/*
 * Common code for SoCs starting with the S3C2443
 *
 * Copyright (c) 2007, 2010 Simtec Electronics
 *      Ben Dooks <ben@simtec.co.uk>
 *
 * 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.
 */

#include <linux/init.h>
#include <linux/clk.h>
#include <linux/io.h>

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

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

#include <plat/cpu-freq.h>


static int s3c2443_gate(void __iomem *reg, struct clk *clk, int enable)
{
        u32 ctrlbit = clk->ctrlbit;
        u32 con = __raw_readl(reg);

        if (enable)
                con |= ctrlbit;
        else
                con &= ~ctrlbit;

        __raw_writel(con, reg);
        return 0;
}

int s3c2443_clkcon_enable_h(struct clk *clk, int enable)
{
        return s3c2443_gate(S3C2443_HCLKCON, clk, enable);
}

int s3c2443_clkcon_enable_p(struct clk *clk, int enable)
{
        return s3c2443_gate(S3C2443_PCLKCON, clk, enable);
}

int s3c2443_clkcon_enable_s(struct clk *clk, int enable)
{
        return s3c2443_gate(S3C2443_SCLKCON, clk, enable);
}

/* mpllref is a direct descendant of clk_xtal by default, but it is not
 * elided as the EPLL can be either sourced by the XTAL or EXTCLK and as
 * such directly equating the two source clocks is impossible.
 */
static struct clk clk_mpllref = {
        .name           = "mpllref",
        .parent         = &clk_xtal,
};

static struct clk *clk_epllref_sources[] = {
        [0] = &clk_mpllref,
        [1] = &clk_mpllref,
        [2] = &clk_xtal,
        [3] = &clk_ext,
};

struct clksrc_clk clk_epllref = {
        .clk    = {
                .name           = "epllref",
        },
        .sources = &(struct clksrc_sources) {
                .sources = clk_epllref_sources,
                .nr_sources = ARRAY_SIZE(clk_epllref_sources),
        },
        .reg_src = { .reg = S3C2443_CLKSRC, .size = 2, .shift = 7 },
};

/* esysclk
 *
 * this is sourced from either the EPLL or the EPLLref clock
*/

static struct clk *clk_sysclk_sources[] = {
        [0] = &clk_epllref.clk,
        [1] = &clk_epll,
};

struct clksrc_clk clk_esysclk = {
        .clk    = {
                .name           = "esysclk",
                .parent         = &clk_epll,
        },
        .sources = &(struct clksrc_sources) {
                .sources = clk_sysclk_sources,
                .nr_sources = ARRAY_SIZE(clk_sysclk_sources),
        },
        .reg_src = { .reg = S3C2443_CLKSRC, .size = 1, .shift = 6 },
};

static unsigned long s3c2443_getrate_mdivclk(struct clk *clk)
{
        unsigned long parent_rate = clk_get_rate(clk->parent);
        unsigned long div = __raw_readl(S3C2443_CLKDIV0);

        div  &= S3C2443_CLKDIV0_EXTDIV_MASK;
        div >>= (S3C2443_CLKDIV0_EXTDIV_SHIFT-1);       /* x2 */

        return parent_rate / (div + 1);
}

static struct clk clk_mdivclk = {
        .name           = "mdivclk",
        .parent         = &clk_mpllref,
        .ops            = &(struct clk_ops) {
                .get_rate       = s3c2443_getrate_mdivclk,
        },
};

static struct clk *clk_msysclk_sources[] = {
        [0] = &clk_mpllref,
        [1] = &clk_mpll,
        [2] = &clk_mdivclk,
        [3] = &clk_mpllref,
};

static struct clksrc_clk clk_msysclk = {
        .clk    = {
                .name           = "msysclk",
                .parent         = &clk_xtal,
        },
        .sources = &(struct clksrc_sources) {
                .sources = clk_msysclk_sources,
                .nr_sources = ARRAY_SIZE(clk_msysclk_sources),
        },
        .reg_src = { .reg = S3C2443_CLKSRC, .size = 2, .shift = 3 },
};

/* prediv
 *
 * this divides the msysclk down to pass to h/p/etc.
 */

static unsigned long s3c2443_prediv_getrate(struct clk *clk)
{
        unsigned long rate = clk_get_rate(clk->parent);
        unsigned long clkdiv0 = __raw_readl(S3C2443_CLKDIV0);

        clkdiv0 &= S3C2443_CLKDIV0_PREDIV_MASK;
        clkdiv0 >>= S3C2443_CLKDIV0_PREDIV_SHIFT;

        return rate / (clkdiv0 + 1);
}

static struct clk clk_prediv = {
        .name           = "prediv",
        .parent         = &clk_msysclk.clk,
        .ops            = &(struct clk_ops) {
                .get_rate       = s3c2443_prediv_getrate,
        },
};

/* hclk divider
 *
 * divides the prediv and provides the hclk.
 */

static unsigned long s3c2443_hclkdiv_getrate(struct clk *clk)
{
        unsigned long rate = clk_get_rate(clk->parent);
        unsigned long clkdiv0 = __raw_readl(S3C2443_CLKDIV0);

        clkdiv0 &= S3C2443_CLKDIV0_HCLKDIV_MASK;

        return rate / (clkdiv0 + 1);
}

static struct clk_ops clk_h_ops = {
        .get_rate       = s3c2443_hclkdiv_getrate,
};

/* pclk divider
 *
 * divides the hclk and provides the pclk.
 */

static unsigned long s3c2443_pclkdiv_getrate(struct clk *clk)
{
        unsigned long rate = clk_get_rate(clk->parent);
        unsigned long clkdiv0 = __raw_readl(S3C2443_CLKDIV0);

        clkdiv0 = ((clkdiv0 & S3C2443_CLKDIV0_HALF_PCLK) ? 1 : 0);

        return rate / (clkdiv0 + 1);
}

static struct clk_ops clk_p_ops = {
        .get_rate       = s3c2443_pclkdiv_getrate,
};

/* armdiv
 *
 * this clock is sourced from msysclk and can have a number of
 * divider values applied to it to then be fed into armclk.
*/

static unsigned int *armdiv;
static int nr_armdiv;
static int armdivmask;

static unsigned long s3c2443_armclk_roundrate(struct clk *clk,
                                              unsigned long rate)
{
        unsigned long parent = clk_get_rate(clk->parent);
        unsigned long calc;
        unsigned best = 256; /* bigger than any value */
        unsigned div;
        int ptr;

        if (!nr_armdiv)
                return -EINVAL;

        for (ptr = 0; ptr < nr_armdiv; ptr++) {
                div = armdiv[ptr];
                if (div) {
                        /* cpufreq provides 266mhz as 266666000 not 266666666 */
                        calc = (parent / div / 1000) * 1000;
                        if (calc <= rate && div < best)
                                best = div;
                }
        }

        return parent / best;
}

static unsigned long s3c2443_armclk_getrate(struct clk *clk)
{
        unsigned long rate = clk_get_rate(clk->parent);
        unsigned long clkcon0;
        int val;

        if (!nr_armdiv || !armdivmask)
                return -EINVAL;

        clkcon0 = __raw_readl(S3C2443_CLKDIV0);
        clkcon0 &= armdivmask;
        val = clkcon0 >> S3C2443_CLKDIV0_ARMDIV_SHIFT;

        return rate / armdiv[val];
}

static int s3c2443_armclk_setrate(struct clk *clk, unsigned long rate)
{
        unsigned long parent = clk_get_rate(clk->parent);
        unsigned long calc;
        unsigned div;
        unsigned best = 256; /* bigger than any value */
        int ptr;
        int val = -1;

        if (!nr_armdiv || !armdivmask)
                return -EINVAL;

        for (ptr = 0; ptr < nr_armdiv; ptr++) {
                div = armdiv[ptr];
                if (div) {
                        /* cpufreq provides 266mhz as 266666000 not 266666666 */
                        calc = (parent / div / 1000) * 1000;
                        if (calc <= rate && div < best) {
                                best = div;
                                val = ptr;
                        }
                }
        }

        if (val >= 0) {
                unsigned long clkcon0;

                clkcon0 = __raw_readl(S3C2443_CLKDIV0);
                clkcon0 &= ~armdivmask;
                clkcon0 |= val << S3C2443_CLKDIV0_ARMDIV_SHIFT;
                __raw_writel(clkcon0, S3C2443_CLKDIV0);
        }

        return (val == -1) ? -EINVAL : 0;
}

static struct clk clk_armdiv = {
        .name           = "armdiv",
        .parent         = &clk_msysclk.clk,
        .ops            = &(struct clk_ops) {
                .round_rate = s3c2443_armclk_roundrate,
                .get_rate = s3c2443_armclk_getrate,
                .set_rate = s3c2443_armclk_setrate,
        },
};

/* armclk
 *
 * this is the clock fed into the ARM core itself, from armdiv or from hclk.
 */

static struct clk *clk_arm_sources[] = {
        [0] = &clk_armdiv,
        [1] = &clk_h,
};

static struct clksrc_clk clk_arm = {
        .clk    = {
                .name           = "armclk",
        },
        .sources = &(struct clksrc_sources) {
                .sources = clk_arm_sources,
                .nr_sources = ARRAY_SIZE(clk_arm_sources),
        },
        .reg_src = { .reg = S3C2443_CLKDIV0, .size = 1, .shift = 13 },
};

/* usbhost
 *
 * usb host bus-clock, usually 48MHz to provide USB bus clock timing
*/

static struct clksrc_clk clk_usb_bus_host = {
        .clk    = {
                .name           = "usb-bus-host-parent",
                .parent         = &clk_esysclk.clk,
                .ctrlbit        = S3C2443_SCLKCON_USBHOST,
                .enable         = s3c2443_clkcon_enable_s,
        },
        .reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 4 },
};

/* common clksrc clocks */

static struct clksrc_clk clksrc_clks[] = {
        {
                /* camera interface bus-clock, divided down from esysclk */
                .clk    = {
                        .name           = "camif-upll", /* same as 2440 name */
                        .parent         = &clk_esysclk.clk,
                        .ctrlbit        = S3C2443_SCLKCON_CAMCLK,
                        .enable         = s3c2443_clkcon_enable_s,
                },
                .reg_div = { .reg = S3C2443_CLKDIV1, .size = 4, .shift = 26 },
        }, {
                .clk    = {
                        .name           = "display-if",
                        .parent         = &clk_esysclk.clk,
                        .ctrlbit        = S3C2443_SCLKCON_DISPCLK,
                        .enable         = s3c2443_clkcon_enable_s,
                },
                .reg_div = { .reg = S3C2443_CLKDIV1, .size = 8, .shift = 16 },
        },
};

static struct clksrc_clk clk_esys_uart = {
        /* ART baud-rate clock sourced from esysclk via a divisor */
        .clk    = {
                .name           = "uartclk",
                .parent         = &clk_esysclk.clk,
        },
        .reg_div = { .reg = S3C2443_CLKDIV1, .size = 4, .shift = 8 },
};

static struct clk clk_i2s_ext = {
        .name           = "i2s-ext",
};

/* i2s_eplldiv
 *
 * This clock is the output from the I2S divisor of ESYSCLK, and is separate
 * from the mux that comes after it (cannot merge into one single clock)
*/

static struct clksrc_clk clk_i2s_eplldiv = {
        .clk    = {
                .name           = "i2s-eplldiv",
                .parent         = &clk_esysclk.clk,
        },
        .reg_div = { .reg = S3C2443_CLKDIV1, .size = 4, .shift = 12, },
};

/* i2s-ref
 *
 * i2s bus reference clock, selectable from external, esysclk or epllref
 *
 * Note, this used to be two clocks, but was compressed into one.
*/

static struct clk *clk_i2s_srclist[] = {
        [0] = &clk_i2s_eplldiv.clk,
        [1] = &clk_i2s_ext,
        [2] = &clk_epllref.clk,
        [3] = &clk_epllref.clk,
};

static struct clksrc_clk clk_i2s = {
        .clk    = {
                .name           = "i2s-if",
                .ctrlbit        = S3C2443_SCLKCON_I2SCLK,
                .enable         = s3c2443_clkcon_enable_s,

        },
        .sources = &(struct clksrc_sources) {
                .sources = clk_i2s_srclist,
                .nr_sources = ARRAY_SIZE(clk_i2s_srclist),
        },
        .reg_src = { .reg = S3C2443_CLKSRC, .size = 2, .shift = 14 },
};

static struct clk init_clocks_off[] = {
        {
                .name           = "iis",
                .parent         = &clk_p,
                .enable         = s3c2443_clkcon_enable_p,
                .ctrlbit        = S3C2443_PCLKCON_IIS,
        }, {
                .name           = "adc",
                .parent         = &clk_p,
                .enable         = s3c2443_clkcon_enable_p,
                .ctrlbit        = S3C2443_PCLKCON_ADC,
        }, {
                .name           = "i2c",
                .parent         = &clk_p,
                .enable         = s3c2443_clkcon_enable_p,
                .ctrlbit        = S3C2443_PCLKCON_IIC,
        }
};

static struct clk init_clocks[] = {
        {
                .name           = "dma",
                .parent         = &clk_h,
                .enable         = s3c2443_clkcon_enable_h,
                .ctrlbit        = S3C2443_HCLKCON_DMA0,
        }, {
                .name           = "dma",
                .parent         = &clk_h,
                .enable         = s3c2443_clkcon_enable_h,
                .ctrlbit        = S3C2443_HCLKCON_DMA1,
        }, {
                .name           = "dma",
                .parent         = &clk_h,
                .enable         = s3c2443_clkcon_enable_h,
                .ctrlbit        = S3C2443_HCLKCON_DMA2,
        }, {
                .name           = "dma",
                .parent         = &clk_h,
                .enable         = s3c2443_clkcon_enable_h,
                .ctrlbit        = S3C2443_HCLKCON_DMA3,
        }, {
                .name           = "dma",
                .parent         = &clk_h,
                .enable         = s3c2443_clkcon_enable_h,
                .ctrlbit        = S3C2443_HCLKCON_DMA4,
        }, {
                .name           = "dma",
                .parent         = &clk_h,
                .enable         = s3c2443_clkcon_enable_h,
                .ctrlbit        = S3C2443_HCLKCON_DMA5,
        }, {
                .name           = "gpio",
                .parent         = &clk_p,
                .enable         = s3c2443_clkcon_enable_p,
                .ctrlbit        = S3C2443_PCLKCON_GPIO,
        }, {
                .name           = "usb-host",
                .parent         = &clk_h,
                .enable         = s3c2443_clkcon_enable_h,
                .ctrlbit        = S3C2443_HCLKCON_USBH,
        }, {
                .name           = "usb-device",
                .parent         = &clk_h,
                .enable         = s3c2443_clkcon_enable_h,
                .ctrlbit        = S3C2443_HCLKCON_USBD,
        }, {
                .name           = "lcd",
                .parent         = &clk_h,
                .enable         = s3c2443_clkcon_enable_h,
                .ctrlbit        = S3C2443_HCLKCON_LCDC,

        }, {
                .name           = "timers",
                .parent         = &clk_p,
                .enable         = s3c2443_clkcon_enable_p,
                .ctrlbit        = S3C2443_PCLKCON_PWMT,
        }, {
                .name           = "cfc",
                .parent         = &clk_h,
                .enable         = s3c2443_clkcon_enable_h,
                .ctrlbit        = S3C2443_HCLKCON_CFC,
        }, {
                .name           = "ssmc",
                .parent         = &clk_h,
                .enable         = s3c2443_clkcon_enable_h,
                .ctrlbit        = S3C2443_HCLKCON_SSMC,
        }, {
                .name           = "uart",
                .devname        = "s3c2440-uart.0",
                .parent         = &clk_p,
                .enable         = s3c2443_clkcon_enable_p,
                .ctrlbit        = S3C2443_PCLKCON_UART0,
        }, {
                .name           = "uart",
                .devname        = "s3c2440-uart.1",
                .parent         = &clk_p,
                .enable         = s3c2443_clkcon_enable_p,
                .ctrlbit        = S3C2443_PCLKCON_UART1,
        }, {
                .name           = "uart",
                .devname        = "s3c2440-uart.2",
                .parent         = &clk_p,
                .enable         = s3c2443_clkcon_enable_p,
                .ctrlbit        = S3C2443_PCLKCON_UART2,
        }, {
                .name           = "uart",
                .devname        = "s3c2440-uart.3",
                .parent         = &clk_p,
                .enable         = s3c2443_clkcon_enable_p,
                .ctrlbit        = S3C2443_PCLKCON_UART3,
        }, {
                .name           = "rtc",
                .parent         = &clk_p,
                .enable         = s3c2443_clkcon_enable_p,
                .ctrlbit        = S3C2443_PCLKCON_RTC,
        }, {
                .name           = "watchdog",
                .parent         = &clk_p,
                .ctrlbit        = S3C2443_PCLKCON_WDT,
        }, {
                .name           = "ac97",
                .parent         = &clk_p,
                .ctrlbit        = S3C2443_PCLKCON_AC97,
        }, {
                .name           = "nand",
                .parent         = &clk_h,
        }, {
                .name           = "usb-bus-host",
                .parent         = &clk_usb_bus_host.clk,
        }
};

static struct clk hsmmc1_clk = {
        .name           = "hsmmc",
        .devname        = "s3c-sdhci.1",
        .parent         = &clk_h,
        .enable         = s3c2443_clkcon_enable_h,
        .ctrlbit        = S3C2443_HCLKCON_HSMMC,
};

static struct clk hsspi_clk = {
        .name           = "spi",
        .devname        = "s3c2443-spi.0",
        .parent         = &clk_p,
        .enable         = s3c2443_clkcon_enable_p,
        .ctrlbit        = S3C2443_PCLKCON_HSSPI,
};

/* EPLLCON compatible enough to get on/off information */

void __init_or_cpufreq s3c2443_common_setup_clocks(pll_fn get_mpll)
{
        unsigned long epllcon = __raw_readl(S3C2443_EPLLCON);
        unsigned long mpllcon = __raw_readl(S3C2443_MPLLCON);
        struct clk *xtal_clk;
        unsigned long xtal;
        unsigned long pll;
        int ptr;

        xtal_clk = clk_get(NULL, "xtal");
        xtal = clk_get_rate(xtal_clk);
        clk_put(xtal_clk);

        pll = get_mpll(mpllcon, xtal);
        clk_msysclk.clk.rate = pll;
        clk_mpll.rate = pll;

        printk("CPU: MPLL %s %ld.%03ld MHz, cpu %ld.%03ld MHz, mem %ld.%03ld MHz, pclk %ld.%03ld MHz\n",
               (mpllcon & S3C2443_PLLCON_OFF) ? "off" : "on",
               print_mhz(pll), print_mhz(clk_get_rate(&clk_armdiv)),
               print_mhz(clk_get_rate(&clk_h)),
               print_mhz(clk_get_rate(&clk_p)));

        for (ptr = 0; ptr < ARRAY_SIZE(clksrc_clks); ptr++)
                s3c_set_clksrc(&clksrc_clks[ptr], true);

        /* ensure usb bus clock is within correct rate of 48MHz */

        if (clk_get_rate(&clk_usb_bus_host.clk) != (48 * 1000 * 1000)) {
                printk(KERN_INFO "Warning: USB host bus not at 48MHz\n");
                clk_set_rate(&clk_usb_bus_host.clk, 48*1000*1000);
        }

        printk("CPU: EPLL %s %ld.%03ld MHz, usb-bus %ld.%03ld MHz\n",
               (epllcon & S3C2443_PLLCON_OFF) ? "off" : "on",
               print_mhz(clk_get_rate(&clk_epll)),
               print_mhz(clk_get_rate(&clk_usb_bus)));
}

static struct clk *clks[] __initdata = {
        &clk_prediv,
        &clk_mpllref,
        &clk_mdivclk,
        &clk_ext,
        &clk_epll,
        &clk_usb_bus,
        &clk_armdiv,
        &hsmmc1_clk,
        &hsspi_clk,
};

static struct clksrc_clk *clksrcs[] __initdata = {
        &clk_i2s_eplldiv,
        &clk_i2s,
        &clk_usb_bus_host,
        &clk_epllref,
        &clk_esysclk,
        &clk_msysclk,
        &clk_arm,
};

static struct clk_lookup s3c2443_clk_lookup[] = {
        CLKDEV_INIT(NULL, "clk_uart_baud1", &s3c24xx_uclk),
        CLKDEV_INIT(NULL, "clk_uart_baud2", &clk_p),
        CLKDEV_INIT(NULL, "clk_uart_baud3", &clk_esys_uart.clk),
        CLKDEV_INIT("s3c-sdhci.1", "mmc_busclk.0", &hsmmc1_clk),
        CLKDEV_INIT("s3c2443-spi.0", "spi_busclk0", &hsspi_clk),
};

void __init s3c2443_common_init_clocks(int xtal, pll_fn get_mpll,
                                       unsigned int *divs, int nr_divs,
                                       int divmask)
{
        int ptr;

        armdiv = divs;
        nr_armdiv = nr_divs;
        armdivmask = divmask;

        /* s3c2443 parents h clock from prediv */
        clk_h.parent = &clk_prediv;
        clk_h.ops = &clk_h_ops;

        /* and p clock from h clock */
        clk_p.parent = &clk_h;
        clk_p.ops = &clk_p_ops;

        clk_usb_bus.parent = &clk_usb_bus_host.clk;
        clk_epll.parent = &clk_epllref.clk;

        s3c24xx_register_baseclocks(xtal);
        s3c24xx_register_clocks(clks, ARRAY_SIZE(clks));

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

        s3c_register_clksrc(clksrc_clks, ARRAY_SIZE(clksrc_clks));
        s3c_register_clocks(init_clocks, ARRAY_SIZE(init_clocks));

        /* See s3c2443/etc notes on disabling clocks at init time */
        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));

        s3c2443_common_setup_clocks(get_mpll);
}