// SPDX-License-Identifier: GPL-2.0-only
/*
 * AB8500 system control driver
 *
 * Copyright (C) ST-Ericsson SA 2010
 * Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com> for ST Ericsson.
 */

#include <linux/err.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/reboot.h>
#include <linux/signal.h>
#include <linux/power_supply.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/abx500/ab8500.h>
#include <linux/mfd/abx500/ab8500-sysctrl.h>

/* RtcCtrl bits */
#define AB8500_ALARM_MIN_LOW  0x08
#define AB8500_ALARM_MIN_MID 0x09
#define RTC_CTRL 0x0B
#define RTC_ALARM_ENABLE 0x4

static struct device *sysctrl_dev;

static void ab8500_power_off(void)
{
        sigset_t old;
        sigset_t all;
        static const char * const pss[] = {"ab8500_ac", "ab8500_usb"};
        int i;
        bool charger_present = false;
        union power_supply_propval val;
        struct power_supply *psy;
        int ret;

        if (sysctrl_dev == NULL) {
                pr_err("%s: sysctrl not initialized\n", __func__);
                return;
        }

        /*
         * If we have a charger connected and we're powering off,
         * reboot into charge-only mode.
         */

        for (i = 0; i < ARRAY_SIZE(pss); i++) {
                psy = power_supply_get_by_name(pss[i]);
                if (!psy)
                        continue;

                ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_ONLINE,
                                &val);
                power_supply_put(psy);

                if (!ret && val.intval) {
                        charger_present = true;
                        break;
                }
        }

        if (!charger_present)
                goto shutdown;

        /* Check if battery is known */
        psy = power_supply_get_by_name("ab8500_btemp");
        if (psy) {
                ret = power_supply_get_property(psy,
                                POWER_SUPPLY_PROP_TECHNOLOGY, &val);
                if (!ret && val.intval != POWER_SUPPLY_TECHNOLOGY_UNKNOWN) {
                        pr_info("Charger '%s' is connected with known battery",
                                pss[i]);
                        pr_info(" - Rebooting.\n");
                        machine_restart("charging");
                }
                power_supply_put(psy);
        }

shutdown:
        sigfillset(&all);

        if (!sigprocmask(SIG_BLOCK, &all, &old)) {
                (void)ab8500_sysctrl_set(AB8500_STW4500CTRL1,
                                         AB8500_STW4500CTRL1_SWOFF |
                                         AB8500_STW4500CTRL1_SWRESET4500N);
                (void)sigprocmask(SIG_SETMASK, &old, NULL);
        }
}

static inline bool valid_bank(u8 bank)
{
        return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
                (bank == AB8500_SYS_CTRL2_BLOCK));
}

int ab8500_sysctrl_read(u16 reg, u8 *value)
{
        u8 bank;

        if (sysctrl_dev == NULL)
                return -EPROBE_DEFER;

        bank = (reg >> 8);
        if (!valid_bank(bank))
                return -EINVAL;

        return abx500_get_register_interruptible(sysctrl_dev, bank,
                (u8)(reg & 0xFF), value);
}
EXPORT_SYMBOL(ab8500_sysctrl_read);

int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
{
        u8 bank;

        if (sysctrl_dev == NULL)
                return -EPROBE_DEFER;

        bank = (reg >> 8);
        if (!valid_bank(bank)) {
                pr_err("invalid bank\n");
                return -EINVAL;
        }

        return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
                (u8)(reg & 0xFF), mask, value);
}
EXPORT_SYMBOL(ab8500_sysctrl_write);

static int ab8500_sysctrl_probe(struct platform_device *pdev)
{
        sysctrl_dev = &pdev->dev;

        if (!pm_power_off)
                pm_power_off = ab8500_power_off;

        return 0;
}

static void ab8500_sysctrl_remove(struct platform_device *pdev)
{
        sysctrl_dev = NULL;

        if (pm_power_off == ab8500_power_off)
                pm_power_off = NULL;
}

static const struct of_device_id ab8500_sysctrl_match[] = {
        { .compatible = "stericsson,ab8500-sysctrl", },
        {}
};

static struct platform_driver ab8500_sysctrl_driver = {
        .driver = {
                .name = "ab8500-sysctrl",
                .of_match_table = ab8500_sysctrl_match,
        },
        .probe = ab8500_sysctrl_probe,
        .remove = ab8500_sysctrl_remove,
};

static int __init ab8500_sysctrl_init(void)
{
        return platform_driver_register(&ab8500_sysctrl_driver);
}
arch_initcall(ab8500_sysctrl_init);