pata_sc1200.c

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/*
 * New ATA layer SC1200 driver      Alan Cox <[email protected]>
 *
 * TODO: Mode selection filtering
 * TODO: Needs custom DMA cleanup code
 *
 * Based very heavily on
 *
 * linux/drivers/ide/pci/sc1200.c       Version 0.91    28-Jan-2003
 *
 * Copyright (C) 2000-2002      Mark Lord <[email protected]>
 * May be copied or modified under the terms of the GNU General Public License
 *
 * Development of this chipset driver was funded
 * by the nice folks at National Semiconductor.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

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

#define DRV_NAME    "pata_sc1200"
#define DRV_VERSION "0.2.6"

#define SC1200_REV_A    0x00
#define SC1200_REV_B1   0x01
#define SC1200_REV_B3   0x02
#define SC1200_REV_C1   0x03
#define SC1200_REV_D1   0x04

static int sc1200_clock(void)
{
    /* Magic registers that give us the chipset data */
    u8 chip_id = inb(0x903C);
    u8 silicon_rev = inb(0x903D);
    u16 pci_clock;

    if (chip_id == 0x04 && silicon_rev < SC1200_REV_B1)
        return 0;   /* 33 MHz mode */

    /* Clock generator configuration 0x901E its 8/9 are the PCI clocking
       0/3 is 33Mhz 1 is 48 2 is 66 */

    pci_clock = inw(0x901E);
    pci_clock >>= 8;
    pci_clock &= 0x03;
    if (pci_clock == 3)
        pci_clock = 0;
    return pci_clock;
}

static void sc1200_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
    static const u32 pio_timings[4][5] = {
        /* format0, 33Mhz */
        { 0x00009172, 0x00012171, 0x00020080, 0x00032010, 0x00040010 },
        /* format1, 33Mhz */
        { 0xd1329172, 0x71212171, 0x30200080, 0x20102010, 0x00100010 },
        /* format1, 48Mhz */
        { 0xfaa3f4f3, 0xc23232b2, 0x513101c1, 0x31213121, 0x10211021 },
        /* format1, 66Mhz */
        { 0xfff4fff4, 0xf35353d3, 0x814102f1, 0x42314231, 0x11311131 }
    };

    struct pci_dev *pdev = to_pci_dev(ap->host->dev);
    u32 format;
    unsigned int reg = 0x40 + 0x10 * ap->port_no;
    int mode = adev->pio_mode - XFER_PIO_0;

    pci_read_config_dword(pdev, reg + 4, &format);
    format >>= 31;
    format += sc1200_clock();
    pci_write_config_dword(pdev, reg + 8 * adev->devno,
                pio_timings[format][mode]);
}

static void sc1200_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
    static const u32 udma_timing[3][3] = {
        { 0x00921250, 0x00911140, 0x00911030 },
        { 0x00932470, 0x00922260, 0x00922140 },
        { 0x009436A1, 0x00933481, 0x00923261 }
    };

    static const u32 mwdma_timing[3][3] = {
        { 0x00077771, 0x00012121, 0x00002020 },
        { 0x000BBBB2, 0x00024241, 0x00013131 },
        { 0x000FFFF3, 0x00035352, 0x00015151 }
    };

    int clock = sc1200_clock();
    struct pci_dev *pdev = to_pci_dev(ap->host->dev);
    unsigned int reg = 0x40 + 0x10 * ap->port_no;
    int mode = adev->dma_mode;
    u32 format;

    if (mode >= XFER_UDMA_0)
        format = udma_timing[clock][mode - XFER_UDMA_0];
    else
        format = mwdma_timing[clock][mode - XFER_MW_DMA_0];

    if (adev->devno == 0) {
        u32 timings;

        pci_read_config_dword(pdev, reg + 4, &timings);
        timings &= 0x80000000UL;
        timings |= format;
        pci_write_config_dword(pdev, reg + 4, timings);
    } else
        pci_write_config_dword(pdev, reg + 12, format);
}

static unsigned int sc1200_qc_issue(struct ata_queued_cmd *qc)
{
    struct ata_port *ap = qc->ap;
    struct ata_device *adev = qc->dev;
    struct ata_device *prev = ap->private_data;

    /* See if the DMA settings could be wrong */
    if (ata_dma_enabled(adev) && adev != prev && prev != NULL) {
        /* Maybe, but do the channels match MWDMA/UDMA ? */
        if ((ata_using_udma(adev) && !ata_using_udma(prev)) ||
            (ata_using_udma(prev) && !ata_using_udma(adev)))
                /* Switch the mode bits */
                sc1200_set_dmamode(ap, adev);
    }

    return ata_bmdma_qc_issue(qc);
}

static int sc1200_qc_defer(struct ata_queued_cmd *qc)
{
    struct ata_host *host = qc->ap->host;
    struct ata_port *alt = host->ports[1 ^ qc->ap->port_no];
    int rc;

    /* First apply the usual rules */
    rc = ata_std_qc_defer(qc);
    if (rc != 0)
        return rc;

    /* Now apply serialization rules. Only allow a command if the
       other channel state machine is idle */
    if (alt && alt->qc_active)
        return  ATA_DEFER_PORT;
    return 0;
}

static struct scsi_host_template sc1200_sht = {
    ATA_BMDMA_SHT(DRV_NAME),
    .sg_tablesize   = LIBATA_DUMB_MAX_PRD,
};

static struct ata_port_operations sc1200_port_ops = {
    .inherits   = &ata_bmdma_port_ops,
    .qc_prep    = ata_bmdma_dumb_qc_prep,
    .qc_issue   = sc1200_qc_issue,
    .qc_defer   = sc1200_qc_defer,
    .cable_detect   = ata_cable_40wire,
    .set_piomode    = sc1200_set_piomode,
    .set_dmamode    = sc1200_set_dmamode,
};

static int sc1200_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_PIO4,
        .mwdma_mask = ATA_MWDMA2,
        .udma_mask = ATA_UDMA2,
        .port_ops = &sc1200_port_ops
    };
    const struct ata_port_info *ppi[] = { &info, NULL };

    return ata_pci_bmdma_init_one(dev, ppi, &sc1200_sht, NULL, 0);
}

static const struct pci_device_id sc1200[] = {
    { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_SCx200_IDE), },

    { },
};

static struct pci_driver sc1200_pci_driver = {
    .name       = DRV_NAME,
    .id_table   = sc1200,
    .probe      = sc1200_init_one,
    .remove     = ata_pci_remove_one,
#ifdef CONFIG_PM
    .suspend    = ata_pci_device_suspend,
    .resume     = ata_pci_device_resume,
#endif
};

module_pci_driver(sc1200_pci_driver);

MODULE_AUTHOR("Alan Cox, Mark Lord");
MODULE_DESCRIPTION("low-level driver for the NS/AMD SC1200");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, sc1200);
MODULE_VERSION(DRV_VERSION);