xref: /linux/drivers/gpu/drm/nouveau/dispnv04/dac.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 /*
2  * Copyright 2003 NVIDIA, Corporation
3  * Copyright 2006 Dave Airlie
4  * Copyright 2007 Maarten Maathuis
5  * Copyright 2007-2009 Stuart Bennett
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a
8  * copy of this software and associated documentation files (the "Software"),
9  * to deal in the Software without restriction, including without limitation
10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11  * and/or sell copies of the Software, and to permit persons to whom the
12  * Software is furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the next
15  * paragraph) shall be included in all copies or substantial portions of the
16  * Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
24  * DEALINGS IN THE SOFTWARE.
25  */
26 
27 #include <drm/drm_modeset_helper_vtables.h>
28 
29 #include "nouveau_drv.h"
30 #include "nouveau_encoder.h"
31 #include "nouveau_connector.h"
32 #include "nouveau_crtc.h"
33 #include "hw.h"
34 #include "nvreg.h"
35 
36 #include <subdev/bios/gpio.h>
37 #include <subdev/gpio.h>
38 
39 #include <nvif/timer.h>
40 
41 int nv04_dac_output_offset(struct drm_encoder *encoder)
42 {
43 	struct dcb_output *dcb = nouveau_encoder(encoder)->dcb;
44 	int offset = 0;
45 
46 	if (dcb->or & (8 | DCB_OUTPUT_C))
47 		offset += 0x68;
48 	if (dcb->or & (8 | DCB_OUTPUT_B))
49 		offset += 0x2000;
50 
51 	return offset;
52 }
53 
54 /*
55  * arbitrary limit to number of sense oscillations tolerated in one sample
56  * period (observed to be at least 13 in "nvidia")
57  */
58 #define MAX_HBLANK_OSC 20
59 
60 /*
61  * arbitrary limit to number of conflicting sample pairs to tolerate at a
62  * voltage step (observed to be at least 5 in "nvidia")
63  */
64 #define MAX_SAMPLE_PAIRS 10
65 
66 static int sample_load_twice(struct drm_device *dev, bool sense[2])
67 {
68 	struct nouveau_drm *drm = nouveau_drm(dev);
69 	struct nvif_object *device = &drm->client.device.object;
70 	int i;
71 
72 	for (i = 0; i < 2; i++) {
73 		bool sense_a, sense_b, sense_b_prime;
74 		int j = 0;
75 
76 		/*
77 		 * wait for bit 0 clear -- out of hblank -- (say reg value 0x4),
78 		 * then wait for transition 0x4->0x5->0x4: enter hblank, leave
79 		 * hblank again
80 		 * use a 10ms timeout (guards against crtc being inactive, in
81 		 * which case blank state would never change)
82 		 */
83 		if (nvif_msec(&drm->client.device, 10,
84 			if (!(nvif_rd32(device, NV_PRMCIO_INP0__COLOR) & 1))
85 				break;
86 		) < 0)
87 			return -EBUSY;
88 
89 		if (nvif_msec(&drm->client.device, 10,
90 			if ( (nvif_rd32(device, NV_PRMCIO_INP0__COLOR) & 1))
91 				break;
92 		) < 0)
93 			return -EBUSY;
94 
95 		if (nvif_msec(&drm->client.device, 10,
96 			if (!(nvif_rd32(device, NV_PRMCIO_INP0__COLOR) & 1))
97 				break;
98 		) < 0)
99 			return -EBUSY;
100 
101 		udelay(100);
102 		/* when level triggers, sense is _LO_ */
103 		sense_a = nvif_rd08(device, NV_PRMCIO_INP0) & 0x10;
104 
105 		/* take another reading until it agrees with sense_a... */
106 		do {
107 			udelay(100);
108 			sense_b = nvif_rd08(device, NV_PRMCIO_INP0) & 0x10;
109 			if (sense_a != sense_b) {
110 				sense_b_prime =
111 					nvif_rd08(device, NV_PRMCIO_INP0) & 0x10;
112 				if (sense_b == sense_b_prime) {
113 					/* ... unless two consecutive subsequent
114 					 * samples agree; sense_a is replaced */
115 					sense_a = sense_b;
116 					/* force mis-match so we loop */
117 					sense_b = !sense_a;
118 				}
119 			}
120 		} while ((sense_a != sense_b) && ++j < MAX_HBLANK_OSC);
121 
122 		if (j == MAX_HBLANK_OSC)
123 			/* with so much oscillation, default to sense:LO */
124 			sense[i] = false;
125 		else
126 			sense[i] = sense_a;
127 	}
128 
129 	return 0;
130 }
131 
132 static enum drm_connector_status nv04_dac_detect(struct drm_encoder *encoder,
133 						 struct drm_connector *connector)
134 {
135 	struct drm_device *dev = encoder->dev;
136 	struct nvif_object *device = &nouveau_drm(dev)->client.device.object;
137 	struct nouveau_drm *drm = nouveau_drm(dev);
138 	uint8_t saved_seq1, saved_pi, saved_rpc1, saved_cr_mode;
139 	uint8_t saved_palette0[3], saved_palette_mask;
140 	uint32_t saved_rtest_ctrl, saved_rgen_ctrl;
141 	int i;
142 	uint8_t blue;
143 	bool sense = true;
144 
145 	/*
146 	 * for this detection to work, there needs to be a mode set up on the
147 	 * CRTC.  this is presumed to be the case
148 	 */
149 
150 	if (nv_two_heads(dev))
151 		/* only implemented for head A for now */
152 		NVSetOwner(dev, 0);
153 
154 	saved_cr_mode = NVReadVgaCrtc(dev, 0, NV_CIO_CR_MODE_INDEX);
155 	NVWriteVgaCrtc(dev, 0, NV_CIO_CR_MODE_INDEX, saved_cr_mode | 0x80);
156 
157 	saved_seq1 = NVReadVgaSeq(dev, 0, NV_VIO_SR_CLOCK_INDEX);
158 	NVWriteVgaSeq(dev, 0, NV_VIO_SR_CLOCK_INDEX, saved_seq1 & ~0x20);
159 
160 	saved_rtest_ctrl = NVReadRAMDAC(dev, 0, NV_PRAMDAC_TEST_CONTROL);
161 	NVWriteRAMDAC(dev, 0, NV_PRAMDAC_TEST_CONTROL,
162 		      saved_rtest_ctrl & ~NV_PRAMDAC_TEST_CONTROL_PWRDWN_DAC_OFF);
163 
164 	msleep(10);
165 
166 	saved_pi = NVReadVgaCrtc(dev, 0, NV_CIO_CRE_PIXEL_INDEX);
167 	NVWriteVgaCrtc(dev, 0, NV_CIO_CRE_PIXEL_INDEX,
168 		       saved_pi & ~(0x80 | MASK(NV_CIO_CRE_PIXEL_FORMAT)));
169 	saved_rpc1 = NVReadVgaCrtc(dev, 0, NV_CIO_CRE_RPC1_INDEX);
170 	NVWriteVgaCrtc(dev, 0, NV_CIO_CRE_RPC1_INDEX, saved_rpc1 & ~0xc0);
171 
172 	nvif_wr08(device, NV_PRMDIO_READ_MODE_ADDRESS, 0x0);
173 	for (i = 0; i < 3; i++)
174 		saved_palette0[i] = nvif_rd08(device, NV_PRMDIO_PALETTE_DATA);
175 	saved_palette_mask = nvif_rd08(device, NV_PRMDIO_PIXEL_MASK);
176 	nvif_wr08(device, NV_PRMDIO_PIXEL_MASK, 0);
177 
178 	saved_rgen_ctrl = NVReadRAMDAC(dev, 0, NV_PRAMDAC_GENERAL_CONTROL);
179 	NVWriteRAMDAC(dev, 0, NV_PRAMDAC_GENERAL_CONTROL,
180 		      (saved_rgen_ctrl & ~(NV_PRAMDAC_GENERAL_CONTROL_BPC_8BITS |
181 					   NV_PRAMDAC_GENERAL_CONTROL_TERMINATION_75OHM)) |
182 		      NV_PRAMDAC_GENERAL_CONTROL_PIXMIX_ON);
183 
184 	blue = 8;	/* start of test range */
185 
186 	do {
187 		bool sense_pair[2];
188 
189 		nvif_wr08(device, NV_PRMDIO_WRITE_MODE_ADDRESS, 0);
190 		nvif_wr08(device, NV_PRMDIO_PALETTE_DATA, 0);
191 		nvif_wr08(device, NV_PRMDIO_PALETTE_DATA, 0);
192 		/* testing blue won't find monochrome monitors.  I don't care */
193 		nvif_wr08(device, NV_PRMDIO_PALETTE_DATA, blue);
194 
195 		i = 0;
196 		/* take sample pairs until both samples in the pair agree */
197 		do {
198 			if (sample_load_twice(dev, sense_pair))
199 				goto out;
200 		} while ((sense_pair[0] != sense_pair[1]) &&
201 							++i < MAX_SAMPLE_PAIRS);
202 
203 		if (i == MAX_SAMPLE_PAIRS)
204 			/* too much oscillation defaults to LO */
205 			sense = false;
206 		else
207 			sense = sense_pair[0];
208 
209 	/*
210 	 * if sense goes LO before blue ramps to 0x18, monitor is not connected.
211 	 * ergo, if blue gets to 0x18, monitor must be connected
212 	 */
213 	} while (++blue < 0x18 && sense);
214 
215 out:
216 	nvif_wr08(device, NV_PRMDIO_PIXEL_MASK, saved_palette_mask);
217 	NVWriteRAMDAC(dev, 0, NV_PRAMDAC_GENERAL_CONTROL, saved_rgen_ctrl);
218 	nvif_wr08(device, NV_PRMDIO_WRITE_MODE_ADDRESS, 0);
219 	for (i = 0; i < 3; i++)
220 		nvif_wr08(device, NV_PRMDIO_PALETTE_DATA, saved_palette0[i]);
221 	NVWriteRAMDAC(dev, 0, NV_PRAMDAC_TEST_CONTROL, saved_rtest_ctrl);
222 	NVWriteVgaCrtc(dev, 0, NV_CIO_CRE_PIXEL_INDEX, saved_pi);
223 	NVWriteVgaCrtc(dev, 0, NV_CIO_CRE_RPC1_INDEX, saved_rpc1);
224 	NVWriteVgaSeq(dev, 0, NV_VIO_SR_CLOCK_INDEX, saved_seq1);
225 	NVWriteVgaCrtc(dev, 0, NV_CIO_CR_MODE_INDEX, saved_cr_mode);
226 
227 	if (blue == 0x18) {
228 		NV_DEBUG(drm, "Load detected on head A\n");
229 		return connector_status_connected;
230 	}
231 
232 	return connector_status_disconnected;
233 }
234 
235 uint32_t nv17_dac_sample_load(struct drm_encoder *encoder)
236 {
237 	struct drm_device *dev = encoder->dev;
238 	struct nouveau_drm *drm = nouveau_drm(dev);
239 	struct nvif_object *device = &nouveau_drm(dev)->client.device.object;
240 	struct nvkm_gpio *gpio = nvxx_gpio(drm);
241 	struct dcb_output *dcb = nouveau_encoder(encoder)->dcb;
242 	uint32_t sample, testval, regoffset = nv04_dac_output_offset(encoder);
243 	uint32_t saved_powerctrl_2 = 0, saved_powerctrl_4 = 0, saved_routput,
244 		saved_rtest_ctrl, saved_gpio0 = 0, saved_gpio1 = 0, temp, routput;
245 	int head;
246 
247 #define RGB_TEST_DATA(r, g, b) (r << 0 | g << 10 | b << 20)
248 	if (dcb->type == DCB_OUTPUT_TV) {
249 		testval = RGB_TEST_DATA(0xa0, 0xa0, 0xa0);
250 
251 		if (drm->vbios.tvdactestval)
252 			testval = drm->vbios.tvdactestval;
253 	} else {
254 		testval = RGB_TEST_DATA(0x140, 0x140, 0x140); /* 0x94050140 */
255 
256 		if (drm->vbios.dactestval)
257 			testval = drm->vbios.dactestval;
258 	}
259 
260 	saved_rtest_ctrl = NVReadRAMDAC(dev, 0, NV_PRAMDAC_TEST_CONTROL + regoffset);
261 	NVWriteRAMDAC(dev, 0, NV_PRAMDAC_TEST_CONTROL + regoffset,
262 		      saved_rtest_ctrl & ~NV_PRAMDAC_TEST_CONTROL_PWRDWN_DAC_OFF);
263 
264 	saved_powerctrl_2 = nvif_rd32(device, NV_PBUS_POWERCTRL_2);
265 
266 	nvif_wr32(device, NV_PBUS_POWERCTRL_2, saved_powerctrl_2 & 0xd7ffffff);
267 	if (regoffset == 0x68) {
268 		saved_powerctrl_4 = nvif_rd32(device, NV_PBUS_POWERCTRL_4);
269 		nvif_wr32(device, NV_PBUS_POWERCTRL_4, saved_powerctrl_4 & 0xffffffcf);
270 	}
271 
272 	if (gpio) {
273 		saved_gpio1 = nvkm_gpio_get(gpio, 0, DCB_GPIO_TVDAC1, 0xff);
274 		saved_gpio0 = nvkm_gpio_get(gpio, 0, DCB_GPIO_TVDAC0, 0xff);
275 		nvkm_gpio_set(gpio, 0, DCB_GPIO_TVDAC1, 0xff, dcb->type == DCB_OUTPUT_TV);
276 		nvkm_gpio_set(gpio, 0, DCB_GPIO_TVDAC0, 0xff, dcb->type == DCB_OUTPUT_TV);
277 	}
278 
279 	msleep(4);
280 
281 	saved_routput = NVReadRAMDAC(dev, 0, NV_PRAMDAC_DACCLK + regoffset);
282 	head = (saved_routput & 0x100) >> 8;
283 
284 	/* if there's a spare crtc, using it will minimise flicker */
285 	if (!(NVReadVgaCrtc(dev, head, NV_CIO_CRE_RPC1_INDEX) & 0xC0))
286 		head ^= 1;
287 
288 	/* nv driver and nv31 use 0xfffffeee, nv34 and 6600 use 0xfffffece */
289 	routput = (saved_routput & 0xfffffece) | head << 8;
290 
291 	if (drm->client.device.info.family >= NV_DEVICE_INFO_V0_CURIE) {
292 		if (dcb->type == DCB_OUTPUT_TV)
293 			routput |= 0x1a << 16;
294 		else
295 			routput &= ~(0x1a << 16);
296 	}
297 
298 	NVWriteRAMDAC(dev, 0, NV_PRAMDAC_DACCLK + regoffset, routput);
299 	msleep(1);
300 
301 	temp = NVReadRAMDAC(dev, 0, NV_PRAMDAC_DACCLK + regoffset);
302 	NVWriteRAMDAC(dev, 0, NV_PRAMDAC_DACCLK + regoffset, temp | 1);
303 
304 	NVWriteRAMDAC(dev, head, NV_PRAMDAC_TESTPOINT_DATA,
305 		      NV_PRAMDAC_TESTPOINT_DATA_NOTBLANK | testval);
306 	temp = NVReadRAMDAC(dev, head, NV_PRAMDAC_TEST_CONTROL);
307 	NVWriteRAMDAC(dev, head, NV_PRAMDAC_TEST_CONTROL,
308 		      temp | NV_PRAMDAC_TEST_CONTROL_TP_INS_EN_ASSERTED);
309 	msleep(5);
310 
311 	sample = NVReadRAMDAC(dev, 0, NV_PRAMDAC_TEST_CONTROL + regoffset);
312 	/* do it again just in case it's a residual current */
313 	sample &= NVReadRAMDAC(dev, 0, NV_PRAMDAC_TEST_CONTROL + regoffset);
314 
315 	temp = NVReadRAMDAC(dev, head, NV_PRAMDAC_TEST_CONTROL);
316 	NVWriteRAMDAC(dev, head, NV_PRAMDAC_TEST_CONTROL,
317 		      temp & ~NV_PRAMDAC_TEST_CONTROL_TP_INS_EN_ASSERTED);
318 	NVWriteRAMDAC(dev, head, NV_PRAMDAC_TESTPOINT_DATA, 0);
319 
320 	/* bios does something more complex for restoring, but I think this is good enough */
321 	NVWriteRAMDAC(dev, 0, NV_PRAMDAC_DACCLK + regoffset, saved_routput);
322 	NVWriteRAMDAC(dev, 0, NV_PRAMDAC_TEST_CONTROL + regoffset, saved_rtest_ctrl);
323 	if (regoffset == 0x68)
324 		nvif_wr32(device, NV_PBUS_POWERCTRL_4, saved_powerctrl_4);
325 	nvif_wr32(device, NV_PBUS_POWERCTRL_2, saved_powerctrl_2);
326 
327 	if (gpio) {
328 		nvkm_gpio_set(gpio, 0, DCB_GPIO_TVDAC1, 0xff, saved_gpio1);
329 		nvkm_gpio_set(gpio, 0, DCB_GPIO_TVDAC0, 0xff, saved_gpio0);
330 	}
331 
332 	return sample;
333 }
334 
335 static enum drm_connector_status
336 nv17_dac_detect(struct drm_encoder *encoder, struct drm_connector *connector)
337 {
338 	struct nouveau_drm *drm = nouveau_drm(encoder->dev);
339 	struct dcb_output *dcb = nouveau_encoder(encoder)->dcb;
340 
341 	if (nv04_dac_in_use(encoder))
342 		return connector_status_disconnected;
343 
344 	if (nv17_dac_sample_load(encoder) &
345 	    NV_PRAMDAC_TEST_CONTROL_SENSEB_ALLHI) {
346 		NV_DEBUG(drm, "Load detected on output %c\n",
347 			 '@' + ffs(dcb->or));
348 		return connector_status_connected;
349 	} else {
350 		return connector_status_disconnected;
351 	}
352 }
353 
354 static bool nv04_dac_mode_fixup(struct drm_encoder *encoder,
355 				const struct drm_display_mode *mode,
356 				struct drm_display_mode *adjusted_mode)
357 {
358 	if (nv04_dac_in_use(encoder))
359 		return false;
360 
361 	return true;
362 }
363 
364 static void nv04_dac_prepare(struct drm_encoder *encoder)
365 {
366 	const struct drm_encoder_helper_funcs *helper = encoder->helper_private;
367 	struct drm_device *dev = encoder->dev;
368 	int head = nouveau_crtc(encoder->crtc)->index;
369 
370 	helper->dpms(encoder, DRM_MODE_DPMS_OFF);
371 
372 	nv04_dfp_disable(dev, head);
373 }
374 
375 static void nv04_dac_mode_set(struct drm_encoder *encoder,
376 			      struct drm_display_mode *mode,
377 			      struct drm_display_mode *adjusted_mode)
378 {
379 	struct drm_device *dev = encoder->dev;
380 	struct nouveau_drm *drm = nouveau_drm(dev);
381 	int head = nouveau_crtc(encoder->crtc)->index;
382 
383 	if (nv_gf4_disp_arch(dev)) {
384 		struct drm_encoder *rebind;
385 		uint32_t dac_offset = nv04_dac_output_offset(encoder);
386 		uint32_t otherdac;
387 
388 		/* bit 16-19 are bits that are set on some G70 cards,
389 		 * but don't seem to have much effect */
390 		NVWriteRAMDAC(dev, 0, NV_PRAMDAC_DACCLK + dac_offset,
391 			      head << 8 | NV_PRAMDAC_DACCLK_SEL_DACCLK);
392 		/* force any other vga encoders to bind to the other crtc */
393 		list_for_each_entry(rebind, &dev->mode_config.encoder_list, head) {
394 			if (rebind == encoder
395 			    || nouveau_encoder(rebind)->dcb->type != DCB_OUTPUT_ANALOG)
396 				continue;
397 
398 			dac_offset = nv04_dac_output_offset(rebind);
399 			otherdac = NVReadRAMDAC(dev, 0, NV_PRAMDAC_DACCLK + dac_offset);
400 			NVWriteRAMDAC(dev, 0, NV_PRAMDAC_DACCLK + dac_offset,
401 				      (otherdac & ~0x0100) | (head ^ 1) << 8);
402 		}
403 	}
404 
405 	/* This could use refinement for flatpanels, but it should work this way */
406 	if (drm->client.device.info.chipset < 0x44)
407 		NVWriteRAMDAC(dev, 0, NV_PRAMDAC_TEST_CONTROL + nv04_dac_output_offset(encoder), 0xf0000000);
408 	else
409 		NVWriteRAMDAC(dev, 0, NV_PRAMDAC_TEST_CONTROL + nv04_dac_output_offset(encoder), 0x00100000);
410 }
411 
412 static void nv04_dac_commit(struct drm_encoder *encoder)
413 {
414 	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
415 	struct nouveau_drm *drm = nouveau_drm(encoder->dev);
416 	struct nouveau_crtc *nv_crtc = nouveau_crtc(encoder->crtc);
417 	const struct drm_encoder_helper_funcs *helper = encoder->helper_private;
418 
419 	helper->dpms(encoder, DRM_MODE_DPMS_ON);
420 
421 	NV_DEBUG(drm, "Output %s is running on CRTC %d using output %c\n",
422 		 nv04_encoder_get_connector(nv_encoder)->base.name,
423 		 nv_crtc->index, '@' + ffs(nv_encoder->dcb->or));
424 }
425 
426 void nv04_dac_update_dacclk(struct drm_encoder *encoder, bool enable)
427 {
428 	struct drm_device *dev = encoder->dev;
429 	struct dcb_output *dcb = nouveau_encoder(encoder)->dcb;
430 
431 	if (nv_gf4_disp_arch(dev)) {
432 		uint32_t *dac_users = &nv04_display(dev)->dac_users[ffs(dcb->or) - 1];
433 		int dacclk_off = NV_PRAMDAC_DACCLK + nv04_dac_output_offset(encoder);
434 		uint32_t dacclk = NVReadRAMDAC(dev, 0, dacclk_off);
435 
436 		if (enable) {
437 			*dac_users |= 1 << dcb->index;
438 			NVWriteRAMDAC(dev, 0, dacclk_off, dacclk | NV_PRAMDAC_DACCLK_SEL_DACCLK);
439 
440 		} else {
441 			*dac_users &= ~(1 << dcb->index);
442 			if (!*dac_users)
443 				NVWriteRAMDAC(dev, 0, dacclk_off,
444 					dacclk & ~NV_PRAMDAC_DACCLK_SEL_DACCLK);
445 		}
446 	}
447 }
448 
449 /* Check if the DAC corresponding to 'encoder' is being used by
450  * someone else. */
451 bool nv04_dac_in_use(struct drm_encoder *encoder)
452 {
453 	struct drm_device *dev = encoder->dev;
454 	struct dcb_output *dcb = nouveau_encoder(encoder)->dcb;
455 
456 	return nv_gf4_disp_arch(encoder->dev) &&
457 		(nv04_display(dev)->dac_users[ffs(dcb->or) - 1] & ~(1 << dcb->index));
458 }
459 
460 static void nv04_dac_dpms(struct drm_encoder *encoder, int mode)
461 {
462 	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
463 	struct nouveau_drm *drm = nouveau_drm(encoder->dev);
464 
465 	if (nv_encoder->last_dpms == mode)
466 		return;
467 	nv_encoder->last_dpms = mode;
468 
469 	NV_DEBUG(drm, "Setting dpms mode %d on vga encoder (output %d)\n",
470 		 mode, nv_encoder->dcb->index);
471 
472 	nv04_dac_update_dacclk(encoder, mode == DRM_MODE_DPMS_ON);
473 }
474 
475 static void nv04_dac_save(struct drm_encoder *encoder)
476 {
477 	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
478 	struct drm_device *dev = encoder->dev;
479 
480 	if (nv_gf4_disp_arch(dev))
481 		nv_encoder->restore.output = NVReadRAMDAC(dev, 0, NV_PRAMDAC_DACCLK +
482 							  nv04_dac_output_offset(encoder));
483 }
484 
485 static void nv04_dac_restore(struct drm_encoder *encoder)
486 {
487 	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
488 	struct drm_device *dev = encoder->dev;
489 
490 	if (nv_gf4_disp_arch(dev))
491 		NVWriteRAMDAC(dev, 0, NV_PRAMDAC_DACCLK + nv04_dac_output_offset(encoder),
492 			      nv_encoder->restore.output);
493 
494 	nv_encoder->last_dpms = NV_DPMS_CLEARED;
495 }
496 
497 static void nv04_dac_destroy(struct drm_encoder *encoder)
498 {
499 	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
500 
501 	drm_encoder_cleanup(encoder);
502 	kfree(nv_encoder);
503 }
504 
505 static const struct drm_encoder_helper_funcs nv04_dac_helper_funcs = {
506 	.dpms = nv04_dac_dpms,
507 	.mode_fixup = nv04_dac_mode_fixup,
508 	.prepare = nv04_dac_prepare,
509 	.commit = nv04_dac_commit,
510 	.mode_set = nv04_dac_mode_set,
511 	.detect = nv04_dac_detect
512 };
513 
514 static const struct drm_encoder_helper_funcs nv17_dac_helper_funcs = {
515 	.dpms = nv04_dac_dpms,
516 	.mode_fixup = nv04_dac_mode_fixup,
517 	.prepare = nv04_dac_prepare,
518 	.commit = nv04_dac_commit,
519 	.mode_set = nv04_dac_mode_set,
520 	.detect = nv17_dac_detect
521 };
522 
523 static const struct drm_encoder_funcs nv04_dac_funcs = {
524 	.destroy = nv04_dac_destroy,
525 };
526 
527 int
528 nv04_dac_create(struct drm_connector *connector, struct dcb_output *entry)
529 {
530 	const struct drm_encoder_helper_funcs *helper;
531 	struct nouveau_encoder *nv_encoder = NULL;
532 	struct drm_device *dev = connector->dev;
533 	struct drm_encoder *encoder;
534 
535 	nv_encoder = kzalloc(sizeof(*nv_encoder), GFP_KERNEL);
536 	if (!nv_encoder)
537 		return -ENOMEM;
538 
539 	encoder = to_drm_encoder(nv_encoder);
540 
541 	nv_encoder->dcb = entry;
542 	nv_encoder->or = ffs(entry->or) - 1;
543 
544 	nv_encoder->enc_save = nv04_dac_save;
545 	nv_encoder->enc_restore = nv04_dac_restore;
546 
547 	if (nv_gf4_disp_arch(dev))
548 		helper = &nv17_dac_helper_funcs;
549 	else
550 		helper = &nv04_dac_helper_funcs;
551 
552 	drm_encoder_init(dev, encoder, &nv04_dac_funcs, DRM_MODE_ENCODER_DAC,
553 			 NULL);
554 	drm_encoder_helper_add(encoder, helper);
555 
556 	encoder->possible_crtcs = entry->heads;
557 	encoder->possible_clones = 0;
558 
559 	drm_connector_attach_encoder(connector, encoder);
560 	return 0;
561 }
562