Linux-libre 5.4.49-gnu
[librecmc/linux-libre.git] / drivers / gpu / drm / nouveau / nvkm / subdev / clk / gk20a.c
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 }