root/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c

DEFINITIONS

1. pl_to_div
2. div_to_pl
3. gk20a_pllg_read_mnp
4. gk20a_pllg_write_mnp
5. gk20a_pllg_calc_rate
6. gk20a_pllg_calc_mnp
7. gk20a_pllg_slide
8. gk20a_pllg_enable
9. gk20a_pllg_disable
10. gk20a_pllg_program_mnp
11. gk20a_pllg_program_mnp_slide
12. gk20a_clk_read
13. gk20a_clk_calc
14. gk20a_clk_prog
15. gk20a_clk_tidy
16. gk20a_clk_setup_slide
17. gk20a_clk_fini
18. gk20a_clk_init
19. gk20a_clk_ctor
20. gk20a_clk_new

   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 }