jazz_esp.c

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/* jazz_esp.c: ESP front-end for MIPS JAZZ systems.
 *
 * Copyright (C) 2007 Thomas Bogendörfer ([email protected])
 */

#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>

#include <asm/irq.h>
#include <asm/io.h>
#include <asm/dma.h>

#include <asm/jazz.h>
#include <asm/jazzdma.h>

#include <scsi/scsi_host.h>

#include "esp_scsi.h"

#define DRV_MODULE_NAME     "jazz_esp"
#define PFX DRV_MODULE_NAME ": "
#define DRV_VERSION     "1.000"
#define DRV_MODULE_RELDATE  "May 19, 2007"

static void jazz_esp_write8(struct esp *esp, u8 val, unsigned long reg)
{
    *(volatile u8 *)(esp->regs + reg) = val;
}

static u8 jazz_esp_read8(struct esp *esp, unsigned long reg)
{
    return *(volatile u8 *)(esp->regs + reg);
}

static dma_addr_t jazz_esp_map_single(struct esp *esp, void *buf,
                      size_t sz, int dir)
{
    return dma_map_single(esp->dev, buf, sz, dir);
}

static int jazz_esp_map_sg(struct esp *esp, struct scatterlist *sg,
                  int num_sg, int dir)
{
    return dma_map_sg(esp->dev, sg, num_sg, dir);
}

static void jazz_esp_unmap_single(struct esp *esp, dma_addr_t addr,
                  size_t sz, int dir)
{
    dma_unmap_single(esp->dev, addr, sz, dir);
}

static void jazz_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
                  int num_sg, int dir)
{
    dma_unmap_sg(esp->dev, sg, num_sg, dir);
}

static int jazz_esp_irq_pending(struct esp *esp)
{
    if (jazz_esp_read8(esp, ESP_STATUS) & ESP_STAT_INTR)
        return 1;
    return 0;
}

static void jazz_esp_reset_dma(struct esp *esp)
{
    vdma_disable ((int)esp->dma_regs);
}

static void jazz_esp_dma_drain(struct esp *esp)
{
    /* nothing to do */
}

static void jazz_esp_dma_invalidate(struct esp *esp)
{
    vdma_disable ((int)esp->dma_regs);
}

static void jazz_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
                  u32 dma_count, int write, u8 cmd)
{
    BUG_ON(!(cmd & ESP_CMD_DMA));

    jazz_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
    jazz_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
    vdma_disable ((int)esp->dma_regs);
    if (write)
        vdma_set_mode ((int)esp->dma_regs, DMA_MODE_READ);
    else
        vdma_set_mode ((int)esp->dma_regs, DMA_MODE_WRITE);

    vdma_set_addr ((int)esp->dma_regs, addr);
    vdma_set_count ((int)esp->dma_regs, dma_count);
    vdma_enable ((int)esp->dma_regs);

    scsi_esp_cmd(esp, cmd);
}

static int jazz_esp_dma_error(struct esp *esp)
{
    u32 enable = vdma_get_enable((int)esp->dma_regs);

    if (enable & (R4030_MEM_INTR|R4030_ADDR_INTR))
        return 1;

    return 0;
}

static const struct esp_driver_ops jazz_esp_ops = {
    .esp_write8 =   jazz_esp_write8,
    .esp_read8  =   jazz_esp_read8,
    .map_single =   jazz_esp_map_single,
    .map_sg     =   jazz_esp_map_sg,
    .unmap_single   =   jazz_esp_unmap_single,
    .unmap_sg   =   jazz_esp_unmap_sg,
    .irq_pending    =   jazz_esp_irq_pending,
    .reset_dma  =   jazz_esp_reset_dma,
    .dma_drain  =   jazz_esp_dma_drain,
    .dma_invalidate =   jazz_esp_dma_invalidate,
    .send_dma_cmd   =   jazz_esp_send_dma_cmd,
    .dma_error  =   jazz_esp_dma_error,
};

static int __devinit esp_jazz_probe(struct platform_device *dev)
{
    struct scsi_host_template *tpnt = &scsi_esp_template;
    struct Scsi_Host *host;
    struct esp *esp;
    struct resource *res;
    int err;

    host = scsi_host_alloc(tpnt, sizeof(struct esp));

    err = -ENOMEM;
    if (!host)
        goto fail;

    host->max_id = 8;
    esp = shost_priv(host);

    esp->host = host;
    esp->dev = dev;
    esp->ops = &jazz_esp_ops;

    res = platform_get_resource(dev, IORESOURCE_MEM, 0);
    if (!res)
        goto fail_unlink;

    esp->regs = (void __iomem *)res->start;
    if (!esp->regs)
        goto fail_unlink;

    res = platform_get_resource(dev, IORESOURCE_MEM, 1);
    if (!res)
        goto fail_unlink;

    esp->dma_regs = (void __iomem *)res->start;

    esp->command_block = dma_alloc_coherent(esp->dev, 16,
                        &esp->command_block_dma,
                        GFP_KERNEL);
    if (!esp->command_block)
        goto fail_unmap_regs;

    host->irq = platform_get_irq(dev, 0);
    err = request_irq(host->irq, scsi_esp_intr, IRQF_SHARED, "ESP", esp);
    if (err < 0)
        goto fail_unmap_command_block;

    esp->scsi_id = 7;
    esp->host->this_id = esp->scsi_id;
    esp->scsi_id_mask = (1 << esp->scsi_id);
    esp->cfreq = 40000000;

    dev_set_drvdata(&dev->dev, esp);

    err = scsi_esp_register(esp, &dev->dev);
    if (err)
        goto fail_free_irq;

    return 0;

fail_free_irq:
    free_irq(host->irq, esp);
fail_unmap_command_block:
    dma_free_coherent(esp->dev, 16,
              esp->command_block,
              esp->command_block_dma);
fail_unmap_regs:
fail_unlink:
    scsi_host_put(host);
fail:
    return err;
}

static int __devexit esp_jazz_remove(struct platform_device *dev)
{
    struct esp *esp = dev_get_drvdata(&dev->dev);
    unsigned int irq = esp->host->irq;

    scsi_esp_unregister(esp);

    free_irq(irq, esp);
    dma_free_coherent(esp->dev, 16,
              esp->command_block,
              esp->command_block_dma);

    scsi_host_put(esp->host);

    return 0;
}

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:jazz_esp");

static struct platform_driver esp_jazz_driver = {
    .probe      = esp_jazz_probe,
    .remove     = __devexit_p(esp_jazz_remove),
    .driver = {
        .name   = "jazz_esp",
        .owner  = THIS_MODULE,
    },
};

static int __init jazz_esp_init(void)
{
    return platform_driver_register(&esp_jazz_driver);
}

static void __exit jazz_esp_exit(void)
{
    platform_driver_unregister(&esp_jazz_driver);
}

MODULE_DESCRIPTION("JAZZ ESP SCSI driver");
MODULE_AUTHOR("Thomas Bogendoerfer ([email protected])");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);

module_init(jazz_esp_init);
module_exit(jazz_esp_exit);