xref: /linux/drivers/gpu/drm/i915/display/intel_fdi.c (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2020 Intel Corporation
4  */
5 
6 #include <linux/string_helpers.h>
7 
8 #include "i915_reg.h"
9 #include "intel_atomic.h"
10 #include "intel_crtc.h"
11 #include "intel_ddi.h"
12 #include "intel_de.h"
13 #include "intel_display_types.h"
14 #include "intel_fdi.h"
15 #include "intel_fdi_regs.h"
16 #include "intel_link_bw.h"
17 
18 struct intel_fdi_funcs {
19 	void (*fdi_link_train)(struct intel_crtc *crtc,
20 			       const struct intel_crtc_state *crtc_state);
21 };
22 
23 static void assert_fdi_tx(struct drm_i915_private *dev_priv,
24 			  enum pipe pipe, bool state)
25 {
26 	bool cur_state;
27 
28 	if (HAS_DDI(dev_priv)) {
29 		/*
30 		 * DDI does not have a specific FDI_TX register.
31 		 *
32 		 * FDI is never fed from EDP transcoder
33 		 * so pipe->transcoder cast is fine here.
34 		 */
35 		enum transcoder cpu_transcoder = (enum transcoder)pipe;
36 		cur_state = intel_de_read(dev_priv, TRANS_DDI_FUNC_CTL(cpu_transcoder)) & TRANS_DDI_FUNC_ENABLE;
37 	} else {
38 		cur_state = intel_de_read(dev_priv, FDI_TX_CTL(pipe)) & FDI_TX_ENABLE;
39 	}
40 	I915_STATE_WARN(dev_priv, cur_state != state,
41 			"FDI TX state assertion failure (expected %s, current %s)\n",
42 			str_on_off(state), str_on_off(cur_state));
43 }
44 
45 void assert_fdi_tx_enabled(struct drm_i915_private *i915, enum pipe pipe)
46 {
47 	assert_fdi_tx(i915, pipe, true);
48 }
49 
50 void assert_fdi_tx_disabled(struct drm_i915_private *i915, enum pipe pipe)
51 {
52 	assert_fdi_tx(i915, pipe, false);
53 }
54 
55 static void assert_fdi_rx(struct drm_i915_private *dev_priv,
56 			  enum pipe pipe, bool state)
57 {
58 	bool cur_state;
59 
60 	cur_state = intel_de_read(dev_priv, FDI_RX_CTL(pipe)) & FDI_RX_ENABLE;
61 	I915_STATE_WARN(dev_priv, cur_state != state,
62 			"FDI RX state assertion failure (expected %s, current %s)\n",
63 			str_on_off(state), str_on_off(cur_state));
64 }
65 
66 void assert_fdi_rx_enabled(struct drm_i915_private *i915, enum pipe pipe)
67 {
68 	assert_fdi_rx(i915, pipe, true);
69 }
70 
71 void assert_fdi_rx_disabled(struct drm_i915_private *i915, enum pipe pipe)
72 {
73 	assert_fdi_rx(i915, pipe, false);
74 }
75 
76 void assert_fdi_tx_pll_enabled(struct drm_i915_private *i915,
77 			       enum pipe pipe)
78 {
79 	bool cur_state;
80 
81 	/* ILK FDI PLL is always enabled */
82 	if (IS_IRONLAKE(i915))
83 		return;
84 
85 	/* On Haswell, DDI ports are responsible for the FDI PLL setup */
86 	if (HAS_DDI(i915))
87 		return;
88 
89 	cur_state = intel_de_read(i915, FDI_TX_CTL(pipe)) & FDI_TX_PLL_ENABLE;
90 	I915_STATE_WARN(i915, !cur_state,
91 			"FDI TX PLL assertion failure, should be active but is disabled\n");
92 }
93 
94 static void assert_fdi_rx_pll(struct drm_i915_private *i915,
95 			      enum pipe pipe, bool state)
96 {
97 	bool cur_state;
98 
99 	cur_state = intel_de_read(i915, FDI_RX_CTL(pipe)) & FDI_RX_PLL_ENABLE;
100 	I915_STATE_WARN(i915, cur_state != state,
101 			"FDI RX PLL assertion failure (expected %s, current %s)\n",
102 			str_on_off(state), str_on_off(cur_state));
103 }
104 
105 void assert_fdi_rx_pll_enabled(struct drm_i915_private *i915, enum pipe pipe)
106 {
107 	assert_fdi_rx_pll(i915, pipe, true);
108 }
109 
110 void assert_fdi_rx_pll_disabled(struct drm_i915_private *i915, enum pipe pipe)
111 {
112 	assert_fdi_rx_pll(i915, pipe, false);
113 }
114 
115 void intel_fdi_link_train(struct intel_crtc *crtc,
116 			  const struct intel_crtc_state *crtc_state)
117 {
118 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
119 
120 	dev_priv->display.funcs.fdi->fdi_link_train(crtc, crtc_state);
121 }
122 
123 /**
124  * intel_fdi_add_affected_crtcs - add CRTCs on FDI affected by other modeset CRTCs
125  * @state: intel atomic state
126  *
127  * Add a CRTC using FDI to @state if changing another CRTC's FDI BW usage is
128  * known to affect the available FDI BW for the former CRTC. In practice this
129  * means adding CRTC B on IVYBRIDGE if its use of FDI lanes is limited (by
130  * CRTC C) and CRTC C is getting disabled.
131  *
132  * Returns 0 in case of success, or a negative error code otherwise.
133  */
134 int intel_fdi_add_affected_crtcs(struct intel_atomic_state *state)
135 {
136 	struct drm_i915_private *i915 = to_i915(state->base.dev);
137 	const struct intel_crtc_state *old_crtc_state;
138 	const struct intel_crtc_state *new_crtc_state;
139 	struct intel_crtc *crtc;
140 
141 	if (!IS_IVYBRIDGE(i915) || INTEL_NUM_PIPES(i915) != 3)
142 		return 0;
143 
144 	crtc = intel_crtc_for_pipe(i915, PIPE_C);
145 	new_crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
146 	if (!new_crtc_state)
147 		return 0;
148 
149 	if (!intel_crtc_needs_modeset(new_crtc_state))
150 		return 0;
151 
152 	old_crtc_state = intel_atomic_get_old_crtc_state(state, crtc);
153 	if (!old_crtc_state->fdi_lanes)
154 		return 0;
155 
156 	crtc = intel_crtc_for_pipe(i915, PIPE_B);
157 	new_crtc_state = intel_atomic_get_crtc_state(&state->base, crtc);
158 	if (IS_ERR(new_crtc_state))
159 		return PTR_ERR(new_crtc_state);
160 
161 	old_crtc_state = intel_atomic_get_old_crtc_state(state, crtc);
162 	if (!old_crtc_state->fdi_lanes)
163 		return 0;
164 
165 	return intel_modeset_pipes_in_mask_early(state,
166 						 "FDI link BW decrease on pipe C",
167 						 BIT(PIPE_B));
168 }
169 
170 /* units of 100MHz */
171 static int pipe_required_fdi_lanes(struct intel_crtc_state *crtc_state)
172 {
173 	if (crtc_state->hw.enable && crtc_state->has_pch_encoder)
174 		return crtc_state->fdi_lanes;
175 
176 	return 0;
177 }
178 
179 static int ilk_check_fdi_lanes(struct drm_device *dev, enum pipe pipe,
180 			       struct intel_crtc_state *pipe_config,
181 			       enum pipe *pipe_to_reduce)
182 {
183 	struct drm_i915_private *dev_priv = to_i915(dev);
184 	struct drm_atomic_state *state = pipe_config->uapi.state;
185 	struct intel_crtc *other_crtc;
186 	struct intel_crtc_state *other_crtc_state;
187 
188 	*pipe_to_reduce = pipe;
189 
190 	drm_dbg_kms(&dev_priv->drm,
191 		    "checking fdi config on pipe %c, lanes %i\n",
192 		    pipe_name(pipe), pipe_config->fdi_lanes);
193 	if (pipe_config->fdi_lanes > 4) {
194 		drm_dbg_kms(&dev_priv->drm,
195 			    "invalid fdi lane config on pipe %c: %i lanes\n",
196 			    pipe_name(pipe), pipe_config->fdi_lanes);
197 		return -EINVAL;
198 	}
199 
200 	if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {
201 		if (pipe_config->fdi_lanes > 2) {
202 			drm_dbg_kms(&dev_priv->drm,
203 				    "only 2 lanes on haswell, required: %i lanes\n",
204 				    pipe_config->fdi_lanes);
205 			return -EINVAL;
206 		} else {
207 			return 0;
208 		}
209 	}
210 
211 	if (INTEL_NUM_PIPES(dev_priv) == 2)
212 		return 0;
213 
214 	/* Ivybridge 3 pipe is really complicated */
215 	switch (pipe) {
216 	case PIPE_A:
217 		return 0;
218 	case PIPE_B:
219 		if (pipe_config->fdi_lanes <= 2)
220 			return 0;
221 
222 		other_crtc = intel_crtc_for_pipe(dev_priv, PIPE_C);
223 		other_crtc_state =
224 			intel_atomic_get_crtc_state(state, other_crtc);
225 		if (IS_ERR(other_crtc_state))
226 			return PTR_ERR(other_crtc_state);
227 
228 		if (pipe_required_fdi_lanes(other_crtc_state) > 0) {
229 			drm_dbg_kms(&dev_priv->drm,
230 				    "invalid shared fdi lane config on pipe %c: %i lanes\n",
231 				    pipe_name(pipe), pipe_config->fdi_lanes);
232 			return -EINVAL;
233 		}
234 		return 0;
235 	case PIPE_C:
236 		if (pipe_config->fdi_lanes > 2) {
237 			drm_dbg_kms(&dev_priv->drm,
238 				    "only 2 lanes on pipe %c: required %i lanes\n",
239 				    pipe_name(pipe), pipe_config->fdi_lanes);
240 			return -EINVAL;
241 		}
242 
243 		other_crtc = intel_crtc_for_pipe(dev_priv, PIPE_B);
244 		other_crtc_state =
245 			intel_atomic_get_crtc_state(state, other_crtc);
246 		if (IS_ERR(other_crtc_state))
247 			return PTR_ERR(other_crtc_state);
248 
249 		if (pipe_required_fdi_lanes(other_crtc_state) > 2) {
250 			drm_dbg_kms(&dev_priv->drm,
251 				    "fdi link B uses too many lanes to enable link C\n");
252 
253 			*pipe_to_reduce = PIPE_B;
254 
255 			return -EINVAL;
256 		}
257 		return 0;
258 	default:
259 		MISSING_CASE(pipe);
260 		return 0;
261 	}
262 }
263 
264 void intel_fdi_pll_freq_update(struct drm_i915_private *i915)
265 {
266 	if (IS_IRONLAKE(i915)) {
267 		u32 fdi_pll_clk =
268 			intel_de_read(i915, FDI_PLL_BIOS_0) & FDI_PLL_FB_CLOCK_MASK;
269 
270 		i915->display.fdi.pll_freq = (fdi_pll_clk + 2) * 10000;
271 	} else if (IS_SANDYBRIDGE(i915) || IS_IVYBRIDGE(i915)) {
272 		i915->display.fdi.pll_freq = 270000;
273 	} else {
274 		return;
275 	}
276 
277 	drm_dbg(&i915->drm, "FDI PLL freq=%d\n", i915->display.fdi.pll_freq);
278 }
279 
280 int intel_fdi_link_freq(struct drm_i915_private *i915,
281 			const struct intel_crtc_state *pipe_config)
282 {
283 	if (HAS_DDI(i915))
284 		return pipe_config->port_clock; /* SPLL */
285 	else
286 		return i915->display.fdi.pll_freq;
287 }
288 
289 /**
290  * intel_fdi_compute_pipe_bpp - compute pipe bpp limited by max link bpp
291  * @crtc_state: the crtc state
292  *
293  * Compute the pipe bpp limited by the CRTC's maximum link bpp. Encoders can
294  * call this function during state computation in the simple case where the
295  * link bpp will always match the pipe bpp. This is the case for all non-DP
296  * encoders, while DP encoders will use a link bpp lower than pipe bpp in case
297  * of DSC compression.
298  *
299  * Returns %true in case of success, %false if pipe bpp would need to be
300  * reduced below its valid range.
301  */
302 bool intel_fdi_compute_pipe_bpp(struct intel_crtc_state *crtc_state)
303 {
304 	int pipe_bpp = min(crtc_state->pipe_bpp,
305 			   to_bpp_int(crtc_state->max_link_bpp_x16));
306 
307 	pipe_bpp = rounddown(pipe_bpp, 2 * 3);
308 
309 	if (pipe_bpp < 6 * 3)
310 		return false;
311 
312 	crtc_state->pipe_bpp = pipe_bpp;
313 
314 	return true;
315 }
316 
317 int ilk_fdi_compute_config(struct intel_crtc *crtc,
318 			   struct intel_crtc_state *pipe_config)
319 {
320 	struct drm_device *dev = crtc->base.dev;
321 	struct drm_i915_private *i915 = to_i915(dev);
322 	const struct drm_display_mode *adjusted_mode = &pipe_config->hw.adjusted_mode;
323 	int lane, link_bw, fdi_dotclock;
324 
325 	/* FDI is a binary signal running at ~2.7GHz, encoding
326 	 * each output octet as 10 bits. The actual frequency
327 	 * is stored as a divider into a 100MHz clock, and the
328 	 * mode pixel clock is stored in units of 1KHz.
329 	 * Hence the bw of each lane in terms of the mode signal
330 	 * is:
331 	 */
332 	link_bw = intel_fdi_link_freq(i915, pipe_config);
333 
334 	fdi_dotclock = adjusted_mode->crtc_clock;
335 
336 	lane = ilk_get_lanes_required(fdi_dotclock, link_bw,
337 				      pipe_config->pipe_bpp);
338 
339 	pipe_config->fdi_lanes = lane;
340 
341 	intel_link_compute_m_n(pipe_config->pipe_bpp, lane, fdi_dotclock,
342 			       link_bw, &pipe_config->fdi_m_n, false);
343 
344 	return 0;
345 }
346 
347 static int intel_fdi_atomic_check_bw(struct intel_atomic_state *state,
348 				     struct intel_crtc *crtc,
349 				     struct intel_crtc_state *pipe_config,
350 				     struct intel_link_bw_limits *limits)
351 {
352 	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
353 	enum pipe pipe_to_reduce;
354 	int ret;
355 
356 	ret = ilk_check_fdi_lanes(&i915->drm, crtc->pipe, pipe_config,
357 				  &pipe_to_reduce);
358 	if (ret != -EINVAL)
359 		return ret;
360 
361 	ret = intel_link_bw_reduce_bpp(state, limits,
362 				       BIT(pipe_to_reduce),
363 				       "FDI link BW");
364 
365 	return ret ? : -EAGAIN;
366 }
367 
368 /**
369  * intel_fdi_atomic_check_link - check all modeset FDI link configuration
370  * @state: intel atomic state
371  * @limits: link BW limits
372  *
373  * Check the link configuration for all modeset FDI outputs. If the
374  * configuration is invalid @limits will be updated if possible to
375  * reduce the total BW, after which the configuration for all CRTCs in
376  * @state must be recomputed with the updated @limits.
377  *
378  * Returns:
379  *   - 0 if the confugration is valid
380  *   - %-EAGAIN, if the configuration is invalid and @limits got updated
381  *     with fallback values with which the configuration of all CRTCs
382  *     in @state must be recomputed
383  *   - Other negative error, if the configuration is invalid without a
384  *     fallback possibility, or the check failed for another reason
385  */
386 int intel_fdi_atomic_check_link(struct intel_atomic_state *state,
387 				struct intel_link_bw_limits *limits)
388 {
389 	struct intel_crtc *crtc;
390 	struct intel_crtc_state *crtc_state;
391 	int i;
392 
393 	for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
394 		int ret;
395 
396 		if (!crtc_state->has_pch_encoder ||
397 		    !intel_crtc_needs_modeset(crtc_state) ||
398 		    !crtc_state->hw.enable)
399 			continue;
400 
401 		ret = intel_fdi_atomic_check_bw(state, crtc, crtc_state, limits);
402 		if (ret)
403 			return ret;
404 	}
405 
406 	return 0;
407 }
408 
409 static void cpt_set_fdi_bc_bifurcation(struct drm_i915_private *dev_priv, bool enable)
410 {
411 	u32 temp;
412 
413 	temp = intel_de_read(dev_priv, SOUTH_CHICKEN1);
414 	if (!!(temp & FDI_BC_BIFURCATION_SELECT) == enable)
415 		return;
416 
417 	drm_WARN_ON(&dev_priv->drm,
418 		    intel_de_read(dev_priv, FDI_RX_CTL(PIPE_B)) &
419 		    FDI_RX_ENABLE);
420 	drm_WARN_ON(&dev_priv->drm,
421 		    intel_de_read(dev_priv, FDI_RX_CTL(PIPE_C)) &
422 		    FDI_RX_ENABLE);
423 
424 	temp &= ~FDI_BC_BIFURCATION_SELECT;
425 	if (enable)
426 		temp |= FDI_BC_BIFURCATION_SELECT;
427 
428 	drm_dbg_kms(&dev_priv->drm, "%sabling fdi C rx\n",
429 		    enable ? "en" : "dis");
430 	intel_de_write(dev_priv, SOUTH_CHICKEN1, temp);
431 	intel_de_posting_read(dev_priv, SOUTH_CHICKEN1);
432 }
433 
434 static void ivb_update_fdi_bc_bifurcation(const struct intel_crtc_state *crtc_state)
435 {
436 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
437 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
438 
439 	switch (crtc->pipe) {
440 	case PIPE_A:
441 		break;
442 	case PIPE_B:
443 		if (crtc_state->fdi_lanes > 2)
444 			cpt_set_fdi_bc_bifurcation(dev_priv, false);
445 		else
446 			cpt_set_fdi_bc_bifurcation(dev_priv, true);
447 
448 		break;
449 	case PIPE_C:
450 		cpt_set_fdi_bc_bifurcation(dev_priv, true);
451 
452 		break;
453 	default:
454 		MISSING_CASE(crtc->pipe);
455 	}
456 }
457 
458 void intel_fdi_normal_train(struct intel_crtc *crtc)
459 {
460 	struct drm_device *dev = crtc->base.dev;
461 	struct drm_i915_private *dev_priv = to_i915(dev);
462 	enum pipe pipe = crtc->pipe;
463 	i915_reg_t reg;
464 	u32 temp;
465 
466 	/* enable normal train */
467 	reg = FDI_TX_CTL(pipe);
468 	temp = intel_de_read(dev_priv, reg);
469 	if (IS_IVYBRIDGE(dev_priv)) {
470 		temp &= ~FDI_LINK_TRAIN_NONE_IVB;
471 		temp |= FDI_LINK_TRAIN_NONE_IVB | FDI_TX_ENHANCE_FRAME_ENABLE;
472 	} else {
473 		temp &= ~FDI_LINK_TRAIN_NONE;
474 		temp |= FDI_LINK_TRAIN_NONE | FDI_TX_ENHANCE_FRAME_ENABLE;
475 	}
476 	intel_de_write(dev_priv, reg, temp);
477 
478 	reg = FDI_RX_CTL(pipe);
479 	temp = intel_de_read(dev_priv, reg);
480 	if (HAS_PCH_CPT(dev_priv)) {
481 		temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
482 		temp |= FDI_LINK_TRAIN_NORMAL_CPT;
483 	} else {
484 		temp &= ~FDI_LINK_TRAIN_NONE;
485 		temp |= FDI_LINK_TRAIN_NONE;
486 	}
487 	intel_de_write(dev_priv, reg, temp | FDI_RX_ENHANCE_FRAME_ENABLE);
488 
489 	/* wait one idle pattern time */
490 	intel_de_posting_read(dev_priv, reg);
491 	udelay(1000);
492 
493 	/* IVB wants error correction enabled */
494 	if (IS_IVYBRIDGE(dev_priv))
495 		intel_de_rmw(dev_priv, reg, 0, FDI_FS_ERRC_ENABLE | FDI_FE_ERRC_ENABLE);
496 }
497 
498 /* The FDI link training functions for ILK/Ibexpeak. */
499 static void ilk_fdi_link_train(struct intel_crtc *crtc,
500 			       const struct intel_crtc_state *crtc_state)
501 {
502 	struct drm_device *dev = crtc->base.dev;
503 	struct drm_i915_private *dev_priv = to_i915(dev);
504 	enum pipe pipe = crtc->pipe;
505 	i915_reg_t reg;
506 	u32 temp, tries;
507 
508 	/*
509 	 * Write the TU size bits before fdi link training, so that error
510 	 * detection works.
511 	 */
512 	intel_de_write(dev_priv, FDI_RX_TUSIZE1(pipe),
513 		       intel_de_read(dev_priv, PIPE_DATA_M1(pipe)) & TU_SIZE_MASK);
514 
515 	/* FDI needs bits from pipe first */
516 	assert_transcoder_enabled(dev_priv, crtc_state->cpu_transcoder);
517 
518 	/* Train 1: umask FDI RX Interrupt symbol_lock and bit_lock bit
519 	   for train result */
520 	reg = FDI_RX_IMR(pipe);
521 	temp = intel_de_read(dev_priv, reg);
522 	temp &= ~FDI_RX_SYMBOL_LOCK;
523 	temp &= ~FDI_RX_BIT_LOCK;
524 	intel_de_write(dev_priv, reg, temp);
525 	intel_de_read(dev_priv, reg);
526 	udelay(150);
527 
528 	/* enable CPU FDI TX and PCH FDI RX */
529 	reg = FDI_TX_CTL(pipe);
530 	temp = intel_de_read(dev_priv, reg);
531 	temp &= ~FDI_DP_PORT_WIDTH_MASK;
532 	temp |= FDI_DP_PORT_WIDTH(crtc_state->fdi_lanes);
533 	temp &= ~FDI_LINK_TRAIN_NONE;
534 	temp |= FDI_LINK_TRAIN_PATTERN_1;
535 	intel_de_write(dev_priv, reg, temp | FDI_TX_ENABLE);
536 
537 	reg = FDI_RX_CTL(pipe);
538 	temp = intel_de_read(dev_priv, reg);
539 	temp &= ~FDI_LINK_TRAIN_NONE;
540 	temp |= FDI_LINK_TRAIN_PATTERN_1;
541 	intel_de_write(dev_priv, reg, temp | FDI_RX_ENABLE);
542 
543 	intel_de_posting_read(dev_priv, reg);
544 	udelay(150);
545 
546 	/* Ironlake workaround, enable clock pointer after FDI enable*/
547 	intel_de_write(dev_priv, FDI_RX_CHICKEN(pipe),
548 		       FDI_RX_PHASE_SYNC_POINTER_OVR);
549 	intel_de_write(dev_priv, FDI_RX_CHICKEN(pipe),
550 		       FDI_RX_PHASE_SYNC_POINTER_OVR | FDI_RX_PHASE_SYNC_POINTER_EN);
551 
552 	reg = FDI_RX_IIR(pipe);
553 	for (tries = 0; tries < 5; tries++) {
554 		temp = intel_de_read(dev_priv, reg);
555 		drm_dbg_kms(&dev_priv->drm, "FDI_RX_IIR 0x%x\n", temp);
556 
557 		if ((temp & FDI_RX_BIT_LOCK)) {
558 			drm_dbg_kms(&dev_priv->drm, "FDI train 1 done.\n");
559 			intel_de_write(dev_priv, reg, temp | FDI_RX_BIT_LOCK);
560 			break;
561 		}
562 	}
563 	if (tries == 5)
564 		drm_err(&dev_priv->drm, "FDI train 1 fail!\n");
565 
566 	/* Train 2 */
567 	intel_de_rmw(dev_priv, FDI_TX_CTL(pipe),
568 		     FDI_LINK_TRAIN_NONE, FDI_LINK_TRAIN_PATTERN_2);
569 	intel_de_rmw(dev_priv, FDI_RX_CTL(pipe),
570 		     FDI_LINK_TRAIN_NONE, FDI_LINK_TRAIN_PATTERN_2);
571 	intel_de_posting_read(dev_priv, FDI_RX_CTL(pipe));
572 	udelay(150);
573 
574 	reg = FDI_RX_IIR(pipe);
575 	for (tries = 0; tries < 5; tries++) {
576 		temp = intel_de_read(dev_priv, reg);
577 		drm_dbg_kms(&dev_priv->drm, "FDI_RX_IIR 0x%x\n", temp);
578 
579 		if (temp & FDI_RX_SYMBOL_LOCK) {
580 			intel_de_write(dev_priv, reg,
581 				       temp | FDI_RX_SYMBOL_LOCK);
582 			drm_dbg_kms(&dev_priv->drm, "FDI train 2 done.\n");
583 			break;
584 		}
585 	}
586 	if (tries == 5)
587 		drm_err(&dev_priv->drm, "FDI train 2 fail!\n");
588 
589 	drm_dbg_kms(&dev_priv->drm, "FDI train done\n");
590 
591 }
592 
593 static const int snb_b_fdi_train_param[] = {
594 	FDI_LINK_TRAIN_400MV_0DB_SNB_B,
595 	FDI_LINK_TRAIN_400MV_6DB_SNB_B,
596 	FDI_LINK_TRAIN_600MV_3_5DB_SNB_B,
597 	FDI_LINK_TRAIN_800MV_0DB_SNB_B,
598 };
599 
600 /* The FDI link training functions for SNB/Cougarpoint. */
601 static void gen6_fdi_link_train(struct intel_crtc *crtc,
602 				const struct intel_crtc_state *crtc_state)
603 {
604 	struct drm_device *dev = crtc->base.dev;
605 	struct drm_i915_private *dev_priv = to_i915(dev);
606 	enum pipe pipe = crtc->pipe;
607 	i915_reg_t reg;
608 	u32 temp, i, retry;
609 
610 	/*
611 	 * Write the TU size bits before fdi link training, so that error
612 	 * detection works.
613 	 */
614 	intel_de_write(dev_priv, FDI_RX_TUSIZE1(pipe),
615 		       intel_de_read(dev_priv, PIPE_DATA_M1(pipe)) & TU_SIZE_MASK);
616 
617 	/* Train 1: umask FDI RX Interrupt symbol_lock and bit_lock bit
618 	   for train result */
619 	reg = FDI_RX_IMR(pipe);
620 	temp = intel_de_read(dev_priv, reg);
621 	temp &= ~FDI_RX_SYMBOL_LOCK;
622 	temp &= ~FDI_RX_BIT_LOCK;
623 	intel_de_write(dev_priv, reg, temp);
624 
625 	intel_de_posting_read(dev_priv, reg);
626 	udelay(150);
627 
628 	/* enable CPU FDI TX and PCH FDI RX */
629 	reg = FDI_TX_CTL(pipe);
630 	temp = intel_de_read(dev_priv, reg);
631 	temp &= ~FDI_DP_PORT_WIDTH_MASK;
632 	temp |= FDI_DP_PORT_WIDTH(crtc_state->fdi_lanes);
633 	temp &= ~FDI_LINK_TRAIN_NONE;
634 	temp |= FDI_LINK_TRAIN_PATTERN_1;
635 	temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
636 	/* SNB-B */
637 	temp |= FDI_LINK_TRAIN_400MV_0DB_SNB_B;
638 	intel_de_write(dev_priv, reg, temp | FDI_TX_ENABLE);
639 
640 	intel_de_write(dev_priv, FDI_RX_MISC(pipe),
641 		       FDI_RX_TP1_TO_TP2_48 | FDI_RX_FDI_DELAY_90);
642 
643 	reg = FDI_RX_CTL(pipe);
644 	temp = intel_de_read(dev_priv, reg);
645 	if (HAS_PCH_CPT(dev_priv)) {
646 		temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
647 		temp |= FDI_LINK_TRAIN_PATTERN_1_CPT;
648 	} else {
649 		temp &= ~FDI_LINK_TRAIN_NONE;
650 		temp |= FDI_LINK_TRAIN_PATTERN_1;
651 	}
652 	intel_de_write(dev_priv, reg, temp | FDI_RX_ENABLE);
653 
654 	intel_de_posting_read(dev_priv, reg);
655 	udelay(150);
656 
657 	for (i = 0; i < 4; i++) {
658 		intel_de_rmw(dev_priv, FDI_TX_CTL(pipe),
659 			     FDI_LINK_TRAIN_VOL_EMP_MASK, snb_b_fdi_train_param[i]);
660 		intel_de_posting_read(dev_priv, FDI_TX_CTL(pipe));
661 		udelay(500);
662 
663 		for (retry = 0; retry < 5; retry++) {
664 			reg = FDI_RX_IIR(pipe);
665 			temp = intel_de_read(dev_priv, reg);
666 			drm_dbg_kms(&dev_priv->drm, "FDI_RX_IIR 0x%x\n", temp);
667 			if (temp & FDI_RX_BIT_LOCK) {
668 				intel_de_write(dev_priv, reg,
669 					       temp | FDI_RX_BIT_LOCK);
670 				drm_dbg_kms(&dev_priv->drm,
671 					    "FDI train 1 done.\n");
672 				break;
673 			}
674 			udelay(50);
675 		}
676 		if (retry < 5)
677 			break;
678 	}
679 	if (i == 4)
680 		drm_err(&dev_priv->drm, "FDI train 1 fail!\n");
681 
682 	/* Train 2 */
683 	reg = FDI_TX_CTL(pipe);
684 	temp = intel_de_read(dev_priv, reg);
685 	temp &= ~FDI_LINK_TRAIN_NONE;
686 	temp |= FDI_LINK_TRAIN_PATTERN_2;
687 	if (IS_SANDYBRIDGE(dev_priv)) {
688 		temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
689 		/* SNB-B */
690 		temp |= FDI_LINK_TRAIN_400MV_0DB_SNB_B;
691 	}
692 	intel_de_write(dev_priv, reg, temp);
693 
694 	reg = FDI_RX_CTL(pipe);
695 	temp = intel_de_read(dev_priv, reg);
696 	if (HAS_PCH_CPT(dev_priv)) {
697 		temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
698 		temp |= FDI_LINK_TRAIN_PATTERN_2_CPT;
699 	} else {
700 		temp &= ~FDI_LINK_TRAIN_NONE;
701 		temp |= FDI_LINK_TRAIN_PATTERN_2;
702 	}
703 	intel_de_write(dev_priv, reg, temp);
704 
705 	intel_de_posting_read(dev_priv, reg);
706 	udelay(150);
707 
708 	for (i = 0; i < 4; i++) {
709 		intel_de_rmw(dev_priv, FDI_TX_CTL(pipe),
710 			     FDI_LINK_TRAIN_VOL_EMP_MASK, snb_b_fdi_train_param[i]);
711 		intel_de_posting_read(dev_priv, FDI_TX_CTL(pipe));
712 		udelay(500);
713 
714 		for (retry = 0; retry < 5; retry++) {
715 			reg = FDI_RX_IIR(pipe);
716 			temp = intel_de_read(dev_priv, reg);
717 			drm_dbg_kms(&dev_priv->drm, "FDI_RX_IIR 0x%x\n", temp);
718 			if (temp & FDI_RX_SYMBOL_LOCK) {
719 				intel_de_write(dev_priv, reg,
720 					       temp | FDI_RX_SYMBOL_LOCK);
721 				drm_dbg_kms(&dev_priv->drm,
722 					    "FDI train 2 done.\n");
723 				break;
724 			}
725 			udelay(50);
726 		}
727 		if (retry < 5)
728 			break;
729 	}
730 	if (i == 4)
731 		drm_err(&dev_priv->drm, "FDI train 2 fail!\n");
732 
733 	drm_dbg_kms(&dev_priv->drm, "FDI train done.\n");
734 }
735 
736 /* Manual link training for Ivy Bridge A0 parts */
737 static void ivb_manual_fdi_link_train(struct intel_crtc *crtc,
738 				      const struct intel_crtc_state *crtc_state)
739 {
740 	struct drm_device *dev = crtc->base.dev;
741 	struct drm_i915_private *dev_priv = to_i915(dev);
742 	enum pipe pipe = crtc->pipe;
743 	i915_reg_t reg;
744 	u32 temp, i, j;
745 
746 	ivb_update_fdi_bc_bifurcation(crtc_state);
747 
748 	/*
749 	 * Write the TU size bits before fdi link training, so that error
750 	 * detection works.
751 	 */
752 	intel_de_write(dev_priv, FDI_RX_TUSIZE1(pipe),
753 		       intel_de_read(dev_priv, PIPE_DATA_M1(pipe)) & TU_SIZE_MASK);
754 
755 	/* Train 1: umask FDI RX Interrupt symbol_lock and bit_lock bit
756 	   for train result */
757 	reg = FDI_RX_IMR(pipe);
758 	temp = intel_de_read(dev_priv, reg);
759 	temp &= ~FDI_RX_SYMBOL_LOCK;
760 	temp &= ~FDI_RX_BIT_LOCK;
761 	intel_de_write(dev_priv, reg, temp);
762 
763 	intel_de_posting_read(dev_priv, reg);
764 	udelay(150);
765 
766 	drm_dbg_kms(&dev_priv->drm, "FDI_RX_IIR before link train 0x%x\n",
767 		    intel_de_read(dev_priv, FDI_RX_IIR(pipe)));
768 
769 	/* Try each vswing and preemphasis setting twice before moving on */
770 	for (j = 0; j < ARRAY_SIZE(snb_b_fdi_train_param) * 2; j++) {
771 		/* disable first in case we need to retry */
772 		reg = FDI_TX_CTL(pipe);
773 		temp = intel_de_read(dev_priv, reg);
774 		temp &= ~(FDI_LINK_TRAIN_AUTO | FDI_LINK_TRAIN_NONE_IVB);
775 		temp &= ~FDI_TX_ENABLE;
776 		intel_de_write(dev_priv, reg, temp);
777 
778 		reg = FDI_RX_CTL(pipe);
779 		temp = intel_de_read(dev_priv, reg);
780 		temp &= ~FDI_LINK_TRAIN_AUTO;
781 		temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
782 		temp &= ~FDI_RX_ENABLE;
783 		intel_de_write(dev_priv, reg, temp);
784 
785 		/* enable CPU FDI TX and PCH FDI RX */
786 		reg = FDI_TX_CTL(pipe);
787 		temp = intel_de_read(dev_priv, reg);
788 		temp &= ~FDI_DP_PORT_WIDTH_MASK;
789 		temp |= FDI_DP_PORT_WIDTH(crtc_state->fdi_lanes);
790 		temp |= FDI_LINK_TRAIN_PATTERN_1_IVB;
791 		temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
792 		temp |= snb_b_fdi_train_param[j/2];
793 		temp |= FDI_COMPOSITE_SYNC;
794 		intel_de_write(dev_priv, reg, temp | FDI_TX_ENABLE);
795 
796 		intel_de_write(dev_priv, FDI_RX_MISC(pipe),
797 			       FDI_RX_TP1_TO_TP2_48 | FDI_RX_FDI_DELAY_90);
798 
799 		reg = FDI_RX_CTL(pipe);
800 		temp = intel_de_read(dev_priv, reg);
801 		temp |= FDI_LINK_TRAIN_PATTERN_1_CPT;
802 		temp |= FDI_COMPOSITE_SYNC;
803 		intel_de_write(dev_priv, reg, temp | FDI_RX_ENABLE);
804 
805 		intel_de_posting_read(dev_priv, reg);
806 		udelay(1); /* should be 0.5us */
807 
808 		for (i = 0; i < 4; i++) {
809 			reg = FDI_RX_IIR(pipe);
810 			temp = intel_de_read(dev_priv, reg);
811 			drm_dbg_kms(&dev_priv->drm, "FDI_RX_IIR 0x%x\n", temp);
812 
813 			if (temp & FDI_RX_BIT_LOCK ||
814 			    (intel_de_read(dev_priv, reg) & FDI_RX_BIT_LOCK)) {
815 				intel_de_write(dev_priv, reg,
816 					       temp | FDI_RX_BIT_LOCK);
817 				drm_dbg_kms(&dev_priv->drm,
818 					    "FDI train 1 done, level %i.\n",
819 					    i);
820 				break;
821 			}
822 			udelay(1); /* should be 0.5us */
823 		}
824 		if (i == 4) {
825 			drm_dbg_kms(&dev_priv->drm,
826 				    "FDI train 1 fail on vswing %d\n", j / 2);
827 			continue;
828 		}
829 
830 		/* Train 2 */
831 		intel_de_rmw(dev_priv, FDI_TX_CTL(pipe),
832 			     FDI_LINK_TRAIN_NONE_IVB,
833 			     FDI_LINK_TRAIN_PATTERN_2_IVB);
834 		intel_de_rmw(dev_priv, FDI_RX_CTL(pipe),
835 			     FDI_LINK_TRAIN_PATTERN_MASK_CPT,
836 			     FDI_LINK_TRAIN_PATTERN_2_CPT);
837 		intel_de_posting_read(dev_priv, FDI_RX_CTL(pipe));
838 		udelay(2); /* should be 1.5us */
839 
840 		for (i = 0; i < 4; i++) {
841 			reg = FDI_RX_IIR(pipe);
842 			temp = intel_de_read(dev_priv, reg);
843 			drm_dbg_kms(&dev_priv->drm, "FDI_RX_IIR 0x%x\n", temp);
844 
845 			if (temp & FDI_RX_SYMBOL_LOCK ||
846 			    (intel_de_read(dev_priv, reg) & FDI_RX_SYMBOL_LOCK)) {
847 				intel_de_write(dev_priv, reg,
848 					       temp | FDI_RX_SYMBOL_LOCK);
849 				drm_dbg_kms(&dev_priv->drm,
850 					    "FDI train 2 done, level %i.\n",
851 					    i);
852 				goto train_done;
853 			}
854 			udelay(2); /* should be 1.5us */
855 		}
856 		if (i == 4)
857 			drm_dbg_kms(&dev_priv->drm,
858 				    "FDI train 2 fail on vswing %d\n", j / 2);
859 	}
860 
861 train_done:
862 	drm_dbg_kms(&dev_priv->drm, "FDI train done.\n");
863 }
864 
865 /* Starting with Haswell, different DDI ports can work in FDI mode for
866  * connection to the PCH-located connectors. For this, it is necessary to train
867  * both the DDI port and PCH receiver for the desired DDI buffer settings.
868  *
869  * The recommended port to work in FDI mode is DDI E, which we use here. Also,
870  * please note that when FDI mode is active on DDI E, it shares 2 lines with
871  * DDI A (which is used for eDP)
872  */
873 void hsw_fdi_link_train(struct intel_encoder *encoder,
874 			const struct intel_crtc_state *crtc_state)
875 {
876 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
877 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
878 	u32 temp, i, rx_ctl_val;
879 	int n_entries;
880 
881 	encoder->get_buf_trans(encoder, crtc_state, &n_entries);
882 
883 	hsw_prepare_dp_ddi_buffers(encoder, crtc_state);
884 
885 	/* Set the FDI_RX_MISC pwrdn lanes and the 2 workarounds listed at the
886 	 * mode set "sequence for CRT port" document:
887 	 * - TP1 to TP2 time with the default value
888 	 * - FDI delay to 90h
889 	 *
890 	 * WaFDIAutoLinkSetTimingOverrride:hsw
891 	 */
892 	intel_de_write(dev_priv, FDI_RX_MISC(PIPE_A),
893 		       FDI_RX_PWRDN_LANE1_VAL(2) |
894 		       FDI_RX_PWRDN_LANE0_VAL(2) |
895 		       FDI_RX_TP1_TO_TP2_48 |
896 		       FDI_RX_FDI_DELAY_90);
897 
898 	/* Enable the PCH Receiver FDI PLL */
899 	rx_ctl_val = dev_priv->display.fdi.rx_config | FDI_RX_ENHANCE_FRAME_ENABLE |
900 		     FDI_RX_PLL_ENABLE |
901 		     FDI_DP_PORT_WIDTH(crtc_state->fdi_lanes);
902 	intel_de_write(dev_priv, FDI_RX_CTL(PIPE_A), rx_ctl_val);
903 	intel_de_posting_read(dev_priv, FDI_RX_CTL(PIPE_A));
904 	udelay(220);
905 
906 	/* Switch from Rawclk to PCDclk */
907 	rx_ctl_val |= FDI_PCDCLK;
908 	intel_de_write(dev_priv, FDI_RX_CTL(PIPE_A), rx_ctl_val);
909 
910 	/* Configure Port Clock Select */
911 	drm_WARN_ON(&dev_priv->drm, crtc_state->shared_dpll->info->id != DPLL_ID_SPLL);
912 	intel_ddi_enable_clock(encoder, crtc_state);
913 
914 	/* Start the training iterating through available voltages and emphasis,
915 	 * testing each value twice. */
916 	for (i = 0; i < n_entries * 2; i++) {
917 		/* Configure DP_TP_CTL with auto-training */
918 		intel_de_write(dev_priv, DP_TP_CTL(PORT_E),
919 			       DP_TP_CTL_FDI_AUTOTRAIN |
920 			       DP_TP_CTL_ENHANCED_FRAME_ENABLE |
921 			       DP_TP_CTL_LINK_TRAIN_PAT1 |
922 			       DP_TP_CTL_ENABLE);
923 
924 		/* Configure and enable DDI_BUF_CTL for DDI E with next voltage.
925 		 * DDI E does not support port reversal, the functionality is
926 		 * achieved on the PCH side in FDI_RX_CTL, so no need to set the
927 		 * port reversal bit */
928 		intel_de_write(dev_priv, DDI_BUF_CTL(PORT_E),
929 			       DDI_BUF_CTL_ENABLE |
930 			       ((crtc_state->fdi_lanes - 1) << 1) |
931 			       DDI_BUF_TRANS_SELECT(i / 2));
932 		intel_de_posting_read(dev_priv, DDI_BUF_CTL(PORT_E));
933 
934 		udelay(600);
935 
936 		/* Program PCH FDI Receiver TU */
937 		intel_de_write(dev_priv, FDI_RX_TUSIZE1(PIPE_A), TU_SIZE(64));
938 
939 		/* Enable PCH FDI Receiver with auto-training */
940 		rx_ctl_val |= FDI_RX_ENABLE | FDI_LINK_TRAIN_AUTO;
941 		intel_de_write(dev_priv, FDI_RX_CTL(PIPE_A), rx_ctl_val);
942 		intel_de_posting_read(dev_priv, FDI_RX_CTL(PIPE_A));
943 
944 		/* Wait for FDI receiver lane calibration */
945 		udelay(30);
946 
947 		/* Unset FDI_RX_MISC pwrdn lanes */
948 		intel_de_rmw(dev_priv, FDI_RX_MISC(PIPE_A),
949 			     FDI_RX_PWRDN_LANE1_MASK | FDI_RX_PWRDN_LANE0_MASK, 0);
950 		intel_de_posting_read(dev_priv, FDI_RX_MISC(PIPE_A));
951 
952 		/* Wait for FDI auto training time */
953 		udelay(5);
954 
955 		temp = intel_de_read(dev_priv, DP_TP_STATUS(PORT_E));
956 		if (temp & DP_TP_STATUS_AUTOTRAIN_DONE) {
957 			drm_dbg_kms(&dev_priv->drm,
958 				    "FDI link training done on step %d\n", i);
959 			break;
960 		}
961 
962 		/*
963 		 * Leave things enabled even if we failed to train FDI.
964 		 * Results in less fireworks from the state checker.
965 		 */
966 		if (i == n_entries * 2 - 1) {
967 			drm_err(&dev_priv->drm, "FDI link training failed!\n");
968 			break;
969 		}
970 
971 		rx_ctl_val &= ~FDI_RX_ENABLE;
972 		intel_de_write(dev_priv, FDI_RX_CTL(PIPE_A), rx_ctl_val);
973 		intel_de_posting_read(dev_priv, FDI_RX_CTL(PIPE_A));
974 
975 		intel_de_rmw(dev_priv, DDI_BUF_CTL(PORT_E), DDI_BUF_CTL_ENABLE, 0);
976 		intel_de_posting_read(dev_priv, DDI_BUF_CTL(PORT_E));
977 
978 		/* Disable DP_TP_CTL and FDI_RX_CTL and retry */
979 		intel_de_rmw(dev_priv, DP_TP_CTL(PORT_E), DP_TP_CTL_ENABLE, 0);
980 		intel_de_posting_read(dev_priv, DP_TP_CTL(PORT_E));
981 
982 		intel_wait_ddi_buf_idle(dev_priv, PORT_E);
983 
984 		/* Reset FDI_RX_MISC pwrdn lanes */
985 		intel_de_rmw(dev_priv, FDI_RX_MISC(PIPE_A),
986 			     FDI_RX_PWRDN_LANE1_MASK | FDI_RX_PWRDN_LANE0_MASK,
987 			     FDI_RX_PWRDN_LANE1_VAL(2) | FDI_RX_PWRDN_LANE0_VAL(2));
988 		intel_de_posting_read(dev_priv, FDI_RX_MISC(PIPE_A));
989 	}
990 
991 	/* Enable normal pixel sending for FDI */
992 	intel_de_write(dev_priv, DP_TP_CTL(PORT_E),
993 		       DP_TP_CTL_FDI_AUTOTRAIN |
994 		       DP_TP_CTL_LINK_TRAIN_NORMAL |
995 		       DP_TP_CTL_ENHANCED_FRAME_ENABLE |
996 		       DP_TP_CTL_ENABLE);
997 }
998 
999 void hsw_fdi_disable(struct intel_encoder *encoder)
1000 {
1001 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
1002 
1003 	/*
1004 	 * Bspec lists this as both step 13 (before DDI_BUF_CTL disable)
1005 	 * and step 18 (after clearing PORT_CLK_SEL). Based on a BUN,
1006 	 * step 13 is the correct place for it. Step 18 is where it was
1007 	 * originally before the BUN.
1008 	 */
1009 	intel_de_rmw(dev_priv, FDI_RX_CTL(PIPE_A), FDI_RX_ENABLE, 0);
1010 	intel_de_rmw(dev_priv, DDI_BUF_CTL(PORT_E), DDI_BUF_CTL_ENABLE, 0);
1011 	intel_wait_ddi_buf_idle(dev_priv, PORT_E);
1012 	intel_ddi_disable_clock(encoder);
1013 	intel_de_rmw(dev_priv, FDI_RX_MISC(PIPE_A),
1014 		     FDI_RX_PWRDN_LANE1_MASK | FDI_RX_PWRDN_LANE0_MASK,
1015 		     FDI_RX_PWRDN_LANE1_VAL(2) | FDI_RX_PWRDN_LANE0_VAL(2));
1016 	intel_de_rmw(dev_priv, FDI_RX_CTL(PIPE_A), FDI_PCDCLK, 0);
1017 	intel_de_rmw(dev_priv, FDI_RX_CTL(PIPE_A), FDI_RX_PLL_ENABLE, 0);
1018 }
1019 
1020 void ilk_fdi_pll_enable(const struct intel_crtc_state *crtc_state)
1021 {
1022 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
1023 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
1024 	enum pipe pipe = crtc->pipe;
1025 	i915_reg_t reg;
1026 	u32 temp;
1027 
1028 	/* enable PCH FDI RX PLL, wait warmup plus DMI latency */
1029 	reg = FDI_RX_CTL(pipe);
1030 	temp = intel_de_read(dev_priv, reg);
1031 	temp &= ~(FDI_DP_PORT_WIDTH_MASK | (0x7 << 16));
1032 	temp |= FDI_DP_PORT_WIDTH(crtc_state->fdi_lanes);
1033 	temp |= (intel_de_read(dev_priv, TRANSCONF(pipe)) & TRANSCONF_BPC_MASK) << 11;
1034 	intel_de_write(dev_priv, reg, temp | FDI_RX_PLL_ENABLE);
1035 
1036 	intel_de_posting_read(dev_priv, reg);
1037 	udelay(200);
1038 
1039 	/* Switch from Rawclk to PCDclk */
1040 	intel_de_rmw(dev_priv, reg, 0, FDI_PCDCLK);
1041 	intel_de_posting_read(dev_priv, reg);
1042 	udelay(200);
1043 
1044 	/* Enable CPU FDI TX PLL, always on for Ironlake */
1045 	reg = FDI_TX_CTL(pipe);
1046 	temp = intel_de_read(dev_priv, reg);
1047 	if ((temp & FDI_TX_PLL_ENABLE) == 0) {
1048 		intel_de_write(dev_priv, reg, temp | FDI_TX_PLL_ENABLE);
1049 
1050 		intel_de_posting_read(dev_priv, reg);
1051 		udelay(100);
1052 	}
1053 }
1054 
1055 void ilk_fdi_pll_disable(struct intel_crtc *crtc)
1056 {
1057 	struct drm_device *dev = crtc->base.dev;
1058 	struct drm_i915_private *dev_priv = to_i915(dev);
1059 	enum pipe pipe = crtc->pipe;
1060 
1061 	/* Switch from PCDclk to Rawclk */
1062 	intel_de_rmw(dev_priv, FDI_RX_CTL(pipe), FDI_PCDCLK, 0);
1063 
1064 	/* Disable CPU FDI TX PLL */
1065 	intel_de_rmw(dev_priv, FDI_TX_CTL(pipe), FDI_TX_PLL_ENABLE, 0);
1066 	intel_de_posting_read(dev_priv, FDI_TX_CTL(pipe));
1067 	udelay(100);
1068 
1069 	/* Wait for the clocks to turn off. */
1070 	intel_de_rmw(dev_priv, FDI_RX_CTL(pipe), FDI_RX_PLL_ENABLE, 0);
1071 	intel_de_posting_read(dev_priv, FDI_RX_CTL(pipe));
1072 	udelay(100);
1073 }
1074 
1075 void ilk_fdi_disable(struct intel_crtc *crtc)
1076 {
1077 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
1078 	enum pipe pipe = crtc->pipe;
1079 	i915_reg_t reg;
1080 	u32 temp;
1081 
1082 	/* disable CPU FDI tx and PCH FDI rx */
1083 	intel_de_rmw(dev_priv, FDI_TX_CTL(pipe), FDI_TX_ENABLE, 0);
1084 	intel_de_posting_read(dev_priv, FDI_TX_CTL(pipe));
1085 
1086 	reg = FDI_RX_CTL(pipe);
1087 	temp = intel_de_read(dev_priv, reg);
1088 	temp &= ~(0x7 << 16);
1089 	temp |= (intel_de_read(dev_priv, TRANSCONF(pipe)) & TRANSCONF_BPC_MASK) << 11;
1090 	intel_de_write(dev_priv, reg, temp & ~FDI_RX_ENABLE);
1091 
1092 	intel_de_posting_read(dev_priv, reg);
1093 	udelay(100);
1094 
1095 	/* Ironlake workaround, disable clock pointer after downing FDI */
1096 	if (HAS_PCH_IBX(dev_priv))
1097 		intel_de_write(dev_priv, FDI_RX_CHICKEN(pipe),
1098 			       FDI_RX_PHASE_SYNC_POINTER_OVR);
1099 
1100 	/* still set train pattern 1 */
1101 	intel_de_rmw(dev_priv, FDI_TX_CTL(pipe),
1102 		     FDI_LINK_TRAIN_NONE, FDI_LINK_TRAIN_PATTERN_1);
1103 
1104 	reg = FDI_RX_CTL(pipe);
1105 	temp = intel_de_read(dev_priv, reg);
1106 	if (HAS_PCH_CPT(dev_priv)) {
1107 		temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
1108 		temp |= FDI_LINK_TRAIN_PATTERN_1_CPT;
1109 	} else {
1110 		temp &= ~FDI_LINK_TRAIN_NONE;
1111 		temp |= FDI_LINK_TRAIN_PATTERN_1;
1112 	}
1113 	/* BPC in FDI rx is consistent with that in TRANSCONF */
1114 	temp &= ~(0x07 << 16);
1115 	temp |= (intel_de_read(dev_priv, TRANSCONF(pipe)) & TRANSCONF_BPC_MASK) << 11;
1116 	intel_de_write(dev_priv, reg, temp);
1117 
1118 	intel_de_posting_read(dev_priv, reg);
1119 	udelay(100);
1120 }
1121 
1122 static const struct intel_fdi_funcs ilk_funcs = {
1123 	.fdi_link_train = ilk_fdi_link_train,
1124 };
1125 
1126 static const struct intel_fdi_funcs gen6_funcs = {
1127 	.fdi_link_train = gen6_fdi_link_train,
1128 };
1129 
1130 static const struct intel_fdi_funcs ivb_funcs = {
1131 	.fdi_link_train = ivb_manual_fdi_link_train,
1132 };
1133 
1134 void
1135 intel_fdi_init_hook(struct drm_i915_private *dev_priv)
1136 {
1137 	if (IS_IRONLAKE(dev_priv)) {
1138 		dev_priv->display.funcs.fdi = &ilk_funcs;
1139 	} else if (IS_SANDYBRIDGE(dev_priv)) {
1140 		dev_priv->display.funcs.fdi = &gen6_funcs;
1141 	} else if (IS_IVYBRIDGE(dev_priv)) {
1142 		/* FIXME: detect B0+ stepping and use auto training */
1143 		dev_priv->display.funcs.fdi = &ivb_funcs;
1144 	}
1145 }
1146