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_hw_get_num_parents(&mix->hw);
  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_hw *parent, *hw;
 117         unsigned long parent_rate;
 118
 119         hw = &mix->hw;
 120
 121         for (i = 0; i < table_size; i++) {
 122                 item = &table[i];
 123                 parent = clk_hw_get_parent_by_index(hw, item->parent_index);
 124                 parent_rate = clk_hw_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_hw_get_name(&mix->hw));
 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_hw *parent, *parent_best;
 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
 217         mix_rate_best = 0;
 218         parent_rate_best = 0;
 219         gap_best = ULONG_MAX;
 220         parent_best = NULL;
 221
 222         if (mix->table) {
 223                 for (i = 0; i < mix->table_size; i++) {
 224                         item = &mix->table[i];
 225                         if (item->valid == 0)
 226                                 continue;
 227                         parent = clk_hw_get_parent_by_index(hw,
 228                                                         item->parent_index);
 229                         parent_rate = clk_hw_get_rate(parent);
 230                         mix_rate = parent_rate / item->divisor;
 231                         gap = abs(mix_rate - req->rate);
 232                         if (!parent_best || gap < gap_best) {
 233                                 parent_best = parent;
 234                                 parent_rate_best = parent_rate;
 235                                 mix_rate_best = mix_rate;
 236                                 gap_best = gap;
 237                                 if (gap_best == 0)
 238                                         goto found;
 239                         }
 240                 }
 241         } else {
 242                 for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
 243                         parent = clk_hw_get_parent_by_index(hw, i);
 244                         parent_rate = clk_hw_get_rate(parent);
 245                         div_val_max = _get_maxdiv(mix);
 246                         for (j = 0; j < div_val_max; j++) {
 247                                 div = _get_div(mix, j);
 248                                 mix_rate = parent_rate / div;
 249                                 gap = abs(mix_rate - req->rate);
 250                                 if (!parent_best || gap < gap_best) {
 251                                         parent_best = parent;
 252                                         parent_rate_best = parent_rate;
 253                                         mix_rate_best = mix_rate;
 254                                         gap_best = gap;
 255                                         if (gap_best == 0)
 256                                                 goto found;
 257                                 }
 258                         }
 259                 }
 260         }
 261
 262 found:
 263         if (!parent_best)
 264                 return -EINVAL;
 265
 266         req->best_parent_rate = parent_rate_best;
 267         req->best_parent_hw = parent_best;
 268         req->rate = mix_rate_best;
 269
 270         return 0;
 271 }
 272
 273 static int mmp_clk_mix_set_rate_and_parent(struct clk_hw *hw,
 274                                                 unsigned long rate,
 275                                                 unsigned long parent_rate,
 276                                                 u8 index)
 277 {
 278         struct mmp_clk_mix *mix = to_clk_mix(hw);
 279         unsigned int div;
 280         u32 div_val, mux_val;
 281
 282         div = parent_rate / rate;
 283         div_val = _get_div_val(mix, div);
 284         mux_val = _get_mux_val(mix, index);
 285
 286         return _set_rate(mix, mux_val, div_val, 1, 1);
 287 }
 288
 289 static u8 mmp_clk_mix_get_parent(struct clk_hw *hw)
 290 {
 291         struct mmp_clk_mix *mix = to_clk_mix(hw);
 292         struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
 293         unsigned long flags = 0;
 294         u32 mux_div = 0;
 295         u8 width, shift;
 296         u32 mux_val;
 297
 298         if (mix->lock)
 299                 spin_lock_irqsave(mix->lock, flags);
 300
 301         if (mix->type == MMP_CLK_MIX_TYPE_V1
 302                 || mix->type == MMP_CLK_MIX_TYPE_V2)
 303                 mux_div = readl(ri->reg_clk_ctrl);
 304         else
 305                 mux_div = readl(ri->reg_clk_sel);
 306
 307         if (mix->lock)
 308                 spin_unlock_irqrestore(mix->lock, flags);
 309
 310         width = mix->reg_info.width_mux;
 311         shift = mix->reg_info.shift_mux;
 312
 313         mux_val = MMP_CLK_BITS_GET_VAL(mux_div, width, shift);
 314
 315         return _get_mux(mix, mux_val);
 316 }
 317
 318 static unsigned long mmp_clk_mix_recalc_rate(struct clk_hw *hw,
 319                                         unsigned long parent_rate)
 320 {
 321         struct mmp_clk_mix *mix = to_clk_mix(hw);
 322         struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
 323         unsigned long flags = 0;
 324         u32 mux_div = 0;
 325         u8 width, shift;
 326         unsigned int div;
 327
 328         if (mix->lock)
 329                 spin_lock_irqsave(mix->lock, flags);
 330
 331         if (mix->type == MMP_CLK_MIX_TYPE_V1
 332                 || mix->type == MMP_CLK_MIX_TYPE_V2)
 333                 mux_div = readl(ri->reg_clk_ctrl);
 334         else
 335                 mux_div = readl(ri->reg_clk_sel);
 336
 337         if (mix->lock)
 338                 spin_unlock_irqrestore(mix->lock, flags);
 339
 340         width = mix->reg_info.width_div;
 341         shift = mix->reg_info.shift_div;
 342
 343         div = _get_div(mix, MMP_CLK_BITS_GET_VAL(mux_div, width, shift));
 344
 345         return parent_rate / div;
 346 }
 347
 348 static int mmp_clk_set_parent(struct clk_hw *hw, u8 index)
 349 {
 350         struct mmp_clk_mix *mix = to_clk_mix(hw);
 351         struct mmp_clk_mix_clk_table *item;
 352         int i;
 353         u32 div_val, mux_val;
 354
 355         if (mix->table) {
 356                 for (i = 0; i < mix->table_size; i++) {
 357                         item = &mix->table[i];
 358                         if (item->valid == 0)
 359                                 continue;
 360                         if (item->parent_index == index)
 361                                 break;
 362                 }
 363                 if (i < mix->table_size) {
 364                         div_val = _get_div_val(mix, item->divisor);
 365                         mux_val = _get_mux_val(mix, item->parent_index);
 366                 } else
 367                         return -EINVAL;
 368         } else {
 369                 mux_val = _get_mux_val(mix, index);
 370                 div_val = 0;
 371         }
 372
 373         return _set_rate(mix, mux_val, div_val, 1, div_val ? 1 : 0);
 374 }
 375
 376 static int mmp_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 377                                 unsigned long best_parent_rate)
 378 {
 379         struct mmp_clk_mix *mix = to_clk_mix(hw);
 380         struct mmp_clk_mix_clk_table *item;
 381         unsigned long parent_rate;
 382         unsigned int best_divisor;
 383         struct clk_hw *parent;
 384         int i;
 385
 386         best_divisor = best_parent_rate / rate;
 387
 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_hw_get_parent_by_index(hw,
 394                                                         item->parent_index);
 395                         parent_rate = clk_hw_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_hw_get_num_parents(hw); i++) {
 409                         parent = clk_hw_get_parent_by_index(hw, i);
 410                         parent_rate = clk_hw_get_rate(parent);
 411                         if (parent_rate == best_parent_rate)
 412                                 break;
 413                 }
 414                 if (i < clk_hw_get_num_parents(hw))
 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                 return ERR_PTR(-ENOMEM);
 456
 457         init.name = name;
 458         init.flags = flags | CLK_GET_RATE_NOCACHE;
 459         init.parent_names = parent_names;
 460         init.num_parents = num_parents;
 461         init.ops = &mmp_clk_mix_ops;
 462
 463         memcpy(&mix->reg_info, &config->reg_info, sizeof(config->reg_info));
 464         if (config->table) {
 465                 table_bytes = sizeof(*config->table) * config->table_size;
 466                 mix->table = kmemdup(config->table, table_bytes, GFP_KERNEL);
 467                 if (!mix->table)
 468                         goto free_mix;
 469
 470                 mix->table_size = config->table_size;
 471         }
 472
 473         if (config->mux_table) {
 474                 table_bytes = sizeof(u32) * num_parents;
 475                 mix->mux_table = kmemdup(config->mux_table, table_bytes,
 476                                          GFP_KERNEL);
 477                 if (!mix->mux_table) {
 478                         kfree(mix->table);
 479                         goto free_mix;
 480                 }
 481         }
 482
 483         mix->div_flags = config->div_flags;
 484         mix->mux_flags = config->mux_flags;
 485         mix->lock = lock;
 486         mix->hw.init = &init;
 487
 488         if (config->reg_info.bit_fc >= 32)
 489                 mix->type = MMP_CLK_MIX_TYPE_V1;
 490         else if (config->reg_info.reg_clk_sel)
 491                 mix->type = MMP_CLK_MIX_TYPE_V3;
 492         else
 493                 mix->type = MMP_CLK_MIX_TYPE_V2;
 494         clk = clk_register(dev, &mix->hw);
 495
 496         if (IS_ERR(clk)) {
 497                 kfree(mix->mux_table);
 498                 kfree(mix->table);
 499                 kfree(mix);
 500         }
 501
 502         return clk;
 503
 504 free_mix:
 505         kfree(mix);
 506         return ERR_PTR(-ENOMEM);
 507 }