linux/drivers/clk/rockchip/clk.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (c) 2014 MundoReader S.L.
   4 * Author: Heiko Stuebner <heiko@sntech.de>
   5 *
   6 * Copyright (c) 2016 Rockchip Electronics Co. Ltd.
   7 * Author: Xing Zheng <zhengxing@rock-chips.com>
   8 *
   9 * based on
  10 *
  11 * samsung/clk.c
  12 * Copyright (c) 2013 Samsung Electronics Co., Ltd.
  13 * Copyright (c) 2013 Linaro Ltd.
  14 * Author: Thomas Abraham <thomas.ab@samsung.com>
  15 */
  16
  17#include <linux/slab.h>
  18#include <linux/clk.h>
  19#include <linux/clk-provider.h>
  20#include <linux/io.h>
  21#include <linux/mfd/syscon.h>
  22#include <linux/regmap.h>
  23#include <linux/reboot.h>
  24#include <linux/rational.h>
  25#include "clk.h"
  26
  27/**
  28 * Register a clock branch.
  29 * Most clock branches have a form like
  30 *
  31 * src1 --|--\
  32 *        |M |--[GATE]-[DIV]-
  33 * src2 --|--/
  34 *
  35 * sometimes without one of those components.
  36 */
  37static struct clk *rockchip_clk_register_branch(const char *name,
  38                const char *const *parent_names, u8 num_parents,
  39                void __iomem *base,
  40                int muxdiv_offset, u8 mux_shift, u8 mux_width, u8 mux_flags,
  41                int div_offset, u8 div_shift, u8 div_width, u8 div_flags,
  42                struct clk_div_table *div_table, int gate_offset,
  43                u8 gate_shift, u8 gate_flags, unsigned long flags,
  44                spinlock_t *lock)
  45{
  46        struct clk *clk;
  47        struct clk_mux *mux = NULL;
  48        struct clk_gate *gate = NULL;
  49        struct clk_divider *div = NULL;
  50        const struct clk_ops *mux_ops = NULL, *div_ops = NULL,
  51                             *gate_ops = NULL;
  52        int ret;
  53
  54        if (num_parents > 1) {
  55                mux = kzalloc(sizeof(*mux), GFP_KERNEL);
  56                if (!mux)
  57                        return ERR_PTR(-ENOMEM);
  58
  59                mux->reg = base + muxdiv_offset;
  60                mux->shift = mux_shift;
  61                mux->mask = BIT(mux_width) - 1;
  62                mux->flags = mux_flags;
  63                mux->lock = lock;
  64                mux_ops = (mux_flags & CLK_MUX_READ_ONLY) ? &clk_mux_ro_ops
  65                                                        : &clk_mux_ops;
  66        }
  67
  68        if (gate_offset >= 0) {
  69                gate = kzalloc(sizeof(*gate), GFP_KERNEL);
  70                if (!gate) {
  71                        ret = -ENOMEM;
  72                        goto err_gate;
  73                }
  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                        ret = -ENOMEM;
  86                        goto err_div;
  87                }
  88
  89                div->flags = div_flags;
  90                if (div_offset)
  91                        div->reg = base + div_offset;
  92                else
  93                        div->reg = base + muxdiv_offset;
  94                div->shift = div_shift;
  95                div->width = div_width;
  96                div->lock = lock;
  97                div->table = div_table;
  98                div_ops = (div_flags & CLK_DIVIDER_READ_ONLY)
  99                                                ? &clk_divider_ro_ops
 100                                                : &clk_divider_ops;
 101        }
 102
 103        clk = clk_register_composite(NULL, name, parent_names, num_parents,
 104                                     mux ? &mux->hw : NULL, mux_ops,
 105                                     div ? &div->hw : NULL, div_ops,
 106                                     gate ? &gate->hw : NULL, gate_ops,
 107                                     flags);
 108
 109        if (IS_ERR(clk)) {
 110                ret = PTR_ERR(clk);
 111                goto err_composite;
 112        }
 113
 114        return clk;
 115err_composite:
 116        kfree(div);
 117err_div:
 118        kfree(gate);
 119err_gate:
 120        kfree(mux);
 121        return ERR_PTR(ret);
 122}
 123
 124struct rockchip_clk_frac {
 125        struct notifier_block                   clk_nb;
 126        struct clk_fractional_divider           div;
 127        struct clk_gate                         gate;
 128
 129        struct clk_mux                          mux;
 130        const struct clk_ops                    *mux_ops;
 131        int                                     mux_frac_idx;
 132
 133        bool                                    rate_change_remuxed;
 134        int                                     rate_change_idx;
 135};
 136
 137#define to_rockchip_clk_frac_nb(nb) \
 138                        container_of(nb, struct rockchip_clk_frac, clk_nb)
 139
 140static int rockchip_clk_frac_notifier_cb(struct notifier_block *nb,
 141                                         unsigned long event, void *data)
 142{
 143        struct clk_notifier_data *ndata = data;
 144        struct rockchip_clk_frac *frac = to_rockchip_clk_frac_nb(nb);
 145        struct clk_mux *frac_mux = &frac->mux;
 146        int ret = 0;
 147
 148        pr_debug("%s: event %lu, old_rate %lu, new_rate: %lu\n",
 149                 __func__, event, ndata->old_rate, ndata->new_rate);
 150        if (event == PRE_RATE_CHANGE) {
 151                frac->rate_change_idx =
 152                                frac->mux_ops->get_parent(&frac_mux->hw);
 153                if (frac->rate_change_idx != frac->mux_frac_idx) {
 154                        frac->mux_ops->set_parent(&frac_mux->hw,
 155                                                  frac->mux_frac_idx);
 156                        frac->rate_change_remuxed = 1;
 157                }
 158        } else if (event == POST_RATE_CHANGE) {
 159                /*
 160                 * The POST_RATE_CHANGE notifier runs directly after the
 161                 * divider clock is set in clk_change_rate, so we'll have
 162                 * remuxed back to the original parent before clk_change_rate
 163                 * reaches the mux itself.
 164                 */
 165                if (frac->rate_change_remuxed) {
 166                        frac->mux_ops->set_parent(&frac_mux->hw,
 167                                                  frac->rate_change_idx);
 168                        frac->rate_change_remuxed = 0;
 169                }
 170        }
 171
 172        return notifier_from_errno(ret);
 173}
 174
 175/**
 176 * fractional divider must set that denominator is 20 times larger than
 177 * numerator to generate precise clock frequency.
 178 */
 179static void rockchip_fractional_approximation(struct clk_hw *hw,
 180                unsigned long rate, unsigned long *parent_rate,
 181                unsigned long *m, unsigned long *n)
 182{
 183        struct clk_fractional_divider *fd = to_clk_fd(hw);
 184        unsigned long p_rate, p_parent_rate;
 185        struct clk_hw *p_parent;
 186        unsigned long scale;
 187
 188        p_rate = clk_hw_get_rate(clk_hw_get_parent(hw));
 189        if ((rate * 20 > p_rate) && (p_rate % rate != 0)) {
 190                p_parent = clk_hw_get_parent(clk_hw_get_parent(hw));
 191                p_parent_rate = clk_hw_get_rate(p_parent);
 192                *parent_rate = p_parent_rate;
 193        }
 194
 195        /*
 196         * Get rate closer to *parent_rate to guarantee there is no overflow
 197         * for m and n. In the result it will be the nearest rate left shifted
 198         * by (scale - fd->nwidth) bits.
 199         */
 200        scale = fls_long(*parent_rate / rate - 1);
 201        if (scale > fd->nwidth)
 202                rate <<= scale - fd->nwidth;
 203
 204        rational_best_approximation(rate, *parent_rate,
 205                        GENMASK(fd->mwidth - 1, 0), GENMASK(fd->nwidth - 1, 0),
 206                        m, n);
 207}
 208
 209static struct clk *rockchip_clk_register_frac_branch(
 210                struct rockchip_clk_provider *ctx, const char *name,
 211                const char *const *parent_names, u8 num_parents,
 212                void __iomem *base, int muxdiv_offset, u8 div_flags,
 213                int gate_offset, u8 gate_shift, u8 gate_flags,
 214                unsigned long flags, struct rockchip_clk_branch *child,
 215                spinlock_t *lock)
 216{
 217        struct rockchip_clk_frac *frac;
 218        struct clk *clk;
 219        struct clk_gate *gate = NULL;
 220        struct clk_fractional_divider *div = NULL;
 221        const struct clk_ops *div_ops = NULL, *gate_ops = NULL;
 222
 223        if (muxdiv_offset < 0)
 224                return ERR_PTR(-EINVAL);
 225
 226        if (child && child->branch_type != branch_mux) {
 227                pr_err("%s: fractional child clock for %s can only be a mux\n",
 228                       __func__, name);
 229                return ERR_PTR(-EINVAL);
 230        }
 231
 232        frac = kzalloc(sizeof(*frac), GFP_KERNEL);
 233        if (!frac)
 234                return ERR_PTR(-ENOMEM);
 235
 236        if (gate_offset >= 0) {
 237                gate = &frac->gate;
 238                gate->flags = gate_flags;
 239                gate->reg = base + gate_offset;
 240                gate->bit_idx = gate_shift;
 241                gate->lock = lock;
 242                gate_ops = &clk_gate_ops;
 243        }
 244
 245        div = &frac->div;
 246        div->flags = div_flags;
 247        div->reg = base + muxdiv_offset;
 248        div->mshift = 16;
 249        div->mwidth = 16;
 250        div->mmask = GENMASK(div->mwidth - 1, 0) << div->mshift;
 251        div->nshift = 0;
 252        div->nwidth = 16;
 253        div->nmask = GENMASK(div->nwidth - 1, 0) << div->nshift;
 254        div->lock = lock;
 255        div->approximation = rockchip_fractional_approximation;
 256        div_ops = &clk_fractional_divider_ops;
 257
 258        clk = clk_register_composite(NULL, name, parent_names, num_parents,
 259                                     NULL, NULL,
 260                                     &div->hw, div_ops,
 261                                     gate ? &gate->hw : NULL, gate_ops,
 262                                     flags | CLK_SET_RATE_UNGATE);
 263        if (IS_ERR(clk)) {
 264                kfree(frac);
 265                return clk;
 266        }
 267
 268        if (child) {
 269                struct clk_mux *frac_mux = &frac->mux;
 270                struct clk_init_data init;
 271                struct clk *mux_clk;
 272                int ret;
 273
 274                frac->mux_frac_idx = match_string(child->parent_names,
 275                                                  child->num_parents, name);
 276                frac->mux_ops = &clk_mux_ops;
 277                frac->clk_nb.notifier_call = rockchip_clk_frac_notifier_cb;
 278
 279                frac_mux->reg = base + child->muxdiv_offset;
 280                frac_mux->shift = child->mux_shift;
 281                frac_mux->mask = BIT(child->mux_width) - 1;
 282                frac_mux->flags = child->mux_flags;
 283                frac_mux->lock = lock;
 284                frac_mux->hw.init = &init;
 285
 286                init.name = child->name;
 287                init.flags = child->flags | CLK_SET_RATE_PARENT;
 288                init.ops = frac->mux_ops;
 289                init.parent_names = child->parent_names;
 290                init.num_parents = child->num_parents;
 291
 292                mux_clk = clk_register(NULL, &frac_mux->hw);
 293                if (IS_ERR(mux_clk)) {
 294                        kfree(frac);
 295                        return clk;
 296                }
 297
 298                rockchip_clk_add_lookup(ctx, mux_clk, child->id);
 299
 300                /* notifier on the fraction divider to catch rate changes */
 301                if (frac->mux_frac_idx >= 0) {
 302                        pr_debug("%s: found fractional parent in mux at pos %d\n",
 303                                 __func__, frac->mux_frac_idx);
 304                        ret = clk_notifier_register(clk, &frac->clk_nb);
 305                        if (ret)
 306                                pr_err("%s: failed to register clock notifier for %s\n",
 307                                                __func__, name);
 308                } else {
 309                        pr_warn("%s: could not find %s as parent of %s, rate changes may not work\n",
 310                                __func__, name, child->name);
 311                }
 312        }
 313
 314        return clk;
 315}
 316
 317static struct clk *rockchip_clk_register_factor_branch(const char *name,
 318                const char *const *parent_names, u8 num_parents,
 319                void __iomem *base, unsigned int mult, unsigned int div,
 320                int gate_offset, u8 gate_shift, u8 gate_flags,
 321                unsigned long flags, spinlock_t *lock)
 322{
 323        struct clk *clk;
 324        struct clk_gate *gate = NULL;
 325        struct clk_fixed_factor *fix = NULL;
 326
 327        /* without gate, register a simple factor clock */
 328        if (gate_offset == 0) {
 329                return clk_register_fixed_factor(NULL, name,
 330                                parent_names[0], flags, mult,
 331                                div);
 332        }
 333
 334        gate = kzalloc(sizeof(*gate), GFP_KERNEL);
 335        if (!gate)
 336                return ERR_PTR(-ENOMEM);
 337
 338        gate->flags = gate_flags;
 339        gate->reg = base + gate_offset;
 340        gate->bit_idx = gate_shift;
 341        gate->lock = lock;
 342
 343        fix = kzalloc(sizeof(*fix), GFP_KERNEL);
 344        if (!fix) {
 345                kfree(gate);
 346                return ERR_PTR(-ENOMEM);
 347        }
 348
 349        fix->mult = mult;
 350        fix->div = div;
 351
 352        clk = clk_register_composite(NULL, name, parent_names, num_parents,
 353                                     NULL, NULL,
 354                                     &fix->hw, &clk_fixed_factor_ops,
 355                                     &gate->hw, &clk_gate_ops, flags);
 356        if (IS_ERR(clk)) {
 357                kfree(fix);
 358                kfree(gate);
 359        }
 360
 361        return clk;
 362}
 363
 364struct rockchip_clk_provider * __init rockchip_clk_init(struct device_node *np,
 365                        void __iomem *base, unsigned long nr_clks)
 366{
 367        struct rockchip_clk_provider *ctx;
 368        struct clk **clk_table;
 369        int i;
 370
 371        ctx = kzalloc(sizeof(struct rockchip_clk_provider), GFP_KERNEL);
 372        if (!ctx)
 373                return ERR_PTR(-ENOMEM);
 374
 375        clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL);
 376        if (!clk_table)
 377                goto err_free;
 378
 379        for (i = 0; i < nr_clks; ++i)
 380                clk_table[i] = ERR_PTR(-ENOENT);
 381
 382        ctx->reg_base = base;
 383        ctx->clk_data.clks = clk_table;
 384        ctx->clk_data.clk_num = nr_clks;
 385        ctx->cru_node = np;
 386        spin_lock_init(&ctx->lock);
 387
 388        ctx->grf = syscon_regmap_lookup_by_phandle(ctx->cru_node,
 389                                                   "rockchip,grf");
 390
 391        return ctx;
 392
 393err_free:
 394        kfree(ctx);
 395        return ERR_PTR(-ENOMEM);
 396}
 397
 398void __init rockchip_clk_of_add_provider(struct device_node *np,
 399                                struct rockchip_clk_provider *ctx)
 400{
 401        if (of_clk_add_provider(np, of_clk_src_onecell_get,
 402                                &ctx->clk_data))
 403                pr_err("%s: could not register clk provider\n", __func__);
 404}
 405
 406void rockchip_clk_add_lookup(struct rockchip_clk_provider *ctx,
 407                             struct clk *clk, unsigned int id)
 408{
 409        if (ctx->clk_data.clks && id)
 410                ctx->clk_data.clks[id] = clk;
 411}
 412
 413void __init rockchip_clk_register_plls(struct rockchip_clk_provider *ctx,
 414                                struct rockchip_pll_clock *list,
 415                                unsigned int nr_pll, int grf_lock_offset)
 416{
 417        struct clk *clk;
 418        int idx;
 419
 420        for (idx = 0; idx < nr_pll; idx++, list++) {
 421                clk = rockchip_clk_register_pll(ctx, list->type, list->name,
 422                                list->parent_names, list->num_parents,
 423                                list->con_offset, grf_lock_offset,
 424                                list->lock_shift, list->mode_offset,
 425                                list->mode_shift, list->rate_table,
 426                                list->flags, list->pll_flags);
 427                if (IS_ERR(clk)) {
 428                        pr_err("%s: failed to register clock %s\n", __func__,
 429                                list->name);
 430                        continue;
 431                }
 432
 433                rockchip_clk_add_lookup(ctx, clk, list->id);
 434        }
 435}
 436
 437void __init rockchip_clk_register_branches(
 438                                      struct rockchip_clk_provider *ctx,
 439                                      struct rockchip_clk_branch *list,
 440                                      unsigned int nr_clk)
 441{
 442        struct clk *clk = NULL;
 443        unsigned int idx;
 444        unsigned long flags;
 445
 446        for (idx = 0; idx < nr_clk; idx++, list++) {
 447                flags = list->flags;
 448
 449                /* catch simple muxes */
 450                switch (list->branch_type) {
 451                case branch_mux:
 452                        clk = clk_register_mux(NULL, list->name,
 453                                list->parent_names, list->num_parents,
 454                                flags, ctx->reg_base + list->muxdiv_offset,
 455                                list->mux_shift, list->mux_width,
 456                                list->mux_flags, &ctx->lock);
 457                        break;
 458                case branch_muxgrf:
 459                        clk = rockchip_clk_register_muxgrf(list->name,
 460                                list->parent_names, list->num_parents,
 461                                flags, ctx->grf, list->muxdiv_offset,
 462                                list->mux_shift, list->mux_width,
 463                                list->mux_flags);
 464                        break;
 465                case branch_divider:
 466                        if (list->div_table)
 467                                clk = clk_register_divider_table(NULL,
 468                                        list->name, list->parent_names[0],
 469                                        flags,
 470                                        ctx->reg_base + list->muxdiv_offset,
 471                                        list->div_shift, list->div_width,
 472                                        list->div_flags, list->div_table,
 473                                        &ctx->lock);
 474                        else
 475                                clk = clk_register_divider(NULL, list->name,
 476                                        list->parent_names[0], flags,
 477                                        ctx->reg_base + list->muxdiv_offset,
 478                                        list->div_shift, list->div_width,
 479                                        list->div_flags, &ctx->lock);
 480                        break;
 481                case branch_fraction_divider:
 482                        clk = rockchip_clk_register_frac_branch(ctx, list->name,
 483                                list->parent_names, list->num_parents,
 484                                ctx->reg_base, list->muxdiv_offset,
 485                                list->div_flags,
 486                                list->gate_offset, list->gate_shift,
 487                                list->gate_flags, flags, list->child,
 488                                &ctx->lock);
 489                        break;
 490                case branch_half_divider:
 491                        clk = rockchip_clk_register_halfdiv(list->name,
 492                                list->parent_names, list->num_parents,
 493                                ctx->reg_base, list->muxdiv_offset,
 494                                list->mux_shift, list->mux_width,
 495                                list->mux_flags, list->div_shift,
 496                                list->div_width, list->div_flags,
 497                                list->gate_offset, list->gate_shift,
 498                                list->gate_flags, flags, &ctx->lock);
 499                        break;
 500                case branch_gate:
 501                        flags |= CLK_SET_RATE_PARENT;
 502
 503                        clk = clk_register_gate(NULL, list->name,
 504                                list->parent_names[0], flags,
 505                                ctx->reg_base + list->gate_offset,
 506                                list->gate_shift, list->gate_flags, &ctx->lock);
 507                        break;
 508                case branch_composite:
 509                        clk = rockchip_clk_register_branch(list->name,
 510                                list->parent_names, list->num_parents,
 511                                ctx->reg_base, list->muxdiv_offset,
 512                                list->mux_shift,
 513                                list->mux_width, list->mux_flags,
 514                                list->div_offset, list->div_shift, list->div_width,
 515                                list->div_flags, list->div_table,
 516                                list->gate_offset, list->gate_shift,
 517                                list->gate_flags, flags, &ctx->lock);
 518                        break;
 519                case branch_mmc:
 520                        clk = rockchip_clk_register_mmc(
 521                                list->name,
 522                                list->parent_names, list->num_parents,
 523                                ctx->reg_base + list->muxdiv_offset,
 524                                list->div_shift
 525                        );
 526                        break;
 527                case branch_inverter:
 528                        clk = rockchip_clk_register_inverter(
 529                                list->name, list->parent_names,
 530                                list->num_parents,
 531                                ctx->reg_base + list->muxdiv_offset,
 532                                list->div_shift, list->div_flags, &ctx->lock);
 533                        break;
 534                case branch_factor:
 535                        clk = rockchip_clk_register_factor_branch(
 536                                list->name, list->parent_names,
 537                                list->num_parents, ctx->reg_base,
 538                                list->div_shift, list->div_width,
 539                                list->gate_offset, list->gate_shift,
 540                                list->gate_flags, flags, &ctx->lock);
 541                        break;
 542                case branch_ddrclk:
 543                        clk = rockchip_clk_register_ddrclk(
 544                                list->name, list->flags,
 545                                list->parent_names, list->num_parents,
 546                                list->muxdiv_offset, list->mux_shift,
 547                                list->mux_width, list->div_shift,
 548                                list->div_width, list->div_flags,
 549                                ctx->reg_base, &ctx->lock);
 550                        break;
 551                }
 552
 553                /* none of the cases above matched */
 554                if (!clk) {
 555                        pr_err("%s: unknown clock type %d\n",
 556                               __func__, list->branch_type);
 557                        continue;
 558                }
 559
 560                if (IS_ERR(clk)) {
 561                        pr_err("%s: failed to register clock %s: %ld\n",
 562                               __func__, list->name, PTR_ERR(clk));
 563                        continue;
 564                }
 565
 566                rockchip_clk_add_lookup(ctx, clk, list->id);
 567        }
 568}
 569
 570void __init rockchip_clk_register_armclk(struct rockchip_clk_provider *ctx,
 571                        unsigned int lookup_id,
 572                        const char *name, const char *const *parent_names,
 573                        u8 num_parents,
 574                        const struct rockchip_cpuclk_reg_data *reg_data,
 575                        const struct rockchip_cpuclk_rate_table *rates,
 576                        int nrates)
 577{
 578        struct clk *clk;
 579
 580        clk = rockchip_clk_register_cpuclk(name, parent_names, num_parents,
 581                                           reg_data, rates, nrates,
 582                                           ctx->reg_base, &ctx->lock);
 583        if (IS_ERR(clk)) {
 584                pr_err("%s: failed to register clock %s: %ld\n",
 585                       __func__, name, PTR_ERR(clk));
 586                return;
 587        }
 588
 589        rockchip_clk_add_lookup(ctx, clk, lookup_id);
 590}
 591
 592void __init rockchip_clk_protect_critical(const char *const clocks[],
 593                                          int nclocks)
 594{
 595        int i;
 596
 597        /* Protect the clocks that needs to stay on */
 598        for (i = 0; i < nclocks; i++) {
 599                struct clk *clk = __clk_lookup(clocks[i]);
 600
 601                if (clk)
 602                        clk_prepare_enable(clk);
 603        }
 604}
 605
 606static void __iomem *rst_base;
 607static unsigned int reg_restart;
 608static void (*cb_restart)(void);
 609static int rockchip_restart_notify(struct notifier_block *this,
 610                                   unsigned long mode, void *cmd)
 611{
 612        if (cb_restart)
 613                cb_restart();
 614
 615        writel(0xfdb9, rst_base + reg_restart);
 616        return NOTIFY_DONE;
 617}
 618
 619static struct notifier_block rockchip_restart_handler = {
 620        .notifier_call = rockchip_restart_notify,
 621        .priority = 128,
 622};
 623
 624void __init
 625rockchip_register_restart_notifier(struct rockchip_clk_provider *ctx,
 626                                               unsigned int reg,
 627                                               void (*cb)(void))
 628{
 629        int ret;
 630
 631        rst_base = ctx->reg_base;
 632        reg_restart = reg;
 633        cb_restart = cb;
 634        ret = register_restart_handler(&rockchip_restart_handler);
 635        if (ret)
 636                pr_err("%s: cannot register restart handler, %d\n",
 637                       __func__, ret);
 638}
 639