// SPDX-License-Identifier: GPL-2.0-only
/*
 * OMAP4+ Power Management Routines
 *
 * Copyright (C) 2010-2013 Texas Instruments, Inc.
 * Rajendra Nayak <rnayak@ti.com>
 * Santosh Shilimkar <santosh.shilimkar@ti.com>
 */

#include <linux/pm.h>
#include <linux/suspend.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <asm/system_misc.h>

#include "soc.h"
#include "common.h"
#include "clockdomain.h"
#include "powerdomain.h"
#include "pm.h"

u16 pm44xx_errata;

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

/**
 * struct static_dep_map - Static dependency map
 * @from:       from clockdomain
 * @to:         to clockdomain
  */
struct static_dep_map {
        const char *from;
        const char *to;
};

static u32 cpu_suspend_state = PWRDM_POWER_OFF;

static LIST_HEAD(pwrst_list);

#ifdef CONFIG_SUSPEND
static int omap4_pm_suspend(void)
{
        struct power_state *pwrst;
        int state, ret = 0;
        u32 cpu_id = smp_processor_id();

        /* Save current powerdomain state */
        list_for_each_entry(pwrst, &pwrst_list, node) {
                pwrst->saved_state = pwrdm_read_next_pwrst(pwrst->pwrdm);
                pwrst->saved_logic_state = pwrdm_read_logic_retst(pwrst->pwrdm);
        }

        /* Set targeted power domain states by suspend */
        list_for_each_entry(pwrst, &pwrst_list, node) {
                omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
                pwrdm_set_logic_retst(pwrst->pwrdm, pwrst->next_logic_state);
        }

        /*
         * For MPUSS to hit power domain retention(CSWR or OSWR),
         * CPU0 and CPU1 power domains need to be in OFF or DORMANT state,
         * since CPU power domain CSWR is not supported by hardware
         * Only master CPU follows suspend path. All other CPUs follow
         * CPU hotplug path in system wide suspend. On OMAP4, CPU power
         * domain CSWR is not supported by hardware.
         * More details can be found in OMAP4430 TRM section 4.3.4.2.
         */
        omap4_enter_lowpower(cpu_id, cpu_suspend_state);

        /* Restore next powerdomain state */
        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);
                pwrdm_set_logic_retst(pwrst->pwrdm, pwrst->saved_logic_state);
        }
        if (ret) {
                pr_crit("Could not enter target state in pm_suspend\n");
                /*
                 * OMAP4 chip PM currently works only with certain (newer)
                 * versions of bootloaders. This is due to missing code in the
                 * kernel to properly reset and initialize some devices.
                 * Warn the user about the bootloader version being one of the
                 * possible causes.
                 * http://www.spinics.net/lists/arm-kernel/msg218641.html
                 */
                pr_warn("A possible cause could be an old bootloader - try u-boot >= v2012.07\n");
        } else {
                pr_info("Successfully put all powerdomains to target state\n");
        }

        return 0;
}
#else
#define omap4_pm_suspend NULL
#endif /* CONFIG_SUSPEND */

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

        if (!pwrdm->pwrsts)
                return 0;

        /*
         * Skip CPU0 and CPU1 power domains. CPU1 is programmed
         * through hotplug path and CPU0 explicitly programmed
         * further down in the code path
         */
        if (!strncmp(pwrdm->name, "cpu", 3)) {
                if (IS_PM44XX_ERRATUM(PM_OMAP4_CPU_OSWR_DISABLE))
                        cpu_suspend_state = PWRDM_POWER_RET;
                return 0;
        }

        if (!strncmp(pwrdm->name, "core", 4) ||
            !strncmp(pwrdm->name, "l4per", 5))
                pwrdm_set_logic_retst(pwrdm, PWRDM_POWER_OFF);

        pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
        if (!pwrst)
                return -ENOMEM;

        pwrst->pwrdm = pwrdm;
        pwrst->next_state = pwrdm_get_valid_lp_state(pwrdm, false,
                                                     PWRDM_POWER_RET);
        pwrst->next_logic_state = pwrdm_get_valid_lp_state(pwrdm, true,
                                                           PWRDM_POWER_OFF);

        list_add(&pwrst->node, &pwrst_list);

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

/**
 * omap_default_idle - OMAP4 default ilde routine.'
 *
 * Implements OMAP4 memory, IO ordering requirements which can't be addressed
 * with default cpu_do_idle() hook. Used by all CPUs with !CONFIG_CPU_IDLE and
 * by secondary CPU with CONFIG_CPU_IDLE.
 */
static void omap_default_idle(void)
{
        omap_do_wfi();
}

/*
 * The dynamic dependency between MPUSS -> MEMIF and
 * MPUSS -> L4_PER/L3_* and DUCATI -> L3_* doesn't work as
 * expected. The hardware recommendation is to enable static
 * dependencies for these to avoid system lock ups or random crashes.
 * The L4 wakeup depedency is added to workaround the OCP sync hardware
 * BUG with 32K synctimer which lead to incorrect timer value read
 * from the 32K counter. The BUG applies for GPTIMER1 and WDT2 which
 * are part of L4 wakeup clockdomain.
 */
static const struct static_dep_map omap4_static_dep_map[] = {
        {.from = "mpuss_clkdm", .to = "l3_emif_clkdm"},
        {.from = "mpuss_clkdm", .to = "l3_1_clkdm"},
        {.from = "mpuss_clkdm", .to = "l3_2_clkdm"},
        {.from = "ducati_clkdm", .to = "l3_1_clkdm"},
        {.from = "ducati_clkdm", .to = "l3_2_clkdm"},
        {.from  = NULL} /* TERMINATION */
};

static const struct static_dep_map omap5_dra7_static_dep_map[] = {
        {.from = "mpu_clkdm", .to = "emif_clkdm"},
        {.from  = NULL} /* TERMINATION */
};

/**
 * omap4plus_init_static_deps() - Initialize a static dependency map
 * @map:        Mapping of clock domains
 */
static inline int omap4plus_init_static_deps(const struct static_dep_map *map)
{
        int ret;
        struct clockdomain *from, *to;

        if (!map)
                return 0;

        while (map->from) {
                from = clkdm_lookup(map->from);
                to = clkdm_lookup(map->to);
                if (!from || !to) {
                        pr_err("Failed lookup %s or %s for wakeup dependency\n",
                               map->from, map->to);
                        return -EINVAL;
                }
                ret = clkdm_add_wkdep(from, to);
                if (ret) {
                        pr_err("Failed to add %s -> %s wakeup dependency(%d)\n",
                               map->from, map->to, ret);
                        return ret;
                }

                map++;
        }

        return 0;
}

/**
 * omap4_pm_init_early - Does early initialization necessary for OMAP4+ devices
 *
 * Initializes basic stuff for power management functionality.
 */
int __init omap4_pm_init_early(void)
{
        if (cpu_is_omap446x())
                pm44xx_errata |= PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD;

        if (soc_is_omap54xx() || soc_is_dra7xx())
                pm44xx_errata |= PM_OMAP4_CPU_OSWR_DISABLE;

        return 0;
}

/**
 * omap4_pm_init - Init routine for OMAP4+ devices
 *
 * Initializes all powerdomain and clockdomain target states
 * and all PRCM settings.
 * Return: Returns the error code returned by called functions.
 */
int __init omap4_pm_init(void)
{
        int ret = 0;

        if (omap_rev() == OMAP4430_REV_ES1_0) {
                WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
                return -ENODEV;
        }

        pr_info("Power Management for TI OMAP4+ devices.\n");

        /*
         * OMAP4 chip PM currently works only with certain (newer)
         * versions of bootloaders. This is due to missing code in the
         * kernel to properly reset and initialize some devices.
         * http://www.spinics.net/lists/arm-kernel/msg218641.html
         */
        if (cpu_is_omap44xx())
                pr_warn("OMAP4 PM: u-boot >= v2012.07 is required for full PM support\n");

        ret = pwrdm_for_each(pwrdms_setup, NULL);
        if (ret) {
                pr_err("Failed to setup powerdomains.\n");
                goto err2;
        }

        if (cpu_is_omap44xx())
                ret = omap4plus_init_static_deps(omap4_static_dep_map);
        else if (soc_is_omap54xx() || soc_is_dra7xx())
                ret = omap4plus_init_static_deps(omap5_dra7_static_dep_map);

        if (ret) {
                pr_err("Failed to initialise static dependencies.\n");
                goto err2;
        }

        ret = omap4_mpuss_init();
        if (ret) {
                pr_err("Failed to initialise OMAP4 MPUSS\n");
                goto err2;
        }

        (void) clkdm_for_each(omap_pm_clkdms_setup, NULL);

        omap_common_suspend_init(omap4_pm_suspend);

        /* Overwrite the default cpu_do_idle() */
        arm_pm_idle = omap_default_idle;

        if (cpu_is_omap44xx() || soc_is_omap54xx())
                omap4_idle_init();

err2:
        return ret;
}