drivers/sh/clk/cpg.c

   1 /*
   2  * Helper routines for SuperH Clock Pulse Generator blocks (CPG).
   3  *
   4  *  Copyright (C) 2010  Magnus Damm
   5  *  Copyright (C) 2010 - 2012  Paul Mundt
   6  *
   7  * This file is subject to the terms and conditions of the GNU General Public
   8  * License.  See the file "COPYING" in the main directory of this archive
   9  * for more details.
  10  */
  11 #include <linux/clk.h>
  12 #include <linux/compiler.h>
  13 #include <linux/slab.h>
  14 #include <linux/io.h>
  15 #include <linux/sh_clk.h>
  16
  17 #define CPG_CKSTP_BIT   BIT(8)
  18
  19 static unsigned int sh_clk_read(struct clk *clk)
  20 {
  21         if (clk->flags & CLK_ENABLE_REG_8BIT)
  22                 return ioread8(clk->mapped_reg);
  23         else if (clk->flags & CLK_ENABLE_REG_16BIT)
  24                 return ioread16(clk->mapped_reg);
  25
  26         return ioread32(clk->mapped_reg);
  27 }
  28
  29 static void sh_clk_write(int value, struct clk *clk)
  30 {
  31         if (clk->flags & CLK_ENABLE_REG_8BIT)
  32                 iowrite8(value, clk->mapped_reg);
  33         else if (clk->flags & CLK_ENABLE_REG_16BIT)
  34                 iowrite16(value, clk->mapped_reg);
  35         else
  36                 iowrite32(value, clk->mapped_reg);
  37 }
  38
  39 static unsigned int r8(const void __iomem *addr)
  40 {
  41         return ioread8(addr);
  42 }
  43
  44 static unsigned int r16(const void __iomem *addr)
  45 {
  46         return ioread16(addr);
  47 }
  48
  49 static unsigned int r32(const void __iomem *addr)
  50 {
  51         return ioread32(addr);
  52 }
  53
  54 static int sh_clk_mstp_enable(struct clk *clk)
  55 {
  56         sh_clk_write(sh_clk_read(clk) & ~(1 << clk->enable_bit), clk);
  57         if (clk->status_reg) {
  58                 unsigned int (*read)(const void __iomem *addr);
  59                 int i;
  60                 void __iomem *mapped_status = (phys_addr_t)clk->status_reg -
  61                         (phys_addr_t)clk->enable_reg + clk->mapped_reg;
  62
  63                 if (clk->flags & CLK_ENABLE_REG_8BIT)
  64                         read = r8;
  65                 else if (clk->flags & CLK_ENABLE_REG_16BIT)
  66                         read = r16;
  67                 else
  68                         read = r32;
  69
  70                 for (i = 1000;
  71                      (read(mapped_status) & (1 << clk->enable_bit)) && i;
  72                      i--)
  73                         cpu_relax();
  74                 if (!i) {
  75                         pr_err("cpg: failed to enable %p[%d]\n",
  76                                clk->enable_reg, clk->enable_bit);
  77                         return -ETIMEDOUT;
  78                 }
  79         }
  80         return 0;
  81 }
  82
  83 static void sh_clk_mstp_disable(struct clk *clk)
  84 {
  85         sh_clk_write(sh_clk_read(clk) | (1 << clk->enable_bit), clk);
  86 }
  87
  88 static struct sh_clk_ops sh_clk_mstp_clk_ops = {
  89         .enable         = sh_clk_mstp_enable,
  90         .disable        = sh_clk_mstp_disable,
  91         .recalc         = followparent_recalc,
  92 };
  93
  94 int __init sh_clk_mstp_register(struct clk *clks, int nr)
  95 {
  96         struct clk *clkp;
  97         int ret = 0;
  98         int k;
  99
 100         for (k = 0; !ret && (k < nr); k++) {
 101                 clkp = clks + k;
 102                 clkp->ops = &sh_clk_mstp_clk_ops;
 103                 ret |= clk_register(clkp);
 104         }
 105
 106         return ret;
 107 }
 108
 109 /*
 110  * Div/mult table lookup helpers
 111  */
 112 static inline struct clk_div_table *clk_to_div_table(struct clk *clk)
 113 {
 114         return clk->priv;
 115 }
 116
 117 static inline struct clk_div_mult_table *clk_to_div_mult_table(struct clk *clk)
 118 {
 119         return clk_to_div_table(clk)->div_mult_table;
 120 }
 121
 122 /*
 123  * Common div ops
 124  */
 125 static long sh_clk_div_round_rate(struct clk *clk, unsigned long rate)
 126 {
 127         return clk_rate_table_round(clk, clk->freq_table, rate);
 128 }
 129
 130 static unsigned long sh_clk_div_recalc(struct clk *clk)
 131 {
 132         struct clk_div_mult_table *table = clk_to_div_mult_table(clk);
 133         unsigned int idx;
 134
 135         clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
 136                              table, clk->arch_flags ? &clk->arch_flags : NULL);
 137
 138         idx = (sh_clk_read(clk) >> clk->enable_bit) & clk->div_mask;
 139
 140         return clk->freq_table[idx].frequency;
 141 }
 142
 143 static int sh_clk_div_set_rate(struct clk *clk, unsigned long rate)
 144 {
 145         struct clk_div_table *dt = clk_to_div_table(clk);
 146         unsigned long value;
 147         int idx;
 148
 149         idx = clk_rate_table_find(clk, clk->freq_table, rate);
 150         if (idx < 0)
 151                 return idx;
 152
 153         value = sh_clk_read(clk);
 154         value &= ~(clk->div_mask << clk->enable_bit);
 155         value |= (idx << clk->enable_bit);
 156         sh_clk_write(value, clk);
 157
 158         /* XXX: Should use a post-change notifier */
 159         if (dt->kick)
 160                 dt->kick(clk);
 161
 162         return 0;
 163 }
 164
 165 static int sh_clk_div_enable(struct clk *clk)
 166 {
 167         if (clk->div_mask == SH_CLK_DIV6_MSK) {
 168                 int ret = sh_clk_div_set_rate(clk, clk->rate);
 169                 if (ret < 0)
 170                         return ret;
 171         }
 172
 173         sh_clk_write(sh_clk_read(clk) & ~CPG_CKSTP_BIT, clk);
 174         return 0;
 175 }
 176
 177 static void sh_clk_div_disable(struct clk *clk)
 178 {
 179         unsigned int val;
 180
 181         val = sh_clk_read(clk);
 182         val |= CPG_CKSTP_BIT;
 183
 184         /*
 185          * div6 clocks require the divisor field to be non-zero or the
 186          * above CKSTP toggle silently fails. Ensure that the divisor
 187          * array is reset to its initial state on disable.
 188          */
 189         if (clk->flags & CLK_MASK_DIV_ON_DISABLE)
 190                 val |= clk->div_mask;
 191
 192         sh_clk_write(val, clk);
 193 }
 194
 195 static struct sh_clk_ops sh_clk_div_clk_ops = {
 196         .recalc         = sh_clk_div_recalc,
 197         .set_rate       = sh_clk_div_set_rate,
 198         .round_rate     = sh_clk_div_round_rate,
 199 };
 200
 201 static struct sh_clk_ops sh_clk_div_enable_clk_ops = {
 202         .recalc         = sh_clk_div_recalc,
 203         .set_rate       = sh_clk_div_set_rate,
 204         .round_rate     = sh_clk_div_round_rate,
 205         .enable         = sh_clk_div_enable,
 206         .disable        = sh_clk_div_disable,
 207 };
 208
 209 static int __init sh_clk_init_parent(struct clk *clk)
 210 {
 211         u32 val;
 212
 213         if (clk->parent)
 214                 return 0;
 215
 216         if (!clk->parent_table || !clk->parent_num)
 217                 return 0;
 218
 219         if (!clk->src_width) {
 220                 pr_err("sh_clk_init_parent: cannot select parent clock\n");
 221                 return -EINVAL;
 222         }
 223
 224         val  = (sh_clk_read(clk) >> clk->src_shift);
 225         val &= (1 << clk->src_width) - 1;
 226
 227         if (val >= clk->parent_num) {
 228                 pr_err("sh_clk_init_parent: parent table size failed\n");
 229                 return -EINVAL;
 230         }
 231
 232         clk_reparent(clk, clk->parent_table[val]);
 233         if (!clk->parent) {
 234                 pr_err("sh_clk_init_parent: unable to set parent");
 235                 return -EINVAL;
 236         }
 237
 238         return 0;
 239 }
 240
 241 static int __init sh_clk_div_register_ops(struct clk *clks, int nr,
 242                         struct clk_div_table *table, struct sh_clk_ops *ops)
 243 {
 244         struct clk *clkp;
 245         void *freq_table;
 246         int nr_divs = table->div_mult_table->nr_divisors;
 247         int freq_table_size = sizeof(struct cpufreq_frequency_table);
 248         int ret = 0;
 249         int k;
 250
 251         freq_table_size *= (nr_divs + 1);
 252         freq_table = kzalloc(freq_table_size * nr, GFP_KERNEL);
 253         if (!freq_table) {
 254                 pr_err("%s: unable to alloc memory\n", __func__);
 255                 return -ENOMEM;
 256         }
 257
 258         for (k = 0; !ret && (k < nr); k++) {
 259                 clkp = clks + k;
 260
 261                 clkp->ops = ops;
 262                 clkp->priv = table;
 263
 264                 clkp->freq_table = freq_table + (k * freq_table_size);
 265                 clkp->freq_table[nr_divs].frequency = CPUFREQ_TABLE_END;
 266
 267                 ret = clk_register(clkp);
 268                 if (ret == 0)
 269                         ret = sh_clk_init_parent(clkp);
 270         }
 271
 272         return ret;
 273 }
 274
 275 /*
 276  * div6 support
 277  */
 278 static int sh_clk_div6_divisors[64] = {
 279         1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
 280         17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32,
 281         33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,
 282         49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64
 283 };
 284
 285 static struct clk_div_mult_table div6_div_mult_table = {
 286         .divisors = sh_clk_div6_divisors,
 287         .nr_divisors = ARRAY_SIZE(sh_clk_div6_divisors),
 288 };
 289
 290 static struct clk_div_table sh_clk_div6_table = {
 291         .div_mult_table = &div6_div_mult_table,
 292 };
 293
 294 static int sh_clk_div6_set_parent(struct clk *clk, struct clk *parent)
 295 {
 296         struct clk_div_mult_table *table = clk_to_div_mult_table(clk);
 297         u32 value;
 298         int ret, i;
 299
 300         if (!clk->parent_table || !clk->parent_num)
 301                 return -EINVAL;
 302
 303         /* Search the parent */
 304         for (i = 0; i < clk->parent_num; i++)
 305                 if (clk->parent_table[i] == parent)
 306                         break;
 307
 308         if (i == clk->parent_num)
 309                 return -ENODEV;
 310
 311         ret = clk_reparent(clk, parent);
 312         if (ret < 0)
 313                 return ret;
 314
 315         value = sh_clk_read(clk) &
 316                 ~(((1 << clk->src_width) - 1) << clk->src_shift);
 317
 318         sh_clk_write(value | (i << clk->src_shift), clk);
 319
 320         /* Rebuild the frequency table */
 321         clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
 322                              table, NULL);
 323
 324         return 0;
 325 }
 326
 327 static struct sh_clk_ops sh_clk_div6_reparent_clk_ops = {
 328         .recalc         = sh_clk_div_recalc,
 329         .round_rate     = sh_clk_div_round_rate,
 330         .set_rate       = sh_clk_div_set_rate,
 331         .enable         = sh_clk_div_enable,
 332         .disable        = sh_clk_div_disable,
 333         .set_parent     = sh_clk_div6_set_parent,
 334 };
 335
 336 int __init sh_clk_div6_register(struct clk *clks, int nr)
 337 {
 338         return sh_clk_div_register_ops(clks, nr, &sh_clk_div6_table,
 339                                        &sh_clk_div_enable_clk_ops);
 340 }
 341
 342 int __init sh_clk_div6_reparent_register(struct clk *clks, int nr)
 343 {
 344         return sh_clk_div_register_ops(clks, nr, &sh_clk_div6_table,
 345                                        &sh_clk_div6_reparent_clk_ops);
 346 }
 347
 348 /*
 349  * div4 support
 350  */
 351 static int sh_clk_div4_set_parent(struct clk *clk, struct clk *parent)
 352 {
 353         struct clk_div_mult_table *table = clk_to_div_mult_table(clk);
 354         u32 value;
 355         int ret;
 356
 357         /* we really need a better way to determine parent index, but for
 358          * now assume internal parent comes with CLK_ENABLE_ON_INIT set,
 359          * no CLK_ENABLE_ON_INIT means external clock...
 360          */
 361
 362         if (parent->flags & CLK_ENABLE_ON_INIT)
 363                 value = sh_clk_read(clk) & ~(1 << 7);
 364         else
 365                 value = sh_clk_read(clk) | (1 << 7);
 366
 367         ret = clk_reparent(clk, parent);
 368         if (ret < 0)
 369                 return ret;
 370
 371         sh_clk_write(value, clk);
 372
 373         /* Rebiuld the frequency table */
 374         clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
 375                              table, &clk->arch_flags);
 376
 377         return 0;
 378 }
 379
 380 static struct sh_clk_ops sh_clk_div4_reparent_clk_ops = {
 381         .recalc         = sh_clk_div_recalc,
 382         .set_rate       = sh_clk_div_set_rate,
 383         .round_rate     = sh_clk_div_round_rate,
 384         .enable         = sh_clk_div_enable,
 385         .disable        = sh_clk_div_disable,
 386         .set_parent     = sh_clk_div4_set_parent,
 387 };
 388
 389 int __init sh_clk_div4_register(struct clk *clks, int nr,
 390                                 struct clk_div4_table *table)
 391 {
 392         return sh_clk_div_register_ops(clks, nr, table, &sh_clk_div_clk_ops);
 393 }
 394
 395 int __init sh_clk_div4_enable_register(struct clk *clks, int nr,
 396                                 struct clk_div4_table *table)
 397 {
 398         return sh_clk_div_register_ops(clks, nr, table,
 399                                        &sh_clk_div_enable_clk_ops);
 400 }
 401
 402 int __init sh_clk_div4_reparent_register(struct clk *clks, int nr,
 403                                 struct clk_div4_table *table)
 404 {
 405         return sh_clk_div_register_ops(clks, nr, table,
 406                                        &sh_clk_div4_reparent_clk_ops);
 407 }
 408
 409 /* FSI-DIV */
 410 static unsigned long fsidiv_recalc(struct clk *clk)
 411 {
 412         u32 value;
 413
 414         value = __raw_readl(clk->mapping->base);
 415
 416         value >>= 16;
 417         if (value < 2)
 418                 return clk->parent->rate;
 419
 420         return clk->parent->rate / value;
 421 }
 422
 423 static long fsidiv_round_rate(struct clk *clk, unsigned long rate)
 424 {
 425         return clk_rate_div_range_round(clk, 1, 0xffff, rate);
 426 }
 427
 428 static void fsidiv_disable(struct clk *clk)
 429 {
 430         __raw_writel(0, clk->mapping->base);
 431 }
 432
 433 static int fsidiv_enable(struct clk *clk)
 434 {
 435         u32 value;
 436
 437         value  = __raw_readl(clk->mapping->base) >> 16;
 438         if (value < 2)
 439                 return 0;
 440
 441         __raw_writel((value << 16) | 0x3, clk->mapping->base);
 442
 443         return 0;
 444 }
 445
 446 static int fsidiv_set_rate(struct clk *clk, unsigned long rate)
 447 {
 448         int idx;
 449
 450         idx = (clk->parent->rate / rate) & 0xffff;
 451         if (idx < 2)
 452                 __raw_writel(0, clk->mapping->base);
 453         else
 454                 __raw_writel(idx << 16, clk->mapping->base);
 455
 456         return 0;
 457 }
 458
 459 static struct sh_clk_ops fsidiv_clk_ops = {
 460         .recalc         = fsidiv_recalc,
 461         .round_rate     = fsidiv_round_rate,
 462         .set_rate       = fsidiv_set_rate,
 463         .enable         = fsidiv_enable,
 464         .disable        = fsidiv_disable,
 465 };
 466
 467 int __init sh_clk_fsidiv_register(struct clk *clks, int nr)
 468 {
 469         struct clk_mapping *map;
 470         int i;
 471
 472         for (i = 0; i < nr; i++) {
 473
 474                 map = kzalloc(sizeof(struct clk_mapping), GFP_KERNEL);
 475                 if (!map) {
 476                         pr_err("%s: unable to alloc memory\n", __func__);
 477                         return -ENOMEM;
 478                 }
 479
 480                 /* clks[i].enable_reg came from SH_CLK_FSIDIV() */
 481                 map->phys               = (phys_addr_t)clks[i].enable_reg;
 482                 map->len                = 8;
 483
 484                 clks[i].enable_reg      = 0; /* remove .enable_reg */
 485                 clks[i].ops             = &fsidiv_clk_ops;
 486                 clks[i].mapping         = map;
 487
 488                 clk_register(&clks[i]);
 489         }
 490
 491         return 0;
 492 }