drivers/clk/rockchip/clk.c

   1 /*
   2  * Copyright (c) 2014 MundoReader S.L.
   3  * Author: Heiko Stuebner <heiko@sntech.de>
   4  *
   5  * Copyright (c) 2016 Rockchip Electronics Co. Ltd.
   6  * Author: Xing Zheng <zhengxing@rock-chips.com>
   7  *
   8  * based on
   9  *
  10  * samsung/clk.c
  11  * Copyright (c) 2013 Samsung Electronics Co., Ltd.
  12  * Copyright (c) 2013 Linaro Ltd.
  13  * Author: Thomas Abraham <thomas.ab@samsung.com>
  14  *
  15  * This program is free software; you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2 of the License, or
  18  * (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  * GNU General Public License for more details.
  24  */
  25
  26 #include <linux/slab.h>
  27 #include <linux/clk.h>
  28 #include <linux/clk-provider.h>
  29 #include <linux/mfd/syscon.h>
  30 #include <linux/regmap.h>
  31 #include <linux/reboot.h>
  32 #include "clk.h"
  33
  34 /**
  35  * Register a clock branch.
  36  * Most clock branches have a form like
  37  *
  38  * src1 --|--\
  39  *        |M |--[GATE]-[DIV]-
  40  * src2 --|--/
  41  *
  42  * sometimes without one of those components.
  43  */
  44 static struct clk *rockchip_clk_register_branch(const char *name,
  45                 const char *const *parent_names, u8 num_parents,
  46                 void __iomem *base,
  47                 int muxdiv_offset, u8 mux_shift, u8 mux_width, u8 mux_flags,
  48                 u8 div_shift, u8 div_width, u8 div_flags,
  49                 struct clk_div_table *div_table, int gate_offset,
  50                 u8 gate_shift, u8 gate_flags, unsigned long flags,
  51                 spinlock_t *lock)
  52 {
  53         struct clk *clk;
  54         struct clk_mux *mux = NULL;
  55         struct clk_gate *gate = NULL;
  56         struct clk_divider *div = NULL;
  57         const struct clk_ops *mux_ops = NULL, *div_ops = NULL,
  58                              *gate_ops = NULL;
  59
  60         if (num_parents > 1) {
  61                 mux = kzalloc(sizeof(*mux), GFP_KERNEL);
  62                 if (!mux)
  63                         return ERR_PTR(-ENOMEM);
  64
  65                 mux->reg = base + muxdiv_offset;
  66                 mux->shift = mux_shift;
  67                 mux->mask = BIT(mux_width) - 1;
  68                 mux->flags = mux_flags;
  69                 mux->lock = lock;
  70                 mux_ops = (mux_flags & CLK_MUX_READ_ONLY) ? &clk_mux_ro_ops
  71                                                         : &clk_mux_ops;
  72         }
  73
  74         if (gate_offset >= 0) {
  75                 gate = kzalloc(sizeof(*gate), GFP_KERNEL);
  76                 if (!gate)
  77                         goto err_gate;
  78
  79                 gate->flags = gate_flags;
  80                 gate->reg = base + gate_offset;
  81                 gate->bit_idx = gate_shift;
  82                 gate->lock = lock;
  83                 gate_ops = &clk_gate_ops;
  84         }
  85
  86         if (div_width > 0) {
  87                 div = kzalloc(sizeof(*div), GFP_KERNEL);
  88                 if (!div)
  89                         goto err_div;
  90
  91                 div->flags = div_flags;
  92                 div->reg = base + muxdiv_offset;
  93                 div->shift = div_shift;
  94                 div->width = div_width;
  95                 div->lock = lock;
  96                 div->table = div_table;
  97                 div_ops = (div_flags & CLK_DIVIDER_READ_ONLY)
  98                                                 ? &clk_divider_ro_ops
  99                                                 : &clk_divider_ops;
 100         }
 101
 102         clk = clk_register_composite(NULL, name, parent_names, num_parents,
 103                                      mux ? &mux->hw : NULL, mux_ops,
 104                                      div ? &div->hw : NULL, div_ops,
 105                                      gate ? &gate->hw : NULL, gate_ops,
 106                                      flags);
 107
 108         return clk;
 109 err_div:
 110         kfree(gate);
 111 err_gate:
 112         kfree(mux);
 113         return ERR_PTR(-ENOMEM);
 114 }
 115
 116 struct rockchip_clk_frac {
 117         struct notifier_block                   clk_nb;
 118         struct clk_fractional_divider           div;
 119         struct clk_gate                         gate;
 120
 121         struct clk_mux                          mux;
 122         const struct clk_ops                    *mux_ops;
 123         int                                     mux_frac_idx;
 124
 125         bool                                    rate_change_remuxed;
 126         int                                     rate_change_idx;
 127 };
 128
 129 #define to_rockchip_clk_frac_nb(nb) \
 130                         container_of(nb, struct rockchip_clk_frac, clk_nb)
 131
 132 static int rockchip_clk_frac_notifier_cb(struct notifier_block *nb,
 133                                          unsigned long event, void *data)
 134 {
 135         struct clk_notifier_data *ndata = data;
 136         struct rockchip_clk_frac *frac = to_rockchip_clk_frac_nb(nb);
 137         struct clk_mux *frac_mux = &frac->mux;
 138         int ret = 0;
 139
 140         pr_debug("%s: event %lu, old_rate %lu, new_rate: %lu\n",
 141                  __func__, event, ndata->old_rate, ndata->new_rate);
 142         if (event == PRE_RATE_CHANGE) {
 143                 frac->rate_change_idx =
 144                                 frac->mux_ops->get_parent(&frac_mux->hw);
 145                 if (frac->rate_change_idx != frac->mux_frac_idx) {
 146                         frac->mux_ops->set_parent(&frac_mux->hw,
 147                                                   frac->mux_frac_idx);
 148                         frac->rate_change_remuxed = 1;
 149                 }
 150         } else if (event == POST_RATE_CHANGE) {
 151                 /*
 152                  * The POST_RATE_CHANGE notifier runs directly after the
 153                  * divider clock is set in clk_change_rate, so we'll have
 154                  * remuxed back to the original parent before clk_change_rate
 155                  * reaches the mux itself.
 156                  */
 157                 if (frac->rate_change_remuxed) {
 158                         frac->mux_ops->set_parent(&frac_mux->hw,
 159                                                   frac->rate_change_idx);
 160                         frac->rate_change_remuxed = 0;
 161                 }
 162         }
 163
 164         return notifier_from_errno(ret);
 165 }
 166
 167 static struct clk *rockchip_clk_register_frac_branch(
 168                 struct rockchip_clk_provider *ctx, const char *name,
 169                 const char *const *parent_names, u8 num_parents,
 170                 void __iomem *base, int muxdiv_offset, u8 div_flags,
 171                 int gate_offset, u8 gate_shift, u8 gate_flags,
 172                 unsigned long flags, struct rockchip_clk_branch *child,
 173                 spinlock_t *lock)
 174 {
 175         struct rockchip_clk_frac *frac;
 176         struct clk *clk;
 177         struct clk_gate *gate = NULL;
 178         struct clk_fractional_divider *div = NULL;
 179         const struct clk_ops *div_ops = NULL, *gate_ops = NULL;
 180
 181         if (muxdiv_offset < 0)
 182                 return ERR_PTR(-EINVAL);
 183
 184         if (child && child->branch_type != branch_mux) {
 185                 pr_err("%s: fractional child clock for %s can only be a mux\n",
 186                        __func__, name);
 187                 return ERR_PTR(-EINVAL);
 188         }
 189
 190         frac = kzalloc(sizeof(*frac), GFP_KERNEL);
 191         if (!frac)
 192                 return ERR_PTR(-ENOMEM);
 193
 194         if (gate_offset >= 0) {
 195                 gate = &frac->gate;
 196                 gate->flags = gate_flags;
 197                 gate->reg = base + gate_offset;
 198                 gate->bit_idx = gate_shift;
 199                 gate->lock = lock;
 200                 gate_ops = &clk_gate_ops;
 201         }
 202
 203         div = &frac->div;
 204         div->flags = div_flags;
 205         div->reg = base + muxdiv_offset;
 206         div->mshift = 16;
 207         div->mwidth = 16;
 208         div->mmask = GENMASK(div->mwidth - 1, 0) << div->mshift;
 209         div->nshift = 0;
 210         div->nwidth = 16;
 211         div->nmask = GENMASK(div->nwidth - 1, 0) << div->nshift;
 212         div->lock = lock;
 213         div_ops = &clk_fractional_divider_ops;
 214
 215         clk = clk_register_composite(NULL, name, parent_names, num_parents,
 216                                      NULL, NULL,
 217                                      &div->hw, div_ops,
 218                                      gate ? &gate->hw : NULL, gate_ops,
 219                                      flags | CLK_SET_RATE_UNGATE);
 220         if (IS_ERR(clk)) {
 221                 kfree(frac);
 222                 return clk;
 223         }
 224
 225         if (child) {
 226                 struct clk_mux *frac_mux = &frac->mux;
 227                 struct clk_init_data init;
 228                 struct clk *mux_clk;
 229                 int i, ret;
 230
 231                 frac->mux_frac_idx = -1;
 232                 for (i = 0; i < child->num_parents; i++) {
 233                         if (!strcmp(name, child->parent_names[i])) {
 234                                 pr_debug("%s: found fractional parent in mux at pos %d\n",
 235                                          __func__, i);
 236                                 frac->mux_frac_idx = i;
 237                                 break;
 238                         }
 239                 }
 240
 241                 frac->mux_ops = &clk_mux_ops;
 242                 frac->clk_nb.notifier_call = rockchip_clk_frac_notifier_cb;
 243
 244                 frac_mux->reg = base + child->muxdiv_offset;
 245                 frac_mux->shift = child->mux_shift;
 246                 frac_mux->mask = BIT(child->mux_width) - 1;
 247                 frac_mux->flags = child->mux_flags;
 248                 frac_mux->lock = lock;
 249                 frac_mux->hw.init = &init;
 250
 251                 init.name = child->name;
 252                 init.flags = child->flags | CLK_SET_RATE_PARENT;
 253                 init.ops = frac->mux_ops;
 254                 init.parent_names = child->parent_names;
 255                 init.num_parents = child->num_parents;
 256
 257                 mux_clk = clk_register(NULL, &frac_mux->hw);
 258                 if (IS_ERR(mux_clk))
 259                         return clk;
 260
 261                 rockchip_clk_add_lookup(ctx, mux_clk, child->id);
 262
 263                 /* notifier on the fraction divider to catch rate changes */
 264                 if (frac->mux_frac_idx >= 0) {
 265                         ret = clk_notifier_register(clk, &frac->clk_nb);
 266                         if (ret)
 267                                 pr_err("%s: failed to register clock notifier for %s\n",
 268                                                 __func__, name);
 269                 } else {
 270                         pr_warn("%s: could not find %s as parent of %s, rate changes may not work\n",
 271                                 __func__, name, child->name);
 272                 }
 273         }
 274
 275         return clk;
 276 }
 277
 278 static struct clk *rockchip_clk_register_factor_branch(const char *name,
 279                 const char *const *parent_names, u8 num_parents,
 280                 void __iomem *base, unsigned int mult, unsigned int div,
 281                 int gate_offset, u8 gate_shift, u8 gate_flags,
 282                 unsigned long flags, spinlock_t *lock)
 283 {
 284         struct clk *clk;
 285         struct clk_gate *gate = NULL;
 286         struct clk_fixed_factor *fix = NULL;
 287
 288         /* without gate, register a simple factor clock */
 289         if (gate_offset == 0) {
 290                 return clk_register_fixed_factor(NULL, name,
 291                                 parent_names[0], flags, mult,
 292                                 div);
 293         }
 294
 295         gate = kzalloc(sizeof(*gate), GFP_KERNEL);
 296         if (!gate)
 297                 return ERR_PTR(-ENOMEM);
 298
 299         gate->flags = gate_flags;
 300         gate->reg = base + gate_offset;
 301         gate->bit_idx = gate_shift;
 302         gate->lock = lock;
 303
 304         fix = kzalloc(sizeof(*fix), GFP_KERNEL);
 305         if (!fix) {
 306                 kfree(gate);
 307                 return ERR_PTR(-ENOMEM);
 308         }
 309
 310         fix->mult = mult;
 311         fix->div = div;
 312
 313         clk = clk_register_composite(NULL, name, parent_names, num_parents,
 314                                      NULL, NULL,
 315                                      &fix->hw, &clk_fixed_factor_ops,
 316                                      &gate->hw, &clk_gate_ops, flags);
 317         if (IS_ERR(clk)) {
 318                 kfree(fix);
 319                 kfree(gate);
 320         }
 321
 322         return clk;
 323 }
 324
 325 struct rockchip_clk_provider * __init rockchip_clk_init(struct device_node *np,
 326                         void __iomem *base, unsigned long nr_clks)
 327 {
 328         struct rockchip_clk_provider *ctx;
 329         struct clk **clk_table;
 330         int i;
 331
 332         ctx = kzalloc(sizeof(struct rockchip_clk_provider), GFP_KERNEL);
 333         if (!ctx)
 334                 return ERR_PTR(-ENOMEM);
 335
 336         clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL);
 337         if (!clk_table)
 338                 goto err_free;
 339
 340         for (i = 0; i < nr_clks; ++i)
 341                 clk_table[i] = ERR_PTR(-ENOENT);
 342
 343         ctx->reg_base = base;
 344         ctx->clk_data.clks = clk_table;
 345         ctx->clk_data.clk_num = nr_clks;
 346         ctx->cru_node = np;
 347         ctx->grf = ERR_PTR(-EPROBE_DEFER);
 348         spin_lock_init(&ctx->lock);
 349
 350         ctx->grf = syscon_regmap_lookup_by_phandle(ctx->cru_node,
 351                                                    "rockchip,grf");
 352
 353         return ctx;
 354
 355 err_free:
 356         kfree(ctx);
 357         return ERR_PTR(-ENOMEM);
 358 }
 359
 360 void __init rockchip_clk_of_add_provider(struct device_node *np,
 361                                 struct rockchip_clk_provider *ctx)
 362 {
 363         if (of_clk_add_provider(np, of_clk_src_onecell_get,
 364                                 &ctx->clk_data))
 365                 pr_err("%s: could not register clk provider\n", __func__);
 366 }
 367
 368 void rockchip_clk_add_lookup(struct rockchip_clk_provider *ctx,
 369                              struct clk *clk, unsigned int id)
 370 {
 371         if (ctx->clk_data.clks && id)
 372                 ctx->clk_data.clks[id] = clk;
 373 }
 374
 375 void __init rockchip_clk_register_plls(struct rockchip_clk_provider *ctx,
 376                                 struct rockchip_pll_clock *list,
 377                                 unsigned int nr_pll, int grf_lock_offset)
 378 {
 379         struct clk *clk;
 380         int idx;
 381
 382         for (idx = 0; idx < nr_pll; idx++, list++) {
 383                 clk = rockchip_clk_register_pll(ctx, list->type, list->name,
 384                                 list->parent_names, list->num_parents,
 385                                 list->con_offset, grf_lock_offset,
 386                                 list->lock_shift, list->mode_offset,
 387                                 list->mode_shift, list->rate_table,
 388                                 list->pll_flags);
 389                 if (IS_ERR(clk)) {
 390                         pr_err("%s: failed to register clock %s\n", __func__,
 391                                 list->name);
 392                         continue;
 393                 }
 394
 395                 rockchip_clk_add_lookup(ctx, clk, list->id);
 396         }
 397 }
 398
 399 void __init rockchip_clk_register_branches(
 400                                       struct rockchip_clk_provider *ctx,
 401                                       struct rockchip_clk_branch *list,
 402                                       unsigned int nr_clk)
 403 {
 404         struct clk *clk = NULL;
 405         unsigned int idx;
 406         unsigned long flags;
 407
 408         for (idx = 0; idx < nr_clk; idx++, list++) {
 409                 flags = list->flags;
 410
 411                 /* catch simple muxes */
 412                 switch (list->branch_type) {
 413                 case branch_mux:
 414                         clk = clk_register_mux(NULL, list->name,
 415                                 list->parent_names, list->num_parents,
 416                                 flags, ctx->reg_base + list->muxdiv_offset,
 417                                 list->mux_shift, list->mux_width,
 418                                 list->mux_flags, &ctx->lock);
 419                         break;
 420                 case branch_divider:
 421                         if (list->div_table)
 422                                 clk = clk_register_divider_table(NULL,
 423                                         list->name, list->parent_names[0],
 424                                         flags,
 425                                         ctx->reg_base + list->muxdiv_offset,
 426                                         list->div_shift, list->div_width,
 427                                         list->div_flags, list->div_table,
 428                                         &ctx->lock);
 429                         else
 430                                 clk = clk_register_divider(NULL, list->name,
 431                                         list->parent_names[0], flags,
 432                                         ctx->reg_base + list->muxdiv_offset,
 433                                         list->div_shift, list->div_width,
 434                                         list->div_flags, &ctx->lock);
 435                         break;
 436                 case branch_fraction_divider:
 437                         clk = rockchip_clk_register_frac_branch(ctx, list->name,
 438                                 list->parent_names, list->num_parents,
 439                                 ctx->reg_base, list->muxdiv_offset,
 440                                 list->div_flags,
 441                                 list->gate_offset, list->gate_shift,
 442                                 list->gate_flags, flags, list->child,
 443                                 &ctx->lock);
 444                         break;
 445                 case branch_gate:
 446                         flags |= CLK_SET_RATE_PARENT;
 447
 448                         clk = clk_register_gate(NULL, list->name,
 449                                 list->parent_names[0], flags,
 450                                 ctx->reg_base + list->gate_offset,
 451                                 list->gate_shift, list->gate_flags, &ctx->lock);
 452                         break;
 453                 case branch_composite:
 454                         clk = rockchip_clk_register_branch(list->name,
 455                                 list->parent_names, list->num_parents,
 456                                 ctx->reg_base, list->muxdiv_offset,
 457                                 list->mux_shift,
 458                                 list->mux_width, list->mux_flags,
 459                                 list->div_shift, list->div_width,
 460                                 list->div_flags, list->div_table,
 461                                 list->gate_offset, list->gate_shift,
 462                                 list->gate_flags, flags, &ctx->lock);
 463                         break;
 464                 case branch_mmc:
 465                         clk = rockchip_clk_register_mmc(
 466                                 list->name,
 467                                 list->parent_names, list->num_parents,
 468                                 ctx->reg_base + list->muxdiv_offset,
 469                                 list->div_shift
 470                         );
 471                         break;
 472                 case branch_inverter:
 473                         clk = rockchip_clk_register_inverter(
 474                                 list->name, list->parent_names,
 475                                 list->num_parents,
 476                                 ctx->reg_base + list->muxdiv_offset,
 477                                 list->div_shift, list->div_flags, &ctx->lock);
 478                         break;
 479                 case branch_factor:
 480                         clk = rockchip_clk_register_factor_branch(
 481                                 list->name, list->parent_names,
 482                                 list->num_parents, ctx->reg_base,
 483                                 list->div_shift, list->div_width,
 484                                 list->gate_offset, list->gate_shift,
 485                                 list->gate_flags, flags, &ctx->lock);
 486                         break;
 487                 }
 488
 489                 /* none of the cases above matched */
 490                 if (!clk) {
 491                         pr_err("%s: unknown clock type %d\n",
 492                                __func__, list->branch_type);
 493                         continue;
 494                 }
 495
 496                 if (IS_ERR(clk)) {
 497                         pr_err("%s: failed to register clock %s: %ld\n",
 498                                __func__, list->name, PTR_ERR(clk));
 499                         continue;
 500                 }
 501
 502                 rockchip_clk_add_lookup(ctx, clk, list->id);
 503         }
 504 }
 505
 506 void __init rockchip_clk_register_armclk(struct rockchip_clk_provider *ctx,
 507                         unsigned int lookup_id,
 508                         const char *name, const char *const *parent_names,
 509                         u8 num_parents,
 510                         const struct rockchip_cpuclk_reg_data *reg_data,
 511                         const struct rockchip_cpuclk_rate_table *rates,
 512                         int nrates)
 513 {
 514         struct clk *clk;
 515
 516         clk = rockchip_clk_register_cpuclk(name, parent_names, num_parents,
 517                                            reg_data, rates, nrates,
 518                                            ctx->reg_base, &ctx->lock);
 519         if (IS_ERR(clk)) {
 520                 pr_err("%s: failed to register clock %s: %ld\n",
 521                        __func__, name, PTR_ERR(clk));
 522                 return;
 523         }
 524
 525         rockchip_clk_add_lookup(ctx, clk, lookup_id);
 526 }
 527
 528 void __init rockchip_clk_protect_critical(const char *const clocks[],
 529                                           int nclocks)
 530 {
 531         int i;
 532
 533         /* Protect the clocks that needs to stay on */
 534         for (i = 0; i < nclocks; i++) {
 535                 struct clk *clk = __clk_lookup(clocks[i]);
 536
 537                 if (clk)
 538                         clk_prepare_enable(clk);
 539         }
 540 }
 541
 542 static void __iomem *rst_base;
 543 static unsigned int reg_restart;
 544 static void (*cb_restart)(void);
 545 static int rockchip_restart_notify(struct notifier_block *this,
 546                                    unsigned long mode, void *cmd)
 547 {
 548         if (cb_restart)
 549                 cb_restart();
 550
 551         writel(0xfdb9, rst_base + reg_restart);
 552         return NOTIFY_DONE;
 553 }
 554
 555 static struct notifier_block rockchip_restart_handler = {
 556         .notifier_call = rockchip_restart_notify,
 557         .priority = 128,
 558 };
 559
 560 void __init
 561 rockchip_register_restart_notifier(struct rockchip_clk_provider *ctx,
 562                                                unsigned int reg,
 563                                                void (*cb)(void))
 564 {
 565         int ret;
 566
 567         rst_base = ctx->reg_base;
 568         reg_restart = reg;
 569         cb_restart = cb;
 570         ret = register_restart_handler(&rockchip_restart_handler);
 571         if (ret)
 572                 pr_err("%s: cannot register restart handler, %d\n",
 573                        __func__, ret);
 574 }