1 // SPDX-License-Identifier: (GPL-2.0 OR MIT) 2 /* 3 * Copyright 2018 NXP. 4 * 5 * This driver supports the SCCG plls found in the imx8m SOCs 6 * 7 * Documentation for this SCCG pll can be found at: 8 * https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf#page=834 9 */ 10 11 #include <linux/clk-provider.h> 12 #include <linux/err.h> 13 #include <linux/export.h> 14 #include <linux/io.h> 15 #include <linux/iopoll.h> 16 #include <linux/slab.h> 17 #include <linux/bitfield.h> 18 19 #include "clk.h" 20 21 /* PLL CFGs */ 22 #define PLL_CFG0 0x0 23 #define PLL_CFG1 0x4 24 #define PLL_CFG2 0x8 25 26 #define PLL_DIVF1_MASK GENMASK(18, 13) 27 #define PLL_DIVF2_MASK GENMASK(12, 7) 28 #define PLL_DIVR1_MASK GENMASK(27, 25) 29 #define PLL_DIVR2_MASK GENMASK(24, 19) 30 #define PLL_DIVQ_MASK GENMASK(6, 1) 31 #define PLL_REF_MASK GENMASK(2, 0) 32 33 #define PLL_LOCK_MASK BIT(31) 34 #define PLL_PD_MASK BIT(7) 35 36 /* These are the specification limits for the SSCG PLL */ 37 #define PLL_REF_MIN_FREQ 25000000UL 38 #define PLL_REF_MAX_FREQ 235000000UL 39 40 #define PLL_STAGE1_MIN_FREQ 1600000000UL 41 #define PLL_STAGE1_MAX_FREQ 2400000000UL 42 43 #define PLL_STAGE1_REF_MIN_FREQ 25000000UL 44 #define PLL_STAGE1_REF_MAX_FREQ 54000000UL 45 46 #define PLL_STAGE2_MIN_FREQ 1200000000UL 47 #define PLL_STAGE2_MAX_FREQ 2400000000UL 48 49 #define PLL_STAGE2_REF_MIN_FREQ 54000000UL 50 #define PLL_STAGE2_REF_MAX_FREQ 75000000UL 51 52 #define PLL_OUT_MIN_FREQ 20000000UL 53 #define PLL_OUT_MAX_FREQ 1200000000UL 54 55 #define PLL_DIVR1_MAX 7 56 #define PLL_DIVR2_MAX 63 57 #define PLL_DIVF1_MAX 63 58 #define PLL_DIVF2_MAX 63 59 #define PLL_DIVQ_MAX 63 60 61 #define PLL_BYPASS_NONE 0x0 62 #define PLL_BYPASS1 0x2 63 #define PLL_BYPASS2 0x1 64 65 #define SSCG_PLL_BYPASS1_MASK BIT(5) 66 #define SSCG_PLL_BYPASS2_MASK BIT(4) 67 #define SSCG_PLL_BYPASS_MASK GENMASK(5, 4) 68 69 #define PLL_SCCG_LOCK_TIMEOUT 70 70 71 struct clk_sscg_pll_setup { 72 int divr1, divf1; 73 int divr2, divf2; 74 int divq; 75 int bypass; 76 uint64_t vco1; 77 uint64_t vco2; 78 uint64_t fout; 79 uint64_t ref; 80 uint64_t ref_div1; 81 uint64_t ref_div2; 82 uint64_t fout_request; 83 int fout_error; 84 }; 85 86 struct clk_sscg_pll { 87 struct clk_hw hw; 88 const struct clk_ops ops; 89 void __iomem *base; 90 struct clk_sscg_pll_setup setup; 91 u8 parent; 92 u8 bypass1; 93 u8 bypass2; 94 }; 95 96 #define to_clk_sscg_pll(_hw) container_of(_hw, struct clk_sscg_pll, hw) 97 98 static int clk_sscg_pll_wait_lock(struct clk_sscg_pll *pll) 99 { 100 u32 val; 101 102 val = readl_relaxed(pll->base + PLL_CFG0); 103 104 /* don't wait for lock if all plls are bypassed */ 105 if (!(val & SSCG_PLL_BYPASS2_MASK)) 106 return readl_poll_timeout(pll->base, val, val & PLL_LOCK_MASK, 107 0, PLL_SCCG_LOCK_TIMEOUT); 108 109 return 0; 110 } 111 112 static int clk_sscg_pll2_check_match(struct clk_sscg_pll_setup *setup, 113 struct clk_sscg_pll_setup *temp_setup) 114 { 115 int new_diff = temp_setup->fout - temp_setup->fout_request; 116 int diff = temp_setup->fout_error; 117 118 if (abs(diff) > abs(new_diff)) { 119 temp_setup->fout_error = new_diff; 120 memcpy(setup, temp_setup, sizeof(struct clk_sscg_pll_setup)); 121 122 if (temp_setup->fout_request == temp_setup->fout) 123 return 0; 124 } 125 return -1; 126 } 127 128 static int clk_sscg_divq_lookup(struct clk_sscg_pll_setup *setup, 129 struct clk_sscg_pll_setup *temp_setup) 130 { 131 int ret = -EINVAL; 132 133 for (temp_setup->divq = 0; temp_setup->divq <= PLL_DIVQ_MAX; 134 temp_setup->divq++) { 135 temp_setup->vco2 = temp_setup->vco1; 136 do_div(temp_setup->vco2, temp_setup->divr2 + 1); 137 temp_setup->vco2 *= 2; 138 temp_setup->vco2 *= temp_setup->divf2 + 1; 139 if (temp_setup->vco2 >= PLL_STAGE2_MIN_FREQ && 140 temp_setup->vco2 <= PLL_STAGE2_MAX_FREQ) { 141 temp_setup->fout = temp_setup->vco2; 142 do_div(temp_setup->fout, 2 * (temp_setup->divq + 1)); 143 144 ret = clk_sscg_pll2_check_match(setup, temp_setup); 145 if (!ret) { 146 temp_setup->bypass = PLL_BYPASS1; 147 return ret; 148 } 149 } 150 } 151 152 return ret; 153 } 154 155 static int clk_sscg_divf2_lookup(struct clk_sscg_pll_setup *setup, 156 struct clk_sscg_pll_setup *temp_setup) 157 { 158 int ret = -EINVAL; 159 160 for (temp_setup->divf2 = 0; temp_setup->divf2 <= PLL_DIVF2_MAX; 161 temp_setup->divf2++) { 162 ret = clk_sscg_divq_lookup(setup, temp_setup); 163 if (!ret) 164 return ret; 165 } 166 167 return ret; 168 } 169 170 static int clk_sscg_divr2_lookup(struct clk_sscg_pll_setup *setup, 171 struct clk_sscg_pll_setup *temp_setup) 172 { 173 int ret = -EINVAL; 174 175 for (temp_setup->divr2 = 0; temp_setup->divr2 <= PLL_DIVR2_MAX; 176 temp_setup->divr2++) { 177 temp_setup->ref_div2 = temp_setup->vco1; 178 do_div(temp_setup->ref_div2, temp_setup->divr2 + 1); 179 if (temp_setup->ref_div2 >= PLL_STAGE2_REF_MIN_FREQ && 180 temp_setup->ref_div2 <= PLL_STAGE2_REF_MAX_FREQ) { 181 ret = clk_sscg_divf2_lookup(setup, temp_setup); 182 if (!ret) 183 return ret; 184 } 185 } 186 187 return ret; 188 } 189 190 static int clk_sscg_pll2_find_setup(struct clk_sscg_pll_setup *setup, 191 struct clk_sscg_pll_setup *temp_setup, 192 uint64_t ref) 193 { 194 int ret; 195 196 if (ref < PLL_STAGE1_MIN_FREQ || ref > PLL_STAGE1_MAX_FREQ) 197 return -EINVAL; 198 199 temp_setup->vco1 = ref; 200 201 ret = clk_sscg_divr2_lookup(setup, temp_setup); 202 return ret; 203 } 204 205 static int clk_sscg_divf1_lookup(struct clk_sscg_pll_setup *setup, 206 struct clk_sscg_pll_setup *temp_setup) 207 { 208 int ret = -EINVAL; 209 210 for (temp_setup->divf1 = 0; temp_setup->divf1 <= PLL_DIVF1_MAX; 211 temp_setup->divf1++) { 212 uint64_t vco1 = temp_setup->ref; 213 214 do_div(vco1, temp_setup->divr1 + 1); 215 vco1 *= 2; 216 vco1 *= temp_setup->divf1 + 1; 217 218 ret = clk_sscg_pll2_find_setup(setup, temp_setup, vco1); 219 if (!ret) { 220 temp_setup->bypass = PLL_BYPASS_NONE; 221 return ret; 222 } 223 } 224 225 return ret; 226 } 227 228 static int clk_sscg_divr1_lookup(struct clk_sscg_pll_setup *setup, 229 struct clk_sscg_pll_setup *temp_setup) 230 { 231 int ret = -EINVAL; 232 233 for (temp_setup->divr1 = 0; temp_setup->divr1 <= PLL_DIVR1_MAX; 234 temp_setup->divr1++) { 235 temp_setup->ref_div1 = temp_setup->ref; 236 do_div(temp_setup->ref_div1, temp_setup->divr1 + 1); 237 if (temp_setup->ref_div1 >= PLL_STAGE1_REF_MIN_FREQ && 238 temp_setup->ref_div1 <= PLL_STAGE1_REF_MAX_FREQ) { 239 ret = clk_sscg_divf1_lookup(setup, temp_setup); 240 if (!ret) 241 return ret; 242 } 243 } 244 245 return ret; 246 } 247 248 static int clk_sscg_pll1_find_setup(struct clk_sscg_pll_setup *setup, 249 struct clk_sscg_pll_setup *temp_setup, 250 uint64_t ref) 251 { 252 int ret; 253 254 if (ref < PLL_REF_MIN_FREQ || ref > PLL_REF_MAX_FREQ) 255 return -EINVAL; 256 257 temp_setup->ref = ref; 258 259 ret = clk_sscg_divr1_lookup(setup, temp_setup); 260 261 return ret; 262 } 263 264 static int clk_sscg_pll_find_setup(struct clk_sscg_pll_setup *setup, 265 uint64_t prate, 266 uint64_t rate, int try_bypass) 267 { 268 struct clk_sscg_pll_setup temp_setup; 269 int ret = -EINVAL; 270 271 memset(&temp_setup, 0, sizeof(struct clk_sscg_pll_setup)); 272 memset(setup, 0, sizeof(struct clk_sscg_pll_setup)); 273 274 temp_setup.fout_error = PLL_OUT_MAX_FREQ; 275 temp_setup.fout_request = rate; 276 277 switch (try_bypass) { 278 case PLL_BYPASS2: 279 if (prate == rate) { 280 setup->bypass = PLL_BYPASS2; 281 setup->fout = rate; 282 ret = 0; 283 } 284 break; 285 case PLL_BYPASS1: 286 ret = clk_sscg_pll2_find_setup(setup, &temp_setup, prate); 287 break; 288 case PLL_BYPASS_NONE: 289 ret = clk_sscg_pll1_find_setup(setup, &temp_setup, prate); 290 break; 291 } 292 293 return ret; 294 } 295 296 static int clk_sscg_pll_is_prepared(struct clk_hw *hw) 297 { 298 struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); 299 300 u32 val = readl_relaxed(pll->base + PLL_CFG0); 301 302 return (val & PLL_PD_MASK) ? 0 : 1; 303 } 304 305 static int clk_sscg_pll_prepare(struct clk_hw *hw) 306 { 307 struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); 308 u32 val; 309 310 val = readl_relaxed(pll->base + PLL_CFG0); 311 val &= ~PLL_PD_MASK; 312 writel_relaxed(val, pll->base + PLL_CFG0); 313 314 return clk_sscg_pll_wait_lock(pll); 315 } 316 317 static void clk_sscg_pll_unprepare(struct clk_hw *hw) 318 { 319 struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); 320 u32 val; 321 322 val = readl_relaxed(pll->base + PLL_CFG0); 323 val |= PLL_PD_MASK; 324 writel_relaxed(val, pll->base + PLL_CFG0); 325 } 326 327 static unsigned long clk_sscg_pll_recalc_rate(struct clk_hw *hw, 328 unsigned long parent_rate) 329 { 330 struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); 331 u32 val, divr1, divf1, divr2, divf2, divq; 332 u64 temp64; 333 334 val = readl_relaxed(pll->base + PLL_CFG2); 335 divr1 = FIELD_GET(PLL_DIVR1_MASK, val); 336 divr2 = FIELD_GET(PLL_DIVR2_MASK, val); 337 divf1 = FIELD_GET(PLL_DIVF1_MASK, val); 338 divf2 = FIELD_GET(PLL_DIVF2_MASK, val); 339 divq = FIELD_GET(PLL_DIVQ_MASK, val); 340 341 temp64 = parent_rate; 342 343 val = readl(pll->base + PLL_CFG0); 344 if (val & SSCG_PLL_BYPASS2_MASK) { 345 temp64 = parent_rate; 346 } else if (val & SSCG_PLL_BYPASS1_MASK) { 347 temp64 *= divf2; 348 do_div(temp64, (divr2 + 1) * (divq + 1)); 349 } else { 350 temp64 *= 2; 351 temp64 *= (divf1 + 1) * (divf2 + 1); 352 do_div(temp64, (divr1 + 1) * (divr2 + 1) * (divq + 1)); 353 } 354 355 return temp64; 356 } 357 358 static int clk_sscg_pll_set_rate(struct clk_hw *hw, unsigned long rate, 359 unsigned long parent_rate) 360 { 361 struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); 362 struct clk_sscg_pll_setup *setup = &pll->setup; 363 u32 val; 364 365 /* set bypass here too since the parent might be the same */ 366 val = readl(pll->base + PLL_CFG0); 367 val &= ~SSCG_PLL_BYPASS_MASK; 368 val |= FIELD_PREP(SSCG_PLL_BYPASS_MASK, setup->bypass); 369 writel(val, pll->base + PLL_CFG0); 370 371 val = readl_relaxed(pll->base + PLL_CFG2); 372 val &= ~(PLL_DIVF1_MASK | PLL_DIVF2_MASK); 373 val &= ~(PLL_DIVR1_MASK | PLL_DIVR2_MASK | PLL_DIVQ_MASK); 374 val |= FIELD_PREP(PLL_DIVF1_MASK, setup->divf1); 375 val |= FIELD_PREP(PLL_DIVF2_MASK, setup->divf2); 376 val |= FIELD_PREP(PLL_DIVR1_MASK, setup->divr1); 377 val |= FIELD_PREP(PLL_DIVR2_MASK, setup->divr2); 378 val |= FIELD_PREP(PLL_DIVQ_MASK, setup->divq); 379 writel_relaxed(val, pll->base + PLL_CFG2); 380 381 return clk_sscg_pll_wait_lock(pll); 382 } 383 384 static u8 clk_sscg_pll_get_parent(struct clk_hw *hw) 385 { 386 struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); 387 u32 val; 388 u8 ret = pll->parent; 389 390 val = readl(pll->base + PLL_CFG0); 391 if (val & SSCG_PLL_BYPASS2_MASK) 392 ret = pll->bypass2; 393 else if (val & SSCG_PLL_BYPASS1_MASK) 394 ret = pll->bypass1; 395 return ret; 396 } 397 398 static int clk_sscg_pll_set_parent(struct clk_hw *hw, u8 index) 399 { 400 struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); 401 u32 val; 402 403 val = readl(pll->base + PLL_CFG0); 404 val &= ~SSCG_PLL_BYPASS_MASK; 405 val |= FIELD_PREP(SSCG_PLL_BYPASS_MASK, pll->setup.bypass); 406 writel(val, pll->base + PLL_CFG0); 407 408 return clk_sscg_pll_wait_lock(pll); 409 } 410 411 static int __clk_sscg_pll_determine_rate(struct clk_hw *hw, 412 struct clk_rate_request *req, 413 uint64_t min, 414 uint64_t max, 415 uint64_t rate, 416 int bypass) 417 { 418 struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); 419 struct clk_sscg_pll_setup *setup = &pll->setup; 420 struct clk_hw *parent_hw = NULL; 421 int bypass_parent_index; 422 int ret; 423 424 req->max_rate = max; 425 req->min_rate = min; 426 427 switch (bypass) { 428 case PLL_BYPASS2: 429 bypass_parent_index = pll->bypass2; 430 break; 431 case PLL_BYPASS1: 432 bypass_parent_index = pll->bypass1; 433 break; 434 default: 435 bypass_parent_index = pll->parent; 436 break; 437 } 438 439 parent_hw = clk_hw_get_parent_by_index(hw, bypass_parent_index); 440 ret = __clk_determine_rate(parent_hw, req); 441 if (!ret) { 442 ret = clk_sscg_pll_find_setup(setup, req->rate, 443 rate, bypass); 444 } 445 446 req->best_parent_hw = parent_hw; 447 req->best_parent_rate = req->rate; 448 req->rate = setup->fout; 449 450 return ret; 451 } 452 453 static int clk_sscg_pll_determine_rate(struct clk_hw *hw, 454 struct clk_rate_request *req) 455 { 456 struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); 457 struct clk_sscg_pll_setup *setup = &pll->setup; 458 uint64_t rate = req->rate; 459 uint64_t min = req->min_rate; 460 uint64_t max = req->max_rate; 461 int ret; 462 463 if (rate < PLL_OUT_MIN_FREQ || rate > PLL_OUT_MAX_FREQ) 464 return -EINVAL; 465 466 ret = __clk_sscg_pll_determine_rate(hw, req, req->rate, req->rate, 467 rate, PLL_BYPASS2); 468 if (!ret) 469 return ret; 470 471 ret = __clk_sscg_pll_determine_rate(hw, req, PLL_STAGE1_REF_MIN_FREQ, 472 PLL_STAGE1_REF_MAX_FREQ, rate, 473 PLL_BYPASS1); 474 if (!ret) 475 return ret; 476 477 ret = __clk_sscg_pll_determine_rate(hw, req, PLL_REF_MIN_FREQ, 478 PLL_REF_MAX_FREQ, rate, 479 PLL_BYPASS_NONE); 480 if (!ret) 481 return ret; 482 483 if (setup->fout >= min && setup->fout <= max) 484 ret = 0; 485 486 return ret; 487 } 488 489 static const struct clk_ops clk_sscg_pll_ops = { 490 .prepare = clk_sscg_pll_prepare, 491 .unprepare = clk_sscg_pll_unprepare, 492 .is_prepared = clk_sscg_pll_is_prepared, 493 .recalc_rate = clk_sscg_pll_recalc_rate, 494 .set_rate = clk_sscg_pll_set_rate, 495 .set_parent = clk_sscg_pll_set_parent, 496 .get_parent = clk_sscg_pll_get_parent, 497 .determine_rate = clk_sscg_pll_determine_rate, 498 }; 499 500 struct clk_hw *imx_clk_hw_sscg_pll(const char *name, 501 const char * const *parent_names, 502 u8 num_parents, 503 u8 parent, u8 bypass1, u8 bypass2, 504 void __iomem *base, 505 unsigned long flags) 506 { 507 struct clk_sscg_pll *pll; 508 struct clk_init_data init; 509 struct clk_hw *hw; 510 int ret; 511 512 pll = kzalloc(sizeof(*pll), GFP_KERNEL); 513 if (!pll) 514 return ERR_PTR(-ENOMEM); 515 516 pll->parent = parent; 517 pll->bypass1 = bypass1; 518 pll->bypass2 = bypass2; 519 520 pll->base = base; 521 init.name = name; 522 init.ops = &clk_sscg_pll_ops; 523 524 init.flags = flags; 525 init.parent_names = parent_names; 526 init.num_parents = num_parents; 527 528 pll->base = base; 529 pll->hw.init = &init; 530 531 hw = &pll->hw; 532 533 ret = clk_hw_register(NULL, hw); 534 if (ret) { 535 kfree(pll); 536 return ERR_PTR(ret); 537 } 538 539 return hw; 540 } 541 EXPORT_SYMBOL_GPL(imx_clk_hw_sscg_pll); 542