// SPDX-License-Identifier: GPL-2.0
/* power.c: Power management driver.
 *
 * Copyright (C) 1999, 2007, 2008 David S. Miller (davem@davemloft.net)
 */

#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/reboot.h>
#include <linux/of.h>
#include <linux/platform_device.h>

#include <asm/prom.h>
#include <asm/io.h>

static void __iomem *power_reg;

static irqreturn_t power_handler(int irq, void *dev_id)
{
        orderly_poweroff(true);

        /* FIXME: Check registers for status... */
        return IRQ_HANDLED;
}

static int has_button_interrupt(unsigned int irq, struct device_node *dp)
{
        if (irq == 0xffffffff)
                return 0;
        if (!of_property_read_bool(dp, "button"))
                return 0;

        return 1;
}

static int power_probe(struct platform_device *op)
{
        struct resource *res = &op->resource[0];
        unsigned int irq = op->archdata.irqs[0];

        power_reg = of_ioremap(res, 0, 0x4, "power");

        printk(KERN_INFO "%pOFn: Control reg at %llx\n",
               op->dev.of_node, res->start);

        if (has_button_interrupt(irq, op->dev.of_node)) {
                if (request_irq(irq,
                                power_handler, 0, "power", NULL) < 0)
                        printk(KERN_ERR "power: Cannot setup IRQ handler.\n");
        }

        return 0;
}

static const struct of_device_id power_match[] = {
        {
                .name = "power",
        },
        {},
};

static struct platform_driver power_driver = {
        .probe          = power_probe,
        .driver = {
                .name = "power",
                .of_match_table = power_match,
        },
};

builtin_platform_driver(power_driver);