/*
 * OMAP3 Power Management Routines
 *
 * Copyright (C) 2006-2008 Nokia Corporation
 * Tony Lindgren <tony@atomide.com>
 * Jouni Hogander
 *
 * Copyright (C) 2007 Texas Instruments, Inc.
 * Rajendra Nayak <rnayak@ti.com>
 *
 * Copyright (C) 2005 Texas Instruments, Inc.
 * Richard Woodruff <r-woodruff2@ti.com>
 *
 * Based on pm.c for omap1
 *
 * 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/pm.h>
#include <linux/suspend.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/omap-dma.h>
#include <linux/omap-gpmc.h>
#include <linux/platform_data/gpio-omap.h>

#include <trace/events/power.h>

#include <asm/fncpy.h>
#include <asm/suspend.h>
#include <asm/system_misc.h>

#include "clockdomain.h"
#include "powerdomain.h"
#include "soc.h"
#include "common.h"
#include "cm3xxx.h"
#include "cm-regbits-34xx.h"
#include "prm-regbits-34xx.h"
#include "prm3xxx.h"
#include "pm.h"
#include "sdrc.h"
#include "omap-secure.h"
#include "sram.h"
#include "control.h"
#include "vc.h"

/* pm34xx errata defined in pm.h */
u16 pm34xx_errata;

struct power_state {
        struct powerdomain *pwrdm;
        u32 next_state;
#ifdef CONFIG_SUSPEND
        u32 saved_state;
#endif
        struct list_head node;
};

static LIST_HEAD(pwrst_list);

void (*omap3_do_wfi_sram)(void);

static struct powerdomain *mpu_pwrdm, *neon_pwrdm;
static struct powerdomain *core_pwrdm, *per_pwrdm;

static void omap3_core_save_context(void)
{
        omap3_ctrl_save_padconf();

        /*
         * Force write last pad into memory, as this can fail in some
         * cases according to errata 1.157, 1.185
         */
        omap_ctrl_writel(omap_ctrl_readl(OMAP343X_PADCONF_ETK_D14),
                OMAP343X_CONTROL_MEM_WKUP + 0x2a0);

        /* Save the Interrupt controller context */
        omap_intc_save_context();
        /* Save the GPMC context */
        omap3_gpmc_save_context();
        /* Save the system control module context, padconf already save above*/
        omap3_control_save_context();
        omap_dma_global_context_save();
}

static void omap3_core_restore_context(void)
{
        /* Restore the control module context, padconf restored by h/w */
        omap3_control_restore_context();
        /* Restore the GPMC context */
        omap3_gpmc_restore_context();
        /* Restore the interrupt controller context */
        omap_intc_restore_context();
        omap_dma_global_context_restore();
}

/*
 * FIXME: This function should be called before entering off-mode after
 * OMAP3 secure services have been accessed. Currently it is only called
 * once during boot sequence, but this works as we are not using secure
 * services.
 */
static void omap3_save_secure_ram_context(void)
{
        u32 ret;
        int mpu_next_state = pwrdm_read_next_pwrst(mpu_pwrdm);

        if (omap_type() != OMAP2_DEVICE_TYPE_GP) {
                /*
                 * MPU next state must be set to POWER_ON temporarily,
                 * otherwise the WFI executed inside the ROM code
                 * will hang the system.
                 */
                pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_ON);
                ret = omap3_save_secure_ram(omap3_secure_ram_storage,
                                            OMAP3_SAVE_SECURE_RAM_SZ);
                pwrdm_set_next_pwrst(mpu_pwrdm, mpu_next_state);
                /* Following is for error tracking, it should not happen */
                if (ret) {
                        pr_err("save_secure_sram() returns %08x\n", ret);
                        while (1)
                                ;
                }
        }
}

static irqreturn_t _prcm_int_handle_io(int irq, void *unused)
{
        int c;

        c = omap_prm_clear_mod_irqs(WKUP_MOD, 1, OMAP3430_ST_IO_MASK |
                                    OMAP3430_ST_IO_CHAIN_MASK);

        return c ? IRQ_HANDLED : IRQ_NONE;
}

static irqreturn_t _prcm_int_handle_wakeup(int irq, void *unused)
{
        int c;

        /*
         * Clear all except ST_IO and ST_IO_CHAIN for wkup module,
         * these are handled in a separate handler to avoid acking
         * IO events before parsing in mux code
         */
        c = omap_prm_clear_mod_irqs(WKUP_MOD, 1, ~(OMAP3430_ST_IO_MASK |
                                                   OMAP3430_ST_IO_CHAIN_MASK));
        c += omap_prm_clear_mod_irqs(CORE_MOD, 1, ~0);
        c += omap_prm_clear_mod_irqs(OMAP3430_PER_MOD, 1, ~0);
        if (omap_rev() > OMAP3430_REV_ES1_0) {
                c += omap_prm_clear_mod_irqs(CORE_MOD, 3, ~0);
                c += omap_prm_clear_mod_irqs(OMAP3430ES2_USBHOST_MOD, 1, ~0);
        }

        return c ? IRQ_HANDLED : IRQ_NONE;
}

static void omap34xx_save_context(u32 *save)
{
        u32 val;

        /* Read Auxiliary Control Register */
        asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (val));
        *save++ = 1;
        *save++ = val;

        /* Read L2 AUX ctrl register */
        asm("mrc p15, 1, %0, c9, c0, 2" : "=r" (val));
        *save++ = 1;
        *save++ = val;
}

static int omap34xx_do_sram_idle(unsigned long save_state)
{
        omap34xx_cpu_suspend(save_state);
        return 0;
}

void omap_sram_idle(void)
{
        /* Variable to tell what needs to be saved and restored
         * in omap_sram_idle*/
        /* save_state = 0 => Nothing to save and restored */
        /* save_state = 1 => Only L1 and logic lost */
        /* save_state = 2 => Only L2 lost */
        /* save_state = 3 => L1, L2 and logic lost */
        int save_state = 0;
        int mpu_next_state = PWRDM_POWER_ON;
        int per_next_state = PWRDM_POWER_ON;
        int core_next_state = PWRDM_POWER_ON;
        int per_going_off;
        u32 sdrc_pwr = 0;

        mpu_next_state = pwrdm_read_next_pwrst(mpu_pwrdm);
        switch (mpu_next_state) {
        case PWRDM_POWER_ON:
        case PWRDM_POWER_RET:
                /* No need to save context */
                save_state = 0;
                break;
        case PWRDM_POWER_OFF:
                save_state = 3;
                break;
        default:
                /* Invalid state */
                pr_err("Invalid mpu state in sram_idle\n");
                return;
        }

        /* NEON control */
        if (pwrdm_read_pwrst(neon_pwrdm) == PWRDM_POWER_ON)
                pwrdm_set_next_pwrst(neon_pwrdm, mpu_next_state);

        /* Enable IO-PAD and IO-CHAIN wakeups */
        per_next_state = pwrdm_read_next_pwrst(per_pwrdm);
        core_next_state = pwrdm_read_next_pwrst(core_pwrdm);

        pwrdm_pre_transition(NULL);

        /* PER */
        if (per_next_state < PWRDM_POWER_ON) {
                per_going_off = (per_next_state == PWRDM_POWER_OFF) ? 1 : 0;
                omap2_gpio_prepare_for_idle(per_going_off);
        }

        /* CORE */
        if (core_next_state < PWRDM_POWER_ON) {
                if (core_next_state == PWRDM_POWER_OFF) {
                        omap3_core_save_context();
                        omap3_cm_save_context();
                }
        }

        /* Configure PMIC signaling for I2C4 or sys_off_mode */
        omap3_vc_set_pmic_signaling(core_next_state);

        omap3_intc_prepare_idle();

        /*
         * On EMU/HS devices ROM code restores a SRDC value
         * from scratchpad which has automatic self refresh on timeout
         * of AUTO_CNT = 1 enabled. This takes care of erratum ID i443.
         * Hence store/restore the SDRC_POWER register here.
         */
        if (cpu_is_omap3430() && omap_rev() >= OMAP3430_REV_ES3_0 &&
            (omap_type() == OMAP2_DEVICE_TYPE_EMU ||
             omap_type() == OMAP2_DEVICE_TYPE_SEC) &&
            core_next_state == PWRDM_POWER_OFF)
                sdrc_pwr = sdrc_read_reg(SDRC_POWER);

        /*
         * omap3_arm_context is the location where some ARM context
         * get saved. The rest is placed on the stack, and restored
         * from there before resuming.
         */
        if (save_state)
                omap34xx_save_context(omap3_arm_context);
        if (save_state == 1 || save_state == 3)
                cpu_suspend(save_state, omap34xx_do_sram_idle);
        else
                omap34xx_do_sram_idle(save_state);

        /* Restore normal SDRC POWER settings */
        if (cpu_is_omap3430() && omap_rev() >= OMAP3430_REV_ES3_0 &&
            (omap_type() == OMAP2_DEVICE_TYPE_EMU ||
             omap_type() == OMAP2_DEVICE_TYPE_SEC) &&
            core_next_state == PWRDM_POWER_OFF)
                sdrc_write_reg(sdrc_pwr, SDRC_POWER);

        /* CORE */
        if (core_next_state < PWRDM_POWER_ON &&
            pwrdm_read_prev_pwrst(core_pwrdm) == PWRDM_POWER_OFF) {
                omap3_core_restore_context();
                omap3_cm_restore_context();
                omap3_sram_restore_context();
                omap2_sms_restore_context();
        } else {
                /*
                 * In off-mode resume path above, omap3_core_restore_context
                 * also handles the INTC autoidle restore done here so limit
                 * this to non-off mode resume paths so we don't do it twice.
                 */
                omap3_intc_resume_idle();
        }

        pwrdm_post_transition(NULL);

        /* PER */
        if (per_next_state < PWRDM_POWER_ON)
                omap2_gpio_resume_after_idle();
}

static void omap3_pm_idle(void)
{
        if (omap_irq_pending())
                return;

        trace_cpu_idle_rcuidle(1, smp_processor_id());

        omap_sram_idle();

        trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}

#ifdef CONFIG_SUSPEND
static int omap3_pm_suspend(void)
{
        struct power_state *pwrst;
        int state, ret = 0;

        /* Read current next_pwrsts */
        list_for_each_entry(pwrst, &pwrst_list, node)
                pwrst->saved_state = pwrdm_read_next_pwrst(pwrst->pwrdm);
        /* Set ones wanted by suspend */
        list_for_each_entry(pwrst, &pwrst_list, node) {
                if (omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state))
                        goto restore;
                if (pwrdm_clear_all_prev_pwrst(pwrst->pwrdm))
                        goto restore;
        }

        omap3_intc_suspend();

        omap_sram_idle();

restore:
        /* Restore next_pwrsts */
        list_for_each_entry(pwrst, &pwrst_list, node) {
                state = pwrdm_read_prev_pwrst(pwrst->pwrdm);
                if (state > pwrst->next_state) {
                        pr_info("Powerdomain (%s) didn't enter target state %d\n",
                                pwrst->pwrdm->name, pwrst->next_state);
                        ret = -1;
                }
                omap_set_pwrdm_state(pwrst->pwrdm, pwrst->saved_state);
        }
        if (ret)
                pr_err("Could not enter target state in pm_suspend\n");
        else
                pr_info("Successfully put all powerdomains to target state\n");

        return ret;
}
#else
#define omap3_pm_suspend NULL
#endif /* CONFIG_SUSPEND */

static void __init prcm_setup_regs(void)
{
        omap3_ctrl_init();

        omap3_prm_init_pm(cpu_is_omap3630(), omap3_has_iva());
}

void omap3_pm_off_mode_enable(int enable)
{
        struct power_state *pwrst;
        u32 state;

        if (enable)
                state = PWRDM_POWER_OFF;
        else
                state = PWRDM_POWER_RET;

        list_for_each_entry(pwrst, &pwrst_list, node) {
                if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583) &&
                                pwrst->pwrdm == core_pwrdm &&
                                state == PWRDM_POWER_OFF) {
                        pwrst->next_state = PWRDM_POWER_RET;
                        pr_warn("%s: Core OFF disabled due to errata i583\n",
                                __func__);
                } else {
                        pwrst->next_state = state;
                }
                omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
        }
}

int omap3_pm_get_suspend_state(struct powerdomain *pwrdm)
{
        struct power_state *pwrst;

        list_for_each_entry(pwrst, &pwrst_list, node) {
                if (pwrst->pwrdm == pwrdm)
                        return pwrst->next_state;
        }
        return -EINVAL;
}

int omap3_pm_set_suspend_state(struct powerdomain *pwrdm, int state)
{
        struct power_state *pwrst;

        list_for_each_entry(pwrst, &pwrst_list, node) {
                if (pwrst->pwrdm == pwrdm) {
                        pwrst->next_state = state;
                        return 0;
                }
        }
        return -EINVAL;
}

static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
{
        struct power_state *pwrst;

        if (!pwrdm->pwrsts)
                return 0;

        pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
        if (!pwrst)
                return -ENOMEM;
        pwrst->pwrdm = pwrdm;
        pwrst->next_state = PWRDM_POWER_RET;
        list_add(&pwrst->node, &pwrst_list);

        if (pwrdm_has_hdwr_sar(pwrdm))
                pwrdm_enable_hdwr_sar(pwrdm);

        return omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
}

/*
 * Push functions to SRAM
 *
 * The minimum set of functions is pushed to SRAM for execution:
 * - omap3_do_wfi for erratum i581 WA,
 */
void omap_push_sram_idle(void)
{
        omap3_do_wfi_sram = omap_sram_push(omap3_do_wfi, omap3_do_wfi_sz);
}

static void __init pm_errata_configure(void)
{
        if (cpu_is_omap3630()) {
                pm34xx_errata |= PM_RTA_ERRATUM_i608;
                /* Enable the l2 cache toggling in sleep logic */
                enable_omap3630_toggle_l2_on_restore();
                if (omap_rev() < OMAP3630_REV_ES1_2)
                        pm34xx_errata |= (PM_SDRC_WAKEUP_ERRATUM_i583 |
                                          PM_PER_MEMORIES_ERRATUM_i582);
        } else if (cpu_is_omap34xx()) {
                pm34xx_errata |= PM_PER_MEMORIES_ERRATUM_i582;
        }
}

int __init omap3_pm_init(void)
{
        struct power_state *pwrst, *tmp;
        struct clockdomain *neon_clkdm, *mpu_clkdm, *per_clkdm, *wkup_clkdm;
        int ret;

        if (!omap3_has_io_chain_ctrl())
                pr_warn("PM: no software I/O chain control; some wakeups may be lost\n");

        pm_errata_configure();

        /* XXX prcm_setup_regs needs to be before enabling hw
         * supervised mode for powerdomains */
        prcm_setup_regs();

        ret = request_irq(omap_prcm_event_to_irq("wkup"),
                _prcm_int_handle_wakeup, IRQF_NO_SUSPEND, "pm_wkup", NULL);

        if (ret) {
                pr_err("pm: Failed to request pm_wkup irq\n");
                goto err1;
        }

        /* IO interrupt is shared with mux code */
        ret = request_irq(omap_prcm_event_to_irq("io"),
                _prcm_int_handle_io, IRQF_SHARED | IRQF_NO_SUSPEND, "pm_io",
                omap3_pm_init);

        if (ret) {
                pr_err("pm: Failed to request pm_io irq\n");
                goto err2;
        }

        ret = pwrdm_for_each(pwrdms_setup, NULL);
        if (ret) {
                pr_err("Failed to setup powerdomains\n");
                goto err3;
        }

        (void) clkdm_for_each(omap_pm_clkdms_setup, NULL);

        mpu_pwrdm = pwrdm_lookup("mpu_pwrdm");
        if (mpu_pwrdm == NULL) {
                pr_err("Failed to get mpu_pwrdm\n");
                ret = -EINVAL;
                goto err3;
        }

        neon_pwrdm = pwrdm_lookup("neon_pwrdm");
        per_pwrdm = pwrdm_lookup("per_pwrdm");
        core_pwrdm = pwrdm_lookup("core_pwrdm");

        neon_clkdm = clkdm_lookup("neon_clkdm");
        mpu_clkdm = clkdm_lookup("mpu_clkdm");
        per_clkdm = clkdm_lookup("per_clkdm");
        wkup_clkdm = clkdm_lookup("wkup_clkdm");

        omap_common_suspend_init(omap3_pm_suspend);

        arm_pm_idle = omap3_pm_idle;
        omap3_idle_init();

        /*
         * RTA is disabled during initialization as per erratum i608
         * it is safer to disable RTA by the bootloader, but we would like
         * to be doubly sure here and prevent any mishaps.
         */
        if (IS_PM34XX_ERRATUM(PM_RTA_ERRATUM_i608))
                omap3630_ctrl_disable_rta();

        /*
         * The UART3/4 FIFO and the sidetone memory in McBSP2/3 are
         * not correctly reset when the PER powerdomain comes back
         * from OFF or OSWR when the CORE powerdomain is kept active.
         * See OMAP36xx Erratum i582 "PER Domain reset issue after
         * Domain-OFF/OSWR Wakeup".  This wakeup dependency is not a
         * complete workaround.  The kernel must also prevent the PER
         * powerdomain from going to OSWR/OFF while the CORE
         * powerdomain is not going to OSWR/OFF.  And if PER last
         * power state was off while CORE last power state was ON, the
         * UART3/4 and McBSP2/3 SIDETONE devices need to run a
         * self-test using their loopback tests; if that fails, those
         * devices are unusable until the PER/CORE can complete a transition
         * from ON to OSWR/OFF and then back to ON.
         *
         * XXX Technically this workaround is only needed if off-mode
         * or OSWR is enabled.
         */
        if (IS_PM34XX_ERRATUM(PM_PER_MEMORIES_ERRATUM_i582))
                clkdm_add_wkdep(per_clkdm, wkup_clkdm);

        clkdm_add_wkdep(neon_clkdm, mpu_clkdm);
        if (omap_type() != OMAP2_DEVICE_TYPE_GP) {
                omap3_secure_ram_storage =
                        kmalloc(OMAP3_SAVE_SECURE_RAM_SZ, GFP_KERNEL);
                if (!omap3_secure_ram_storage)
                        pr_err("Memory allocation failed when allocating for secure sram context\n");

                local_irq_disable();

                omap_dma_global_context_save();
                omap3_save_secure_ram_context();
                omap_dma_global_context_restore();

                local_irq_enable();
        }

        omap3_save_scratchpad_contents();
        return ret;

err3:
        list_for_each_entry_safe(pwrst, tmp, &pwrst_list, node) {
                list_del(&pwrst->node);
                kfree(pwrst);
        }
        free_irq(omap_prcm_event_to_irq("io"), omap3_pm_init);
err2:
        free_irq(omap_prcm_event_to_irq("wkup"), NULL);
err1:
        return ret;
}