1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * drivers/media/i2c/ccs-pll.c 4 * 5 * Generic MIPI CCS/SMIA/SMIA++ PLL calculator 6 * 7 * Copyright (C) 2020 Intel Corporation 8 * Copyright (C) 2011--2012 Nokia Corporation 9 * Contact: Sakari Ailus <sakari.ailus@linux.intel.com> 10 */ 11 12#include <linux/device.h> 13#include <linux/gcd.h> 14#include <linux/lcm.h> 15#include <linux/module.h> 16 17#include "ccs-pll.h" 18 19/* Return an even number or one. */ 20static inline u32 clk_div_even(u32 a) 21{ 22 return max_t(u32, 1, a & ~1); 23} 24 25/* Return an even number or one. */ 26static inline u32 clk_div_even_up(u32 a) 27{ 28 if (a == 1) 29 return 1; 30 return (a + 1) & ~1; 31} 32 33static inline u32 is_one_or_even(u32 a) 34{ 35 if (a == 1) 36 return 1; 37 if (a & 1) 38 return 0; 39 40 return 1; 41} 42 43static inline u32 one_or_more(u32 a) 44{ 45 return a ?: 1; 46} 47 48static int bounds_check(struct device *dev, u32 val, 49 u32 min, u32 max, const char *prefix, 50 char *str) 51{ 52 if (val >= min && val <= max) 53 return 0; 54 55 dev_dbg(dev, "%s_%s out of bounds: %d (%d--%d)\n", prefix, 56 str, val, min, max); 57 58 return -EINVAL; 59} 60 61#define PLL_OP 1 62#define PLL_VT 2 63 64static const char *pll_string(unsigned int which) 65{ 66 switch (which) { 67 case PLL_OP: 68 return "op"; 69 case PLL_VT: 70 return "vt"; 71 } 72 73 return NULL; 74} 75 76#define PLL_FL(f) CCS_PLL_FLAG_##f 77 78static void print_pll(struct device *dev, struct ccs_pll *pll) 79{ 80 const struct { 81 struct ccs_pll_branch_fr *fr; 82 struct ccs_pll_branch_bk *bk; 83 unsigned int which; 84 } branches[] = { 85 { &pll->vt_fr, &pll->vt_bk, PLL_VT }, 86 { &pll->op_fr, &pll->op_bk, PLL_OP } 87 }, *br; 88 unsigned int i; 89 90 dev_dbg(dev, "ext_clk_freq_hz\t\t%u\n", pll->ext_clk_freq_hz); 91 92 for (i = 0, br = branches; i < ARRAY_SIZE(branches); i++, br++) { 93 const char *s = pll_string(br->which); 94 95 if (pll->flags & CCS_PLL_FLAG_DUAL_PLL || 96 br->which == PLL_VT) { 97 dev_dbg(dev, "%s_pre_pll_clk_div\t\t%u\n", s, 98 br->fr->pre_pll_clk_div); 99 dev_dbg(dev, "%s_pll_multiplier\t\t%u\n", s, 100 br->fr->pll_multiplier); 101 102 dev_dbg(dev, "%s_pll_ip_clk_freq_hz\t%u\n", s, 103 br->fr->pll_ip_clk_freq_hz); 104 dev_dbg(dev, "%s_pll_op_clk_freq_hz\t%u\n", s, 105 br->fr->pll_op_clk_freq_hz); 106 } 107 108 if (!(pll->flags & CCS_PLL_FLAG_NO_OP_CLOCKS) || 109 br->which == PLL_VT) { 110 dev_dbg(dev, "%s_sys_clk_div\t\t%u\n", s, 111 br->bk->sys_clk_div); 112 dev_dbg(dev, "%s_pix_clk_div\t\t%u\n", s, 113 br->bk->pix_clk_div); 114 115 dev_dbg(dev, "%s_sys_clk_freq_hz\t%u\n", s, 116 br->bk->sys_clk_freq_hz); 117 dev_dbg(dev, "%s_pix_clk_freq_hz\t%u\n", s, 118 br->bk->pix_clk_freq_hz); 119 } 120 } 121 122 dev_dbg(dev, "pixel rate in pixel array:\t%u\n", 123 pll->pixel_rate_pixel_array); 124 dev_dbg(dev, "pixel rate on CSI-2 bus:\t%u\n", 125 pll->pixel_rate_csi); 126 127 dev_dbg(dev, "flags%s%s%s%s%s%s%s%s%s\n", 128 pll->flags & PLL_FL(LANE_SPEED_MODEL) ? " lane-speed" : "", 129 pll->flags & PLL_FL(LINK_DECOUPLED) ? " link-decoupled" : "", 130 pll->flags & PLL_FL(EXT_IP_PLL_DIVIDER) ? 131 " ext-ip-pll-divider" : "", 132 pll->flags & PLL_FL(FLEXIBLE_OP_PIX_CLK_DIV) ? 133 " flexible-op-pix-div" : "", 134 pll->flags & PLL_FL(FIFO_DERATING) ? " fifo-derating" : "", 135 pll->flags & PLL_FL(FIFO_OVERRATING) ? " fifo-overrating" : "", 136 pll->flags & PLL_FL(DUAL_PLL) ? " dual-pll" : "", 137 pll->flags & PLL_FL(OP_SYS_DDR) ? " op-sys-ddr" : "", 138 pll->flags & PLL_FL(OP_PIX_DDR) ? " op-pix-ddr" : ""); 139} 140 141static u32 op_sys_ddr(u32 flags) 142{ 143 return flags & CCS_PLL_FLAG_OP_SYS_DDR ? 1 : 0; 144} 145 146static u32 op_pix_ddr(u32 flags) 147{ 148 return flags & CCS_PLL_FLAG_OP_PIX_DDR ? 1 : 0; 149} 150 151static int check_fr_bounds(struct device *dev, 152 const struct ccs_pll_limits *lim, 153 struct ccs_pll *pll, unsigned int which) 154{ 155 const struct ccs_pll_branch_limits_fr *lim_fr; 156 struct ccs_pll_branch_fr *pll_fr; 157 const char *s = pll_string(which); 158 int rval; 159 160 if (which == PLL_OP) { 161 lim_fr = &lim->op_fr; 162 pll_fr = &pll->op_fr; 163 } else { 164 lim_fr = &lim->vt_fr; 165 pll_fr = &pll->vt_fr; 166 } 167 168 rval = bounds_check(dev, pll_fr->pre_pll_clk_div, 169 lim_fr->min_pre_pll_clk_div, 170 lim_fr->max_pre_pll_clk_div, s, "pre_pll_clk_div"); 171 172 if (!rval) 173 rval = bounds_check(dev, pll_fr->pll_ip_clk_freq_hz, 174 lim_fr->min_pll_ip_clk_freq_hz, 175 lim_fr->max_pll_ip_clk_freq_hz, 176 s, "pll_ip_clk_freq_hz"); 177 if (!rval) 178 rval = bounds_check(dev, pll_fr->pll_multiplier, 179 lim_fr->min_pll_multiplier, 180 lim_fr->max_pll_multiplier, 181 s, "pll_multiplier"); 182 if (!rval) 183 rval = bounds_check(dev, pll_fr->pll_op_clk_freq_hz, 184 lim_fr->min_pll_op_clk_freq_hz, 185 lim_fr->max_pll_op_clk_freq_hz, 186 s, "pll_op_clk_freq_hz"); 187 188 return rval; 189} 190 191static int check_bk_bounds(struct device *dev, 192 const struct ccs_pll_limits *lim, 193 struct ccs_pll *pll, unsigned int which) 194{ 195 const struct ccs_pll_branch_limits_bk *lim_bk; 196 struct ccs_pll_branch_bk *pll_bk; 197 const char *s = pll_string(which); 198 int rval; 199 200 if (which == PLL_OP) { 201 if (pll->flags & CCS_PLL_FLAG_NO_OP_CLOCKS) 202 return 0; 203 204 lim_bk = &lim->op_bk; 205 pll_bk = &pll->op_bk; 206 } else { 207 lim_bk = &lim->vt_bk; 208 pll_bk = &pll->vt_bk; 209 } 210 211 rval = bounds_check(dev, pll_bk->sys_clk_div, 212 lim_bk->min_sys_clk_div, 213 lim_bk->max_sys_clk_div, s, "op_sys_clk_div"); 214 if (!rval) 215 rval = bounds_check(dev, pll_bk->sys_clk_freq_hz, 216 lim_bk->min_sys_clk_freq_hz, 217 lim_bk->max_sys_clk_freq_hz, 218 s, "sys_clk_freq_hz"); 219 if (!rval) 220 rval = bounds_check(dev, pll_bk->sys_clk_div, 221 lim_bk->min_sys_clk_div, 222 lim_bk->max_sys_clk_div, 223 s, "sys_clk_div"); 224 if (!rval) 225 rval = bounds_check(dev, pll_bk->pix_clk_freq_hz, 226 lim_bk->min_pix_clk_freq_hz, 227 lim_bk->max_pix_clk_freq_hz, 228 s, "pix_clk_freq_hz"); 229 230 return rval; 231} 232 233static int check_ext_bounds(struct device *dev, struct ccs_pll *pll) 234{ 235 if (!(pll->flags & CCS_PLL_FLAG_FIFO_DERATING) && 236 pll->pixel_rate_pixel_array > pll->pixel_rate_csi) { 237 dev_dbg(dev, "device does not support derating\n"); 238 return -EINVAL; 239 } 240 241 if (!(pll->flags & CCS_PLL_FLAG_FIFO_OVERRATING) && 242 pll->pixel_rate_pixel_array < pll->pixel_rate_csi) { 243 dev_dbg(dev, "device does not support overrating\n"); 244 return -EINVAL; 245 } 246 247 return 0; 248} 249 250static void 251ccs_pll_find_vt_sys_div(struct device *dev, const struct ccs_pll_limits *lim, 252 struct ccs_pll *pll, struct ccs_pll_branch_fr *pll_fr, 253 u16 min_vt_div, u16 max_vt_div, 254 u16 *min_sys_div, u16 *max_sys_div) 255{ 256 /* 257 * Find limits for sys_clk_div. Not all values are possible with all 258 * values of pix_clk_div. 259 */ 260 *min_sys_div = lim->vt_bk.min_sys_clk_div; 261 dev_dbg(dev, "min_sys_div: %u\n", *min_sys_div); 262 *min_sys_div = max_t(u16, *min_sys_div, 263 DIV_ROUND_UP(min_vt_div, 264 lim->vt_bk.max_pix_clk_div)); 265 dev_dbg(dev, "min_sys_div: max_vt_pix_clk_div: %u\n", *min_sys_div); 266 *min_sys_div = max_t(u16, *min_sys_div, 267 pll_fr->pll_op_clk_freq_hz 268 / lim->vt_bk.max_sys_clk_freq_hz); 269 dev_dbg(dev, "min_sys_div: max_pll_op_clk_freq_hz: %u\n", *min_sys_div); 270 *min_sys_div = clk_div_even_up(*min_sys_div); 271 dev_dbg(dev, "min_sys_div: one or even: %u\n", *min_sys_div); 272 273 *max_sys_div = lim->vt_bk.max_sys_clk_div; 274 dev_dbg(dev, "max_sys_div: %u\n", *max_sys_div); 275 *max_sys_div = min_t(u16, *max_sys_div, 276 DIV_ROUND_UP(max_vt_div, 277 lim->vt_bk.min_pix_clk_div)); 278 dev_dbg(dev, "max_sys_div: min_vt_pix_clk_div: %u\n", *max_sys_div); 279 *max_sys_div = min_t(u16, *max_sys_div, 280 DIV_ROUND_UP(pll_fr->pll_op_clk_freq_hz, 281 lim->vt_bk.min_pix_clk_freq_hz)); 282 dev_dbg(dev, "max_sys_div: min_vt_pix_clk_freq_hz: %u\n", *max_sys_div); 283} 284 285#define CPHY_CONST 7 286#define DPHY_CONST 16 287#define PHY_CONST_DIV 16 288 289static inline int 290__ccs_pll_calculate_vt_tree(struct device *dev, 291 const struct ccs_pll_limits *lim, 292 struct ccs_pll *pll, u32 mul, u32 div) 293{ 294 const struct ccs_pll_branch_limits_fr *lim_fr = &lim->vt_fr; 295 const struct ccs_pll_branch_limits_bk *lim_bk = &lim->vt_bk; 296 struct ccs_pll_branch_fr *pll_fr = &pll->vt_fr; 297 struct ccs_pll_branch_bk *pll_bk = &pll->vt_bk; 298 u32 more_mul; 299 u16 best_pix_div = SHRT_MAX >> 1, best_div = lim_bk->max_sys_clk_div; 300 u16 vt_div, min_sys_div, max_sys_div, sys_div; 301 302 pll_fr->pll_ip_clk_freq_hz = 303 pll->ext_clk_freq_hz / pll_fr->pre_pll_clk_div; 304 305 dev_dbg(dev, "vt_pll_ip_clk_freq_hz %u\n", pll_fr->pll_ip_clk_freq_hz); 306 307 more_mul = one_or_more(DIV_ROUND_UP(lim_fr->min_pll_op_clk_freq_hz, 308 pll_fr->pll_ip_clk_freq_hz * mul)); 309 310 dev_dbg(dev, "more_mul: %u\n", more_mul); 311 more_mul *= DIV_ROUND_UP(lim_fr->min_pll_multiplier, mul * more_mul); 312 dev_dbg(dev, "more_mul2: %u\n", more_mul); 313 314 pll_fr->pll_multiplier = mul * more_mul; 315 316 if (pll_fr->pll_multiplier * pll_fr->pll_ip_clk_freq_hz > 317 lim_fr->max_pll_op_clk_freq_hz) 318 return -EINVAL; 319 320 pll_fr->pll_op_clk_freq_hz = 321 pll_fr->pll_ip_clk_freq_hz * pll_fr->pll_multiplier; 322 323 vt_div = div * more_mul; 324 325 ccs_pll_find_vt_sys_div(dev, lim, pll, pll_fr, vt_div, vt_div, 326 &min_sys_div, &max_sys_div); 327 328 max_sys_div = (vt_div & 1) ? 1 : max_sys_div; 329 330 dev_dbg(dev, "vt min/max_sys_div: %u,%u\n", min_sys_div, max_sys_div); 331 332 for (sys_div = min_sys_div; sys_div <= max_sys_div; 333 sys_div += 2 - (sys_div & 1)) { 334 u16 pix_div; 335 336 if (vt_div % sys_div) 337 continue; 338 339 pix_div = vt_div / sys_div; 340 341 if (pix_div < lim_bk->min_pix_clk_div || 342 pix_div > lim_bk->max_pix_clk_div) { 343 dev_dbg(dev, 344 "pix_div %u too small or too big (%u--%u)\n", 345 pix_div, 346 lim_bk->min_pix_clk_div, 347 lim_bk->max_pix_clk_div); 348 continue; 349 } 350 351 dev_dbg(dev, "sys/pix/best_pix: %u,%u,%u\n", sys_div, pix_div, 352 best_pix_div); 353 354 if (pix_div * sys_div <= best_pix_div) { 355 best_pix_div = pix_div; 356 best_div = pix_div * sys_div; 357 } 358 } 359 if (best_pix_div == SHRT_MAX >> 1) 360 return -EINVAL; 361 362 pll_bk->sys_clk_div = best_div / best_pix_div; 363 pll_bk->pix_clk_div = best_pix_div; 364 365 pll_bk->sys_clk_freq_hz = 366 pll_fr->pll_op_clk_freq_hz / pll_bk->sys_clk_div; 367 pll_bk->pix_clk_freq_hz = 368 pll_bk->sys_clk_freq_hz / pll_bk->pix_clk_div; 369 370 pll->pixel_rate_pixel_array = 371 pll_bk->pix_clk_freq_hz * pll->vt_lanes; 372 373 return 0; 374} 375 376static int ccs_pll_calculate_vt_tree(struct device *dev, 377 const struct ccs_pll_limits *lim, 378 struct ccs_pll *pll) 379{ 380 const struct ccs_pll_branch_limits_fr *lim_fr = &lim->vt_fr; 381 struct ccs_pll_branch_fr *pll_fr = &pll->vt_fr; 382 u16 min_pre_pll_clk_div = lim_fr->min_pre_pll_clk_div; 383 u16 max_pre_pll_clk_div = lim_fr->max_pre_pll_clk_div; 384 u32 pre_mul, pre_div; 385 386 pre_div = gcd(pll->pixel_rate_csi, 387 pll->ext_clk_freq_hz * pll->vt_lanes); 388 pre_mul = pll->pixel_rate_csi / pre_div; 389 pre_div = pll->ext_clk_freq_hz * pll->vt_lanes / pre_div; 390 391 /* Make sure PLL input frequency is within limits */ 392 max_pre_pll_clk_div = 393 min_t(u16, max_pre_pll_clk_div, 394 DIV_ROUND_UP(pll->ext_clk_freq_hz, 395 lim_fr->min_pll_ip_clk_freq_hz)); 396 397 min_pre_pll_clk_div = max_t(u16, min_pre_pll_clk_div, 398 pll->ext_clk_freq_hz / 399 lim_fr->max_pll_ip_clk_freq_hz); 400 401 dev_dbg(dev, "vt min/max_pre_pll_clk_div: %u,%u\n", 402 min_pre_pll_clk_div, max_pre_pll_clk_div); 403 404 for (pll_fr->pre_pll_clk_div = min_pre_pll_clk_div; 405 pll_fr->pre_pll_clk_div <= max_pre_pll_clk_div; 406 pll_fr->pre_pll_clk_div += 407 (pll->flags & CCS_PLL_FLAG_EXT_IP_PLL_DIVIDER) ? 1 : 408 2 - (pll_fr->pre_pll_clk_div & 1)) { 409 u32 mul, div; 410 int rval; 411 412 div = gcd(pre_mul * pll_fr->pre_pll_clk_div, pre_div); 413 mul = pre_mul * pll_fr->pre_pll_clk_div / div; 414 div = pre_div / div; 415 416 dev_dbg(dev, "vt pre-div/mul/div: %u,%u,%u\n", 417 pll_fr->pre_pll_clk_div, mul, div); 418 419 rval = __ccs_pll_calculate_vt_tree(dev, lim, pll, 420 mul, div); 421 if (rval) 422 continue; 423 424 rval = check_fr_bounds(dev, lim, pll, PLL_VT); 425 if (rval) 426 continue; 427 428 rval = check_bk_bounds(dev, lim, pll, PLL_VT); 429 if (rval) 430 continue; 431 432 return 0; 433 } 434 435 return -EINVAL; 436} 437 438static void 439ccs_pll_calculate_vt(struct device *dev, const struct ccs_pll_limits *lim, 440 const struct ccs_pll_branch_limits_bk *op_lim_bk, 441 struct ccs_pll *pll, struct ccs_pll_branch_fr *pll_fr, 442 struct ccs_pll_branch_bk *op_pll_bk, bool cphy, 443 u32 phy_const) 444{ 445 u16 sys_div; 446 u16 best_pix_div = SHRT_MAX >> 1; 447 u16 vt_op_binning_div; 448 u16 min_vt_div, max_vt_div, vt_div; 449 u16 min_sys_div, max_sys_div; 450 451 if (pll->flags & CCS_PLL_FLAG_NO_OP_CLOCKS) 452 goto out_calc_pixel_rate; 453 454 /* 455 * Find out whether a sensor supports derating. If it does not, VT and 456 * OP domains are required to run at the same pixel rate. 457 */ 458 if (!(pll->flags & CCS_PLL_FLAG_FIFO_DERATING)) { 459 min_vt_div = 460 op_pll_bk->sys_clk_div * op_pll_bk->pix_clk_div 461 * pll->vt_lanes * phy_const / pll->op_lanes 462 / (PHY_CONST_DIV << op_pix_ddr(pll->flags)); 463 } else { 464 /* 465 * Some sensors perform analogue binning and some do this 466 * digitally. The ones doing this digitally can be roughly be 467 * found out using this formula. The ones doing this digitally 468 * should run at higher clock rate, so smaller divisor is used 469 * on video timing side. 470 */ 471 if (lim->min_line_length_pck_bin > lim->min_line_length_pck 472 / pll->binning_horizontal) 473 vt_op_binning_div = pll->binning_horizontal; 474 else 475 vt_op_binning_div = 1; 476 dev_dbg(dev, "vt_op_binning_div: %u\n", vt_op_binning_div); 477 478 /* 479 * Profile 2 supports vt_pix_clk_div E [4, 10] 480 * 481 * Horizontal binning can be used as a base for difference in 482 * divisors. One must make sure that horizontal blanking is 483 * enough to accommodate the CSI-2 sync codes. 484 * 485 * Take scaling factor and number of VT lanes into account as well. 486 * 487 * Find absolute limits for the factor of vt divider. 488 */ 489 dev_dbg(dev, "scale_m: %u\n", pll->scale_m); 490 min_vt_div = 491 DIV_ROUND_UP(pll->bits_per_pixel 492 * op_pll_bk->sys_clk_div * pll->scale_n 493 * pll->vt_lanes * phy_const, 494 (pll->flags & 495 CCS_PLL_FLAG_LANE_SPEED_MODEL ? 496 pll->csi2.lanes : 1) 497 * vt_op_binning_div * pll->scale_m 498 * PHY_CONST_DIV << op_pix_ddr(pll->flags)); 499 } 500 501 /* Find smallest and biggest allowed vt divisor. */ 502 dev_dbg(dev, "min_vt_div: %u\n", min_vt_div); 503 min_vt_div = max_t(u16, min_vt_div, 504 DIV_ROUND_UP(pll_fr->pll_op_clk_freq_hz, 505 lim->vt_bk.max_pix_clk_freq_hz)); 506 dev_dbg(dev, "min_vt_div: max_vt_pix_clk_freq_hz: %u\n", 507 min_vt_div); 508 min_vt_div = max_t(u16, min_vt_div, lim->vt_bk.min_pix_clk_div 509 * lim->vt_bk.min_sys_clk_div); 510 dev_dbg(dev, "min_vt_div: min_vt_clk_div: %u\n", min_vt_div); 511 512 max_vt_div = lim->vt_bk.max_sys_clk_div * lim->vt_bk.max_pix_clk_div; 513 dev_dbg(dev, "max_vt_div: %u\n", max_vt_div); 514 max_vt_div = min_t(u16, max_vt_div, 515 DIV_ROUND_UP(pll_fr->pll_op_clk_freq_hz, 516 lim->vt_bk.min_pix_clk_freq_hz)); 517 dev_dbg(dev, "max_vt_div: min_vt_pix_clk_freq_hz: %u\n", 518 max_vt_div); 519 520 ccs_pll_find_vt_sys_div(dev, lim, pll, pll_fr, min_vt_div, 521 max_vt_div, &min_sys_div, &max_sys_div); 522 523 /* 524 * Find pix_div such that a legal pix_div * sys_div results 525 * into a value which is not smaller than div, the desired 526 * divisor. 527 */ 528 for (vt_div = min_vt_div; vt_div <= max_vt_div; vt_div++) { 529 u16 __max_sys_div = vt_div & 1 ? 1 : max_sys_div; 530 531 for (sys_div = min_sys_div; sys_div <= __max_sys_div; 532 sys_div += 2 - (sys_div & 1)) { 533 u16 pix_div; 534 u16 rounded_div; 535 536 pix_div = DIV_ROUND_UP(vt_div, sys_div); 537 538 if (pix_div < lim->vt_bk.min_pix_clk_div 539 || pix_div > lim->vt_bk.max_pix_clk_div) { 540 dev_dbg(dev, 541 "pix_div %u too small or too big (%u--%u)\n", 542 pix_div, 543 lim->vt_bk.min_pix_clk_div, 544 lim->vt_bk.max_pix_clk_div); 545 continue; 546 } 547 548 rounded_div = roundup(vt_div, best_pix_div); 549 550 /* Check if this one is better. */ 551 if (pix_div * sys_div <= rounded_div) 552 best_pix_div = pix_div; 553 554 /* Bail out if we've already found the best value. */ 555 if (vt_div == rounded_div) 556 break; 557 } 558 if (best_pix_div < SHRT_MAX >> 1) 559 break; 560 } 561 562 pll->vt_bk.sys_clk_div = DIV_ROUND_UP(vt_div, best_pix_div); 563 pll->vt_bk.pix_clk_div = best_pix_div; 564 565 pll->vt_bk.sys_clk_freq_hz = 566 pll_fr->pll_op_clk_freq_hz / pll->vt_bk.sys_clk_div; 567 pll->vt_bk.pix_clk_freq_hz = 568 pll->vt_bk.sys_clk_freq_hz / pll->vt_bk.pix_clk_div; 569 570out_calc_pixel_rate: 571 pll->pixel_rate_pixel_array = 572 pll->vt_bk.pix_clk_freq_hz * pll->vt_lanes; 573} 574 575/* 576 * Heuristically guess the PLL tree for a given common multiplier and 577 * divisor. Begin with the operational timing and continue to video 578 * timing once operational timing has been verified. 579 * 580 * @mul is the PLL multiplier and @div is the common divisor 581 * (pre_pll_clk_div and op_sys_clk_div combined). The final PLL 582 * multiplier will be a multiple of @mul. 583 * 584 * @return Zero on success, error code on error. 585 */ 586static int 587ccs_pll_calculate_op(struct device *dev, const struct ccs_pll_limits *lim, 588 const struct ccs_pll_branch_limits_fr *op_lim_fr, 589 const struct ccs_pll_branch_limits_bk *op_lim_bk, 590 struct ccs_pll *pll, struct ccs_pll_branch_fr *op_pll_fr, 591 struct ccs_pll_branch_bk *op_pll_bk, u32 mul, 592 u32 div, u32 op_sys_clk_freq_hz_sdr, u32 l, 593 bool cphy, u32 phy_const) 594{ 595 /* 596 * Higher multipliers (and divisors) are often required than 597 * necessitated by the external clock and the output clocks. 598 * There are limits for all values in the clock tree. These 599 * are the minimum and maximum multiplier for mul. 600 */ 601 u32 more_mul_min, more_mul_max; 602 u32 more_mul_factor; 603 u32 i; 604 605 /* 606 * Get pre_pll_clk_div so that our pll_op_clk_freq_hz won't be 607 * too high. 608 */ 609 dev_dbg(dev, "op_pre_pll_clk_div %u\n", op_pll_fr->pre_pll_clk_div); 610 611 /* Don't go above max pll multiplier. */ 612 more_mul_max = op_lim_fr->max_pll_multiplier / mul; 613 dev_dbg(dev, "more_mul_max: max_op_pll_multiplier check: %u\n", 614 more_mul_max); 615 /* Don't go above max pll op frequency. */ 616 more_mul_max = 617 min_t(u32, 618 more_mul_max, 619 op_lim_fr->max_pll_op_clk_freq_hz 620 / (pll->ext_clk_freq_hz / 621 op_pll_fr->pre_pll_clk_div * mul)); 622 dev_dbg(dev, "more_mul_max: max_pll_op_clk_freq_hz check: %u\n", 623 more_mul_max); 624 /* Don't go above the division capability of op sys clock divider. */ 625 more_mul_max = min(more_mul_max, 626 op_lim_bk->max_sys_clk_div * op_pll_fr->pre_pll_clk_div 627 / div); 628 dev_dbg(dev, "more_mul_max: max_op_sys_clk_div check: %u\n", 629 more_mul_max); 630 /* Ensure we won't go above max_pll_multiplier. */ 631 more_mul_max = min(more_mul_max, op_lim_fr->max_pll_multiplier / mul); 632 dev_dbg(dev, "more_mul_max: min_pll_multiplier check: %u\n", 633 more_mul_max); 634 635 /* Ensure we won't go below min_pll_op_clk_freq_hz. */ 636 more_mul_min = DIV_ROUND_UP(op_lim_fr->min_pll_op_clk_freq_hz, 637 pll->ext_clk_freq_hz / 638 op_pll_fr->pre_pll_clk_div * mul); 639 dev_dbg(dev, "more_mul_min: min_op_pll_op_clk_freq_hz check: %u\n", 640 more_mul_min); 641 /* Ensure we won't go below min_pll_multiplier. */ 642 more_mul_min = max(more_mul_min, 643 DIV_ROUND_UP(op_lim_fr->min_pll_multiplier, mul)); 644 dev_dbg(dev, "more_mul_min: min_op_pll_multiplier check: %u\n", 645 more_mul_min); 646 647 if (more_mul_min > more_mul_max) { 648 dev_dbg(dev, 649 "unable to compute more_mul_min and more_mul_max\n"); 650 return -EINVAL; 651 } 652 653 more_mul_factor = lcm(div, op_pll_fr->pre_pll_clk_div) / div; 654 dev_dbg(dev, "more_mul_factor: %u\n", more_mul_factor); 655 more_mul_factor = lcm(more_mul_factor, op_lim_bk->min_sys_clk_div); 656 dev_dbg(dev, "more_mul_factor: min_op_sys_clk_div: %d\n", 657 more_mul_factor); 658 i = roundup(more_mul_min, more_mul_factor); 659 if (!is_one_or_even(i)) 660 i <<= 1; 661 662 dev_dbg(dev, "final more_mul: %u\n", i); 663 if (i > more_mul_max) { 664 dev_dbg(dev, "final more_mul is bad, max %u\n", more_mul_max); 665 return -EINVAL; 666 } 667 668 op_pll_fr->pll_multiplier = mul * i; 669 op_pll_bk->sys_clk_div = div * i / op_pll_fr->pre_pll_clk_div; 670 dev_dbg(dev, "op_sys_clk_div: %u\n", op_pll_bk->sys_clk_div); 671 672 op_pll_fr->pll_ip_clk_freq_hz = pll->ext_clk_freq_hz 673 / op_pll_fr->pre_pll_clk_div; 674 675 op_pll_fr->pll_op_clk_freq_hz = op_pll_fr->pll_ip_clk_freq_hz 676 * op_pll_fr->pll_multiplier; 677 678 if (pll->flags & CCS_PLL_FLAG_LANE_SPEED_MODEL) 679 op_pll_bk->pix_clk_div = 680 (pll->bits_per_pixel 681 * pll->op_lanes * (phy_const << op_sys_ddr(pll->flags)) 682 / PHY_CONST_DIV / pll->csi2.lanes / l) 683 >> op_pix_ddr(pll->flags); 684 else 685 op_pll_bk->pix_clk_div = 686 (pll->bits_per_pixel 687 * (phy_const << op_sys_ddr(pll->flags)) 688 / PHY_CONST_DIV / l) >> op_pix_ddr(pll->flags); 689 690 op_pll_bk->pix_clk_freq_hz = 691 (op_sys_clk_freq_hz_sdr >> op_pix_ddr(pll->flags)) 692 / op_pll_bk->pix_clk_div; 693 op_pll_bk->sys_clk_freq_hz = 694 op_sys_clk_freq_hz_sdr >> op_sys_ddr(pll->flags); 695 696 dev_dbg(dev, "op_pix_clk_div: %u\n", op_pll_bk->pix_clk_div); 697 698 return 0; 699} 700 701int ccs_pll_calculate(struct device *dev, const struct ccs_pll_limits *lim, 702 struct ccs_pll *pll) 703{ 704 const struct ccs_pll_branch_limits_fr *op_lim_fr; 705 const struct ccs_pll_branch_limits_bk *op_lim_bk; 706 struct ccs_pll_branch_fr *op_pll_fr; 707 struct ccs_pll_branch_bk *op_pll_bk; 708 bool cphy = pll->bus_type == CCS_PLL_BUS_TYPE_CSI2_CPHY; 709 u32 phy_const = cphy ? CPHY_CONST : DPHY_CONST; 710 u32 op_sys_clk_freq_hz_sdr; 711 u16 min_op_pre_pll_clk_div; 712 u16 max_op_pre_pll_clk_div; 713 u32 mul, div; 714 u32 l = (!pll->op_bits_per_lane || 715 pll->op_bits_per_lane >= pll->bits_per_pixel) ? 1 : 2; 716 u32 i; 717 int rval = -EINVAL; 718 719 if (!(pll->flags & CCS_PLL_FLAG_LANE_SPEED_MODEL)) { 720 pll->op_lanes = 1; 721 pll->vt_lanes = 1; 722 } 723 724 if (pll->flags & CCS_PLL_FLAG_DUAL_PLL) { 725 op_lim_fr = &lim->op_fr; 726 op_lim_bk = &lim->op_bk; 727 op_pll_fr = &pll->op_fr; 728 op_pll_bk = &pll->op_bk; 729 } else if (pll->flags & CCS_PLL_FLAG_NO_OP_CLOCKS) { 730 /* 731 * If there's no OP PLL at all, use the VT values 732 * instead. The OP values are ignored for the rest of 733 * the PLL calculation. 734 */ 735 op_lim_fr = &lim->vt_fr; 736 op_lim_bk = &lim->vt_bk; 737 op_pll_fr = &pll->vt_fr; 738 op_pll_bk = &pll->vt_bk; 739 } else { 740 op_lim_fr = &lim->vt_fr; 741 op_lim_bk = &lim->op_bk; 742 op_pll_fr = &pll->vt_fr; 743 op_pll_bk = &pll->op_bk; 744 } 745 746 if (!pll->op_lanes || !pll->vt_lanes || !pll->bits_per_pixel || 747 !pll->ext_clk_freq_hz || !pll->link_freq || !pll->scale_m || 748 !op_lim_fr->min_pll_ip_clk_freq_hz || 749 !op_lim_fr->max_pll_ip_clk_freq_hz || 750 !op_lim_fr->min_pll_op_clk_freq_hz || 751 !op_lim_fr->max_pll_op_clk_freq_hz || 752 !op_lim_bk->max_sys_clk_div || !op_lim_fr->max_pll_multiplier) 753 return -EINVAL; 754 755 /* 756 * Make sure op_pix_clk_div will be integer --- unless flexible 757 * op_pix_clk_div is supported 758 */ 759 if (!(pll->flags & CCS_PLL_FLAG_FLEXIBLE_OP_PIX_CLK_DIV) && 760 (pll->bits_per_pixel * pll->op_lanes) % 761 (pll->csi2.lanes * l << op_pix_ddr(pll->flags))) { 762 dev_dbg(dev, "op_pix_clk_div not an integer (bpp %u, op lanes %u, lanes %u, l %u)\n", 763 pll->bits_per_pixel, pll->op_lanes, pll->csi2.lanes, l); 764 return -EINVAL; 765 } 766 767 dev_dbg(dev, "vt_lanes: %u\n", pll->vt_lanes); 768 dev_dbg(dev, "op_lanes: %u\n", pll->op_lanes); 769 770 dev_dbg(dev, "binning: %ux%u\n", pll->binning_horizontal, 771 pll->binning_vertical); 772 773 switch (pll->bus_type) { 774 case CCS_PLL_BUS_TYPE_CSI2_DPHY: 775 case CCS_PLL_BUS_TYPE_CSI2_CPHY: 776 op_sys_clk_freq_hz_sdr = pll->link_freq * 2 777 * (pll->flags & CCS_PLL_FLAG_LANE_SPEED_MODEL ? 778 1 : pll->csi2.lanes); 779 break; 780 default: 781 return -EINVAL; 782 } 783 784 pll->pixel_rate_csi = 785 div_u64((uint64_t)op_sys_clk_freq_hz_sdr 786 * (pll->flags & CCS_PLL_FLAG_LANE_SPEED_MODEL ? 787 pll->csi2.lanes : 1) * PHY_CONST_DIV, 788 phy_const * pll->bits_per_pixel * l); 789 790 /* Figure out limits for OP pre-pll divider based on extclk */ 791 dev_dbg(dev, "min / max op_pre_pll_clk_div: %u / %u\n", 792 op_lim_fr->min_pre_pll_clk_div, op_lim_fr->max_pre_pll_clk_div); 793 max_op_pre_pll_clk_div = 794 min_t(u16, op_lim_fr->max_pre_pll_clk_div, 795 clk_div_even(pll->ext_clk_freq_hz / 796 op_lim_fr->min_pll_ip_clk_freq_hz)); 797 min_op_pre_pll_clk_div = 798 max_t(u16, op_lim_fr->min_pre_pll_clk_div, 799 clk_div_even_up( 800 DIV_ROUND_UP(pll->ext_clk_freq_hz, 801 op_lim_fr->max_pll_ip_clk_freq_hz))); 802 dev_dbg(dev, "pre-pll check: min / max op_pre_pll_clk_div: %u / %u\n", 803 min_op_pre_pll_clk_div, max_op_pre_pll_clk_div); 804 805 i = gcd(op_sys_clk_freq_hz_sdr, 806 pll->ext_clk_freq_hz << op_pix_ddr(pll->flags)); 807 mul = op_sys_clk_freq_hz_sdr / i; 808 div = (pll->ext_clk_freq_hz << op_pix_ddr(pll->flags)) / i; 809 dev_dbg(dev, "mul %u / div %u\n", mul, div); 810 811 min_op_pre_pll_clk_div = 812 max_t(u16, min_op_pre_pll_clk_div, 813 clk_div_even_up( 814 mul / 815 one_or_more( 816 DIV_ROUND_UP(op_lim_fr->max_pll_op_clk_freq_hz, 817 pll->ext_clk_freq_hz)))); 818 dev_dbg(dev, "pll_op check: min / max op_pre_pll_clk_div: %u / %u\n", 819 min_op_pre_pll_clk_div, max_op_pre_pll_clk_div); 820 821 for (op_pll_fr->pre_pll_clk_div = min_op_pre_pll_clk_div; 822 op_pll_fr->pre_pll_clk_div <= max_op_pre_pll_clk_div; 823 op_pll_fr->pre_pll_clk_div += 824 (pll->flags & CCS_PLL_FLAG_EXT_IP_PLL_DIVIDER) ? 1 : 825 2 - (op_pll_fr->pre_pll_clk_div & 1)) { 826 rval = ccs_pll_calculate_op(dev, lim, op_lim_fr, op_lim_bk, pll, 827 op_pll_fr, op_pll_bk, mul, div, 828 op_sys_clk_freq_hz_sdr, l, cphy, 829 phy_const); 830 if (rval) 831 continue; 832 833 rval = check_fr_bounds(dev, lim, pll, 834 pll->flags & CCS_PLL_FLAG_DUAL_PLL ? 835 PLL_OP : PLL_VT); 836 if (rval) 837 continue; 838 839 rval = check_bk_bounds(dev, lim, pll, PLL_OP); 840 if (rval) 841 continue; 842 843 if (pll->flags & CCS_PLL_FLAG_DUAL_PLL) 844 break; 845 846 ccs_pll_calculate_vt(dev, lim, op_lim_bk, pll, op_pll_fr, 847 op_pll_bk, cphy, phy_const); 848 849 rval = check_bk_bounds(dev, lim, pll, PLL_VT); 850 if (rval) 851 continue; 852 rval = check_ext_bounds(dev, pll); 853 if (rval) 854 continue; 855 856 break; 857 } 858 859 if (rval) { 860 dev_dbg(dev, "unable to compute pre_pll divisor\n"); 861 862 return rval; 863 } 864 865 if (pll->flags & CCS_PLL_FLAG_DUAL_PLL) { 866 rval = ccs_pll_calculate_vt_tree(dev, lim, pll); 867 868 if (rval) 869 return rval; 870 } 871 872 print_pll(dev, pll); 873 874 return 0; 875} 876EXPORT_SYMBOL_GPL(ccs_pll_calculate); 877 878MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>"); 879MODULE_DESCRIPTION("Generic MIPI CCS/SMIA/SMIA++ PLL calculator"); 880MODULE_LICENSE("GPL"); 881