kernel/drivers/clk/at91/clk-main.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/delay.h>
  15 #include <linux/of.h>
  16 #include <linux/mfd/syscon.h>
  17 #include <linux/regmap.h>
  18
  19 #include "pmc.h"
  20
  21 #define SLOW_CLOCK_FREQ         32768
  22 #define MAINF_DIV               16
  23 #define MAINFRDY_TIMEOUT        (((MAINF_DIV + 1) * USEC_PER_SEC) / \
  24                                  SLOW_CLOCK_FREQ)
  25 #define MAINF_LOOP_MIN_WAIT     (USEC_PER_SEC / SLOW_CLOCK_FREQ)
  26 #define MAINF_LOOP_MAX_WAIT     MAINFRDY_TIMEOUT
  27
  28 #define MOR_KEY_MASK            (0xff << 16)
  29
  30 struct clk_main_osc {
  31         struct clk_hw hw;
  32         struct regmap *regmap;
  33 };
  34
  35 #define to_clk_main_osc(hw) container_of(hw, struct clk_main_osc, hw)
  36
  37 struct clk_main_rc_osc {
  38         struct clk_hw hw;
  39         struct regmap *regmap;
  40         unsigned long frequency;
  41         unsigned long accuracy;
  42 };
  43
  44 #define to_clk_main_rc_osc(hw) container_of(hw, struct clk_main_rc_osc, hw)
  45
  46 struct clk_rm9200_main {
  47         struct clk_hw hw;
  48         struct regmap *regmap;
  49 };
  50
  51 #define to_clk_rm9200_main(hw) container_of(hw, struct clk_rm9200_main, hw)
  52
  53 struct clk_sam9x5_main {
  54         struct clk_hw hw;
  55         struct regmap *regmap;
  56         u8 parent;
  57 };
  58
  59 #define to_clk_sam9x5_main(hw) container_of(hw, struct clk_sam9x5_main, hw)
  60
  61 static inline bool clk_main_osc_ready(struct regmap *regmap)
  62 {
  63         unsigned int status;
  64
  65         regmap_read(regmap, AT91_PMC_SR, &status);
  66
  67         return status & AT91_PMC_MOSCS;
  68 }
  69
  70 static int clk_main_osc_prepare(struct clk_hw *hw)
  71 {
  72         struct clk_main_osc *osc = to_clk_main_osc(hw);
  73         struct regmap *regmap = osc->regmap;
  74         u32 tmp;
  75
  76         regmap_read(regmap, AT91_CKGR_MOR, &tmp);
  77         tmp &= ~MOR_KEY_MASK;
  78
  79         if (tmp & AT91_PMC_OSCBYPASS)
  80                 return 0;
  81
  82         if (!(tmp & AT91_PMC_MOSCEN)) {
  83                 tmp |= AT91_PMC_MOSCEN | AT91_PMC_KEY;
  84                 regmap_write(regmap, AT91_CKGR_MOR, tmp);
  85         }
  86
  87         while (!clk_main_osc_ready(regmap))
  88                 cpu_relax();
  89
  90         return 0;
  91 }
  92
  93 static void clk_main_osc_unprepare(struct clk_hw *hw)
  94 {
  95         struct clk_main_osc *osc = to_clk_main_osc(hw);
  96         struct regmap *regmap = osc->regmap;
  97         u32 tmp;
  98
  99         regmap_read(regmap, AT91_CKGR_MOR, &tmp);
 100         if (tmp & AT91_PMC_OSCBYPASS)
 101                 return;
 102
 103         if (!(tmp & AT91_PMC_MOSCEN))
 104                 return;
 105
 106         tmp &= ~(AT91_PMC_KEY | AT91_PMC_MOSCEN);
 107         regmap_write(regmap, AT91_CKGR_MOR, tmp | AT91_PMC_KEY);
 108 }
 109
 110 static int clk_main_osc_is_prepared(struct clk_hw *hw)
 111 {
 112         struct clk_main_osc *osc = to_clk_main_osc(hw);
 113         struct regmap *regmap = osc->regmap;
 114         u32 tmp, status;
 115
 116         regmap_read(regmap, AT91_CKGR_MOR, &tmp);
 117         if (tmp & AT91_PMC_OSCBYPASS)
 118                 return 1;
 119
 120         regmap_read(regmap, AT91_PMC_SR, &status);
 121
 122         return (status & AT91_PMC_MOSCS) && (tmp & AT91_PMC_MOSCEN);
 123 }
 124
 125 static const struct clk_ops main_osc_ops = {
 126         .prepare = clk_main_osc_prepare,
 127         .unprepare = clk_main_osc_unprepare,
 128         .is_prepared = clk_main_osc_is_prepared,
 129 };
 130
 131 static struct clk * __init
 132 at91_clk_register_main_osc(struct regmap *regmap,
 133                            const char *name,
 134                            const char *parent_name,
 135                            bool bypass)
 136 {
 137         struct clk_main_osc *osc;
 138         struct clk *clk = NULL;
 139         struct clk_init_data init;
 140
 141         if (!name || !parent_name)
 142                 return ERR_PTR(-EINVAL);
 143
 144         osc = kzalloc(sizeof(*osc), GFP_KERNEL);
 145         if (!osc)
 146                 return ERR_PTR(-ENOMEM);
 147
 148         init.name = name;
 149         init.ops = &main_osc_ops;
 150         init.parent_names = &parent_name;
 151         init.num_parents = 1;
 152         init.flags = CLK_IGNORE_UNUSED;
 153
 154         osc->hw.init = &init;
 155         osc->regmap = regmap;
 156
 157         if (bypass)
 158                 regmap_update_bits(regmap,
 159                                    AT91_CKGR_MOR, MOR_KEY_MASK |
 160                                    AT91_PMC_MOSCEN,
 161                                    AT91_PMC_OSCBYPASS | AT91_PMC_KEY);
 162
 163         clk = clk_register(NULL, &osc->hw);
 164         if (IS_ERR(clk))
 165                 kfree(osc);
 166
 167         return clk;
 168 }
 169
 170 static void __init of_at91rm9200_clk_main_osc_setup(struct device_node *np)
 171 {
 172         struct clk *clk;
 173         const char *name = np->name;
 174         const char *parent_name;
 175         struct regmap *regmap;
 176         bool bypass;
 177
 178         of_property_read_string(np, "clock-output-names", &name);
 179         bypass = of_property_read_bool(np, "atmel,osc-bypass");
 180         parent_name = of_clk_get_parent_name(np, 0);
 181
 182         regmap = syscon_node_to_regmap(of_get_parent(np));
 183         if (IS_ERR(regmap))
 184                 return;
 185
 186         clk = at91_clk_register_main_osc(regmap, name, parent_name, bypass);
 187         if (IS_ERR(clk))
 188                 return;
 189
 190         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 191 }
 192 CLK_OF_DECLARE(at91rm9200_clk_main_osc, "atmel,at91rm9200-clk-main-osc",
 193                of_at91rm9200_clk_main_osc_setup);
 194
 195 static bool clk_main_rc_osc_ready(struct regmap *regmap)
 196 {
 197         unsigned int status;
 198
 199         regmap_read(regmap, AT91_PMC_SR, &status);
 200
 201         return status & AT91_PMC_MOSCRCS;
 202 }
 203
 204 static int clk_main_rc_osc_prepare(struct clk_hw *hw)
 205 {
 206         struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
 207         struct regmap *regmap = osc->regmap;
 208         unsigned int mor;
 209
 210         regmap_read(regmap, AT91_CKGR_MOR, &mor);
 211
 212         if (!(mor & AT91_PMC_MOSCRCEN))
 213                 regmap_update_bits(regmap, AT91_CKGR_MOR,
 214                                    MOR_KEY_MASK | AT91_PMC_MOSCRCEN,
 215                                    AT91_PMC_MOSCRCEN | AT91_PMC_KEY);
 216
 217         while (!clk_main_rc_osc_ready(regmap))
 218                 cpu_relax();
 219
 220         return 0;
 221 }
 222
 223 static void clk_main_rc_osc_unprepare(struct clk_hw *hw)
 224 {
 225         struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
 226         struct regmap *regmap = osc->regmap;
 227         unsigned int mor;
 228
 229         regmap_read(regmap, AT91_CKGR_MOR, &mor);
 230
 231         if (!(mor & AT91_PMC_MOSCRCEN))
 232                 return;
 233
 234         regmap_update_bits(regmap, AT91_CKGR_MOR,
 235                            MOR_KEY_MASK | AT91_PMC_MOSCRCEN, AT91_PMC_KEY);
 236 }
 237
 238 static int clk_main_rc_osc_is_prepared(struct clk_hw *hw)
 239 {
 240         struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
 241         struct regmap *regmap = osc->regmap;
 242         unsigned int mor, status;
 243
 244         regmap_read(regmap, AT91_CKGR_MOR, &mor);
 245         regmap_read(regmap, AT91_PMC_SR, &status);
 246
 247         return (mor & AT91_PMC_MOSCRCEN) && (status & AT91_PMC_MOSCRCS);
 248 }
 249
 250 static unsigned long clk_main_rc_osc_recalc_rate(struct clk_hw *hw,
 251                                                  unsigned long parent_rate)
 252 {
 253         struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
 254
 255         return osc->frequency;
 256 }
 257
 258 static unsigned long clk_main_rc_osc_recalc_accuracy(struct clk_hw *hw,
 259                                                      unsigned long parent_acc)
 260 {
 261         struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
 262
 263         return osc->accuracy;
 264 }
 265
 266 static const struct clk_ops main_rc_osc_ops = {
 267         .prepare = clk_main_rc_osc_prepare,
 268         .unprepare = clk_main_rc_osc_unprepare,
 269         .is_prepared = clk_main_rc_osc_is_prepared,
 270         .recalc_rate = clk_main_rc_osc_recalc_rate,
 271         .recalc_accuracy = clk_main_rc_osc_recalc_accuracy,
 272 };
 273
 274 static struct clk * __init
 275 at91_clk_register_main_rc_osc(struct regmap *regmap,
 276                               const char *name,
 277                               u32 frequency, u32 accuracy)
 278 {
 279         struct clk_main_rc_osc *osc;
 280         struct clk *clk = NULL;
 281         struct clk_init_data init;
 282
 283         if (!name || !frequency)
 284                 return ERR_PTR(-EINVAL);
 285
 286         osc = kzalloc(sizeof(*osc), GFP_KERNEL);
 287         if (!osc)
 288                 return ERR_PTR(-ENOMEM);
 289
 290         init.name = name;
 291         init.ops = &main_rc_osc_ops;
 292         init.parent_names = NULL;
 293         init.num_parents = 0;
 294         init.flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED;
 295
 296         osc->hw.init = &init;
 297         osc->regmap = regmap;
 298         osc->frequency = frequency;
 299         osc->accuracy = accuracy;
 300
 301         clk = clk_register(NULL, &osc->hw);
 302         if (IS_ERR(clk))
 303                 kfree(osc);
 304
 305         return clk;
 306 }
 307
 308 static void __init of_at91sam9x5_clk_main_rc_osc_setup(struct device_node *np)
 309 {
 310         struct clk *clk;
 311         u32 frequency = 0;
 312         u32 accuracy = 0;
 313         const char *name = np->name;
 314         struct regmap *regmap;
 315
 316         of_property_read_string(np, "clock-output-names", &name);
 317         of_property_read_u32(np, "clock-frequency", &frequency);
 318         of_property_read_u32(np, "clock-accuracy", &accuracy);
 319
 320         regmap = syscon_node_to_regmap(of_get_parent(np));
 321         if (IS_ERR(regmap))
 322                 return;
 323
 324         clk = at91_clk_register_main_rc_osc(regmap, name, frequency, accuracy);
 325         if (IS_ERR(clk))
 326                 return;
 327
 328         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 329 }
 330 CLK_OF_DECLARE(at91sam9x5_clk_main_rc_osc, "atmel,at91sam9x5-clk-main-rc-osc",
 331                of_at91sam9x5_clk_main_rc_osc_setup);
 332
 333
 334 static int clk_main_probe_frequency(struct regmap *regmap)
 335 {
 336         unsigned long prep_time, timeout;
 337         unsigned int mcfr;
 338
 339         timeout = jiffies + usecs_to_jiffies(MAINFRDY_TIMEOUT);
 340         do {
 341                 prep_time = jiffies;
 342                 regmap_read(regmap, AT91_CKGR_MCFR, &mcfr);
 343                 if (mcfr & AT91_PMC_MAINRDY)
 344                         return 0;
 345                 usleep_range(MAINF_LOOP_MIN_WAIT, MAINF_LOOP_MAX_WAIT);
 346         } while (time_before(prep_time, timeout));
 347
 348         return -ETIMEDOUT;
 349 }
 350
 351 static unsigned long clk_main_recalc_rate(struct regmap *regmap,
 352                                           unsigned long parent_rate)
 353 {
 354         unsigned int mcfr;
 355
 356         if (parent_rate)
 357                 return parent_rate;
 358
 359         pr_warn("Main crystal frequency not set, using approximate value\n");
 360         regmap_read(regmap, AT91_CKGR_MCFR, &mcfr);
 361         if (!(mcfr & AT91_PMC_MAINRDY))
 362                 return 0;
 363
 364         return ((mcfr & AT91_PMC_MAINF) * SLOW_CLOCK_FREQ) / MAINF_DIV;
 365 }
 366
 367 static int clk_rm9200_main_prepare(struct clk_hw *hw)
 368 {
 369         struct clk_rm9200_main *clkmain = to_clk_rm9200_main(hw);
 370
 371         return clk_main_probe_frequency(clkmain->regmap);
 372 }
 373
 374 static int clk_rm9200_main_is_prepared(struct clk_hw *hw)
 375 {
 376         struct clk_rm9200_main *clkmain = to_clk_rm9200_main(hw);
 377         unsigned int status;
 378
 379         regmap_read(clkmain->regmap, AT91_CKGR_MCFR, &status);
 380
 381         return status & AT91_PMC_MAINRDY ? 1 : 0;
 382 }
 383
 384 static unsigned long clk_rm9200_main_recalc_rate(struct clk_hw *hw,
 385                                                  unsigned long parent_rate)
 386 {
 387         struct clk_rm9200_main *clkmain = to_clk_rm9200_main(hw);
 388
 389         return clk_main_recalc_rate(clkmain->regmap, parent_rate);
 390 }
 391
 392 static const struct clk_ops rm9200_main_ops = {
 393         .prepare = clk_rm9200_main_prepare,
 394         .is_prepared = clk_rm9200_main_is_prepared,
 395         .recalc_rate = clk_rm9200_main_recalc_rate,
 396 };
 397
 398 static struct clk * __init
 399 at91_clk_register_rm9200_main(struct regmap *regmap,
 400                               const char *name,
 401                               const char *parent_name)
 402 {
 403         struct clk_rm9200_main *clkmain;
 404         struct clk *clk = NULL;
 405         struct clk_init_data init;
 406
 407         if (!name)
 408                 return ERR_PTR(-EINVAL);
 409
 410         if (!parent_name)
 411                 return ERR_PTR(-EINVAL);
 412
 413         clkmain = kzalloc(sizeof(*clkmain), GFP_KERNEL);
 414         if (!clkmain)
 415                 return ERR_PTR(-ENOMEM);
 416
 417         init.name = name;
 418         init.ops = &rm9200_main_ops;
 419         init.parent_names = &parent_name;
 420         init.num_parents = 1;
 421         init.flags = 0;
 422
 423         clkmain->hw.init = &init;
 424         clkmain->regmap = regmap;
 425
 426         clk = clk_register(NULL, &clkmain->hw);
 427         if (IS_ERR(clk))
 428                 kfree(clkmain);
 429
 430         return clk;
 431 }
 432
 433 static void __init of_at91rm9200_clk_main_setup(struct device_node *np)
 434 {
 435         struct clk *clk;
 436         const char *parent_name;
 437         const char *name = np->name;
 438         struct regmap *regmap;
 439
 440         parent_name = of_clk_get_parent_name(np, 0);
 441         of_property_read_string(np, "clock-output-names", &name);
 442
 443         regmap = syscon_node_to_regmap(of_get_parent(np));
 444         if (IS_ERR(regmap))
 445                 return;
 446
 447         clk = at91_clk_register_rm9200_main(regmap, name, parent_name);
 448         if (IS_ERR(clk))
 449                 return;
 450
 451         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 452 }
 453 CLK_OF_DECLARE(at91rm9200_clk_main, "atmel,at91rm9200-clk-main",
 454                of_at91rm9200_clk_main_setup);
 455
 456 static inline bool clk_sam9x5_main_ready(struct regmap *regmap)
 457 {
 458         unsigned int status;
 459
 460         regmap_read(regmap, AT91_PMC_SR, &status);
 461
 462         return status & AT91_PMC_MOSCSELS ? 1 : 0;
 463 }
 464
 465 static int clk_sam9x5_main_prepare(struct clk_hw *hw)
 466 {
 467         struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
 468         struct regmap *regmap = clkmain->regmap;
 469
 470         while (!clk_sam9x5_main_ready(regmap))
 471                 cpu_relax();
 472
 473         return clk_main_probe_frequency(regmap);
 474 }
 475
 476 static int clk_sam9x5_main_is_prepared(struct clk_hw *hw)
 477 {
 478         struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
 479
 480         return clk_sam9x5_main_ready(clkmain->regmap);
 481 }
 482
 483 static unsigned long clk_sam9x5_main_recalc_rate(struct clk_hw *hw,
 484                                                  unsigned long parent_rate)
 485 {
 486         struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
 487
 488         return clk_main_recalc_rate(clkmain->regmap, parent_rate);
 489 }
 490
 491 static int clk_sam9x5_main_set_parent(struct clk_hw *hw, u8 index)
 492 {
 493         struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
 494         struct regmap *regmap = clkmain->regmap;
 495         unsigned int tmp;
 496
 497         if (index > 1)
 498                 return -EINVAL;
 499
 500         regmap_read(regmap, AT91_CKGR_MOR, &tmp);
 501         tmp &= ~MOR_KEY_MASK;
 502
 503         if (index && !(tmp & AT91_PMC_MOSCSEL))
 504                 regmap_write(regmap, AT91_CKGR_MOR, tmp | AT91_PMC_MOSCSEL);
 505         else if (!index && (tmp & AT91_PMC_MOSCSEL))
 506                 regmap_write(regmap, AT91_CKGR_MOR, tmp & ~AT91_PMC_MOSCSEL);
 507
 508         while (!clk_sam9x5_main_ready(regmap))
 509                 cpu_relax();
 510
 511         return 0;
 512 }
 513
 514 static u8 clk_sam9x5_main_get_parent(struct clk_hw *hw)
 515 {
 516         struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
 517         unsigned int status;
 518
 519         regmap_read(clkmain->regmap, AT91_CKGR_MOR, &status);
 520
 521         return status & AT91_PMC_MOSCEN ? 1 : 0;
 522 }
 523
 524 static const struct clk_ops sam9x5_main_ops = {
 525         .prepare = clk_sam9x5_main_prepare,
 526         .is_prepared = clk_sam9x5_main_is_prepared,
 527         .recalc_rate = clk_sam9x5_main_recalc_rate,
 528         .set_parent = clk_sam9x5_main_set_parent,
 529         .get_parent = clk_sam9x5_main_get_parent,
 530 };
 531
 532 static struct clk * __init
 533 at91_clk_register_sam9x5_main(struct regmap *regmap,
 534                               const char *name,
 535                               const char **parent_names,
 536                               int num_parents)
 537 {
 538         struct clk_sam9x5_main *clkmain;
 539         struct clk *clk = NULL;
 540         struct clk_init_data init;
 541         unsigned int status;
 542
 543         if (!name)
 544                 return ERR_PTR(-EINVAL);
 545
 546         if (!parent_names || !num_parents)
 547                 return ERR_PTR(-EINVAL);
 548
 549         clkmain = kzalloc(sizeof(*clkmain), GFP_KERNEL);
 550         if (!clkmain)
 551                 return ERR_PTR(-ENOMEM);
 552
 553         init.name = name;
 554         init.ops = &sam9x5_main_ops;
 555         init.parent_names = parent_names;
 556         init.num_parents = num_parents;
 557         init.flags = CLK_SET_PARENT_GATE;
 558
 559         clkmain->hw.init = &init;
 560         clkmain->regmap = regmap;
 561         regmap_read(clkmain->regmap, AT91_CKGR_MOR, &status);
 562         clkmain->parent = status & AT91_PMC_MOSCEN ? 1 : 0;
 563
 564         clk = clk_register(NULL, &clkmain->hw);
 565         if (IS_ERR(clk))
 566                 kfree(clkmain);
 567
 568         return clk;
 569 }
 570
 571 static void __init of_at91sam9x5_clk_main_setup(struct device_node *np)
 572 {
 573         struct clk *clk;
 574         const char *parent_names[2];
 575         int num_parents;
 576         const char *name = np->name;
 577         struct regmap *regmap;
 578
 579         num_parents = of_clk_get_parent_count(np);
 580         if (num_parents <= 0 || num_parents > 2)
 581                 return;
 582
 583         of_clk_parent_fill(np, parent_names, num_parents);
 584         regmap = syscon_node_to_regmap(of_get_parent(np));
 585         if (IS_ERR(regmap))
 586                 return;
 587
 588         of_property_read_string(np, "clock-output-names", &name);
 589
 590         clk = at91_clk_register_sam9x5_main(regmap, name, parent_names,
 591                                             num_parents);
 592         if (IS_ERR(clk))
 593                 return;
 594
 595         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 596 }
 597 CLK_OF_DECLARE(at91sam9x5_clk_main, "atmel,at91sam9x5-clk-main",
 598                of_at91sam9x5_clk_main_setup);