1 /*
2  * Copyright © 2013 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21  * DEALINGS IN THE SOFTWARE.
22  *
23  * Authors:
24  *	Shobhit Kumar <shobhit.kumar@intel.com>
25  *	Yogesh Mohan Marimuthu <yogesh.mohan.marimuthu@intel.com>
26  */
27 
28 #include <linux/kernel.h>
29 
30 #include "i915_drv.h"
31 #include "intel_de.h"
32 #include "intel_display_types.h"
33 #include "intel_dsi.h"
34 #include "intel_sideband.h"
35 
36 static const u16 lfsr_converts[] = {
37 	426, 469, 234, 373, 442, 221, 110, 311, 411,		/* 62 - 70 */
38 	461, 486, 243, 377, 188, 350, 175, 343, 427, 213,	/* 71 - 80 */
39 	106, 53, 282, 397, 454, 227, 113, 56, 284, 142,		/* 81 - 90 */
40 	71, 35, 273, 136, 324, 418, 465, 488, 500, 506		/* 91 - 100 */
41 };
42 
43 /* Get DSI clock from pixel clock */
44 static u32 dsi_clk_from_pclk(u32 pclk, enum mipi_dsi_pixel_format fmt,
45 			     int lane_count)
46 {
47 	u32 dsi_clk_khz;
48 	u32 bpp = mipi_dsi_pixel_format_to_bpp(fmt);
49 
50 	/* DSI data rate = pixel clock * bits per pixel / lane count
51 	   pixel clock is converted from KHz to Hz */
52 	dsi_clk_khz = DIV_ROUND_CLOSEST(pclk * bpp, lane_count);
53 
54 	return dsi_clk_khz;
55 }
56 
57 static int dsi_calc_mnp(struct drm_i915_private *dev_priv,
58 			struct intel_crtc_state *config,
59 			int target_dsi_clk)
60 {
61 	unsigned int m_min, m_max, p_min = 2, p_max = 6;
62 	unsigned int m, n, p;
63 	unsigned int calc_m, calc_p;
64 	int delta, ref_clk;
65 
66 	/* target_dsi_clk is expected in kHz */
67 	if (target_dsi_clk < 300000 || target_dsi_clk > 1150000) {
68 		drm_err(&dev_priv->drm, "DSI CLK Out of Range\n");
69 		return -ECHRNG;
70 	}
71 
72 	if (IS_CHERRYVIEW(dev_priv)) {
73 		ref_clk = 100000;
74 		n = 4;
75 		m_min = 70;
76 		m_max = 96;
77 	} else {
78 		ref_clk = 25000;
79 		n = 1;
80 		m_min = 62;
81 		m_max = 92;
82 	}
83 
84 	calc_p = p_min;
85 	calc_m = m_min;
86 	delta = abs(target_dsi_clk - (m_min * ref_clk) / (p_min * n));
87 
88 	for (m = m_min; m <= m_max && delta; m++) {
89 		for (p = p_min; p <= p_max && delta; p++) {
90 			/*
91 			 * Find the optimal m and p divisors with minimal delta
92 			 * +/- the required clock
93 			 */
94 			int calc_dsi_clk = (m * ref_clk) / (p * n);
95 			int d = abs(target_dsi_clk - calc_dsi_clk);
96 			if (d < delta) {
97 				delta = d;
98 				calc_m = m;
99 				calc_p = p;
100 			}
101 		}
102 	}
103 
104 	/* register has log2(N1), this works fine for powers of two */
105 	config->dsi_pll.ctrl = 1 << (DSI_PLL_P1_POST_DIV_SHIFT + calc_p - 2);
106 	config->dsi_pll.div =
107 		(ffs(n) - 1) << DSI_PLL_N1_DIV_SHIFT |
108 		(u32)lfsr_converts[calc_m - 62] << DSI_PLL_M1_DIV_SHIFT;
109 
110 	return 0;
111 }
112 
113 /*
114  * XXX: The muxing and gating is hard coded for now. Need to add support for
115  * sharing PLLs with two DSI outputs.
116  */
117 int vlv_dsi_pll_compute(struct intel_encoder *encoder,
118 			struct intel_crtc_state *config)
119 {
120 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
121 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
122 	int ret;
123 	u32 dsi_clk;
124 
125 	dsi_clk = dsi_clk_from_pclk(intel_dsi->pclk, intel_dsi->pixel_format,
126 				    intel_dsi->lane_count);
127 
128 	ret = dsi_calc_mnp(dev_priv, config, dsi_clk);
129 	if (ret) {
130 		drm_dbg_kms(&dev_priv->drm, "dsi_calc_mnp failed\n");
131 		return ret;
132 	}
133 
134 	if (intel_dsi->ports & (1 << PORT_A))
135 		config->dsi_pll.ctrl |= DSI_PLL_CLK_GATE_DSI0_DSIPLL;
136 
137 	if (intel_dsi->ports & (1 << PORT_C))
138 		config->dsi_pll.ctrl |= DSI_PLL_CLK_GATE_DSI1_DSIPLL;
139 
140 	config->dsi_pll.ctrl |= DSI_PLL_VCO_EN;
141 
142 	drm_dbg_kms(&dev_priv->drm, "dsi pll div %08x, ctrl %08x\n",
143 		    config->dsi_pll.div, config->dsi_pll.ctrl);
144 
145 	return 0;
146 }
147 
148 void vlv_dsi_pll_enable(struct intel_encoder *encoder,
149 			const struct intel_crtc_state *config)
150 {
151 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
152 
153 	drm_dbg_kms(&dev_priv->drm, "\n");
154 
155 	vlv_cck_get(dev_priv);
156 
157 	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, 0);
158 	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_DIVIDER, config->dsi_pll.div);
159 	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL,
160 		      config->dsi_pll.ctrl & ~DSI_PLL_VCO_EN);
161 
162 	/* wait at least 0.5 us after ungating before enabling VCO,
163 	 * allow hrtimer subsystem optimization by relaxing timing
164 	 */
165 	usleep_range(10, 50);
166 
167 	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, config->dsi_pll.ctrl);
168 
169 	if (wait_for(vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL) &
170 						DSI_PLL_LOCK, 20)) {
171 
172 		vlv_cck_put(dev_priv);
173 		drm_err(&dev_priv->drm, "DSI PLL lock failed\n");
174 		return;
175 	}
176 	vlv_cck_put(dev_priv);
177 
178 	drm_dbg_kms(&dev_priv->drm, "DSI PLL locked\n");
179 }
180 
181 void vlv_dsi_pll_disable(struct intel_encoder *encoder)
182 {
183 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
184 	u32 tmp;
185 
186 	drm_dbg_kms(&dev_priv->drm, "\n");
187 
188 	vlv_cck_get(dev_priv);
189 
190 	tmp = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL);
191 	tmp &= ~DSI_PLL_VCO_EN;
192 	tmp |= DSI_PLL_LDO_GATE;
193 	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, tmp);
194 
195 	vlv_cck_put(dev_priv);
196 }
197 
198 bool bxt_dsi_pll_is_enabled(struct drm_i915_private *dev_priv)
199 {
200 	bool enabled;
201 	u32 val;
202 	u32 mask;
203 
204 	mask = BXT_DSI_PLL_DO_ENABLE | BXT_DSI_PLL_LOCKED;
205 	val = intel_de_read(dev_priv, BXT_DSI_PLL_ENABLE);
206 	enabled = (val & mask) == mask;
207 
208 	if (!enabled)
209 		return false;
210 
211 	/*
212 	 * Dividers must be programmed with valid values. As per BSEPC, for
213 	 * GEMINLAKE only PORT A divider values are checked while for BXT
214 	 * both divider values are validated. Check this here for
215 	 * paranoia, since BIOS is known to misconfigure PLLs in this way at
216 	 * times, and since accessing DSI registers with invalid dividers
217 	 * causes a system hang.
218 	 */
219 	val = intel_de_read(dev_priv, BXT_DSI_PLL_CTL);
220 	if (IS_GEMINILAKE(dev_priv)) {
221 		if (!(val & BXT_DSIA_16X_MASK)) {
222 			drm_dbg(&dev_priv->drm,
223 				"Invalid PLL divider (%08x)\n", val);
224 			enabled = false;
225 		}
226 	} else {
227 		if (!(val & BXT_DSIA_16X_MASK) || !(val & BXT_DSIC_16X_MASK)) {
228 			drm_dbg(&dev_priv->drm,
229 				"Invalid PLL divider (%08x)\n", val);
230 			enabled = false;
231 		}
232 	}
233 
234 	return enabled;
235 }
236 
237 void bxt_dsi_pll_disable(struct intel_encoder *encoder)
238 {
239 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
240 	u32 val;
241 
242 	drm_dbg_kms(&dev_priv->drm, "\n");
243 
244 	val = intel_de_read(dev_priv, BXT_DSI_PLL_ENABLE);
245 	val &= ~BXT_DSI_PLL_DO_ENABLE;
246 	intel_de_write(dev_priv, BXT_DSI_PLL_ENABLE, val);
247 
248 	/*
249 	 * PLL lock should deassert within 200us.
250 	 * Wait up to 1ms before timing out.
251 	 */
252 	if (intel_de_wait_for_clear(dev_priv, BXT_DSI_PLL_ENABLE,
253 				    BXT_DSI_PLL_LOCKED, 1))
254 		drm_err(&dev_priv->drm,
255 			"Timeout waiting for PLL lock deassertion\n");
256 }
257 
258 u32 vlv_dsi_get_pclk(struct intel_encoder *encoder,
259 		     struct intel_crtc_state *config)
260 {
261 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
262 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
263 	int bpp = mipi_dsi_pixel_format_to_bpp(intel_dsi->pixel_format);
264 	u32 dsi_clock, pclk;
265 	u32 pll_ctl, pll_div;
266 	u32 m = 0, p = 0, n;
267 	int refclk = IS_CHERRYVIEW(dev_priv) ? 100000 : 25000;
268 	int i;
269 
270 	drm_dbg_kms(&dev_priv->drm, "\n");
271 
272 	vlv_cck_get(dev_priv);
273 	pll_ctl = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL);
274 	pll_div = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_DIVIDER);
275 	vlv_cck_put(dev_priv);
276 
277 	config->dsi_pll.ctrl = pll_ctl & ~DSI_PLL_LOCK;
278 	config->dsi_pll.div = pll_div;
279 
280 	/* mask out other bits and extract the P1 divisor */
281 	pll_ctl &= DSI_PLL_P1_POST_DIV_MASK;
282 	pll_ctl = pll_ctl >> (DSI_PLL_P1_POST_DIV_SHIFT - 2);
283 
284 	/* N1 divisor */
285 	n = (pll_div & DSI_PLL_N1_DIV_MASK) >> DSI_PLL_N1_DIV_SHIFT;
286 	n = 1 << n; /* register has log2(N1) */
287 
288 	/* mask out the other bits and extract the M1 divisor */
289 	pll_div &= DSI_PLL_M1_DIV_MASK;
290 	pll_div = pll_div >> DSI_PLL_M1_DIV_SHIFT;
291 
292 	while (pll_ctl) {
293 		pll_ctl = pll_ctl >> 1;
294 		p++;
295 	}
296 	p--;
297 
298 	if (!p) {
299 		drm_err(&dev_priv->drm, "wrong P1 divisor\n");
300 		return 0;
301 	}
302 
303 	for (i = 0; i < ARRAY_SIZE(lfsr_converts); i++) {
304 		if (lfsr_converts[i] == pll_div)
305 			break;
306 	}
307 
308 	if (i == ARRAY_SIZE(lfsr_converts)) {
309 		drm_err(&dev_priv->drm, "wrong m_seed programmed\n");
310 		return 0;
311 	}
312 
313 	m = i + 62;
314 
315 	dsi_clock = (m * refclk) / (p * n);
316 
317 	pclk = DIV_ROUND_CLOSEST(dsi_clock * intel_dsi->lane_count, bpp);
318 
319 	return pclk;
320 }
321 
322 u32 bxt_dsi_get_pclk(struct intel_encoder *encoder,
323 		     struct intel_crtc_state *config)
324 {
325 	u32 pclk;
326 	u32 dsi_clk;
327 	u32 dsi_ratio;
328 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
329 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
330 	int bpp = mipi_dsi_pixel_format_to_bpp(intel_dsi->pixel_format);
331 
332 	config->dsi_pll.ctrl = intel_de_read(dev_priv, BXT_DSI_PLL_CTL);
333 
334 	dsi_ratio = config->dsi_pll.ctrl & BXT_DSI_PLL_RATIO_MASK;
335 
336 	dsi_clk = (dsi_ratio * BXT_REF_CLOCK_KHZ) / 2;
337 
338 	pclk = DIV_ROUND_CLOSEST(dsi_clk * intel_dsi->lane_count, bpp);
339 
340 	drm_dbg(&dev_priv->drm, "Calculated pclk=%u\n", pclk);
341 	return pclk;
342 }
343 
344 void vlv_dsi_reset_clocks(struct intel_encoder *encoder, enum port port)
345 {
346 	u32 temp;
347 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
348 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
349 
350 	temp = intel_de_read(dev_priv, MIPI_CTRL(port));
351 	temp &= ~ESCAPE_CLOCK_DIVIDER_MASK;
352 	intel_de_write(dev_priv, MIPI_CTRL(port),
353 		       temp | intel_dsi->escape_clk_div << ESCAPE_CLOCK_DIVIDER_SHIFT);
354 }
355 
356 static void glk_dsi_program_esc_clock(struct drm_device *dev,
357 				   const struct intel_crtc_state *config)
358 {
359 	struct drm_i915_private *dev_priv = to_i915(dev);
360 	u32 dsi_rate = 0;
361 	u32 pll_ratio = 0;
362 	u32 ddr_clk = 0;
363 	u32 div1_value = 0;
364 	u32 div2_value = 0;
365 	u32 txesc1_div = 0;
366 	u32 txesc2_div = 0;
367 
368 	pll_ratio = config->dsi_pll.ctrl & BXT_DSI_PLL_RATIO_MASK;
369 
370 	dsi_rate = (BXT_REF_CLOCK_KHZ * pll_ratio) / 2;
371 
372 	ddr_clk = dsi_rate / 2;
373 
374 	/* Variable divider value */
375 	div1_value = DIV_ROUND_CLOSEST(ddr_clk, 20000);
376 
377 	/* Calculate TXESC1 divider */
378 	if (div1_value <= 10)
379 		txesc1_div = div1_value;
380 	else if ((div1_value > 10) && (div1_value <= 20))
381 		txesc1_div = DIV_ROUND_UP(div1_value, 2);
382 	else if ((div1_value > 20) && (div1_value <= 30))
383 		txesc1_div = DIV_ROUND_UP(div1_value, 4);
384 	else if ((div1_value > 30) && (div1_value <= 40))
385 		txesc1_div = DIV_ROUND_UP(div1_value, 6);
386 	else if ((div1_value > 40) && (div1_value <= 50))
387 		txesc1_div = DIV_ROUND_UP(div1_value, 8);
388 	else
389 		txesc1_div = 10;
390 
391 	/* Calculate TXESC2 divider */
392 	div2_value = DIV_ROUND_UP(div1_value, txesc1_div);
393 
394 	if (div2_value < 10)
395 		txesc2_div = div2_value;
396 	else
397 		txesc2_div = 10;
398 
399 	intel_de_write(dev_priv, MIPIO_TXESC_CLK_DIV1,
400 		       (1 << (txesc1_div - 1)) & GLK_TX_ESC_CLK_DIV1_MASK);
401 	intel_de_write(dev_priv, MIPIO_TXESC_CLK_DIV2,
402 		       (1 << (txesc2_div - 1)) & GLK_TX_ESC_CLK_DIV2_MASK);
403 }
404 
405 /* Program BXT Mipi clocks and dividers */
406 static void bxt_dsi_program_clocks(struct drm_device *dev, enum port port,
407 				   const struct intel_crtc_state *config)
408 {
409 	struct drm_i915_private *dev_priv = to_i915(dev);
410 	u32 tmp;
411 	u32 dsi_rate = 0;
412 	u32 pll_ratio = 0;
413 	u32 rx_div;
414 	u32 tx_div;
415 	u32 rx_div_upper;
416 	u32 rx_div_lower;
417 	u32 mipi_8by3_divider;
418 
419 	/* Clear old configurations */
420 	tmp = intel_de_read(dev_priv, BXT_MIPI_CLOCK_CTL);
421 	tmp &= ~(BXT_MIPI_TX_ESCLK_FIXDIV_MASK(port));
422 	tmp &= ~(BXT_MIPI_RX_ESCLK_UPPER_FIXDIV_MASK(port));
423 	tmp &= ~(BXT_MIPI_8X_BY3_DIVIDER_MASK(port));
424 	tmp &= ~(BXT_MIPI_RX_ESCLK_LOWER_FIXDIV_MASK(port));
425 
426 	/* Get the current DSI rate(actual) */
427 	pll_ratio = config->dsi_pll.ctrl & BXT_DSI_PLL_RATIO_MASK;
428 	dsi_rate = (BXT_REF_CLOCK_KHZ * pll_ratio) / 2;
429 
430 	/*
431 	 * tx clock should be <= 20MHz and the div value must be
432 	 * subtracted by 1 as per bspec
433 	 */
434 	tx_div = DIV_ROUND_UP(dsi_rate, 20000) - 1;
435 	/*
436 	 * rx clock should be <= 150MHz and the div value must be
437 	 * subtracted by 1 as per bspec
438 	 */
439 	rx_div = DIV_ROUND_UP(dsi_rate, 150000) - 1;
440 
441 	/*
442 	 * rx divider value needs to be updated in the
443 	 * two differnt bit fields in the register hence splitting the
444 	 * rx divider value accordingly
445 	 */
446 	rx_div_lower = rx_div & RX_DIVIDER_BIT_1_2;
447 	rx_div_upper = (rx_div & RX_DIVIDER_BIT_3_4) >> 2;
448 
449 	mipi_8by3_divider = 0x2;
450 
451 	tmp |= BXT_MIPI_8X_BY3_DIVIDER(port, mipi_8by3_divider);
452 	tmp |= BXT_MIPI_TX_ESCLK_DIVIDER(port, tx_div);
453 	tmp |= BXT_MIPI_RX_ESCLK_LOWER_DIVIDER(port, rx_div_lower);
454 	tmp |= BXT_MIPI_RX_ESCLK_UPPER_DIVIDER(port, rx_div_upper);
455 
456 	intel_de_write(dev_priv, BXT_MIPI_CLOCK_CTL, tmp);
457 }
458 
459 int bxt_dsi_pll_compute(struct intel_encoder *encoder,
460 			struct intel_crtc_state *config)
461 {
462 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
463 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
464 	u8 dsi_ratio, dsi_ratio_min, dsi_ratio_max;
465 	u32 dsi_clk;
466 
467 	dsi_clk = dsi_clk_from_pclk(intel_dsi->pclk, intel_dsi->pixel_format,
468 				    intel_dsi->lane_count);
469 
470 	/*
471 	 * From clock diagram, to get PLL ratio divider, divide double of DSI
472 	 * link rate (i.e., 2*8x=16x frequency value) by ref clock. Make sure to
473 	 * round 'up' the result
474 	 */
475 	dsi_ratio = DIV_ROUND_UP(dsi_clk * 2, BXT_REF_CLOCK_KHZ);
476 
477 	if (IS_BROXTON(dev_priv)) {
478 		dsi_ratio_min = BXT_DSI_PLL_RATIO_MIN;
479 		dsi_ratio_max = BXT_DSI_PLL_RATIO_MAX;
480 	} else {
481 		dsi_ratio_min = GLK_DSI_PLL_RATIO_MIN;
482 		dsi_ratio_max = GLK_DSI_PLL_RATIO_MAX;
483 	}
484 
485 	if (dsi_ratio < dsi_ratio_min || dsi_ratio > dsi_ratio_max) {
486 		drm_err(&dev_priv->drm,
487 			"Can't get a suitable ratio from DSI PLL ratios\n");
488 		return -ECHRNG;
489 	} else
490 		drm_dbg_kms(&dev_priv->drm, "DSI PLL calculation is Done!!\n");
491 
492 	/*
493 	 * Program DSI ratio and Select MIPIC and MIPIA PLL output as 8x
494 	 * Spec says both have to be programmed, even if one is not getting
495 	 * used. Configure MIPI_CLOCK_CTL dividers in modeset
496 	 */
497 	config->dsi_pll.ctrl = dsi_ratio | BXT_DSIA_16X_BY2 | BXT_DSIC_16X_BY2;
498 
499 	/* As per recommendation from hardware team,
500 	 * Prog PVD ratio =1 if dsi ratio <= 50
501 	 */
502 	if (IS_BROXTON(dev_priv) && dsi_ratio <= 50)
503 		config->dsi_pll.ctrl |= BXT_DSI_PLL_PVD_RATIO_1;
504 
505 	return 0;
506 }
507 
508 void bxt_dsi_pll_enable(struct intel_encoder *encoder,
509 			const struct intel_crtc_state *config)
510 {
511 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
512 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
513 	enum port port;
514 	u32 val;
515 
516 	drm_dbg_kms(&dev_priv->drm, "\n");
517 
518 	/* Configure PLL vales */
519 	intel_de_write(dev_priv, BXT_DSI_PLL_CTL, config->dsi_pll.ctrl);
520 	intel_de_posting_read(dev_priv, BXT_DSI_PLL_CTL);
521 
522 	/* Program TX, RX, Dphy clocks */
523 	if (IS_BROXTON(dev_priv)) {
524 		for_each_dsi_port(port, intel_dsi->ports)
525 			bxt_dsi_program_clocks(encoder->base.dev, port, config);
526 	} else {
527 		glk_dsi_program_esc_clock(encoder->base.dev, config);
528 	}
529 
530 	/* Enable DSI PLL */
531 	val = intel_de_read(dev_priv, BXT_DSI_PLL_ENABLE);
532 	val |= BXT_DSI_PLL_DO_ENABLE;
533 	intel_de_write(dev_priv, BXT_DSI_PLL_ENABLE, val);
534 
535 	/* Timeout and fail if PLL not locked */
536 	if (intel_de_wait_for_set(dev_priv, BXT_DSI_PLL_ENABLE,
537 				  BXT_DSI_PLL_LOCKED, 1)) {
538 		drm_err(&dev_priv->drm,
539 			"Timed out waiting for DSI PLL to lock\n");
540 		return;
541 	}
542 
543 	drm_dbg_kms(&dev_priv->drm, "DSI PLL locked\n");
544 }
545 
546 void bxt_dsi_reset_clocks(struct intel_encoder *encoder, enum port port)
547 {
548 	u32 tmp;
549 	struct drm_device *dev = encoder->base.dev;
550 	struct drm_i915_private *dev_priv = to_i915(dev);
551 
552 	/* Clear old configurations */
553 	if (IS_BROXTON(dev_priv)) {
554 		tmp = intel_de_read(dev_priv, BXT_MIPI_CLOCK_CTL);
555 		tmp &= ~(BXT_MIPI_TX_ESCLK_FIXDIV_MASK(port));
556 		tmp &= ~(BXT_MIPI_RX_ESCLK_UPPER_FIXDIV_MASK(port));
557 		tmp &= ~(BXT_MIPI_8X_BY3_DIVIDER_MASK(port));
558 		tmp &= ~(BXT_MIPI_RX_ESCLK_LOWER_FIXDIV_MASK(port));
559 		intel_de_write(dev_priv, BXT_MIPI_CLOCK_CTL, tmp);
560 	} else {
561 		tmp = intel_de_read(dev_priv, MIPIO_TXESC_CLK_DIV1);
562 		tmp &= ~GLK_TX_ESC_CLK_DIV1_MASK;
563 		intel_de_write(dev_priv, MIPIO_TXESC_CLK_DIV1, tmp);
564 
565 		tmp = intel_de_read(dev_priv, MIPIO_TXESC_CLK_DIV2);
566 		tmp &= ~GLK_TX_ESC_CLK_DIV2_MASK;
567 		intel_de_write(dev_priv, MIPIO_TXESC_CLK_DIV2, tmp);
568 	}
569 	intel_de_write(dev_priv, MIPI_EOT_DISABLE(port), CLOCKSTOP);
570 }
571