drivers/clk/rockchip/clk.c

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