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 <asm/hardware.h>
  44 #include <asm/irq.h>
  45 #include <asm/io.h>
  46
  47 #include <asm/arch/regs-clock.h>
  48 #include <asm/arch/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         mutex_lock(&clocks_mutex);
 176         ret = (clk->set_rate)(clk, rate);
 177         mutex_unlock(&clocks_mutex);
 178
 179         return ret;
 180 }
 181
 182 struct clk *clk_get_parent(struct clk *clk)
 183 {
 184         return clk->parent;
 185 }
 186
 187 int clk_set_parent(struct clk *clk, struct clk *parent)
 188 {
 189         int ret = 0;
 190
 191         if (IS_ERR(clk))
 192                 return -EINVAL;
 193
 194         mutex_lock(&clocks_mutex);
 195
 196         if (clk->set_parent)
 197                 ret = (clk->set_parent)(clk, parent);
 198
 199         mutex_unlock(&clocks_mutex);
 200
 201         return ret;
 202 }
 203
 204 EXPORT_SYMBOL(clk_get);
 205 EXPORT_SYMBOL(clk_put);
 206 EXPORT_SYMBOL(clk_enable);
 207 EXPORT_SYMBOL(clk_disable);
 208 EXPORT_SYMBOL(clk_get_rate);
 209 EXPORT_SYMBOL(clk_round_rate);
 210 EXPORT_SYMBOL(clk_set_rate);
 211 EXPORT_SYMBOL(clk_get_parent);
 212 EXPORT_SYMBOL(clk_set_parent);
 213
 214 /* base clocks */
 215
 216 struct clk clk_xtal = {
 217         .name           = "xtal",
 218         .id             = -1,
 219         .rate           = 0,
 220         .parent         = NULL,
 221         .ctrlbit        = 0,
 222 };
 223
 224 struct clk clk_mpll = {
 225         .name           = "mpll",
 226         .id             = -1,
 227 };
 228
 229 struct clk clk_upll = {
 230         .name           = "upll",
 231         .id             = -1,
 232         .parent         = NULL,
 233         .ctrlbit        = 0,
 234 };
 235
 236 struct clk clk_f = {
 237         .name           = "fclk",
 238         .id             = -1,
 239         .rate           = 0,
 240         .parent         = &clk_mpll,
 241         .ctrlbit        = 0,
 242 };
 243
 244 struct clk clk_h = {
 245         .name           = "hclk",
 246         .id             = -1,
 247         .rate           = 0,
 248         .parent         = NULL,
 249         .ctrlbit        = 0,
 250 };
 251
 252 struct clk clk_p = {
 253         .name           = "pclk",
 254         .id             = -1,
 255         .rate           = 0,
 256         .parent         = NULL,
 257         .ctrlbit        = 0,
 258 };
 259
 260 struct clk clk_usb_bus = {
 261         .name           = "usb-bus",
 262         .id             = -1,
 263         .rate           = 0,
 264         .parent         = &clk_upll,
 265 };
 266
 267 /* clocks that could be registered by external code */
 268
 269 static int s3c24xx_dclk_enable(struct clk *clk, int enable)
 270 {
 271         unsigned long dclkcon = __raw_readl(S3C24XX_DCLKCON);
 272
 273         if (enable)
 274                 dclkcon |= clk->ctrlbit;
 275         else
 276                 dclkcon &= ~clk->ctrlbit;
 277
 278         __raw_writel(dclkcon, S3C24XX_DCLKCON);
 279
 280         return 0;
 281 }
 282
 283 static int s3c24xx_dclk_setparent(struct clk *clk, struct clk *parent)
 284 {
 285         unsigned long dclkcon;
 286         unsigned int uclk;
 287
 288         if (parent == &clk_upll)
 289                 uclk = 1;
 290         else if (parent == &clk_p)
 291                 uclk = 0;
 292         else
 293                 return -EINVAL;
 294
 295         clk->parent = parent;
 296
 297         dclkcon = __raw_readl(S3C24XX_DCLKCON);
 298
 299         if (clk->ctrlbit == S3C2410_DCLKCON_DCLK0EN) {
 300                 if (uclk)
 301                         dclkcon |= S3C2410_DCLKCON_DCLK0_UCLK;
 302                 else
 303                         dclkcon &= ~S3C2410_DCLKCON_DCLK0_UCLK;
 304         } else {
 305                 if (uclk)
 306                         dclkcon |= S3C2410_DCLKCON_DCLK1_UCLK;
 307                 else
 308                         dclkcon &= ~S3C2410_DCLKCON_DCLK1_UCLK;
 309         }
 310
 311         __raw_writel(dclkcon, S3C24XX_DCLKCON);
 312
 313         return 0;
 314 }
 315
 316
 317 static int s3c24xx_clkout_setparent(struct clk *clk, struct clk *parent)
 318 {
 319         unsigned long mask;
 320         unsigned long source;
 321
 322         /* calculate the MISCCR setting for the clock */
 323
 324         if (parent == &clk_xtal)
 325                 source = S3C2410_MISCCR_CLK0_MPLL;
 326         else if (parent == &clk_upll)
 327                 source = S3C2410_MISCCR_CLK0_UPLL;
 328         else if (parent == &clk_f)
 329                 source = S3C2410_MISCCR_CLK0_FCLK;
 330         else if (parent == &clk_h)
 331                 source = S3C2410_MISCCR_CLK0_HCLK;
 332         else if (parent == &clk_p)
 333                 source = S3C2410_MISCCR_CLK0_PCLK;
 334         else if (clk == &s3c24xx_clkout0 && parent == &s3c24xx_dclk0)
 335                 source = S3C2410_MISCCR_CLK0_DCLK0;
 336         else if (clk == &s3c24xx_clkout1 && parent == &s3c24xx_dclk1)
 337                 source = S3C2410_MISCCR_CLK0_DCLK0;
 338         else
 339                 return -EINVAL;
 340
 341         clk->parent = parent;
 342
 343         if (clk == &s3c24xx_dclk0)
 344                 mask = S3C2410_MISCCR_CLK0_MASK;
 345         else {
 346                 source <<= 4;
 347                 mask = S3C2410_MISCCR_CLK1_MASK;
 348         }
 349
 350         s3c2410_modify_misccr(mask, source);
 351         return 0;
 352 }
 353
 354 /* external clock definitions */
 355
 356 struct clk s3c24xx_dclk0 = {
 357         .name           = "dclk0",
 358         .id             = -1,
 359         .ctrlbit        = S3C2410_DCLKCON_DCLK0EN,
 360         .enable         = s3c24xx_dclk_enable,
 361         .set_parent     = s3c24xx_dclk_setparent,
 362 };
 363
 364 struct clk s3c24xx_dclk1 = {
 365         .name           = "dclk1",
 366         .id             = -1,
 367         .ctrlbit        = S3C2410_DCLKCON_DCLK0EN,
 368         .enable         = s3c24xx_dclk_enable,
 369         .set_parent     = s3c24xx_dclk_setparent,
 370 };
 371
 372 struct clk s3c24xx_clkout0 = {
 373         .name           = "clkout0",
 374         .id             = -1,
 375         .set_parent     = s3c24xx_clkout_setparent,
 376 };
 377
 378 struct clk s3c24xx_clkout1 = {
 379         .name           = "clkout1",
 380         .id             = -1,
 381         .set_parent     = s3c24xx_clkout_setparent,
 382 };
 383
 384 struct clk s3c24xx_uclk = {
 385         .name           = "uclk",
 386         .id             = -1,
 387 };
 388
 389 /* initialise the clock system */
 390
 391 int s3c24xx_register_clock(struct clk *clk)
 392 {
 393         clk->owner = THIS_MODULE;
 394
 395         if (clk->enable == NULL)
 396                 clk->enable = clk_null_enable;
 397
 398         /* add to the list of available clocks */
 399
 400         mutex_lock(&clocks_mutex);
 401         list_add(&clk->list, &clocks);
 402         mutex_unlock(&clocks_mutex);
 403
 404         return 0;
 405 }
 406
 407 int s3c24xx_register_clocks(struct clk **clks, int nr_clks)
 408 {
 409         int fails = 0;
 410
 411         for (; nr_clks > 0; nr_clks--, clks++) {
 412                 if (s3c24xx_register_clock(*clks) < 0)
 413                         fails++;
 414         }
 415
 416         return fails;
 417 }
 418
 419 /* initalise all the clocks */
 420
 421 int __init s3c24xx_setup_clocks(unsigned long xtal,
 422                                 unsigned long fclk,
 423                                 unsigned long hclk,
 424                                 unsigned long pclk)
 425 {
 426         printk(KERN_INFO "S3C24XX Clocks, (c) 2004 Simtec Electronics\n");
 427
 428         /* initialise the main system clocks */
 429
 430         clk_xtal.rate = xtal;
 431         clk_upll.rate = s3c2410_get_pll(__raw_readl(S3C2410_UPLLCON), xtal);
 432
 433         clk_mpll.rate = fclk;
 434         clk_h.rate = hclk;
 435         clk_p.rate = pclk;
 436         clk_f.rate = fclk;
 437
 438         /* assume uart clocks are correctly setup */
 439
 440         /* register our clocks */
 441
 442         if (s3c24xx_register_clock(&clk_xtal) < 0)
 443                 printk(KERN_ERR "failed to register master xtal\n");
 444
 445         if (s3c24xx_register_clock(&clk_mpll) < 0)
 446                 printk(KERN_ERR "failed to register mpll clock\n");
 447
 448         if (s3c24xx_register_clock(&clk_upll) < 0)
 449                 printk(KERN_ERR "failed to register upll clock\n");
 450
 451         if (s3c24xx_register_clock(&clk_f) < 0)
 452                 printk(KERN_ERR "failed to register cpu fclk\n");
 453
 454         if (s3c24xx_register_clock(&clk_h) < 0)
 455                 printk(KERN_ERR "failed to register cpu hclk\n");
 456
 457         if (s3c24xx_register_clock(&clk_p) < 0)
 458                 printk(KERN_ERR "failed to register cpu pclk\n");
 459
 460         return 0;
 461 }