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/syscore_ops.h>
  15 #include "clk.h"
  16
  17 static DEFINE_SPINLOCK(lock);
  18 static struct clk **clk_table;
  19 static void __iomem *reg_base;
  20 #ifdef CONFIG_OF
  21 static struct clk_onecell_data clk_data;
  22 #endif
  23
  24 #ifdef CONFIG_PM_SLEEP
  25 static struct samsung_clk_reg_dump *reg_dump;
  26 static unsigned long nr_reg_dump;
  27
  28 static int samsung_clk_suspend(void)
  29 {
  30         struct samsung_clk_reg_dump *rd = reg_dump;
  31         unsigned long i;
  32
  33         for (i = 0; i < nr_reg_dump; i++, rd++)
  34                 rd->value = __raw_readl(reg_base + rd->offset);
  35
  36         return 0;
  37 }
  38
  39 static void samsung_clk_resume(void)
  40 {
  41         struct samsung_clk_reg_dump *rd = reg_dump;
  42         unsigned long i;
  43
  44         for (i = 0; i < nr_reg_dump; i++, rd++)
  45                 __raw_writel(rd->value, reg_base + rd->offset);
  46 }
  47
  48 static struct syscore_ops samsung_clk_syscore_ops = {
  49         .suspend        = samsung_clk_suspend,
  50         .resume         = samsung_clk_resume,
  51 };
  52 #endif /* CONFIG_PM_SLEEP */
  53
  54 /* setup the essentials required to support clock lookup using ccf */
  55 void __init samsung_clk_init(struct device_node *np, void __iomem *base,
  56                 unsigned long nr_clks, unsigned long *rdump,
  57                 unsigned long nr_rdump, unsigned long *soc_rdump,
  58                 unsigned long nr_soc_rdump)
  59 {
  60         reg_base = base;
  61
  62 #ifdef CONFIG_PM_SLEEP
  63         if (rdump && nr_rdump) {
  64                 unsigned int idx;
  65                 reg_dump = kzalloc(sizeof(struct samsung_clk_reg_dump)
  66                                 * (nr_rdump + nr_soc_rdump), GFP_KERNEL);
  67                 if (!reg_dump) {
  68                         pr_err("%s: memory alloc for register dump failed\n",
  69                                         __func__);
  70                         return;
  71                 }
  72
  73                 for (idx = 0; idx < nr_rdump; idx++)
  74                         reg_dump[idx].offset = rdump[idx];
  75                 for (idx = 0; idx < nr_soc_rdump; idx++)
  76                         reg_dump[nr_rdump + idx].offset = soc_rdump[idx];
  77                 nr_reg_dump = nr_rdump + nr_soc_rdump;
  78                 register_syscore_ops(&samsung_clk_syscore_ops);
  79         }
  80 #endif
  81
  82         clk_table = kzalloc(sizeof(struct clk *) * nr_clks, GFP_KERNEL);
  83         if (!clk_table)
  84                 panic("could not allocate clock lookup table\n");
  85
  86         if (!np)
  87                 return;
  88
  89 #ifdef CONFIG_OF
  90         clk_data.clks = clk_table;
  91         clk_data.clk_num = nr_clks;
  92         of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
  93 #endif
  94 }
  95
  96 /* add a clock instance to the clock lookup table used for dt based lookup */
  97 void samsung_clk_add_lookup(struct clk *clk, unsigned int id)
  98 {
  99         if (clk_table && id)
 100                 clk_table[id] = clk;
 101 }
 102
 103 /* register a list of aliases */
 104 void __init samsung_clk_register_alias(struct samsung_clock_alias *list,
 105                                         unsigned int nr_clk)
 106 {
 107         struct clk *clk;
 108         unsigned int idx, ret;
 109
 110         if (!clk_table) {
 111                 pr_err("%s: clock table missing\n", __func__);
 112                 return;
 113         }
 114
 115         for (idx = 0; idx < nr_clk; idx++, list++) {
 116                 if (!list->id) {
 117                         pr_err("%s: clock id missing for index %d\n", __func__,
 118                                 idx);
 119                         continue;
 120                 }
 121
 122                 clk = clk_table[list->id];
 123                 if (!clk) {
 124                         pr_err("%s: failed to find clock %d\n", __func__,
 125                                 list->id);
 126                         continue;
 127                 }
 128
 129                 ret = clk_register_clkdev(clk, list->alias, list->dev_name);
 130                 if (ret)
 131                         pr_err("%s: failed to register lookup %s\n",
 132                                         __func__, list->alias);
 133         }
 134 }
 135
 136 /* register a list of fixed clocks */
 137 void __init samsung_clk_register_fixed_rate(
 138                 struct samsung_fixed_rate_clock *list, unsigned int nr_clk)
 139 {
 140         struct clk *clk;
 141         unsigned int idx, ret;
 142
 143         for (idx = 0; idx < nr_clk; idx++, list++) {
 144                 clk = clk_register_fixed_rate(NULL, list->name,
 145                         list->parent_name, list->flags, list->fixed_rate);
 146                 if (IS_ERR(clk)) {
 147                         pr_err("%s: failed to register clock %s\n", __func__,
 148                                 list->name);
 149                         continue;
 150                 }
 151
 152                 samsung_clk_add_lookup(clk, list->id);
 153
 154                 /*
 155                  * Unconditionally add a clock lookup for the fixed rate clocks.
 156                  * There are not many of these on any of Samsung platforms.
 157                  */
 158                 ret = clk_register_clkdev(clk, list->name, NULL);
 159                 if (ret)
 160                         pr_err("%s: failed to register clock lookup for %s",
 161                                 __func__, list->name);
 162         }
 163 }
 164
 165 /* register a list of fixed factor clocks */
 166 void __init samsung_clk_register_fixed_factor(
 167                 struct samsung_fixed_factor_clock *list, unsigned int nr_clk)
 168 {
 169         struct clk *clk;
 170         unsigned int idx;
 171
 172         for (idx = 0; idx < nr_clk; idx++, list++) {
 173                 clk = clk_register_fixed_factor(NULL, list->name,
 174                         list->parent_name, list->flags, list->mult, list->div);
 175                 if (IS_ERR(clk)) {
 176                         pr_err("%s: failed to register clock %s\n", __func__,
 177                                 list->name);
 178                         continue;
 179                 }
 180
 181                 samsung_clk_add_lookup(clk, list->id);
 182         }
 183 }
 184
 185 /* register a list of mux clocks */
 186 void __init samsung_clk_register_mux(struct samsung_mux_clock *list,
 187                                         unsigned int nr_clk)
 188 {
 189         struct clk *clk;
 190         unsigned int idx, ret;
 191
 192         for (idx = 0; idx < nr_clk; idx++, list++) {
 193                 clk = clk_register_mux(NULL, list->name, list->parent_names,
 194                         list->num_parents, list->flags, reg_base + list->offset,
 195                         list->shift, list->width, list->mux_flags, &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(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_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                                         reg_base + list->offset, list->shift,
 227                                         list->width, list->div_flags,
 228                                         list->table, &lock);
 229                 else
 230                         clk = clk_register_divider(NULL, list->name,
 231                                         list->parent_name, list->flags,
 232                                         reg_base + list->offset, list->shift,
 233                                         list->width, list->div_flags, &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(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_gate_clock *list,
 255                                                 unsigned int nr_clk)
 256 {
 257         struct clk *clk;
 258         unsigned int idx, ret;
 259
 260         for (idx = 0; idx < nr_clk; idx++, list++) {
 261                 clk = clk_register_gate(NULL, list->name, list->parent_name,
 262                                 list->flags, reg_base + list->offset,
 263                                 list->bit_idx, list->gate_flags, &lock);
 264                 if (IS_ERR(clk)) {
 265                         pr_err("%s: failed to register clock %s\n", __func__,
 266                                 list->name);
 267                         continue;
 268                 }
 269
 270                 /* register a clock lookup only if a clock alias is specified */
 271                 if (list->alias) {
 272                         ret = clk_register_clkdev(clk, list->alias,
 273                                                         list->dev_name);
 274                         if (ret)
 275                                 pr_err("%s: failed to register lookup %s\n",
 276                                         __func__, list->alias);
 277                 }
 278
 279                 samsung_clk_add_lookup(clk, list->id);
 280         }
 281 }
 282
 283 /*
 284  * obtain the clock speed of all external fixed clock sources from device
 285  * tree and register it
 286  */
 287 #ifdef CONFIG_OF
 288 void __init samsung_clk_of_register_fixed_ext(
 289                         struct samsung_fixed_rate_clock *fixed_rate_clk,
 290                         unsigned int nr_fixed_rate_clk,
 291                         struct of_device_id *clk_matches)
 292 {
 293         const struct of_device_id *match;
 294         struct device_node *np;
 295         u32 freq;
 296
 297         for_each_matching_node_and_match(np, clk_matches, &match) {
 298                 if (of_property_read_u32(np, "clock-frequency", &freq))
 299                         continue;
 300                 fixed_rate_clk[(u32)match->data].fixed_rate = freq;
 301         }
 302         samsung_clk_register_fixed_rate(fixed_rate_clk, nr_fixed_rate_clk);
 303 }
 304 #endif
 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         unsigned long rate;
 311
 312         clk = clk_get(NULL, clk_name);
 313         if (IS_ERR(clk)) {
 314                 pr_err("%s: could not find clock %s\n", __func__, clk_name);
 315                 return 0;
 316         }
 317         rate = clk_get_rate(clk);
 318         clk_put(clk);
 319         return rate;
 320 }