/*
 * 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

#define OMAP3_MAX_STATES 7
#define OMAP3_STATE_C1 0 /* C1 - MPU WFI + Core active */
#define OMAP3_STATE_C2 1 /* C2 - MPU WFI + Core inactive */
#define OMAP3_STATE_C3 2 /* C3 - MPU CSWR + Core inactive */
#define OMAP3_STATE_C4 3 /* C4 - MPU OFF + Core iactive */
#define OMAP3_STATE_C5 4 /* C5 - MPU RET + Core RET */
#define OMAP3_STATE_C6 5 /* C6 - MPU OFF + Core RET */
#define OMAP3_STATE_C7 6 /* C7 - MPU OFF + Core OFF */

#define OMAP3_STATE_MAX OMAP3_STATE_C7

#define CPUIDLE_FLAG_CHECK_BM   0x10000 /* use omap3_enter_idle_bm() */

struct omap3_processor_cx {
        u8 valid;
        u8 type;
        u32 sleep_latency;
        u32 wakeup_latency;
        u32 mpu_state;
        u32 core_state;
        u32 threshold;
        u32 flags;
};

struct omap3_processor_cx omap3_power_states[OMAP3_MAX_STATES];
struct omap3_processor_cx current_cx_state;
struct powerdomain *mpu_pd, *core_pd, *per_pd;
struct powerdomain *cam_pd;

/*
 * 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 */
        {1, 2, 2, 5},
        /* C2 */
        {1, 10, 10, 30},
        /* C3 */
        {1, 50, 50, 300},
        /* C4 */
        {1, 1500, 1800, 4000},
        /* C5 */
        {1, 2500, 7500, 12000},
        /* C6 */
        {1, 3000, 8500, 15000},
        /* C7 */
        {1, 10000, 30000, 300000},
};

static int omap3_idle_bm_check(void)
{
        if (!omap3_can_sleep())
                return 1;
        return 0;
}

static int _cpuidle_allow_idle(struct powerdomain *pwrdm,
                                struct clockdomain *clkdm)
{
        omap2_clkdm_allow_idle(clkdm);
        return 0;
}

static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
                                struct clockdomain *clkdm)
{
        omap2_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_processor_cx *cx = cpuidle_get_statedata(state);
        struct timespec ts_preidle, ts_postidle, ts_idle;
        u32 mpu_state = cx->mpu_state, core_state = cx->core_state;

        current_cx_state = *cx;

        /* 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;

        if (cx->type == OMAP3_STATE_C1) {
                pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
                pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
        }

        /* Execute ARM wfi */
        omap_sram_idle();

        if (cx->type == OMAP3_STATE_C1) {
                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 (as defined in omap3_power_states[]).
 */
static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
                                                struct cpuidle_state *curr)
{
        struct cpuidle_state *next = NULL;
        struct omap3_processor_cx *cx;

        cx = (struct omap3_processor_cx *)cpuidle_get_statedata(curr);

        /* Check if current state is valid */
        if (cx->valid) {
                return curr;
        } else {
                u8 idx = OMAP3_STATE_MAX;

                /*
                 * Reach the current state starting at highest C-state
                 */
                for (; idx >= OMAP3_STATE_C1; 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 >= OMAP3_STATE_C1; idx--) {
                        struct omap3_processor_cx *cx;

                        cx = cpuidle_get_statedata(&dev->states[idx]);
                        if (cx->valid) {
                                next = &dev->states[idx];
                                break;
                        }
                }
                /*
                 * C1 and C2 are 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
 *
 * Used for C states with CPUIDLE_FLAG_CHECK_BM flag set. 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 = next_valid_state(dev, state);
        u32 core_next_state, per_next_state = 0, per_saved_state = 0;
        u32 cam_state;
        struct omap3_processor_cx *cx;
        int ret;

        if ((state->flags & CPUIDLE_FLAG_CHECK_BM) && omap3_idle_bm_check()) {
                BUG_ON(!dev->safe_state);
                new_state = dev->safe_state;
                goto select_state;
        }

        cx = cpuidle_get_statedata(state);
        core_next_state = cx->core_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 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;
        }

        /*
         * Prevent PER off if CORE is not in retention or off as this
         * would disable PER wakeups completely.
         */
        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);

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);

/**
 * omap3_cpuidle_update_states() - Update the cpuidle states
 * @mpu_deepest_state:  Enable states upto and including this for mpu domain
 * @core_deepest_state: Enable states upto and including this for core domain
 *
 * This goes through the list of states available and enables and disables the
 * validity of C states based on deepest state that can be achieved for the
 * variable domain
 */
void omap3_cpuidle_update_states(u32 mpu_deepest_state, u32 core_deepest_state)
{
        int i;

        for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
                struct omap3_processor_cx *cx = &omap3_power_states[i];

                if ((cx->mpu_state >= mpu_deepest_state) &&
                    (cx->core_state >= core_deepest_state)) {
                        cx->valid = 1;
                } else {
                        cx->valid = 0;
                }
        }
}

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

        if (!cpuidle_board_params)
                return;

        for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
                cpuidle_params_table[i].valid =
                        cpuidle_board_params[i].valid;
                cpuidle_params_table[i].sleep_latency =
                        cpuidle_board_params[i].sleep_latency;
                cpuidle_params_table[i].wake_latency =
                        cpuidle_board_params[i].wake_latency;
                cpuidle_params_table[i].threshold =
                        cpuidle_board_params[i].threshold;
        }
        return;
}

/* omap3_init_power_states - Initialises the OMAP3 specific C states.
 *
 * Below is the desciption of each C state.
 *      C1 . MPU WFI + Core active
 *      C2 . MPU WFI + Core inactive
 *      C3 . MPU CSWR + Core inactive
 *      C4 . MPU OFF + Core inactive
 *      C5 . MPU CSWR + Core CSWR
 *      C6 . MPU OFF + Core CSWR
 *      C7 . MPU OFF + Core OFF
 */
void omap_init_power_states(void)
{
        /* C1 . MPU WFI + Core active */
        omap3_power_states[OMAP3_STATE_C1].valid =
                        cpuidle_params_table[OMAP3_STATE_C1].valid;
        omap3_power_states[OMAP3_STATE_C1].type = OMAP3_STATE_C1;
        omap3_power_states[OMAP3_STATE_C1].sleep_latency =
                        cpuidle_params_table[OMAP3_STATE_C1].sleep_latency;
        omap3_power_states[OMAP3_STATE_C1].wakeup_latency =
                        cpuidle_params_table[OMAP3_STATE_C1].wake_latency;
        omap3_power_states[OMAP3_STATE_C1].threshold =
                        cpuidle_params_table[OMAP3_STATE_C1].threshold;
        omap3_power_states[OMAP3_STATE_C1].mpu_state = PWRDM_POWER_ON;
        omap3_power_states[OMAP3_STATE_C1].core_state = PWRDM_POWER_ON;
        omap3_power_states[OMAP3_STATE_C1].flags = CPUIDLE_FLAG_TIME_VALID;

        /* C2 . MPU WFI + Core inactive */
        omap3_power_states[OMAP3_STATE_C2].valid =
                        cpuidle_params_table[OMAP3_STATE_C2].valid;
        omap3_power_states[OMAP3_STATE_C2].type = OMAP3_STATE_C2;
        omap3_power_states[OMAP3_STATE_C2].sleep_latency =
                        cpuidle_params_table[OMAP3_STATE_C2].sleep_latency;
        omap3_power_states[OMAP3_STATE_C2].wakeup_latency =
                        cpuidle_params_table[OMAP3_STATE_C2].wake_latency;
        omap3_power_states[OMAP3_STATE_C2].threshold =
                        cpuidle_params_table[OMAP3_STATE_C2].threshold;
        omap3_power_states[OMAP3_STATE_C2].mpu_state = PWRDM_POWER_ON;
        omap3_power_states[OMAP3_STATE_C2].core_state = PWRDM_POWER_ON;
        omap3_power_states[OMAP3_STATE_C2].flags = CPUIDLE_FLAG_TIME_VALID |
                                CPUIDLE_FLAG_CHECK_BM;

        /* C3 . MPU CSWR + Core inactive */
        omap3_power_states[OMAP3_STATE_C3].valid =
                        cpuidle_params_table[OMAP3_STATE_C3].valid;
        omap3_power_states[OMAP3_STATE_C3].type = OMAP3_STATE_C3;
        omap3_power_states[OMAP3_STATE_C3].sleep_latency =
                        cpuidle_params_table[OMAP3_STATE_C3].sleep_latency;
        omap3_power_states[OMAP3_STATE_C3].wakeup_latency =
                        cpuidle_params_table[OMAP3_STATE_C3].wake_latency;
        omap3_power_states[OMAP3_STATE_C3].threshold =
                        cpuidle_params_table[OMAP3_STATE_C3].threshold;
        omap3_power_states[OMAP3_STATE_C3].mpu_state = PWRDM_POWER_RET;
        omap3_power_states[OMAP3_STATE_C3].core_state = PWRDM_POWER_ON;
        omap3_power_states[OMAP3_STATE_C3].flags = CPUIDLE_FLAG_TIME_VALID |
                                CPUIDLE_FLAG_CHECK_BM;

        /* C4 . MPU OFF + Core inactive */
        omap3_power_states[OMAP3_STATE_C4].valid =
                        cpuidle_params_table[OMAP3_STATE_C4].valid;
        omap3_power_states[OMAP3_STATE_C4].type = OMAP3_STATE_C4;
        omap3_power_states[OMAP3_STATE_C4].sleep_latency =
                        cpuidle_params_table[OMAP3_STATE_C4].sleep_latency;
        omap3_power_states[OMAP3_STATE_C4].wakeup_latency =
                        cpuidle_params_table[OMAP3_STATE_C4].wake_latency;
        omap3_power_states[OMAP3_STATE_C4].threshold =
                        cpuidle_params_table[OMAP3_STATE_C4].threshold;
        omap3_power_states[OMAP3_STATE_C4].mpu_state = PWRDM_POWER_OFF;
        omap3_power_states[OMAP3_STATE_C4].core_state = PWRDM_POWER_ON;
        omap3_power_states[OMAP3_STATE_C4].flags = CPUIDLE_FLAG_TIME_VALID |
                                CPUIDLE_FLAG_CHECK_BM;

        /* C5 . MPU CSWR + Core CSWR*/
        omap3_power_states[OMAP3_STATE_C5].valid =
                        cpuidle_params_table[OMAP3_STATE_C5].valid;
        omap3_power_states[OMAP3_STATE_C5].type = OMAP3_STATE_C5;
        omap3_power_states[OMAP3_STATE_C5].sleep_latency =
                        cpuidle_params_table[OMAP3_STATE_C5].sleep_latency;
        omap3_power_states[OMAP3_STATE_C5].wakeup_latency =
                        cpuidle_params_table[OMAP3_STATE_C5].wake_latency;
        omap3_power_states[OMAP3_STATE_C5].threshold =
                        cpuidle_params_table[OMAP3_STATE_C5].threshold;
        omap3_power_states[OMAP3_STATE_C5].mpu_state = PWRDM_POWER_RET;
        omap3_power_states[OMAP3_STATE_C5].core_state = PWRDM_POWER_RET;
        omap3_power_states[OMAP3_STATE_C5].flags = CPUIDLE_FLAG_TIME_VALID |
                                CPUIDLE_FLAG_CHECK_BM;

        /* C6 . MPU OFF + Core CSWR */
        omap3_power_states[OMAP3_STATE_C6].valid =
                        cpuidle_params_table[OMAP3_STATE_C6].valid;
        omap3_power_states[OMAP3_STATE_C6].type = OMAP3_STATE_C6;
        omap3_power_states[OMAP3_STATE_C6].sleep_latency =
                        cpuidle_params_table[OMAP3_STATE_C6].sleep_latency;
        omap3_power_states[OMAP3_STATE_C6].wakeup_latency =
                        cpuidle_params_table[OMAP3_STATE_C6].wake_latency;
        omap3_power_states[OMAP3_STATE_C6].threshold =
                        cpuidle_params_table[OMAP3_STATE_C6].threshold;
        omap3_power_states[OMAP3_STATE_C6].mpu_state = PWRDM_POWER_OFF;
        omap3_power_states[OMAP3_STATE_C6].core_state = PWRDM_POWER_RET;
        omap3_power_states[OMAP3_STATE_C6].flags = CPUIDLE_FLAG_TIME_VALID |
                                CPUIDLE_FLAG_CHECK_BM;

        /* C7 . MPU OFF + Core OFF */
        omap3_power_states[OMAP3_STATE_C7].valid =
                        cpuidle_params_table[OMAP3_STATE_C7].valid;
        omap3_power_states[OMAP3_STATE_C7].type = OMAP3_STATE_C7;
        omap3_power_states[OMAP3_STATE_C7].sleep_latency =
                        cpuidle_params_table[OMAP3_STATE_C7].sleep_latency;
        omap3_power_states[OMAP3_STATE_C7].wakeup_latency =
                        cpuidle_params_table[OMAP3_STATE_C7].wake_latency;
        omap3_power_states[OMAP3_STATE_C7].threshold =
                        cpuidle_params_table[OMAP3_STATE_C7].threshold;
        omap3_power_states[OMAP3_STATE_C7].mpu_state = PWRDM_POWER_OFF;
        omap3_power_states[OMAP3_STATE_C7].core_state = PWRDM_POWER_OFF;
        omap3_power_states[OMAP3_STATE_C7].flags = CPUIDLE_FLAG_TIME_VALID |
                                CPUIDLE_FLAG_CHECK_BM;

        /*
         * 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)) {
                omap3_power_states[OMAP3_STATE_C7].valid = 0;
                cpuidle_params_table[OMAP3_STATE_C7].valid = 0;
                WARN_ONCE(1, "%s: core off state C7 disabled due to i583\n",
                                __func__);
        }
}

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

/**
 * omap3_idle_init - Init routine for OMAP3 idle
 *
 * Registers the OMAP3 specific cpuidle driver with the cpuidle
 * framework with the valid set of states.
 */
int __init omap3_idle_init(void)
{
        int i, count = 0;
        struct omap3_processor_cx *cx;
        struct cpuidle_state *state;
        struct cpuidle_device *dev;

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

        omap_init_power_states();
        cpuidle_register_driver(&omap3_idle_driver);

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

        for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
                cx = &omap3_power_states[i];
                state = &dev->states[count];

                if (!cx->valid)
                        continue;
                cpuidle_set_statedata(state, cx);
                state->exit_latency = cx->sleep_latency + cx->wakeup_latency;
                state->target_residency = cx->threshold;
                state->flags = cx->flags;
                state->enter = (state->flags & CPUIDLE_FLAG_CHECK_BM) ?
                        omap3_enter_idle_bm : omap3_enter_idle;
                if (cx->type == OMAP3_STATE_C1)
                        dev->safe_state = state;
                sprintf(state->name, "C%d", count+1);
                count++;
        }

        if (!count)
                return -EINVAL;
        dev->state_count = count;

        if (enable_off_mode)
                omap3_cpuidle_update_states(PWRDM_POWER_OFF, PWRDM_POWER_OFF);
        else
                omap3_cpuidle_update_states(PWRDM_POWER_RET, PWRDM_POWER_RET);

        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 */