tc86c001.c

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/*
 * Copyright (C) 2002 Toshiba Corporation
 * Copyright (C) 2005-2006 MontaVista Software, Inc. <[email protected]>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/types.h>
#include <linux/pci.h>
#include <linux/ide.h>
#include <linux/module.h>

#define DRV_NAME "tc86c001"

static void tc86c001_set_mode(ide_hwif_t *hwif, ide_drive_t *drive)
{
    unsigned long scr_port  = hwif->config_data + (drive->dn ? 0x02 : 0x00);
    u16 mode, scr       = inw(scr_port);
    const u8 speed      = drive->dma_mode;

    switch (speed) {
    case XFER_UDMA_4:   mode = 0x00c0; break;
    case XFER_UDMA_3:   mode = 0x00b0; break;
    case XFER_UDMA_2:   mode = 0x00a0; break;
    case XFER_UDMA_1:   mode = 0x0090; break;
    case XFER_UDMA_0:   mode = 0x0080; break;
    case XFER_MW_DMA_2: mode = 0x0070; break;
    case XFER_MW_DMA_1: mode = 0x0060; break;
    case XFER_MW_DMA_0: mode = 0x0050; break;
    case XFER_PIO_4:    mode = 0x0400; break;
    case XFER_PIO_3:    mode = 0x0300; break;
    case XFER_PIO_2:    mode = 0x0200; break;
    case XFER_PIO_1:    mode = 0x0100; break;
    case XFER_PIO_0:
    default:        mode = 0x0000; break;
    }

    scr &= (speed < XFER_MW_DMA_0) ? 0xf8ff : 0xff0f;
    scr |= mode;
    outw(scr, scr_port);
}

static void tc86c001_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)
{
    drive->dma_mode = drive->pio_mode;
    tc86c001_set_mode(hwif, drive);
}

/*
 * HACKITY HACK
 *
 * This is a workaround for the limitation 5 of the TC86C001 IDE controller:
 * if a DMA transfer terminates prematurely, the controller leaves the device's
 * interrupt request (INTRQ) pending and does not generate a PCI interrupt (or
 * set the interrupt bit in the DMA status register), thus no PCI interrupt
 * will occur until a DMA transfer has been successfully completed.
 *
 * We work around this by initiating dummy, zero-length DMA transfer on
 * a DMA timeout expiration. I found no better way to do this with the current
 * IDE core than to temporarily replace a higher level driver's timer expiry
 * handler with our own backing up to that handler in case our recovery fails.
 */
static int tc86c001_timer_expiry(ide_drive_t *drive)
{
    ide_hwif_t *hwif    = drive->hwif;
    ide_expiry_t *expiry    = ide_get_hwifdata(hwif);
    u8 dma_stat     = inb(hwif->dma_base + ATA_DMA_STATUS);

    /* Restore a higher level driver's expiry handler first. */
    hwif->expiry = expiry;

    if ((dma_stat & 5) == 1) {  /* DMA active and no interrupt */
        unsigned long sc_base   = hwif->config_data;
        unsigned long twcr_port = sc_base + (drive->dn ? 0x06 : 0x04);
        u8 dma_cmd      = inb(hwif->dma_base + ATA_DMA_CMD);

        printk(KERN_WARNING "%s: DMA interrupt possibly stuck, "
               "attempting recovery...\n", drive->name);

        /* Stop DMA */
        outb(dma_cmd & ~0x01, hwif->dma_base + ATA_DMA_CMD);

        /* Setup the dummy DMA transfer */
        outw(0, sc_base + 0x0a);    /* Sector Count */
        outw(0, twcr_port); /* Transfer Word Count 1 or 2 */

        /* Start the dummy DMA transfer */

        /* clear R_OR_WCTR for write */
        outb(0x00, hwif->dma_base + ATA_DMA_CMD);
        /* set START_STOPBM */
        outb(0x01, hwif->dma_base + ATA_DMA_CMD);

        /*
         * If an interrupt was pending, it should come thru shortly.
         * If not, a higher level driver's expiry handler should
         * eventually cause some kind of recovery from the DMA stall.
         */
        return WAIT_MIN_SLEEP;
    }

    /* Chain to the restored expiry handler if DMA wasn't active. */
    if (likely(expiry != NULL))
        return expiry(drive);

    /* If there was no handler, "emulate" that for ide_timer_expiry()... */
    return -1;
}

static void tc86c001_dma_start(ide_drive_t *drive)
{
    ide_hwif_t *hwif    = drive->hwif;
    unsigned long sc_base   = hwif->config_data;
    unsigned long twcr_port = sc_base + (drive->dn ? 0x06 : 0x04);
    unsigned long nsectors  = blk_rq_sectors(hwif->rq);

    /*
     * We have to manually load the sector count and size into
     * the appropriate system control registers for DMA to work
     * with LBA48 and ATAPI devices...
     */
    outw(nsectors, sc_base + 0x0a); /* Sector Count */
    outw(SECTOR_SIZE / 2, twcr_port); /* Transfer Word Count 1/2 */

    /* Install our timeout expiry hook, saving the current handler... */
    ide_set_hwifdata(hwif, hwif->expiry);
    hwif->expiry = &tc86c001_timer_expiry;

    ide_dma_start(drive);
}

static u8 tc86c001_cable_detect(ide_hwif_t *hwif)
{
    struct pci_dev *dev = to_pci_dev(hwif->dev);
    unsigned long sc_base = pci_resource_start(dev, 5);
    u16 scr1 = inw(sc_base + 0x00);

    /*
     * System Control  1 Register bit 13 (PDIAGN):
     * 0=80-pin cable, 1=40-pin cable
     */
    return (scr1 & 0x2000) ? ATA_CBL_PATA40 : ATA_CBL_PATA80;
}

static void __devinit init_hwif_tc86c001(ide_hwif_t *hwif)
{
    struct pci_dev *dev = to_pci_dev(hwif->dev);
    unsigned long sc_base   = pci_resource_start(dev, 5);
    u16 scr1        = inw(sc_base + 0x00);

    /* System Control 1 Register bit 15 (Soft Reset) set */
    outw(scr1 |  0x8000, sc_base + 0x00);

    /* System Control 1 Register bit 14 (FIFO Reset) set */
    outw(scr1 |  0x4000, sc_base + 0x00);

    /* System Control 1 Register: reset clear */
    outw(scr1 & ~0xc000, sc_base + 0x00);

    /* Store the system control register base for convenience... */
    hwif->config_data = sc_base;

    if (!hwif->dma_base)
        return;

    /*
     * Sector Count Control Register bits 0 and 1 set:
     * software sets Sector Count Register for master and slave device
     */
    outw(0x0003, sc_base + 0x0c);

    /* Sector Count Register limit */
    hwif->rqsize     = 0xffff;
}

static const struct ide_port_ops tc86c001_port_ops = {
    .set_pio_mode       = tc86c001_set_pio_mode,
    .set_dma_mode       = tc86c001_set_mode,
    .cable_detect       = tc86c001_cable_detect,
};

static const struct ide_dma_ops tc86c001_dma_ops = {
    .dma_host_set       = ide_dma_host_set,
    .dma_setup      = ide_dma_setup,
    .dma_start      = tc86c001_dma_start,
    .dma_end        = ide_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    = ide_dma_sff_read_status,
};

static const struct ide_port_info tc86c001_chipset __devinitconst = {
    .name       = DRV_NAME,
    .init_hwif  = init_hwif_tc86c001,
    .port_ops   = &tc86c001_port_ops,
    .dma_ops    = &tc86c001_dma_ops,
    .host_flags = IDE_HFLAG_SINGLE | IDE_HFLAG_OFF_BOARD,
    .pio_mask   = ATA_PIO4,
    .mwdma_mask = ATA_MWDMA2,
    .udma_mask  = ATA_UDMA4,
};

static int __devinit tc86c001_init_one(struct pci_dev *dev,
                       const struct pci_device_id *id)
{
    int rc;

    rc = pci_enable_device(dev);
    if (rc)
        goto out;

    rc = pci_request_region(dev, 5, DRV_NAME);
    if (rc) {
        printk(KERN_ERR DRV_NAME ": system control regs already in use");
        goto out_disable;
    }

    rc = ide_pci_init_one(dev, &tc86c001_chipset, NULL);
    if (rc)
        goto out_release;

    goto out;

out_release:
    pci_release_region(dev, 5);
out_disable:
    pci_disable_device(dev);
out:
    return rc;
}

static void __devexit tc86c001_remove(struct pci_dev *dev)
{
    ide_pci_remove(dev);
    pci_release_region(dev, 5);
    pci_disable_device(dev);
}

static const struct pci_device_id tc86c001_pci_tbl[] = {
    { PCI_VDEVICE(TOSHIBA_2, PCI_DEVICE_ID_TOSHIBA_TC86C001_IDE), 0 },
    { 0, }
};
MODULE_DEVICE_TABLE(pci, tc86c001_pci_tbl);

static struct pci_driver tc86c001_pci_driver = {
    .name       = "TC86C001",
    .id_table   = tc86c001_pci_tbl,
    .probe      = tc86c001_init_one,
    .remove     = __devexit_p(tc86c001_remove),
};

static int __init tc86c001_ide_init(void)
{
    return ide_pci_register_driver(&tc86c001_pci_driver);
}

static void __exit tc86c001_ide_exit(void)
{
    pci_unregister_driver(&tc86c001_pci_driver);
}

module_init(tc86c001_ide_init);
module_exit(tc86c001_ide_exit);

MODULE_AUTHOR("MontaVista Software, Inc. <[email protected]>");
MODULE_DESCRIPTION("PCI driver module for TC86C001 IDE");
MODULE_LICENSE("GPL");