drivers/clk/mmp/clk-mix.c

   1 /*
   2  * mmp mix(div and mux) clock operation source file
   3  *
   4  * Copyright (C) 2014 Marvell
   5  * Chao Xie <chao.xie@marvell.com>
   6  *
   7  * This file is licensed under the terms of the GNU General Public
   8  * License version 2. This program is licensed "as is" without any
   9  * warranty of any kind, whether express or implied.
  10  */
  11
  12 #include <linux/clk-provider.h>
  13 #include <linux/slab.h>
  14 #include <linux/io.h>
  15 #include <linux/err.h>
  16
  17 #include "clk.h"
  18
  19 /*
  20  * The mix clock is a clock combined mux and div type clock.
  21  * Because the div field and mux field need to be set at same
  22  * time, we can not divide it into 2 types of clock
  23  */
  24
  25 #define to_clk_mix(hw)  container_of(hw, struct mmp_clk_mix, hw)
  26
  27 static unsigned int _get_maxdiv(struct mmp_clk_mix *mix)
  28 {
  29         unsigned int div_mask = (1 << mix->reg_info.width_div) - 1;
  30         unsigned int maxdiv = 0;
  31         struct clk_div_table *clkt;
  32
  33         if (mix->div_flags & CLK_DIVIDER_ONE_BASED)
  34                 return div_mask;
  35         if (mix->div_flags & CLK_DIVIDER_POWER_OF_TWO)
  36                 return 1 << div_mask;
  37         if (mix->div_table) {
  38                 for (clkt = mix->div_table; clkt->div; clkt++)
  39                         if (clkt->div > maxdiv)
  40                                 maxdiv = clkt->div;
  41                 return maxdiv;
  42         }
  43         return div_mask + 1;
  44 }
  45
  46 static unsigned int _get_div(struct mmp_clk_mix *mix, unsigned int val)
  47 {
  48         struct clk_div_table *clkt;
  49
  50         if (mix->div_flags & CLK_DIVIDER_ONE_BASED)
  51                 return val;
  52         if (mix->div_flags & CLK_DIVIDER_POWER_OF_TWO)
  53                 return 1 << val;
  54         if (mix->div_table) {
  55                 for (clkt = mix->div_table; clkt->div; clkt++)
  56                         if (clkt->val == val)
  57                                 return clkt->div;
  58                 if (clkt->div == 0)
  59                         return 0;
  60         }
  61         return val + 1;
  62 }
  63
  64 static unsigned int _get_mux(struct mmp_clk_mix *mix, unsigned int val)
  65 {
  66         int num_parents = __clk_get_num_parents(mix->hw.clk);
  67         int i;
  68
  69         if (mix->mux_flags & CLK_MUX_INDEX_BIT)
  70                 return ffs(val) - 1;
  71         if (mix->mux_flags & CLK_MUX_INDEX_ONE)
  72                 return val - 1;
  73         if (mix->mux_table) {
  74                 for (i = 0; i < num_parents; i++)
  75                         if (mix->mux_table[i] == val)
  76                                 return i;
  77                 if (i == num_parents)
  78                         return 0;
  79         }
  80
  81         return val;
  82 }
  83 static unsigned int _get_div_val(struct mmp_clk_mix *mix, unsigned int div)
  84 {
  85         struct clk_div_table *clkt;
  86
  87         if (mix->div_flags & CLK_DIVIDER_ONE_BASED)
  88                 return div;
  89         if (mix->div_flags & CLK_DIVIDER_POWER_OF_TWO)
  90                 return __ffs(div);
  91         if (mix->div_table) {
  92                 for (clkt = mix->div_table; clkt->div; clkt++)
  93                         if (clkt->div == div)
  94                                 return clkt->val;
  95                 if (clkt->div == 0)
  96                         return 0;
  97         }
  98
  99         return div - 1;
 100 }
 101
 102 static unsigned int _get_mux_val(struct mmp_clk_mix *mix, unsigned int mux)
 103 {
 104         if (mix->mux_table)
 105                 return mix->mux_table[mux];
 106
 107         return mux;
 108 }
 109
 110 static void _filter_clk_table(struct mmp_clk_mix *mix,
 111                                 struct mmp_clk_mix_clk_table *table,
 112                                 unsigned int table_size)
 113 {
 114         int i;
 115         struct mmp_clk_mix_clk_table *item;
 116         struct clk *parent, *clk;
 117         unsigned long parent_rate;
 118
 119         clk = mix->hw.clk;
 120
 121         for (i = 0; i < table_size; i++) {
 122                 item = &table[i];
 123                 parent = clk_get_parent_by_index(clk, item->parent_index);
 124                 parent_rate = __clk_get_rate(parent);
 125                 if (parent_rate % item->rate) {
 126                         item->valid = 0;
 127                 } else {
 128                         item->divisor = parent_rate / item->rate;
 129                         item->valid = 1;
 130                 }
 131         }
 132 }
 133
 134 static int _set_rate(struct mmp_clk_mix *mix, u32 mux_val, u32 div_val,
 135                         unsigned int change_mux, unsigned int change_div)
 136 {
 137         struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
 138         u8 width, shift;
 139         u32 mux_div, fc_req;
 140         int ret, timeout = 50;
 141         unsigned long flags = 0;
 142
 143         if (!change_mux && !change_div)
 144                 return -EINVAL;
 145
 146         if (mix->lock)
 147                 spin_lock_irqsave(mix->lock, flags);
 148
 149         if (mix->type == MMP_CLK_MIX_TYPE_V1
 150                 || mix->type == MMP_CLK_MIX_TYPE_V2)
 151                 mux_div = readl(ri->reg_clk_ctrl);
 152         else
 153                 mux_div = readl(ri->reg_clk_sel);
 154
 155         if (change_div) {
 156                 width = ri->width_div;
 157                 shift = ri->shift_div;
 158                 mux_div &= ~MMP_CLK_BITS_MASK(width, shift);
 159                 mux_div |= MMP_CLK_BITS_SET_VAL(div_val, width, shift);
 160         }
 161
 162         if (change_mux) {
 163                 width = ri->width_mux;
 164                 shift = ri->shift_mux;
 165                 mux_div &= ~MMP_CLK_BITS_MASK(width, shift);
 166                 mux_div |= MMP_CLK_BITS_SET_VAL(mux_val, width, shift);
 167         }
 168
 169         if (mix->type == MMP_CLK_MIX_TYPE_V1) {
 170                 writel(mux_div, ri->reg_clk_ctrl);
 171         } else if (mix->type == MMP_CLK_MIX_TYPE_V2) {
 172                 mux_div |= (1 << ri->bit_fc);
 173                 writel(mux_div, ri->reg_clk_ctrl);
 174
 175                 do {
 176                         fc_req = readl(ri->reg_clk_ctrl);
 177                         timeout--;
 178                         if (!(fc_req & (1 << ri->bit_fc)))
 179                                 break;
 180                 } while (timeout);
 181
 182                 if (timeout == 0) {
 183                         pr_err("%s:%s cannot do frequency change\n",
 184                                 __func__, __clk_get_name(mix->hw.clk));
 185                         ret = -EBUSY;
 186                         goto error;
 187                 }
 188         } else {
 189                 fc_req = readl(ri->reg_clk_ctrl);
 190                 fc_req |= 1 << ri->bit_fc;
 191                 writel(fc_req, ri->reg_clk_ctrl);
 192                 writel(mux_div, ri->reg_clk_sel);
 193                 fc_req &= ~(1 << ri->bit_fc);
 194         }
 195
 196         ret = 0;
 197 error:
 198         if (mix->lock)
 199                 spin_unlock_irqrestore(mix->lock, flags);
 200
 201         return ret;
 202 }
 203
 204 static int mmp_clk_mix_determine_rate(struct clk_hw *hw,
 205                                       struct clk_rate_request *req)
 206 {
 207         struct mmp_clk_mix *mix = to_clk_mix(hw);
 208         struct mmp_clk_mix_clk_table *item;
 209         struct clk *parent, *parent_best, *mix_clk;
 210         unsigned long parent_rate, mix_rate, mix_rate_best, parent_rate_best;
 211         unsigned long gap, gap_best;
 212         u32 div_val_max;
 213         unsigned int div;
 214         int i, j;
 215
 216         mix_clk = hw->clk;
 217
 218         parent = NULL;
 219         mix_rate_best = 0;
 220         parent_rate_best = 0;
 221         gap_best = ULONG_MAX;
 222         parent_best = NULL;
 223
 224         if (mix->table) {
 225                 for (i = 0; i < mix->table_size; i++) {
 226                         item = &mix->table[i];
 227                         if (item->valid == 0)
 228                                 continue;
 229                         parent = clk_get_parent_by_index(mix_clk,
 230                                                         item->parent_index);
 231                         parent_rate = __clk_get_rate(parent);
 232                         mix_rate = parent_rate / item->divisor;
 233                         gap = abs(mix_rate - req->rate);
 234                         if (parent_best == NULL || gap < gap_best) {
 235                                 parent_best = parent;
 236                                 parent_rate_best = parent_rate;
 237                                 mix_rate_best = mix_rate;
 238                                 gap_best = gap;
 239                                 if (gap_best == 0)
 240                                         goto found;
 241                         }
 242                 }
 243         } else {
 244                 for (i = 0; i < __clk_get_num_parents(mix_clk); i++) {
 245                         parent = clk_get_parent_by_index(mix_clk, i);
 246                         parent_rate = __clk_get_rate(parent);
 247                         div_val_max = _get_maxdiv(mix);
 248                         for (j = 0; j < div_val_max; j++) {
 249                                 div = _get_div(mix, j);
 250                                 mix_rate = parent_rate / div;
 251                                 gap = abs(mix_rate - req->rate);
 252                                 if (parent_best == NULL || gap < gap_best) {
 253                                         parent_best = parent;
 254                                         parent_rate_best = parent_rate;
 255                                         mix_rate_best = mix_rate;
 256                                         gap_best = gap;
 257                                         if (gap_best == 0)
 258                                                 goto found;
 259                                 }
 260                         }
 261                 }
 262         }
 263
 264 found:
 265         if (!parent_best)
 266                 return -EINVAL;
 267
 268         req->best_parent_rate = parent_rate_best;
 269         req->best_parent_hw = __clk_get_hw(parent_best);
 270         req->rate = mix_rate_best;
 271
 272         return 0;
 273 }
 274
 275 static int mmp_clk_mix_set_rate_and_parent(struct clk_hw *hw,
 276                                                 unsigned long rate,
 277                                                 unsigned long parent_rate,
 278                                                 u8 index)
 279 {
 280         struct mmp_clk_mix *mix = to_clk_mix(hw);
 281         unsigned int div;
 282         u32 div_val, mux_val;
 283
 284         div = parent_rate / rate;
 285         div_val = _get_div_val(mix, div);
 286         mux_val = _get_mux_val(mix, index);
 287
 288         return _set_rate(mix, mux_val, div_val, 1, 1);
 289 }
 290
 291 static u8 mmp_clk_mix_get_parent(struct clk_hw *hw)
 292 {
 293         struct mmp_clk_mix *mix = to_clk_mix(hw);
 294         struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
 295         unsigned long flags = 0;
 296         u32 mux_div = 0;
 297         u8 width, shift;
 298         u32 mux_val;
 299
 300         if (mix->lock)
 301                 spin_lock_irqsave(mix->lock, flags);
 302
 303         if (mix->type == MMP_CLK_MIX_TYPE_V1
 304                 || mix->type == MMP_CLK_MIX_TYPE_V2)
 305                 mux_div = readl(ri->reg_clk_ctrl);
 306         else
 307                 mux_div = readl(ri->reg_clk_sel);
 308
 309         if (mix->lock)
 310                 spin_unlock_irqrestore(mix->lock, flags);
 311
 312         width = mix->reg_info.width_mux;
 313         shift = mix->reg_info.shift_mux;
 314
 315         mux_val = MMP_CLK_BITS_GET_VAL(mux_div, width, shift);
 316
 317         return _get_mux(mix, mux_val);
 318 }
 319
 320 static unsigned long mmp_clk_mix_recalc_rate(struct clk_hw *hw,
 321                                         unsigned long parent_rate)
 322 {
 323         struct mmp_clk_mix *mix = to_clk_mix(hw);
 324         struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
 325         unsigned long flags = 0;
 326         u32 mux_div = 0;
 327         u8 width, shift;
 328         unsigned int div;
 329
 330         if (mix->lock)
 331                 spin_lock_irqsave(mix->lock, flags);
 332
 333         if (mix->type == MMP_CLK_MIX_TYPE_V1
 334                 || mix->type == MMP_CLK_MIX_TYPE_V2)
 335                 mux_div = readl(ri->reg_clk_ctrl);
 336         else
 337                 mux_div = readl(ri->reg_clk_sel);
 338
 339         if (mix->lock)
 340                 spin_unlock_irqrestore(mix->lock, flags);
 341
 342         width = mix->reg_info.width_div;
 343         shift = mix->reg_info.shift_div;
 344
 345         div = _get_div(mix, MMP_CLK_BITS_GET_VAL(mux_div, width, shift));
 346
 347         return parent_rate / div;
 348 }
 349
 350 static int mmp_clk_set_parent(struct clk_hw *hw, u8 index)
 351 {
 352         struct mmp_clk_mix *mix = to_clk_mix(hw);
 353         struct mmp_clk_mix_clk_table *item;
 354         int i;
 355         u32 div_val, mux_val;
 356
 357         if (mix->table) {
 358                 for (i = 0; i < mix->table_size; i++) {
 359                         item = &mix->table[i];
 360                         if (item->valid == 0)
 361                                 continue;
 362                         if (item->parent_index == index)
 363                                 break;
 364                 }
 365                 if (i < mix->table_size) {
 366                         div_val = _get_div_val(mix, item->divisor);
 367                         mux_val = _get_mux_val(mix, item->parent_index);
 368                 } else
 369                         return -EINVAL;
 370         } else {
 371                 mux_val = _get_mux_val(mix, index);
 372                 div_val = 0;
 373         }
 374
 375         return _set_rate(mix, mux_val, div_val, 1, div_val ? 1 : 0);
 376 }
 377
 378 static int mmp_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 379                                 unsigned long best_parent_rate)
 380 {
 381         struct mmp_clk_mix *mix = to_clk_mix(hw);
 382         struct mmp_clk_mix_clk_table *item;
 383         unsigned long parent_rate;
 384         unsigned int best_divisor;
 385         struct clk *mix_clk, *parent;
 386         int i;
 387
 388         best_divisor = best_parent_rate / rate;
 389
 390         mix_clk = hw->clk;
 391         if (mix->table) {
 392                 for (i = 0; i < mix->table_size; i++) {
 393                         item = &mix->table[i];
 394                         if (item->valid == 0)
 395                                 continue;
 396                         parent = clk_get_parent_by_index(mix_clk,
 397                                                         item->parent_index);
 398                         parent_rate = __clk_get_rate(parent);
 399                         if (parent_rate == best_parent_rate
 400                                 && item->divisor == best_divisor)
 401                                 break;
 402                 }
 403                 if (i < mix->table_size)
 404                         return _set_rate(mix,
 405                                         _get_mux_val(mix, item->parent_index),
 406                                         _get_div_val(mix, item->divisor),
 407                                         1, 1);
 408                 else
 409                         return -EINVAL;
 410         } else {
 411                 for (i = 0; i < __clk_get_num_parents(mix_clk); i++) {
 412                         parent = clk_get_parent_by_index(mix_clk, i);
 413                         parent_rate = __clk_get_rate(parent);
 414                         if (parent_rate == best_parent_rate)
 415                                 break;
 416                 }
 417                 if (i < __clk_get_num_parents(mix_clk))
 418                         return _set_rate(mix, _get_mux_val(mix, i),
 419                                         _get_div_val(mix, best_divisor), 1, 1);
 420                 else
 421                         return -EINVAL;
 422         }
 423 }
 424
 425 static void mmp_clk_mix_init(struct clk_hw *hw)
 426 {
 427         struct mmp_clk_mix *mix = to_clk_mix(hw);
 428
 429         if (mix->table)
 430                 _filter_clk_table(mix, mix->table, mix->table_size);
 431 }
 432
 433 const struct clk_ops mmp_clk_mix_ops = {
 434         .determine_rate = mmp_clk_mix_determine_rate,
 435         .set_rate_and_parent = mmp_clk_mix_set_rate_and_parent,
 436         .set_rate = mmp_clk_set_rate,
 437         .set_parent = mmp_clk_set_parent,
 438         .get_parent = mmp_clk_mix_get_parent,
 439         .recalc_rate = mmp_clk_mix_recalc_rate,
 440         .init = mmp_clk_mix_init,
 441 };
 442
 443 struct clk *mmp_clk_register_mix(struct device *dev,
 444                                         const char *name,
 445                                         const char **parent_names,
 446                                         u8 num_parents,
 447                                         unsigned long flags,
 448                                         struct mmp_clk_mix_config *config,
 449                                         spinlock_t *lock)
 450 {
 451         struct mmp_clk_mix *mix;
 452         struct clk *clk;
 453         struct clk_init_data init;
 454         size_t table_bytes;
 455
 456         mix = kzalloc(sizeof(*mix), GFP_KERNEL);
 457         if (!mix) {
 458                 pr_err("%s:%s: could not allocate mmp mix clk\n",
 459                         __func__, name);
 460                 return ERR_PTR(-ENOMEM);
 461         }
 462
 463         init.name = name;
 464         init.flags = flags | CLK_GET_RATE_NOCACHE;
 465         init.parent_names = parent_names;
 466         init.num_parents = num_parents;
 467         init.ops = &mmp_clk_mix_ops;
 468
 469         memcpy(&mix->reg_info, &config->reg_info, sizeof(config->reg_info));
 470         if (config->table) {
 471                 table_bytes = sizeof(*config->table) * config->table_size;
 472                 mix->table = kzalloc(table_bytes, GFP_KERNEL);
 473                 if (!mix->table) {
 474                         pr_err("%s:%s: could not allocate mmp mix table\n",
 475                                 __func__, name);
 476                         kfree(mix);
 477                         return ERR_PTR(-ENOMEM);
 478                 }
 479                 memcpy(mix->table, config->table, table_bytes);
 480                 mix->table_size = config->table_size;
 481         }
 482
 483         if (config->mux_table) {
 484                 table_bytes = sizeof(u32) * num_parents;
 485                 mix->mux_table = kzalloc(table_bytes, GFP_KERNEL);
 486                 if (!mix->mux_table) {
 487                         pr_err("%s:%s: could not allocate mmp mix mux-table\n",
 488                                 __func__, name);
 489                         kfree(mix->table);
 490                         kfree(mix);
 491                         return ERR_PTR(-ENOMEM);
 492                 }
 493                 memcpy(mix->mux_table, config->mux_table, table_bytes);
 494         }
 495
 496         mix->div_flags = config->div_flags;
 497         mix->mux_flags = config->mux_flags;
 498         mix->lock = lock;
 499         mix->hw.init = &init;
 500
 501         if (config->reg_info.bit_fc >= 32)
 502                 mix->type = MMP_CLK_MIX_TYPE_V1;
 503         else if (config->reg_info.reg_clk_sel)
 504                 mix->type = MMP_CLK_MIX_TYPE_V3;
 505         else
 506                 mix->type = MMP_CLK_MIX_TYPE_V2;
 507         clk = clk_register(dev, &mix->hw);
 508
 509         if (IS_ERR(clk)) {
 510                 kfree(mix->mux_table);
 511                 kfree(mix->table);
 512                 kfree(mix);
 513         }
 514
 515         return clk;
 516 }