39 {
40 	return udl_set_register(buf, 0xFF, 0xFF);
41 }
42 
43 /*
44  * On/Off for driving the DisplayLink framebuffer to the display
45  *  0x00 H and V sync on
46  *  0x01 H and V sync off (screen blank but powered)
47  *  0x07 DPMS powerdown (requires modeset to come back)
48  */
49 static char *udl_set_blank(char *buf, int dpms_mode)
50 {
51 	u8 reg;
52 	switch (dpms_mode) {
53 	case DRM_MODE_DPMS_OFF:
54 		reg = 0x07;
55 		break;
56 	case DRM_MODE_DPMS_STANDBY:
57 		reg = 0x05;
58 		break;
59 	case DRM_MODE_DPMS_SUSPEND:
60 		reg = 0x01;
61 		break;
62 	case DRM_MODE_DPMS_ON:
63 		reg = 0x00;
64 		break;
65 	}
66 
67 	return udl_set_register(buf, 0x1f, reg);
68 }
69 
70 static char *udl_set_color_depth(char *buf, u8 selection)
71 {
72 	return udl_set_register(buf, 0x00, selection);
73 }
74 
75 static char *udl_set_base16bpp(char *wrptr, u32 base)
76 {
77 	/* the base pointer is 16 bits wide, 0x20 is hi byte. */
78 	wrptr = udl_set_register(wrptr, 0x20, base >> 16);
79 	wrptr = udl_set_register(wrptr, 0x21, base >> 8);
80 	return udl_set_register(wrptr, 0x22, base);
81 }
82 
83 /*
84  * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
85  * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
86  */
87 static char *udl_set_base8bpp(char *wrptr, u32 base)
88 {
89 	wrptr = udl_set_register(wrptr, 0x26, base >> 16);
90 	wrptr = udl_set_register(wrptr, 0x27, base >> 8);
91 	return udl_set_register(wrptr, 0x28, base);
92 }
93 
94 static char *udl_set_register_16(char *wrptr, u8 reg, u16 value)
95 {
96 	wrptr = udl_set_register(wrptr, reg, value >> 8);
97 	return udl_set_register(wrptr, reg+1, value);
98 }
99 
100 /*
101  * This is kind of weird because the controller takes some
102  * register values in a different byte order than other registers.
103  */
104 static char *udl_set_register_16be(char *wrptr, u8 reg, u16 value)
105 {
106 	wrptr = udl_set_register(wrptr, reg, value);
107 	return udl_set_register(wrptr, reg+1, value >> 8);
108 }
109 
110 /*
111  * LFSR is linear feedback shift register. The reason we have this is
112  * because the display controller needs to minimize the clock depth of
113  * various counters used in the display path. So this code reverses the
114  * provided value into the lfsr16 value by counting backwards to get
115  * the value that needs to be set in the hardware comparator to get the
116  * same actual count. This makes sense once you read above a couple of
117  * times and think about it from a hardware perspective.
118  */
119 static u16 udl_lfsr16(u16 actual_count)
120 {
121 	u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
122 
123 	while (actual_count--) {
124 		lv =	 ((lv << 1) |
125 			(((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
126 			& 0xFFFF;
127 	}
128 
129 	return (u16) lv;
130 }
131 
132 /*
133  * This does LFSR conversion on the value that is to be written.
134  * See LFSR explanation above for more detail.
135  */
136 static char *udl_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
137 {
138 	return udl_set_register_16(wrptr, reg, udl_lfsr16(value));
139 }
140 
141 /*
142  * This takes a standard fbdev screeninfo struct and all of its monitor mode
143  * details and converts them into the DisplayLink equivalent register commands.
144   ERR(vreg(dev,               0x00, (color_depth == 16) ? 0 : 1));
145   ERR(vreg_lfsr16(dev,        0x01, xDisplayStart));
146   ERR(vreg_lfsr16(dev,        0x03, xDisplayEnd));
147   ERR(vreg_lfsr16(dev,        0x05, yDisplayStart));
148   ERR(vreg_lfsr16(dev,        0x07, yDisplayEnd));
149   ERR(vreg_lfsr16(dev,        0x09, xEndCount));
150   ERR(vreg_lfsr16(dev,        0x0B, hSyncStart));
151   ERR(vreg_lfsr16(dev,        0x0D, hSyncEnd));
152   ERR(vreg_big_endian(dev,    0x0F, hPixels));
153   ERR(vreg_lfsr16(dev,        0x11, yEndCount));
154   ERR(vreg_lfsr16(dev,        0x13, vSyncStart));
155   ERR(vreg_lfsr16(dev,        0x15, vSyncEnd));
156   ERR(vreg_big_endian(dev,    0x17, vPixels));
157   ERR(vreg_little_endian(dev, 0x1B, pixelClock5KHz));
158 
159   ERR(vreg(dev,               0x1F, 0));
160 
161   ERR(vbuf(dev, WRITE_VIDREG_UNLOCK, DSIZEOF(WRITE_VIDREG_UNLOCK)));
162  */
163 static char *udl_set_vid_cmds(char *wrptr, struct drm_display_mode *mode)
164 {
165 	u16 xds, yds;
166 	u16 xde, yde;
167 	u16 yec;
168 
169 	/* x display start */
170 	xds = mode->crtc_htotal - mode->crtc_hsync_start;
171 	wrptr = udl_set_register_lfsr16(wrptr, 0x01, xds);
172 	/* x display end */
173 	xde = xds + mode->crtc_hdisplay;
174 	wrptr = udl_set_register_lfsr16(wrptr, 0x03, xde);
175 
176 	/* y display start */
177 	yds = mode->crtc_vtotal - mode->crtc_vsync_start;
178 	wrptr = udl_set_register_lfsr16(wrptr, 0x05, yds);
179 	/* y display end */
180 	yde = yds + mode->crtc_vdisplay;
181 	wrptr = udl_set_register_lfsr16(wrptr, 0x07, yde);
182 
183 	/* x end count is active + blanking - 1 */
184 	wrptr = udl_set_register_lfsr16(wrptr, 0x09,
185 					mode->crtc_htotal - 1);
186 
187 	/* libdlo hardcodes hsync start to 1 */
188 	wrptr = udl_set_register_lfsr16(wrptr, 0x0B, 1);
189 
190 	/* hsync end is width of sync pulse + 1 */
191 	wrptr = udl_set_register_lfsr16(wrptr, 0x0D,
192 					mode->crtc_hsync_end - mode->crtc_hsync_start + 1);
193 
194 	/* hpixels is active pixels */
195 	wrptr = udl_set_register_16(wrptr, 0x0F, mode->hdisplay);
196 
197 	/* yendcount is vertical active + vertical blanking */
198 	yec = mode->crtc_vtotal;
199 	wrptr = udl_set_register_lfsr16(wrptr, 0x11, yec);
200 
201 	/* libdlo hardcodes vsync start to 0 */
202 	wrptr = udl_set_register_lfsr16(wrptr, 0x13, 0);
203 
204 	/* vsync end is width of vsync pulse */
205 	wrptr = udl_set_register_lfsr16(wrptr, 0x15, mode->crtc_vsync_end - mode->crtc_vsync_start);
206 
207 	/* vpixels is active pixels */
208 	wrptr = udl_set_register_16(wrptr, 0x17, mode->crtc_vdisplay);
209 
210 	wrptr = udl_set_register_16be(wrptr, 0x1B,
211 				      mode->clock / 5);
212 
213 	return wrptr;
214 }
215 
216 static char *udl_dummy_render(char *wrptr)
217 {
218 	*wrptr++ = 0xAF;
219 	*wrptr++ = 0x6A; /* copy */
220 	*wrptr++ = 0x00; /* from addr */
221 	*wrptr++ = 0x00;
222 	*wrptr++ = 0x00;
223 	*wrptr++ = 0x01; /* one pixel */
224 	*wrptr++ = 0x00; /* to address */
225 	*wrptr++ = 0x00;
226 	*wrptr++ = 0x00;
227 	return wrptr;
228 }
229 
230 static int udl_crtc_write_mode_to_hw(struct drm_crtc *crtc)
231 {
232 	struct drm_device *dev = crtc->dev;
233 	struct udl_device *udl = dev->dev_private;
234 	struct urb *urb;
235 	char *buf;
236 	int retval;
237 
238 	urb = udl_get_urb(dev);
239 	if (!urb)
240 		return -ENOMEM;
241 
242 	buf = (char *)urb->transfer_buffer;
243 
244 	memcpy(buf, udl->mode_buf, udl->mode_buf_len);
245 	retval = udl_submit_urb(dev, urb, udl->mode_buf_len);
246 	DRM_INFO("write mode info %d\n", udl->mode_buf_len);
247 	return retval;
248 }
249 
250 
251 static void udl_crtc_dpms(struct drm_crtc *crtc, int mode)
252 {
253 	struct drm_device *dev = crtc->dev;
254 	struct udl_device *udl = dev->dev_private;
255 	int retval;
256 
257 	if (mode == DRM_MODE_DPMS_OFF) {
258 		char *buf;
259 		struct urb *urb;
260 		urb = udl_get_urb(dev);
261 		if (!urb)
262 			return;
263 
264 		buf = (char *)urb->transfer_buffer;
265 		buf = udl_vidreg_lock(buf);
266 		buf = udl_set_blank(buf, mode);
267 		buf = udl_vidreg_unlock(buf);
268 
269 		buf = udl_dummy_render(buf);
270 		retval = udl_submit_urb(dev, urb, buf - (char *)
271 					urb->transfer_buffer);
272 	} else {
273 		if (udl->mode_buf_len == 0) {
274 			DRM_ERROR("Trying to enable DPMS with no mode\n");
275 			return;
276 		}
277 		udl_crtc_write_mode_to_hw(crtc);
278 	}
279 
280 }
281 
282 static bool udl_crtc_mode_fixup(struct drm_crtc *crtc,
283 				  const struct drm_display_mode *mode,
284 				  struct drm_display_mode *adjusted_mode)
285 
286 {
287 	return true;
288 }
289 
290 #if 0
291 static int
292 udl_pipe_set_base_atomic(struct drm_crtc *crtc, struct drm_framebuffer *fb,
293 			   int x, int y, enum mode_set_atomic state)
294 {
295 	return 0;
296 }
297 
298 static int
299 udl_pipe_set_base(struct drm_crtc *crtc, int x, int y,
300 		    struct drm_framebuffer *old_fb)
301 {
302 	return 0;
303 }
304 #endif
305 
306 static int udl_crtc_mode_set(struct drm_crtc *crtc,
307 			       struct drm_display_mode *mode,
308 			       struct drm_display_mode *adjusted_mode,
309 			       int x, int y,
310 			       struct drm_framebuffer *old_fb)
311 
312 {
313 	struct drm_device *dev = crtc->dev;
314 	struct udl_framebuffer *ufb = to_udl_fb(crtc->primary->fb);
315 	struct udl_device *udl = dev->dev_private;
316 	char *buf;
317 	char *wrptr;
318 	int color_depth = 0;
319 
320 	buf = (char *)udl->mode_buf;
321 
322 	/* for now we just clip 24 -> 16 - if we fix that fix this */
323 	/*if  (crtc->fb->bits_per_pixel != 16)
324 	  color_depth = 1; */
325 
326 	/* This first section has to do with setting the base address on the
327 	* controller * associated with the display. There are 2 base
328 	* pointers, currently, we only * use the 16 bpp segment.
329 	*/
330 	wrptr = udl_vidreg_lock(buf);
331 	wrptr = udl_set_color_depth(wrptr, color_depth);
332 	/* set base for 16bpp segment to 0 */
333 	wrptr = udl_set_base16bpp(wrptr, 0);
334 	/* set base for 8bpp segment to end of fb */
335 	wrptr = udl_set_base8bpp(wrptr, 2 * mode->vdisplay * mode->hdisplay);
336 
337 	wrptr = udl_set_vid_cmds(wrptr, adjusted_mode);
338 	wrptr = udl_set_blank(wrptr, DRM_MODE_DPMS_ON);
339 	wrptr = udl_vidreg_unlock(wrptr);
340 
341 	wrptr = udl_dummy_render(wrptr);
342 
343 	if (old_fb) {
344 		struct udl_framebuffer *uold_fb = to_udl_fb(old_fb);
345 		uold_fb->active_16 = false;
346 	}
347 	ufb->active_16 = true;
348 	udl->mode_buf_len = wrptr - buf;
349 
350 	/* damage all of it */
351 	udl_handle_damage(ufb, 0, 0, ufb->base.width, ufb->base.height);
352 	return 0;
353 }
354 
355 
356 static void udl_crtc_disable(struct drm_crtc *crtc)
357 {
358 	udl_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
359 }
360 
361 static void udl_crtc_destroy(struct drm_crtc *crtc)
362 {
363 	drm_crtc_cleanup(crtc);
364 	kfree(crtc);
365 }
366 
367 static int udl_crtc_page_flip(struct drm_crtc *crtc,
368 			      struct drm_framebuffer *fb,
369 			      struct drm_pending_vblank_event *event,
370 			      uint32_t page_flip_flags)
371 {
372 	struct udl_framebuffer *ufb = to_udl_fb(fb);
373 	struct drm_device *dev = crtc->dev;
374 	unsigned long flags;
375 
376 	struct drm_framebuffer *old_fb = crtc->primary->fb;
377 	if (old_fb) {
378 		struct udl_framebuffer *uold_fb = to_udl_fb(old_fb);
379 		uold_fb->active_16 = false;
380 	}
381 	ufb->active_16 = true;
382 
383 	udl_handle_damage(ufb, 0, 0, fb->width, fb->height);
384 
385 	spin_lock_irqsave(&dev->event_lock, flags);
386 	if (event)
387 		drm_send_vblank_event(dev, 0, event);
388 	spin_unlock_irqrestore(&dev->event_lock, flags);
389 	crtc->primary->fb = fb;
390 
391 	return 0;
392 }
393 
394 static void udl_crtc_prepare(struct drm_crtc *crtc)
395 {
396 }
397 
398 static void udl_crtc_commit(struct drm_crtc *crtc)
399 {
400 	udl_crtc_dpms(crtc, DRM_MODE_DPMS_ON);
401 }
402 
403 static struct drm_crtc_helper_funcs udl_helper_funcs = {
404 	.dpms = udl_crtc_dpms,
405 	.mode_fixup = udl_crtc_mode_fixup,
406 	.mode_set = udl_crtc_mode_set,
407 	.prepare = udl_crtc_prepare,
408 	.commit = udl_crtc_commit,
409 	.disable = udl_crtc_disable,
410 };
411 
412 static const struct drm_crtc_funcs udl_crtc_funcs = {
413 	.set_config = drm_crtc_helper_set_config,
414 	.destroy = udl_crtc_destroy,
415 	.page_flip = udl_crtc_page_flip,
416 };
417 
418 static int udl_crtc_init(struct drm_device *dev)
419 {
420 	struct drm_crtc *crtc;
421 
422 	crtc = kzalloc(sizeof(struct drm_crtc) + sizeof(struct drm_connector *), GFP_KERNEL);
423 	if (crtc == NULL)
424 		return -ENOMEM;
425 
426 	drm_crtc_init(dev, crtc, &udl_crtc_funcs);
427 	drm_crtc_helper_add(crtc, &udl_helper_funcs);
428 
429 	return 0;
430 }
431 
432 static const struct drm_mode_config_funcs udl_mode_funcs = {
433 	.fb_create = udl_fb_user_fb_create,
434 	.output_poll_changed = NULL,
435 };
436 
437 int udl_modeset_init(struct drm_device *dev)
438 {
439 	struct drm_encoder *encoder;
440 	drm_mode_config_init(dev);
441 
442 	dev->mode_config.min_width = 640;
443 	dev->mode_config.min_height = 480;
444 
445 	dev->mode_config.max_width = 2048;
446 	dev->mode_config.max_height = 2048;
447 
448 	dev->mode_config.prefer_shadow = 0;
449 	dev->mode_config.preferred_depth = 24;
450 
451 	dev->mode_config.funcs = &udl_mode_funcs;
452 
453 	drm_mode_create_dirty_info_property(dev);
454 
455 	udl_crtc_init(dev);
456 
457 	encoder = udl_encoder_init(dev);
458 
459 	udl_connector_init(dev, encoder);
460 
461 	return 0;
462 }
463 
464 void udl_modeset_cleanup(struct drm_device *dev)
465 {
466 	drm_mode_config_cleanup(dev);
467 }
468