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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/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         idno = (dev == NULL) ? -1 : to_platform_device(dev)->id;
 102
 103         down(&clocks_sem);
 104
 105         list_for_each_entry(p, &clocks, list) {
 106                 if (p->id == idno &&
 107                     strcmp(id, p->name) == 0 &&
 108                     try_module_get(p->owner)) {
 109                         clk = p;
 110                         break;
 111                 }
 112         }
 113
 114         /* check for the case where a device was supplied, but the
 115          * clock that was being searched for is not device specific */
 116
 117         if (IS_ERR(clk)) {
 118                 list_for_each_entry(p, &clocks, list) {
 119                         if (p->id == -1 && strcmp(id, p->name) == 0 &&
 120                             try_module_get(p->owner)) {
 121                                 clk = p;
 122                                 break;
 123                         }
 124                 }
 125         }
 126
 127         up(&clocks_sem);
 128         return clk;
 129 }
 130
 131 void clk_put(struct clk *clk)
 132 {
 133         module_put(clk->owner);
 134 }
 135
 136 int clk_enable(struct clk *clk)
 137 {
 138         if (IS_ERR(clk))
 139                 return -EINVAL;
 140
 141         return (clk->enable)(clk, 1);
 142 }
 143
 144 void clk_disable(struct clk *clk)
 145 {
 146         if (!IS_ERR(clk))
 147                 (clk->enable)(clk, 0);
 148 }
 149
 150
 151 int clk_use(struct clk *clk)
 152 {
 153         atomic_inc(&clk->used);
 154         return 0;
 155 }
 156
 157
 158 void clk_unuse(struct clk *clk)
 159 {
 160         atomic_dec(&clk->used);
 161 }
 162
 163 unsigned long clk_get_rate(struct clk *clk)
 164 {
 165         if (IS_ERR(clk))
 166                 return 0;
 167
 168         if (clk->rate != 0)
 169                 return clk->rate;
 170
 171         while (clk->parent != NULL && clk->rate == 0)
 172                 clk = clk->parent;
 173
 174         return clk->rate;
 175 }
 176
 177 long clk_round_rate(struct clk *clk, unsigned long rate)
 178 {
 179         return rate;
 180 }
 181
 182 int clk_set_rate(struct clk *clk, unsigned long rate)
 183 {
 184         return -EINVAL;
 185 }
 186
 187 struct clk *clk_get_parent(struct clk *clk)
 188 {
 189         return clk->parent;
 190 }
 191
 192 EXPORT_SYMBOL(clk_get);
 193 EXPORT_SYMBOL(clk_put);
 194 EXPORT_SYMBOL(clk_enable);
 195 EXPORT_SYMBOL(clk_disable);
 196 EXPORT_SYMBOL(clk_use);
 197 EXPORT_SYMBOL(clk_unuse);
 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         { .name    = "nand",
 269           .id      = -1,
 270           .parent  = &clk_h,
 271           .enable  = s3c24xx_clkcon_enable,
 272           .ctrlbit = S3C2410_CLKCON_NAND
 273         },
 274         { .name    = "lcd",
 275           .id      = -1,
 276           .parent  = &clk_h,
 277           .enable  = s3c24xx_clkcon_enable,
 278           .ctrlbit = S3C2410_CLKCON_LCDC
 279         },
 280         { .name    = "usb-host",
 281           .id      = -1,
 282           .parent  = &clk_h,
 283           .enable  = s3c24xx_clkcon_enable,
 284           .ctrlbit = S3C2410_CLKCON_USBH
 285         },
 286         { .name    = "usb-device",
 287           .id      = -1,
 288           .parent  = &clk_h,
 289           .enable  = s3c24xx_clkcon_enable,
 290           .ctrlbit = S3C2410_CLKCON_USBD
 291         },
 292         { .name    = "timers",
 293           .id      = -1,
 294           .parent  = &clk_p,
 295           .enable  = s3c24xx_clkcon_enable,
 296           .ctrlbit = S3C2410_CLKCON_PWMT
 297         },
 298         { .name    = "sdi",
 299           .id      = -1,
 300           .parent  = &clk_p,
 301           .enable  = s3c24xx_clkcon_enable,
 302           .ctrlbit = S3C2410_CLKCON_SDI
 303         },
 304         { .name    = "uart",
 305           .id      = 0,
 306           .parent  = &clk_p,
 307           .enable  = s3c24xx_clkcon_enable,
 308           .ctrlbit = S3C2410_CLKCON_UART0
 309         },
 310         { .name    = "uart",
 311           .id      = 1,
 312           .parent  = &clk_p,
 313           .enable  = s3c24xx_clkcon_enable,
 314           .ctrlbit = S3C2410_CLKCON_UART1
 315         },
 316         { .name    = "uart",
 317           .id      = 2,
 318           .parent  = &clk_p,
 319           .enable  = s3c24xx_clkcon_enable,
 320           .ctrlbit = S3C2410_CLKCON_UART2
 321         },
 322         { .name    = "gpio",
 323           .id      = -1,
 324           .parent  = &clk_p,
 325           .enable  = s3c24xx_clkcon_enable,
 326           .ctrlbit = S3C2410_CLKCON_GPIO
 327         },
 328         { .name    = "rtc",
 329           .id      = -1,
 330           .parent  = &clk_p,
 331           .enable  = s3c24xx_clkcon_enable,
 332           .ctrlbit = S3C2410_CLKCON_RTC
 333         },
 334         { .name    = "adc",
 335           .id      = -1,
 336           .parent  = &clk_p,
 337           .enable  = s3c24xx_clkcon_enable,
 338           .ctrlbit = S3C2410_CLKCON_ADC
 339         },
 340         { .name    = "i2c",
 341           .id      = -1,
 342           .parent  = &clk_p,
 343           .enable  = s3c24xx_clkcon_enable,
 344           .ctrlbit = S3C2410_CLKCON_IIC
 345         },
 346         { .name    = "iis",
 347           .id      = -1,
 348           .parent  = &clk_p,
 349           .enable  = s3c24xx_clkcon_enable,
 350           .ctrlbit = S3C2410_CLKCON_IIS
 351         },
 352         { .name    = "spi",
 353           .id      = -1,
 354           .parent  = &clk_p,
 355           .enable  = s3c24xx_clkcon_enable,
 356           .ctrlbit = S3C2410_CLKCON_SPI
 357         },
 358         { .name    = "watchdog",
 359           .id      = -1,
 360           .parent  = &clk_p,
 361           .ctrlbit = 0
 362         }
 363 };
 364
 365 /* initialise the clock system */
 366
 367 int s3c24xx_register_clock(struct clk *clk)
 368 {
 369         clk->owner = THIS_MODULE;
 370         atomic_set(&clk->used, 0);
 371
 372         if (clk->enable == NULL)
 373                 clk->enable = clk_null_enable;
 374
 375         /* add to the list of available clocks */
 376
 377         down(&clocks_sem);
 378         list_add(&clk->list, &clocks);
 379         up(&clocks_sem);
 380
 381         return 0;
 382 }
 383
 384 /* initalise all the clocks */
 385
 386 int __init s3c24xx_setup_clocks(unsigned long xtal,
 387                                 unsigned long fclk,
 388                                 unsigned long hclk,
 389                                 unsigned long pclk)
 390 {
 391         struct clk *clkp = init_clocks;
 392         int ptr;
 393         int ret;
 394
 395         printk(KERN_INFO "S3C2410 Clocks, (c) 2004 Simtec Electronics\n");
 396
 397         /* initialise the main system clocks */
 398
 399         clk_xtal.rate = xtal;
 400
 401         clk_h.rate = hclk;
 402         clk_p.rate = pclk;
 403         clk_f.rate = fclk;
 404
 405         /* it looks like just setting the register here is not good
 406          * enough, and causes the odd hang at initial boot time, so
 407          * do all of them indivdually.
 408          *
 409          * I think disabling the LCD clock if the LCD is active is
 410          * very dangerous, and therefore the bootloader should be
 411          * careful to not enable the LCD clock if it is not needed.
 412          *
 413          * and of course, this looks neater
 414          */
 415
 416         s3c24xx_clk_enable(S3C2410_CLKCON_NAND, 0);
 417         s3c24xx_clk_enable(S3C2410_CLKCON_USBH, 0);
 418         s3c24xx_clk_enable(S3C2410_CLKCON_USBD, 0);
 419         s3c24xx_clk_enable(S3C2410_CLKCON_ADC, 0);
 420         s3c24xx_clk_enable(S3C2410_CLKCON_IIC, 0);
 421         s3c24xx_clk_enable(S3C2410_CLKCON_SPI, 0);
 422
 423         /* assume uart clocks are correctly setup */
 424
 425         /* register our clocks */
 426
 427         if (s3c24xx_register_clock(&clk_xtal) < 0)
 428                 printk(KERN_ERR "failed to register master xtal\n");
 429
 430         if (s3c24xx_register_clock(&clk_f) < 0)
 431                 printk(KERN_ERR "failed to register cpu fclk\n");
 432
 433         if (s3c24xx_register_clock(&clk_h) < 0)
 434                 printk(KERN_ERR "failed to register cpu hclk\n");
 435
 436         if (s3c24xx_register_clock(&clk_p) < 0)
 437                 printk(KERN_ERR "failed to register cpu pclk\n");
 438
 439         /* register clocks from clock array */
 440
 441         for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
 442                 ret = s3c24xx_register_clock(clkp);
 443                 if (ret < 0) {
 444                         printk(KERN_ERR "Failed to register clock %s (%d)\n",
 445                                clkp->name, ret);
 446                 }
 447         }
 448
 449         return 0;
 450 }