drivers/clk/at91/clk-peripheral.c

   1 /*
   2  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  */
  10
  11 #include <linux/clk-provider.h>
  12 #include <linux/clkdev.h>
  13 #include <linux/clk/at91_pmc.h>
  14 #include <linux/of.h>
  15 #include <linux/mfd/syscon.h>
  16 #include <linux/regmap.h>
  17
  18 #include "pmc.h"
  19
  20 DEFINE_SPINLOCK(pmc_pcr_lock);
  21
  22 #define PERIPHERAL_MAX          64
  23
  24 #define PERIPHERAL_AT91RM9200   0
  25 #define PERIPHERAL_AT91SAM9X5   1
  26
  27 #define PERIPHERAL_ID_MIN       2
  28 #define PERIPHERAL_ID_MAX       31
  29 #define PERIPHERAL_MASK(id)     (1 << ((id) & PERIPHERAL_ID_MAX))
  30
  31 #define PERIPHERAL_RSHIFT_MASK  0x3
  32 #define PERIPHERAL_RSHIFT(val)  (((val) >> 16) & PERIPHERAL_RSHIFT_MASK)
  33
  34 #define PERIPHERAL_MAX_SHIFT    3
  35
  36 struct clk_peripheral {
  37         struct clk_hw hw;
  38         struct regmap *regmap;
  39         u32 id;
  40 };
  41
  42 #define to_clk_peripheral(hw) container_of(hw, struct clk_peripheral, hw)
  43
  44 struct clk_sam9x5_peripheral {
  45         struct clk_hw hw;
  46         struct regmap *regmap;
  47         struct clk_range range;
  48         spinlock_t *lock;
  49         u32 id;
  50         u32 div;
  51         bool auto_div;
  52 };
  53
  54 #define to_clk_sam9x5_peripheral(hw) \
  55         container_of(hw, struct clk_sam9x5_peripheral, hw)
  56
  57 static int clk_peripheral_enable(struct clk_hw *hw)
  58 {
  59         struct clk_peripheral *periph = to_clk_peripheral(hw);
  60         int offset = AT91_PMC_PCER;
  61         u32 id = periph->id;
  62
  63         if (id < PERIPHERAL_ID_MIN)
  64                 return 0;
  65         if (id > PERIPHERAL_ID_MAX)
  66                 offset = AT91_PMC_PCER1;
  67         regmap_write(periph->regmap, offset, PERIPHERAL_MASK(id));
  68
  69         return 0;
  70 }
  71
  72 static void clk_peripheral_disable(struct clk_hw *hw)
  73 {
  74         struct clk_peripheral *periph = to_clk_peripheral(hw);
  75         int offset = AT91_PMC_PCDR;
  76         u32 id = periph->id;
  77
  78         if (id < PERIPHERAL_ID_MIN)
  79                 return;
  80         if (id > PERIPHERAL_ID_MAX)
  81                 offset = AT91_PMC_PCDR1;
  82         regmap_write(periph->regmap, offset, PERIPHERAL_MASK(id));
  83 }
  84
  85 static int clk_peripheral_is_enabled(struct clk_hw *hw)
  86 {
  87         struct clk_peripheral *periph = to_clk_peripheral(hw);
  88         int offset = AT91_PMC_PCSR;
  89         unsigned int status;
  90         u32 id = periph->id;
  91
  92         if (id < PERIPHERAL_ID_MIN)
  93                 return 1;
  94         if (id > PERIPHERAL_ID_MAX)
  95                 offset = AT91_PMC_PCSR1;
  96         regmap_read(periph->regmap, offset, &status);
  97
  98         return status & PERIPHERAL_MASK(id) ? 1 : 0;
  99 }
 100
 101 static const struct clk_ops peripheral_ops = {
 102         .enable = clk_peripheral_enable,
 103         .disable = clk_peripheral_disable,
 104         .is_enabled = clk_peripheral_is_enabled,
 105 };
 106
 107 static struct clk_hw * __init
 108 at91_clk_register_peripheral(struct regmap *regmap, const char *name,
 109                              const char *parent_name, u32 id)
 110 {
 111         struct clk_peripheral *periph;
 112         struct clk_init_data init;
 113         struct clk_hw *hw;
 114         int ret;
 115
 116         if (!name || !parent_name || id > PERIPHERAL_ID_MAX)
 117                 return ERR_PTR(-EINVAL);
 118
 119         periph = kzalloc(sizeof(*periph), GFP_KERNEL);
 120         if (!periph)
 121                 return ERR_PTR(-ENOMEM);
 122
 123         init.name = name;
 124         init.ops = &peripheral_ops;
 125         init.parent_names = (parent_name ? &parent_name : NULL);
 126         init.num_parents = (parent_name ? 1 : 0);
 127         init.flags = 0;
 128
 129         periph->id = id;
 130         periph->hw.init = &init;
 131         periph->regmap = regmap;
 132
 133         hw = &periph->hw;
 134         ret = clk_hw_register(NULL, &periph->hw);
 135         if (ret) {
 136                 kfree(periph);
 137                 hw = ERR_PTR(ret);
 138         }
 139
 140         return hw;
 141 }
 142
 143 static void clk_sam9x5_peripheral_autodiv(struct clk_sam9x5_peripheral *periph)
 144 {
 145         struct clk_hw *parent;
 146         unsigned long parent_rate;
 147         int shift = 0;
 148
 149         if (!periph->auto_div)
 150                 return;
 151
 152         if (periph->range.max) {
 153                 parent = clk_hw_get_parent_by_index(&periph->hw, 0);
 154                 parent_rate = clk_hw_get_rate(parent);
 155                 if (!parent_rate)
 156                         return;
 157
 158                 for (; shift < PERIPHERAL_MAX_SHIFT; shift++) {
 159                         if (parent_rate >> shift <= periph->range.max)
 160                                 break;
 161                 }
 162         }
 163
 164         periph->auto_div = false;
 165         periph->div = shift;
 166 }
 167
 168 static int clk_sam9x5_peripheral_enable(struct clk_hw *hw)
 169 {
 170         struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
 171         unsigned long flags;
 172
 173         if (periph->id < PERIPHERAL_ID_MIN)
 174                 return 0;
 175
 176         spin_lock_irqsave(periph->lock, flags);
 177         regmap_write(periph->regmap, AT91_PMC_PCR,
 178                      (periph->id & AT91_PMC_PCR_PID_MASK));
 179         regmap_update_bits(periph->regmap, AT91_PMC_PCR,
 180                            AT91_PMC_PCR_DIV_MASK | AT91_PMC_PCR_CMD |
 181                            AT91_PMC_PCR_EN,
 182                            AT91_PMC_PCR_DIV(periph->div) |
 183                            AT91_PMC_PCR_CMD |
 184                            AT91_PMC_PCR_EN);
 185         spin_unlock_irqrestore(periph->lock, flags);
 186
 187         return 0;
 188 }
 189
 190 static void clk_sam9x5_peripheral_disable(struct clk_hw *hw)
 191 {
 192         struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
 193         unsigned long flags;
 194
 195         if (periph->id < PERIPHERAL_ID_MIN)
 196                 return;
 197
 198         spin_lock_irqsave(periph->lock, flags);
 199         regmap_write(periph->regmap, AT91_PMC_PCR,
 200                      (periph->id & AT91_PMC_PCR_PID_MASK));
 201         regmap_update_bits(periph->regmap, AT91_PMC_PCR,
 202                            AT91_PMC_PCR_EN | AT91_PMC_PCR_CMD,
 203                            AT91_PMC_PCR_CMD);
 204         spin_unlock_irqrestore(periph->lock, flags);
 205 }
 206
 207 static int clk_sam9x5_peripheral_is_enabled(struct clk_hw *hw)
 208 {
 209         struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
 210         unsigned long flags;
 211         unsigned int status;
 212
 213         if (periph->id < PERIPHERAL_ID_MIN)
 214                 return 1;
 215
 216         spin_lock_irqsave(periph->lock, flags);
 217         regmap_write(periph->regmap, AT91_PMC_PCR,
 218                      (periph->id & AT91_PMC_PCR_PID_MASK));
 219         regmap_read(periph->regmap, AT91_PMC_PCR, &status);
 220         spin_unlock_irqrestore(periph->lock, flags);
 221
 222         return status & AT91_PMC_PCR_EN ? 1 : 0;
 223 }
 224
 225 static unsigned long
 226 clk_sam9x5_peripheral_recalc_rate(struct clk_hw *hw,
 227                                   unsigned long parent_rate)
 228 {
 229         struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
 230         unsigned long flags;
 231         unsigned int status;
 232
 233         if (periph->id < PERIPHERAL_ID_MIN)
 234                 return parent_rate;
 235
 236         spin_lock_irqsave(periph->lock, flags);
 237         regmap_write(periph->regmap, AT91_PMC_PCR,
 238                      (periph->id & AT91_PMC_PCR_PID_MASK));
 239         regmap_read(periph->regmap, AT91_PMC_PCR, &status);
 240         spin_unlock_irqrestore(periph->lock, flags);
 241
 242         if (status & AT91_PMC_PCR_EN) {
 243                 periph->div = PERIPHERAL_RSHIFT(status);
 244                 periph->auto_div = false;
 245         } else {
 246                 clk_sam9x5_peripheral_autodiv(periph);
 247         }
 248
 249         return parent_rate >> periph->div;
 250 }
 251
 252 static long clk_sam9x5_peripheral_round_rate(struct clk_hw *hw,
 253                                              unsigned long rate,
 254                                              unsigned long *parent_rate)
 255 {
 256         int shift = 0;
 257         unsigned long best_rate;
 258         unsigned long best_diff;
 259         unsigned long cur_rate = *parent_rate;
 260         unsigned long cur_diff;
 261         struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
 262
 263         if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max)
 264                 return *parent_rate;
 265
 266         if (periph->range.max) {
 267                 for (; shift <= PERIPHERAL_MAX_SHIFT; shift++) {
 268                         cur_rate = *parent_rate >> shift;
 269                         if (cur_rate <= periph->range.max)
 270                                 break;
 271                 }
 272         }
 273
 274         if (rate >= cur_rate)
 275                 return cur_rate;
 276
 277         best_diff = cur_rate - rate;
 278         best_rate = cur_rate;
 279         for (; shift <= PERIPHERAL_MAX_SHIFT; shift++) {
 280                 cur_rate = *parent_rate >> shift;
 281                 if (cur_rate < rate)
 282                         cur_diff = rate - cur_rate;
 283                 else
 284                         cur_diff = cur_rate - rate;
 285
 286                 if (cur_diff < best_diff) {
 287                         best_diff = cur_diff;
 288                         best_rate = cur_rate;
 289                 }
 290
 291                 if (!best_diff || cur_rate < rate)
 292                         break;
 293         }
 294
 295         return best_rate;
 296 }
 297
 298 static int clk_sam9x5_peripheral_set_rate(struct clk_hw *hw,
 299                                           unsigned long rate,
 300                                           unsigned long parent_rate)
 301 {
 302         int shift;
 303         struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
 304         if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max) {
 305                 if (parent_rate == rate)
 306                         return 0;
 307                 else
 308                         return -EINVAL;
 309         }
 310
 311         if (periph->range.max && rate > periph->range.max)
 312                 return -EINVAL;
 313
 314         for (shift = 0; shift <= PERIPHERAL_MAX_SHIFT; shift++) {
 315                 if (parent_rate >> shift == rate) {
 316                         periph->auto_div = false;
 317                         periph->div = shift;
 318                         return 0;
 319                 }
 320         }
 321
 322         return -EINVAL;
 323 }
 324
 325 static const struct clk_ops sam9x5_peripheral_ops = {
 326         .enable = clk_sam9x5_peripheral_enable,
 327         .disable = clk_sam9x5_peripheral_disable,
 328         .is_enabled = clk_sam9x5_peripheral_is_enabled,
 329         .recalc_rate = clk_sam9x5_peripheral_recalc_rate,
 330         .round_rate = clk_sam9x5_peripheral_round_rate,
 331         .set_rate = clk_sam9x5_peripheral_set_rate,
 332 };
 333
 334 static struct clk_hw * __init
 335 at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock,
 336                                     const char *name, const char *parent_name,
 337                                     u32 id, const struct clk_range *range)
 338 {
 339         struct clk_sam9x5_peripheral *periph;
 340         struct clk_init_data init;
 341         struct clk_hw *hw;
 342         int ret;
 343
 344         if (!name || !parent_name)
 345                 return ERR_PTR(-EINVAL);
 346
 347         periph = kzalloc(sizeof(*periph), GFP_KERNEL);
 348         if (!periph)
 349                 return ERR_PTR(-ENOMEM);
 350
 351         init.name = name;
 352         init.ops = &sam9x5_peripheral_ops;
 353         init.parent_names = (parent_name ? &parent_name : NULL);
 354         init.num_parents = (parent_name ? 1 : 0);
 355         init.flags = 0;
 356
 357         periph->id = id;
 358         periph->hw.init = &init;
 359         periph->div = 0;
 360         periph->regmap = regmap;
 361         periph->lock = lock;
 362         periph->auto_div = true;
 363         periph->range = *range;
 364
 365         hw = &periph->hw;
 366         ret = clk_hw_register(NULL, &periph->hw);
 367         if (ret) {
 368                 kfree(periph);
 369                 hw = ERR_PTR(ret);
 370         } else {
 371                 clk_sam9x5_peripheral_autodiv(periph);
 372                 pmc_register_id(id);
 373         }
 374
 375         return hw;
 376 }
 377
 378 static void __init
 379 of_at91_clk_periph_setup(struct device_node *np, u8 type)
 380 {
 381         int num;
 382         u32 id;
 383         struct clk_hw *hw;
 384         const char *parent_name;
 385         const char *name;
 386         struct device_node *periphclknp;
 387         struct regmap *regmap;
 388
 389         parent_name = of_clk_get_parent_name(np, 0);
 390         if (!parent_name)
 391                 return;
 392
 393         num = of_get_child_count(np);
 394         if (!num || num > PERIPHERAL_MAX)
 395                 return;
 396
 397         regmap = syscon_node_to_regmap(of_get_parent(np));
 398         if (IS_ERR(regmap))
 399                 return;
 400
 401         for_each_child_of_node(np, periphclknp) {
 402                 if (of_property_read_u32(periphclknp, "reg", &id))
 403                         continue;
 404
 405                 if (id >= PERIPHERAL_MAX)
 406                         continue;
 407
 408                 if (of_property_read_string(np, "clock-output-names", &name))
 409                         name = periphclknp->name;
 410
 411                 if (type == PERIPHERAL_AT91RM9200) {
 412                         hw = at91_clk_register_peripheral(regmap, name,
 413                                                            parent_name, id);
 414                 } else {
 415                         struct clk_range range = CLK_RANGE(0, 0);
 416
 417                         of_at91_get_clk_range(periphclknp,
 418                                               "atmel,clk-output-range",
 419                                               &range);
 420
 421                         hw = at91_clk_register_sam9x5_peripheral(regmap,
 422                                                                   &pmc_pcr_lock,
 423                                                                   name,
 424                                                                   parent_name,
 425                                                                   id, &range);
 426                 }
 427
 428                 if (IS_ERR(hw))
 429                         continue;
 430
 431                 of_clk_add_hw_provider(periphclknp, of_clk_hw_simple_get, hw);
 432         }
 433 }
 434
 435 static void __init of_at91rm9200_clk_periph_setup(struct device_node *np)
 436 {
 437         of_at91_clk_periph_setup(np, PERIPHERAL_AT91RM9200);
 438 }
 439 CLK_OF_DECLARE(at91rm9200_clk_periph, "atmel,at91rm9200-clk-peripheral",
 440                of_at91rm9200_clk_periph_setup);
 441
 442 static void __init of_at91sam9x5_clk_periph_setup(struct device_node *np)
 443 {
 444         of_at91_clk_periph_setup(np, PERIPHERAL_AT91SAM9X5);
 445 }
 446 CLK_OF_DECLARE(at91sam9x5_clk_periph, "atmel,at91sam9x5-clk-peripheral",
 447                of_at91sam9x5_clk_periph_setup);
 448