a3000.c

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#include <linux/types.h>
#include <linux/mm.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/module.h>

#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/amigaints.h>
#include <asm/amigahw.h>

#include "scsi.h"
#include "wd33c93.h"
#include "a3000.h"


struct a3000_hostdata {
    struct WD33C93_hostdata wh;
    struct a3000_scsiregs *regs;
};

static irqreturn_t a3000_intr(int irq, void *data)
{
    struct Scsi_Host *instance = data;
    struct a3000_hostdata *hdata = shost_priv(instance);
    unsigned int status = hdata->regs->ISTR;
    unsigned long flags;

    if (!(status & ISTR_INT_P))
        return IRQ_NONE;
    if (status & ISTR_INTS) {
        spin_lock_irqsave(instance->host_lock, flags);
        wd33c93_intr(instance);
        spin_unlock_irqrestore(instance->host_lock, flags);
        return IRQ_HANDLED;
    }
    pr_warning("Non-serviced A3000 SCSI-interrupt? ISTR = %02x\n", status);
    return IRQ_NONE;
}

static int dma_setup(struct scsi_cmnd *cmd, int dir_in)
{
    struct Scsi_Host *instance = cmd->device->host;
    struct a3000_hostdata *hdata = shost_priv(instance);
    struct WD33C93_hostdata *wh = &hdata->wh;
    struct a3000_scsiregs *regs = hdata->regs;
    unsigned short cntr = CNTR_PDMD | CNTR_INTEN;
    unsigned long addr = virt_to_bus(cmd->SCp.ptr);

    /*
     * if the physical address has the wrong alignment, or if
     * physical address is bad, or if it is a write and at the
     * end of a physical memory chunk, then allocate a bounce
     * buffer
     */
    if (addr & A3000_XFER_MASK) {
        wh->dma_bounce_len = (cmd->SCp.this_residual + 511) & ~0x1ff;
        wh->dma_bounce_buffer = kmalloc(wh->dma_bounce_len,
                        GFP_KERNEL);

        /* can't allocate memory; use PIO */
        if (!wh->dma_bounce_buffer) {
            wh->dma_bounce_len = 0;
            return 1;
        }

        if (!dir_in) {
            /* copy to bounce buffer for a write */
            memcpy(wh->dma_bounce_buffer, cmd->SCp.ptr,
                   cmd->SCp.this_residual);
        }

        addr = virt_to_bus(wh->dma_bounce_buffer);
    }

    /* setup dma direction */
    if (!dir_in)
        cntr |= CNTR_DDIR;

    /* remember direction */
    wh->dma_dir = dir_in;

    regs->CNTR = cntr;

    /* setup DMA *physical* address */
    regs->ACR = addr;

    if (dir_in) {
        /* invalidate any cache */
        cache_clear(addr, cmd->SCp.this_residual);
    } else {
        /* push any dirty cache */
        cache_push(addr, cmd->SCp.this_residual);
    }

    /* start DMA */
    mb();           /* make sure setup is completed */
    regs->ST_DMA = 1;
    mb();           /* make sure DMA has started before next IO */

    /* return success */
    return 0;
}

static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
             int status)
{
    struct a3000_hostdata *hdata = shost_priv(instance);
    struct WD33C93_hostdata *wh = &hdata->wh;
    struct a3000_scsiregs *regs = hdata->regs;

    /* disable SCSI interrupts */
    unsigned short cntr = CNTR_PDMD;

    if (!wh->dma_dir)
        cntr |= CNTR_DDIR;

    regs->CNTR = cntr;
    mb();           /* make sure CNTR is updated before next IO */

    /* flush if we were reading */
    if (wh->dma_dir) {
        regs->FLUSH = 1;
        mb();       /* don't allow prefetch */
        while (!(regs->ISTR & ISTR_FE_FLG))
            barrier();
        mb();       /* no IO until FLUSH is done */
    }

    /* clear a possible interrupt */
    /* I think that this CINT is only necessary if you are
     * using the terminal count features.   HM 7 Mar 1994
     */
    regs->CINT = 1;

    /* stop DMA */
    regs->SP_DMA = 1;
    mb();           /* make sure DMA is stopped before next IO */

    /* restore the CONTROL bits (minus the direction flag) */
    regs->CNTR = CNTR_PDMD | CNTR_INTEN;
    mb();           /* make sure CNTR is updated before next IO */

    /* copy from a bounce buffer, if necessary */
    if (status && wh->dma_bounce_buffer) {
        if (SCpnt) {
            if (wh->dma_dir && SCpnt)
                memcpy(SCpnt->SCp.ptr, wh->dma_bounce_buffer,
                       SCpnt->SCp.this_residual);
            kfree(wh->dma_bounce_buffer);
            wh->dma_bounce_buffer = NULL;
            wh->dma_bounce_len = 0;
        } else {
            kfree(wh->dma_bounce_buffer);
            wh->dma_bounce_buffer = NULL;
            wh->dma_bounce_len = 0;
        }
    }
}

static int a3000_bus_reset(struct scsi_cmnd *cmd)
{
    struct Scsi_Host *instance = cmd->device->host;

    /* FIXME perform bus-specific reset */

    /* FIXME 2: kill this entire function, which should
       cause mid-layer to call wd33c93_host_reset anyway? */

    spin_lock_irq(instance->host_lock);
    wd33c93_host_reset(cmd);
    spin_unlock_irq(instance->host_lock);

    return SUCCESS;
}

static struct scsi_host_template amiga_a3000_scsi_template = {
    .module         = THIS_MODULE,
    .name           = "Amiga 3000 built-in SCSI",
    .proc_info      = wd33c93_proc_info,
    .proc_name      = "A3000",
    .queuecommand       = wd33c93_queuecommand,
    .eh_abort_handler   = wd33c93_abort,
    .eh_bus_reset_handler   = a3000_bus_reset,
    .eh_host_reset_handler  = wd33c93_host_reset,
    .can_queue      = CAN_QUEUE,
    .this_id        = 7,
    .sg_tablesize       = SG_ALL,
    .cmd_per_lun        = CMD_PER_LUN,
    .use_clustering     = ENABLE_CLUSTERING
};

static int __init amiga_a3000_scsi_probe(struct platform_device *pdev)
{
    struct resource *res;
    struct Scsi_Host *instance;
    int error;
    struct a3000_scsiregs *regs;
    wd33c93_regs wdregs;
    struct a3000_hostdata *hdata;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res)
        return -ENODEV;

    if (!request_mem_region(res->start, resource_size(res), "wd33c93"))
        return -EBUSY;

    instance = scsi_host_alloc(&amiga_a3000_scsi_template,
                   sizeof(struct a3000_hostdata));
    if (!instance) {
        error = -ENOMEM;
        goto fail_alloc;
    }

    instance->irq = IRQ_AMIGA_PORTS;

    regs = (struct a3000_scsiregs *)ZTWO_VADDR(res->start);
    regs->DAWR = DAWR_A3000;

    wdregs.SASR = &regs->SASR;
    wdregs.SCMD = &regs->SCMD;

    hdata = shost_priv(instance);
    hdata->wh.no_sync = 0xff;
    hdata->wh.fast = 0;
    hdata->wh.dma_mode = CTRL_DMA;
    hdata->regs = regs;

    wd33c93_init(instance, wdregs, dma_setup, dma_stop, WD33C93_FS_12_15);
    error = request_irq(IRQ_AMIGA_PORTS, a3000_intr, IRQF_SHARED,
                "A3000 SCSI", instance);
    if (error)
        goto fail_irq;

    regs->CNTR = CNTR_PDMD | CNTR_INTEN;

    error = scsi_add_host(instance, NULL);
    if (error)
        goto fail_host;

    platform_set_drvdata(pdev, instance);

    scsi_scan_host(instance);
    return 0;

fail_host:
    free_irq(IRQ_AMIGA_PORTS, instance);
fail_irq:
    scsi_host_put(instance);
fail_alloc:
    release_mem_region(res->start, resource_size(res));
    return error;
}

static int __exit amiga_a3000_scsi_remove(struct platform_device *pdev)
{
    struct Scsi_Host *instance = platform_get_drvdata(pdev);
    struct a3000_hostdata *hdata = shost_priv(instance);
    struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

    hdata->regs->CNTR = 0;
    scsi_remove_host(instance);
    free_irq(IRQ_AMIGA_PORTS, instance);
    scsi_host_put(instance);
    release_mem_region(res->start, resource_size(res));
    return 0;
}

static struct platform_driver amiga_a3000_scsi_driver = {
    .remove = __exit_p(amiga_a3000_scsi_remove),
    .driver   = {
        .name   = "amiga-a3000-scsi",
        .owner  = THIS_MODULE,
    },
};

static int __init amiga_a3000_scsi_init(void)
{
    return platform_driver_probe(&amiga_a3000_scsi_driver,
                     amiga_a3000_scsi_probe);
}
module_init(amiga_a3000_scsi_init);

static void __exit amiga_a3000_scsi_exit(void)
{
    platform_driver_unregister(&amiga_a3000_scsi_driver);
}
module_exit(amiga_a3000_scsi_exit);

MODULE_DESCRIPTION("Amiga 3000 built-in SCSI");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:amiga-a3000-scsi");