pata_cmd640.c

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/*
 * pata_cmd640.c    - CMD640 PCI PATA for new ATA layer
 *            (C) 2007 Red Hat Inc
 *
 * Based upon
 *  linux/drivers/ide/pci/cmd640.c      Version 1.02  Sep 01, 1996
 *
 *  Copyright (C) 1995-1996  Linus Torvalds & authors (see driver)
 *
 *  This drives only the PCI version of the controller. If you have a
 *  VLB one then we have enough docs to support it but you can write
 *  your own code.
 */

#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 <linux/gfp.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>

#define DRV_NAME "pata_cmd640"
#define DRV_VERSION "0.0.5"

struct cmd640_reg {
    int last;
    u8 reg58[ATA_MAX_DEVICES];
};

enum {
    CFR = 0x50,
    CNTRL = 0x51,
    CMDTIM = 0x52,
    ARTIM0 = 0x53,
    DRWTIM0 = 0x54,
    ARTIM23 = 0x57,
    DRWTIM23 = 0x58,
    BRST = 0x59
};

static void cmd640_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
    struct cmd640_reg *timing = ap->private_data;
    struct pci_dev *pdev = to_pci_dev(ap->host->dev);
    struct ata_timing t;
    const unsigned long T = 1000000 / 33;
    const u8 setup_data[] = { 0x40, 0x40, 0x40, 0x80, 0x00 };
    u8 reg;
    int arttim = ARTIM0 + 2 * adev->devno;
    struct ata_device *pair = ata_dev_pair(adev);

    if (ata_timing_compute(adev, adev->pio_mode, &t, T, 0) < 0) {
        printk(KERN_ERR DRV_NAME ": mode computation failed.\n");
        return;
    }

    /* The second channel has shared timings and the setup timing is
       messy to switch to merge it for worst case */
    if (ap->port_no && pair) {
        struct ata_timing p;
        ata_timing_compute(pair, pair->pio_mode, &p, T, 1);
        ata_timing_merge(&p, &t, &t, ATA_TIMING_SETUP);
    }

    /* Make the timings fit */
    if (t.recover > 16) {
        t.active += t.recover - 16;
        t.recover = 16;
    }
    if (t.active > 16)
        t.active = 16;

    /* Now convert the clocks into values we can actually stuff into
       the chip */

    if (t.recover > 1)
        t.recover--;    /* 640B only */
    else
        t.recover = 15;

    if (t.setup > 4)
        t.setup = 0xC0;
    else
        t.setup = setup_data[t.setup];

    if (ap->port_no == 0) {
        t.active &= 0x0F;   /* 0 = 16 */

        /* Load setup timing */
        pci_read_config_byte(pdev, arttim, &reg);
        reg &= 0x3F;
        reg |= t.setup;
        pci_write_config_byte(pdev, arttim, reg);

        /* Load active/recovery */
        pci_write_config_byte(pdev, arttim + 1, (t.active << 4) | t.recover);
    } else {
        /* Save the shared timings for channel, they will be loaded
           by qc_issue. Reloading the setup time is expensive so we
           keep a merged one loaded */
        pci_read_config_byte(pdev, ARTIM23, &reg);
        reg &= 0x3F;
        reg |= t.setup;
        pci_write_config_byte(pdev, ARTIM23, reg);
        timing->reg58[adev->devno] = (t.active << 4) | t.recover;
    }
}


static unsigned int cmd640_qc_issue(struct ata_queued_cmd *qc)
{
    struct ata_port *ap = qc->ap;
    struct ata_device *adev = qc->dev;
    struct pci_dev *pdev = to_pci_dev(ap->host->dev);
    struct cmd640_reg *timing = ap->private_data;

    if (ap->port_no != 0 && adev->devno != timing->last) {
        pci_write_config_byte(pdev, DRWTIM23, timing->reg58[adev->devno]);
        timing->last = adev->devno;
    }
    return ata_sff_qc_issue(qc);
}

static int cmd640_port_start(struct ata_port *ap)
{
    struct pci_dev *pdev = to_pci_dev(ap->host->dev);
    struct cmd640_reg *timing;

    timing = devm_kzalloc(&pdev->dev, sizeof(struct cmd640_reg), GFP_KERNEL);
    if (timing == NULL)
        return -ENOMEM;
    timing->last = -1;  /* Force a load */
    ap->private_data = timing;
    return 0;
}

static bool cmd640_sff_irq_check(struct ata_port *ap)
{
    struct pci_dev *pdev    = to_pci_dev(ap->host->dev);
    int irq_reg     = ap->port_no ? ARTIM23 : CFR;
    u8  irq_stat, irq_mask  = ap->port_no ? 0x10 : 0x04;

    pci_read_config_byte(pdev, irq_reg, &irq_stat);

    return irq_stat & irq_mask;
}

static struct scsi_host_template cmd640_sht = {
    ATA_PIO_SHT(DRV_NAME),
};

static struct ata_port_operations cmd640_port_ops = {
    .inherits   = &ata_sff_port_ops,
    /* In theory xfer_noirq is not needed once we kill the prefetcher */
    .sff_data_xfer  = ata_sff_data_xfer_noirq,
    .sff_irq_check  = cmd640_sff_irq_check,
    .qc_issue   = cmd640_qc_issue,
    .cable_detect   = ata_cable_40wire,
    .set_piomode    = cmd640_set_piomode,
    .port_start = cmd640_port_start,
};

static void cmd640_hardware_init(struct pci_dev *pdev)
{
    u8 ctrl;

    /* CMD640 detected, commiserations */
    pci_write_config_byte(pdev, 0x5B, 0x00);
    /* PIO0 command cycles */
    pci_write_config_byte(pdev, CMDTIM, 0);
    /* 512 byte bursts (sector) */
    pci_write_config_byte(pdev, BRST, 0x40);
    /*
     * A reporter a long time ago
     * Had problems with the data fifo
     * So don't run the risk
     * Of putting crap on the disk
     * For its better just to go slow
     */
    /* Do channel 0 */
    pci_read_config_byte(pdev, CNTRL, &ctrl);
    pci_write_config_byte(pdev, CNTRL, ctrl | 0xC0);
    /* Ditto for channel 1 */
    pci_read_config_byte(pdev, ARTIM23, &ctrl);
    ctrl |= 0x0C;
    pci_write_config_byte(pdev, ARTIM23, ctrl);
}

static int cmd640_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
{
    static const struct ata_port_info info = {
        .flags = ATA_FLAG_SLAVE_POSS,
        .pio_mask = ATA_PIO4,
        .port_ops = &cmd640_port_ops
    };
    const struct ata_port_info *ppi[] = { &info, NULL };
    int rc;

    rc = pcim_enable_device(pdev);
    if (rc)
        return rc;

    cmd640_hardware_init(pdev);

    return ata_pci_sff_init_one(pdev, ppi, &cmd640_sht, NULL, 0);
}

#ifdef CONFIG_PM
static int cmd640_reinit_one(struct pci_dev *pdev)
{
    struct ata_host *host = dev_get_drvdata(&pdev->dev);
    int rc;

    rc = ata_pci_device_do_resume(pdev);
    if (rc)
        return rc;
    cmd640_hardware_init(pdev);
    ata_host_resume(host);
    return 0;
}
#endif

static const struct pci_device_id cmd640[] = {
    { PCI_VDEVICE(CMD, 0x640), 0 },
    { },
};

static struct pci_driver cmd640_pci_driver = {
    .name       = DRV_NAME,
    .id_table   = cmd640,
    .probe      = cmd640_init_one,
    .remove     = ata_pci_remove_one,
#ifdef CONFIG_PM
    .suspend    = ata_pci_device_suspend,
    .resume     = cmd640_reinit_one,
#endif
};

module_pci_driver(cmd640_pci_driver);

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for CMD640 PATA controllers");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, cmd640);
MODULE_VERSION(DRV_VERSION);