drivers/sh/clk/cpg.c

   1 /*
   2  * Helper routines for SuperH Clock Pulse Generator blocks (CPG).
   3  *
   4  *  Copyright (C) 2010  Magnus Damm
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10 #include <linux/clk.h>
  11 #include <linux/compiler.h>
  12 #include <linux/slab.h>
  13 #include <linux/io.h>
  14 #include <linux/sh_clk.h>
  15
  16 static int sh_clk_mstp32_enable(struct clk *clk)
  17 {
  18         iowrite32(ioread32(clk->mapped_reg) & ~(1 << clk->enable_bit),
  19                   clk->mapped_reg);
  20         return 0;
  21 }
  22
  23 static void sh_clk_mstp32_disable(struct clk *clk)
  24 {
  25         iowrite32(ioread32(clk->mapped_reg) | (1 << clk->enable_bit),
  26                   clk->mapped_reg);
  27 }
  28
  29 static struct clk_ops sh_clk_mstp32_clk_ops = {
  30         .enable         = sh_clk_mstp32_enable,
  31         .disable        = sh_clk_mstp32_disable,
  32         .recalc         = followparent_recalc,
  33 };
  34
  35 int __init sh_clk_mstp32_register(struct clk *clks, int nr)
  36 {
  37         struct clk *clkp;
  38         int ret = 0;
  39         int k;
  40
  41         for (k = 0; !ret && (k < nr); k++) {
  42                 clkp = clks + k;
  43                 clkp->ops = &sh_clk_mstp32_clk_ops;
  44                 ret |= clk_register(clkp);
  45         }
  46
  47         return ret;
  48 }
  49
  50 static long sh_clk_div_round_rate(struct clk *clk, unsigned long rate)
  51 {
  52         return clk_rate_table_round(clk, clk->freq_table, rate);
  53 }
  54
  55 static int sh_clk_div6_divisors[64] = {
  56         1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
  57         17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32,
  58         33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,
  59         49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64
  60 };
  61
  62 static struct clk_div_mult_table sh_clk_div6_table = {
  63         .divisors = sh_clk_div6_divisors,
  64         .nr_divisors = ARRAY_SIZE(sh_clk_div6_divisors),
  65 };
  66
  67 static unsigned long sh_clk_div6_recalc(struct clk *clk)
  68 {
  69         struct clk_div_mult_table *table = &sh_clk_div6_table;
  70         unsigned int idx;
  71
  72         clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
  73                              table, NULL);
  74
  75         idx = ioread32(clk->mapped_reg) & 0x003f;
  76
  77         return clk->freq_table[idx].frequency;
  78 }
  79
  80 static int sh_clk_div6_set_parent(struct clk *clk, struct clk *parent)
  81 {
  82         struct clk_div_mult_table *table = &sh_clk_div6_table;
  83         u32 value;
  84         int ret, i;
  85
  86         if (!clk->parent_table || !clk->parent_num)
  87                 return -EINVAL;
  88
  89         /* Search the parent */
  90         for (i = 0; i < clk->parent_num; i++)
  91                 if (clk->parent_table[i] == parent)
  92                         break;
  93
  94         if (i == clk->parent_num)
  95                 return -ENODEV;
  96
  97         ret = clk_reparent(clk, parent);
  98         if (ret < 0)
  99                 return ret;
 100
 101         value = ioread32(clk->mapped_reg) &
 102                 ~(((1 << clk->src_width) - 1) << clk->src_shift);
 103
 104         iowrite32(value | (i << clk->src_shift), clk->mapped_reg);
 105
 106         /* Rebuild the frequency table */
 107         clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
 108                              table, NULL);
 109
 110         return 0;
 111 }
 112
 113 static int sh_clk_div6_set_rate(struct clk *clk, unsigned long rate)
 114 {
 115         unsigned long value;
 116         int idx;
 117
 118         idx = clk_rate_table_find(clk, clk->freq_table, rate);
 119         if (idx < 0)
 120                 return idx;
 121
 122         value = ioread32(clk->mapped_reg);
 123         value &= ~0x3f;
 124         value |= idx;
 125         iowrite32(value, clk->mapped_reg);
 126         return 0;
 127 }
 128
 129 static int sh_clk_div6_enable(struct clk *clk)
 130 {
 131         unsigned long value;
 132         int ret;
 133
 134         ret = sh_clk_div6_set_rate(clk, clk->rate);
 135         if (ret == 0) {
 136                 value = ioread32(clk->mapped_reg);
 137                 value &= ~0x100; /* clear stop bit to enable clock */
 138                 iowrite32(value, clk->mapped_reg);
 139         }
 140         return ret;
 141 }
 142
 143 static void sh_clk_div6_disable(struct clk *clk)
 144 {
 145         unsigned long value;
 146
 147         value = ioread32(clk->mapped_reg);
 148         value |= 0x100; /* stop clock */
 149         value |= 0x3f; /* VDIV bits must be non-zero, overwrite divider */
 150         iowrite32(value, clk->mapped_reg);
 151 }
 152
 153 static struct clk_ops sh_clk_div6_clk_ops = {
 154         .recalc         = sh_clk_div6_recalc,
 155         .round_rate     = sh_clk_div_round_rate,
 156         .set_rate       = sh_clk_div6_set_rate,
 157         .enable         = sh_clk_div6_enable,
 158         .disable        = sh_clk_div6_disable,
 159 };
 160
 161 static struct clk_ops sh_clk_div6_reparent_clk_ops = {
 162         .recalc         = sh_clk_div6_recalc,
 163         .round_rate     = sh_clk_div_round_rate,
 164         .set_rate       = sh_clk_div6_set_rate,
 165         .enable         = sh_clk_div6_enable,
 166         .disable        = sh_clk_div6_disable,
 167         .set_parent     = sh_clk_div6_set_parent,
 168 };
 169
 170 static int __init sh_clk_init_parent(struct clk *clk)
 171 {
 172         u32 val;
 173
 174         if (clk->parent)
 175                 return 0;
 176
 177         if (!clk->parent_table || !clk->parent_num)
 178                 return 0;
 179
 180         if (!clk->src_width) {
 181                 pr_err("sh_clk_init_parent: cannot select parent clock\n");
 182                 return -EINVAL;
 183         }
 184
 185         val  = (ioread32(clk->mapped_reg) >> clk->src_shift);
 186         val &= (1 << clk->src_width) - 1;
 187
 188         if (val >= clk->parent_num) {
 189                 pr_err("sh_clk_init_parent: parent table size failed\n");
 190                 return -EINVAL;
 191         }
 192
 193         clk->parent = clk->parent_table[val];
 194         if (!clk->parent) {
 195                 pr_err("sh_clk_init_parent: unable to set parent");
 196                 return -EINVAL;
 197         }
 198
 199         return 0;
 200 }
 201
 202 static int __init sh_clk_div6_register_ops(struct clk *clks, int nr,
 203                                            struct clk_ops *ops)
 204 {
 205         struct clk *clkp;
 206         void *freq_table;
 207         int nr_divs = sh_clk_div6_table.nr_divisors;
 208         int freq_table_size = sizeof(struct cpufreq_frequency_table);
 209         int ret = 0;
 210         int k;
 211
 212         freq_table_size *= (nr_divs + 1);
 213         freq_table = kzalloc(freq_table_size * nr, GFP_KERNEL);
 214         if (!freq_table) {
 215                 pr_err("sh_clk_div6_register: unable to alloc memory\n");
 216                 return -ENOMEM;
 217         }
 218
 219         for (k = 0; !ret && (k < nr); k++) {
 220                 clkp = clks + k;
 221
 222                 clkp->ops = ops;
 223                 clkp->freq_table = freq_table + (k * freq_table_size);
 224                 clkp->freq_table[nr_divs].frequency = CPUFREQ_TABLE_END;
 225                 ret = clk_register(clkp);
 226                 if (ret < 0)
 227                         break;
 228
 229                 ret = sh_clk_init_parent(clkp);
 230         }
 231
 232         return ret;
 233 }
 234
 235 int __init sh_clk_div6_register(struct clk *clks, int nr)
 236 {
 237         return sh_clk_div6_register_ops(clks, nr, &sh_clk_div6_clk_ops);
 238 }
 239
 240 int __init sh_clk_div6_reparent_register(struct clk *clks, int nr)
 241 {
 242         return sh_clk_div6_register_ops(clks, nr,
 243                                         &sh_clk_div6_reparent_clk_ops);
 244 }
 245
 246 static unsigned long sh_clk_div4_recalc(struct clk *clk)
 247 {
 248         struct clk_div4_table *d4t = clk->priv;
 249         struct clk_div_mult_table *table = d4t->div_mult_table;
 250         unsigned int idx;
 251
 252         clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
 253                              table, &clk->arch_flags);
 254
 255         idx = (ioread32(clk->mapped_reg) >> clk->enable_bit) & 0x000f;
 256
 257         return clk->freq_table[idx].frequency;
 258 }
 259
 260 static int sh_clk_div4_set_parent(struct clk *clk, struct clk *parent)
 261 {
 262         struct clk_div4_table *d4t = clk->priv;
 263         struct clk_div_mult_table *table = d4t->div_mult_table;
 264         u32 value;
 265         int ret;
 266
 267         /* we really need a better way to determine parent index, but for
 268          * now assume internal parent comes with CLK_ENABLE_ON_INIT set,
 269          * no CLK_ENABLE_ON_INIT means external clock...
 270          */
 271
 272         if (parent->flags & CLK_ENABLE_ON_INIT)
 273                 value = ioread32(clk->mapped_reg) & ~(1 << 7);
 274         else
 275                 value = ioread32(clk->mapped_reg) | (1 << 7);
 276
 277         ret = clk_reparent(clk, parent);
 278         if (ret < 0)
 279                 return ret;
 280
 281         iowrite32(value, clk->mapped_reg);
 282
 283         /* Rebiuld the frequency table */
 284         clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
 285                              table, &clk->arch_flags);
 286
 287         return 0;
 288 }
 289
 290 static int sh_clk_div4_set_rate(struct clk *clk, unsigned long rate)
 291 {
 292         struct clk_div4_table *d4t = clk->priv;
 293         unsigned long value;
 294         int idx = clk_rate_table_find(clk, clk->freq_table, rate);
 295         if (idx < 0)
 296                 return idx;
 297
 298         value = ioread32(clk->mapped_reg);
 299         value &= ~(0xf << clk->enable_bit);
 300         value |= (idx << clk->enable_bit);
 301         iowrite32(value, clk->mapped_reg);
 302
 303         if (d4t->kick)
 304                 d4t->kick(clk);
 305
 306         return 0;
 307 }
 308
 309 static int sh_clk_div4_enable(struct clk *clk)
 310 {
 311         iowrite32(ioread32(clk->mapped_reg) & ~(1 << 8), clk->mapped_reg);
 312         return 0;
 313 }
 314
 315 static void sh_clk_div4_disable(struct clk *clk)
 316 {
 317         iowrite32(ioread32(clk->mapped_reg) | (1 << 8), clk->mapped_reg);
 318 }
 319
 320 static struct clk_ops sh_clk_div4_clk_ops = {
 321         .recalc         = sh_clk_div4_recalc,
 322         .set_rate       = sh_clk_div4_set_rate,
 323         .round_rate     = sh_clk_div_round_rate,
 324 };
 325
 326 static struct clk_ops sh_clk_div4_enable_clk_ops = {
 327         .recalc         = sh_clk_div4_recalc,
 328         .set_rate       = sh_clk_div4_set_rate,
 329         .round_rate     = sh_clk_div_round_rate,
 330         .enable         = sh_clk_div4_enable,
 331         .disable        = sh_clk_div4_disable,
 332 };
 333
 334 static struct clk_ops sh_clk_div4_reparent_clk_ops = {
 335         .recalc         = sh_clk_div4_recalc,
 336         .set_rate       = sh_clk_div4_set_rate,
 337         .round_rate     = sh_clk_div_round_rate,
 338         .enable         = sh_clk_div4_enable,
 339         .disable        = sh_clk_div4_disable,
 340         .set_parent     = sh_clk_div4_set_parent,
 341 };
 342
 343 static int __init sh_clk_div4_register_ops(struct clk *clks, int nr,
 344                         struct clk_div4_table *table, struct clk_ops *ops)
 345 {
 346         struct clk *clkp;
 347         void *freq_table;
 348         int nr_divs = table->div_mult_table->nr_divisors;
 349         int freq_table_size = sizeof(struct cpufreq_frequency_table);
 350         int ret = 0;
 351         int k;
 352
 353         freq_table_size *= (nr_divs + 1);
 354         freq_table = kzalloc(freq_table_size * nr, GFP_KERNEL);
 355         if (!freq_table) {
 356                 pr_err("sh_clk_div4_register: unable to alloc memory\n");
 357                 return -ENOMEM;
 358         }
 359
 360         for (k = 0; !ret && (k < nr); k++) {
 361                 clkp = clks + k;
 362
 363                 clkp->ops = ops;
 364                 clkp->priv = table;
 365
 366                 clkp->freq_table = freq_table + (k * freq_table_size);
 367                 clkp->freq_table[nr_divs].frequency = CPUFREQ_TABLE_END;
 368
 369                 ret = clk_register(clkp);
 370         }
 371
 372         return ret;
 373 }
 374
 375 int __init sh_clk_div4_register(struct clk *clks, int nr,
 376                                 struct clk_div4_table *table)
 377 {
 378         return sh_clk_div4_register_ops(clks, nr, table, &sh_clk_div4_clk_ops);
 379 }
 380
 381 int __init sh_clk_div4_enable_register(struct clk *clks, int nr,
 382                                 struct clk_div4_table *table)
 383 {
 384         return sh_clk_div4_register_ops(clks, nr, table,
 385                                         &sh_clk_div4_enable_clk_ops);
 386 }
 387
 388 int __init sh_clk_div4_reparent_register(struct clk *clks, int nr,
 389                                 struct clk_div4_table *table)
 390 {
 391         return sh_clk_div4_register_ops(clks, nr, table,
 392                                         &sh_clk_div4_reparent_clk_ops);
 393 }