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1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2021 Intel Corporation
4 */
5
6#include "i915_reg.h"
7#include "intel_de.h"
8#include "intel_display_types.h"
9#include "intel_panel.h"
10#include "intel_pch_refclk.h"
11#include "intel_sbi.h"
12
13static void lpt_fdi_reset_mphy(struct drm_i915_private *dev_priv)
14{
15 intel_de_rmw(dev_priv, SOUTH_CHICKEN2, 0, FDI_MPHY_IOSFSB_RESET_CTL);
16
17 if (wait_for_us(intel_de_read(dev_priv, SOUTH_CHICKEN2) &
18 FDI_MPHY_IOSFSB_RESET_STATUS, 100))
19 drm_err(&dev_priv->drm, "FDI mPHY reset assert timeout\n");
20
21 intel_de_rmw(dev_priv, SOUTH_CHICKEN2, FDI_MPHY_IOSFSB_RESET_CTL, 0);
22
23 if (wait_for_us((intel_de_read(dev_priv, SOUTH_CHICKEN2) &
24 FDI_MPHY_IOSFSB_RESET_STATUS) == 0, 100))
25 drm_err(&dev_priv->drm, "FDI mPHY reset de-assert timeout\n");
26}
27
28/* WaMPhyProgramming:hsw */
29static void lpt_fdi_program_mphy(struct drm_i915_private *dev_priv)
30{
31 u32 tmp;
32
33 lpt_fdi_reset_mphy(dev_priv);
34
35 tmp = intel_sbi_read(dev_priv, 0x8008, SBI_MPHY);
36 tmp &= ~(0xFF << 24);
37 tmp |= (0x12 << 24);
38 intel_sbi_write(dev_priv, 0x8008, tmp, SBI_MPHY);
39
40 tmp = intel_sbi_read(dev_priv, 0x2008, SBI_MPHY);
41 tmp |= (1 << 11);
42 intel_sbi_write(dev_priv, 0x2008, tmp, SBI_MPHY);
43
44 tmp = intel_sbi_read(dev_priv, 0x2108, SBI_MPHY);
45 tmp |= (1 << 11);
46 intel_sbi_write(dev_priv, 0x2108, tmp, SBI_MPHY);
47
48 tmp = intel_sbi_read(dev_priv, 0x206C, SBI_MPHY);
49 tmp |= (1 << 24) | (1 << 21) | (1 << 18);
50 intel_sbi_write(dev_priv, 0x206C, tmp, SBI_MPHY);
51
52 tmp = intel_sbi_read(dev_priv, 0x216C, SBI_MPHY);
53 tmp |= (1 << 24) | (1 << 21) | (1 << 18);
54 intel_sbi_write(dev_priv, 0x216C, tmp, SBI_MPHY);
55
56 tmp = intel_sbi_read(dev_priv, 0x2080, SBI_MPHY);
57 tmp &= ~(7 << 13);
58 tmp |= (5 << 13);
59 intel_sbi_write(dev_priv, 0x2080, tmp, SBI_MPHY);
60
61 tmp = intel_sbi_read(dev_priv, 0x2180, SBI_MPHY);
62 tmp &= ~(7 << 13);
63 tmp |= (5 << 13);
64 intel_sbi_write(dev_priv, 0x2180, tmp, SBI_MPHY);
65
66 tmp = intel_sbi_read(dev_priv, 0x208C, SBI_MPHY);
67 tmp &= ~0xFF;
68 tmp |= 0x1C;
69 intel_sbi_write(dev_priv, 0x208C, tmp, SBI_MPHY);
70
71 tmp = intel_sbi_read(dev_priv, 0x218C, SBI_MPHY);
72 tmp &= ~0xFF;
73 tmp |= 0x1C;
74 intel_sbi_write(dev_priv, 0x218C, tmp, SBI_MPHY);
75
76 tmp = intel_sbi_read(dev_priv, 0x2098, SBI_MPHY);
77 tmp &= ~(0xFF << 16);
78 tmp |= (0x1C << 16);
79 intel_sbi_write(dev_priv, 0x2098, tmp, SBI_MPHY);
80
81 tmp = intel_sbi_read(dev_priv, 0x2198, SBI_MPHY);
82 tmp &= ~(0xFF << 16);
83 tmp |= (0x1C << 16);
84 intel_sbi_write(dev_priv, 0x2198, tmp, SBI_MPHY);
85
86 tmp = intel_sbi_read(dev_priv, 0x20C4, SBI_MPHY);
87 tmp |= (1 << 27);
88 intel_sbi_write(dev_priv, 0x20C4, tmp, SBI_MPHY);
89
90 tmp = intel_sbi_read(dev_priv, 0x21C4, SBI_MPHY);
91 tmp |= (1 << 27);
92 intel_sbi_write(dev_priv, 0x21C4, tmp, SBI_MPHY);
93
94 tmp = intel_sbi_read(dev_priv, 0x20EC, SBI_MPHY);
95 tmp &= ~(0xF << 28);
96 tmp |= (4 << 28);
97 intel_sbi_write(dev_priv, 0x20EC, tmp, SBI_MPHY);
98
99 tmp = intel_sbi_read(dev_priv, 0x21EC, SBI_MPHY);
100 tmp &= ~(0xF << 28);
101 tmp |= (4 << 28);
102 intel_sbi_write(dev_priv, 0x21EC, tmp, SBI_MPHY);
103}
104
105void lpt_disable_iclkip(struct drm_i915_private *dev_priv)
106{
107 u32 temp;
108
109 intel_de_write(dev_priv, PIXCLK_GATE, PIXCLK_GATE_GATE);
110
111 mutex_lock(&dev_priv->sb_lock);
112
113 temp = intel_sbi_read(dev_priv, SBI_SSCCTL6, SBI_ICLK);
114 temp |= SBI_SSCCTL_DISABLE;
115 intel_sbi_write(dev_priv, SBI_SSCCTL6, temp, SBI_ICLK);
116
117 mutex_unlock(&dev_priv->sb_lock);
118}
119
120struct iclkip_params {
121 u32 iclk_virtual_root_freq;
122 u32 iclk_pi_range;
123 u32 divsel, phaseinc, auxdiv, phasedir, desired_divisor;
124};
125
126static void iclkip_params_init(struct iclkip_params *p)
127{
128 memset(p, 0, sizeof(*p));
129
130 p->iclk_virtual_root_freq = 172800 * 1000;
131 p->iclk_pi_range = 64;
132}
133
134static int lpt_iclkip_freq(struct iclkip_params *p)
135{
136 return DIV_ROUND_CLOSEST(p->iclk_virtual_root_freq,
137 p->desired_divisor << p->auxdiv);
138}
139
140static void lpt_compute_iclkip(struct iclkip_params *p, int clock)
141{
142 iclkip_params_init(p);
143
144 /* The iCLK virtual clock root frequency is in MHz,
145 * but the adjusted_mode->crtc_clock in KHz. To get the
146 * divisors, it is necessary to divide one by another, so we
147 * convert the virtual clock precision to KHz here for higher
148 * precision.
149 */
150 for (p->auxdiv = 0; p->auxdiv < 2; p->auxdiv++) {
151 p->desired_divisor = DIV_ROUND_CLOSEST(p->iclk_virtual_root_freq,
152 clock << p->auxdiv);
153 p->divsel = (p->desired_divisor / p->iclk_pi_range) - 2;
154 p->phaseinc = p->desired_divisor % p->iclk_pi_range;
155
156 /*
157 * Near 20MHz is a corner case which is
158 * out of range for the 7-bit divisor
159 */
160 if (p->divsel <= 0x7f)
161 break;
162 }
163}
164
165int lpt_iclkip(const struct intel_crtc_state *crtc_state)
166{
167 struct iclkip_params p;
168
169 lpt_compute_iclkip(&p, crtc_state->hw.adjusted_mode.crtc_clock);
170
171 return lpt_iclkip_freq(&p);
172}
173
174/* Program iCLKIP clock to the desired frequency */
175void lpt_program_iclkip(const struct intel_crtc_state *crtc_state)
176{
177 struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
178 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
179 int clock = crtc_state->hw.adjusted_mode.crtc_clock;
180 struct iclkip_params p;
181 u32 temp;
182
183 lpt_disable_iclkip(dev_priv);
184
185 lpt_compute_iclkip(&p, clock);
186 drm_WARN_ON(&dev_priv->drm, lpt_iclkip_freq(&p) != clock);
187
188 /* This should not happen with any sane values */
189 drm_WARN_ON(&dev_priv->drm, SBI_SSCDIVINTPHASE_DIVSEL(p.divsel) &
190 ~SBI_SSCDIVINTPHASE_DIVSEL_MASK);
191 drm_WARN_ON(&dev_priv->drm, SBI_SSCDIVINTPHASE_DIR(p.phasedir) &
192 ~SBI_SSCDIVINTPHASE_INCVAL_MASK);
193
194 drm_dbg_kms(&dev_priv->drm,
195 "iCLKIP clock: found settings for %dKHz refresh rate: auxdiv=%x, divsel=%x, phasedir=%x, phaseinc=%x\n",
196 clock, p.auxdiv, p.divsel, p.phasedir, p.phaseinc);
197
198 mutex_lock(&dev_priv->sb_lock);
199
200 /* Program SSCDIVINTPHASE6 */
201 temp = intel_sbi_read(dev_priv, SBI_SSCDIVINTPHASE6, SBI_ICLK);
202 temp &= ~SBI_SSCDIVINTPHASE_DIVSEL_MASK;
203 temp |= SBI_SSCDIVINTPHASE_DIVSEL(p.divsel);
204 temp &= ~SBI_SSCDIVINTPHASE_INCVAL_MASK;
205 temp |= SBI_SSCDIVINTPHASE_INCVAL(p.phaseinc);
206 temp |= SBI_SSCDIVINTPHASE_DIR(p.phasedir);
207 temp |= SBI_SSCDIVINTPHASE_PROPAGATE;
208 intel_sbi_write(dev_priv, SBI_SSCDIVINTPHASE6, temp, SBI_ICLK);
209
210 /* Program SSCAUXDIV */
211 temp = intel_sbi_read(dev_priv, SBI_SSCAUXDIV6, SBI_ICLK);
212 temp &= ~SBI_SSCAUXDIV_FINALDIV2SEL(1);
213 temp |= SBI_SSCAUXDIV_FINALDIV2SEL(p.auxdiv);
214 intel_sbi_write(dev_priv, SBI_SSCAUXDIV6, temp, SBI_ICLK);
215
216 /* Enable modulator and associated divider */
217 temp = intel_sbi_read(dev_priv, SBI_SSCCTL6, SBI_ICLK);
218 temp &= ~SBI_SSCCTL_DISABLE;
219 intel_sbi_write(dev_priv, SBI_SSCCTL6, temp, SBI_ICLK);
220
221 mutex_unlock(&dev_priv->sb_lock);
222
223 /* Wait for initialization time */
224 udelay(24);
225
226 intel_de_write(dev_priv, PIXCLK_GATE, PIXCLK_GATE_UNGATE);
227}
228
229int lpt_get_iclkip(struct drm_i915_private *dev_priv)
230{
231 struct iclkip_params p;
232 u32 temp;
233
234 if ((intel_de_read(dev_priv, PIXCLK_GATE) & PIXCLK_GATE_UNGATE) == 0)
235 return 0;
236
237 iclkip_params_init(&p);
238
239 mutex_lock(&dev_priv->sb_lock);
240
241 temp = intel_sbi_read(dev_priv, SBI_SSCCTL6, SBI_ICLK);
242 if (temp & SBI_SSCCTL_DISABLE) {
243 mutex_unlock(&dev_priv->sb_lock);
244 return 0;
245 }
246
247 temp = intel_sbi_read(dev_priv, SBI_SSCDIVINTPHASE6, SBI_ICLK);
248 p.divsel = (temp & SBI_SSCDIVINTPHASE_DIVSEL_MASK) >>
249 SBI_SSCDIVINTPHASE_DIVSEL_SHIFT;
250 p.phaseinc = (temp & SBI_SSCDIVINTPHASE_INCVAL_MASK) >>
251 SBI_SSCDIVINTPHASE_INCVAL_SHIFT;
252
253 temp = intel_sbi_read(dev_priv, SBI_SSCAUXDIV6, SBI_ICLK);
254 p.auxdiv = (temp & SBI_SSCAUXDIV_FINALDIV2SEL_MASK) >>
255 SBI_SSCAUXDIV_FINALDIV2SEL_SHIFT;
256
257 mutex_unlock(&dev_priv->sb_lock);
258
259 p.desired_divisor = (p.divsel + 2) * p.iclk_pi_range + p.phaseinc;
260
261 return lpt_iclkip_freq(&p);
262}
263
264/* Implements 3 different sequences from BSpec chapter "Display iCLK
265 * Programming" based on the parameters passed:
266 * - Sequence to enable CLKOUT_DP
267 * - Sequence to enable CLKOUT_DP without spread
268 * - Sequence to enable CLKOUT_DP for FDI usage and configure PCH FDI I/O
269 */
270static void lpt_enable_clkout_dp(struct drm_i915_private *dev_priv,
271 bool with_spread, bool with_fdi)
272{
273 u32 reg, tmp;
274
275 if (drm_WARN(&dev_priv->drm, with_fdi && !with_spread,
276 "FDI requires downspread\n"))
277 with_spread = true;
278 if (drm_WARN(&dev_priv->drm, HAS_PCH_LPT_LP(dev_priv) &&
279 with_fdi, "LP PCH doesn't have FDI\n"))
280 with_fdi = false;
281
282 mutex_lock(&dev_priv->sb_lock);
283
284 tmp = intel_sbi_read(dev_priv, SBI_SSCCTL, SBI_ICLK);
285 tmp &= ~SBI_SSCCTL_DISABLE;
286 tmp |= SBI_SSCCTL_PATHALT;
287 intel_sbi_write(dev_priv, SBI_SSCCTL, tmp, SBI_ICLK);
288
289 udelay(24);
290
291 if (with_spread) {
292 tmp = intel_sbi_read(dev_priv, SBI_SSCCTL, SBI_ICLK);
293 tmp &= ~SBI_SSCCTL_PATHALT;
294 intel_sbi_write(dev_priv, SBI_SSCCTL, tmp, SBI_ICLK);
295
296 if (with_fdi)
297 lpt_fdi_program_mphy(dev_priv);
298 }
299
300 reg = HAS_PCH_LPT_LP(dev_priv) ? SBI_GEN0 : SBI_DBUFF0;
301 tmp = intel_sbi_read(dev_priv, reg, SBI_ICLK);
302 tmp |= SBI_GEN0_CFG_BUFFENABLE_DISABLE;
303 intel_sbi_write(dev_priv, reg, tmp, SBI_ICLK);
304
305 mutex_unlock(&dev_priv->sb_lock);
306}
307
308/* Sequence to disable CLKOUT_DP */
309void lpt_disable_clkout_dp(struct drm_i915_private *dev_priv)
310{
311 u32 reg, tmp;
312
313 mutex_lock(&dev_priv->sb_lock);
314
315 reg = HAS_PCH_LPT_LP(dev_priv) ? SBI_GEN0 : SBI_DBUFF0;
316 tmp = intel_sbi_read(dev_priv, reg, SBI_ICLK);
317 tmp &= ~SBI_GEN0_CFG_BUFFENABLE_DISABLE;
318 intel_sbi_write(dev_priv, reg, tmp, SBI_ICLK);
319
320 tmp = intel_sbi_read(dev_priv, SBI_SSCCTL, SBI_ICLK);
321 if (!(tmp & SBI_SSCCTL_DISABLE)) {
322 if (!(tmp & SBI_SSCCTL_PATHALT)) {
323 tmp |= SBI_SSCCTL_PATHALT;
324 intel_sbi_write(dev_priv, SBI_SSCCTL, tmp, SBI_ICLK);
325 udelay(32);
326 }
327 tmp |= SBI_SSCCTL_DISABLE;
328 intel_sbi_write(dev_priv, SBI_SSCCTL, tmp, SBI_ICLK);
329 }
330
331 mutex_unlock(&dev_priv->sb_lock);
332}
333
334#define BEND_IDX(steps) ((50 + (steps)) / 5)
335
336static const u16 sscdivintphase[] = {
337 [BEND_IDX( 50)] = 0x3B23,
338 [BEND_IDX( 45)] = 0x3B23,
339 [BEND_IDX( 40)] = 0x3C23,
340 [BEND_IDX( 35)] = 0x3C23,
341 [BEND_IDX( 30)] = 0x3D23,
342 [BEND_IDX( 25)] = 0x3D23,
343 [BEND_IDX( 20)] = 0x3E23,
344 [BEND_IDX( 15)] = 0x3E23,
345 [BEND_IDX( 10)] = 0x3F23,
346 [BEND_IDX( 5)] = 0x3F23,
347 [BEND_IDX( 0)] = 0x0025,
348 [BEND_IDX( -5)] = 0x0025,
349 [BEND_IDX(-10)] = 0x0125,
350 [BEND_IDX(-15)] = 0x0125,
351 [BEND_IDX(-20)] = 0x0225,
352 [BEND_IDX(-25)] = 0x0225,
353 [BEND_IDX(-30)] = 0x0325,
354 [BEND_IDX(-35)] = 0x0325,
355 [BEND_IDX(-40)] = 0x0425,
356 [BEND_IDX(-45)] = 0x0425,
357 [BEND_IDX(-50)] = 0x0525,
358};
359
360/*
361 * Bend CLKOUT_DP
362 * steps -50 to 50 inclusive, in steps of 5
363 * < 0 slow down the clock, > 0 speed up the clock, 0 == no bend (135MHz)
364 * change in clock period = -(steps / 10) * 5.787 ps
365 */
366static void lpt_bend_clkout_dp(struct drm_i915_private *dev_priv, int steps)
367{
368 u32 tmp;
369 int idx = BEND_IDX(steps);
370
371 if (drm_WARN_ON(&dev_priv->drm, steps % 5 != 0))
372 return;
373
374 if (drm_WARN_ON(&dev_priv->drm, idx >= ARRAY_SIZE(sscdivintphase)))
375 return;
376
377 mutex_lock(&dev_priv->sb_lock);
378
379 if (steps % 10 != 0)
380 tmp = 0xAAAAAAAB;
381 else
382 tmp = 0x00000000;
383 intel_sbi_write(dev_priv, SBI_SSCDITHPHASE, tmp, SBI_ICLK);
384
385 tmp = intel_sbi_read(dev_priv, SBI_SSCDIVINTPHASE, SBI_ICLK);
386 tmp &= 0xffff0000;
387 tmp |= sscdivintphase[idx];
388 intel_sbi_write(dev_priv, SBI_SSCDIVINTPHASE, tmp, SBI_ICLK);
389
390 mutex_unlock(&dev_priv->sb_lock);
391}
392
393#undef BEND_IDX
394
395static bool spll_uses_pch_ssc(struct drm_i915_private *dev_priv)
396{
397 u32 fuse_strap = intel_de_read(dev_priv, FUSE_STRAP);
398 u32 ctl = intel_de_read(dev_priv, SPLL_CTL);
399
400 if ((ctl & SPLL_PLL_ENABLE) == 0)
401 return false;
402
403 if ((ctl & SPLL_REF_MASK) == SPLL_REF_MUXED_SSC &&
404 (fuse_strap & HSW_CPU_SSC_ENABLE) == 0)
405 return true;
406
407 if (IS_BROADWELL(dev_priv) &&
408 (ctl & SPLL_REF_MASK) == SPLL_REF_PCH_SSC_BDW)
409 return true;
410
411 return false;
412}
413
414static bool wrpll_uses_pch_ssc(struct drm_i915_private *dev_priv,
415 enum intel_dpll_id id)
416{
417 u32 fuse_strap = intel_de_read(dev_priv, FUSE_STRAP);
418 u32 ctl = intel_de_read(dev_priv, WRPLL_CTL(id));
419
420 if ((ctl & WRPLL_PLL_ENABLE) == 0)
421 return false;
422
423 if ((ctl & WRPLL_REF_MASK) == WRPLL_REF_PCH_SSC)
424 return true;
425
426 if ((IS_BROADWELL(dev_priv) || IS_HASWELL_ULT(dev_priv)) &&
427 (ctl & WRPLL_REF_MASK) == WRPLL_REF_MUXED_SSC_BDW &&
428 (fuse_strap & HSW_CPU_SSC_ENABLE) == 0)
429 return true;
430
431 return false;
432}
433
434static void lpt_init_pch_refclk(struct drm_i915_private *dev_priv)
435{
436 struct intel_encoder *encoder;
437 bool has_fdi = false;
438
439 for_each_intel_encoder(&dev_priv->drm, encoder) {
440 switch (encoder->type) {
441 case INTEL_OUTPUT_ANALOG:
442 has_fdi = true;
443 break;
444 default:
445 break;
446 }
447 }
448
449 /*
450 * The BIOS may have decided to use the PCH SSC
451 * reference so we must not disable it until the
452 * relevant PLLs have stopped relying on it. We'll
453 * just leave the PCH SSC reference enabled in case
454 * any active PLL is using it. It will get disabled
455 * after runtime suspend if we don't have FDI.
456 *
457 * TODO: Move the whole reference clock handling
458 * to the modeset sequence proper so that we can
459 * actually enable/disable/reconfigure these things
460 * safely. To do that we need to introduce a real
461 * clock hierarchy. That would also allow us to do
462 * clock bending finally.
463 */
464 dev_priv->display.dpll.pch_ssc_use = 0;
465
466 if (spll_uses_pch_ssc(dev_priv)) {
467 drm_dbg_kms(&dev_priv->drm, "SPLL using PCH SSC\n");
468 dev_priv->display.dpll.pch_ssc_use |= BIT(DPLL_ID_SPLL);
469 }
470
471 if (wrpll_uses_pch_ssc(dev_priv, DPLL_ID_WRPLL1)) {
472 drm_dbg_kms(&dev_priv->drm, "WRPLL1 using PCH SSC\n");
473 dev_priv->display.dpll.pch_ssc_use |= BIT(DPLL_ID_WRPLL1);
474 }
475
476 if (wrpll_uses_pch_ssc(dev_priv, DPLL_ID_WRPLL2)) {
477 drm_dbg_kms(&dev_priv->drm, "WRPLL2 using PCH SSC\n");
478 dev_priv->display.dpll.pch_ssc_use |= BIT(DPLL_ID_WRPLL2);
479 }
480
481 if (dev_priv->display.dpll.pch_ssc_use)
482 return;
483
484 if (has_fdi) {
485 lpt_bend_clkout_dp(dev_priv, 0);
486 lpt_enable_clkout_dp(dev_priv, true, true);
487 } else {
488 lpt_disable_clkout_dp(dev_priv);
489 }
490}
491
492static void ilk_init_pch_refclk(struct drm_i915_private *dev_priv)
493{
494 struct intel_display *display = &dev_priv->display;
495 struct intel_encoder *encoder;
496 struct intel_shared_dpll *pll;
497 int i;
498 u32 val, final;
499 bool has_lvds = false;
500 bool has_cpu_edp = false;
501 bool has_panel = false;
502 bool has_ck505 = false;
503 bool can_ssc = false;
504 bool using_ssc_source = false;
505
506 /* We need to take the global config into account */
507 for_each_intel_encoder(&dev_priv->drm, encoder) {
508 switch (encoder->type) {
509 case INTEL_OUTPUT_LVDS:
510 has_panel = true;
511 has_lvds = true;
512 break;
513 case INTEL_OUTPUT_EDP:
514 has_panel = true;
515 if (encoder->port == PORT_A)
516 has_cpu_edp = true;
517 break;
518 default:
519 break;
520 }
521 }
522
523 if (HAS_PCH_IBX(dev_priv)) {
524 has_ck505 = dev_priv->display.vbt.display_clock_mode;
525 can_ssc = has_ck505;
526 } else {
527 has_ck505 = false;
528 can_ssc = true;
529 }
530
531 /* Check if any DPLLs are using the SSC source */
532 for_each_shared_dpll(dev_priv, pll, i) {
533 u32 temp;
534
535 temp = intel_de_read(dev_priv, PCH_DPLL(pll->info->id));
536
537 if (!(temp & DPLL_VCO_ENABLE))
538 continue;
539
540 if ((temp & PLL_REF_INPUT_MASK) ==
541 PLLB_REF_INPUT_SPREADSPECTRUMIN) {
542 using_ssc_source = true;
543 break;
544 }
545 }
546
547 drm_dbg_kms(&dev_priv->drm,
548 "has_panel %d has_lvds %d has_ck505 %d using_ssc_source %d\n",
549 has_panel, has_lvds, has_ck505, using_ssc_source);
550
551 /* Ironlake: try to setup display ref clock before DPLL
552 * enabling. This is only under driver's control after
553 * PCH B stepping, previous chipset stepping should be
554 * ignoring this setting.
555 */
556 val = intel_de_read(dev_priv, PCH_DREF_CONTROL);
557
558 /* As we must carefully and slowly disable/enable each source in turn,
559 * compute the final state we want first and check if we need to
560 * make any changes at all.
561 */
562 final = val;
563 final &= ~DREF_NONSPREAD_SOURCE_MASK;
564 if (has_ck505)
565 final |= DREF_NONSPREAD_CK505_ENABLE;
566 else
567 final |= DREF_NONSPREAD_SOURCE_ENABLE;
568
569 final &= ~DREF_SSC_SOURCE_MASK;
570 final &= ~DREF_CPU_SOURCE_OUTPUT_MASK;
571 final &= ~DREF_SSC1_ENABLE;
572
573 if (has_panel) {
574 final |= DREF_SSC_SOURCE_ENABLE;
575
576 if (intel_panel_use_ssc(display) && can_ssc)
577 final |= DREF_SSC1_ENABLE;
578
579 if (has_cpu_edp) {
580 if (intel_panel_use_ssc(display) && can_ssc)
581 final |= DREF_CPU_SOURCE_OUTPUT_DOWNSPREAD;
582 else
583 final |= DREF_CPU_SOURCE_OUTPUT_NONSPREAD;
584 } else {
585 final |= DREF_CPU_SOURCE_OUTPUT_DISABLE;
586 }
587 } else if (using_ssc_source) {
588 final |= DREF_SSC_SOURCE_ENABLE;
589 final |= DREF_SSC1_ENABLE;
590 }
591
592 if (final == val)
593 return;
594
595 /* Always enable nonspread source */
596 val &= ~DREF_NONSPREAD_SOURCE_MASK;
597
598 if (has_ck505)
599 val |= DREF_NONSPREAD_CK505_ENABLE;
600 else
601 val |= DREF_NONSPREAD_SOURCE_ENABLE;
602
603 if (has_panel) {
604 val &= ~DREF_SSC_SOURCE_MASK;
605 val |= DREF_SSC_SOURCE_ENABLE;
606
607 /* SSC must be turned on before enabling the CPU output */
608 if (intel_panel_use_ssc(display) && can_ssc) {
609 drm_dbg_kms(&dev_priv->drm, "Using SSC on panel\n");
610 val |= DREF_SSC1_ENABLE;
611 } else {
612 val &= ~DREF_SSC1_ENABLE;
613 }
614
615 /* Get SSC going before enabling the outputs */
616 intel_de_write(dev_priv, PCH_DREF_CONTROL, val);
617 intel_de_posting_read(dev_priv, PCH_DREF_CONTROL);
618 udelay(200);
619
620 val &= ~DREF_CPU_SOURCE_OUTPUT_MASK;
621
622 /* Enable CPU source on CPU attached eDP */
623 if (has_cpu_edp) {
624 if (intel_panel_use_ssc(display) && can_ssc) {
625 drm_dbg_kms(&dev_priv->drm,
626 "Using SSC on eDP\n");
627 val |= DREF_CPU_SOURCE_OUTPUT_DOWNSPREAD;
628 } else {
629 val |= DREF_CPU_SOURCE_OUTPUT_NONSPREAD;
630 }
631 } else {
632 val |= DREF_CPU_SOURCE_OUTPUT_DISABLE;
633 }
634
635 intel_de_write(dev_priv, PCH_DREF_CONTROL, val);
636 intel_de_posting_read(dev_priv, PCH_DREF_CONTROL);
637 udelay(200);
638 } else {
639 drm_dbg_kms(&dev_priv->drm, "Disabling CPU source output\n");
640
641 val &= ~DREF_CPU_SOURCE_OUTPUT_MASK;
642
643 /* Turn off CPU output */
644 val |= DREF_CPU_SOURCE_OUTPUT_DISABLE;
645
646 intel_de_write(dev_priv, PCH_DREF_CONTROL, val);
647 intel_de_posting_read(dev_priv, PCH_DREF_CONTROL);
648 udelay(200);
649
650 if (!using_ssc_source) {
651 drm_dbg_kms(&dev_priv->drm, "Disabling SSC source\n");
652
653 /* Turn off the SSC source */
654 val &= ~DREF_SSC_SOURCE_MASK;
655 val |= DREF_SSC_SOURCE_DISABLE;
656
657 /* Turn off SSC1 */
658 val &= ~DREF_SSC1_ENABLE;
659
660 intel_de_write(dev_priv, PCH_DREF_CONTROL, val);
661 intel_de_posting_read(dev_priv, PCH_DREF_CONTROL);
662 udelay(200);
663 }
664 }
665
666 drm_WARN_ON(&dev_priv->drm, val != final);
667}
668
669/*
670 * Initialize reference clocks when the driver loads
671 */
672void intel_init_pch_refclk(struct drm_i915_private *dev_priv)
673{
674 if (HAS_PCH_IBX(dev_priv) || HAS_PCH_CPT(dev_priv))
675 ilk_init_pch_refclk(dev_priv);
676 else if (HAS_PCH_LPT(dev_priv))
677 lpt_init_pch_refclk(dev_priv);
678}