pata_ixp4xx_cf.c

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/*
 * ixp4xx PATA/Compact Flash driver
 * Copyright (C) 2006-07 Tower Technologies
 * Author: Alessandro Zummo <[email protected]>
 *
 * An ATA driver to handle a Compact Flash connected
 * to the ixp4xx expansion bus in TrueIDE mode. The CF
 * must have it chip selects connected to two CS lines
 * on the ixp4xx. In the irq is not available, you might
 * want to modify both this driver and libata to run in
 * polling mode.
 *
 * 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.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/libata.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <scsi/scsi_host.h>

#define DRV_NAME    "pata_ixp4xx_cf"
#define DRV_VERSION "0.2"

static int ixp4xx_set_mode(struct ata_link *link, struct ata_device **error)
{
    struct ata_device *dev;

    ata_for_each_dev(dev, link, ENABLED) {
        ata_dev_info(dev, "configured for PIO0\n");
        dev->pio_mode = XFER_PIO_0;
        dev->xfer_mode = XFER_PIO_0;
        dev->xfer_shift = ATA_SHIFT_PIO;
        dev->flags |= ATA_DFLAG_PIO;
    }
    return 0;
}

static unsigned int ixp4xx_mmio_data_xfer(struct ata_device *dev,
                unsigned char *buf, unsigned int buflen, int rw)
{
    unsigned int i;
    unsigned int words = buflen >> 1;
    u16 *buf16 = (u16 *) buf;
    struct ata_port *ap = dev->link->ap;
    void __iomem *mmio = ap->ioaddr.data_addr;
    struct ixp4xx_pata_data *data = ap->host->dev->platform_data;

    /* set the expansion bus in 16bit mode and restore
     * 8 bit mode after the transaction.
     */
    *data->cs0_cfg &= ~(0x01);
    udelay(100);

    /* Transfer multiple of 2 bytes */
    if (rw == READ)
        for (i = 0; i < words; i++)
            buf16[i] = readw(mmio);
    else
        for (i = 0; i < words; i++)
            writew(buf16[i], mmio);

    /* Transfer trailing 1 byte, if any. */
    if (unlikely(buflen & 0x01)) {
        u16 align_buf[1] = { 0 };
        unsigned char *trailing_buf = buf + buflen - 1;

        if (rw == READ) {
            align_buf[0] = readw(mmio);
            memcpy(trailing_buf, align_buf, 1);
        } else {
            memcpy(align_buf, trailing_buf, 1);
            writew(align_buf[0], mmio);
        }
        words++;
    }

    udelay(100);
    *data->cs0_cfg |= 0x01;

    return words << 1;
}

static struct scsi_host_template ixp4xx_sht = {
    ATA_PIO_SHT(DRV_NAME),
};

static struct ata_port_operations ixp4xx_port_ops = {
    .inherits       = &ata_sff_port_ops,
    .sff_data_xfer      = ixp4xx_mmio_data_xfer,
    .cable_detect       = ata_cable_40wire,
    .set_mode       = ixp4xx_set_mode,
};

static void ixp4xx_setup_port(struct ata_port *ap,
                  struct ixp4xx_pata_data *data,
                  unsigned long raw_cs0, unsigned long raw_cs1)
{
    struct ata_ioports *ioaddr = &ap->ioaddr;
    unsigned long raw_cmd = raw_cs0;
    unsigned long raw_ctl = raw_cs1 + 0x06;

    ioaddr->cmd_addr    = data->cs0;
    ioaddr->altstatus_addr  = data->cs1 + 0x06;
    ioaddr->ctl_addr    = data->cs1 + 0x06;

    ata_sff_std_ports(ioaddr);

#ifndef __ARMEB__

    /* adjust the addresses to handle the address swizzling of the
     * ixp4xx in little endian mode.
     */

    *(unsigned long *)&ioaddr->data_addr        ^= 0x02;
    *(unsigned long *)&ioaddr->cmd_addr     ^= 0x03;
    *(unsigned long *)&ioaddr->altstatus_addr   ^= 0x03;
    *(unsigned long *)&ioaddr->ctl_addr     ^= 0x03;
    *(unsigned long *)&ioaddr->error_addr       ^= 0x03;
    *(unsigned long *)&ioaddr->feature_addr     ^= 0x03;
    *(unsigned long *)&ioaddr->nsect_addr       ^= 0x03;
    *(unsigned long *)&ioaddr->lbal_addr        ^= 0x03;
    *(unsigned long *)&ioaddr->lbam_addr        ^= 0x03;
    *(unsigned long *)&ioaddr->lbah_addr        ^= 0x03;
    *(unsigned long *)&ioaddr->device_addr      ^= 0x03;
    *(unsigned long *)&ioaddr->status_addr      ^= 0x03;
    *(unsigned long *)&ioaddr->command_addr     ^= 0x03;

    raw_cmd ^= 0x03;
    raw_ctl ^= 0x03;
#endif

    ata_port_desc(ap, "cmd 0x%lx ctl 0x%lx", raw_cmd, raw_ctl);
}

static __devinit int ixp4xx_pata_probe(struct platform_device *pdev)
{
    unsigned int irq;
    struct resource *cs0, *cs1;
    struct ata_host *host;
    struct ata_port *ap;
    struct ixp4xx_pata_data *data = pdev->dev.platform_data;

    cs0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    cs1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);

    if (!cs0 || !cs1)
        return -EINVAL;

    /* allocate host */
    host = ata_host_alloc(&pdev->dev, 1);
    if (!host)
        return -ENOMEM;

    /* acquire resources and fill host */
    pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);

    data->cs0 = devm_ioremap(&pdev->dev, cs0->start, 0x1000);
    data->cs1 = devm_ioremap(&pdev->dev, cs1->start, 0x1000);

    if (!data->cs0 || !data->cs1)
        return -ENOMEM;

    irq = platform_get_irq(pdev, 0);
    if (irq)
        irq_set_irq_type(irq, IRQ_TYPE_EDGE_RISING);

    /* Setup expansion bus chip selects */
    *data->cs0_cfg = data->cs0_bits;
    *data->cs1_cfg = data->cs1_bits;

    ap = host->ports[0];

    ap->ops = &ixp4xx_port_ops;
    ap->pio_mask = ATA_PIO4;
    ap->flags |= ATA_FLAG_NO_ATAPI;

    ixp4xx_setup_port(ap, data, cs0->start, cs1->start);

    ata_print_version_once(&pdev->dev, DRV_VERSION);

    /* activate host */
    return ata_host_activate(host, irq, ata_sff_interrupt, 0, &ixp4xx_sht);
}

static __devexit int ixp4xx_pata_remove(struct platform_device *dev)
{
    struct ata_host *host = platform_get_drvdata(dev);

    ata_host_detach(host);

    return 0;
}

static struct platform_driver ixp4xx_pata_platform_driver = {
    .driver  = {
        .name   = DRV_NAME,
        .owner  = THIS_MODULE,
    },
    .probe      = ixp4xx_pata_probe,
    .remove     = __devexit_p(ixp4xx_pata_remove),
};

module_platform_driver(ixp4xx_pata_platform_driver);

MODULE_AUTHOR("Alessandro Zummo <[email protected]>");
MODULE_DESCRIPTION("low-level driver for ixp4xx Compact Flash PATA");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
MODULE_ALIAS("platform:" DRV_NAME);