arch/arm/plat-s3c24xx/clock.c

   1 /* linux/arch/arm/plat-s3c24xx/clock.c
   2  *
   3  * Copyright (c) 2004-2005 Simtec Electronics
   4  *      Ben Dooks <ben@simtec.co.uk>
   5  *
   6  * S3C24XX Core clock control support
   7  *
   8  * Based on, and code from linux/arch/arm/mach-versatile/clock.c
   9  **
  10  **  Copyright (C) 2004 ARM Limited.
  11  **  Written by Deep Blue Solutions Limited.
  12  *
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  27 */
  28
  29 #include <linux/init.h>
  30 #include <linux/module.h>
  31 #include <linux/kernel.h>
  32 #include <linux/list.h>
  33 #include <linux/errno.h>
  34 #include <linux/err.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/sysdev.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/ioport.h>
  39 #include <linux/clk.h>
  40 #include <linux/mutex.h>
  41 #include <linux/delay.h>
  42
  43 #include <mach/hardware.h>
  44 #include <asm/irq.h>
  45 #include <asm/io.h>
  46
  47 #include <mach/regs-clock.h>
  48 #include <mach/regs-gpio.h>
  49
  50 #include <asm/plat-s3c24xx/clock.h>
  51 #include <asm/plat-s3c24xx/cpu.h>
  52
  53 /* clock information */
  54
  55 static LIST_HEAD(clocks);
  56
  57 DEFINE_MUTEX(clocks_mutex);
  58
  59 /* enable and disable calls for use with the clk struct */
  60
  61 static int clk_null_enable(struct clk *clk, int enable)
  62 {
  63         return 0;
  64 }
  65
  66 /* Clock API calls */
  67
  68 struct clk *clk_get(struct device *dev, const char *id)
  69 {
  70         struct clk *p;
  71         struct clk *clk = ERR_PTR(-ENOENT);
  72         int idno;
  73
  74         if (dev == NULL || dev->bus != &platform_bus_type)
  75                 idno = -1;
  76         else
  77                 idno = to_platform_device(dev)->id;
  78
  79         mutex_lock(&clocks_mutex);
  80
  81         list_for_each_entry(p, &clocks, list) {
  82                 if (p->id == idno &&
  83                     strcmp(id, p->name) == 0 &&
  84                     try_module_get(p->owner)) {
  85                         clk = p;
  86                         break;
  87                 }
  88         }
  89
  90         /* check for the case where a device was supplied, but the
  91          * clock that was being searched for is not device specific */
  92
  93         if (IS_ERR(clk)) {
  94                 list_for_each_entry(p, &clocks, list) {
  95                         if (p->id == -1 && strcmp(id, p->name) == 0 &&
  96                             try_module_get(p->owner)) {
  97                                 clk = p;
  98                                 break;
  99                         }
 100                 }
 101         }
 102
 103         mutex_unlock(&clocks_mutex);
 104         return clk;
 105 }
 106
 107 void clk_put(struct clk *clk)
 108 {
 109         module_put(clk->owner);
 110 }
 111
 112 int clk_enable(struct clk *clk)
 113 {
 114         if (IS_ERR(clk) || clk == NULL)
 115                 return -EINVAL;
 116
 117         clk_enable(clk->parent);
 118
 119         mutex_lock(&clocks_mutex);
 120
 121         if ((clk->usage++) == 0)
 122                 (clk->enable)(clk, 1);
 123
 124         mutex_unlock(&clocks_mutex);
 125         return 0;
 126 }
 127
 128 void clk_disable(struct clk *clk)
 129 {
 130         if (IS_ERR(clk) || clk == NULL)
 131                 return;
 132
 133         mutex_lock(&clocks_mutex);
 134
 135         if ((--clk->usage) == 0)
 136                 (clk->enable)(clk, 0);
 137
 138         mutex_unlock(&clocks_mutex);
 139         clk_disable(clk->parent);
 140 }
 141
 142
 143 unsigned long clk_get_rate(struct clk *clk)
 144 {
 145         if (IS_ERR(clk))
 146                 return 0;
 147
 148         if (clk->rate != 0)
 149                 return clk->rate;
 150
 151         if (clk->get_rate != NULL)
 152                 return (clk->get_rate)(clk);
 153
 154         if (clk->parent != NULL)
 155                 return clk_get_rate(clk->parent);
 156
 157         return clk->rate;
 158 }
 159
 160 long clk_round_rate(struct clk *clk, unsigned long rate)
 161 {
 162         if (!IS_ERR(clk) && clk->round_rate)
 163                 return (clk->round_rate)(clk, rate);
 164
 165         return rate;
 166 }
 167
 168 int clk_set_rate(struct clk *clk, unsigned long rate)
 169 {
 170         int ret;
 171
 172         if (IS_ERR(clk))
 173                 return -EINVAL;
 174
 175         /* We do not default just do a clk->rate = rate as
 176          * the clock may have been made this way by choice.
 177          */
 178
 179         WARN_ON(clk->set_rate == NULL);
 180
 181         if (clk->set_rate == NULL)
 182                 return -EINVAL;
 183
 184         mutex_lock(&clocks_mutex);
 185         ret = (clk->set_rate)(clk, rate);
 186         mutex_unlock(&clocks_mutex);
 187
 188         return ret;
 189 }
 190
 191 struct clk *clk_get_parent(struct clk *clk)
 192 {
 193         return clk->parent;
 194 }
 195
 196 int clk_set_parent(struct clk *clk, struct clk *parent)
 197 {
 198         int ret = 0;
 199
 200         if (IS_ERR(clk))
 201                 return -EINVAL;
 202
 203         mutex_lock(&clocks_mutex);
 204
 205         if (clk->set_parent)
 206                 ret = (clk->set_parent)(clk, parent);
 207
 208         mutex_unlock(&clocks_mutex);
 209
 210         return ret;
 211 }
 212
 213 EXPORT_SYMBOL(clk_get);
 214 EXPORT_SYMBOL(clk_put);
 215 EXPORT_SYMBOL(clk_enable);
 216 EXPORT_SYMBOL(clk_disable);
 217 EXPORT_SYMBOL(clk_get_rate);
 218 EXPORT_SYMBOL(clk_round_rate);
 219 EXPORT_SYMBOL(clk_set_rate);
 220 EXPORT_SYMBOL(clk_get_parent);
 221 EXPORT_SYMBOL(clk_set_parent);
 222
 223 /* base clocks */
 224
 225 static int clk_default_setrate(struct clk *clk, unsigned long rate)
 226 {
 227         clk->rate = rate;
 228         return 0;
 229 }
 230
 231 struct clk clk_xtal = {
 232         .name           = "xtal",
 233         .id             = -1,
 234         .rate           = 0,
 235         .parent         = NULL,
 236         .ctrlbit        = 0,
 237 };
 238
 239 struct clk clk_mpll = {
 240         .name           = "mpll",
 241         .id             = -1,
 242         .set_rate       = clk_default_setrate,
 243 };
 244
 245 struct clk clk_upll = {
 246         .name           = "upll",
 247         .id             = -1,
 248         .parent         = NULL,
 249         .ctrlbit        = 0,
 250 };
 251
 252 struct clk clk_f = {
 253         .name           = "fclk",
 254         .id             = -1,
 255         .rate           = 0,
 256         .parent         = &clk_mpll,
 257         .ctrlbit        = 0,
 258         .set_rate       = clk_default_setrate,
 259 };
 260
 261 struct clk clk_h = {
 262         .name           = "hclk",
 263         .id             = -1,
 264         .rate           = 0,
 265         .parent         = NULL,
 266         .ctrlbit        = 0,
 267         .set_rate       = clk_default_setrate,
 268 };
 269
 270 struct clk clk_p = {
 271         .name           = "pclk",
 272         .id             = -1,
 273         .rate           = 0,
 274         .parent         = NULL,
 275         .ctrlbit        = 0,
 276         .set_rate       = clk_default_setrate,
 277 };
 278
 279 struct clk clk_usb_bus = {
 280         .name           = "usb-bus",
 281         .id             = -1,
 282         .rate           = 0,
 283         .parent         = &clk_upll,
 284 };
 285
 286 /* clocks that could be registered by external code */
 287
 288 static int s3c24xx_dclk_enable(struct clk *clk, int enable)
 289 {
 290         unsigned long dclkcon = __raw_readl(S3C24XX_DCLKCON);
 291
 292         if (enable)
 293                 dclkcon |= clk->ctrlbit;
 294         else
 295                 dclkcon &= ~clk->ctrlbit;
 296
 297         __raw_writel(dclkcon, S3C24XX_DCLKCON);
 298
 299         return 0;
 300 }
 301
 302 static int s3c24xx_dclk_setparent(struct clk *clk, struct clk *parent)
 303 {
 304         unsigned long dclkcon;
 305         unsigned int uclk;
 306
 307         if (parent == &clk_upll)
 308                 uclk = 1;
 309         else if (parent == &clk_p)
 310                 uclk = 0;
 311         else
 312                 return -EINVAL;
 313
 314         clk->parent = parent;
 315
 316         dclkcon = __raw_readl(S3C24XX_DCLKCON);
 317
 318         if (clk->ctrlbit == S3C2410_DCLKCON_DCLK0EN) {
 319                 if (uclk)
 320                         dclkcon |= S3C2410_DCLKCON_DCLK0_UCLK;
 321                 else
 322                         dclkcon &= ~S3C2410_DCLKCON_DCLK0_UCLK;
 323         } else {
 324                 if (uclk)
 325                         dclkcon |= S3C2410_DCLKCON_DCLK1_UCLK;
 326                 else
 327                         dclkcon &= ~S3C2410_DCLKCON_DCLK1_UCLK;
 328         }
 329
 330         __raw_writel(dclkcon, S3C24XX_DCLKCON);
 331
 332         return 0;
 333 }
 334
 335 static unsigned long s3c24xx_calc_div(struct clk *clk, unsigned long rate)
 336 {
 337         unsigned long div;
 338
 339         if ((rate == 0) || !clk->parent)
 340                 return 0;
 341
 342         div = clk_get_rate(clk->parent) / rate;
 343         if (div < 2)
 344                 div = 2;
 345         else if (div > 16)
 346                 div = 16;
 347
 348         return div;
 349 }
 350
 351 static unsigned long s3c24xx_round_dclk_rate(struct clk *clk,
 352         unsigned long rate)
 353 {
 354         unsigned long div = s3c24xx_calc_div(clk, rate);
 355
 356         if (div == 0)
 357                 return 0;
 358
 359         return clk_get_rate(clk->parent) / div;
 360 }
 361
 362 static int s3c24xx_set_dclk_rate(struct clk *clk, unsigned long rate)
 363 {
 364         unsigned long mask, data, div = s3c24xx_calc_div(clk, rate);
 365
 366         if (div == 0)
 367                 return -EINVAL;
 368
 369         if (clk == &s3c24xx_dclk0) {
 370                 mask = S3C2410_DCLKCON_DCLK0_DIV_MASK |
 371                         S3C2410_DCLKCON_DCLK0_CMP_MASK;
 372                 data = S3C2410_DCLKCON_DCLK0_DIV(div) |
 373                         S3C2410_DCLKCON_DCLK0_CMP((div + 1) / 2);
 374         } else if (clk == &s3c24xx_dclk1) {
 375                 mask = S3C2410_DCLKCON_DCLK1_DIV_MASK |
 376                         S3C2410_DCLKCON_DCLK1_CMP_MASK;
 377                 data = S3C2410_DCLKCON_DCLK1_DIV(div) |
 378                         S3C2410_DCLKCON_DCLK1_CMP((div + 1) / 2);
 379         } else
 380                 return -EINVAL;
 381
 382         clk->rate = clk_get_rate(clk->parent) / div;
 383         __raw_writel(((__raw_readl(S3C24XX_DCLKCON) & ~mask) | data),
 384                 S3C24XX_DCLKCON);
 385         return clk->rate;
 386 }
 387
 388 static int s3c24xx_clkout_setparent(struct clk *clk, struct clk *parent)
 389 {
 390         unsigned long mask;
 391         unsigned long source;
 392
 393         /* calculate the MISCCR setting for the clock */
 394
 395         if (parent == &clk_xtal)
 396                 source = S3C2410_MISCCR_CLK0_MPLL;
 397         else if (parent == &clk_upll)
 398                 source = S3C2410_MISCCR_CLK0_UPLL;
 399         else if (parent == &clk_f)
 400                 source = S3C2410_MISCCR_CLK0_FCLK;
 401         else if (parent == &clk_h)
 402                 source = S3C2410_MISCCR_CLK0_HCLK;
 403         else if (parent == &clk_p)
 404                 source = S3C2410_MISCCR_CLK0_PCLK;
 405         else if (clk == &s3c24xx_clkout0 && parent == &s3c24xx_dclk0)
 406                 source = S3C2410_MISCCR_CLK0_DCLK0;
 407         else if (clk == &s3c24xx_clkout1 && parent == &s3c24xx_dclk1)
 408                 source = S3C2410_MISCCR_CLK0_DCLK0;
 409         else
 410                 return -EINVAL;
 411
 412         clk->parent = parent;
 413
 414         if (clk == &s3c24xx_clkout0)
 415                 mask = S3C2410_MISCCR_CLK0_MASK;
 416         else {
 417                 source <<= 4;
 418                 mask = S3C2410_MISCCR_CLK1_MASK;
 419         }
 420
 421         s3c2410_modify_misccr(mask, source);
 422         return 0;
 423 }
 424
 425 /* external clock definitions */
 426
 427 struct clk s3c24xx_dclk0 = {
 428         .name           = "dclk0",
 429         .id             = -1,
 430         .ctrlbit        = S3C2410_DCLKCON_DCLK0EN,
 431         .enable         = s3c24xx_dclk_enable,
 432         .set_parent     = s3c24xx_dclk_setparent,
 433         .set_rate       = s3c24xx_set_dclk_rate,
 434         .round_rate     = s3c24xx_round_dclk_rate,
 435 };
 436
 437 struct clk s3c24xx_dclk1 = {
 438         .name           = "dclk1",
 439         .id             = -1,
 440         .ctrlbit        = S3C2410_DCLKCON_DCLK1EN,
 441         .enable         = s3c24xx_dclk_enable,
 442         .set_parent     = s3c24xx_dclk_setparent,
 443         .set_rate       = s3c24xx_set_dclk_rate,
 444         .round_rate     = s3c24xx_round_dclk_rate,
 445 };
 446
 447 struct clk s3c24xx_clkout0 = {
 448         .name           = "clkout0",
 449         .id             = -1,
 450         .set_parent     = s3c24xx_clkout_setparent,
 451 };
 452
 453 struct clk s3c24xx_clkout1 = {
 454         .name           = "clkout1",
 455         .id             = -1,
 456         .set_parent     = s3c24xx_clkout_setparent,
 457 };
 458
 459 struct clk s3c24xx_uclk = {
 460         .name           = "uclk",
 461         .id             = -1,
 462 };
 463
 464 /* initialise the clock system */
 465
 466 int s3c24xx_register_clock(struct clk *clk)
 467 {
 468         clk->owner = THIS_MODULE;
 469
 470         if (clk->enable == NULL)
 471                 clk->enable = clk_null_enable;
 472
 473         /* add to the list of available clocks */
 474
 475         mutex_lock(&clocks_mutex);
 476         list_add(&clk->list, &clocks);
 477         mutex_unlock(&clocks_mutex);
 478
 479         return 0;
 480 }
 481
 482 int s3c24xx_register_clocks(struct clk **clks, int nr_clks)
 483 {
 484         int fails = 0;
 485
 486         for (; nr_clks > 0; nr_clks--, clks++) {
 487                 if (s3c24xx_register_clock(*clks) < 0)
 488                         fails++;
 489         }
 490
 491         return fails;
 492 }
 493
 494 /* initalise all the clocks */
 495
 496 int __init s3c24xx_setup_clocks(unsigned long xtal,
 497                                 unsigned long fclk,
 498                                 unsigned long hclk,
 499                                 unsigned long pclk)
 500 {
 501         printk(KERN_INFO "S3C24XX Clocks, (c) 2004 Simtec Electronics\n");
 502
 503         /* initialise the main system clocks */
 504
 505         clk_xtal.rate = xtal;
 506         clk_upll.rate = s3c2410_get_pll(__raw_readl(S3C2410_UPLLCON), xtal);
 507
 508         clk_mpll.rate = fclk;
 509         clk_h.rate = hclk;
 510         clk_p.rate = pclk;
 511         clk_f.rate = fclk;
 512
 513         /* assume uart clocks are correctly setup */
 514
 515         /* register our clocks */
 516
 517         if (s3c24xx_register_clock(&clk_xtal) < 0)
 518                 printk(KERN_ERR "failed to register master xtal\n");
 519
 520         if (s3c24xx_register_clock(&clk_mpll) < 0)
 521                 printk(KERN_ERR "failed to register mpll clock\n");
 522
 523         if (s3c24xx_register_clock(&clk_upll) < 0)
 524                 printk(KERN_ERR "failed to register upll clock\n");
 525
 526         if (s3c24xx_register_clock(&clk_f) < 0)
 527                 printk(KERN_ERR "failed to register cpu fclk\n");
 528
 529         if (s3c24xx_register_clock(&clk_h) < 0)
 530                 printk(KERN_ERR "failed to register cpu hclk\n");
 531
 532         if (s3c24xx_register_clock(&clk_p) < 0)
 533                 printk(KERN_ERR "failed to register cpu pclk\n");
 534
 535         return 0;
 536 }