linux-imx

/*

 * atari_scsi.c -- Device dependent functions for the Atari generic SCSI port

 *

 * Copyright 1994 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>

 *

 *   Loosely based on the work of Robert De Vries' team and added:

 *    - working real DMA

 *    - Falcon support (untested yet!)   ++bjoern fixed and now it works

 *    - lots of extensions and bug fixes.

 *

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file COPYING in the main directory of this archive

 * for more details.

 *

 */

​

/*

 * Notes for Falcon SCSI DMA

 *

 * The 5380 device is one of several that all share the DMA chip. Hence

 * "locking" and "unlocking" access to this chip is required.

 *

 * Two possible schemes for ST DMA acquisition by atari_scsi are:

 * 1) The lock is taken for each command separately (i.e. can_queue == 1).

 * 2) The lock is taken when the first command arrives and released

 * when the last command is finished (i.e. can_queue > 1).

 *

 * The first alternative limits SCSI bus utilization, since interleaving

 * commands is not possible. The second gives better performance but is

 * unfair to other drivers needing to use the ST DMA chip. In order to

 * allow the IDE and floppy drivers equal access to the ST DMA chip

 * the default is can_queue == 1.

 */

​

#include <linux/module.h>

#include <linux/types.h>

#include <linux/blkdev.h>

#include <linux/interrupt.h>

#include <linux/init.h>

#include <linux/nvram.h>

#include <linux/bitops.h>

#include <linux/wait.h>

#include <linux/platform_device.h>

​

#include <asm/setup.h>

#include <asm/atarihw.h>

#include <asm/atariints.h>

#include <asm/atari_stdma.h>

#include <asm/atari_stram.h>

#include <asm/io.h>

​

#include <scsi/scsi_host.h>

​

#define DMA_MIN_SIZE                    32

​

/* Definitions for the core NCR5380 driver. */

​

#define NCR5380_implementation_fields   /* none */

​

static u8 (*atari_scsi_reg_read)(unsigned int);

static void (*atari_scsi_reg_write)(unsigned int, u8);

​

#define NCR5380_read(reg)               atari_scsi_reg_read(reg)