// SPDX-License-Identifier: GPL-2.0-only
/*
 * OF-platform PATA driver
 *
 * Copyright (c) 2007  MontaVista Software, Inc.
 *                     Anton Vorontsov <avorontsov@ru.mvista.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/ata_platform.h>
#include <linux/libata.h>

#define DRV_NAME "pata_of_platform"

static const struct scsi_host_template pata_platform_sht = {
        ATA_PIO_SHT(DRV_NAME),
};

static int pata_of_platform_probe(struct platform_device *ofdev)
{
        int ret;
        struct device_node *dn = ofdev->dev.of_node;
        struct resource io_res;
        struct resource ctl_res;
        struct resource irq_res;
        unsigned int reg_shift = 0;
        int pio_mode = 0;
        int pio_mask;
        bool use16bit;
        int irq;

        ret = of_address_to_resource(dn, 0, &io_res);
        if (ret) {
                dev_err(&ofdev->dev, "can't get IO address from "
                        "device tree\n");
                return -EINVAL;
        }

        ret = of_address_to_resource(dn, 1, &ctl_res);
        if (ret) {
                dev_err(&ofdev->dev, "can't get CTL address from "
                        "device tree\n");
                return -EINVAL;
        }

        memset(&irq_res, 0, sizeof(irq_res));

        irq = platform_get_irq_optional(ofdev, 0);
        if (irq < 0 && irq != -ENXIO)
                return irq;
        if (irq > 0) {
                irq_res.start = irq;
                irq_res.end = irq;
        }

        of_property_read_u32(dn, "reg-shift", &reg_shift);

        if (!of_property_read_u32(dn, "pio-mode", &pio_mode)) {
                if (pio_mode > 6) {
                        dev_err(&ofdev->dev, "invalid pio-mode\n");
                        return -EINVAL;
                }
        } else {
                dev_info(&ofdev->dev, "pio-mode unspecified, assuming PIO0\n");
        }

        use16bit = of_property_read_bool(dn, "ata-generic,use16bit");

        pio_mask = 1 << pio_mode;
        pio_mask |= (1 << pio_mode) - 1;

        return __pata_platform_probe(&ofdev->dev, &io_res, &ctl_res, irq > 0 ? &irq_res : NULL,
                                     reg_shift, pio_mask, &pata_platform_sht,
                                     use16bit);
}

static const struct of_device_id pata_of_platform_match[] = {
        { .compatible = "ata-generic", },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, pata_of_platform_match);

static struct platform_driver pata_of_platform_driver = {
        .driver = {
                .name = DRV_NAME,
                .of_match_table = pata_of_platform_match,
        },
        .probe          = pata_of_platform_probe,
        .remove         = ata_platform_remove_one,
};

module_platform_driver(pata_of_platform_driver);

MODULE_DESCRIPTION("OF-platform PATA driver");
MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
MODULE_LICENSE("GPL");