1 /* 2 * Copyright (C) 2016 Atmel Corporation, 3 * Songjun Wu <songjun.wu@atmel.com>, 4 * Nicolas Ferre <nicolas.ferre@atmel.com> 5 * Copyright (C) 2017 Free Electrons, 6 * Quentin Schulz <quentin.schulz@free-electrons.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * The Sama5d2 SoC has two audio PLLs (PMC and PAD) that shares the same parent 14 * (FRAC). FRAC can output between 620 and 700MHz and only multiply the rate of 15 * its own parent. PMC and PAD can then divide the FRAC rate to best match the 16 * asked rate. 17 * 18 * Traits of FRAC clock: 19 * enable - clk_enable writes nd, fracr parameters and enables PLL 20 * rate - rate is adjustable. 21 * clk->rate = parent->rate * ((nd + 1) + (fracr / 2^22)) 22 * parent - fixed parent. No clk_set_parent support 23 * 24 * Traits of PMC clock: 25 * enable - clk_enable writes qdpmc, and enables PMC output 26 * rate - rate is adjustable. 27 * clk->rate = parent->rate / (qdpmc + 1) 28 * parent - fixed parent. No clk_set_parent support 29 * 30 * Traits of PAD clock: 31 * enable - clk_enable writes divisors and enables PAD output 32 * rate - rate is adjustable. 33 * clk->rate = parent->rate / (qdaudio * div)) 34 * parent - fixed parent. No clk_set_parent support 35 * 36 */ 37 38 #include <linux/clk.h> 39 #include <linux/clk-provider.h> 40 #include <linux/clk/at91_pmc.h> 41 #include <linux/of.h> 42 #include <linux/mfd/syscon.h> 43 #include <linux/regmap.h> 44 #include <linux/slab.h> 45 46 #include "pmc.h" 47 48 #define AUDIO_PLL_DIV_FRAC BIT(22) 49 #define AUDIO_PLL_ND_MAX (AT91_PMC_AUDIO_PLL_ND_MASK >> \ 50 AT91_PMC_AUDIO_PLL_ND_OFFSET) 51 52 #define AUDIO_PLL_QDPAD(qd, div) ((AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV(qd) & \ 53 AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV_MASK) | \ 54 (AT91_PMC_AUDIO_PLL_QDPAD_DIV(div) & \ 55 AT91_PMC_AUDIO_PLL_QDPAD_DIV_MASK)) 56 57 #define AUDIO_PLL_QDPMC_MAX (AT91_PMC_AUDIO_PLL_QDPMC_MASK >> \ 58 AT91_PMC_AUDIO_PLL_QDPMC_OFFSET) 59 60 #define AUDIO_PLL_FOUT_MIN 620000000UL 61 #define AUDIO_PLL_FOUT_MAX 700000000UL 62 63 struct clk_audio_frac { 64 struct clk_hw hw; 65 struct regmap *regmap; 66 u32 fracr; 67 u8 nd; 68 }; 69 70 struct clk_audio_pad { 71 struct clk_hw hw; 72 struct regmap *regmap; 73 u8 qdaudio; 74 u8 div; 75 }; 76 77 struct clk_audio_pmc { 78 struct clk_hw hw; 79 struct regmap *regmap; 80 u8 qdpmc; 81 }; 82 83 #define to_clk_audio_frac(hw) container_of(hw, struct clk_audio_frac, hw) 84 #define to_clk_audio_pad(hw) container_of(hw, struct clk_audio_pad, hw) 85 #define to_clk_audio_pmc(hw) container_of(hw, struct clk_audio_pmc, hw) 86 87 static int clk_audio_pll_frac_enable(struct clk_hw *hw) 88 { 89 struct clk_audio_frac *frac = to_clk_audio_frac(hw); 90 91 regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0, 92 AT91_PMC_AUDIO_PLL_RESETN, 0); 93 regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0, 94 AT91_PMC_AUDIO_PLL_RESETN, 95 AT91_PMC_AUDIO_PLL_RESETN); 96 regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL1, 97 AT91_PMC_AUDIO_PLL_FRACR_MASK, frac->fracr); 98 99 /* 100 * reset and enable have to be done in 2 separated writes 101 * for AT91_PMC_AUDIO_PLL0 102 */ 103 regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0, 104 AT91_PMC_AUDIO_PLL_PLLEN | 105 AT91_PMC_AUDIO_PLL_ND_MASK, 106 AT91_PMC_AUDIO_PLL_PLLEN | 107 AT91_PMC_AUDIO_PLL_ND(frac->nd)); 108 109 return 0; 110 } 111 112 static int clk_audio_pll_pad_enable(struct clk_hw *hw) 113 { 114 struct clk_audio_pad *apad_ck = to_clk_audio_pad(hw); 115 116 regmap_update_bits(apad_ck->regmap, AT91_PMC_AUDIO_PLL1, 117 AT91_PMC_AUDIO_PLL_QDPAD_MASK, 118 AUDIO_PLL_QDPAD(apad_ck->qdaudio, apad_ck->div)); 119 regmap_update_bits(apad_ck->regmap, AT91_PMC_AUDIO_PLL0, 120 AT91_PMC_AUDIO_PLL_PADEN, AT91_PMC_AUDIO_PLL_PADEN); 121 122 return 0; 123 } 124 125 static int clk_audio_pll_pmc_enable(struct clk_hw *hw) 126 { 127 struct clk_audio_pmc *apmc_ck = to_clk_audio_pmc(hw); 128 129 regmap_update_bits(apmc_ck->regmap, AT91_PMC_AUDIO_PLL0, 130 AT91_PMC_AUDIO_PLL_PMCEN | 131 AT91_PMC_AUDIO_PLL_QDPMC_MASK, 132 AT91_PMC_AUDIO_PLL_PMCEN | 133 AT91_PMC_AUDIO_PLL_QDPMC(apmc_ck->qdpmc)); 134 return 0; 135 } 136 137 static void clk_audio_pll_frac_disable(struct clk_hw *hw) 138 { 139 struct clk_audio_frac *frac = to_clk_audio_frac(hw); 140 141 regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0, 142 AT91_PMC_AUDIO_PLL_PLLEN, 0); 143 /* do it in 2 separated writes */ 144 regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0, 145 AT91_PMC_AUDIO_PLL_RESETN, 0); 146 } 147 148 static void clk_audio_pll_pad_disable(struct clk_hw *hw) 149 { 150 struct clk_audio_pad *apad_ck = to_clk_audio_pad(hw); 151 152 regmap_update_bits(apad_ck->regmap, AT91_PMC_AUDIO_PLL0, 153 AT91_PMC_AUDIO_PLL_PADEN, 0); 154 } 155 156 static void clk_audio_pll_pmc_disable(struct clk_hw *hw) 157 { 158 struct clk_audio_pmc *apmc_ck = to_clk_audio_pmc(hw); 159 160 regmap_update_bits(apmc_ck->regmap, AT91_PMC_AUDIO_PLL0, 161 AT91_PMC_AUDIO_PLL_PMCEN, 0); 162 } 163 164 static unsigned long clk_audio_pll_fout(unsigned long parent_rate, 165 unsigned long nd, unsigned long fracr) 166 { 167 unsigned long long fr = (unsigned long long)parent_rate * fracr; 168 169 pr_debug("A PLL: %s, fr = %llu\n", __func__, fr); 170 171 fr = DIV_ROUND_CLOSEST_ULL(fr, AUDIO_PLL_DIV_FRAC); 172 173 pr_debug("A PLL: %s, fr = %llu\n", __func__, fr); 174 175 return parent_rate * (nd + 1) + fr; 176 } 177 178 static unsigned long clk_audio_pll_frac_recalc_rate(struct clk_hw *hw, 179 unsigned long parent_rate) 180 { 181 struct clk_audio_frac *frac = to_clk_audio_frac(hw); 182 unsigned long fout; 183 184 fout = clk_audio_pll_fout(parent_rate, frac->nd, frac->fracr); 185 186 pr_debug("A PLL: %s, fout = %lu (nd = %u, fracr = %lu)\n", __func__, 187 fout, frac->nd, (unsigned long)frac->fracr); 188 189 return fout; 190 } 191 192 static unsigned long clk_audio_pll_pad_recalc_rate(struct clk_hw *hw, 193 unsigned long parent_rate) 194 { 195 struct clk_audio_pad *apad_ck = to_clk_audio_pad(hw); 196 unsigned long apad_rate = 0; 197 198 if (apad_ck->qdaudio && apad_ck->div) 199 apad_rate = parent_rate / (apad_ck->qdaudio * apad_ck->div); 200 201 pr_debug("A PLL/PAD: %s, apad_rate = %lu (div = %u, qdaudio = %u)\n", 202 __func__, apad_rate, apad_ck->div, apad_ck->qdaudio); 203 204 return apad_rate; 205 } 206 207 static unsigned long clk_audio_pll_pmc_recalc_rate(struct clk_hw *hw, 208 unsigned long parent_rate) 209 { 210 struct clk_audio_pmc *apmc_ck = to_clk_audio_pmc(hw); 211 unsigned long apmc_rate = 0; 212 213 apmc_rate = parent_rate / (apmc_ck->qdpmc + 1); 214 215 pr_debug("A PLL/PMC: %s, apmc_rate = %lu (qdpmc = %u)\n", __func__, 216 apmc_rate, apmc_ck->qdpmc); 217 218 return apmc_rate; 219 } 220 221 static int clk_audio_pll_frac_compute_frac(unsigned long rate, 222 unsigned long parent_rate, 223 unsigned long *nd, 224 unsigned long *fracr) 225 { 226 unsigned long long tmp, rem; 227 228 if (!rate) 229 return -EINVAL; 230 231 tmp = rate; 232 rem = do_div(tmp, parent_rate); 233 if (!tmp || tmp >= AUDIO_PLL_ND_MAX) 234 return -EINVAL; 235 236 *nd = tmp - 1; 237 238 tmp = rem * AUDIO_PLL_DIV_FRAC; 239 tmp = DIV_ROUND_CLOSEST_ULL(tmp, parent_rate); 240 if (tmp > AT91_PMC_AUDIO_PLL_FRACR_MASK) 241 return -EINVAL; 242 243 /* we can cast here as we verified the bounds just above */ 244 *fracr = (unsigned long)tmp; 245 246 return 0; 247 } 248 249 static int clk_audio_pll_frac_determine_rate(struct clk_hw *hw, 250 struct clk_rate_request *req) 251 { 252 unsigned long fracr, nd; 253 int ret; 254 255 pr_debug("A PLL: %s, rate = %lu (parent_rate = %lu)\n", __func__, 256 req->rate, req->best_parent_rate); 257 258 req->rate = clamp(req->rate, AUDIO_PLL_FOUT_MIN, AUDIO_PLL_FOUT_MAX); 259 260 req->min_rate = max(req->min_rate, AUDIO_PLL_FOUT_MIN); 261 req->max_rate = min(req->max_rate, AUDIO_PLL_FOUT_MAX); 262 263 ret = clk_audio_pll_frac_compute_frac(req->rate, req->best_parent_rate, 264 &nd, &fracr); 265 if (ret) 266 return ret; 267 268 req->rate = clk_audio_pll_fout(req->best_parent_rate, nd, fracr); 269 270 req->best_parent_hw = clk_hw_get_parent(hw); 271 272 pr_debug("A PLL: %s, best_rate = %lu (nd = %lu, fracr = %lu)\n", 273 __func__, req->rate, nd, fracr); 274 275 return 0; 276 } 277 278 static long clk_audio_pll_pad_round_rate(struct clk_hw *hw, unsigned long rate, 279 unsigned long *parent_rate) 280 { 281 struct clk_hw *pclk = clk_hw_get_parent(hw); 282 long best_rate = -EINVAL; 283 unsigned long best_parent_rate; 284 unsigned long tmp_qd; 285 u32 div; 286 long tmp_rate; 287 int tmp_diff; 288 int best_diff = -1; 289 290 pr_debug("A PLL/PAD: %s, rate = %lu (parent_rate = %lu)\n", __func__, 291 rate, *parent_rate); 292 293 /* 294 * Rate divisor is actually made of two different divisors, multiplied 295 * between themselves before dividing the rate. 296 * tmp_qd goes from 1 to 31 and div is either 2 or 3. 297 * In order to avoid testing twice the rate divisor (e.g. divisor 12 can 298 * be found with (tmp_qd, div) = (2, 6) or (3, 4)), we remove any loop 299 * for a rate divisor when div is 2 and tmp_qd is a multiple of 3. 300 * We cannot inverse it (condition div is 3 and tmp_qd is even) or we 301 * would miss some rate divisor that aren't reachable with div being 2 302 * (e.g. rate divisor 90 is made with div = 3 and tmp_qd = 30, thus 303 * tmp_qd is even so we skip it because we think div 2 could make this 304 * rate divisor which isn't possible since tmp_qd has to be <= 31). 305 */ 306 for (tmp_qd = 1; tmp_qd < AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV_MAX; tmp_qd++) 307 for (div = 2; div <= 3; div++) { 308 if (div == 2 && tmp_qd % 3 == 0) 309 continue; 310 311 best_parent_rate = clk_hw_round_rate(pclk, 312 rate * tmp_qd * div); 313 tmp_rate = best_parent_rate / (div * tmp_qd); 314 tmp_diff = abs(rate - tmp_rate); 315 316 if (best_diff < 0 || best_diff > tmp_diff) { 317 *parent_rate = best_parent_rate; 318 best_rate = tmp_rate; 319 best_diff = tmp_diff; 320 } 321 } 322 323 pr_debug("A PLL/PAD: %s, best_rate = %ld, best_parent_rate = %lu\n", 324 __func__, best_rate, best_parent_rate); 325 326 return best_rate; 327 } 328 329 static long clk_audio_pll_pmc_round_rate(struct clk_hw *hw, unsigned long rate, 330 unsigned long *parent_rate) 331 { 332 struct clk_hw *pclk = clk_hw_get_parent(hw); 333 long best_rate = -EINVAL; 334 unsigned long best_parent_rate = 0; 335 u32 tmp_qd = 0, div; 336 long tmp_rate; 337 int tmp_diff; 338 int best_diff = -1; 339 340 pr_debug("A PLL/PMC: %s, rate = %lu (parent_rate = %lu)\n", __func__, 341 rate, *parent_rate); 342 343 for (div = 1; div <= AUDIO_PLL_QDPMC_MAX; div++) { 344 best_parent_rate = clk_round_rate(pclk->clk, rate * div); 345 tmp_rate = best_parent_rate / div; 346 tmp_diff = abs(rate - tmp_rate); 347 348 if (best_diff < 0 || best_diff > tmp_diff) { 349 *parent_rate = best_parent_rate; 350 best_rate = tmp_rate; 351 best_diff = tmp_diff; 352 tmp_qd = div; 353 } 354 } 355 356 pr_debug("A PLL/PMC: %s, best_rate = %ld, best_parent_rate = %lu (qd = %d)\n", 357 __func__, best_rate, *parent_rate, tmp_qd - 1); 358 359 return best_rate; 360 } 361 362 static int clk_audio_pll_frac_set_rate(struct clk_hw *hw, unsigned long rate, 363 unsigned long parent_rate) 364 { 365 struct clk_audio_frac *frac = to_clk_audio_frac(hw); 366 unsigned long fracr, nd; 367 int ret; 368 369 pr_debug("A PLL: %s, rate = %lu (parent_rate = %lu)\n", __func__, rate, 370 parent_rate); 371 372 if (rate < AUDIO_PLL_FOUT_MIN || rate > AUDIO_PLL_FOUT_MAX) 373 return -EINVAL; 374 375 ret = clk_audio_pll_frac_compute_frac(rate, parent_rate, &nd, &fracr); 376 if (ret) 377 return ret; 378 379 frac->nd = nd; 380 frac->fracr = fracr; 381 382 return 0; 383 } 384 385 static int clk_audio_pll_pad_set_rate(struct clk_hw *hw, unsigned long rate, 386 unsigned long parent_rate) 387 { 388 struct clk_audio_pad *apad_ck = to_clk_audio_pad(hw); 389 u8 tmp_div; 390 391 pr_debug("A PLL/PAD: %s, rate = %lu (parent_rate = %lu)\n", __func__, 392 rate, parent_rate); 393 394 if (!rate) 395 return -EINVAL; 396 397 tmp_div = parent_rate / rate; 398 if (tmp_div % 3 == 0) { 399 apad_ck->qdaudio = tmp_div / 3; 400 apad_ck->div = 3; 401 } else { 402 apad_ck->qdaudio = tmp_div / 2; 403 apad_ck->div = 2; 404 } 405 406 return 0; 407 } 408 409 static int clk_audio_pll_pmc_set_rate(struct clk_hw *hw, unsigned long rate, 410 unsigned long parent_rate) 411 { 412 struct clk_audio_pmc *apmc_ck = to_clk_audio_pmc(hw); 413 414 if (!rate) 415 return -EINVAL; 416 417 pr_debug("A PLL/PMC: %s, rate = %lu (parent_rate = %lu)\n", __func__, 418 rate, parent_rate); 419 420 apmc_ck->qdpmc = parent_rate / rate - 1; 421 422 return 0; 423 } 424 425 static const struct clk_ops audio_pll_frac_ops = { 426 .enable = clk_audio_pll_frac_enable, 427 .disable = clk_audio_pll_frac_disable, 428 .recalc_rate = clk_audio_pll_frac_recalc_rate, 429 .determine_rate = clk_audio_pll_frac_determine_rate, 430 .set_rate = clk_audio_pll_frac_set_rate, 431 }; 432 433 static const struct clk_ops audio_pll_pad_ops = { 434 .enable = clk_audio_pll_pad_enable, 435 .disable = clk_audio_pll_pad_disable, 436 .recalc_rate = clk_audio_pll_pad_recalc_rate, 437 .round_rate = clk_audio_pll_pad_round_rate, 438 .set_rate = clk_audio_pll_pad_set_rate, 439 }; 440 441 static const struct clk_ops audio_pll_pmc_ops = { 442 .enable = clk_audio_pll_pmc_enable, 443 .disable = clk_audio_pll_pmc_disable, 444 .recalc_rate = clk_audio_pll_pmc_recalc_rate, 445 .round_rate = clk_audio_pll_pmc_round_rate, 446 .set_rate = clk_audio_pll_pmc_set_rate, 447 }; 448 449 struct clk_hw * __init 450 at91_clk_register_audio_pll_frac(struct regmap *regmap, const char *name, 451 const char *parent_name) 452 { 453 struct clk_audio_frac *frac_ck; 454 struct clk_init_data init = {}; 455 int ret; 456 457 frac_ck = kzalloc(sizeof(*frac_ck), GFP_KERNEL); 458 if (!frac_ck) 459 return ERR_PTR(-ENOMEM); 460 461 init.name = name; 462 init.ops = &audio_pll_frac_ops; 463 init.parent_names = &parent_name; 464 init.num_parents = 1; 465 init.flags = CLK_SET_RATE_GATE; 466 467 frac_ck->hw.init = &init; 468 frac_ck->regmap = regmap; 469 470 ret = clk_hw_register(NULL, &frac_ck->hw); 471 if (ret) { 472 kfree(frac_ck); 473 return ERR_PTR(ret); 474 } 475 476 return &frac_ck->hw; 477 } 478 479 struct clk_hw * __init 480 at91_clk_register_audio_pll_pad(struct regmap *regmap, const char *name, 481 const char *parent_name) 482 { 483 struct clk_audio_pad *apad_ck; 484 struct clk_init_data init; 485 int ret; 486 487 apad_ck = kzalloc(sizeof(*apad_ck), GFP_KERNEL); 488 if (!apad_ck) 489 return ERR_PTR(-ENOMEM); 490 491 init.name = name; 492 init.ops = &audio_pll_pad_ops; 493 init.parent_names = &parent_name; 494 init.num_parents = 1; 495 init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE | 496 CLK_SET_RATE_PARENT; 497 498 apad_ck->hw.init = &init; 499 apad_ck->regmap = regmap; 500 501 ret = clk_hw_register(NULL, &apad_ck->hw); 502 if (ret) { 503 kfree(apad_ck); 504 return ERR_PTR(ret); 505 } 506 507 return &apad_ck->hw; 508 } 509 510 struct clk_hw * __init 511 at91_clk_register_audio_pll_pmc(struct regmap *regmap, const char *name, 512 const char *parent_name) 513 { 514 struct clk_audio_pmc *apmc_ck; 515 struct clk_init_data init; 516 int ret; 517 518 apmc_ck = kzalloc(sizeof(*apmc_ck), GFP_KERNEL); 519 if (!apmc_ck) 520 return ERR_PTR(-ENOMEM); 521 522 init.name = name; 523 init.ops = &audio_pll_pmc_ops; 524 init.parent_names = &parent_name; 525 init.num_parents = 1; 526 init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE | 527 CLK_SET_RATE_PARENT; 528 529 apmc_ck->hw.init = &init; 530 apmc_ck->regmap = regmap; 531 532 ret = clk_hw_register(NULL, &apmc_ck->hw); 533 if (ret) { 534 kfree(apmc_ck); 535 return ERR_PTR(ret); 536 } 537 538 return &apmc_ck->hw; 539 } 540