arch/arm/mach-s3c24xx/clock-s3c2410.c

   1 /*
   2  * Copyright (c) 2006 Simtec Electronics
   3  *      Ben Dooks <ben@simtec.co.uk>
   4  *
   5  * S3C2410,S3C2440,S3C2442 Clock control support
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20 */
  21
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/kernel.h>
  25 #include <linux/list.h>
  26 #include <linux/errno.h>
  27 #include <linux/err.h>
  28 #include <linux/device.h>
  29 #include <linux/clk.h>
  30 #include <linux/mutex.h>
  31 #include <linux/delay.h>
  32 #include <linux/serial_core.h>
  33 #include <linux/io.h>
  34
  35 #include <asm/mach/map.h>
  36
  37 #include <mach/hardware.h>
  38
  39 #include <plat/regs-serial.h>
  40 #include <mach/regs-clock.h>
  41 #include <mach/regs-gpio.h>
  42
  43 #include <plat/clock.h>
  44 #include <plat/cpu.h>
  45
  46 int s3c2410_clkcon_enable(struct clk *clk, int enable)
  47 {
  48         unsigned int clocks = clk->ctrlbit;
  49         unsigned long clkcon;
  50
  51         clkcon = __raw_readl(S3C2410_CLKCON);
  52
  53         if (enable)
  54                 clkcon |= clocks;
  55         else
  56                 clkcon &= ~clocks;
  57
  58         /* ensure none of the special function bits set */
  59         clkcon &= ~(S3C2410_CLKCON_IDLE|S3C2410_CLKCON_POWER);
  60
  61         __raw_writel(clkcon, S3C2410_CLKCON);
  62
  63         return 0;
  64 }
  65
  66 static int s3c2410_upll_enable(struct clk *clk, int enable)
  67 {
  68         unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
  69         unsigned long orig = clkslow;
  70
  71         if (enable)
  72                 clkslow &= ~S3C2410_CLKSLOW_UCLK_OFF;
  73         else
  74                 clkslow |= S3C2410_CLKSLOW_UCLK_OFF;
  75
  76         __raw_writel(clkslow, S3C2410_CLKSLOW);
  77
  78         /* if we started the UPLL, then allow to settle */
  79
  80         if (enable && (orig & S3C2410_CLKSLOW_UCLK_OFF))
  81                 udelay(200);
  82
  83         return 0;
  84 }
  85
  86 /* standard clock definitions */
  87
  88 static struct clk init_clocks_off[] = {
  89         {
  90                 .name           = "nand",
  91                 .parent         = &clk_h,
  92                 .enable         = s3c2410_clkcon_enable,
  93                 .ctrlbit        = S3C2410_CLKCON_NAND,
  94         }, {
  95                 .name           = "sdi",
  96                 .parent         = &clk_p,
  97                 .enable         = s3c2410_clkcon_enable,
  98                 .ctrlbit        = S3C2410_CLKCON_SDI,
  99         }, {
 100                 .name           = "adc",
 101                 .parent         = &clk_p,
 102                 .enable         = s3c2410_clkcon_enable,
 103                 .ctrlbit        = S3C2410_CLKCON_ADC,
 104         }, {
 105                 .name           = "i2c",
 106                 .parent         = &clk_p,
 107                 .enable         = s3c2410_clkcon_enable,
 108                 .ctrlbit        = S3C2410_CLKCON_IIC,
 109         }, {
 110                 .name           = "iis",
 111                 .parent         = &clk_p,
 112                 .enable         = s3c2410_clkcon_enable,
 113                 .ctrlbit        = S3C2410_CLKCON_IIS,
 114         }, {
 115                 .name           = "spi",
 116                 .parent         = &clk_p,
 117                 .enable         = s3c2410_clkcon_enable,
 118                 .ctrlbit        = S3C2410_CLKCON_SPI,
 119         }
 120 };
 121
 122 static struct clk clk_lcd = {
 123         .name           = "lcd",
 124         .parent         = &clk_h,
 125         .enable         = s3c2410_clkcon_enable,
 126         .ctrlbit        = S3C2410_CLKCON_LCDC,
 127 };
 128
 129 static struct clk clk_gpio = {
 130         .name           = "gpio",
 131         .parent         = &clk_p,
 132         .enable         = s3c2410_clkcon_enable,
 133         .ctrlbit        = S3C2410_CLKCON_GPIO,
 134 };
 135
 136 static struct clk clk_usb_host = {
 137         .name           = "usb-host",
 138         .parent         = &clk_h,
 139         .enable         = s3c2410_clkcon_enable,
 140         .ctrlbit        = S3C2410_CLKCON_USBH,
 141 };
 142
 143 static struct clk clk_usb_device = {
 144         .name           = "usb-device",
 145         .parent         = &clk_h,
 146         .enable         = s3c2410_clkcon_enable,
 147         .ctrlbit        = S3C2410_CLKCON_USBD,
 148 };
 149
 150 static struct clk clk_timers = {
 151         .name           = "timers",
 152         .parent         = &clk_p,
 153         .enable         = s3c2410_clkcon_enable,
 154         .ctrlbit        = S3C2410_CLKCON_PWMT,
 155 };
 156
 157 struct clk s3c24xx_clk_uart0 = {
 158         .name           = "uart",
 159         .devname        = "s3c2410-uart.0",
 160         .parent         = &clk_p,
 161         .enable         = s3c2410_clkcon_enable,
 162         .ctrlbit        = S3C2410_CLKCON_UART0,
 163 };
 164
 165 struct clk s3c24xx_clk_uart1 = {
 166         .name           = "uart",
 167         .devname        = "s3c2410-uart.1",
 168         .parent         = &clk_p,
 169         .enable         = s3c2410_clkcon_enable,
 170         .ctrlbit        = S3C2410_CLKCON_UART1,
 171 };
 172
 173 struct clk s3c24xx_clk_uart2 = {
 174         .name           = "uart",
 175         .devname        = "s3c2410-uart.2",
 176         .parent         = &clk_p,
 177         .enable         = s3c2410_clkcon_enable,
 178         .ctrlbit        = S3C2410_CLKCON_UART2,
 179 };
 180
 181 static struct clk clk_rtc = {
 182         .name           = "rtc",
 183         .parent         = &clk_p,
 184         .enable         = s3c2410_clkcon_enable,
 185         .ctrlbit        = S3C2410_CLKCON_RTC,
 186 };
 187
 188 static struct clk clk_watchdog = {
 189         .name           = "watchdog",
 190         .parent         = &clk_p,
 191         .ctrlbit        = 0,
 192 };
 193
 194 static struct clk clk_usb_bus_host = {
 195         .name           = "usb-bus-host",
 196         .parent         = &clk_usb_bus,
 197 };
 198
 199 static struct clk clk_usb_bus_gadget = {
 200         .name           = "usb-bus-gadget",
 201         .parent         = &clk_usb_bus,
 202 };
 203
 204 static struct clk *init_clocks[] = {
 205         &clk_lcd,
 206         &clk_gpio,
 207         &clk_usb_host,
 208         &clk_usb_device,
 209         &clk_timers,
 210         &s3c24xx_clk_uart0,
 211         &s3c24xx_clk_uart1,
 212         &s3c24xx_clk_uart2,
 213         &clk_rtc,
 214         &clk_watchdog,
 215         &clk_usb_bus_host,
 216         &clk_usb_bus_gadget,
 217 };
 218
 219 /* s3c2410_baseclk_add()
 220  *
 221  * Add all the clocks used by the s3c2410 or compatible CPUs
 222  * such as the S3C2440 and S3C2442.
 223  *
 224  * We cannot use a system device as we are needed before any
 225  * of the init-calls that initialise the devices are actually
 226  * done.
 227 */
 228
 229 int __init s3c2410_baseclk_add(void)
 230 {
 231         unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
 232         unsigned long clkcon  = __raw_readl(S3C2410_CLKCON);
 233         struct clk *xtal;
 234         int ret;
 235         int ptr;
 236
 237         clk_upll.enable = s3c2410_upll_enable;
 238
 239         if (s3c24xx_register_clock(&clk_usb_bus) < 0)
 240                 printk(KERN_ERR "failed to register usb bus clock\n");
 241
 242         /* register clocks from clock array */
 243
 244         for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++) {
 245                 struct clk *clkp = init_clocks[ptr];
 246
 247                 /* ensure that we note the clock state */
 248
 249                 clkp->usage = clkcon & clkp->ctrlbit ? 1 : 0;
 250
 251                 ret = s3c24xx_register_clock(clkp);
 252                 if (ret < 0) {
 253                         printk(KERN_ERR "Failed to register clock %s (%d)\n",
 254                                clkp->name, ret);
 255                 }
 256         }
 257
 258         /* We must be careful disabling the clocks we are not intending to
 259          * be using at boot time, as subsystems such as the LCD which do
 260          * their own DMA requests to the bus can cause the system to lockup
 261          * if they where in the middle of requesting bus access.
 262          *
 263          * Disabling the LCD clock if the LCD is active is very dangerous,
 264          * and therefore the bootloader should be careful to not enable
 265          * the LCD clock if it is not needed.
 266         */
 267
 268         /* install (and disable) the clocks we do not need immediately */
 269
 270         s3c_register_clocks(init_clocks_off, ARRAY_SIZE(init_clocks_off));
 271         s3c_disable_clocks(init_clocks_off, ARRAY_SIZE(init_clocks_off));
 272
 273         /* show the clock-slow value */
 274
 275         xtal = clk_get(NULL, "xtal");
 276
 277         printk("CLOCK: Slow mode (%ld.%ld MHz), %s, MPLL %s, UPLL %s\n",
 278                print_mhz(clk_get_rate(xtal) /
 279                          ( 2 * S3C2410_CLKSLOW_GET_SLOWVAL(clkslow))),
 280                (clkslow & S3C2410_CLKSLOW_SLOW) ? "slow" : "fast",
 281                (clkslow & S3C2410_CLKSLOW_MPLL_OFF) ? "off" : "on",
 282                (clkslow & S3C2410_CLKSLOW_UCLK_OFF) ? "off" : "on");
 283
 284         return 0;
 285 }