ide-xfer-mode.c

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#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/ide.h>
#include <linux/bitops.h>

static const char *udma_str[] =
     { "UDMA/16", "UDMA/25",  "UDMA/33",  "UDMA/44",
       "UDMA/66", "UDMA/100", "UDMA/133", "UDMA7" };
static const char *mwdma_str[] =
    { "MWDMA0", "MWDMA1", "MWDMA2", "MWDMA3", "MWDMA4" };
static const char *swdma_str[] =
    { "SWDMA0", "SWDMA1", "SWDMA2" };
static const char *pio_str[] =
    { "PIO0", "PIO1", "PIO2", "PIO3", "PIO4", "PIO5", "PIO6" };

const char *ide_xfer_verbose(u8 mode)
{
    const char *s;
    u8 i = mode & 0xf;

    if (mode >= XFER_UDMA_0 && mode <= XFER_UDMA_7)
        s = udma_str[i];
    else if (mode >= XFER_MW_DMA_0 && mode <= XFER_MW_DMA_4)
        s = mwdma_str[i];
    else if (mode >= XFER_SW_DMA_0 && mode <= XFER_SW_DMA_2)
        s = swdma_str[i];
    else if (mode >= XFER_PIO_0 && mode <= XFER_PIO_6)
        s = pio_str[i & 0x7];
    else if (mode == XFER_PIO_SLOW)
        s = "PIO SLOW";
    else
        s = "XFER ERROR";

    return s;
}
EXPORT_SYMBOL(ide_xfer_verbose);

static u8 ide_get_best_pio_mode(ide_drive_t *drive, u8 mode_wanted, u8 max_mode)
{
    u16 *id = drive->id;
    int pio_mode = -1, overridden = 0;

    if (mode_wanted != 255)
        return min_t(u8, mode_wanted, max_mode);

    if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_BLACKLIST) == 0)
        pio_mode = ide_scan_pio_blacklist((char *)&id[ATA_ID_PROD]);

    if (pio_mode != -1) {
        printk(KERN_INFO "%s: is on PIO blacklist\n", drive->name);
    } else {
        pio_mode = id[ATA_ID_OLD_PIO_MODES] >> 8;
        if (pio_mode > 2) { /* 2 is maximum allowed tPIO value */
            pio_mode = 2;
            overridden = 1;
        }

        if (id[ATA_ID_FIELD_VALID] & 2) {         /* ATA2? */
            if (ata_id_is_cfa(id) && (id[ATA_ID_CFA_MODES] & 7))
                pio_mode = 4 + min_t(int, 2,
                             id[ATA_ID_CFA_MODES] & 7);
            else if (ata_id_has_iordy(id)) {
                if (id[ATA_ID_PIO_MODES] & 7) {
                    overridden = 0;
                    if (id[ATA_ID_PIO_MODES] & 4)
                        pio_mode = 5;
                    else if (id[ATA_ID_PIO_MODES] & 2)
                        pio_mode = 4;
                    else
                        pio_mode = 3;
                }
            }
        }

        if (overridden)
            printk(KERN_INFO "%s: tPIO > 2, assuming tPIO = 2\n",
                     drive->name);
    }

    if (pio_mode > max_mode)
        pio_mode = max_mode;

    return pio_mode;
}

int ide_pio_need_iordy(ide_drive_t *drive, const u8 pio)
{
    /*
     * IORDY may lead to controller lock up on certain controllers
     * if the port is not occupied.
     */
    if (pio == 0 && (drive->hwif->port_flags & IDE_PFLAG_PROBING))
        return 0;
    return ata_id_pio_need_iordy(drive->id, pio);
}
EXPORT_SYMBOL_GPL(ide_pio_need_iordy);

int ide_set_pio_mode(ide_drive_t *drive, const u8 mode)
{
    ide_hwif_t *hwif = drive->hwif;
    const struct ide_port_ops *port_ops = hwif->port_ops;

    if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
        return 0;

    if (port_ops == NULL || port_ops->set_pio_mode == NULL)
        return -1;

    /*
     * TODO: temporary hack for some legacy host drivers that didn't
     * set transfer mode on the device in ->set_pio_mode method...
     */
    if (port_ops->set_dma_mode == NULL) {
        drive->pio_mode = mode;
        port_ops->set_pio_mode(hwif, drive);
        return 0;
    }

    if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
        if (ide_config_drive_speed(drive, mode))
            return -1;
        drive->pio_mode = mode;
        port_ops->set_pio_mode(hwif, drive);
        return 0;
    } else {
        drive->pio_mode = mode;
        port_ops->set_pio_mode(hwif, drive);
        return ide_config_drive_speed(drive, mode);
    }
}

int ide_set_dma_mode(ide_drive_t *drive, const u8 mode)
{
    ide_hwif_t *hwif = drive->hwif;
    const struct ide_port_ops *port_ops = hwif->port_ops;

    if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
        return 0;

    if (port_ops == NULL || port_ops->set_dma_mode == NULL)
        return -1;

    if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
        if (ide_config_drive_speed(drive, mode))
            return -1;
        drive->dma_mode = mode;
        port_ops->set_dma_mode(hwif, drive);
        return 0;
    } else {
        drive->dma_mode = mode;
        port_ops->set_dma_mode(hwif, drive);
        return ide_config_drive_speed(drive, mode);
    }
}
EXPORT_SYMBOL_GPL(ide_set_dma_mode);

/* req_pio == "255" for auto-tune */
void ide_set_pio(ide_drive_t *drive, u8 req_pio)
{
    ide_hwif_t *hwif = drive->hwif;
    const struct ide_port_ops *port_ops = hwif->port_ops;
    u8 host_pio, pio;

    if (port_ops == NULL || port_ops->set_pio_mode == NULL ||
        (hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
        return;

    BUG_ON(hwif->pio_mask == 0x00);

    host_pio = fls(hwif->pio_mask) - 1;

    pio = ide_get_best_pio_mode(drive, req_pio, host_pio);

    /*
     * TODO:
     * - report device max PIO mode
     * - check req_pio != 255 against device max PIO mode
     */
    printk(KERN_DEBUG "%s: host max PIO%d wanted PIO%d%s selected PIO%d\n",
              drive->name, host_pio, req_pio,
              req_pio == 255 ? "(auto-tune)" : "", pio);

    (void)ide_set_pio_mode(drive, XFER_PIO_0 + pio);
}
EXPORT_SYMBOL_GPL(ide_set_pio);

static u8 ide_rate_filter(ide_drive_t *drive, u8 speed)
{
    ide_hwif_t *hwif = drive->hwif;
    u8 mode = ide_find_dma_mode(drive, speed);

    if (mode == 0) {
        if (hwif->pio_mask)
            mode = fls(hwif->pio_mask) - 1 + XFER_PIO_0;
        else
            mode = XFER_PIO_4;
    }

/*  printk("%s: mode 0x%02x, speed 0x%02x\n", __func__, mode, speed); */

    return min(speed, mode);
}

int ide_set_xfer_rate(ide_drive_t *drive, u8 rate)
{
    ide_hwif_t *hwif = drive->hwif;
    const struct ide_port_ops *port_ops = hwif->port_ops;

    if (port_ops == NULL || port_ops->set_dma_mode == NULL ||
        (hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
        return -1;

    rate = ide_rate_filter(drive, rate);

    BUG_ON(rate < XFER_PIO_0);

    if (rate >= XFER_PIO_0 && rate <= XFER_PIO_6)
        return ide_set_pio_mode(drive, rate);

    return ide_set_dma_mode(drive, rate);
}