drivers/clk/samsung/clk.c

   1 /*
   2  * Copyright (c) 2013 Samsung Electronics Co., Ltd.
   3  * Copyright (c) 2013 Linaro Ltd.
   4  * Author: Thomas Abraham <thomas.ab@samsung.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This file includes utility functions to register clocks to common
  11  * clock framework for Samsung platforms.
  12 */
  13
  14 #include <linux/of_address.h>
  15 #include <linux/syscore_ops.h>
  16
  17 #include "clk.h"
  18
  19 static LIST_HEAD(clock_reg_cache_list);
  20
  21 void samsung_clk_save(void __iomem *base,
  22                                     struct samsung_clk_reg_dump *rd,
  23                                     unsigned int num_regs)
  24 {
  25         for (; num_regs > 0; --num_regs, ++rd)
  26                 rd->value = readl(base + rd->offset);
  27 }
  28
  29 void samsung_clk_restore(void __iomem *base,
  30                                       const struct samsung_clk_reg_dump *rd,
  31                                       unsigned int num_regs)
  32 {
  33         for (; num_regs > 0; --num_regs, ++rd)
  34                 writel(rd->value, base + rd->offset);
  35 }
  36
  37 struct samsung_clk_reg_dump *samsung_clk_alloc_reg_dump(
  38                                                 const unsigned long *rdump,
  39                                                 unsigned long nr_rdump)
  40 {
  41         struct samsung_clk_reg_dump *rd;
  42         unsigned int i;
  43
  44         rd = kcalloc(nr_rdump, sizeof(*rd), GFP_KERNEL);
  45         if (!rd)
  46                 return NULL;
  47
  48         for (i = 0; i < nr_rdump; ++i)
  49                 rd[i].offset = rdump[i];
  50
  51         return rd;
  52 }
  53
  54 /* setup the essentials required to support clock lookup using ccf */
  55 struct samsung_clk_provider *__init samsung_clk_init(struct device_node *np,
  56                         void __iomem *base, unsigned long nr_clks)
  57 {
  58         struct samsung_clk_provider *ctx;
  59         struct clk **clk_table;
  60         int i;
  61
  62         ctx = kzalloc(sizeof(struct samsung_clk_provider), GFP_KERNEL);
  63         if (!ctx)
  64                 panic("could not allocate clock provider context.\n");
  65
  66         clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL);
  67         if (!clk_table)
  68                 panic("could not allocate clock lookup table\n");
  69
  70         for (i = 0; i < nr_clks; ++i)
  71                 clk_table[i] = ERR_PTR(-ENOENT);
  72
  73         ctx->reg_base = base;
  74         ctx->clk_data.clks = clk_table;
  75         ctx->clk_data.clk_num = nr_clks;
  76         spin_lock_init(&ctx->lock);
  77
  78         return ctx;
  79 }
  80
  81 void __init samsung_clk_of_add_provider(struct device_node *np,
  82                                 struct samsung_clk_provider *ctx)
  83 {
  84         if (np) {
  85                 if (of_clk_add_provider(np, of_clk_src_onecell_get,
  86                                         &ctx->clk_data))
  87                         panic("could not register clk provider\n");
  88         }
  89 }
  90
  91 /* add a clock instance to the clock lookup table used for dt based lookup */
  92 void samsung_clk_add_lookup(struct samsung_clk_provider *ctx, struct clk *clk,
  93                                 unsigned int id)
  94 {
  95         if (ctx->clk_data.clks && id)
  96                 ctx->clk_data.clks[id] = clk;
  97 }
  98
  99 /* register a list of aliases */
 100 void __init samsung_clk_register_alias(struct samsung_clk_provider *ctx,
 101                                 struct samsung_clock_alias *list,
 102                                 unsigned int nr_clk)
 103 {
 104         struct clk *clk;
 105         unsigned int idx, ret;
 106
 107         if (!ctx->clk_data.clks) {
 108                 pr_err("%s: clock table missing\n", __func__);
 109                 return;
 110         }
 111
 112         for (idx = 0; idx < nr_clk; idx++, list++) {
 113                 if (!list->id) {
 114                         pr_err("%s: clock id missing for index %d\n", __func__,
 115                                 idx);
 116                         continue;
 117                 }
 118
 119                 clk = ctx->clk_data.clks[list->id];
 120                 if (!clk) {
 121                         pr_err("%s: failed to find clock %d\n", __func__,
 122                                 list->id);
 123                         continue;
 124                 }
 125
 126                 ret = clk_register_clkdev(clk, list->alias, list->dev_name);
 127                 if (ret)
 128                         pr_err("%s: failed to register lookup %s\n",
 129                                         __func__, list->alias);
 130         }
 131 }
 132
 133 /* register a list of fixed clocks */
 134 void __init samsung_clk_register_fixed_rate(struct samsung_clk_provider *ctx,
 135                 struct samsung_fixed_rate_clock *list, unsigned int nr_clk)
 136 {
 137         struct clk *clk;
 138         unsigned int idx, ret;
 139
 140         for (idx = 0; idx < nr_clk; idx++, list++) {
 141                 clk = clk_register_fixed_rate(NULL, list->name,
 142                         list->parent_name, list->flags, list->fixed_rate);
 143                 if (IS_ERR(clk)) {
 144                         pr_err("%s: failed to register clock %s\n", __func__,
 145                                 list->name);
 146                         continue;
 147                 }
 148
 149                 samsung_clk_add_lookup(ctx, clk, list->id);
 150
 151                 /*
 152                  * Unconditionally add a clock lookup for the fixed rate clocks.
 153                  * There are not many of these on any of Samsung platforms.
 154                  */
 155                 ret = clk_register_clkdev(clk, list->name, NULL);
 156                 if (ret)
 157                         pr_err("%s: failed to register clock lookup for %s",
 158                                 __func__, list->name);
 159         }
 160 }
 161
 162 /* register a list of fixed factor clocks */
 163 void __init samsung_clk_register_fixed_factor(struct samsung_clk_provider *ctx,
 164                 struct samsung_fixed_factor_clock *list, unsigned int nr_clk)
 165 {
 166         struct clk *clk;
 167         unsigned int idx;
 168
 169         for (idx = 0; idx < nr_clk; idx++, list++) {
 170                 clk = clk_register_fixed_factor(NULL, list->name,
 171                         list->parent_name, list->flags, list->mult, list->div);
 172                 if (IS_ERR(clk)) {
 173                         pr_err("%s: failed to register clock %s\n", __func__,
 174                                 list->name);
 175                         continue;
 176                 }
 177
 178                 samsung_clk_add_lookup(ctx, clk, list->id);
 179         }
 180 }
 181
 182 /* register a list of mux clocks */
 183 void __init samsung_clk_register_mux(struct samsung_clk_provider *ctx,
 184                                 struct samsung_mux_clock *list,
 185                                 unsigned int nr_clk)
 186 {
 187         struct clk *clk;
 188         unsigned int idx, ret;
 189
 190         for (idx = 0; idx < nr_clk; idx++, list++) {
 191                 clk = clk_register_mux(NULL, list->name, list->parent_names,
 192                         list->num_parents, list->flags,
 193                         ctx->reg_base + list->offset,
 194                         list->shift, list->width, list->mux_flags, &ctx->lock);
 195                 if (IS_ERR(clk)) {
 196                         pr_err("%s: failed to register clock %s\n", __func__,
 197                                 list->name);
 198                         continue;
 199                 }
 200
 201                 samsung_clk_add_lookup(ctx, clk, list->id);
 202
 203                 /* register a clock lookup only if a clock alias is specified */
 204                 if (list->alias) {
 205                         ret = clk_register_clkdev(clk, list->alias,
 206                                                 list->dev_name);
 207                         if (ret)
 208                                 pr_err("%s: failed to register lookup %s\n",
 209                                                 __func__, list->alias);
 210                 }
 211         }
 212 }
 213
 214 /* register a list of div clocks */
 215 void __init samsung_clk_register_div(struct samsung_clk_provider *ctx,
 216                                 struct samsung_div_clock *list,
 217                                 unsigned int nr_clk)
 218 {
 219         struct clk *clk;
 220         unsigned int idx, ret;
 221
 222         for (idx = 0; idx < nr_clk; idx++, list++) {
 223                 if (list->table)
 224                         clk = clk_register_divider_table(NULL, list->name,
 225                                 list->parent_name, list->flags,
 226                                 ctx->reg_base + list->offset,
 227                                 list->shift, list->width, list->div_flags,
 228                                 list->table, &ctx->lock);
 229                 else
 230                         clk = clk_register_divider(NULL, list->name,
 231                                 list->parent_name, list->flags,
 232                                 ctx->reg_base + list->offset, list->shift,
 233                                 list->width, list->div_flags, &ctx->lock);
 234                 if (IS_ERR(clk)) {
 235                         pr_err("%s: failed to register clock %s\n", __func__,
 236                                 list->name);
 237                         continue;
 238                 }
 239
 240                 samsung_clk_add_lookup(ctx, clk, list->id);
 241
 242                 /* register a clock lookup only if a clock alias is specified */
 243                 if (list->alias) {
 244                         ret = clk_register_clkdev(clk, list->alias,
 245                                                 list->dev_name);
 246                         if (ret)
 247                                 pr_err("%s: failed to register lookup %s\n",
 248                                                 __func__, list->alias);
 249                 }
 250         }
 251 }
 252
 253 /* register a list of gate clocks */
 254 void __init samsung_clk_register_gate(struct samsung_clk_provider *ctx,
 255                                 struct samsung_gate_clock *list,
 256                                 unsigned int nr_clk)
 257 {
 258         struct clk *clk;
 259         unsigned int idx, ret;
 260
 261         for (idx = 0; idx < nr_clk; idx++, list++) {
 262                 clk = clk_register_gate(NULL, list->name, list->parent_name,
 263                                 list->flags, ctx->reg_base + list->offset,
 264                                 list->bit_idx, list->gate_flags, &ctx->lock);
 265                 if (IS_ERR(clk)) {
 266                         pr_err("%s: failed to register clock %s\n", __func__,
 267                                 list->name);
 268                         continue;
 269                 }
 270
 271                 /* register a clock lookup only if a clock alias is specified */
 272                 if (list->alias) {
 273                         ret = clk_register_clkdev(clk, list->alias,
 274                                                         list->dev_name);
 275                         if (ret)
 276                                 pr_err("%s: failed to register lookup %s\n",
 277                                         __func__, list->alias);
 278                 }
 279
 280                 samsung_clk_add_lookup(ctx, clk, list->id);
 281         }
 282 }
 283
 284 /*
 285  * obtain the clock speed of all external fixed clock sources from device
 286  * tree and register it
 287  */
 288 void __init samsung_clk_of_register_fixed_ext(struct samsung_clk_provider *ctx,
 289                         struct samsung_fixed_rate_clock *fixed_rate_clk,
 290                         unsigned int nr_fixed_rate_clk,
 291                         const struct of_device_id *clk_matches)
 292 {
 293         const struct of_device_id *match;
 294         struct device_node *clk_np;
 295         u32 freq;
 296
 297         for_each_matching_node_and_match(clk_np, clk_matches, &match) {
 298                 if (of_property_read_u32(clk_np, "clock-frequency", &freq))
 299                         continue;
 300                 fixed_rate_clk[(unsigned long)match->data].fixed_rate = freq;
 301         }
 302         samsung_clk_register_fixed_rate(ctx, fixed_rate_clk, nr_fixed_rate_clk);
 303 }
 304
 305 /* utility function to get the rate of a specified clock */
 306 unsigned long _get_rate(const char *clk_name)
 307 {
 308         struct clk *clk;
 309
 310         clk = __clk_lookup(clk_name);
 311         if (!clk) {
 312                 pr_err("%s: could not find clock %s\n", __func__, clk_name);
 313                 return 0;
 314         }
 315
 316         return clk_get_rate(clk);
 317 }
 318
 319 #ifdef CONFIG_PM_SLEEP
 320 static int samsung_clk_suspend(void)
 321 {
 322         struct samsung_clock_reg_cache *reg_cache;
 323
 324         list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
 325                 samsung_clk_save(reg_cache->reg_base, reg_cache->rdump,
 326                                 reg_cache->rd_num);
 327         return 0;
 328 }
 329
 330 static void samsung_clk_resume(void)
 331 {
 332         struct samsung_clock_reg_cache *reg_cache;
 333
 334         list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
 335                 samsung_clk_restore(reg_cache->reg_base, reg_cache->rdump,
 336                                 reg_cache->rd_num);
 337 }
 338
 339 static struct syscore_ops samsung_clk_syscore_ops = {
 340         .suspend = samsung_clk_suspend,
 341         .resume = samsung_clk_resume,
 342 };
 343
 344 static void samsung_clk_sleep_init(void __iomem *reg_base,
 345                 const unsigned long *rdump,
 346                 unsigned long nr_rdump)
 347 {
 348         struct samsung_clock_reg_cache *reg_cache;
 349
 350         reg_cache = kzalloc(sizeof(struct samsung_clock_reg_cache),
 351                         GFP_KERNEL);
 352         if (!reg_cache)
 353                 panic("could not allocate register reg_cache.\n");
 354         reg_cache->rdump = samsung_clk_alloc_reg_dump(rdump, nr_rdump);
 355
 356         if (!reg_cache->rdump)
 357                 panic("could not allocate register dump storage.\n");
 358
 359         if (list_empty(&clock_reg_cache_list))
 360                 register_syscore_ops(&samsung_clk_syscore_ops);
 361
 362         reg_cache->reg_base = reg_base;
 363         reg_cache->rd_num = nr_rdump;
 364         list_add_tail(&reg_cache->node, &clock_reg_cache_list);
 365 }
 366
 367 #else
 368 static void samsung_clk_sleep_init(void __iomem *reg_base,
 369                 const unsigned long *rdump,
 370                 unsigned long nr_rdump) {}
 371 #endif
 372
 373 /*
 374  * Common function which registers plls, muxes, dividers and gates
 375  * for each CMU. It also add CMU register list to register cache.
 376  */
 377 struct samsung_clk_provider * __init samsung_cmu_register_one(
 378                         struct device_node *np,
 379                         struct samsung_cmu_info *cmu)
 380 {
 381         void __iomem *reg_base;
 382         struct samsung_clk_provider *ctx;
 383
 384         reg_base = of_iomap(np, 0);
 385         if (!reg_base) {
 386                 panic("%s: failed to map registers\n", __func__);
 387                 return NULL;
 388         }
 389
 390         ctx = samsung_clk_init(np, reg_base, cmu->nr_clk_ids);
 391         if (!ctx) {
 392                 panic("%s: unable to alllocate ctx\n", __func__);
 393                 return ctx;
 394         }
 395
 396         if (cmu->pll_clks)
 397                 samsung_clk_register_pll(ctx, cmu->pll_clks, cmu->nr_pll_clks,
 398                         reg_base);
 399         if (cmu->mux_clks)
 400                 samsung_clk_register_mux(ctx, cmu->mux_clks,
 401                         cmu->nr_mux_clks);
 402         if (cmu->div_clks)
 403                 samsung_clk_register_div(ctx, cmu->div_clks, cmu->nr_div_clks);
 404         if (cmu->gate_clks)
 405                 samsung_clk_register_gate(ctx, cmu->gate_clks,
 406                         cmu->nr_gate_clks);
 407         if (cmu->fixed_clks)
 408                 samsung_clk_register_fixed_rate(ctx, cmu->fixed_clks,
 409                         cmu->nr_fixed_clks);
 410         if (cmu->fixed_factor_clks)
 411                 samsung_clk_register_fixed_factor(ctx, cmu->fixed_factor_clks,
 412                         cmu->nr_fixed_factor_clks);
 413         if (cmu->clk_regs)
 414                 samsung_clk_sleep_init(reg_base, cmu->clk_regs,
 415                         cmu->nr_clk_regs);
 416
 417         samsung_clk_of_add_provider(np, ctx);
 418
 419         return ctx;
 420 }