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 long mmp_clk_mix_determine_rate(struct clk_hw *hw, unsigned long rate,
 205                                         unsigned long *best_parent_rate,
 206                                         struct clk_hw **best_parent_clk)
 207 {
 208         struct mmp_clk_mix *mix = to_clk_mix(hw);
 209         struct mmp_clk_mix_clk_table *item;
 210         struct clk *parent, *parent_best, *mix_clk;
 211         unsigned long parent_rate, mix_rate, mix_rate_best, parent_rate_best;
 212         unsigned long gap, gap_best;
 213         u32 div_val_max;
 214         unsigned int div;
 215         int i, j;
 216
 217         mix_clk = hw->clk;
 218
 219         parent = NULL;
 220         mix_rate_best = 0;
 221         parent_rate_best = 0;
 222         gap_best = rate;
 223         parent_best = NULL;
 224
 225         if (mix->table) {
 226                 for (i = 0; i < mix->table_size; i++) {
 227                         item = &mix->table[i];
 228                         if (item->valid == 0)
 229                                 continue;
 230                         parent = clk_get_parent_by_index(mix_clk,
 231                                                         item->parent_index);
 232                         parent_rate = __clk_get_rate(parent);
 233                         mix_rate = parent_rate / item->divisor;
 234                         gap = abs(mix_rate - rate);
 235                         if (parent_best == NULL || gap < gap_best) {
 236                                 parent_best = parent;
 237                                 parent_rate_best = parent_rate;
 238                                 mix_rate_best = mix_rate;
 239                                 gap_best = gap;
 240                                 if (gap_best == 0)
 241                                         goto found;
 242                         }
 243                 }
 244         } else {
 245                 for (i = 0; i < __clk_get_num_parents(mix_clk); i++) {
 246                         parent = clk_get_parent_by_index(mix_clk, i);
 247                         parent_rate = __clk_get_rate(parent);
 248                         div_val_max = _get_maxdiv(mix);
 249                         for (j = 0; j < div_val_max; j++) {
 250                                 div = _get_div(mix, j);
 251                                 mix_rate = parent_rate / div;
 252                                 gap = abs(mix_rate - rate);
 253                                 if (parent_best == NULL || gap < gap_best) {
 254                                         parent_best = parent;
 255                                         parent_rate_best = parent_rate;
 256                                         mix_rate_best = mix_rate;
 257                                         gap_best = gap;
 258                                         if (gap_best == 0)
 259                                                 goto found;
 260                                 }
 261                         }
 262                 }
 263         }
 264
 265 found:
 266         *best_parent_rate = parent_rate_best;
 267         *best_parent_clk = __clk_get_hw(parent_best);
 268
 269         return mix_rate_best;
 270 }
 271
 272 static int mmp_clk_mix_set_rate_and_parent(struct clk_hw *hw,
 273                                                 unsigned long rate,
 274                                                 unsigned long parent_rate,
 275                                                 u8 index)
 276 {
 277         struct mmp_clk_mix *mix = to_clk_mix(hw);
 278         unsigned int div;
 279         u32 div_val, mux_val;
 280
 281         div = parent_rate / rate;
 282         div_val = _get_div_val(mix, div);
 283         mux_val = _get_mux_val(mix, index);
 284
 285         return _set_rate(mix, mux_val, div_val, 1, 1);
 286 }
 287
 288 static u8 mmp_clk_mix_get_parent(struct clk_hw *hw)
 289 {
 290         struct mmp_clk_mix *mix = to_clk_mix(hw);
 291         struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
 292         unsigned long flags = 0;
 293         u32 mux_div = 0;
 294         u8 width, shift;
 295         u32 mux_val;
 296
 297         if (mix->lock)
 298                 spin_lock_irqsave(mix->lock, flags);
 299
 300         if (mix->type == MMP_CLK_MIX_TYPE_V1
 301                 || mix->type == MMP_CLK_MIX_TYPE_V2)
 302                 mux_div = readl(ri->reg_clk_ctrl);
 303         else
 304                 mux_div = readl(ri->reg_clk_sel);
 305
 306         if (mix->lock)
 307                 spin_unlock_irqrestore(mix->lock, flags);
 308
 309         width = mix->reg_info.width_mux;
 310         shift = mix->reg_info.shift_mux;
 311
 312         mux_val = MMP_CLK_BITS_GET_VAL(mux_div, width, shift);
 313
 314         return _get_mux(mix, mux_val);
 315 }
 316
 317 static unsigned long mmp_clk_mix_recalc_rate(struct clk_hw *hw,
 318                                         unsigned long parent_rate)
 319 {
 320         struct mmp_clk_mix *mix = to_clk_mix(hw);
 321         struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
 322         unsigned long flags = 0;
 323         u32 mux_div = 0;
 324         u8 width, shift;
 325         unsigned int div;
 326
 327         if (mix->lock)
 328                 spin_lock_irqsave(mix->lock, flags);
 329
 330         if (mix->type == MMP_CLK_MIX_TYPE_V1
 331                 || mix->type == MMP_CLK_MIX_TYPE_V2)
 332                 mux_div = readl(ri->reg_clk_ctrl);
 333         else
 334                 mux_div = readl(ri->reg_clk_sel);
 335
 336         if (mix->lock)
 337                 spin_unlock_irqrestore(mix->lock, flags);
 338
 339         width = mix->reg_info.width_div;
 340         shift = mix->reg_info.shift_div;
 341
 342         div = _get_div(mix, MMP_CLK_BITS_GET_VAL(mux_div, width, shift));
 343
 344         return parent_rate / div;
 345 }
 346
 347 static int mmp_clk_set_parent(struct clk_hw *hw, u8 index)
 348 {
 349         struct mmp_clk_mix *mix = to_clk_mix(hw);
 350         struct mmp_clk_mix_clk_table *item;
 351         int i;
 352         u32 div_val, mux_val;
 353
 354         if (mix->table) {
 355                 for (i = 0; i < mix->table_size; i++) {
 356                         item = &mix->table[i];
 357                         if (item->valid == 0)
 358                                 continue;
 359                         if (item->parent_index == index)
 360                                 break;
 361                 }
 362                 if (i < mix->table_size) {
 363                         div_val = _get_div_val(mix, item->divisor);
 364                         mux_val = _get_mux_val(mix, item->parent_index);
 365                 } else
 366                         return -EINVAL;
 367         } else {
 368                 mux_val = _get_mux_val(mix, index);
 369                 div_val = 0;
 370         }
 371
 372         return _set_rate(mix, mux_val, div_val, 1, div_val ? 1 : 0);
 373 }
 374
 375 static int mmp_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 376                                 unsigned long best_parent_rate)
 377 {
 378         struct mmp_clk_mix *mix = to_clk_mix(hw);
 379         struct mmp_clk_mix_clk_table *item;
 380         unsigned long parent_rate;
 381         unsigned int best_divisor;
 382         struct clk *mix_clk, *parent;
 383         int i;
 384
 385         best_divisor = best_parent_rate / rate;
 386
 387         mix_clk = hw->clk;
 388         if (mix->table) {
 389                 for (i = 0; i < mix->table_size; i++) {
 390                         item = &mix->table[i];
 391                         if (item->valid == 0)
 392                                 continue;
 393                         parent = clk_get_parent_by_index(mix_clk,
 394                                                         item->parent_index);
 395                         parent_rate = __clk_get_rate(parent);
 396                         if (parent_rate == best_parent_rate
 397                                 && item->divisor == best_divisor)
 398                                 break;
 399                 }
 400                 if (i < mix->table_size)
 401                         return _set_rate(mix,
 402                                         _get_mux_val(mix, item->parent_index),
 403                                         _get_div_val(mix, item->divisor),
 404                                         1, 1);
 405                 else
 406                         return -EINVAL;
 407         } else {
 408                 for (i = 0; i < __clk_get_num_parents(mix_clk); i++) {
 409                         parent = clk_get_parent_by_index(mix_clk, i);
 410                         parent_rate = __clk_get_rate(parent);
 411                         if (parent_rate == best_parent_rate)
 412                                 break;
 413                 }
 414                 if (i < __clk_get_num_parents(mix_clk))
 415                         return _set_rate(mix, _get_mux_val(mix, i),
 416                                         _get_div_val(mix, best_divisor), 1, 1);
 417                 else
 418                         return -EINVAL;
 419         }
 420 }
 421
 422 static void mmp_clk_mix_init(struct clk_hw *hw)
 423 {
 424         struct mmp_clk_mix *mix = to_clk_mix(hw);
 425
 426         if (mix->table)
 427                 _filter_clk_table(mix, mix->table, mix->table_size);
 428 }
 429
 430 const struct clk_ops mmp_clk_mix_ops = {
 431         .determine_rate = mmp_clk_mix_determine_rate,
 432         .set_rate_and_parent = mmp_clk_mix_set_rate_and_parent,
 433         .set_rate = mmp_clk_set_rate,
 434         .set_parent = mmp_clk_set_parent,
 435         .get_parent = mmp_clk_mix_get_parent,
 436         .recalc_rate = mmp_clk_mix_recalc_rate,
 437         .init = mmp_clk_mix_init,
 438 };
 439
 440 struct clk *mmp_clk_register_mix(struct device *dev,
 441                                         const char *name,
 442                                         const char **parent_names,
 443                                         u8 num_parents,
 444                                         unsigned long flags,
 445                                         struct mmp_clk_mix_config *config,
 446                                         spinlock_t *lock)
 447 {
 448         struct mmp_clk_mix *mix;
 449         struct clk *clk;
 450         struct clk_init_data init;
 451         size_t table_bytes;
 452
 453         mix = kzalloc(sizeof(*mix), GFP_KERNEL);
 454         if (!mix) {
 455                 pr_err("%s:%s: could not allocate mmp mix clk\n",
 456                         __func__, name);
 457                 return ERR_PTR(-ENOMEM);
 458         }
 459
 460         init.name = name;
 461         init.flags = flags | CLK_GET_RATE_NOCACHE;
 462         init.parent_names = parent_names;
 463         init.num_parents = num_parents;
 464         init.ops = &mmp_clk_mix_ops;
 465
 466         memcpy(&mix->reg_info, &config->reg_info, sizeof(config->reg_info));
 467         if (config->table) {
 468                 table_bytes = sizeof(*config->table) * config->table_size;
 469                 mix->table = kzalloc(table_bytes, GFP_KERNEL);
 470                 if (!mix->table) {
 471                         pr_err("%s:%s: could not allocate mmp mix table\n",
 472                                 __func__, name);
 473                         kfree(mix);
 474                         return ERR_PTR(-ENOMEM);
 475                 }
 476                 memcpy(mix->table, config->table, table_bytes);
 477                 mix->table_size = config->table_size;
 478         }
 479
 480         if (config->mux_table) {
 481                 table_bytes = sizeof(u32) * num_parents;
 482                 mix->mux_table = kzalloc(table_bytes, GFP_KERNEL);
 483                 if (!mix->mux_table) {
 484                         pr_err("%s:%s: could not allocate mmp mix mux-table\n",
 485                                 __func__, name);
 486                         kfree(mix->table);
 487                         kfree(mix);
 488                         return ERR_PTR(-ENOMEM);
 489                 }
 490                 memcpy(mix->mux_table, config->mux_table, table_bytes);
 491         }
 492
 493         mix->div_flags = config->div_flags;
 494         mix->mux_flags = config->mux_flags;
 495         mix->lock = lock;
 496         mix->hw.init = &init;
 497
 498         if (config->reg_info.bit_fc >= 32)
 499                 mix->type = MMP_CLK_MIX_TYPE_V1;
 500         else if (config->reg_info.reg_clk_sel)
 501                 mix->type = MMP_CLK_MIX_TYPE_V3;
 502         else
 503                 mix->type = MMP_CLK_MIX_TYPE_V2;
 504         clk = clk_register(dev, &mix->hw);
 505
 506         if (IS_ERR(clk)) {
 507                 kfree(mix->mux_table);
 508                 kfree(mix->table);
 509                 kfree(mix);
 510         }
 511
 512         return clk;
 513 }