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   1 /* linux/arch/arm/mach-s3c2410/clock.c
   2  *
   3  * Copyright (c) 2004-2005 Simtec Electronics
   4  *      Ben Dooks <ben@simtec.co.uk>
   5  *
   6  * S3C2410 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 "clock.h"
  51 #include "cpu.h"
  52
  53 /* clock information */
  54
  55 static LIST_HEAD(clocks);
  56
  57 DEFINE_MUTEX(clocks_mutex);
  58
  59 /* old functions */
  60
  61 void inline s3c24xx_clk_enable(unsigned int clocks, unsigned int enable)
  62 {
  63         unsigned long clkcon;
  64
  65         clkcon = __raw_readl(S3C2410_CLKCON);
  66
  67         if (enable)
  68                 clkcon |= clocks;
  69         else
  70                 clkcon &= ~clocks;
  71
  72         /* ensure none of the special function bits set */
  73         clkcon &= ~(S3C2410_CLKCON_IDLE|S3C2410_CLKCON_POWER);
  74
  75         __raw_writel(clkcon, S3C2410_CLKCON);
  76 }
  77
  78 /* enable and disable calls for use with the clk struct */
  79
  80 static int clk_null_enable(struct clk *clk, int enable)
  81 {
  82         return 0;
  83 }
  84
  85 int s3c24xx_clkcon_enable(struct clk *clk, int enable)
  86 {
  87         s3c24xx_clk_enable(clk->ctrlbit, enable);
  88         return 0;
  89 }
  90
  91 /* Clock API calls */
  92
  93 struct clk *clk_get(struct device *dev, const char *id)
  94 {
  95         struct clk *p;
  96         struct clk *clk = ERR_PTR(-ENOENT);
  97         int idno;
  98
  99         if (dev == NULL || dev->bus != &platform_bus_type)
 100                 idno = -1;
 101         else
 102                 idno = to_platform_device(dev)->id;
 103
 104         mutex_lock(&clocks_mutex);
 105
 106         list_for_each_entry(p, &clocks, list) {
 107                 if (p->id == idno &&
 108                     strcmp(id, p->name) == 0 &&
 109                     try_module_get(p->owner)) {
 110                         clk = p;
 111                         break;
 112                 }
 113         }
 114
 115         /* check for the case where a device was supplied, but the
 116          * clock that was being searched for is not device specific */
 117
 118         if (IS_ERR(clk)) {
 119                 list_for_each_entry(p, &clocks, list) {
 120                         if (p->id == -1 && strcmp(id, p->name) == 0 &&
 121                             try_module_get(p->owner)) {
 122                                 clk = p;
 123                                 break;
 124                         }
 125                 }
 126         }
 127
 128         mutex_unlock(&clocks_mutex);
 129         return clk;
 130 }
 131
 132 void clk_put(struct clk *clk)
 133 {
 134         module_put(clk->owner);
 135 }
 136
 137 int clk_enable(struct clk *clk)
 138 {
 139         if (IS_ERR(clk) || clk == NULL)
 140                 return -EINVAL;
 141
 142         clk_enable(clk->parent);
 143
 144         mutex_lock(&clocks_mutex);
 145
 146         if ((clk->usage++) == 0)
 147                 (clk->enable)(clk, 1);
 148
 149         mutex_unlock(&clocks_mutex);
 150         return 0;
 151 }
 152
 153 void clk_disable(struct clk *clk)
 154 {
 155         if (IS_ERR(clk) || clk == NULL)
 156                 return;
 157
 158         mutex_lock(&clocks_mutex);
 159
 160         if ((--clk->usage) == 0)
 161                 (clk->enable)(clk, 0);
 162
 163         mutex_unlock(&clocks_mutex);
 164         clk_disable(clk->parent);
 165 }
 166
 167
 168 unsigned long clk_get_rate(struct clk *clk)
 169 {
 170         if (IS_ERR(clk))
 171                 return 0;
 172
 173         if (clk->rate != 0)
 174                 return clk->rate;
 175
 176         while (clk->parent != NULL && clk->rate == 0)
 177                 clk = clk->parent;
 178
 179         return clk->rate;
 180 }
 181
 182 long clk_round_rate(struct clk *clk, unsigned long rate)
 183 {
 184         if (!IS_ERR(clk) && clk->round_rate)
 185                 return (clk->round_rate)(clk, rate);
 186
 187         return rate;
 188 }
 189
 190 int clk_set_rate(struct clk *clk, unsigned long rate)
 191 {
 192         int ret;
 193
 194         if (IS_ERR(clk))
 195                 return -EINVAL;
 196
 197         mutex_lock(&clocks_mutex);
 198         ret = (clk->set_rate)(clk, rate);
 199         mutex_unlock(&clocks_mutex);
 200
 201         return ret;
 202 }
 203
 204 struct clk *clk_get_parent(struct clk *clk)
 205 {
 206         return clk->parent;
 207 }
 208
 209 int clk_set_parent(struct clk *clk, struct clk *parent)
 210 {
 211         int ret = 0;
 212
 213         if (IS_ERR(clk))
 214                 return -EINVAL;
 215
 216         mutex_lock(&clocks_mutex);
 217
 218         if (clk->set_parent)
 219                 ret = (clk->set_parent)(clk, parent);
 220
 221         mutex_unlock(&clocks_mutex);
 222
 223         return ret;
 224 }
 225
 226 EXPORT_SYMBOL(clk_get);
 227 EXPORT_SYMBOL(clk_put);
 228 EXPORT_SYMBOL(clk_enable);
 229 EXPORT_SYMBOL(clk_disable);
 230 EXPORT_SYMBOL(clk_get_rate);
 231 EXPORT_SYMBOL(clk_round_rate);
 232 EXPORT_SYMBOL(clk_set_rate);
 233 EXPORT_SYMBOL(clk_get_parent);
 234 EXPORT_SYMBOL(clk_set_parent);
 235
 236 /* base clock enable */
 237
 238 static int s3c24xx_upll_enable(struct clk *clk, int enable)
 239 {
 240         unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
 241         unsigned long orig = clkslow;
 242
 243         if (enable)
 244                 clkslow &= ~S3C2410_CLKSLOW_UCLK_OFF;
 245         else
 246                 clkslow |= S3C2410_CLKSLOW_UCLK_OFF;
 247
 248         __raw_writel(clkslow, S3C2410_CLKSLOW);
 249
 250         /* if we started the UPLL, then allow to settle */
 251
 252         if (enable && !(orig & S3C2410_CLKSLOW_UCLK_OFF))
 253                 udelay(200);
 254
 255         return 0;
 256 }
 257
 258 /* base clocks */
 259
 260 static struct clk clk_xtal = {
 261         .name           = "xtal",
 262         .id             = -1,
 263         .rate           = 0,
 264         .parent         = NULL,
 265         .ctrlbit        = 0,
 266 };
 267
 268 static struct clk clk_upll = {
 269         .name           = "upll",
 270         .id             = -1,
 271         .parent         = NULL,
 272         .enable         = s3c24xx_upll_enable,
 273         .ctrlbit        = 0,
 274 };
 275
 276 static struct clk clk_f = {
 277         .name           = "fclk",
 278         .id             = -1,
 279         .rate           = 0,
 280         .parent         = NULL,
 281         .ctrlbit        = 0,
 282 };
 283
 284 static struct clk clk_h = {
 285         .name           = "hclk",
 286         .id             = -1,
 287         .rate           = 0,
 288         .parent         = NULL,
 289         .ctrlbit        = 0,
 290 };
 291
 292 static struct clk clk_p = {
 293         .name           = "pclk",
 294         .id             = -1,
 295         .rate           = 0,
 296         .parent         = NULL,
 297         .ctrlbit        = 0,
 298 };
 299
 300 struct clk clk_usb_bus = {
 301         .name           = "usb-bus",
 302         .id             = -1,
 303         .rate           = 0,
 304         .parent         = &clk_upll,
 305 };
 306
 307 /* clocks that could be registered by external code */
 308
 309 static int s3c24xx_dclk_enable(struct clk *clk, int enable)
 310 {
 311         unsigned long dclkcon = __raw_readl(S3C2410_DCLKCON);
 312
 313         if (enable)
 314                 dclkcon |= clk->ctrlbit;
 315         else
 316                 dclkcon &= ~clk->ctrlbit;
 317
 318         __raw_writel(dclkcon, S3C2410_DCLKCON);
 319
 320         return 0;
 321 }
 322
 323 static int s3c24xx_dclk_setparent(struct clk *clk, struct clk *parent)
 324 {
 325         unsigned long dclkcon;
 326         unsigned int uclk;
 327
 328         if (parent == &clk_upll)
 329                 uclk = 1;
 330         else if (parent == &clk_p)
 331                 uclk = 0;
 332         else
 333                 return -EINVAL;
 334
 335         clk->parent = parent;
 336
 337         dclkcon = __raw_readl(S3C2410_DCLKCON);
 338
 339         if (clk->ctrlbit == S3C2410_DCLKCON_DCLK0EN) {
 340                 if (uclk)
 341                         dclkcon |= S3C2410_DCLKCON_DCLK0_UCLK;
 342                 else
 343                         dclkcon &= ~S3C2410_DCLKCON_DCLK0_UCLK;
 344         } else {
 345                 if (uclk)
 346                         dclkcon |= S3C2410_DCLKCON_DCLK1_UCLK;
 347                 else
 348                         dclkcon &= ~S3C2410_DCLKCON_DCLK1_UCLK;
 349         }
 350
 351         __raw_writel(dclkcon, S3C2410_DCLKCON);
 352
 353         return 0;
 354 }
 355
 356
 357 static int s3c24xx_clkout_setparent(struct clk *clk, struct clk *parent)
 358 {
 359         unsigned long mask;
 360         unsigned long source;
 361
 362         /* calculate the MISCCR setting for the clock */
 363
 364         if (parent == &clk_xtal)
 365                 source = S3C2410_MISCCR_CLK0_MPLL;
 366         else if (parent == &clk_upll)
 367                 source = S3C2410_MISCCR_CLK0_UPLL;
 368         else if (parent == &clk_f)
 369                 source = S3C2410_MISCCR_CLK0_FCLK;
 370         else if (parent == &clk_p)
 371                 source = S3C2410_MISCCR_CLK0_PCLK;
 372         else if (clk == &s3c24xx_clkout0 && parent == &s3c24xx_dclk0)
 373                 source = S3C2410_MISCCR_CLK0_DCLK0;
 374         else if (clk == &s3c24xx_clkout1 && parent == &s3c24xx_dclk1)
 375                 source = S3C2410_MISCCR_CLK0_DCLK0;
 376         else
 377                 return -EINVAL;
 378
 379         if (clk == &s3c24xx_dclk0)
 380                 mask = S3C2410_MISCCR_CLK0_MASK;
 381         else {
 382                 source <<= 4;
 383                 mask = S3C2410_MISCCR_CLK1_MASK;
 384         }
 385
 386         s3c2410_modify_misccr(mask, source);
 387         return 0;
 388 }
 389
 390 /* external clock definitions */
 391
 392 struct clk s3c24xx_dclk0 = {
 393         .name           = "dclk0",
 394         .id             = -1,
 395         .ctrlbit        = S3C2410_DCLKCON_DCLK0EN,
 396         .enable         = s3c24xx_dclk_enable,
 397         .set_parent     = s3c24xx_dclk_setparent,
 398 };
 399
 400 struct clk s3c24xx_dclk1 = {
 401         .name           = "dclk1",
 402         .id             = -1,
 403         .ctrlbit        = S3C2410_DCLKCON_DCLK0EN,
 404         .enable         = s3c24xx_dclk_enable,
 405         .set_parent     = s3c24xx_dclk_setparent,
 406 };
 407
 408 struct clk s3c24xx_clkout0 = {
 409         .name           = "clkout0",
 410         .id             = -1,
 411         .set_parent     = s3c24xx_clkout_setparent,
 412 };
 413
 414 struct clk s3c24xx_clkout1 = {
 415         .name           = "clkout1",
 416         .id             = -1,
 417         .set_parent     = s3c24xx_clkout_setparent,
 418 };
 419
 420 struct clk s3c24xx_uclk = {
 421         .name           = "uclk",
 422         .id             = -1,
 423 };
 424
 425
 426 /* standard clock definitions */
 427
 428 static struct clk init_clocks[] = {
 429         {
 430                 .name           = "nand",
 431                 .id             = -1,
 432                 .parent         = &clk_h,
 433                 .enable         = s3c24xx_clkcon_enable,
 434                 .ctrlbit        = S3C2410_CLKCON_NAND,
 435         }, {
 436                 .name           = "lcd",
 437                 .id             = -1,
 438                 .parent         = &clk_h,
 439                 .enable         = s3c24xx_clkcon_enable,
 440                 .ctrlbit        = S3C2410_CLKCON_LCDC,
 441         }, {
 442                 .name           = "usb-host",
 443                 .id             = -1,
 444                 .parent         = &clk_h,
 445                 .enable         = s3c24xx_clkcon_enable,
 446                 .ctrlbit        = S3C2410_CLKCON_USBH,
 447         }, {
 448                 .name           = "usb-device",
 449                 .id             = -1,
 450                 .parent         = &clk_h,
 451                 .enable         = s3c24xx_clkcon_enable,
 452                 .ctrlbit        = S3C2410_CLKCON_USBD,
 453         }, {
 454                 .name           = "timers",
 455                 .id             = -1,
 456                 .parent         = &clk_p,
 457                 .enable         = s3c24xx_clkcon_enable,
 458                 .ctrlbit        = S3C2410_CLKCON_PWMT,
 459         }, {
 460                 .name           = "sdi",
 461                 .id             = -1,
 462                 .parent         = &clk_p,
 463                 .enable         = s3c24xx_clkcon_enable,
 464                 .ctrlbit        = S3C2410_CLKCON_SDI,
 465         }, {
 466                 .name           = "uart",
 467                 .id             = 0,
 468                 .parent         = &clk_p,
 469                 .enable         = s3c24xx_clkcon_enable,
 470                 .ctrlbit        = S3C2410_CLKCON_UART0,
 471         }, {
 472                 .name           = "uart",
 473                 .id             = 1,
 474                 .parent         = &clk_p,
 475                 .enable         = s3c24xx_clkcon_enable,
 476                 .ctrlbit        = S3C2410_CLKCON_UART1,
 477         }, {
 478                 .name           = "uart",
 479                 .id             = 2,
 480                 .parent         = &clk_p,
 481                 .enable         = s3c24xx_clkcon_enable,
 482                 .ctrlbit        = S3C2410_CLKCON_UART2,
 483         }, {
 484                 .name           = "gpio",
 485                 .id             = -1,
 486                 .parent         = &clk_p,
 487                 .enable         = s3c24xx_clkcon_enable,
 488                 .ctrlbit        = S3C2410_CLKCON_GPIO,
 489         }, {
 490                 .name           = "rtc",
 491                 .id             = -1,
 492                 .parent         = &clk_p,
 493                 .enable         = s3c24xx_clkcon_enable,
 494                 .ctrlbit        = S3C2410_CLKCON_RTC,
 495         }, {
 496                 .name           = "adc",
 497                 .id             = -1,
 498                 .parent         = &clk_p,
 499                 .enable         = s3c24xx_clkcon_enable,
 500                 .ctrlbit        = S3C2410_CLKCON_ADC,
 501         }, {
 502                 .name           = "i2c",
 503                 .id             = -1,
 504                 .parent         = &clk_p,
 505                 .enable         = s3c24xx_clkcon_enable,
 506                 .ctrlbit        = S3C2410_CLKCON_IIC,
 507         }, {
 508                 .name           = "iis",
 509                 .id             = -1,
 510                 .parent         = &clk_p,
 511                 .enable         = s3c24xx_clkcon_enable,
 512                 .ctrlbit        = S3C2410_CLKCON_IIS,
 513         }, {
 514                 .name           = "spi",
 515                 .id             = -1,
 516                 .parent         = &clk_p,
 517                 .enable         = s3c24xx_clkcon_enable,
 518                 .ctrlbit        = S3C2410_CLKCON_SPI,
 519         }, {
 520                 .name           = "watchdog",
 521                 .id             = -1,
 522                 .parent         = &clk_p,
 523                 .ctrlbit        = 0,
 524         }
 525 };
 526
 527 /* initialise the clock system */
 528
 529 int s3c24xx_register_clock(struct clk *clk)
 530 {
 531         clk->owner = THIS_MODULE;
 532
 533         if (clk->enable == NULL)
 534                 clk->enable = clk_null_enable;
 535
 536         /* if this is a standard clock, set the usage state */
 537
 538         if (clk->ctrlbit && clk->enable == s3c24xx_clkcon_enable) {
 539                 unsigned long clkcon = __raw_readl(S3C2410_CLKCON);
 540
 541                 clk->usage = (clkcon & clk->ctrlbit) ? 1 : 0;
 542         }
 543
 544         /* add to the list of available clocks */
 545
 546         mutex_lock(&clocks_mutex);
 547         list_add(&clk->list, &clocks);
 548         mutex_unlock(&clocks_mutex);
 549
 550         return 0;
 551 }
 552
 553 /* initalise all the clocks */
 554
 555 int __init s3c24xx_setup_clocks(unsigned long xtal,
 556                                 unsigned long fclk,
 557                                 unsigned long hclk,
 558                                 unsigned long pclk)
 559 {
 560         unsigned long upllcon = __raw_readl(S3C2410_UPLLCON);
 561         unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
 562         struct clk *clkp = init_clocks;
 563         int ptr;
 564         int ret;
 565
 566         printk(KERN_INFO "S3C2410 Clocks, (c) 2004 Simtec Electronics\n");
 567
 568         /* initialise the main system clocks */
 569
 570         clk_xtal.rate = xtal;
 571         clk_upll.rate = s3c2410_get_pll(upllcon, xtal);
 572
 573         clk_h.rate = hclk;
 574         clk_p.rate = pclk;
 575         clk_f.rate = fclk;
 576
 577         /* We must be careful disabling the clocks we are not intending to
 578          * be using at boot time, as subsytems such as the LCD which do
 579          * their own DMA requests to the bus can cause the system to lockup
 580          * if they where in the middle of requesting bus access.
 581          *
 582          * Disabling the LCD clock if the LCD is active is very dangerous,
 583          * and therefore the bootloader should be  careful to not enable
 584          * the LCD clock if it is not needed.
 585         */
 586
 587         mutex_lock(&clocks_mutex);
 588
 589         s3c24xx_clk_enable(S3C2410_CLKCON_NAND, 0);
 590         s3c24xx_clk_enable(S3C2410_CLKCON_USBH, 0);
 591         s3c24xx_clk_enable(S3C2410_CLKCON_USBD, 0);
 592         s3c24xx_clk_enable(S3C2410_CLKCON_ADC, 0);
 593         s3c24xx_clk_enable(S3C2410_CLKCON_IIC, 0);
 594         s3c24xx_clk_enable(S3C2410_CLKCON_SPI, 0);
 595
 596         mutex_unlock(&clocks_mutex);
 597
 598         /* assume uart clocks are correctly setup */
 599
 600         /* register our clocks */
 601
 602         if (s3c24xx_register_clock(&clk_xtal) < 0)
 603                 printk(KERN_ERR "failed to register master xtal\n");
 604
 605         if (s3c24xx_register_clock(&clk_upll) < 0)
 606                 printk(KERN_ERR "failed to register upll clock\n");
 607
 608         if (s3c24xx_register_clock(&clk_f) < 0)
 609                 printk(KERN_ERR "failed to register cpu fclk\n");
 610
 611         if (s3c24xx_register_clock(&clk_h) < 0)
 612                 printk(KERN_ERR "failed to register cpu hclk\n");
 613
 614         if (s3c24xx_register_clock(&clk_p) < 0)
 615                 printk(KERN_ERR "failed to register cpu pclk\n");
 616
 617
 618         if (s3c24xx_register_clock(&clk_usb_bus) < 0)
 619                 printk(KERN_ERR "failed to register usb bus clock\n");
 620
 621         /* register clocks from clock array */
 622
 623         for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
 624                 ret = s3c24xx_register_clock(clkp);
 625                 if (ret < 0) {
 626                         printk(KERN_ERR "Failed to register clock %s (%d)\n",
 627                                clkp->name, ret);
 628                 }
 629         }
 630
 631         /* show the clock-slow value */
 632
 633         printk("CLOCK: Slow mode (%ld.%ld MHz), %s, MPLL %s, UPLL %s\n",
 634                print_mhz(xtal / ( 2 * S3C2410_CLKSLOW_GET_SLOWVAL(clkslow))),
 635                (clkslow & S3C2410_CLKSLOW_SLOW) ? "slow" : "fast",
 636                (clkslow & S3C2410_CLKSLOW_MPLL_OFF) ? "off" : "on",
 637                (clkslow & S3C2410_CLKSLOW_UCLK_OFF) ? "off" : "on");
 638
 639         return 0;
 640 }