Merge branch 'for-rmk' of git://git.pengutronix.de/git/imx/linux-2.6 into devel-stable

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / arch / arm / mach-mx5 / clock-mx51.c

/*
 * Copyright 2008-2010 Freescale Semiconductor, Inc. All Rights Reserved.
 * Copyright (C) 2009-2010 Amit Kucheria <amit.kucheria@canonical.com>
 *
 * The code contained herein is licensed under the GNU General Public
 * License. You may obtain a copy of the GNU General Public License
 * Version 2 or later at the following locations:
 *
 * http://www.opensource.org/licenses/gpl-license.html
 * http://www.gnu.org/copyleft/gpl.html
 */

#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>

#include <asm/clkdev.h>
#include <asm/div64.h>

#include <mach/hardware.h>
#include <mach/common.h>
#include <mach/clock.h>

#include "crm_regs.h"

/* External clock values passed-in by the board code */
static unsigned long external_high_reference, external_low_reference;
static unsigned long oscillator_reference, ckih2_reference;

static struct clk osc_clk;
static struct clk pll1_main_clk;
static struct clk pll1_sw_clk;
static struct clk pll2_sw_clk;
static struct clk pll3_sw_clk;
static struct clk lp_apm_clk;
static struct clk periph_apm_clk;
static struct clk ahb_clk;
static struct clk ipg_clk;
static struct clk usboh3_clk;

#define MAX_DPLL_WAIT_TRIES     1000 /* 1000 * udelay(1) = 1ms */

static int _clk_ccgr_enable(struct clk *clk)
{
        u32 reg;

        reg = __raw_readl(clk->enable_reg);
        reg |= MXC_CCM_CCGRx_MOD_ON << clk->enable_shift;
        __raw_writel(reg, clk->enable_reg);

        return 0;
}

static void _clk_ccgr_disable(struct clk *clk)
{
        u32 reg;
        reg = __raw_readl(clk->enable_reg);
        reg &= ~(MXC_CCM_CCGRx_MOD_OFF << clk->enable_shift);
        __raw_writel(reg, clk->enable_reg);

}

static void _clk_ccgr_disable_inwait(struct clk *clk)
{
        u32 reg;

        reg = __raw_readl(clk->enable_reg);
        reg &= ~(MXC_CCM_CCGRx_CG_MASK << clk->enable_shift);
        reg |= MXC_CCM_CCGRx_MOD_IDLE << clk->enable_shift;
        __raw_writel(reg, clk->enable_reg);
}

/*
 * For the 4-to-1 muxed input clock
 */
static inline u32 _get_mux(struct clk *parent, struct clk *m0,
                           struct clk *m1, struct clk *m2, struct clk *m3)
{
        if (parent == m0)
                return 0;
        else if (parent == m1)
                return 1;
        else if (parent == m2)
                return 2;
        else if (parent == m3)
                return 3;
        else
                BUG();

        return -EINVAL;
}

static inline void __iomem *_get_pll_base(struct clk *pll)
{
        if (pll == &pll1_main_clk)
                return MX51_DPLL1_BASE;
        else if (pll == &pll2_sw_clk)
                return MX51_DPLL2_BASE;
        else if (pll == &pll3_sw_clk)
                return MX51_DPLL3_BASE;
        else
                BUG();

        return NULL;
}

static unsigned long clk_pll_get_rate(struct clk *clk)
{
        long mfi, mfn, mfd, pdf, ref_clk, mfn_abs;
        unsigned long dp_op, dp_mfd, dp_mfn, dp_ctl, pll_hfsm, dbl;
        void __iomem *pllbase;
        s64 temp;
        unsigned long parent_rate;

        parent_rate = clk_get_rate(clk->parent);

        pllbase = _get_pll_base(clk);

        dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL);
        pll_hfsm = dp_ctl & MXC_PLL_DP_CTL_HFSM;
        dbl = dp_ctl & MXC_PLL_DP_CTL_DPDCK0_2_EN;

        if (pll_hfsm == 0) {
                dp_op = __raw_readl(pllbase + MXC_PLL_DP_OP);
                dp_mfd = __raw_readl(pllbase + MXC_PLL_DP_MFD);
                dp_mfn = __raw_readl(pllbase + MXC_PLL_DP_MFN);
        } else {
                dp_op = __raw_readl(pllbase + MXC_PLL_DP_HFS_OP);
                dp_mfd = __raw_readl(pllbase + MXC_PLL_DP_HFS_MFD);
                dp_mfn = __raw_readl(pllbase + MXC_PLL_DP_HFS_MFN);
        }
        pdf = dp_op & MXC_PLL_DP_OP_PDF_MASK;
        mfi = (dp_op & MXC_PLL_DP_OP_MFI_MASK) >> MXC_PLL_DP_OP_MFI_OFFSET;
        mfi = (mfi <= 5) ? 5 : mfi;
        mfd = dp_mfd & MXC_PLL_DP_MFD_MASK;
        mfn = mfn_abs = dp_mfn & MXC_PLL_DP_MFN_MASK;
        /* Sign extend to 32-bits */
        if (mfn >= 0x04000000) {
                mfn |= 0xFC000000;
                mfn_abs = -mfn;
        }

        ref_clk = 2 * parent_rate;
        if (dbl != 0)
                ref_clk *= 2;

        ref_clk /= (pdf + 1);
        temp = (u64) ref_clk * mfn_abs;
        do_div(temp, mfd + 1);
        if (mfn < 0)
                temp = -temp;
        temp = (ref_clk * mfi) + temp;

        return temp;
}

static int _clk_pll_set_rate(struct clk *clk, unsigned long rate)
{
        u32 reg;
        void __iomem *pllbase;

        long mfi, pdf, mfn, mfd = 999999;
        s64 temp64;
        unsigned long quad_parent_rate;
        unsigned long pll_hfsm, dp_ctl;
        unsigned long parent_rate;

        parent_rate = clk_get_rate(clk->parent);

        pllbase = _get_pll_base(clk);

        quad_parent_rate = 4 * parent_rate;
        pdf = mfi = -1;
        while (++pdf < 16 && mfi < 5)
                mfi = rate * (pdf+1) / quad_parent_rate;
        if (mfi > 15)
                return -EINVAL;
        pdf--;

        temp64 = rate * (pdf+1) - quad_parent_rate * mfi;
        do_div(temp64, quad_parent_rate/1000000);
        mfn = (long)temp64;

        dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL);
        /* use dpdck0_2 */
        __raw_writel(dp_ctl | 0x1000L, pllbase + MXC_PLL_DP_CTL);
        pll_hfsm = dp_ctl & MXC_PLL_DP_CTL_HFSM;
        if (pll_hfsm == 0) {
                reg = mfi << 4 | pdf;
                __raw_writel(reg, pllbase + MXC_PLL_DP_OP);
                __raw_writel(mfd, pllbase + MXC_PLL_DP_MFD);
                __raw_writel(mfn, pllbase + MXC_PLL_DP_MFN);
        } else {
                reg = mfi << 4 | pdf;
                __raw_writel(reg, pllbase + MXC_PLL_DP_HFS_OP);
                __raw_writel(mfd, pllbase + MXC_PLL_DP_HFS_MFD);
                __raw_writel(mfn, pllbase + MXC_PLL_DP_HFS_MFN);
        }

        return 0;
}

static int _clk_pll_enable(struct clk *clk)
{
        u32 reg;
        void __iomem *pllbase;
        int i = 0;

        pllbase = _get_pll_base(clk);
        reg = __raw_readl(pllbase + MXC_PLL_DP_CTL) | MXC_PLL_DP_CTL_UPEN;
        __raw_writel(reg, pllbase + MXC_PLL_DP_CTL);

        /* Wait for lock */
        do {
                reg = __raw_readl(pllbase + MXC_PLL_DP_CTL);
                if (reg & MXC_PLL_DP_CTL_LRF)
                        break;

                udelay(1);
        } while (++i < MAX_DPLL_WAIT_TRIES);

        if (i == MAX_DPLL_WAIT_TRIES) {
                pr_err("MX5: pll locking failed\n");
                return -EINVAL;
        }

        return 0;
}

static void _clk_pll_disable(struct clk *clk)
{
        u32 reg;
        void __iomem *pllbase;

        pllbase = _get_pll_base(clk);
        reg = __raw_readl(pllbase + MXC_PLL_DP_CTL) & ~MXC_PLL_DP_CTL_UPEN;
        __raw_writel(reg, pllbase + MXC_PLL_DP_CTL);
}

static int _clk_pll1_sw_set_parent(struct clk *clk, struct clk *parent)
{
        u32 reg, step;

        reg = __raw_readl(MXC_CCM_CCSR);

        /* When switching from pll_main_clk to a bypass clock, first select a
         * multiplexed clock in 'step_sel', then shift the glitchless mux
         * 'pll1_sw_clk_sel'.
         *
         * When switching back, do it in reverse order
         */
        if (parent == &pll1_main_clk) {
                /* Switch to pll1_main_clk */
                reg &= ~MXC_CCM_CCSR_PLL1_SW_CLK_SEL;
                __raw_writel(reg, MXC_CCM_CCSR);
                /* step_clk mux switched to lp_apm, to save power. */
                reg = __raw_readl(MXC_CCM_CCSR);
                reg &= ~MXC_CCM_CCSR_STEP_SEL_MASK;
                reg |= (MXC_CCM_CCSR_STEP_SEL_LP_APM <<
                                MXC_CCM_CCSR_STEP_SEL_OFFSET);
        } else {
                if (parent == &lp_apm_clk) {
                        step = MXC_CCM_CCSR_STEP_SEL_LP_APM;
                } else  if (parent == &pll2_sw_clk) {
                        step = MXC_CCM_CCSR_STEP_SEL_PLL2_DIVIDED;
                } else  if (parent == &pll3_sw_clk) {
                        step = MXC_CCM_CCSR_STEP_SEL_PLL3_DIVIDED;
                } else
                        return -EINVAL;

                reg &= ~MXC_CCM_CCSR_STEP_SEL_MASK;
                reg |= (step << MXC_CCM_CCSR_STEP_SEL_OFFSET);

                __raw_writel(reg, MXC_CCM_CCSR);
                /* Switch to step_clk */
                reg = __raw_readl(MXC_CCM_CCSR);
                reg |= MXC_CCM_CCSR_PLL1_SW_CLK_SEL;
        }
        __raw_writel(reg, MXC_CCM_CCSR);
        return 0;
}

static unsigned long clk_pll1_sw_get_rate(struct clk *clk)
{
        u32 reg, div;
        unsigned long parent_rate;

        parent_rate = clk_get_rate(clk->parent);

        reg = __raw_readl(MXC_CCM_CCSR);

        if (clk->parent == &pll2_sw_clk) {
                div = ((reg & MXC_CCM_CCSR_PLL2_PODF_MASK) >>
                       MXC_CCM_CCSR_PLL2_PODF_OFFSET) + 1;
        } else if (clk->parent == &pll3_sw_clk) {
                div = ((reg & MXC_CCM_CCSR_PLL3_PODF_MASK) >>
                       MXC_CCM_CCSR_PLL3_PODF_OFFSET) + 1;
        } else
                div = 1;
        return parent_rate / div;
}

static int _clk_pll2_sw_set_parent(struct clk *clk, struct clk *parent)
{
        u32 reg;

        reg = __raw_readl(MXC_CCM_CCSR);

        if (parent == &pll2_sw_clk)
                reg &= ~MXC_CCM_CCSR_PLL2_SW_CLK_SEL;
        else
                reg |= MXC_CCM_CCSR_PLL2_SW_CLK_SEL;

        __raw_writel(reg, MXC_CCM_CCSR);
        return 0;
}

static int _clk_lp_apm_set_parent(struct clk *clk, struct clk *parent)
{
        u32 reg;

        if (parent == &osc_clk)
                reg = __raw_readl(MXC_CCM_CCSR) & ~MXC_CCM_CCSR_LP_APM_SEL;
        else
                return -EINVAL;

        __raw_writel(reg, MXC_CCM_CCSR);

        return 0;
}

static unsigned long clk_arm_get_rate(struct clk *clk)
{
        u32 cacrr, div;
        unsigned long parent_rate;

        parent_rate = clk_get_rate(clk->parent);
        cacrr = __raw_readl(MXC_CCM_CACRR);
        div = (cacrr & MXC_CCM_CACRR_ARM_PODF_MASK) + 1;

        return parent_rate / div;
}

static int _clk_periph_apm_set_parent(struct clk *clk, struct clk *parent)
{
        u32 reg, mux;
        int i = 0;

        mux = _get_mux(parent, &pll1_sw_clk, &pll3_sw_clk, &lp_apm_clk, NULL);

        reg = __raw_readl(MXC_CCM_CBCMR) & ~MXC_CCM_CBCMR_PERIPH_CLK_SEL_MASK;
        reg |= mux << MXC_CCM_CBCMR_PERIPH_CLK_SEL_OFFSET;
        __raw_writel(reg, MXC_CCM_CBCMR);

        /* Wait for lock */
        do {
                reg = __raw_readl(MXC_CCM_CDHIPR);
                if (!(reg &  MXC_CCM_CDHIPR_PERIPH_CLK_SEL_BUSY))
                        break;

                udelay(1);
        } while (++i < MAX_DPLL_WAIT_TRIES);

        if (i == MAX_DPLL_WAIT_TRIES) {
                pr_err("MX5: Set parent for periph_apm clock failed\n");
                return -EINVAL;
        }

        return 0;
}

static int _clk_main_bus_set_parent(struct clk *clk, struct clk *parent)
{
        u32 reg;

        reg = __raw_readl(MXC_CCM_CBCDR);

        if (parent == &pll2_sw_clk)
                reg &= ~MXC_CCM_CBCDR_PERIPH_CLK_SEL;
        else if (parent == &periph_apm_clk)
                reg |= MXC_CCM_CBCDR_PERIPH_CLK_SEL;
        else
                return -EINVAL;

        __raw_writel(reg, MXC_CCM_CBCDR);

        return 0;
}

static struct clk main_bus_clk = {
        .parent = &pll2_sw_clk,
        .set_parent = _clk_main_bus_set_parent,
};

static unsigned long clk_ahb_get_rate(struct clk *clk)
{
        u32 reg, div;
        unsigned long parent_rate;

        parent_rate = clk_get_rate(clk->parent);

        reg = __raw_readl(MXC_CCM_CBCDR);
        div = ((reg & MXC_CCM_CBCDR_AHB_PODF_MASK) >>
               MXC_CCM_CBCDR_AHB_PODF_OFFSET) + 1;
        return parent_rate / div;
}


static int _clk_ahb_set_rate(struct clk *clk, unsigned long rate)
{
        u32 reg, div;
        unsigned long parent_rate;
        int i = 0;

        parent_rate = clk_get_rate(clk->parent);

        div = parent_rate / rate;
        if (div > 8 || div < 1 || ((parent_rate / div) != rate))
                return -EINVAL;

        reg = __raw_readl(MXC_CCM_CBCDR);
        reg &= ~MXC_CCM_CBCDR_AHB_PODF_MASK;
        reg |= (div - 1) << MXC_CCM_CBCDR_AHB_PODF_OFFSET;
        __raw_writel(reg, MXC_CCM_CBCDR);

        /* Wait for lock */
        do {
                reg = __raw_readl(MXC_CCM_CDHIPR);
                if (!(reg & MXC_CCM_CDHIPR_AHB_PODF_BUSY))
                        break;

                udelay(1);
        } while (++i < MAX_DPLL_WAIT_TRIES);

        if (i == MAX_DPLL_WAIT_TRIES) {
                pr_err("MX5: clk_ahb_set_rate failed\n");
                return -EINVAL;
        }

        return 0;
}

static unsigned long _clk_ahb_round_rate(struct clk *clk,
                                                unsigned long rate)
{
        u32 div;
        unsigned long parent_rate;

        parent_rate = clk_get_rate(clk->parent);

        div = parent_rate / rate;
        if (div > 8)
                div = 8;
        else if (div == 0)
                div++;
        return parent_rate / div;
}


static int _clk_max_enable(struct clk *clk)
{
        u32 reg;

        _clk_ccgr_enable(clk);

        /* Handshake with MAX when LPM is entered. */
        reg = __raw_readl(MXC_CCM_CLPCR);
        reg &= ~MXC_CCM_CLPCR_BYPASS_MAX_LPM_HS;
        __raw_writel(reg, MXC_CCM_CLPCR);

        return 0;
}

static void _clk_max_disable(struct clk *clk)
{
        u32 reg;

        _clk_ccgr_disable_inwait(clk);

        /* No Handshake with MAX when LPM is entered as its disabled. */
        reg = __raw_readl(MXC_CCM_CLPCR);
        reg |= MXC_CCM_CLPCR_BYPASS_MAX_LPM_HS;
        __raw_writel(reg, MXC_CCM_CLPCR);
}

static unsigned long clk_ipg_get_rate(struct clk *clk)
{
        u32 reg, div;
        unsigned long parent_rate;

        parent_rate = clk_get_rate(clk->parent);

        reg = __raw_readl(MXC_CCM_CBCDR);
        div = ((reg & MXC_CCM_CBCDR_IPG_PODF_MASK) >>
               MXC_CCM_CBCDR_IPG_PODF_OFFSET) + 1;

        return parent_rate / div;
}

static unsigned long clk_ipg_per_get_rate(struct clk *clk)
{
        u32 reg, prediv1, prediv2, podf;
        unsigned long parent_rate;

        parent_rate = clk_get_rate(clk->parent);

        if (clk->parent == &main_bus_clk || clk->parent == &lp_apm_clk) {
                /* the main_bus_clk is the one before the DVFS engine */
                reg = __raw_readl(MXC_CCM_CBCDR);
                prediv1 = ((reg & MXC_CCM_CBCDR_PERCLK_PRED1_MASK) >>
                           MXC_CCM_CBCDR_PERCLK_PRED1_OFFSET) + 1;
                prediv2 = ((reg & MXC_CCM_CBCDR_PERCLK_PRED2_MASK) >>
                           MXC_CCM_CBCDR_PERCLK_PRED2_OFFSET) + 1;
                podf = ((reg & MXC_CCM_CBCDR_PERCLK_PODF_MASK) >>
                        MXC_CCM_CBCDR_PERCLK_PODF_OFFSET) + 1;
                return parent_rate / (prediv1 * prediv2 * podf);
        } else if (clk->parent == &ipg_clk)
                return parent_rate;
        else
                BUG();
}

static int _clk_ipg_per_set_parent(struct clk *clk, struct clk *parent)
{
        u32 reg;

        reg = __raw_readl(MXC_CCM_CBCMR);

        reg &= ~MXC_CCM_CBCMR_PERCLK_LP_APM_CLK_SEL;
        reg &= ~MXC_CCM_CBCMR_PERCLK_IPG_CLK_SEL;

        if (parent == &ipg_clk)
                reg |= MXC_CCM_CBCMR_PERCLK_IPG_CLK_SEL;
        else if (parent == &lp_apm_clk)
                reg |= MXC_CCM_CBCMR_PERCLK_LP_APM_CLK_SEL;
        else if (parent != &main_bus_clk)
                return -EINVAL;

        __raw_writel(reg, MXC_CCM_CBCMR);

        return 0;
}

static unsigned long clk_uart_get_rate(struct clk *clk)
{
        u32 reg, prediv, podf;
        unsigned long parent_rate;

        parent_rate = clk_get_rate(clk->parent);

        reg = __raw_readl(MXC_CCM_CSCDR1);
        prediv = ((reg & MXC_CCM_CSCDR1_UART_CLK_PRED_MASK) >>
                  MXC_CCM_CSCDR1_UART_CLK_PRED_OFFSET) + 1;
        podf = ((reg & MXC_CCM_CSCDR1_UART_CLK_PODF_MASK) >>
                MXC_CCM_CSCDR1_UART_CLK_PODF_OFFSET) + 1;

        return parent_rate / (prediv * podf);
}

static int _clk_uart_set_parent(struct clk *clk, struct clk *parent)
{
        u32 reg, mux;

        mux = _get_mux(parent, &pll1_sw_clk, &pll2_sw_clk, &pll3_sw_clk,
                       &lp_apm_clk);
        reg = __raw_readl(MXC_CCM_CSCMR1) & ~MXC_CCM_CSCMR1_UART_CLK_SEL_MASK;
        reg |= mux << MXC_CCM_CSCMR1_UART_CLK_SEL_OFFSET;
        __raw_writel(reg, MXC_CCM_CSCMR1);

        return 0;
}

static unsigned long clk_usboh3_get_rate(struct clk *clk)
{
        u32 reg, prediv, podf;
        unsigned long parent_rate;

        parent_rate = clk_get_rate(clk->parent);

        reg = __raw_readl(MXC_CCM_CSCDR1);
        prediv = ((reg & MXC_CCM_CSCDR1_USBOH3_CLK_PRED_MASK) >>
                  MXC_CCM_CSCDR1_USBOH3_CLK_PRED_OFFSET) + 1;
        podf = ((reg & MXC_CCM_CSCDR1_USBOH3_CLK_PODF_MASK) >>
                MXC_CCM_CSCDR1_USBOH3_CLK_PODF_OFFSET) + 1;

        return parent_rate / (prediv * podf);
}

static int _clk_usboh3_set_parent(struct clk *clk, struct clk *parent)
{
        u32 reg, mux;

        mux = _get_mux(parent, &pll1_sw_clk, &pll2_sw_clk, &pll3_sw_clk,
                       &lp_apm_clk);
        reg = __raw_readl(MXC_CCM_CSCMR1) & ~MXC_CCM_CSCMR1_USBOH3_CLK_SEL_MASK;
        reg |= mux << MXC_CCM_CSCMR1_USBOH3_CLK_SEL_OFFSET;
        __raw_writel(reg, MXC_CCM_CSCMR1);

        return 0;
}

static unsigned long get_high_reference_clock_rate(struct clk *clk)
{
        return external_high_reference;
}

static unsigned long get_low_reference_clock_rate(struct clk *clk)
{
        return external_low_reference;
}

static unsigned long get_oscillator_reference_clock_rate(struct clk *clk)
{
        return oscillator_reference;
}

static unsigned long get_ckih2_reference_clock_rate(struct clk *clk)
{
        return ckih2_reference;
}

/* External high frequency clock */
static struct clk ckih_clk = {
        .get_rate = get_high_reference_clock_rate,
};

static struct clk ckih2_clk = {
        .get_rate = get_ckih2_reference_clock_rate,
};

static struct clk osc_clk = {
        .get_rate = get_oscillator_reference_clock_rate,
};

/* External low frequency (32kHz) clock */
static struct clk ckil_clk = {
        .get_rate = get_low_reference_clock_rate,
};

static struct clk pll1_main_clk = {
        .parent = &osc_clk,
        .get_rate = clk_pll_get_rate,
        .enable = _clk_pll_enable,
        .disable = _clk_pll_disable,
};

/* Clock tree block diagram (WIP):
 *      CCM: Clock Controller Module
 *
 * PLL output -> |
 *               | CCM Switcher -> CCM_CLK_ROOT_GEN ->
 * PLL bypass -> |
 *
 */

/* PLL1 SW supplies to ARM core */
static struct clk pll1_sw_clk = {
        .parent = &pll1_main_clk,
        .set_parent = _clk_pll1_sw_set_parent,
        .get_rate = clk_pll1_sw_get_rate,
};

/* PLL2 SW supplies to AXI/AHB/IP buses */
static struct clk pll2_sw_clk = {
        .parent = &osc_clk,
        .get_rate = clk_pll_get_rate,
        .set_rate = _clk_pll_set_rate,
        .set_parent = _clk_pll2_sw_set_parent,
        .enable = _clk_pll_enable,
        .disable = _clk_pll_disable,
};

/* PLL3 SW supplies to serial clocks like USB, SSI, etc. */
static struct clk pll3_sw_clk = {
        .parent = &osc_clk,
        .set_rate = _clk_pll_set_rate,
        .get_rate = clk_pll_get_rate,
        .enable = _clk_pll_enable,
        .disable = _clk_pll_disable,
};

/* Low-power Audio Playback Mode clock */
static struct clk lp_apm_clk = {
        .parent = &osc_clk,
        .set_parent = _clk_lp_apm_set_parent,
};

static struct clk periph_apm_clk = {
        .parent = &pll1_sw_clk,
        .set_parent = _clk_periph_apm_set_parent,
};

static struct clk cpu_clk = {
        .parent = &pll1_sw_clk,
        .get_rate = clk_arm_get_rate,
};

static struct clk ahb_clk = {
        .parent = &main_bus_clk,
        .get_rate = clk_ahb_get_rate,
        .set_rate = _clk_ahb_set_rate,
        .round_rate = _clk_ahb_round_rate,
};

/* Main IP interface clock for access to registers */
static struct clk ipg_clk = {
        .parent = &ahb_clk,
        .get_rate = clk_ipg_get_rate,
};

static struct clk ipg_perclk = {
        .parent = &lp_apm_clk,
        .get_rate = clk_ipg_per_get_rate,
        .set_parent = _clk_ipg_per_set_parent,
};

static struct clk uart_root_clk = {
        .parent = &pll2_sw_clk,
        .get_rate = clk_uart_get_rate,
        .set_parent = _clk_uart_set_parent,
};

static struct clk usboh3_clk = {
        .parent = &pll2_sw_clk,
        .get_rate = clk_usboh3_get_rate,
        .set_parent = _clk_usboh3_set_parent,
};

static struct clk ahb_max_clk = {
        .parent = &ahb_clk,
        .enable_reg = MXC_CCM_CCGR0,
        .enable_shift = MXC_CCM_CCGRx_CG14_OFFSET,
        .enable = _clk_max_enable,
        .disable = _clk_max_disable,
};

static struct clk aips_tz1_clk = {
        .parent = &ahb_clk,
        .secondary = &ahb_max_clk,
        .enable_reg = MXC_CCM_CCGR0,
        .enable_shift = MXC_CCM_CCGRx_CG12_OFFSET,
        .enable = _clk_ccgr_enable,
        .disable = _clk_ccgr_disable_inwait,
};

static struct clk aips_tz2_clk = {
        .parent = &ahb_clk,
        .secondary = &ahb_max_clk,
        .enable_reg = MXC_CCM_CCGR0,
        .enable_shift = MXC_CCM_CCGRx_CG13_OFFSET,
        .enable = _clk_ccgr_enable,
        .disable = _clk_ccgr_disable_inwait,
};

static struct clk gpt_32k_clk = {
        .id = 0,
        .parent = &ckil_clk,
};

#define DEFINE_CLOCK(name, i, er, es, gr, sr, p, s)     \
        static struct clk name = {                      \
                .id             = i,                    \
                .enable_reg     = er,                   \
                .enable_shift   = es,                   \
                .get_rate       = gr,                   \
                .set_rate       = sr,                   \
                .enable         = _clk_ccgr_enable,     \
                .disable        = _clk_ccgr_disable,    \
                .parent         = p,                    \
                .secondary      = s,                    \
        }

/* DEFINE_CLOCK(name, id, enable_reg, enable_shift,
   get_rate, set_rate, parent, secondary); */

/* Shared peripheral bus arbiter */
DEFINE_CLOCK(spba_clk, 0, MXC_CCM_CCGR5, MXC_CCM_CCGRx_CG0_OFFSET,
        NULL,  NULL, &ipg_clk, NULL);

/* UART */
DEFINE_CLOCK(uart1_clk, 0, MXC_CCM_CCGR1, MXC_CCM_CCGRx_CG4_OFFSET,
        NULL,  NULL, &uart_root_clk, NULL);
DEFINE_CLOCK(uart2_clk, 1, MXC_CCM_CCGR1, MXC_CCM_CCGRx_CG6_OFFSET,
        NULL,  NULL, &uart_root_clk, NULL);
DEFINE_CLOCK(uart3_clk, 2, MXC_CCM_CCGR1, MXC_CCM_CCGRx_CG8_OFFSET,
        NULL,  NULL, &uart_root_clk, NULL);
DEFINE_CLOCK(uart1_ipg_clk, 0, MXC_CCM_CCGR1, MXC_CCM_CCGRx_CG3_OFFSET,
        NULL,  NULL, &ipg_clk, &aips_tz1_clk);
DEFINE_CLOCK(uart2_ipg_clk, 1, MXC_CCM_CCGR1, MXC_CCM_CCGRx_CG5_OFFSET,
        NULL,  NULL, &ipg_clk, &aips_tz1_clk);
DEFINE_CLOCK(uart3_ipg_clk, 2, MXC_CCM_CCGR1, MXC_CCM_CCGRx_CG7_OFFSET,
        NULL,  NULL, &ipg_clk, &spba_clk);

/* GPT */
DEFINE_CLOCK(gpt_clk, 0, MXC_CCM_CCGR2, MXC_CCM_CCGRx_CG9_OFFSET,
        NULL,  NULL, &ipg_clk, NULL);
DEFINE_CLOCK(gpt_ipg_clk, 0, MXC_CCM_CCGR2, MXC_CCM_CCGRx_CG10_OFFSET,
        NULL,  NULL, &ipg_clk, NULL);

/* FEC */
DEFINE_CLOCK(fec_clk, 0, MXC_CCM_CCGR2, MXC_CCM_CCGRx_CG12_OFFSET,
        NULL,  NULL, &ipg_clk, NULL);

#define _REGISTER_CLOCK(d, n, c) \
       { \
                .dev_id = d, \
                .con_id = n, \
                .clk = &c,   \
       },

static struct clk_lookup lookups[] = {
        _REGISTER_CLOCK("imx-uart.0", NULL, uart1_clk)
        _REGISTER_CLOCK("imx-uart.1", NULL, uart2_clk)
        _REGISTER_CLOCK("imx-uart.2", NULL, uart3_clk)
        _REGISTER_CLOCK(NULL, "gpt", gpt_clk)
        _REGISTER_CLOCK("fec.0", NULL, fec_clk)
        _REGISTER_CLOCK("mxc-ehci.0", "usb", usboh3_clk)
        _REGISTER_CLOCK("mxc-ehci.0", "usb_ahb", ahb_clk)
        _REGISTER_CLOCK("mxc-ehci.1", "usb", usboh3_clk)
        _REGISTER_CLOCK("mxc-ehci.1", "usb_ahb", ahb_clk)
        _REGISTER_CLOCK("fsl-usb2-udc", "usb", usboh3_clk)
        _REGISTER_CLOCK("fsl-usb2-udc", "usb_ahb", ahb_clk)
};

static void clk_tree_init(void)
{
        u32 reg;

        ipg_perclk.set_parent(&ipg_perclk, &lp_apm_clk);

        /*
         * Initialise the IPG PER CLK dividers to 3. IPG_PER_CLK should be at
         * 8MHz, its derived from lp_apm.
         *
         * FIXME: Verify if true for all boards
         */
        reg = __raw_readl(MXC_CCM_CBCDR);
        reg &= ~MXC_CCM_CBCDR_PERCLK_PRED1_MASK;
        reg &= ~MXC_CCM_CBCDR_PERCLK_PRED2_MASK;
        reg &= ~MXC_CCM_CBCDR_PERCLK_PODF_MASK;
        reg |= (2 << MXC_CCM_CBCDR_PERCLK_PRED1_OFFSET);
        __raw_writel(reg, MXC_CCM_CBCDR);
}

int __init mx51_clocks_init(unsigned long ckil, unsigned long osc,
                        unsigned long ckih1, unsigned long ckih2)
{
        int i;

        external_low_reference = ckil;
        external_high_reference = ckih1;
        ckih2_reference = ckih2;
        oscillator_reference = osc;

        for (i = 0; i < ARRAY_SIZE(lookups); i++)
                clkdev_add(&lookups[i]);

        clk_tree_init();

        clk_enable(&cpu_clk);
        clk_enable(&main_bus_clk);

        /* set the usboh3_clk parent to pll2_sw_clk */
        clk_set_parent(&usboh3_clk, &pll2_sw_clk);

        /* System timer */
        mxc_timer_init(&gpt_clk, MX51_IO_ADDRESS(MX51_GPT1_BASE_ADDR),
                MX51_MXC_INT_GPT);
        return 0;
}