path: root/drivers/scsi/scsi_transport_spi.c

/* 
 *  Parallel SCSI (SPI) transport specific attributes exported to sysfs.
 *
 *  Copyright (c) 2003 Silicon Graphics, Inc.  All rights reserved.
 *  Copyright (c) 2004, 2005 James Bottomley <James.Bottomley@SteelEye.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/workqueue.h>
#include <linux/blkdev.h>
#include <asm/semaphore.h>
#include <scsi/scsi.h>
#include "scsi_priv.h"
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_spi.h>

#define SPI_NUM_ATTRS 14	/* increase this if you add attributes */
#define SPI_OTHER_ATTRS 1	/* Increase this if you add "always
				 * on" attributes */
#define SPI_HOST_ATTRS	1

#define SPI_MAX_ECHO_BUFFER_SIZE	4096

#define DV_LOOPS	3
#define DV_TIMEOUT	(10*HZ)
#define DV_RETRIES	3	/* should only need at most 
				 * two cc/ua clears */

/* Private data accessors (keep these out of the header file) */
#define spi_dv_pending(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_pending)
#define spi_dv_sem(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_sem)

struct spi_internal {
	struct scsi_transport_template t;
	struct spi_function_template *f;
	/* The actual attributes */
	struct class_device_attribute private_attrs[SPI_NUM_ATTRS];
	/* The array of null terminated pointers to attributes 
	 * needed by scsi_sysfs.c */
	struct class_device_attribute *attrs[SPI_NUM_ATTRS + SPI_OTHER_ATTRS + 1];
	struct class_device_attribute private_host_attrs[SPI_HOST_ATTRS];
	struct class_device_attribute *host_attrs[SPI_HOST_ATTRS + 1];
};

#define to_spi_internal(tmpl)	container_of(tmpl, struct spi_internal, t)

static const int ppr_to_ps[] = {
	/* The PPR values 0-6 are reserved, fill them in when
	 * the committee defines them */
	-1,			/* 0x00 */
	-1,			/* 0x01 */
	-1,			/* 0x02 */
	-1,			/* 0x03 */
	-1,			/* 0x04 */
	-1,			/* 0x05 */
	-1,			/* 0x06 */
	 3125,			/* 0x07 */
	 6250,			/* 0x08 */
	12500,			/* 0x09 */
	25000,			/* 0x0a */
	30300,			/* 0x0b */
	50000,			/* 0x0c */
};
/* The PPR values at which you calculate the period in ns by multiplying
 * by 4 */
#define SPI_STATIC_PPR	0x0c

static int sprint_frac(char *dest, int value, int denom)
{
	int frac = value % denom;
	int result = sprintf(dest, "%d", value / denom);

	if (frac == 0)
		return result;
	dest[result++] = '.';

	do {
		denom /= 10;
		sprintf(dest + result, "%d", frac / denom);
		result++;
		frac %= denom;
	} while (frac);

	dest[result++] = '\0';
	return result;
}

static int spi_execute(struct scsi_device *sdev, const void *cmd,
		       enum dma_data_direction dir,
		       void *buffer, unsigned bufflen,
		       struct scsi_sense_hdr *sshdr)
{
	int i, result;
	unsigned char sense[SCSI_SENSE_BUFFERSIZE];

	for(i = 0; i < DV_RETRIES; i++) {
		result = scsi_execute(sdev, cmd,