s3c2410-clock.c

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/* linux/arch/arm/mach-s3c2410/clock.c
 *
 * Copyright (c) 2006 Simtec Electronics
 *  Ben Dooks <[email protected]>
 *
 * S3C2410,S3C2440,S3C2442 Clock control support
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/clk.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/serial_core.h>
#include <linux/io.h>

#include <asm/mach/map.h>

#include <mach/hardware.h>

#include <plat/regs-serial.h>
#include <mach/regs-clock.h>
#include <mach/regs-gpio.h>

#include <plat/s3c2410.h>
#include <plat/clock.h>
#include <plat/cpu.h>

int s3c2410_clkcon_enable(struct clk *clk, int enable)
{
    unsigned int clocks = clk->ctrlbit;
    unsigned long clkcon;

    clkcon = __raw_readl(S3C2410_CLKCON);

    if (enable)
        clkcon |= clocks;
    else
        clkcon &= ~clocks;

    /* ensure none of the special function bits set */
    clkcon &= ~(S3C2410_CLKCON_IDLE|S3C2410_CLKCON_POWER);

    __raw_writel(clkcon, S3C2410_CLKCON);

    return 0;
}

static int s3c2410_upll_enable(struct clk *clk, int enable)
{
    unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
    unsigned long orig = clkslow;

    if (enable)
        clkslow &= ~S3C2410_CLKSLOW_UCLK_OFF;
    else
        clkslow |= S3C2410_CLKSLOW_UCLK_OFF;

    __raw_writel(clkslow, S3C2410_CLKSLOW);

    /* if we started the UPLL, then allow to settle */

    if (enable && (orig & S3C2410_CLKSLOW_UCLK_OFF))
        udelay(200);

    return 0;
}

/* standard clock definitions */

static struct clk init_clocks_off[] = {
    {
        .name       = "nand",
        .parent     = &clk_h,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_NAND,
    }, {
        .name       = "sdi",
        .parent     = &clk_p,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_SDI,
    }, {
        .name       = "adc",
        .parent     = &clk_p,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_ADC,
    }, {
        .name       = "i2c",
        .parent     = &clk_p,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_IIC,
    }, {
        .name       = "iis",
        .parent     = &clk_p,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_IIS,
    }, {
        .name       = "spi",
        .parent     = &clk_p,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_SPI,
    }
};

static struct clk init_clocks[] = {
    {
        .name       = "lcd",
        .parent     = &clk_h,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_LCDC,
    }, {
        .name       = "gpio",
        .parent     = &clk_p,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_GPIO,
    }, {
        .name       = "usb-host",
        .parent     = &clk_h,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_USBH,
    }, {
        .name       = "usb-device",
        .parent     = &clk_h,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_USBD,
    }, {
        .name       = "timers",
        .parent     = &clk_p,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_PWMT,
    }, {
        .name       = "uart",
        .devname    = "s3c2410-uart.0",
        .parent     = &clk_p,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_UART0,
    }, {
        .name       = "uart",
        .devname    = "s3c2410-uart.1",
        .parent     = &clk_p,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_UART1,
    }, {
        .name       = "uart",
        .devname    = "s3c2410-uart.2",
        .parent     = &clk_p,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_UART2,
    }, {
        .name       = "rtc",
        .parent     = &clk_p,
        .enable     = s3c2410_clkcon_enable,
        .ctrlbit    = S3C2410_CLKCON_RTC,
    }, {
        .name       = "watchdog",
        .parent     = &clk_p,
        .ctrlbit    = 0,
    }, {
        .name       = "usb-bus-host",
        .parent     = &clk_usb_bus,
    }, {
        .name       = "usb-bus-gadget",
        .parent     = &clk_usb_bus,
    },
};

/* s3c2410_baseclk_add()
 *
 * Add all the clocks used by the s3c2410 or compatible CPUs
 * such as the S3C2440 and S3C2442.
 *
 * We cannot use a system device as we are needed before any
 * of the init-calls that initialise the devices are actually
 * done.
*/

int __init s3c2410_baseclk_add(void)
{
    unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
    unsigned long clkcon  = __raw_readl(S3C2410_CLKCON);
    struct clk *clkp;
    struct clk *xtal;
    int ret;
    int ptr;

    clk_upll.enable = s3c2410_upll_enable;

    if (s3c24xx_register_clock(&clk_usb_bus) < 0)
        printk(KERN_ERR "failed to register usb bus clock\n");

    /* register clocks from clock array */

    clkp = init_clocks;
    for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
        /* ensure that we note the clock state */

        clkp->usage = clkcon & clkp->ctrlbit ? 1 : 0;

        ret = s3c24xx_register_clock(clkp);
        if (ret < 0) {
            printk(KERN_ERR "Failed to register clock %s (%d)\n",
                   clkp->name, ret);
        }
    }

    /* We must be careful disabling the clocks we are not intending to
     * be using at boot time, as subsystems such as the LCD which do
     * their own DMA requests to the bus can cause the system to lockup
     * if they where in the middle of requesting bus access.
     *
     * Disabling the LCD clock if the LCD is active is very dangerous,
     * and therefore the bootloader should be careful to not enable
     * the LCD clock if it is not needed.
    */

    /* install (and disable) the clocks we do not need immediately */

    s3c_register_clocks(init_clocks_off, ARRAY_SIZE(init_clocks_off));
    s3c_disable_clocks(init_clocks_off, ARRAY_SIZE(init_clocks_off));

    /* show the clock-slow value */

    xtal = clk_get(NULL, "xtal");

    printk("CLOCK: Slow mode (%ld.%ld MHz), %s, MPLL %s, UPLL %s\n",
           print_mhz(clk_get_rate(xtal) /
             ( 2 * S3C2410_CLKSLOW_GET_SLOWVAL(clkslow))),
           (clkslow & S3C2410_CLKSLOW_SLOW) ? "slow" : "fast",
           (clkslow & S3C2410_CLKSLOW_MPLL_OFF) ? "off" : "on",
           (clkslow & S3C2410_CLKSLOW_UCLK_OFF) ? "off" : "on");

    s3c_pwmclk_init();
    return 0;
}