xref: /linux/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * Copyright (c) 2014-2016, NVIDIA CORPORATION. All rights reserved.
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 shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
19  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
20  * DEALINGS IN THE SOFTWARE.
21  *
22  * Shamelessly ripped off from ChromeOS's gk20a/clk_pllg.c
23  *
24  */
25 #include "priv.h"
26 #include "gk20a.h"
27 
28 #include <core/tegra.h>
29 #include <subdev/timer.h>
30 
31 static const u8 _pl_to_div[] = {
32 /* PL:   0, 1, 2, 3, 4, 5, 6,  7,  8,  9, 10, 11, 12, 13, 14 */
33 /* p: */ 1, 2, 3, 4, 5, 6, 8, 10, 12, 16, 12, 16, 20, 24, 32,
34 };
35 
36 static u32 pl_to_div(u32 pl)
37 {
38 	if (pl >= ARRAY_SIZE(_pl_to_div))
39 		return 1;
40 
41 	return _pl_to_div[pl];
42 }
43 
44 static u32 div_to_pl(u32 div)
45 {
46 	u32 pl;
47 
48 	for (pl = 0; pl < ARRAY_SIZE(_pl_to_div) - 1; pl++) {
49 		if (_pl_to_div[pl] >= div)
50 			return pl;
51 	}
52 
53 	return ARRAY_SIZE(_pl_to_div) - 1;
54 }
55 
56 static const struct gk20a_clk_pllg_params gk20a_pllg_params = {
57 	.min_vco = 1000000, .max_vco = 2064000,
58 	.min_u = 12000, .max_u = 38000,
59 	.min_m = 1, .max_m = 255,
60 	.min_n = 8, .max_n = 255,
61 	.min_pl = 1, .max_pl = 32,
62 };
63 
64 void
65 gk20a_pllg_read_mnp(struct gk20a_clk *clk, struct gk20a_pll *pll)
66 {
67 	struct nvkm_device *device = clk->base.subdev.device;
68 	u32 val;
69 
70 	val = nvkm_rd32(device, GPCPLL_COEFF);
71 	pll->m = (val >> GPCPLL_COEFF_M_SHIFT) & MASK(GPCPLL_COEFF_M_WIDTH);
72 	pll->n = (val >> GPCPLL_COEFF_N_SHIFT) & MASK(GPCPLL_COEFF_N_WIDTH);
73 	pll->pl = (val >> GPCPLL_COEFF_P_SHIFT) & MASK(GPCPLL_COEFF_P_WIDTH);
74 }
75 
76 void
77 gk20a_pllg_write_mnp(struct gk20a_clk *clk, const struct gk20a_pll *pll)
78 {
79 	struct nvkm_device *device = clk->base.subdev.device;
80 	u32 val;
81 
82 	val = (pll->m & MASK(GPCPLL_COEFF_M_WIDTH)) << GPCPLL_COEFF_M_SHIFT;
83 	val |= (pll->n & MASK(GPCPLL_COEFF_N_WIDTH)) << GPCPLL_COEFF_N_SHIFT;
84 	val |= (pll->pl & MASK(GPCPLL_COEFF_P_WIDTH)) << GPCPLL_COEFF_P_SHIFT;
85 	nvkm_wr32(device, GPCPLL_COEFF, val);
86 }
87 
88 u32
89 gk20a_pllg_calc_rate(struct gk20a_clk *clk, struct gk20a_pll *pll)
90 {
91 	u32 rate;
92 	u32 divider;
93 
94 	rate = clk->parent_rate * pll->n;
95 	divider = pll->m * clk->pl_to_div(pll->pl);
96 
97 	return rate / divider / 2;
98 }
99 
100 int
101 gk20a_pllg_calc_mnp(struct gk20a_clk *clk, unsigned long rate,
102 		    struct gk20a_pll *pll)
103 {
104 	struct nvkm_subdev *subdev = &clk->base.subdev;
105 	u32 target_clk_f, ref_clk_f, target_freq;
106 	u32 min_vco_f, max_vco_f;
107 	u32 low_pl, high_pl, best_pl;
108 	u32 target_vco_f;
109 	u32 best_m, best_n;
110 	u32 best_delta = ~0;
111 	u32 pl;
112 
113 	target_clk_f = rate * 2 / KHZ;
114 	ref_clk_f = clk->parent_rate / KHZ;
115 
116 	target_vco_f = target_clk_f + target_clk_f / 50;
117 	max_vco_f = max(clk->params->max_vco, target_vco_f);
118 	min_vco_f = clk->params->min_vco;
119 	best_m = clk->params->max_m;
120 	best_n = clk->params->min_n;
121 	best_pl = clk->params->min_pl;
122 
123 	/* min_pl <= high_pl <= max_pl */
124 	high_pl = (max_vco_f + target_vco_f - 1) / target_vco_f;
125 	high_pl = min(high_pl, clk->params->max_pl);
126 	high_pl = max(high_pl, clk->params->min_pl);
127 	high_pl = clk->div_to_pl(high_pl);
128 
129 	/* min_pl <= low_pl <= max_pl */
130 	low_pl = min_vco_f / target_vco_f;
131 	low_pl = min(low_pl, clk->params->max_pl);
132 	low_pl = max(low_pl, clk->params->min_pl);
133 	low_pl = clk->div_to_pl(low_pl);
134 
135 	nvkm_debug(subdev, "low_PL %d(div%d), high_PL %d(div%d)", low_pl,
136 		   clk->pl_to_div(low_pl), high_pl, clk->pl_to_div(high_pl));
137 
138 	/* Select lowest possible VCO */
139 	for (pl = low_pl; pl <= high_pl; pl++) {
140 		u32 m, n, n2;
141 
142 		target_vco_f = target_clk_f * clk->pl_to_div(pl);
143 
144 		for (m = clk->params->min_m; m <= clk->params->max_m; m++) {
145 			u32 u_f = ref_clk_f / m;
146 
147 			if (u_f < clk->params->min_u)
148 				break;
149 			if (u_f > clk->params->max_u)
150 				continue;
151 
152 			n = (target_vco_f * m) / ref_clk_f;
153 			n2 = ((target_vco_f * m) + (ref_clk_f - 1)) / ref_clk_f;
154 
155 			if (n > clk->params->max_n)
156 				break;
157 
158 			for (; n <= n2; n++) {
159 				u32 vco_f;
160 
161 				if (n < clk->params->min_n)
162 					continue;
163 				if (n > clk->params->max_n)
164 					break;
165 
166 				vco_f = ref_clk_f * n / m;
167 
168 				if (vco_f >= min_vco_f && vco_f <= max_vco_f) {
169 					u32 delta, lwv;
170 
171 					lwv = (vco_f + (clk->pl_to_div(pl) / 2))
172 						/ clk->pl_to_div(pl);
173 					delta = abs(lwv - target_clk_f);
174 
175 					if (delta < best_delta) {
176 						best_delta = delta;
177 						best_m = m;
178 						best_n = n;
179 						best_pl = pl;
180 
181 						if (best_delta == 0)
182 							goto found_match;
183 					}
184 				}
185 			}
186 		}
187 	}
188 
189 found_match:
190 	WARN_ON(best_delta == ~0);
191 
192 	if (best_delta != 0)
193 		nvkm_debug(subdev,
194 			   "no best match for target @ %dMHz on gpc_pll",
195 			   target_clk_f / KHZ);
196 
197 	pll->m = best_m;
198 	pll->n = best_n;
199 	pll->pl = best_pl;
200 
201 	target_freq = gk20a_pllg_calc_rate(clk, pll);
202 
203 	nvkm_debug(subdev,
204 		   "actual target freq %d KHz, M %d, N %d, PL %d(div%d)\n",
205 		   target_freq / KHZ, pll->m, pll->n, pll->pl,
206 		   clk->pl_to_div(pll->pl));
207 	return 0;
208 }
209 
210 static int
211 gk20a_pllg_slide(struct gk20a_clk *clk, u32 n)
212 {
213 	struct nvkm_subdev *subdev = &clk->base.subdev;
214 	struct nvkm_device *device = subdev->device;
215 	struct gk20a_pll pll;
216 	int ret = 0;
217 
218 	/* get old coefficients */
219 	gk20a_pllg_read_mnp(clk, &pll);
220 	/* do nothing if NDIV is the same */
221 	if (n == pll.n)
222 		return 0;
223 
224 	/* pll slowdown mode */
225 	nvkm_mask(device, GPCPLL_NDIV_SLOWDOWN,
226 		BIT(GPCPLL_NDIV_SLOWDOWN_SLOWDOWN_USING_PLL_SHIFT),
227 		BIT(GPCPLL_NDIV_SLOWDOWN_SLOWDOWN_USING_PLL_SHIFT));
228 
229 	/* new ndiv ready for ramp */
230 	pll.n = n;
231 	udelay(1);
232 	gk20a_pllg_write_mnp(clk, &pll);
233 
234 	/* dynamic ramp to new ndiv */
235 	udelay(1);
236 	nvkm_mask(device, GPCPLL_NDIV_SLOWDOWN,
237 		  BIT(GPCPLL_NDIV_SLOWDOWN_EN_DYNRAMP_SHIFT),
238 		  BIT(GPCPLL_NDIV_SLOWDOWN_EN_DYNRAMP_SHIFT));
239 
240 	/* wait for ramping to complete */
241 	if (nvkm_wait_usec(device, 500, GPC_BCAST_NDIV_SLOWDOWN_DEBUG,
242 		GPC_BCAST_NDIV_SLOWDOWN_DEBUG_PLL_DYNRAMP_DONE_SYNCED_MASK,
243 		GPC_BCAST_NDIV_SLOWDOWN_DEBUG_PLL_DYNRAMP_DONE_SYNCED_MASK) < 0)
244 		ret = -ETIMEDOUT;
245 
246 	/* exit slowdown mode */
247 	nvkm_mask(device, GPCPLL_NDIV_SLOWDOWN,
248 		BIT(GPCPLL_NDIV_SLOWDOWN_SLOWDOWN_USING_PLL_SHIFT) |
249 		BIT(GPCPLL_NDIV_SLOWDOWN_EN_DYNRAMP_SHIFT), 0);
250 	nvkm_rd32(device, GPCPLL_NDIV_SLOWDOWN);
251 
252 	return ret;
253 }
254 
255 static int
256 gk20a_pllg_enable(struct gk20a_clk *clk)
257 {
258 	struct nvkm_device *device = clk->base.subdev.device;
259 	u32 val;
260 
261 	nvkm_mask(device, GPCPLL_CFG, GPCPLL_CFG_ENABLE, GPCPLL_CFG_ENABLE);
262 	nvkm_rd32(device, GPCPLL_CFG);
263 
264 	/* enable lock detection */
265 	val = nvkm_rd32(device, GPCPLL_CFG);
266 	if (val & GPCPLL_CFG_LOCK_DET_OFF) {
267 		val &= ~GPCPLL_CFG_LOCK_DET_OFF;
268 		nvkm_wr32(device, GPCPLL_CFG, val);
269 	}
270 
271 	/* wait for lock */
272 	if (nvkm_wait_usec(device, 300, GPCPLL_CFG, GPCPLL_CFG_LOCK,
273 			   GPCPLL_CFG_LOCK) < 0)
274 		return -ETIMEDOUT;
275 
276 	/* switch to VCO mode */
277 	nvkm_mask(device, SEL_VCO, BIT(SEL_VCO_GPC2CLK_OUT_SHIFT),
278 		BIT(SEL_VCO_GPC2CLK_OUT_SHIFT));
279 
280 	return 0;
281 }
282 
283 static void
284 gk20a_pllg_disable(struct gk20a_clk *clk)
285 {
286 	struct nvkm_device *device = clk->base.subdev.device;
287 
288 	/* put PLL in bypass before disabling it */
289 	nvkm_mask(device, SEL_VCO, BIT(SEL_VCO_GPC2CLK_OUT_SHIFT), 0);
290 
291 	nvkm_mask(device, GPCPLL_CFG, GPCPLL_CFG_ENABLE, 0);
292 	nvkm_rd32(device, GPCPLL_CFG);
293 }
294 
295 static int
296 gk20a_pllg_program_mnp(struct gk20a_clk *clk, const struct gk20a_pll *pll)
297 {
298 	struct nvkm_subdev *subdev = &clk->base.subdev;
299 	struct nvkm_device *device = subdev->device;
300 	struct gk20a_pll cur_pll;
301 	int ret;
302 
303 	gk20a_pllg_read_mnp(clk, &cur_pll);
304 
305 	/* split VCO-to-bypass jump in half by setting out divider 1:2 */
306 	nvkm_mask(device, GPC2CLK_OUT, GPC2CLK_OUT_VCODIV_MASK,
307 		  GPC2CLK_OUT_VCODIV2 << GPC2CLK_OUT_VCODIV_SHIFT);
308 	/* Intentional 2nd write to assure linear divider operation */
309 	nvkm_mask(device, GPC2CLK_OUT, GPC2CLK_OUT_VCODIV_MASK,
310 		  GPC2CLK_OUT_VCODIV2 << GPC2CLK_OUT_VCODIV_SHIFT);
311 	nvkm_rd32(device, GPC2CLK_OUT);
312 	udelay(2);
313 
314 	gk20a_pllg_disable(clk);
315 
316 	gk20a_pllg_write_mnp(clk, pll);
317 
318 	ret = gk20a_pllg_enable(clk);
319 	if (ret)
320 		return ret;
321 
322 	/* restore out divider 1:1 */
323 	udelay(2);
324 	nvkm_mask(device, GPC2CLK_OUT, GPC2CLK_OUT_VCODIV_MASK,
325 		  GPC2CLK_OUT_VCODIV1 << GPC2CLK_OUT_VCODIV_SHIFT);
326 	/* Intentional 2nd write to assure linear divider operation */
327 	nvkm_mask(device, GPC2CLK_OUT, GPC2CLK_OUT_VCODIV_MASK,
328 		  GPC2CLK_OUT_VCODIV1 << GPC2CLK_OUT_VCODIV_SHIFT);
329 	nvkm_rd32(device, GPC2CLK_OUT);
330 
331 	return 0;
332 }
333 
334 static int
335 gk20a_pllg_program_mnp_slide(struct gk20a_clk *clk, const struct gk20a_pll *pll)
336 {
337 	struct gk20a_pll cur_pll;
338 	int ret;
339 
340 	if (gk20a_pllg_is_enabled(clk)) {
341 		gk20a_pllg_read_mnp(clk, &cur_pll);
342 
343 		/* just do NDIV slide if there is no change to M and PL */
344 		if (pll->m == cur_pll.m && pll->pl == cur_pll.pl)
345 			return gk20a_pllg_slide(clk, pll->n);
346 
347 		/* slide down to current NDIV_LO */
348 		cur_pll.n = gk20a_pllg_n_lo(clk, &cur_pll);
349 		ret = gk20a_pllg_slide(clk, cur_pll.n);
350 		if (ret)
351 			return ret;
352 	}
353 
354 	/* program MNP with the new clock parameters and new NDIV_LO */
355 	cur_pll = *pll;
356 	cur_pll.n = gk20a_pllg_n_lo(clk, &cur_pll);
357 	ret = gk20a_pllg_program_mnp(clk, &cur_pll);
358 	if (ret)
359 		return ret;
360 
361 	/* slide up to new NDIV */
362 	return gk20a_pllg_slide(clk, pll->n);
363 }
364 
365 static struct nvkm_pstate
366 gk20a_pstates[] = {
367 	{
368 		.base = {
369 			.domain[nv_clk_src_gpc] = 72000,
370 			.voltage = 0,
371 		},
372 	},
373 	{
374 		.base = {
375 			.domain[nv_clk_src_gpc] = 108000,
376 			.voltage = 1,
377 		},
378 	},
379 	{
380 		.base = {
381 			.domain[nv_clk_src_gpc] = 180000,
382 			.voltage = 2,
383 		},
384 	},
385 	{
386 		.base = {
387 			.domain[nv_clk_src_gpc] = 252000,
388 			.voltage = 3,
389 		},
390 	},
391 	{
392 		.base = {
393 			.domain[nv_clk_src_gpc] = 324000,
394 			.voltage = 4,
395 		},
396 	},
397 	{
398 		.base = {
399 			.domain[nv_clk_src_gpc] = 396000,
400 			.voltage = 5,
401 		},
402 	},
403 	{
404 		.base = {
405 			.domain[nv_clk_src_gpc] = 468000,
406 			.voltage = 6,
407 		},
408 	},
409 	{
410 		.base = {
411 			.domain[nv_clk_src_gpc] = 540000,
412 			.voltage = 7,
413 		},
414 	},
415 	{
416 		.base = {
417 			.domain[nv_clk_src_gpc] = 612000,
418 			.voltage = 8,
419 		},
420 	},
421 	{
422 		.base = {
423 			.domain[nv_clk_src_gpc] = 648000,
424 			.voltage = 9,
425 		},
426 	},
427 	{
428 		.base = {
429 			.domain[nv_clk_src_gpc] = 684000,
430 			.voltage = 10,
431 		},
432 	},
433 	{
434 		.base = {
435 			.domain[nv_clk_src_gpc] = 708000,
436 			.voltage = 11,
437 		},
438 	},
439 	{
440 		.base = {
441 			.domain[nv_clk_src_gpc] = 756000,
442 			.voltage = 12,
443 		},
444 	},
445 	{
446 		.base = {
447 			.domain[nv_clk_src_gpc] = 804000,
448 			.voltage = 13,
449 		},
450 	},
451 	{
452 		.base = {
453 			.domain[nv_clk_src_gpc] = 852000,
454 			.voltage = 14,
455 		},
456 	},
457 };
458 
459 int
460 gk20a_clk_read(struct nvkm_clk *base, enum nv_clk_src src)
461 {
462 	struct gk20a_clk *clk = gk20a_clk(base);
463 	struct nvkm_subdev *subdev = &clk->base.subdev;
464 	struct nvkm_device *device = subdev->device;
465 	struct gk20a_pll pll;
466 
467 	switch (src) {
468 	case nv_clk_src_crystal:
469 		return device->crystal;
470 	case nv_clk_src_gpc:
471 		gk20a_pllg_read_mnp(clk, &pll);
472 		return gk20a_pllg_calc_rate(clk, &pll) / GK20A_CLK_GPC_MDIV;
473 	default:
474 		nvkm_error(subdev, "invalid clock source %d\n", src);
475 		return -EINVAL;
476 	}
477 }
478 
479 int
480 gk20a_clk_calc(struct nvkm_clk *base, struct nvkm_cstate *cstate)
481 {
482 	struct gk20a_clk *clk = gk20a_clk(base);
483 
484 	return gk20a_pllg_calc_mnp(clk, cstate->domain[nv_clk_src_gpc] *
485 					 GK20A_CLK_GPC_MDIV, &clk->pll);
486 }
487 
488 int
489 gk20a_clk_prog(struct nvkm_clk *base)
490 {
491 	struct gk20a_clk *clk = gk20a_clk(base);
492 	int ret;
493 
494 	ret = gk20a_pllg_program_mnp_slide(clk, &clk->pll);
495 	if (ret)
496 		ret = gk20a_pllg_program_mnp(clk, &clk->pll);
497 
498 	return ret;
499 }
500 
501 void
502 gk20a_clk_tidy(struct nvkm_clk *base)
503 {
504 }
505 
506 int
507 gk20a_clk_setup_slide(struct gk20a_clk *clk)
508 {
509 	struct nvkm_subdev *subdev = &clk->base.subdev;
510 	struct nvkm_device *device = subdev->device;
511 	u32 step_a, step_b;
512 
513 	switch (clk->parent_rate) {
514 	case 12000000:
515 	case 12800000:
516 	case 13000000:
517 		step_a = 0x2b;
518 		step_b = 0x0b;
519 		break;
520 	case 19200000:
521 		step_a = 0x12;
522 		step_b = 0x08;
523 		break;
524 	case 38400000:
525 		step_a = 0x04;
526 		step_b = 0x05;
527 		break;
528 	default:
529 		nvkm_error(subdev, "invalid parent clock rate %u KHz",
530 			   clk->parent_rate / KHZ);
531 		return -EINVAL;
532 	}
533 
534 	nvkm_mask(device, GPCPLL_CFG2, 0xff << GPCPLL_CFG2_PLL_STEPA_SHIFT,
535 		step_a << GPCPLL_CFG2_PLL_STEPA_SHIFT);
536 	nvkm_mask(device, GPCPLL_CFG3, 0xff << GPCPLL_CFG3_PLL_STEPB_SHIFT,
537 		step_b << GPCPLL_CFG3_PLL_STEPB_SHIFT);
538 
539 	return 0;
540 }
541 
542 void
543 gk20a_clk_fini(struct nvkm_clk *base)
544 {
545 	struct nvkm_device *device = base->subdev.device;
546 	struct gk20a_clk *clk = gk20a_clk(base);
547 
548 	/* slide to VCO min */
549 	if (gk20a_pllg_is_enabled(clk)) {
550 		struct gk20a_pll pll;
551 		u32 n_lo;
552 
553 		gk20a_pllg_read_mnp(clk, &pll);
554 		n_lo = gk20a_pllg_n_lo(clk, &pll);
555 		gk20a_pllg_slide(clk, n_lo);
556 	}
557 
558 	gk20a_pllg_disable(clk);
559 
560 	/* set IDDQ */
561 	nvkm_mask(device, GPCPLL_CFG, GPCPLL_CFG_IDDQ, 1);
562 }
563 
564 static int
565 gk20a_clk_init(struct nvkm_clk *base)
566 {
567 	struct gk20a_clk *clk = gk20a_clk(base);
568 	struct nvkm_subdev *subdev = &clk->base.subdev;
569 	struct nvkm_device *device = subdev->device;
570 	int ret;
571 
572 	/* get out from IDDQ */
573 	nvkm_mask(device, GPCPLL_CFG, GPCPLL_CFG_IDDQ, 0);
574 	nvkm_rd32(device, GPCPLL_CFG);
575 	udelay(5);
576 
577 	nvkm_mask(device, GPC2CLK_OUT, GPC2CLK_OUT_INIT_MASK,
578 		  GPC2CLK_OUT_INIT_VAL);
579 
580 	ret = gk20a_clk_setup_slide(clk);
581 	if (ret)
582 		return ret;
583 
584 	/* Start with lowest frequency */
585 	base->func->calc(base, &base->func->pstates[0].base);
586 	ret = base->func->prog(&clk->base);
587 	if (ret) {
588 		nvkm_error(subdev, "cannot initialize clock\n");
589 		return ret;
590 	}
591 
592 	return 0;
593 }
594 
595 static const struct nvkm_clk_func
596 gk20a_clk = {
597 	.init = gk20a_clk_init,
598 	.fini = gk20a_clk_fini,
599 	.read = gk20a_clk_read,
600 	.calc = gk20a_clk_calc,
601 	.prog = gk20a_clk_prog,
602 	.tidy = gk20a_clk_tidy,
603 	.pstates = gk20a_pstates,
604 	.nr_pstates = ARRAY_SIZE(gk20a_pstates),
605 	.domains = {
606 		{ nv_clk_src_crystal, 0xff },
607 		{ nv_clk_src_gpc, 0xff, 0, "core", GK20A_CLK_GPC_MDIV },
608 		{ nv_clk_src_max }
609 	}
610 };
611 
612 int
613 gk20a_clk_ctor(struct nvkm_device *device, int index,
614 		const struct nvkm_clk_func *func,
615 		const struct gk20a_clk_pllg_params *params,
616 		struct gk20a_clk *clk)
617 {
618 	struct nvkm_device_tegra *tdev = device->func->tegra(device);
619 	int ret;
620 	int i;
621 
622 	/* Finish initializing the pstates */
623 	for (i = 0; i < func->nr_pstates; i++) {
624 		INIT_LIST_HEAD(&func->pstates[i].list);
625 		func->pstates[i].pstate = i + 1;
626 	}
627 
628 	clk->params = params;
629 	clk->parent_rate = clk_get_rate(tdev->clk);
630 
631 	ret = nvkm_clk_ctor(func, device, index, true, &clk->base);
632 	if (ret)
633 		return ret;
634 
635 	nvkm_debug(&clk->base.subdev, "parent clock rate: %d Khz\n",
636 		   clk->parent_rate / KHZ);
637 
638 	return 0;
639 }
640 
641 int
642 gk20a_clk_new(struct nvkm_device *device, int index, struct nvkm_clk **pclk)
643 {
644 	struct gk20a_clk *clk;
645 	int ret;
646 
647 	clk = kzalloc(sizeof(*clk), GFP_KERNEL);
648 	if (!clk)
649 		return -ENOMEM;
650 	*pclk = &clk->base;
651 
652 	ret = gk20a_clk_ctor(device, index, &gk20a_clk, &gk20a_pllg_params,
653 			      clk);
654 
655 	clk->pl_to_div = pl_to_div;
656 	clk->div_to_pl = div_to_pl;
657 
658 	return ret;
659 }
660