OMAP3 clock: recalculate DPLL subtree after bypass entry/exit

[linux-2.6-omap-h63xx.git] / arch / arm / mach-omap2 / clock34xx.c

/*
 * OMAP3-specific clock framework functions
 *
 * Copyright (C) 2007-2008 Texas Instruments, Inc.
 * Copyright (C) 2007-2008 Nokia Corporation
 *
 * Written by Paul Walmsley
 * Testing and integration fixes by Jouni Högander
 *
 * Parts of this code are based on code written by
 * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#undef DEBUG

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/limits.h>

#include <mach/clock.h>
#include <mach/sram.h>
#include <asm/div64.h>
#include <asm/bitops.h>

#include <mach/sdrc.h>
#include "clock.h"
#include "clock34xx.h"
#include "prm.h"
#include "prm-regbits-34xx.h"
#include "cm.h"
#include "cm-regbits-34xx.h"

/* CM_AUTOIDLE_PLL*.AUTO_* bit values */
#define DPLL_AUTOIDLE_DISABLE                   0x0
#define DPLL_AUTOIDLE_LOW_POWER_STOP            0x1

#define MAX_DPLL_WAIT_TRIES             1000000

/**
 * omap3_dpll_recalc - recalculate DPLL rate
 * @clk: DPLL struct clk
 *
 * Recalculate and propagate the DPLL rate.
 */
static void omap3_dpll_recalc(struct clk *clk)
{
        clk->rate = omap2_get_dpll_rate(clk);

        propagate_rate(clk);
}

/* _omap3_dpll_write_clken - write clken_bits arg to a DPLL's enable bits */
static void _omap3_dpll_write_clken(struct clk *clk, u8 clken_bits)
{
        const struct dpll_data *dd;
        u32 v;

        dd = clk->dpll_data;

        v = __raw_readl(dd->control_reg);
        v &= ~dd->enable_mask;
        v |= clken_bits << __ffs(dd->enable_mask);
        __raw_writel(v, dd->control_reg);
}

/* _omap3_wait_dpll_status: wait for a DPLL to enter a specific state */
static int _omap3_wait_dpll_status(struct clk *clk, u8 state)
{
        const struct dpll_data *dd;
        int i = 0;
        int ret = -EINVAL;

        dd = clk->dpll_data;

        state <<= __ffs(dd->idlest_mask);

        while (((__raw_readl(dd->idlest_reg) & dd->idlest_mask) != state) &&
               i < MAX_DPLL_WAIT_TRIES) {
                i++;
                udelay(1);
        }

        if (i == MAX_DPLL_WAIT_TRIES) {
                printk(KERN_ERR "clock: %s failed transition to '%s'\n",
                       clk->name, (state) ? "locked" : "bypassed");
        } else {
                pr_debug("clock: %s transition to '%s' in %d loops\n",
                         clk->name, (state) ? "locked" : "bypassed", i);

                ret = 0;
        }

        return ret;
}

/* From 3430 TRM ES2 4.7.6.2 */
static u16 _omap3_dpll_compute_freqsel(struct clk *clk, u8 n)
{
        unsigned long fint;
        u16 f = 0;

        fint = clk->parent->rate / (n + 1);

        pr_debug("clock: fint is %lu\n", fint);

        if (fint >= 750000 && fint <= 1000000)
                f = 0x3;
        else if (fint > 1000000 && fint <= 1250000)
                f = 0x4;
        else if (fint > 1250000 && fint <= 1500000)
                f = 0x5;
        else if (fint > 1500000 && fint <= 1750000)
                f = 0x6;
        else if (fint > 1750000 && fint <= 2100000)
                f = 0x7;
        else if (fint > 7500000 && fint <= 10000000)
                f = 0xB;
        else if (fint > 10000000 && fint <= 12500000)
                f = 0xC;
        else if (fint > 12500000 && fint <= 15000000)
                f = 0xD;
        else if (fint > 15000000 && fint <= 17500000)
                f = 0xE;
        else if (fint > 17500000 && fint <= 21000000)
                f = 0xF;
        else
                pr_debug("clock: unknown freqsel setting for %d\n", n);

        return f;
}

/* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */

/*
 * _omap3_noncore_dpll_lock - instruct a DPLL to lock and wait for readiness
 * @clk: pointer to a DPLL struct clk
 *
 * Instructs a non-CORE DPLL to lock.  Waits for the DPLL to report
 * readiness before returning.  Will save and restore the DPLL's
 * autoidle state across the enable, per the CDP code.  If the DPLL
 * locked successfully, return 0; if the DPLL did not lock in the time
 * allotted, or DPLL3 was passed in, return -EINVAL.
 */
static int _omap3_noncore_dpll_lock(struct clk *clk)
{
        u8 ai;
        int r;

        if (clk == &dpll3_ck)
                return -EINVAL;

        pr_debug("clock: locking DPLL %s\n", clk->name);

        ai = omap3_dpll_autoidle_read(clk);

        _omap3_dpll_write_clken(clk, DPLL_LOCKED);

        if (ai) {
                /*
                 * If no downstream clocks are enabled, CM_IDLEST bit
                 * may never become active, so don't wait for DPLL to lock.
                 */
                r = 0;
                omap3_dpll_allow_idle(clk);
        } else {
                r = _omap3_wait_dpll_status(clk, 1);
                omap3_dpll_deny_idle(clk);
        };

        return r;
}

/*
 * _omap3_noncore_dpll_bypass - instruct a DPLL to bypass and wait for readiness
 * @clk: pointer to a DPLL struct clk
 *
 * Instructs a non-CORE DPLL to enter low-power bypass mode.  In
 * bypass mode, the DPLL's rate is set equal to its parent clock's
 * rate.  Waits for the DPLL to report readiness before returning.
 * Will save and restore the DPLL's autoidle state across the enable,
 * per the CDP code.  If the DPLL entered bypass mode successfully,
 * return 0; if the DPLL did not enter bypass in the time allotted, or
 * DPLL3 was passed in, or the DPLL does not support low-power bypass,
 * return -EINVAL.
 */
static int _omap3_noncore_dpll_bypass(struct clk *clk)
{
        int r;
        u8 ai;

        if (clk == &dpll3_ck)
                return -EINVAL;

        if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS)))
                return -EINVAL;

        pr_debug("clock: configuring DPLL %s for low-power bypass\n",
                 clk->name);

        ai = omap3_dpll_autoidle_read(clk);

        _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_BYPASS);

        r = _omap3_wait_dpll_status(clk, 0);

        if (ai)
                omap3_dpll_allow_idle(clk);
        else
                omap3_dpll_deny_idle(clk);

        return r;
}

/*
 * _omap3_noncore_dpll_stop - instruct a DPLL to stop
 * @clk: pointer to a DPLL struct clk
 *
 * Instructs a non-CORE DPLL to enter low-power stop. Will save and
 * restore the DPLL's autoidle state across the stop, per the CDP
 * code.  If DPLL3 was passed in, or the DPLL does not support
 * low-power stop, return -EINVAL; otherwise, return 0.
 */
static int _omap3_noncore_dpll_stop(struct clk *clk)
{
        u8 ai;

        if (clk == &dpll3_ck)
                return -EINVAL;

        if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_STOP)))
                return -EINVAL;

        pr_debug("clock: stopping DPLL %s\n", clk->name);

        ai = omap3_dpll_autoidle_read(clk);

        _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_STOP);

        if (ai)
                omap3_dpll_allow_idle(clk);
        else
                omap3_dpll_deny_idle(clk);

        return 0;
}

/**
 * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
 * @clk: pointer to a DPLL struct clk
 *
 * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
 * The choice of modes depends on the DPLL's programmed rate: if it is
 * the same as the DPLL's parent clock, it will enter bypass;
 * otherwise, it will enter lock.  This code will wait for the DPLL to
 * indicate readiness before returning, unless the DPLL takes too long
 * to enter the target state.  Intended to be used as the struct clk's
 * enable function.  If DPLL3 was passed in, or the DPLL does not
 * support low-power stop, or if the DPLL took too long to enter
 * bypass or lock, return -EINVAL; otherwise, return 0.
 */
static int omap3_noncore_dpll_enable(struct clk *clk)
{
        int r;
        long rate;
        struct dpll_data *dd;

        if (clk == &dpll3_ck)
                return -EINVAL;

        dd = clk->dpll_data;
        if (!dd)
                return -EINVAL;

        rate = omap2_get_dpll_rate(clk);

        if (dd->bypass_clk->rate == rate)
                r = _omap3_noncore_dpll_bypass(clk);
        else
                r = _omap3_noncore_dpll_lock(clk);

        if (!r)
                clk->rate = rate;

        return r;
}

/**
 * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
 * @clk: pointer to a DPLL struct clk
 *
 * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
 * The choice of modes depends on the DPLL's programmed rate: if it is
 * the same as the DPLL's parent clock, it will enter bypass;
 * otherwise, it will enter lock.  This code will wait for the DPLL to
 * indicate readiness before returning, unless the DPLL takes too long
 * to enter the target state.  Intended to be used as the struct clk's
 * enable function.  If DPLL3 was passed in, or the DPLL does not
 * support low-power stop, or if the DPLL took too long to enter
 * bypass or lock, return -EINVAL; otherwise, return 0.
 */
static void omap3_noncore_dpll_disable(struct clk *clk)
{
        if (clk == &dpll3_ck)
                return;

        _omap3_noncore_dpll_stop(clk);
}


/* Non-CORE DPLL rate set code */

/*
 * omap3_noncore_dpll_program - set non-core DPLL M,N values directly
 * @clk: struct clk * of DPLL to set
 * @m: DPLL multiplier to set
 * @n: DPLL divider to set
 * @freqsel: FREQSEL value to set
 *
 * Program the DPLL with the supplied M, N values, and wait for the DPLL to
 * lock..  Returns -EINVAL upon error, or 0 upon success.
 */
static int omap3_noncore_dpll_program(struct clk *clk, u16 m, u8 n, u16 freqsel)
{
        struct dpll_data *dd;
        u32 v;

        if (!clk)
                return -EINVAL;

        dd = clk->dpll_data;
        if (!dd)
                return -EINVAL;

        /*
         * According to the 12-5 CDP code from TI, "Limitation 2.5"
         * on 3430ES1 prevents us from changing DPLL multipliers or dividers
         * on DPLL4.
         */
        if (system_rev == OMAP3430_REV_ES1_0 &&
            !strcmp("dpll4_ck", clk->name)) {
                printk(KERN_ERR "clock: DPLL4 cannot change rate due to "
                       "silicon 'Limitation 2.5' on 3430ES1.\n");
                return -EINVAL;
        }

        /* 3430 ES2 TRM: 4.7.6.9 DPLL Programming Sequence */
        _omap3_noncore_dpll_bypass(clk);

        /* Set jitter correction */
        v = __raw_readl(dd->control_reg);
        v &= ~dd->freqsel_mask;
        v |= freqsel << __ffs(dd->freqsel_mask);
        __raw_writel(v, dd->control_reg);

        /* Set DPLL multiplier, divider */
        v = __raw_readl(dd->mult_div1_reg);
        v &= ~(dd->mult_mask | dd->div1_mask);
        v |= m << __ffs(dd->mult_mask);
        v |= (n - 1) << __ffs(dd->div1_mask);
        __raw_writel(v, dd->mult_div1_reg);

        /* We let the clock framework set the other output dividers later */

        /* REVISIT: Set ramp-up delay? */

        _omap3_noncore_dpll_lock(clk);

        return 0;
}

/**
 * omap3_noncore_dpll_set_rate - set non-core DPLL rate
 * @clk: struct clk * of DPLL to set
 * @rate: rounded target rate
 *
 * Set the DPLL CLKOUT to the target rate.  If the DPLL can enter
 * low-power bypass, and the target rate is the bypass source clock
 * rate, then configure the DPLL for bypass.  Otherwise, round the
 * target rate if it hasn't been done already, then program and lock
 * the DPLL.  Returns -EINVAL upon error, or 0 upon success.
 */
static int omap3_noncore_dpll_set_rate(struct clk *clk, unsigned long rate)
{
        u16 freqsel;
        struct dpll_data *dd;
        int ret;

        if (!clk || !rate)
                return -EINVAL;

        dd = clk->dpll_data;
        if (!dd)
                return -EINVAL;

        if (rate == omap2_get_dpll_rate(clk))
                return 0;

        if (dd->bypass_clk->rate == rate &&
            (clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS))) {

                pr_debug("clock: %s: set rate: entering bypass.\n", clk->name);

                ret = _omap3_noncore_dpll_bypass(clk);
                if (!ret)
                        clk->rate = rate;

        } else {

                if (dd->last_rounded_rate != rate)
                        omap2_dpll_round_rate(clk, rate);

                if (dd->last_rounded_rate == 0)
                        return -EINVAL;

                freqsel = _omap3_dpll_compute_freqsel(clk, dd->last_rounded_n);
                if (!freqsel)
                        WARN_ON(1);

                pr_debug("clock: %s: set rate: locking rate to %lu.\n",
                         clk->name, rate);

                ret = omap3_noncore_dpll_program(clk, dd->last_rounded_m,
                                                 dd->last_rounded_n, freqsel);

        }

        omap3_dpll_recalc(clk);

        return 0;
}


/*
 * CORE DPLL (DPLL3) rate programming functions
 *
 * These call into SRAM code to do the actual CM writes, since the SDRAM
 * is clocked from DPLL3.
 */

/**
 * omap3_core_dpll_m2_set_rate - set CORE DPLL M2 divider
 * @clk: struct clk * of DPLL to set
 * @rate: rounded target rate
 *
 * Program the DPLL M2 divider with the rounded target rate.  Returns
 * -EINVAL upon error, or 0 upon success.
 */
static int omap3_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate)
{
        u32 new_div = 0;
        unsigned long validrate, sdrcrate;
        struct omap_sdrc_params *sp;

        if (!clk || !rate)
                return -EINVAL;

        if (clk != &dpll3_m2_ck)
                return -EINVAL;

        if (rate == clk->rate)
                return 0;

        validrate = omap2_clksel_round_rate_div(clk, rate, &new_div);
        if (validrate != rate)
                return -EINVAL;

        sdrcrate = sdrc_ick.rate;
        if (rate > clk->rate)
                sdrcrate <<= ((rate / clk->rate) - 1);
        else
                sdrcrate >>= ((clk->rate / rate) - 1);

        sp = omap2_sdrc_get_params(sdrcrate);
        if (!sp)
                return -EINVAL;

        pr_info("clock: changing CORE DPLL rate from %lu to %lu\n", clk->rate,
                validrate);
        pr_info("clock: SDRC timing params used: %08x %08x %08x\n",
                sp->rfr_ctrl, sp->actim_ctrla, sp->actim_ctrlb);

        /* REVISIT: SRAM code doesn't support other M2 divisors yet */
        WARN_ON(new_div != 1 && new_div != 2);

        /* REVISIT: Add SDRC_MR changing to this code also */
        local_irq_disable();
        omap3_configure_core_dpll(sp->rfr_ctrl, sp->actim_ctrla,
                                  sp->actim_ctrlb, new_div);
        local_irq_enable();

        omap2_clksel_recalc(clk);

        return 0;
}


/* DPLL autoidle read/set code */


/**
 * omap3_dpll_autoidle_read - read a DPLL's autoidle bits
 * @clk: struct clk * of the DPLL to read
 *
 * Return the DPLL's autoidle bits, shifted down to bit 0.  Returns
 * -EINVAL if passed a null pointer or if the struct clk does not
 * appear to refer to a DPLL.
 */
static u32 omap3_dpll_autoidle_read(struct clk *clk)
{
        const struct dpll_data *dd;
        u32 v;

        if (!clk || !clk->dpll_data)
                return -EINVAL;

        dd = clk->dpll_data;

        v = __raw_readl(dd->autoidle_reg);
        v &= dd->autoidle_mask;
        v >>= __ffs(dd->autoidle_mask);

        return v;
}

/**
 * omap3_dpll_allow_idle - enable DPLL autoidle bits
 * @clk: struct clk * of the DPLL to operate on
 *
 * Enable DPLL automatic idle control.  This automatic idle mode
 * switching takes effect only when the DPLL is locked, at least on
 * OMAP3430.  The DPLL will enter low-power stop when its downstream
 * clocks are gated.  No return value.
 */
static void omap3_dpll_allow_idle(struct clk *clk)
{
        const struct dpll_data *dd;
        u32 v;

        if (!clk || !clk->dpll_data)
                return;

        dd = clk->dpll_data;

        /*
         * REVISIT: CORE DPLL can optionally enter low-power bypass
         * by writing 0x5 instead of 0x1.  Add some mechanism to
         * optionally enter this mode.
         */
        v = __raw_readl(dd->autoidle_reg);
        v &= ~dd->autoidle_mask;
        v |= DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask);
        __raw_writel(v, dd->autoidle_reg);
}

/**
 * omap3_dpll_deny_idle - prevent DPLL from automatically idling
 * @clk: struct clk * of the DPLL to operate on
 *
 * Disable DPLL automatic idle control.  No return value.
 */
static void omap3_dpll_deny_idle(struct clk *clk)
{
        const struct dpll_data *dd;
        u32 v;

        if (!clk || !clk->dpll_data)
                return;

        dd = clk->dpll_data;

        v = __raw_readl(dd->autoidle_reg);
        v &= ~dd->autoidle_mask;
        v |= DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask);
        __raw_writel(v, dd->autoidle_reg);
}

/* Clock control for DPLL outputs */

/**
 * omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate
 * @clk: DPLL output struct clk
 *
 * Using parent clock DPLL data, look up DPLL state.  If locked, set our
 * rate to the dpll_clk * 2; otherwise, just use dpll_clk.
 */
static void omap3_clkoutx2_recalc(struct clk *clk)
{
        const struct dpll_data *dd;
        u32 v;
        struct clk *pclk;

        /* Walk up the parents of clk, looking for a DPLL */
        pclk = clk->parent;
        while (pclk && !pclk->dpll_data)
                pclk = pclk->parent;

        /* clk does not have a DPLL as a parent? */
        WARN_ON(!pclk);

        dd = pclk->dpll_data;

        WARN_ON(!dd->idlest_reg || !dd->idlest_mask);

        v = __raw_readl(dd->idlest_reg) & dd->idlest_mask;
        if (!v)
                clk->rate = clk->parent->rate;
        else
                clk->rate = clk->parent->rate * 2;

        if (clk->flags & RATE_PROPAGATES)
                propagate_rate(clk);
}

/* Common clock code */

/*
 * As it is structured now, this will prevent an OMAP2/3 multiboot
 * kernel from compiling.  This will need further attention.
 */
#if defined(CONFIG_ARCH_OMAP3)

static struct clk_functions omap2_clk_functions = {
        .clk_enable             = omap2_clk_enable,
        .clk_disable            = omap2_clk_disable,
        .clk_round_rate         = omap2_clk_round_rate,
        .clk_set_rate           = omap2_clk_set_rate,
        .clk_set_parent         = omap2_clk_set_parent,
        .clk_disable_unused     = omap2_clk_disable_unused,
};

/*
 * Set clocks for bypass mode for reboot to work.
 */
void omap2_clk_prepare_for_reboot(void)
{
        /* REVISIT: Not ready for 343x */
#if 0
        u32 rate;

        if (vclk == NULL || sclk == NULL)
                return;

        rate = clk_get_rate(sclk);
        clk_set_rate(vclk, rate);
#endif
}

/* REVISIT: Move this init stuff out into clock.c */

/*
 * Switch the MPU rate if specified on cmdline.
 * We cannot do this early until cmdline is parsed.
 */
static int __init omap2_clk_arch_init(void)
{
        if (!mpurate)
                return -EINVAL;

        /* REVISIT: not yet ready for 343x */
#if 0
        if (omap2_select_table_rate(&virt_prcm_set, mpurate))
                printk(KERN_ERR "Could not find matching MPU rate\n");
#endif

        recalculate_root_clocks();

        printk(KERN_INFO "Switched to new clocking rate (Crystal/DPLL3/MPU): "
               "%ld.%01ld/%ld/%ld MHz\n",
               (osc_sys_ck.rate / 1000000), (osc_sys_ck.rate / 100000) % 10,
               (core_ck.rate / 1000000), (dpll1_fck.rate / 1000000)) ;

        return 0;
}
arch_initcall(omap2_clk_arch_init);

int __init omap2_clk_init(void)
{
        /* struct prcm_config *prcm; */
        struct clk **clkp;
        /* u32 clkrate; */
        u32 cpu_clkflg;

        /* REVISIT: Ultimately this will be used for multiboot */
#if 0
        if (cpu_is_omap242x()) {
                cpu_mask = RATE_IN_242X;
                cpu_clkflg = CLOCK_IN_OMAP242X;
                clkp = onchip_24xx_clks;
        } else if (cpu_is_omap2430()) {
                cpu_mask = RATE_IN_243X;
                cpu_clkflg = CLOCK_IN_OMAP243X;
                clkp = onchip_24xx_clks;
        }
#endif
        if (cpu_is_omap34xx()) {
                cpu_mask = RATE_IN_343X;
                cpu_clkflg = CLOCK_IN_OMAP343X;
                clkp = onchip_34xx_clks;

                /*
                 * Update this if there are further clock changes between ES2
                 * and production parts
                 */
                if (system_rev == OMAP3430_REV_ES1_0) {
                        /* No 3430ES1-only rates exist, so no RATE_IN_3430ES1 */
                        cpu_clkflg |= CLOCK_IN_OMAP3430ES1;
                } else {
                        cpu_mask |= RATE_IN_3430ES2;
                        cpu_clkflg |= CLOCK_IN_OMAP3430ES2;
                }
        }

        clk_init(&omap2_clk_functions);

        for (clkp = onchip_34xx_clks;
             clkp < onchip_34xx_clks + ARRAY_SIZE(onchip_34xx_clks);
             clkp++) {
                if ((*clkp)->flags & cpu_clkflg) {
                        clk_register(*clkp);
                        omap2_init_clk_clkdm(*clkp);
                }
        }

        /* REVISIT: Not yet ready for OMAP3 */
#if 0
        /* Check the MPU rate set by bootloader */
        clkrate = omap2_get_dpll_rate_24xx(&dpll_ck);
        for (prcm = rate_table; prcm->mpu_speed; prcm++) {
                if (!(prcm->flags & cpu_mask))
                        continue;
                if (prcm->xtal_speed != sys_ck.rate)
                        continue;
                if (prcm->dpll_speed <= clkrate)
                         break;
        }
        curr_prcm_set = prcm;
#endif

        recalculate_root_clocks();

        printk(KERN_INFO "Clocking rate (Crystal/DPLL/ARM core): "
               "%ld.%01ld/%ld/%ld MHz\n",
               (osc_sys_ck.rate / 1000000), (osc_sys_ck.rate / 100000) % 10,
               (core_ck.rate / 1000000), (arm_fck.rate / 1000000));

        /*
         * Only enable those clocks we will need, let the drivers
         * enable other clocks as necessary
         */
        clk_enable_init_clocks();

        /* Avoid sleeping during omap2_clk_prepare_for_reboot() */
        /* REVISIT: not yet ready for 343x */
#if 0
        vclk = clk_get(NULL, "virt_prcm_set");
        sclk = clk_get(NULL, "sys_ck");
#endif
        return 0;
}

#endif