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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
  42 #include <asm/hardware.h>
  43 #include <asm/irq.h>
  44 #include <asm/io.h>
  45
  46 #include <asm/arch/regs-clock.h>
  47
  48 #include "clock.h"
  49 #include "cpu.h"
  50
  51 /* clock information */
  52
  53 static LIST_HEAD(clocks);
  54 static DEFINE_MUTEX(clocks_mutex);
  55
  56 /* old functions */
  57
  58 void inline s3c24xx_clk_enable(unsigned int clocks, unsigned int enable)
  59 {
  60         unsigned long clkcon;
  61
  62         clkcon = __raw_readl(S3C2410_CLKCON);
  63
  64         if (enable)
  65                 clkcon |= clocks;
  66         else
  67                 clkcon &= ~clocks;
  68
  69         /* ensure none of the special function bits set */
  70         clkcon &= ~(S3C2410_CLKCON_IDLE|S3C2410_CLKCON_POWER);
  71
  72         __raw_writel(clkcon, S3C2410_CLKCON);
  73 }
  74
  75 /* enable and disable calls for use with the clk struct */
  76
  77 static int clk_null_enable(struct clk *clk, int enable)
  78 {
  79         return 0;
  80 }
  81
  82 int s3c24xx_clkcon_enable(struct clk *clk, int enable)
  83 {
  84         s3c24xx_clk_enable(clk->ctrlbit, enable);
  85         return 0;
  86 }
  87
  88 /* Clock API calls */
  89
  90 struct clk *clk_get(struct device *dev, const char *id)
  91 {
  92         struct clk *p;
  93         struct clk *clk = ERR_PTR(-ENOENT);
  94         int idno;
  95
  96         if (dev == NULL || dev->bus != &platform_bus_type)
  97                 idno = -1;
  98         else
  99                 idno = to_platform_device(dev)->id;
 100
 101         mutex_lock(&clocks_mutex);
 102
 103         list_for_each_entry(p, &clocks, list) {
 104                 if (p->id == idno &&
 105                     strcmp(id, p->name) == 0 &&
 106                     try_module_get(p->owner)) {
 107                         clk = p;
 108                         break;
 109                 }
 110         }
 111
 112         /* check for the case where a device was supplied, but the
 113          * clock that was being searched for is not device specific */
 114
 115         if (IS_ERR(clk)) {
 116                 list_for_each_entry(p, &clocks, list) {
 117                         if (p->id == -1 && strcmp(id, p->name) == 0 &&
 118                             try_module_get(p->owner)) {
 119                                 clk = p;
 120                                 break;
 121                         }
 122                 }
 123         }
 124
 125         mutex_unlock(&clocks_mutex);
 126         return clk;
 127 }
 128
 129 void clk_put(struct clk *clk)
 130 {
 131         module_put(clk->owner);
 132 }
 133
 134 int clk_enable(struct clk *clk)
 135 {
 136         if (IS_ERR(clk) || clk == NULL)
 137                 return -EINVAL;
 138
 139         clk_enable(clk->parent);
 140
 141         mutex_lock(&clocks_mutex);
 142
 143         if ((clk->usage++) == 0)
 144                 (clk->enable)(clk, 1);
 145
 146         mutex_unlock(&clocks_mutex);
 147         return 0;
 148 }
 149
 150 void clk_disable(struct clk *clk)
 151 {
 152         if (IS_ERR(clk) || clk == NULL)
 153                 return;
 154
 155         mutex_lock(&clocks_mutex);
 156
 157         if ((--clk->usage) == 0)
 158                 (clk->enable)(clk, 0);
 159
 160         mutex_unlock(&clocks_mutex);
 161         clk_disable(clk->parent);
 162 }
 163
 164
 165 unsigned long clk_get_rate(struct clk *clk)
 166 {
 167         if (IS_ERR(clk))
 168                 return 0;
 169
 170         if (clk->rate != 0)
 171                 return clk->rate;
 172
 173         while (clk->parent != NULL && clk->rate == 0)
 174                 clk = clk->parent;
 175
 176         return clk->rate;
 177 }
 178
 179 long clk_round_rate(struct clk *clk, unsigned long rate)
 180 {
 181         return rate;
 182 }
 183
 184 int clk_set_rate(struct clk *clk, unsigned long rate)
 185 {
 186         return -EINVAL;
 187 }
 188
 189 struct clk *clk_get_parent(struct clk *clk)
 190 {
 191         return clk->parent;
 192 }
 193
 194 EXPORT_SYMBOL(clk_get);
 195 EXPORT_SYMBOL(clk_put);
 196 EXPORT_SYMBOL(clk_enable);
 197 EXPORT_SYMBOL(clk_disable);
 198 EXPORT_SYMBOL(clk_get_rate);
 199 EXPORT_SYMBOL(clk_round_rate);
 200 EXPORT_SYMBOL(clk_set_rate);
 201 EXPORT_SYMBOL(clk_get_parent);
 202
 203 /* base clocks */
 204
 205 static struct clk clk_xtal = {
 206         .name           = "xtal",
 207         .id             = -1,
 208         .rate           = 0,
 209         .parent         = NULL,
 210         .ctrlbit        = 0,
 211 };
 212
 213 static struct clk clk_f = {
 214         .name           = "fclk",
 215         .id             = -1,
 216         .rate           = 0,
 217         .parent         = NULL,
 218         .ctrlbit        = 0,
 219 };
 220
 221 static struct clk clk_h = {
 222         .name           = "hclk",
 223         .id             = -1,
 224         .rate           = 0,
 225         .parent         = NULL,
 226         .ctrlbit        = 0,
 227 };
 228
 229 static struct clk clk_p = {
 230         .name           = "pclk",
 231         .id             = -1,
 232         .rate           = 0,
 233         .parent         = NULL,
 234         .ctrlbit        = 0,
 235 };
 236
 237 /* clocks that could be registered by external code */
 238
 239 struct clk s3c24xx_dclk0 = {
 240         .name           = "dclk0",
 241         .id             = -1,
 242 };
 243
 244 struct clk s3c24xx_dclk1 = {
 245         .name           = "dclk1",
 246         .id             = -1,
 247 };
 248
 249 struct clk s3c24xx_clkout0 = {
 250         .name           = "clkout0",
 251         .id             = -1,
 252 };
 253
 254 struct clk s3c24xx_clkout1 = {
 255         .name           = "clkout1",
 256         .id             = -1,
 257 };
 258
 259 struct clk s3c24xx_uclk = {
 260         .name           = "uclk",
 261         .id             = -1,
 262 };
 263
 264
 265 /* clock definitions */
 266
 267 static struct clk init_clocks[] = {
 268         {
 269                 .name           = "nand",
 270                 .id             = -1,
 271                 .parent         = &clk_h,
 272                 .enable         = s3c24xx_clkcon_enable,
 273                 .ctrlbit        = S3C2410_CLKCON_NAND,
 274         }, {
 275                 .name           = "lcd",
 276                 .id             = -1,
 277                 .parent         = &clk_h,
 278                 .enable         = s3c24xx_clkcon_enable,
 279                 .ctrlbit        = S3C2410_CLKCON_LCDC,
 280         }, {
 281                 .name           = "usb-host",
 282                 .id             = -1,
 283                 .parent         = &clk_h,
 284                 .enable         = s3c24xx_clkcon_enable,
 285                 .ctrlbit        = S3C2410_CLKCON_USBH,
 286         }, {
 287                 .name           = "usb-device",
 288                 .id             = -1,
 289                 .parent         = &clk_h,
 290                 .enable         = s3c24xx_clkcon_enable,
 291                 .ctrlbit        = S3C2410_CLKCON_USBD,
 292         }, {
 293                 .name           = "timers",
 294                 .id             = -1,
 295                 .parent         = &clk_p,
 296                 .enable         = s3c24xx_clkcon_enable,
 297                 .ctrlbit        = S3C2410_CLKCON_PWMT,
 298         }, {
 299                 .name           = "sdi",
 300                 .id             = -1,
 301                 .parent         = &clk_p,
 302                 .enable         = s3c24xx_clkcon_enable,
 303                 .ctrlbit        = S3C2410_CLKCON_SDI,
 304         }, {
 305                 .name           = "uart",
 306                 .id             = 0,
 307                 .parent         = &clk_p,
 308                 .enable         = s3c24xx_clkcon_enable,
 309                 .ctrlbit        = S3C2410_CLKCON_UART0,
 310         }, {
 311                 .name           = "uart",
 312                 .id             = 1,
 313                 .parent         = &clk_p,
 314                 .enable         = s3c24xx_clkcon_enable,
 315                 .ctrlbit        = S3C2410_CLKCON_UART1,
 316         }, {
 317                 .name           = "uart",
 318                 .id             = 2,
 319                 .parent         = &clk_p,
 320                 .enable         = s3c24xx_clkcon_enable,
 321                 .ctrlbit        = S3C2410_CLKCON_UART2,
 322         }, {
 323                 .name           = "gpio",
 324                 .id             = -1,
 325                 .parent         = &clk_p,
 326                 .enable         = s3c24xx_clkcon_enable,
 327                 .ctrlbit        = S3C2410_CLKCON_GPIO,
 328         }, {
 329                 .name           = "rtc",
 330                 .id             = -1,
 331                 .parent         = &clk_p,
 332                 .enable         = s3c24xx_clkcon_enable,
 333                 .ctrlbit        = S3C2410_CLKCON_RTC,
 334         }, {
 335                 .name           = "adc",
 336                 .id             = -1,
 337                 .parent         = &clk_p,
 338                 .enable         = s3c24xx_clkcon_enable,
 339                 .ctrlbit        = S3C2410_CLKCON_ADC,
 340         }, {
 341                 .name           = "i2c",
 342                 .id             = -1,
 343                 .parent         = &clk_p,
 344                 .enable         = s3c24xx_clkcon_enable,
 345                 .ctrlbit        = S3C2410_CLKCON_IIC,
 346         }, {
 347                 .name           = "iis",
 348                 .id             = -1,
 349                 .parent         = &clk_p,
 350                 .enable         = s3c24xx_clkcon_enable,
 351                 .ctrlbit        = S3C2410_CLKCON_IIS,
 352         }, {
 353                 .name           = "spi",
 354                 .id             = -1,
 355                 .parent         = &clk_p,
 356                 .enable         = s3c24xx_clkcon_enable,
 357                 .ctrlbit        = S3C2410_CLKCON_SPI,
 358         }, {
 359                 .name           = "watchdog",
 360                 .id             = -1,
 361                 .parent         = &clk_p,
 362                 .ctrlbit        = 0,
 363         }
 364 };
 365
 366 /* initialise the clock system */
 367
 368 int s3c24xx_register_clock(struct clk *clk)
 369 {
 370         clk->owner = THIS_MODULE;
 371
 372         if (clk->enable == NULL)
 373                 clk->enable = clk_null_enable;
 374
 375         /* if this is a standard clock, set the usage state */
 376
 377         if (clk->ctrlbit) {
 378                 unsigned long clkcon = __raw_readl(S3C2410_CLKCON);
 379
 380                 clk->usage = (clkcon & clk->ctrlbit) ? 1 : 0;
 381         }
 382
 383         /* add to the list of available clocks */
 384
 385         mutex_lock(&clocks_mutex);
 386         list_add(&clk->list, &clocks);
 387         mutex_unlock(&clocks_mutex);
 388
 389         return 0;
 390 }
 391
 392 /* initalise all the clocks */
 393
 394 int __init s3c24xx_setup_clocks(unsigned long xtal,
 395                                 unsigned long fclk,
 396                                 unsigned long hclk,
 397                                 unsigned long pclk)
 398 {
 399         unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
 400         struct clk *clkp = init_clocks;
 401         int ptr;
 402         int ret;
 403
 404         printk(KERN_INFO "S3C2410 Clocks, (c) 2004 Simtec Electronics\n");
 405
 406         /* initialise the main system clocks */
 407
 408         clk_xtal.rate = xtal;
 409
 410         clk_h.rate = hclk;
 411         clk_p.rate = pclk;
 412         clk_f.rate = fclk;
 413
 414         /* We must be careful disabling the clocks we are not intending to
 415          * be using at boot time, as subsytems such as the LCD which do
 416          * their own DMA requests to the bus can cause the system to lockup
 417          * if they where in the middle of requesting bus access.
 418          *
 419          * Disabling the LCD clock if the LCD is active is very dangerous,
 420          * and therefore the bootloader should be  careful to not enable
 421          * the LCD clock if it is not needed.
 422         */
 423
 424         mutex_lock(&clocks_mutex);
 425
 426         s3c24xx_clk_enable(S3C2410_CLKCON_NAND, 0);
 427         s3c24xx_clk_enable(S3C2410_CLKCON_USBH, 0);
 428         s3c24xx_clk_enable(S3C2410_CLKCON_USBD, 0);
 429         s3c24xx_clk_enable(S3C2410_CLKCON_ADC, 0);
 430         s3c24xx_clk_enable(S3C2410_CLKCON_IIC, 0);
 431         s3c24xx_clk_enable(S3C2410_CLKCON_SPI, 0);
 432
 433         mutex_unlock(&clocks_mutex);
 434
 435         /* assume uart clocks are correctly setup */
 436
 437         /* register our clocks */
 438
 439         if (s3c24xx_register_clock(&clk_xtal) < 0)
 440                 printk(KERN_ERR "failed to register master xtal\n");
 441
 442         if (s3c24xx_register_clock(&clk_f) < 0)
 443                 printk(KERN_ERR "failed to register cpu fclk\n");
 444
 445         if (s3c24xx_register_clock(&clk_h) < 0)
 446                 printk(KERN_ERR "failed to register cpu hclk\n");
 447
 448         if (s3c24xx_register_clock(&clk_p) < 0)
 449                 printk(KERN_ERR "failed to register cpu pclk\n");
 450
 451         /* register clocks from clock array */
 452
 453         for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
 454                 ret = s3c24xx_register_clock(clkp);
 455                 if (ret < 0) {
 456                         printk(KERN_ERR "Failed to register clock %s (%d)\n",
 457                                clkp->name, ret);
 458                 }
 459         }
 460
 461         /* show the clock-slow value */
 462
 463         printk("CLOCK: Slow mode (%ld.%ld MHz), %s, MPLL %s, UPLL %s\n",
 464                print_mhz(xtal / ( 2 * S3C2410_CLKSLOW_GET_SLOWVAL(clkslow))),
 465                (clkslow & S3C2410_CLKSLOW_SLOW) ? "slow" : "fast",
 466                (clkslow & S3C2410_CLKSLOW_MPLL_OFF) ? "off" : "on",
 467                (clkslow & S3C2410_CLKSLOW_UCLK_OFF) ? "off" : "on");
 468
 469         return 0;
 470 }