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