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                                 const 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                 const struct samsung_fixed_rate_clock *list,
 136                 unsigned int nr_clk)
 137 {
 138         struct clk *clk;
 139         unsigned int idx, ret;
 140
 141         for (idx = 0; idx < nr_clk; idx++, list++) {
 142                 clk = clk_register_fixed_rate(NULL, list->name,
 143                         list->parent_name, list->flags, list->fixed_rate);
 144                 if (IS_ERR(clk)) {
 145                         pr_err("%s: failed to register clock %s\n", __func__,
 146                                 list->name);
 147                         continue;
 148                 }
 149
 150                 samsung_clk_add_lookup(ctx, clk, list->id);
 151
 152                 /*
 153                  * Unconditionally add a clock lookup for the fixed rate clocks.
 154                  * There are not many of these on any of Samsung platforms.
 155                  */
 156                 ret = clk_register_clkdev(clk, list->name, NULL);
 157                 if (ret)
 158                         pr_err("%s: failed to register clock lookup for %s",
 159                                 __func__, list->name);
 160         }
 161 }
 162
 163 /* register a list of fixed factor clocks */
 164 void __init samsung_clk_register_fixed_factor(struct samsung_clk_provider *ctx,
 165                 const struct samsung_fixed_factor_clock *list, unsigned int nr_clk)
 166 {
 167         struct clk *clk;
 168         unsigned int idx;
 169
 170         for (idx = 0; idx < nr_clk; idx++, list++) {
 171                 clk = clk_register_fixed_factor(NULL, list->name,
 172                         list->parent_name, list->flags, list->mult, list->div);
 173                 if (IS_ERR(clk)) {
 174                         pr_err("%s: failed to register clock %s\n", __func__,
 175                                 list->name);
 176                         continue;
 177                 }
 178
 179                 samsung_clk_add_lookup(ctx, clk, list->id);
 180         }
 181 }
 182
 183 /* register a list of mux clocks */
 184 void __init samsung_clk_register_mux(struct samsung_clk_provider *ctx,
 185                                 const struct samsung_mux_clock *list,
 186                                 unsigned int nr_clk)
 187 {
 188         struct clk *clk;
 189         unsigned int idx, ret;
 190
 191         for (idx = 0; idx < nr_clk; idx++, list++) {
 192                 clk = clk_register_mux(NULL, list->name, list->parent_names,
 193                         list->num_parents, list->flags,
 194                         ctx->reg_base + list->offset,
 195                         list->shift, list->width, list->mux_flags, &ctx->lock);
 196                 if (IS_ERR(clk)) {
 197                         pr_err("%s: failed to register clock %s\n", __func__,
 198                                 list->name);
 199                         continue;
 200                 }
 201
 202                 samsung_clk_add_lookup(ctx, clk, list->id);
 203
 204                 /* register a clock lookup only if a clock alias is specified */
 205                 if (list->alias) {
 206                         ret = clk_register_clkdev(clk, list->alias,
 207                                                 list->dev_name);
 208                         if (ret)
 209                                 pr_err("%s: failed to register lookup %s\n",
 210                                                 __func__, list->alias);
 211                 }
 212         }
 213 }
 214
 215 /* register a list of div clocks */
 216 void __init samsung_clk_register_div(struct samsung_clk_provider *ctx,
 217                                 const struct samsung_div_clock *list,
 218                                 unsigned int nr_clk)
 219 {
 220         struct clk *clk;
 221         unsigned int idx, ret;
 222
 223         for (idx = 0; idx < nr_clk; idx++, list++) {
 224                 if (list->table)
 225                         clk = clk_register_divider_table(NULL, list->name,
 226                                 list->parent_name, list->flags,
 227                                 ctx->reg_base + list->offset,
 228                                 list->shift, list->width, list->div_flags,
 229                                 list->table, &ctx->lock);
 230                 else
 231                         clk = clk_register_divider(NULL, list->name,
 232                                 list->parent_name, list->flags,
 233                                 ctx->reg_base + list->offset, list->shift,
 234                                 list->width, list->div_flags, &ctx->lock);
 235                 if (IS_ERR(clk)) {
 236                         pr_err("%s: failed to register clock %s\n", __func__,
 237                                 list->name);
 238                         continue;
 239                 }
 240
 241                 samsung_clk_add_lookup(ctx, clk, list->id);
 242
 243                 /* register a clock lookup only if a clock alias is specified */
 244                 if (list->alias) {
 245                         ret = clk_register_clkdev(clk, list->alias,
 246                                                 list->dev_name);
 247                         if (ret)
 248                                 pr_err("%s: failed to register lookup %s\n",
 249                                                 __func__, list->alias);
 250                 }
 251         }
 252 }
 253
 254 /* register a list of gate clocks */
 255 void __init samsung_clk_register_gate(struct samsung_clk_provider *ctx,
 256                                 const struct samsung_gate_clock *list,
 257                                 unsigned int nr_clk)
 258 {
 259         struct clk *clk;
 260         unsigned int idx, ret;
 261
 262         for (idx = 0; idx < nr_clk; idx++, list++) {
 263                 clk = clk_register_gate(NULL, list->name, list->parent_name,
 264                                 list->flags, ctx->reg_base + list->offset,
 265                                 list->bit_idx, list->gate_flags, &ctx->lock);
 266                 if (IS_ERR(clk)) {
 267                         pr_err("%s: failed to register clock %s\n", __func__,
 268                                 list->name);
 269                         continue;
 270                 }
 271
 272                 /* register a clock lookup only if a clock alias is specified */
 273                 if (list->alias) {
 274                         ret = clk_register_clkdev(clk, list->alias,
 275                                                         list->dev_name);
 276                         if (ret)
 277                                 pr_err("%s: failed to register lookup %s\n",
 278                                         __func__, list->alias);
 279                 }
 280
 281                 samsung_clk_add_lookup(ctx, clk, list->id);
 282         }
 283 }
 284
 285 /*
 286  * obtain the clock speed of all external fixed clock sources from device
 287  * tree and register it
 288  */
 289 void __init samsung_clk_of_register_fixed_ext(struct samsung_clk_provider *ctx,
 290                         struct samsung_fixed_rate_clock *fixed_rate_clk,
 291                         unsigned int nr_fixed_rate_clk,
 292                         const struct of_device_id *clk_matches)
 293 {
 294         const struct of_device_id *match;
 295         struct device_node *clk_np;
 296         u32 freq;
 297
 298         for_each_matching_node_and_match(clk_np, clk_matches, &match) {
 299                 if (of_property_read_u32(clk_np, "clock-frequency", &freq))
 300                         continue;
 301                 fixed_rate_clk[(unsigned long)match->data].fixed_rate = freq;
 302         }
 303         samsung_clk_register_fixed_rate(ctx, fixed_rate_clk, nr_fixed_rate_clk);
 304 }
 305
 306 /* utility function to get the rate of a specified clock */
 307 unsigned long _get_rate(const char *clk_name)
 308 {
 309         struct clk *clk;
 310
 311         clk = __clk_lookup(clk_name);
 312         if (!clk) {
 313                 pr_err("%s: could not find clock %s\n", __func__, clk_name);
 314                 return 0;
 315         }
 316
 317         return clk_get_rate(clk);
 318 }
 319
 320 #ifdef CONFIG_PM_SLEEP
 321 static int samsung_clk_suspend(void)
 322 {
 323         struct samsung_clock_reg_cache *reg_cache;
 324
 325         list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
 326                 samsung_clk_save(reg_cache->reg_base, reg_cache->rdump,
 327                                 reg_cache->rd_num);
 328         return 0;
 329 }
 330
 331 static void samsung_clk_resume(void)
 332 {
 333         struct samsung_clock_reg_cache *reg_cache;
 334
 335         list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
 336                 samsung_clk_restore(reg_cache->reg_base, reg_cache->rdump,
 337                                 reg_cache->rd_num);
 338 }
 339
 340 static struct syscore_ops samsung_clk_syscore_ops = {
 341         .suspend = samsung_clk_suspend,
 342         .resume = samsung_clk_resume,
 343 };
 344
 345 static void samsung_clk_sleep_init(void __iomem *reg_base,
 346                 const unsigned long *rdump,
 347                 unsigned long nr_rdump)
 348 {
 349         struct samsung_clock_reg_cache *reg_cache;
 350
 351         reg_cache = kzalloc(sizeof(struct samsung_clock_reg_cache),
 352                         GFP_KERNEL);
 353         if (!reg_cache)
 354                 panic("could not allocate register reg_cache.\n");
 355         reg_cache->rdump = samsung_clk_alloc_reg_dump(rdump, nr_rdump);
 356
 357         if (!reg_cache->rdump)
 358                 panic("could not allocate register dump storage.\n");
 359
 360         if (list_empty(&clock_reg_cache_list))
 361                 register_syscore_ops(&samsung_clk_syscore_ops);
 362
 363         reg_cache->reg_base = reg_base;
 364         reg_cache->rd_num = nr_rdump;
 365         list_add_tail(&reg_cache->node, &clock_reg_cache_list);
 366 }
 367
 368 #else
 369 static void samsung_clk_sleep_init(void __iomem *reg_base,
 370                 const unsigned long *rdump,
 371                 unsigned long nr_rdump) {}
 372 #endif
 373
 374 /*
 375  * Common function which registers plls, muxes, dividers and gates
 376  * for each CMU. It also add CMU register list to register cache.
 377  */
 378 struct samsung_clk_provider * __init samsung_cmu_register_one(
 379                         struct device_node *np,
 380                         struct samsung_cmu_info *cmu)
 381 {
 382         void __iomem *reg_base;
 383         struct samsung_clk_provider *ctx;
 384
 385         reg_base = of_iomap(np, 0);
 386         if (!reg_base) {
 387                 panic("%s: failed to map registers\n", __func__);
 388                 return NULL;
 389         }
 390
 391         ctx = samsung_clk_init(np, reg_base, cmu->nr_clk_ids);
 392         if (!ctx) {
 393                 panic("%s: unable to allocate ctx\n", __func__);
 394                 return ctx;
 395         }
 396
 397         if (cmu->pll_clks)
 398                 samsung_clk_register_pll(ctx, cmu->pll_clks, cmu->nr_pll_clks,
 399                         reg_base);
 400         if (cmu->mux_clks)
 401                 samsung_clk_register_mux(ctx, cmu->mux_clks,
 402                         cmu->nr_mux_clks);
 403         if (cmu->div_clks)
 404                 samsung_clk_register_div(ctx, cmu->div_clks, cmu->nr_div_clks);
 405         if (cmu->gate_clks)
 406                 samsung_clk_register_gate(ctx, cmu->gate_clks,
 407                         cmu->nr_gate_clks);
 408         if (cmu->fixed_clks)
 409                 samsung_clk_register_fixed_rate(ctx, cmu->fixed_clks,
 410                         cmu->nr_fixed_clks);
 411         if (cmu->fixed_factor_clks)
 412                 samsung_clk_register_fixed_factor(ctx, cmu->fixed_factor_clks,
 413                         cmu->nr_fixed_factor_clks);
 414         if (cmu->clk_regs)
 415                 samsung_clk_sleep_init(reg_base, cmu->clk_regs,
 416                         cmu->nr_clk_regs);
 417
 418         samsung_clk_of_add_provider(np, ctx);
 419
 420         return ctx;
 421 }