/*
 * Copyright (C) 1997-1998      Mark Lord <mlord@pobox.com>
 * Copyright (C) 1998           Eddie C. Dost <ecd@skynet.be>
 * Copyright (C) 1999-2000      Andre Hedrick <andre@linux-ide.org>
 * Copyright (C) 2004           Grant Grundler <grundler at parisc-linux.org>
 *
 * Inspired by an earlier effort from David S. Miller <davem@redhat.com>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/init.h>

#include <asm/io.h>

#define DRV_NAME "ns87415"

#ifdef CONFIG_SUPERIO
/* SUPERIO 87560 is a PoS chip that NatSem denies exists.
 * Unfortunately, it's built-in on all Astro-based PA-RISC workstations
 * which use the integrated NS87514 cell for CD-ROM support.
 * i.e we have to support for CD-ROM installs.
 * See drivers/parisc/superio.c for more gory details.
 */
#include <asm/superio.h>

#define SUPERIO_IDE_MAX_RETRIES 25

/* Because of a defect in Super I/O, all reads of the PCI DMA status 
 * registers, IDE status register and the IDE select register need to be 
 * retried
 */
static u8 superio_ide_inb (unsigned long port)
{
        u8 tmp;
        int retries = SUPERIO_IDE_MAX_RETRIES;

        /* printk(" [ reading port 0x%x with retry ] ", port); */

        do {
                tmp = inb(port);
                if (tmp == 0)
                        udelay(50);
        } while (tmp == 0 && retries-- > 0);

        return tmp;
}

static u8 superio_read_status(ide_hwif_t *hwif)
{
        return superio_ide_inb(hwif->io_ports.status_addr);
}

static u8 superio_dma_sff_read_status(ide_hwif_t *hwif)
{
        return superio_ide_inb(hwif->dma_base + ATA_DMA_STATUS);
}

static void superio_tf_read(ide_drive_t *drive, struct ide_taskfile *tf,
                            u8 valid)
{
        struct ide_io_ports *io_ports = &drive->hwif->io_ports;

        if (valid & IDE_VALID_ERROR)
                tf->error  = inb(io_ports->feature_addr);
        if (valid & IDE_VALID_NSECT)
                tf->nsect  = inb(io_ports->nsect_addr);
        if (valid & IDE_VALID_LBAL)
                tf->lbal   = inb(io_ports->lbal_addr);
        if (valid & IDE_VALID_LBAM)
                tf->lbam   = inb(io_ports->lbam_addr);
        if (valid & IDE_VALID_LBAH)
                tf->lbah   = inb(io_ports->lbah_addr);
        if (valid & IDE_VALID_DEVICE)
                tf->device = superio_ide_inb(io_ports->device_addr);
}

static void ns87415_dev_select(ide_drive_t *drive);

static const struct ide_tp_ops superio_tp_ops = {
        .exec_command           = ide_exec_command,
        .read_status            = superio_read_status,
        .read_altstatus         = ide_read_altstatus,
        .write_devctl           = ide_write_devctl,

        .dev_select             = ns87415_dev_select,
        .tf_load                = ide_tf_load,
        .tf_read                = superio_tf_read,

        .input_data             = ide_input_data,
        .output_data            = ide_output_data,
};

static void superio_init_iops(struct hwif_s *hwif)
{
        struct pci_dev *pdev = to_pci_dev(hwif->dev);
        u32 dma_stat;
        u8 port = hwif->channel, tmp;

        dma_stat = (pci_resource_start(pdev, 4) & ~3) + (!port ? 2 : 0xa);

        /* Clear error/interrupt, enable dma */
        tmp = superio_ide_inb(dma_stat);
        outb(tmp | 0x66, dma_stat);
}
#else
#define superio_dma_sff_read_status ide_dma_sff_read_status
#endif

static unsigned int ns87415_count = 0, ns87415_control[MAX_HWIFS] = { 0 };

/*
 * This routine either enables/disables (according to IDE_DFLAG_PRESENT)
 * the IRQ associated with the port,
 * and selects either PIO or DMA handshaking for the next I/O operation.
 */
static void ns87415_prepare_drive (ide_drive_t *drive, unsigned int use_dma)
{
        ide_hwif_t *hwif = drive->hwif;
        struct pci_dev *dev = to_pci_dev(hwif->dev);
        unsigned int bit, other, new, *old = (unsigned int *) hwif->select_data;
        unsigned long flags;

        local_irq_save(flags);
        new = *old;

        /* Adjust IRQ enable bit */
        bit = 1 << (8 + hwif->channel);

        if (drive->dev_flags & IDE_DFLAG_PRESENT)
                new &= ~bit;
        else
                new |= bit;

        /* Select PIO or DMA, DMA may only be selected for one drive/channel. */
        bit   = 1 << (20 + (drive->dn & 1) + (hwif->channel << 1));
        other = 1 << (20 + (1 - (drive->dn & 1)) + (hwif->channel << 1));
        new = use_dma ? ((new & ~other) | bit) : (new & ~bit);

        if (new != *old) {
                unsigned char stat;

                /*
                 * Don't change DMA engine settings while Write Buffers
                 * are busy.
                 */
                (void) pci_read_config_byte(dev, 0x43, &stat);
                while (stat & 0x03) {
                        udelay(1);
                        (void) pci_read_config_byte(dev, 0x43, &stat);
                }

                *old = new;
                (void) pci_write_config_dword(dev, 0x40, new);

                /*
                 * And let things settle...
                 */
                udelay(10);
        }

        local_irq_restore(flags);
}

static void ns87415_dev_select(ide_drive_t *drive)
{
        ns87415_prepare_drive(drive,
                              !!(drive->dev_flags & IDE_DFLAG_USING_DMA));

        outb(drive->select | ATA_DEVICE_OBS, drive->hwif->io_ports.device_addr);
}

static void ns87415_dma_start(ide_drive_t *drive)
{
        ns87415_prepare_drive(drive, 1);
        ide_dma_start(drive);
}

static int ns87415_dma_end(ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        u8 dma_stat = 0, dma_cmd = 0;

        dma_stat = hwif->dma_ops->dma_sff_read_status(hwif);
        /* get DMA command mode */
        dma_cmd = inb(hwif->dma_base + ATA_DMA_CMD);
        /* stop DMA */
        outb(dma_cmd & ~1, hwif->dma_base + ATA_DMA_CMD);
        /* from ERRATA: clear the INTR & ERROR bits */
        dma_cmd = inb(hwif->dma_base + ATA_DMA_CMD);
        outb(dma_cmd | 6, hwif->dma_base + ATA_DMA_CMD);

        ns87415_prepare_drive(drive, 0);

        /* verify good DMA status */
        return (dma_stat & 7) != 4;
}

static void init_hwif_ns87415 (ide_hwif_t *hwif)
{
        struct pci_dev *dev = to_pci_dev(hwif->dev);
        unsigned int ctrl, using_inta;
        u8 progif;
#ifdef __sparc_v9__
        int timeout;
        u8 stat;
#endif

        /*
         * We cannot probe for IRQ: both ports share common IRQ on INTA.
         * Also, leave IRQ masked during drive probing, to prevent infinite
         * interrupts from a potentially floating INTA..
         *
         * IRQs get unmasked in dev_select() when drive is first used.
         */
        (void) pci_read_config_dword(dev, 0x40, &ctrl);
        (void) pci_read_config_byte(dev, 0x09, &progif);
        /* is irq in "native" mode? */
        using_inta = progif & (1 << (hwif->channel << 1));
        if (!using_inta)
                using_inta = ctrl & (1 << (4 + hwif->channel));
        if (hwif->mate) {
                hwif->select_data = hwif->mate->select_data;
        } else {
                hwif->select_data = (unsigned long)
                                        &ns87415_control[ns87415_count++];
                ctrl |= (1 << 8) | (1 << 9);    /* mask both IRQs */
                if (using_inta)
                        ctrl &= ~(1 << 6);      /* unmask INTA */
                *((unsigned int *)hwif->select_data) = ctrl;
                (void) pci_write_config_dword(dev, 0x40, ctrl);

                /*
                 * Set prefetch size to 512 bytes for both ports,
                 * but don't turn on/off prefetching here.
                 */
                pci_write_config_byte(dev, 0x55, 0xee);

#ifdef __sparc_v9__
                /*
                 * XXX: Reset the device, if we don't it will not respond to
                 *      dev_select() properly during first ide_probe_port().
                 */
                timeout = 10000;
                outb(12, hwif->io_ports.ctl_addr);
                udelay(10);
                outb(8, hwif->io_ports.ctl_addr);
                do {
                        udelay(50);
                        stat = hwif->tp_ops->read_status(hwif);
                        if (stat == 0xff)
                                break;
                } while ((stat & ATA_BUSY) && --timeout);
#endif
        }

        if (!using_inta)
                hwif->irq = pci_get_legacy_ide_irq(dev, hwif->channel);

        if (!hwif->dma_base)
                return;

        outb(0x60, hwif->dma_base + ATA_DMA_STATUS);
}

static const struct ide_tp_ops ns87415_tp_ops = {
        .exec_command           = ide_exec_command,
        .read_status            = ide_read_status,
        .read_altstatus         = ide_read_altstatus,
        .write_devctl           = ide_write_devctl,

        .dev_select             = ns87415_dev_select,
        .tf_load                = ide_tf_load,
        .tf_read                = ide_tf_read,

        .input_data             = ide_input_data,
        .output_data            = ide_output_data,
};

static const struct ide_dma_ops ns87415_dma_ops = {
        .dma_host_set           = ide_dma_host_set,
        .dma_setup              = ide_dma_setup,
        .dma_start              = ns87415_dma_start,
        .dma_end                = ns87415_dma_end,
        .dma_test_irq           = ide_dma_test_irq,
        .dma_lost_irq           = ide_dma_lost_irq,
        .dma_timer_expiry       = ide_dma_sff_timer_expiry,
        .dma_sff_read_status    = superio_dma_sff_read_status,
};

static const struct ide_port_info ns87415_chipset = {
        .name           = DRV_NAME,
        .init_hwif      = init_hwif_ns87415,
        .tp_ops         = &ns87415_tp_ops,
        .dma_ops        = &ns87415_dma_ops,
        .host_flags     = IDE_HFLAG_TRUST_BIOS_FOR_DMA |
                          IDE_HFLAG_NO_ATAPI_DMA,
};

static int ns87415_init_one(struct pci_dev *dev, const struct pci_device_id *id)
{
        struct ide_port_info d = ns87415_chipset;

#ifdef CONFIG_SUPERIO
        if (PCI_SLOT(dev->devfn) == 0xE) {
                /* Built-in - assume it's under superio. */
                d.init_iops = superio_init_iops;
                d.tp_ops = &superio_tp_ops;
        }
#endif
        return ide_pci_init_one(dev, &d, NULL);
}

static const struct pci_device_id ns87415_pci_tbl[] = {
        { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_87415), 0 },
        { 0, },
};
MODULE_DEVICE_TABLE(pci, ns87415_pci_tbl);

static struct pci_driver ns87415_pci_driver = {
        .name           = "NS87415_IDE",
        .id_table       = ns87415_pci_tbl,
        .probe          = ns87415_init_one,
        .remove         = ide_pci_remove,
        .suspend        = ide_pci_suspend,
        .resume         = ide_pci_resume,
};

static int __init ns87415_ide_init(void)
{
        return ide_pci_register_driver(&ns87415_pci_driver);
}

static void __exit ns87415_ide_exit(void)
{
        pci_unregister_driver(&ns87415_pci_driver);
}

module_init(ns87415_ide_init);
module_exit(ns87415_ide_exit);

MODULE_AUTHOR("Mark Lord, Eddie Dost, Andre Hedrick");
MODULE_DESCRIPTION("PCI driver module for NS87415 IDE");
MODULE_LICENSE("GPL");