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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
  38 #include <linux/interrupt.h>
  39 #include <linux/ioport.h>
  40
  41 #include <asm/hardware.h>
  42 #include <asm/atomic.h>
  43 #include <asm/irq.h>
  44 #include <asm/io.h>
  45
  46 #include <asm/hardware/clock.h>
  47 #include <asm/arch/regs-clock.h>
  48
  49 #include "clock.h"
  50 #include "cpu.h"
  51
  52 /* clock information */
  53
  54 static LIST_HEAD(clocks);
  55 static DECLARE_MUTEX(clocks_sem);
  56
  57 /* old functions */
  58
  59 void inline s3c24xx_clk_enable(unsigned int clocks, unsigned int enable)
  60 {
  61         unsigned long clkcon;
  62         unsigned long flags;
  63
  64         local_irq_save(flags);
  65
  66         clkcon = __raw_readl(S3C2410_CLKCON);
  67         clkcon &= ~clocks;
  68
  69         if (enable)
  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         local_irq_restore(flags);
  78 }
  79
  80 /* enable and disable calls for use with the clk struct */
  81
  82 static int clk_null_enable(struct clk *clk, int enable)
  83 {
  84         return 0;
  85 }
  86
  87 int s3c24xx_clkcon_enable(struct clk *clk, int enable)
  88 {
  89         s3c24xx_clk_enable(clk->ctrlbit, enable);
  90         return 0;
  91 }
  92
  93 /* Clock API calls */
  94
  95 struct clk *clk_get(struct device *dev, const char *id)
  96 {
  97         struct clk *p;
  98         struct clk *clk = ERR_PTR(-ENOENT);
  99         int idno;
 100
 101         if (dev == NULL || dev->bus != &platform_bus_type)
 102                 idno = -1;
 103         else
 104                 idno = to_platform_device(dev)->id;
 105
 106         down(&clocks_sem);
 107
 108         list_for_each_entry(p, &clocks, list) {
 109                 if (p->id == idno &&
 110                     strcmp(id, p->name) == 0 &&
 111                     try_module_get(p->owner)) {
 112                         clk = p;
 113                         break;
 114                 }
 115         }
 116
 117         /* check for the case where a device was supplied, but the
 118          * clock that was being searched for is not device specific */
 119
 120         if (IS_ERR(clk)) {
 121                 list_for_each_entry(p, &clocks, list) {
 122                         if (p->id == -1 && strcmp(id, p->name) == 0 &&
 123                             try_module_get(p->owner)) {
 124                                 clk = p;
 125                                 break;
 126                         }
 127                 }
 128         }
 129
 130         up(&clocks_sem);
 131         return clk;
 132 }
 133
 134 void clk_put(struct clk *clk)
 135 {
 136         module_put(clk->owner);
 137 }
 138
 139 int clk_enable(struct clk *clk)
 140 {
 141         if (IS_ERR(clk))
 142                 return -EINVAL;
 143
 144         return (clk->enable)(clk, 1);
 145 }
 146
 147 void clk_disable(struct clk *clk)
 148 {
 149         if (!IS_ERR(clk))
 150                 (clk->enable)(clk, 0);
 151 }
 152
 153
 154 int clk_use(struct clk *clk)
 155 {
 156         atomic_inc(&clk->used);
 157         return 0;
 158 }
 159
 160
 161 void clk_unuse(struct clk *clk)
 162 {
 163         atomic_dec(&clk->used);
 164 }
 165
 166 unsigned long clk_get_rate(struct clk *clk)
 167 {
 168         if (IS_ERR(clk))
 169                 return 0;
 170
 171         if (clk->rate != 0)
 172                 return clk->rate;
 173
 174         while (clk->parent != NULL && clk->rate == 0)
 175                 clk = clk->parent;
 176
 177         return clk->rate;
 178 }
 179
 180 long clk_round_rate(struct clk *clk, unsigned long rate)
 181 {
 182         return rate;
 183 }
 184
 185 int clk_set_rate(struct clk *clk, unsigned long rate)
 186 {
 187         return -EINVAL;
 188 }
 189
 190 struct clk *clk_get_parent(struct clk *clk)
 191 {
 192         return clk->parent;
 193 }
 194
 195 EXPORT_SYMBOL(clk_get);
 196 EXPORT_SYMBOL(clk_put);
 197 EXPORT_SYMBOL(clk_enable);
 198 EXPORT_SYMBOL(clk_disable);
 199 EXPORT_SYMBOL(clk_use);
 200 EXPORT_SYMBOL(clk_unuse);
 201 EXPORT_SYMBOL(clk_get_rate);
 202 EXPORT_SYMBOL(clk_round_rate);
 203 EXPORT_SYMBOL(clk_set_rate);
 204 EXPORT_SYMBOL(clk_get_parent);
 205
 206 /* base clocks */
 207
 208 static struct clk clk_xtal = {
 209         .name           = "xtal",
 210         .id             = -1,
 211         .rate           = 0,
 212         .parent         = NULL,
 213         .ctrlbit        = 0,
 214 };
 215
 216 static struct clk clk_f = {
 217         .name           = "fclk",
 218         .id             = -1,
 219         .rate           = 0,
 220         .parent         = NULL,
 221         .ctrlbit        = 0,
 222 };
 223
 224 static struct clk clk_h = {
 225         .name           = "hclk",
 226         .id             = -1,
 227         .rate           = 0,
 228         .parent         = NULL,
 229         .ctrlbit        = 0,
 230 };
 231
 232 static struct clk clk_p = {
 233         .name           = "pclk",
 234         .id             = -1,
 235         .rate           = 0,
 236         .parent         = NULL,
 237         .ctrlbit        = 0,
 238 };
 239
 240 /* clocks that could be registered by external code */
 241
 242 struct clk s3c24xx_dclk0 = {
 243         .name           = "dclk0",
 244         .id             = -1,
 245 };
 246
 247 struct clk s3c24xx_dclk1 = {
 248         .name           = "dclk1",
 249         .id             = -1,
 250 };
 251
 252 struct clk s3c24xx_clkout0 = {
 253         .name           = "clkout0",
 254         .id             = -1,
 255 };
 256
 257 struct clk s3c24xx_clkout1 = {
 258         .name           = "clkout1",
 259         .id             = -1,
 260 };
 261
 262 struct clk s3c24xx_uclk = {
 263         .name           = "uclk",
 264         .id             = -1,
 265 };
 266
 267
 268 /* clock definitions */
 269
 270 static struct clk init_clocks[] = {
 271         { .name    = "nand",
 272           .id      = -1,
 273           .parent  = &clk_h,
 274           .enable  = s3c24xx_clkcon_enable,
 275           .ctrlbit = S3C2410_CLKCON_NAND
 276         },
 277         { .name    = "lcd",
 278           .id      = -1,
 279           .parent  = &clk_h,
 280           .enable  = s3c24xx_clkcon_enable,
 281           .ctrlbit = S3C2410_CLKCON_LCDC
 282         },
 283         { .name    = "usb-host",
 284           .id      = -1,
 285           .parent  = &clk_h,
 286           .enable  = s3c24xx_clkcon_enable,
 287           .ctrlbit = S3C2410_CLKCON_USBH
 288         },
 289         { .name    = "usb-device",
 290           .id      = -1,
 291           .parent  = &clk_h,
 292           .enable  = s3c24xx_clkcon_enable,
 293           .ctrlbit = S3C2410_CLKCON_USBD
 294         },
 295         { .name    = "timers",
 296           .id      = -1,
 297           .parent  = &clk_p,
 298           .enable  = s3c24xx_clkcon_enable,
 299           .ctrlbit = S3C2410_CLKCON_PWMT
 300         },
 301         { .name    = "sdi",
 302           .id      = -1,
 303           .parent  = &clk_p,
 304           .enable  = s3c24xx_clkcon_enable,
 305           .ctrlbit = S3C2410_CLKCON_SDI
 306         },
 307         { .name    = "uart",
 308           .id      = 0,
 309           .parent  = &clk_p,
 310           .enable  = s3c24xx_clkcon_enable,
 311           .ctrlbit = S3C2410_CLKCON_UART0
 312         },
 313         { .name    = "uart",
 314           .id      = 1,
 315           .parent  = &clk_p,
 316           .enable  = s3c24xx_clkcon_enable,
 317           .ctrlbit = S3C2410_CLKCON_UART1
 318         },
 319         { .name    = "uart",
 320           .id      = 2,
 321           .parent  = &clk_p,
 322           .enable  = s3c24xx_clkcon_enable,
 323           .ctrlbit = S3C2410_CLKCON_UART2
 324         },
 325         { .name    = "gpio",
 326           .id      = -1,
 327           .parent  = &clk_p,
 328           .enable  = s3c24xx_clkcon_enable,
 329           .ctrlbit = S3C2410_CLKCON_GPIO
 330         },
 331         { .name    = "rtc",
 332           .id      = -1,
 333           .parent  = &clk_p,
 334           .enable  = s3c24xx_clkcon_enable,
 335           .ctrlbit = S3C2410_CLKCON_RTC
 336         },
 337         { .name    = "adc",
 338           .id      = -1,
 339           .parent  = &clk_p,
 340           .enable  = s3c24xx_clkcon_enable,
 341           .ctrlbit = S3C2410_CLKCON_ADC
 342         },
 343         { .name    = "i2c",
 344           .id      = -1,
 345           .parent  = &clk_p,
 346           .enable  = s3c24xx_clkcon_enable,
 347           .ctrlbit = S3C2410_CLKCON_IIC
 348         },
 349         { .name    = "iis",
 350           .id      = -1,
 351           .parent  = &clk_p,
 352           .enable  = s3c24xx_clkcon_enable,
 353           .ctrlbit = S3C2410_CLKCON_IIS
 354         },
 355         { .name    = "spi",
 356           .id      = -1,
 357           .parent  = &clk_p,
 358           .enable  = s3c24xx_clkcon_enable,
 359           .ctrlbit = S3C2410_CLKCON_SPI
 360         },
 361         { .name    = "watchdog",
 362           .id      = -1,
 363           .parent  = &clk_p,
 364           .ctrlbit = 0
 365         }
 366 };
 367
 368 /* initialise the clock system */
 369
 370 int s3c24xx_register_clock(struct clk *clk)
 371 {
 372         clk->owner = THIS_MODULE;
 373         atomic_set(&clk->used, 0);
 374
 375         if (clk->enable == NULL)
 376                 clk->enable = clk_null_enable;
 377
 378         /* add to the list of available clocks */
 379
 380         down(&clocks_sem);
 381         list_add(&clk->list, &clocks);
 382         up(&clocks_sem);
 383
 384         return 0;
 385 }
 386
 387 /* initalise all the clocks */
 388
 389 int __init s3c24xx_setup_clocks(unsigned long xtal,
 390                                 unsigned long fclk,
 391                                 unsigned long hclk,
 392                                 unsigned long pclk)
 393 {
 394         unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
 395         struct clk *clkp = init_clocks;
 396         int ptr;
 397         int ret;
 398
 399         printk(KERN_INFO "S3C2410 Clocks, (c) 2004 Simtec Electronics\n");
 400
 401         /* initialise the main system clocks */
 402
 403         clk_xtal.rate = xtal;
 404
 405         clk_h.rate = hclk;
 406         clk_p.rate = pclk;
 407         clk_f.rate = fclk;
 408
 409         /* it looks like just setting the register here is not good
 410          * enough, and causes the odd hang at initial boot time, so
 411          * do all of them indivdually.
 412          *
 413          * I think disabling the LCD clock if the LCD is active is
 414          * very dangerous, and therefore the bootloader should be
 415          * careful to not enable the LCD clock if it is not needed.
 416          *
 417          * and of course, this looks neater
 418          */
 419
 420         s3c24xx_clk_enable(S3C2410_CLKCON_NAND, 0);
 421         s3c24xx_clk_enable(S3C2410_CLKCON_USBH, 0);
 422         s3c24xx_clk_enable(S3C2410_CLKCON_USBD, 0);
 423         s3c24xx_clk_enable(S3C2410_CLKCON_ADC, 0);
 424         s3c24xx_clk_enable(S3C2410_CLKCON_IIC, 0);
 425         s3c24xx_clk_enable(S3C2410_CLKCON_SPI, 0);
 426
 427         /* assume uart clocks are correctly setup */
 428
 429         /* register our clocks */
 430
 431         if (s3c24xx_register_clock(&clk_xtal) < 0)
 432                 printk(KERN_ERR "failed to register master xtal\n");
 433
 434         if (s3c24xx_register_clock(&clk_f) < 0)
 435                 printk(KERN_ERR "failed to register cpu fclk\n");
 436
 437         if (s3c24xx_register_clock(&clk_h) < 0)
 438                 printk(KERN_ERR "failed to register cpu hclk\n");
 439
 440         if (s3c24xx_register_clock(&clk_p) < 0)
 441                 printk(KERN_ERR "failed to register cpu pclk\n");
 442
 443         /* register clocks from clock array */
 444
 445         for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
 446                 ret = s3c24xx_register_clock(clkp);
 447                 if (ret < 0) {
 448                         printk(KERN_ERR "Failed to register clock %s (%d)\n",
 449                                clkp->name, ret);
 450                 }
 451         }
 452
 453         /* show the clock-slow value */
 454
 455         printk("CLOCK: Slow mode (%ld.%ld MHz), %s, MPLL %s, UPLL %s\n",
 456                print_mhz(xtal / ( 2 * S3C2410_CLKSLOW_GET_SLOWVAL(clkslow))),
 457                (clkslow & S3C2410_CLKSLOW_SLOW) ? "slow" : "fast",
 458                (clkslow & S3C2410_CLKSLOW_MPLL_OFF) ? "off" : "on",
 459                (clkslow & S3C2410_CLKSLOW_UCLK_OFF) ? "off" : "on");
 460
 461         return 0;
 462 }