// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * pata_ns87410.c       - National Semiconductor 87410 PATA for new ATA layer
 *                        (C) 2006 Red Hat Inc
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>

#define DRV_NAME "pata_ns87410"
#define DRV_VERSION "0.4.6"

/**
 *      ns87410_pre_reset               -       probe begin
 *      @link: ATA link
 *      @deadline: deadline jiffies for the operation
 *
 *      Check enabled ports
 */

static int ns87410_pre_reset(struct ata_link *link, unsigned long deadline)
{
        struct ata_port *ap = link->ap;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        static const struct pci_bits ns87410_enable_bits[] = {
                { 0x43, 1, 0x08, 0x08 },
                { 0x47, 1, 0x08, 0x08 }
        };

        if (!pci_test_config_bits(pdev, &ns87410_enable_bits[ap->port_no]))
                return -ENOENT;

        return ata_sff_prereset(link, deadline);
}

/**
 *      ns87410_set_piomode     -       set initial PIO mode data
 *      @ap: ATA interface
 *      @adev: ATA device
 *
 *      Program timing data. This is kept per channel not per device,
 *      and only affects the data port.
 */

static void ns87410_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int port = 0x40 + 4 * ap->port_no;
        u8 idetcr, idefr;
        struct ata_timing at;

        static const u8 activebits[15] = {
                0, 1, 2, 3, 4,
                5, 5, 6, 6, 6,
                6, 7, 7, 7, 7
        };

        static const u8 recoverbits[12] = {
                0, 1, 2, 3, 4, 5, 6, 6, 7, 7, 7, 7
        };

        pci_read_config_byte(pdev, port + 3, &idefr);

        if (ata_pio_need_iordy(adev))
                idefr |= 0x04;  /* IORDY enable */
        else
                idefr &= ~0x04;

        if (ata_timing_compute(adev, adev->pio_mode, &at, 30303, 1) < 0) {
                dev_err(&pdev->dev, "unknown mode %d\n", adev->pio_mode);
                return;
        }

        at.active = clamp_val(at.active, 2, 16) - 2;
        at.setup = clamp_val(at.setup, 1, 4) - 1;
        at.recover = clamp_val(at.recover, 1, 12) - 1;

        idetcr = (at.setup << 6) | (recoverbits[at.recover] << 3) | activebits[at.active];

        pci_write_config_byte(pdev, port, idetcr);
        pci_write_config_byte(pdev, port + 3, idefr);
        /* We use ap->private_data as a pointer to the device currently
           loaded for timing */
        ap->private_data = adev;
}

/**
 *      ns87410_qc_issue        -       command issue
 *      @qc: command pending
 *
 *      Called when the libata layer is about to issue a command. We wrap
 *      this interface so that we can load the correct ATA timings if
 *      necessary.
 */

static unsigned int ns87410_qc_issue(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct ata_device *adev = qc->dev;

        /* If modes have been configured and the channel data is not loaded
           then load it. We have to check if pio_mode is set as the core code
           does not set adev->pio_mode to XFER_PIO_0 while probing as would be
           logical */

        if (adev->pio_mode && adev != ap->private_data)
                ns87410_set_piomode(ap, adev);

        return ata_sff_qc_issue(qc);
}

static const struct scsi_host_template ns87410_sht = {
        ATA_PIO_SHT(DRV_NAME),
};

static struct ata_port_operations ns87410_port_ops = {
        .inherits       = &ata_sff_port_ops,
        .qc_issue       = ns87410_qc_issue,
        .cable_detect   = ata_cable_40wire,
        .set_piomode    = ns87410_set_piomode,
        .reset.prereset = ns87410_pre_reset,
};

static int ns87410_init_one(struct pci_dev *dev, const struct pci_device_id *id)
{
        static const struct ata_port_info info = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO3,
                .port_ops = &ns87410_port_ops
        };
        const struct ata_port_info *ppi[] = { &info, NULL };
        return ata_pci_sff_init_one(dev, ppi, &ns87410_sht, NULL, 0);
}

static const struct pci_device_id ns87410[] = {
        { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_87410), },

        { },
};

static struct pci_driver ns87410_pci_driver = {
        .name           = DRV_NAME,
        .id_table       = ns87410,
        .probe          = ns87410_init_one,
        .remove         = ata_pci_remove_one,
#ifdef CONFIG_PM_SLEEP
        .suspend        = ata_pci_device_suspend,
        .resume         = ata_pci_device_resume,
#endif
};

module_pci_driver(ns87410_pci_driver);

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for Nat Semi 87410");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, ns87410);
MODULE_VERSION(DRV_VERSION);