Merge remote-tracking branch 'moduleh/module.h-split'

[linux-2.6/next.git] / arch / arm / mach-omap2 / cpuidle34xx.c

/*
 * linux/arch/arm/mach-omap2/cpuidle34xx.c
 *
 * OMAP3 CPU IDLE Routines
 *
 * Copyright (C) 2008 Texas Instruments, Inc.
 * Rajendra Nayak <rnayak@ti.com>
 *
 * Copyright (C) 2007 Texas Instruments, Inc.
 * Karthik Dasu <karthik-dp@ti.com>
 *
 * Copyright (C) 2006 Nokia Corporation
 * Tony Lindgren <tony@atomide.com>
 *
 * Copyright (C) 2005 Texas Instruments, Inc.
 * Richard Woodruff <r-woodruff2@ti.com>
 *
 * Based on pm.c for omap2
 *
 * 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.
 */

#include <linux/sched.h>
#include <linux/cpuidle.h>

#include <plat/prcm.h>
#include <plat/irqs.h>
#include "powerdomain.h"
#include "clockdomain.h"
#include <plat/serial.h>

#include "pm.h"
#include "control.h"

#ifdef CONFIG_CPU_IDLE

/*
 * The latencies/thresholds for various C states have
 * to be configured from the respective board files.
 * These are some default values (which might not provide
 * the best power savings) used on boards which do not
 * pass these details from the board file.
 */
static struct cpuidle_params cpuidle_params_table[] = {
        /* C1 */
        {2 + 2, 5, 1},
        /* C2 */
        {10 + 10, 30, 1},
        /* C3 */
        {50 + 50, 300, 1},
        /* C4 */
        {1500 + 1800, 4000, 1},
        /* C5 */
        {2500 + 7500, 12000, 1},
        /* C6 */
        {3000 + 8500, 15000, 1},
        /* C7 */
        {10000 + 30000, 300000, 1},
};
#define OMAP3_NUM_STATES ARRAY_SIZE(cpuidle_params_table)

/* Mach specific information to be recorded in the C-state driver_data */
struct omap3_idle_statedata {
        u32 mpu_state;
        u32 core_state;
        u8 valid;
};
struct omap3_idle_statedata omap3_idle_data[OMAP3_NUM_STATES];

struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;

static int _cpuidle_allow_idle(struct powerdomain *pwrdm,
                                struct clockdomain *clkdm)
{
        clkdm_allow_idle(clkdm);
        return 0;
}

static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
                                struct clockdomain *clkdm)
{
        clkdm_deny_idle(clkdm);
        return 0;
}

/**
 * omap3_enter_idle - Programs OMAP3 to enter the specified state
 * @dev: cpuidle device
 * @state: The target state to be programmed
 *
 * Called from the CPUidle framework to program the device to the
 * specified target state selected by the governor.
 */
static int omap3_enter_idle(struct cpuidle_device *dev,
                        struct cpuidle_state *state)
{
        struct omap3_idle_statedata *cx = cpuidle_get_statedata(state);
        struct timespec ts_preidle, ts_postidle, ts_idle;
        u32 mpu_state = cx->mpu_state, core_state = cx->core_state;

        /* Used to keep track of the total time in idle */
        getnstimeofday(&ts_preidle);

        local_irq_disable();
        local_fiq_disable();

        pwrdm_set_next_pwrst(mpu_pd, mpu_state);
        pwrdm_set_next_pwrst(core_pd, core_state);

        if (omap_irq_pending() || need_resched())
                goto return_sleep_time;

        /* Deny idle for C1 */
        if (state == &dev->states[0]) {
                pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
                pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
        }

        /* Execute ARM wfi */
        omap_sram_idle();

        /* Re-allow idle for C1 */
        if (state == &dev->states[0]) {
                pwrdm_for_each_clkdm(mpu_pd, _cpuidle_allow_idle);
                pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle);
        }

return_sleep_time:
        getnstimeofday(&ts_postidle);
        ts_idle = timespec_sub(ts_postidle, ts_preidle);

        local_irq_enable();
        local_fiq_enable();

        return ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * USEC_PER_SEC;
}

/**
 * next_valid_state - Find next valid C-state
 * @dev: cpuidle device
 * @state: Currently selected C-state
 *
 * If the current state is valid, it is returned back to the caller.
 * Else, this function searches for a lower c-state which is still
 * valid.
 *
 * A state is valid if the 'valid' field is enabled and
 * if it satisfies the enable_off_mode condition.
 */
static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
                                              struct cpuidle_state *curr)
{
        struct cpuidle_state *next = NULL;
        struct omap3_idle_statedata *cx = cpuidle_get_statedata(curr);
        u32 mpu_deepest_state = PWRDM_POWER_RET;
        u32 core_deepest_state = PWRDM_POWER_RET;

        if (enable_off_mode) {
                mpu_deepest_state = PWRDM_POWER_OFF;
                /*
                 * Erratum i583: valable for ES rev < Es1.2 on 3630.
                 * CORE OFF mode is not supported in a stable form, restrict
                 * instead the CORE state to RET.
                 */
                if (!IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583))
                        core_deepest_state = PWRDM_POWER_OFF;
        }

        /* Check if current state is valid */
        if ((cx->valid) &&
            (cx->mpu_state >= mpu_deepest_state) &&
            (cx->core_state >= core_deepest_state)) {
                return curr;
        } else {
                int idx = OMAP3_NUM_STATES - 1;

                /* Reach the current state starting at highest C-state */
                for (; idx >= 0; idx--) {
                        if (&dev->states[idx] == curr) {
                                next = &dev->states[idx];
                                break;
                        }
                }

                /* Should never hit this condition */
                WARN_ON(next == NULL);

                /*
                 * Drop to next valid state.
                 * Start search from the next (lower) state.
                 */
                idx--;
                for (; idx >= 0; idx--) {
                        cx = cpuidle_get_statedata(&dev->states[idx]);
                        if ((cx->valid) &&
                            (cx->mpu_state >= mpu_deepest_state) &&
                            (cx->core_state >= core_deepest_state)) {
                                next = &dev->states[idx];
                                break;
                        }
                }
                /*
                 * C1 is always valid.
                 * So, no need to check for 'next==NULL' outside this loop.
                 */
        }

        return next;
}

/**
 * omap3_enter_idle_bm - Checks for any bus activity
 * @dev: cpuidle device
 * @state: The target state to be programmed
 *
 * This function checks for any pending activity and then programs
 * the device to the specified or a safer state.
 */
static int omap3_enter_idle_bm(struct cpuidle_device *dev,
                               struct cpuidle_state *state)
{
        struct cpuidle_state *new_state;
        u32 core_next_state, per_next_state = 0, per_saved_state = 0, cam_state;
        struct omap3_idle_statedata *cx;
        int ret;

        if (!omap3_can_sleep()) {
                new_state = dev->safe_state;
                goto select_state;
        }

        /*
         * Prevent idle completely if CAM is active.
         * CAM does not have wakeup capability in OMAP3.
         */
        cam_state = pwrdm_read_pwrst(cam_pd);
        if (cam_state == PWRDM_POWER_ON) {
                new_state = dev->safe_state;
                goto select_state;
        }

        /*
         * FIXME: we currently manage device-specific idle states
         *        for PER and CORE in combination with CPU-specific
         *        idle states.  This is wrong, and device-specific
         *        idle management needs to be separated out into
         *        its own code.
         */

        /*
         * Prevent PER off if CORE is not in retention or off as this
         * would disable PER wakeups completely.
         */
        cx = cpuidle_get_statedata(state);
        core_next_state = cx->core_state;
        per_next_state = per_saved_state = pwrdm_read_next_pwrst(per_pd);
        if ((per_next_state == PWRDM_POWER_OFF) &&
            (core_next_state > PWRDM_POWER_RET))
                per_next_state = PWRDM_POWER_RET;

        /* Are we changing PER target state? */
        if (per_next_state != per_saved_state)
                pwrdm_set_next_pwrst(per_pd, per_next_state);

        new_state = next_valid_state(dev, state);

select_state:
        dev->last_state = new_state;
        ret = omap3_enter_idle(dev, new_state);

        /* Restore original PER state if it was modified */
        if (per_next_state != per_saved_state)
                pwrdm_set_next_pwrst(per_pd, per_saved_state);

        return ret;
}

DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);

void omap3_pm_init_cpuidle(struct cpuidle_params *cpuidle_board_params)
{
        int i;

        if (!cpuidle_board_params)
                return;

        for (i = 0; i < OMAP3_NUM_STATES; i++) {
                cpuidle_params_table[i].valid = cpuidle_board_params[i].valid;
                cpuidle_params_table[i].exit_latency =
                        cpuidle_board_params[i].exit_latency;
                cpuidle_params_table[i].target_residency =
                        cpuidle_board_params[i].target_residency;
        }
        return;
}

struct cpuidle_driver omap3_idle_driver = {
        .name =         "omap3_idle",
        .owner =        THIS_MODULE,
};

/* Helper to fill the C-state common data and register the driver_data */
static inline struct omap3_idle_statedata *_fill_cstate(
                                        struct cpuidle_device *dev,
                                        int idx, const char *descr)
{
        struct omap3_idle_statedata *cx = &omap3_idle_data[idx];
        struct cpuidle_state *state = &dev->states[idx];

        state->exit_latency     = cpuidle_params_table[idx].exit_latency;
        state->target_residency = cpuidle_params_table[idx].target_residency;
        state->flags            = CPUIDLE_FLAG_TIME_VALID;
        state->enter            = omap3_enter_idle_bm;
        cx->valid               = cpuidle_params_table[idx].valid;
        sprintf(state->name, "C%d", idx + 1);
        strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
        cpuidle_set_statedata(state, cx);

        return cx;
}

/**
 * omap3_idle_init - Init routine for OMAP3 idle
 *
 * Registers the OMAP3 specific cpuidle driver to the cpuidle
 * framework with the valid set of states.
 */
int __init omap3_idle_init(void)
{
        struct cpuidle_device *dev;
        struct omap3_idle_statedata *cx;

        mpu_pd = pwrdm_lookup("mpu_pwrdm");
        core_pd = pwrdm_lookup("core_pwrdm");
        per_pd = pwrdm_lookup("per_pwrdm");
        cam_pd = pwrdm_lookup("cam_pwrdm");

        cpuidle_register_driver(&omap3_idle_driver);
        dev = &per_cpu(omap3_idle_dev, smp_processor_id());

        /* C1 . MPU WFI + Core active */
        cx = _fill_cstate(dev, 0, "MPU ON + CORE ON");
        (&dev->states[0])->enter = omap3_enter_idle;
        dev->safe_state = &dev->states[0];
        cx->valid = 1;  /* C1 is always valid */
        cx->mpu_state = PWRDM_POWER_ON;
        cx->core_state = PWRDM_POWER_ON;

        /* C2 . MPU WFI + Core inactive */
        cx = _fill_cstate(dev, 1, "MPU ON + CORE ON");
        cx->mpu_state = PWRDM_POWER_ON;
        cx->core_state = PWRDM_POWER_ON;

        /* C3 . MPU CSWR + Core inactive */
        cx = _fill_cstate(dev, 2, "MPU RET + CORE ON");
        cx->mpu_state = PWRDM_POWER_RET;
        cx->core_state = PWRDM_POWER_ON;

        /* C4 . MPU OFF + Core inactive */
        cx = _fill_cstate(dev, 3, "MPU OFF + CORE ON");
        cx->mpu_state = PWRDM_POWER_OFF;
        cx->core_state = PWRDM_POWER_ON;

        /* C5 . MPU RET + Core RET */
        cx = _fill_cstate(dev, 4, "MPU RET + CORE RET");
        cx->mpu_state = PWRDM_POWER_RET;
        cx->core_state = PWRDM_POWER_RET;

        /* C6 . MPU OFF + Core RET */
        cx = _fill_cstate(dev, 5, "MPU OFF + CORE RET");
        cx->mpu_state = PWRDM_POWER_OFF;
        cx->core_state = PWRDM_POWER_RET;

        /* C7 . MPU OFF + Core OFF */
        cx = _fill_cstate(dev, 6, "MPU OFF + CORE OFF");
        /*
         * Erratum i583: implementation for ES rev < Es1.2 on 3630. We cannot
         * enable OFF mode in a stable form for previous revisions.
         * We disable C7 state as a result.
         */
        if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583)) {
                cx->valid = 0;
                pr_warn("%s: core off state C7 disabled due to i583\n",
                        __func__);
        }
        cx->mpu_state = PWRDM_POWER_OFF;
        cx->core_state = PWRDM_POWER_OFF;

        dev->state_count = OMAP3_NUM_STATES;
        if (cpuidle_register_device(dev)) {
                printk(KERN_ERR "%s: CPUidle register device failed\n",
                       __func__);
                return -EIO;
        }

        return 0;
}
#else
int __init omap3_idle_init(void)
{
        return 0;
}
#endif /* CONFIG_CPU_IDLE */