clock-s3c2443.c

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/* linux/arch/arm/mach-s3c2443/clock.c
 *
 * Copyright (c) 2007, 2010 Simtec Electronics
 *  Ben Dooks <[email protected]>
 *
 * S3C2443 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/serial_core.h>
#include <linux/io.h>

#include <asm/mach/map.h>

#include <mach/hardware.h>

#include <mach/regs-s3c2443-clock.h>

#include <plat/cpu-freq.h>

#include <plat/s3c2443.h>
#include <plat/clock.h>
#include <plat/clock-clksrc.h>
#include <plat/cpu.h>

/* We currently have to assume that the system is running
 * from the XTPll input, and that all ***REFCLKs are being
 * fed from it, as we cannot read the state of OM[4] from
 * software.
 *
 * It would be possible for each board initialisation to
 * set the correct muxing at initialisation
*/

/* clock selections */

/* armdiv
 *
 * this clock is sourced from msysclk and can have a number of
 * divider values applied to it to then be fed into armclk.
 * The real clock definition is done in s3c2443-clock.c,
 * only the armdiv divisor table must be defined here.
*/

static unsigned int armdiv[16] = {
    [S3C2443_CLKDIV0_ARMDIV_1 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]  = 1,
    [S3C2443_CLKDIV0_ARMDIV_2 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]  = 2,
    [S3C2443_CLKDIV0_ARMDIV_3 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]  = 3,
    [S3C2443_CLKDIV0_ARMDIV_4 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]  = 4,
    [S3C2443_CLKDIV0_ARMDIV_6 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]  = 6,
    [S3C2443_CLKDIV0_ARMDIV_8 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]  = 8,
    [S3C2443_CLKDIV0_ARMDIV_12 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 12,
    [S3C2443_CLKDIV0_ARMDIV_16 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 16,
};

/* hsspi
 *
 * high-speed spi clock, sourced from esysclk
*/

static struct clksrc_clk clk_hsspi = {
    .clk    = {
        .name       = "hsspi-if",
        .parent     = &clk_esysclk.clk,
        .ctrlbit    = S3C2443_SCLKCON_HSSPICLK,
        .enable     = s3c2443_clkcon_enable_s,
    },
    .reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 4 },
};


/* clk_hsmcc_div
 *
 * this clock is sourced from epll, and is fed through a divider,
 * to a mux controlled by sclkcon where either it or a extclk can
 * be fed to the hsmmc block
*/

static struct clksrc_clk clk_hsmmc_div = {
    .clk    = {
        .name       = "hsmmc-div",
        .devname    = "s3c-sdhci.1",
        .parent     = &clk_esysclk.clk,
    },
    .reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 6 },
};

static int s3c2443_setparent_hsmmc(struct clk *clk, struct clk *parent)
{
    unsigned long clksrc = __raw_readl(S3C2443_SCLKCON);

    clksrc &= ~(S3C2443_SCLKCON_HSMMCCLK_EXT |
            S3C2443_SCLKCON_HSMMCCLK_EPLL);

    if (parent == &clk_epll)
        clksrc |= S3C2443_SCLKCON_HSMMCCLK_EPLL;
    else if (parent == &clk_ext)
        clksrc |= S3C2443_SCLKCON_HSMMCCLK_EXT;
    else
        return -EINVAL;

    if (clk->usage > 0) {
        __raw_writel(clksrc, S3C2443_SCLKCON);
    }

    clk->parent = parent;
    return 0;
}

static int s3c2443_enable_hsmmc(struct clk *clk, int enable)
{
    return s3c2443_setparent_hsmmc(clk, clk->parent);
}

static struct clk clk_hsmmc = {
    .name       = "hsmmc-if",
    .devname    = "s3c-sdhci.1",
    .parent     = &clk_hsmmc_div.clk,
    .enable     = s3c2443_enable_hsmmc,
    .ops        = &(struct clk_ops) {
        .set_parent = s3c2443_setparent_hsmmc,
    },
};

/* standard clock definitions */

static struct clk init_clocks_off[] = {
    {
        .name       = "sdi",
        .parent     = &clk_p,
        .enable     = s3c2443_clkcon_enable_p,
        .ctrlbit    = S3C2443_PCLKCON_SDI,
    }, {
        .name       = "spi",
        .devname    = "s3c2410-spi.0",
        .parent     = &clk_p,
        .enable     = s3c2443_clkcon_enable_p,
        .ctrlbit    = S3C2443_PCLKCON_SPI0,
    }, {
        .name       = "spi",
        .devname    = "s3c2410-spi.1",
        .parent     = &clk_p,
        .enable     = s3c2443_clkcon_enable_p,
        .ctrlbit    = S3C2443_PCLKCON_SPI1,
    }
};

/* clocks to add straight away */

static struct clksrc_clk *clksrcs[] __initdata = {
    &clk_hsspi,
    &clk_hsmmc_div,
};

static struct clk *clks[] __initdata = {
    &clk_hsmmc,
};

static struct clk_lookup s3c2443_clk_lookup[] = {
    CLKDEV_INIT("s3c-sdhci.1", "mmc_busclk.2", &clk_hsmmc),
    CLKDEV_INIT("s3c2443-spi.0", "spi_busclk2", &clk_hsspi.clk),
};

void __init s3c2443_init_clocks(int xtal)
{
    unsigned long epllcon = __raw_readl(S3C2443_EPLLCON);
    int ptr;

    clk_epll.rate = s3c2443_get_epll(epllcon, xtal);
    clk_epll.parent = &clk_epllref.clk;

    s3c2443_common_init_clocks(xtal, s3c2443_get_mpll,
                   armdiv, ARRAY_SIZE(armdiv),
                   S3C2443_CLKDIV0_ARMDIV_MASK);

    s3c24xx_register_clocks(clks, ARRAY_SIZE(clks));

    for (ptr = 0; ptr < ARRAY_SIZE(clksrcs); ptr++)
        s3c_register_clksrc(clksrcs[ptr], 1);

    /* 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));
    clkdev_add_table(s3c2443_clk_lookup, ARRAY_SIZE(s3c2443_clk_lookup));

    s3c_pwmclk_init();
}