linux/drivers/clk/ti/clkctrl.c
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   1/*
   2 * OMAP clkctrl clock support
   3 *
   4 * Copyright (C) 2017 Texas Instruments, Inc.
   5 *
   6 * Tero Kristo <t-kristo@ti.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 *
  12 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  13 * kind, whether express or implied; without even the implied warranty
  14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 */
  17
  18#include <linux/clk-provider.h>
  19#include <linux/slab.h>
  20#include <linux/of.h>
  21#include <linux/of_address.h>
  22#include <linux/clk/ti.h>
  23#include <linux/delay.h>
  24#include "clock.h"
  25
  26#define NO_IDLEST                       0x1
  27
  28#define OMAP4_MODULEMODE_MASK           0x3
  29
  30#define MODULEMODE_HWCTRL               0x1
  31#define MODULEMODE_SWCTRL               0x2
  32
  33#define OMAP4_IDLEST_MASK               (0x3 << 16)
  34#define OMAP4_IDLEST_SHIFT              16
  35
  36#define CLKCTRL_IDLEST_FUNCTIONAL       0x0
  37#define CLKCTRL_IDLEST_INTERFACE_IDLE   0x2
  38#define CLKCTRL_IDLEST_DISABLED         0x3
  39
  40/* These timeouts are in us */
  41#define OMAP4_MAX_MODULE_READY_TIME     2000
  42#define OMAP4_MAX_MODULE_DISABLE_TIME   5000
  43
  44static bool _early_timeout = true;
  45
  46struct omap_clkctrl_provider {
  47        void __iomem *base;
  48        struct list_head clocks;
  49};
  50
  51struct omap_clkctrl_clk {
  52        struct clk_hw *clk;
  53        u16 reg_offset;
  54        int bit_offset;
  55        struct list_head node;
  56};
  57
  58union omap4_timeout {
  59        u32 cycles;
  60        ktime_t start;
  61};
  62
  63static const struct omap_clkctrl_data default_clkctrl_data[] __initconst = {
  64        { 0 },
  65};
  66
  67static u32 _omap4_idlest(u32 val)
  68{
  69        val &= OMAP4_IDLEST_MASK;
  70        val >>= OMAP4_IDLEST_SHIFT;
  71
  72        return val;
  73}
  74
  75static bool _omap4_is_idle(u32 val)
  76{
  77        val = _omap4_idlest(val);
  78
  79        return val == CLKCTRL_IDLEST_DISABLED;
  80}
  81
  82static bool _omap4_is_ready(u32 val)
  83{
  84        val = _omap4_idlest(val);
  85
  86        return val == CLKCTRL_IDLEST_FUNCTIONAL ||
  87               val == CLKCTRL_IDLEST_INTERFACE_IDLE;
  88}
  89
  90static bool _omap4_is_timeout(union omap4_timeout *time, u32 timeout)
  91{
  92        if (unlikely(_early_timeout)) {
  93                if (time->cycles++ < timeout) {
  94                        udelay(1);
  95                        return false;
  96                }
  97        } else {
  98                if (!ktime_to_ns(time->start)) {
  99                        time->start = ktime_get();
 100                        return false;
 101                }
 102
 103                if (ktime_us_delta(ktime_get(), time->start) < timeout) {
 104                        cpu_relax();
 105                        return false;
 106                }
 107        }
 108
 109        return true;
 110}
 111
 112static int __init _omap4_disable_early_timeout(void)
 113{
 114        _early_timeout = false;
 115
 116        return 0;
 117}
 118arch_initcall(_omap4_disable_early_timeout);
 119
 120static int _omap4_clkctrl_clk_enable(struct clk_hw *hw)
 121{
 122        struct clk_hw_omap *clk = to_clk_hw_omap(hw);
 123        u32 val;
 124        int ret;
 125        union omap4_timeout timeout = { 0 };
 126
 127        if (!clk->enable_bit)
 128                return 0;
 129
 130        if (clk->clkdm) {
 131                ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk);
 132                if (ret) {
 133                        WARN(1,
 134                             "%s: could not enable %s's clockdomain %s: %d\n",
 135                             __func__, clk_hw_get_name(hw),
 136                             clk->clkdm_name, ret);
 137                        return ret;
 138                }
 139        }
 140
 141        val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
 142
 143        val &= ~OMAP4_MODULEMODE_MASK;
 144        val |= clk->enable_bit;
 145
 146        ti_clk_ll_ops->clk_writel(val, &clk->enable_reg);
 147
 148        if (clk->flags & NO_IDLEST)
 149                return 0;
 150
 151        /* Wait until module is enabled */
 152        while (!_omap4_is_ready(ti_clk_ll_ops->clk_readl(&clk->enable_reg))) {
 153                if (_omap4_is_timeout(&timeout, OMAP4_MAX_MODULE_READY_TIME)) {
 154                        pr_err("%s: failed to enable\n", clk_hw_get_name(hw));
 155                        return -EBUSY;
 156                }
 157        }
 158
 159        return 0;
 160}
 161
 162static void _omap4_clkctrl_clk_disable(struct clk_hw *hw)
 163{
 164        struct clk_hw_omap *clk = to_clk_hw_omap(hw);
 165        u32 val;
 166        union omap4_timeout timeout = { 0 };
 167
 168        if (!clk->enable_bit)
 169                return;
 170
 171        val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
 172
 173        val &= ~OMAP4_MODULEMODE_MASK;
 174
 175        ti_clk_ll_ops->clk_writel(val, &clk->enable_reg);
 176
 177        if (clk->flags & NO_IDLEST)
 178                goto exit;
 179
 180        /* Wait until module is disabled */
 181        while (!_omap4_is_idle(ti_clk_ll_ops->clk_readl(&clk->enable_reg))) {
 182                if (_omap4_is_timeout(&timeout,
 183                                      OMAP4_MAX_MODULE_DISABLE_TIME)) {
 184                        pr_err("%s: failed to disable\n", clk_hw_get_name(hw));
 185                        break;
 186                }
 187        }
 188
 189exit:
 190        if (clk->clkdm)
 191                ti_clk_ll_ops->clkdm_clk_disable(clk->clkdm, hw->clk);
 192}
 193
 194static int _omap4_clkctrl_clk_is_enabled(struct clk_hw *hw)
 195{
 196        struct clk_hw_omap *clk = to_clk_hw_omap(hw);
 197        u32 val;
 198
 199        val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
 200
 201        if (val & clk->enable_bit)
 202                return 1;
 203
 204        return 0;
 205}
 206
 207static const struct clk_ops omap4_clkctrl_clk_ops = {
 208        .enable         = _omap4_clkctrl_clk_enable,
 209        .disable        = _omap4_clkctrl_clk_disable,
 210        .is_enabled     = _omap4_clkctrl_clk_is_enabled,
 211};
 212
 213static struct clk_hw *_ti_omap4_clkctrl_xlate(struct of_phandle_args *clkspec,
 214                                              void *data)
 215{
 216        struct omap_clkctrl_provider *provider = data;
 217        struct omap_clkctrl_clk *entry;
 218
 219        if (clkspec->args_count != 2)
 220                return ERR_PTR(-EINVAL);
 221
 222        pr_debug("%s: looking for %x:%x\n", __func__,
 223                 clkspec->args[0], clkspec->args[1]);
 224
 225        list_for_each_entry(entry, &provider->clocks, node) {
 226                if (entry->reg_offset == clkspec->args[0] &&
 227                    entry->bit_offset == clkspec->args[1])
 228                        break;
 229        }
 230
 231        if (!entry)
 232                return ERR_PTR(-EINVAL);
 233
 234        return entry->clk;
 235}
 236
 237static int __init
 238_ti_clkctrl_clk_register(struct omap_clkctrl_provider *provider,
 239                         struct device_node *node, struct clk_hw *clk_hw,
 240                         u16 offset, u8 bit, const char * const *parents,
 241                         int num_parents, const struct clk_ops *ops)
 242{
 243        struct clk_init_data init = { NULL };
 244        struct clk *clk;
 245        struct omap_clkctrl_clk *clkctrl_clk;
 246        int ret = 0;
 247
 248        init.name = kasprintf(GFP_KERNEL, "%s:%s:%04x:%d", node->parent->name,
 249                              node->name, offset, bit);
 250        clkctrl_clk = kzalloc(sizeof(*clkctrl_clk), GFP_KERNEL);
 251        if (!init.name || !clkctrl_clk) {
 252                ret = -ENOMEM;
 253                goto cleanup;
 254        }
 255
 256        clk_hw->init = &init;
 257        init.parent_names = parents;
 258        init.num_parents = num_parents;
 259        init.ops = ops;
 260        init.flags = CLK_IS_BASIC;
 261
 262        clk = ti_clk_register(NULL, clk_hw, init.name);
 263        if (IS_ERR_OR_NULL(clk)) {
 264                ret = -EINVAL;
 265                goto cleanup;
 266        }
 267
 268        clkctrl_clk->reg_offset = offset;
 269        clkctrl_clk->bit_offset = bit;
 270        clkctrl_clk->clk = clk_hw;
 271
 272        list_add(&clkctrl_clk->node, &provider->clocks);
 273
 274        return 0;
 275
 276cleanup:
 277        kfree(init.name);
 278        kfree(clkctrl_clk);
 279        return ret;
 280}
 281
 282static void __init
 283_ti_clkctrl_setup_gate(struct omap_clkctrl_provider *provider,
 284                       struct device_node *node, u16 offset,
 285                       const struct omap_clkctrl_bit_data *data,
 286                       void __iomem *reg)
 287{
 288        struct clk_hw_omap *clk_hw;
 289
 290        clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
 291        if (!clk_hw)
 292                return;
 293
 294        clk_hw->enable_bit = data->bit;
 295        clk_hw->enable_reg.ptr = reg;
 296
 297        if (_ti_clkctrl_clk_register(provider, node, &clk_hw->hw, offset,
 298                                     data->bit, data->parents, 1,
 299                                     &omap_gate_clk_ops))
 300                kfree(clk_hw);
 301}
 302
 303static void __init
 304_ti_clkctrl_setup_mux(struct omap_clkctrl_provider *provider,
 305                      struct device_node *node, u16 offset,
 306                      const struct omap_clkctrl_bit_data *data,
 307                      void __iomem *reg)
 308{
 309        struct clk_omap_mux *mux;
 310        int num_parents = 0;
 311        const char * const *pname;
 312
 313        mux = kzalloc(sizeof(*mux), GFP_KERNEL);
 314        if (!mux)
 315                return;
 316
 317        pname = data->parents;
 318        while (*pname) {
 319                num_parents++;
 320                pname++;
 321        }
 322
 323        mux->mask = num_parents;
 324        mux->mask = (1 << fls(mux->mask)) - 1;
 325
 326        mux->shift = data->bit;
 327        mux->reg.ptr = reg;
 328
 329        if (_ti_clkctrl_clk_register(provider, node, &mux->hw, offset,
 330                                     data->bit, data->parents, num_parents,
 331                                     &ti_clk_mux_ops))
 332                kfree(mux);
 333}
 334
 335static void __init
 336_ti_clkctrl_setup_div(struct omap_clkctrl_provider *provider,
 337                      struct device_node *node, u16 offset,
 338                      const struct omap_clkctrl_bit_data *data,
 339                      void __iomem *reg)
 340{
 341        struct clk_omap_divider *div;
 342        const struct omap_clkctrl_div_data *div_data = data->data;
 343
 344        div = kzalloc(sizeof(*div), GFP_KERNEL);
 345        if (!div)
 346                return;
 347
 348        div->reg.ptr = reg;
 349        div->shift = data->bit;
 350
 351        if (ti_clk_parse_divider_data((int *)div_data->dividers,
 352                                      div_data->max_div, 0, 0,
 353                                      &div->width, &div->table)) {
 354                pr_err("%s: Data parsing for %s:%04x:%d failed\n", __func__,
 355                       node->name, offset, data->bit);
 356                kfree(div);
 357                return;
 358        }
 359
 360        if (_ti_clkctrl_clk_register(provider, node, &div->hw, offset,
 361                                     data->bit, data->parents, 1,
 362                                     &ti_clk_divider_ops))
 363                kfree(div);
 364}
 365
 366static void __init
 367_ti_clkctrl_setup_subclks(struct omap_clkctrl_provider *provider,
 368                          struct device_node *node,
 369                          const struct omap_clkctrl_reg_data *data,
 370                          void __iomem *reg)
 371{
 372        const struct omap_clkctrl_bit_data *bits = data->bit_data;
 373
 374        if (!bits)
 375                return;
 376
 377        while (bits->bit) {
 378                switch (bits->type) {
 379                case TI_CLK_GATE:
 380                        _ti_clkctrl_setup_gate(provider, node, data->offset,
 381                                               bits, reg);
 382                        break;
 383
 384                case TI_CLK_DIVIDER:
 385                        _ti_clkctrl_setup_div(provider, node, data->offset,
 386                                              bits, reg);
 387                        break;
 388
 389                case TI_CLK_MUX:
 390                        _ti_clkctrl_setup_mux(provider, node, data->offset,
 391                                              bits, reg);
 392                        break;
 393
 394                default:
 395                        pr_err("%s: bad subclk type: %d\n", __func__,
 396                               bits->type);
 397                        return;
 398                }
 399                bits++;
 400        }
 401}
 402
 403static void __init _ti_omap4_clkctrl_setup(struct device_node *node)
 404{
 405        struct omap_clkctrl_provider *provider;
 406        const struct omap_clkctrl_data *data = default_clkctrl_data;
 407        const struct omap_clkctrl_reg_data *reg_data;
 408        struct clk_init_data init = { NULL };
 409        struct clk_hw_omap *hw;
 410        struct clk *clk;
 411        struct omap_clkctrl_clk *clkctrl_clk;
 412        const __be32 *addrp;
 413        u32 addr;
 414
 415        addrp = of_get_address(node, 0, NULL, NULL);
 416        addr = (u32)of_translate_address(node, addrp);
 417
 418#ifdef CONFIG_ARCH_OMAP4
 419        if (of_machine_is_compatible("ti,omap4"))
 420                data = omap4_clkctrl_data;
 421#endif
 422
 423        while (data->addr) {
 424                if (addr == data->addr)
 425                        break;
 426
 427                data++;
 428        }
 429
 430        if (!data->addr) {
 431                pr_err("%s not found from clkctrl data.\n", node->name);
 432                return;
 433        }
 434
 435        provider = kzalloc(sizeof(*provider), GFP_KERNEL);
 436        if (!provider)
 437                return;
 438
 439        provider->base = of_iomap(node, 0);
 440
 441        INIT_LIST_HEAD(&provider->clocks);
 442
 443        /* Generate clocks */
 444        reg_data = data->regs;
 445
 446        while (reg_data->parent) {
 447                hw = kzalloc(sizeof(*hw), GFP_KERNEL);
 448                if (!hw)
 449                        return;
 450
 451                hw->enable_reg.ptr = provider->base + reg_data->offset;
 452
 453                _ti_clkctrl_setup_subclks(provider, node, reg_data,
 454                                          hw->enable_reg.ptr);
 455
 456                if (reg_data->flags & CLKF_SW_SUP)
 457                        hw->enable_bit = MODULEMODE_SWCTRL;
 458                if (reg_data->flags & CLKF_HW_SUP)
 459                        hw->enable_bit = MODULEMODE_HWCTRL;
 460                if (reg_data->flags & CLKF_NO_IDLEST)
 461                        hw->flags |= NO_IDLEST;
 462
 463                init.parent_names = &reg_data->parent;
 464                init.num_parents = 1;
 465                init.flags = 0;
 466                init.name = kasprintf(GFP_KERNEL, "%s:%s:%04x:%d",
 467                                      node->parent->name, node->name,
 468                                      reg_data->offset, 0);
 469                clkctrl_clk = kzalloc(sizeof(*clkctrl_clk), GFP_KERNEL);
 470                if (!init.name || !clkctrl_clk)
 471                        goto cleanup;
 472
 473                init.ops = &omap4_clkctrl_clk_ops;
 474                hw->hw.init = &init;
 475
 476                clk = ti_clk_register(NULL, &hw->hw, init.name);
 477                if (IS_ERR_OR_NULL(clk))
 478                        goto cleanup;
 479
 480                clkctrl_clk->reg_offset = reg_data->offset;
 481                clkctrl_clk->clk = &hw->hw;
 482
 483                list_add(&clkctrl_clk->node, &provider->clocks);
 484
 485                reg_data++;
 486        }
 487
 488        of_clk_add_hw_provider(node, _ti_omap4_clkctrl_xlate, provider);
 489        return;
 490
 491cleanup:
 492        kfree(hw);
 493        kfree(init.name);
 494        kfree(clkctrl_clk);
 495}
 496CLK_OF_DECLARE(ti_omap4_clkctrl_clock, "ti,clkctrl",
 497               _ti_omap4_clkctrl_setup);
 498