cumana_2.c

一个2.4.21版本的嵌入式linux内核

/*
 *  linux/drivers/acorn/scsi/cumana_2.c
 *
 *  Copyright (C) 1997-2002 Russell King
 *
 * 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.
 *
 *  Changelog:
 *   30-08-1997	RMK	0.0.0	Created, READONLY version.
 *   22-01-1998	RMK	0.0.1	Updated to 2.1.80.
 *   15-04-1998	RMK	0.0.1	Only do PIO if FAS216 will allow it.
 *   02-05-1998	RMK	0.0.2	Updated & added DMA support.
 *   27-06-1998	RMK		Changed asm/delay.h to linux/delay.h
 *   18-08-1998	RMK	0.0.3	Fixed synchronous transfer depth.
 *   02-04-2000	RMK	0.0.4	Updated for new error handling code.
 */
#include <linux/module.h>
#include <linux/blk.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/init.h>

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

#include "../../scsi/sd.h"
#include "../../scsi/hosts.h"
#include "fas216.h"
#include "scsi.h"

#include <scsi/scsicam.h>

/*
 * List of devices that the driver will recognise
 */
#define CUMANASCSI2_LIST		{ MANU_CUMANA, PROD_CUMANA_SCSI_2 }

#define CUMANASCSI2_STATUS		(0)
#define STATUS_INT			(1 << 0)
#define STATUS_DRQ			(1 << 1)
#define STATUS_LATCHED			(1 << 3)

#define CUMANASCSI2_ALATCH		(5)
#define ALATCH_ENA_INT			(3)
#define ALATCH_DIS_INT			(2)
#define ALATCH_ENA_TERM			(5)
#define ALATCH_DIS_TERM			(4)
#define ALATCH_ENA_BIT32		(11)
#define ALATCH_DIS_BIT32		(10)
#define ALATCH_ENA_DMA			(13)
#define ALATCH_DIS_DMA			(12)
#define ALATCH_DMA_OUT			(15)
#define ALATCH_DMA_IN			(14)

#define CUMANASCSI2_PSEUDODMA		(0x80)

#define CUMANASCSI2_FAS216_OFFSET	(0xc0)
#define CUMANASCSI2_FAS216_SHIFT	0

/*
 * Version
 */
#define VERSION "1.00 (13/11/2002 2.4.19-rmk5)"

/*
 * Use term=0,1,0,0,0 to turn terminators on/off
 */
static int term[MAX_ECARDS] = { 1, 1, 1, 1, 1, 1, 1, 1 };

#define NR_SG	256

struct cumanascsi2_info {
	FAS216_Info		info;
	struct expansion_card	*ec;

	unsigned int		status;		/* card status register	*/
	unsigned int		alatch;		/* Control register	*/
	unsigned int		terms;		/* Terminator state	*/
	unsigned int		dmaarea;	/* Pseudo DMA area	*/
	struct scatterlist	sg[NR_SG];	/* Scatter DMA list	*/
};

#define CSTATUS_IRQ	(1 << 0)
#define CSTATUS_DRQ	(1 << 1)

/* Prototype: void cumanascsi_2_irqenable(ec, irqnr)
 * Purpose  : Enable interrupts on Cumana SCSI 2 card
 * Params   : ec    - expansion card structure
 *          : irqnr - interrupt number
 */
static void
cumanascsi_2_irqenable(struct expansion_card *ec, int irqnr)
{
	unsigned int port = (unsigned int)ec->irq_data;
	outb(ALATCH_ENA_INT, port);
}

/* Prototype: void cumanascsi_2_irqdisable(ec, irqnr)
 * Purpose  : Disable interrupts on Cumana SCSI 2 card
 * Params   : ec    - expansion card structure
 *          : irqnr - interrupt number
 */
static void
cumanascsi_2_irqdisable(struct expansion_card *ec, int irqnr)
{
	unsigned int port = (unsigned int)ec->irq_data;
	outb(ALATCH_DIS_INT, port);
}

static const expansioncard_ops_t cumanascsi_2_ops = {
	.irqenable	= cumanascsi_2_irqenable,
	.irqdisable	= cumanascsi_2_irqdisable,
};

/* Prototype: void cumanascsi_2_terminator_ctl(host, on_off)
 * Purpose  : Turn the Cumana SCSI 2 terminators on or off
 * Params   : host   - card to turn on/off
 *          : on_off - !0 to turn on, 0 to turn off
 */
static void
cumanascsi_2_terminator_ctl(struct Scsi_Host *host, int on_off)
{
	struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;

	if (on_off) {
		info->terms = 1;
		outb (ALATCH_ENA_TERM, info->alatch);
	} else {
		info->terms = 0;
		outb (ALATCH_DIS_TERM, info->alatch);
	}
}

/* Prototype: void cumanascsi_2_intr(irq, *dev_id, *regs)
 * Purpose  : handle interrupts from Cumana SCSI 2 card
 * Params   : irq    - interrupt number
 *	      dev_id - user-defined (Scsi_Host structure)
 *	      regs   - processor registers at interrupt
 */
static void
cumanascsi_2_intr(int irq, void *dev_id, struct pt_regs *regs)
{
	fas216_intr(dev_id);
}

/* Prototype: fasdmatype_t cumanascsi_2_dma_setup(host, SCpnt, direction, min_type)
 * Purpose  : initialises DMA/PIO
 * Params   : host      - host
 *	      SCpnt     - command
 *	      direction - DMA on to/off of card
 *	      min_type  - minimum DMA support that we must have for this transfer
 * Returns  : type of transfer to be performed
 */
static fasdmatype_t
cumanascsi_2_dma_setup(struct Scsi_Host *host, Scsi_Pointer *SCp,
		       fasdmadir_t direction, fasdmatype_t min_type)
{
	struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;
	int dmach = host->dma_channel;

	outb(ALATCH_DIS_DMA, info->alatch);

	if (dmach != NO_DMA &&
	    (min_type == fasdma_real_all || SCp->this_residual >= 512)) {
		int bufs, map_dir, dma_dir, alatch_dir;

		bufs = copy_SCp_to_sg(&info->sg[0], SCp, NR_SG);

		if (direction == DMA_OUT)
			map_dir = PCI_DMA_TODEVICE,
			dma_dir = DMA_MODE_WRITE,
			alatch_dir = ALATCH_DMA_OUT;
		else
			map_dir = PCI_DMA_FROMDEVICE,
			dma_dir = DMA_MODE_READ,
			alatch_dir = ALATCH_DMA_IN;

		pci_map_sg(NULL, info->sg, bufs, map_dir);

		disable_dma(dmach);
		set_dma_sg(dmach, info->sg, bufs);
		outb(alatch_dir, info->alatch);
		set_dma_mode(dmach, dma_dir);
		enable_dma(dmach);
		outb(ALATCH_ENA_DMA, info->alatch);
		outb(ALATCH_DIS_BIT32, info->alatch);
		return fasdma_real_all;
	}

	/*
	 * If we're not doing DMA,
	 *  we'll do pseudo DMA
	 */
	return fasdma_pio;
}

/*
 * Prototype: void cumanascsi_2_dma_pseudo(host, SCpnt, direction, transfer)
 * Purpose  : handles pseudo DMA
 * Params   : host      - host
 *	      SCpnt     - command
 *	      direction - DMA on to/off of card
 *	      transfer  - minimum number of bytes we expect to transfer
 */
static void
cumanascsi_2_dma_pseudo(struct Scsi_Host *host, Scsi_Pointer *SCp,
			fasdmadir_t direction, int transfer)
{
	struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;
	unsigned int length;
	unsigned char *addr;

	length = SCp->this_residual;
	addr = SCp->ptr;

	if (direction == DMA_OUT)
#if 0
		while (length > 1) {
			unsigned long word;
			unsigned int status = inb(info->status);

			if (status & STATUS_INT)
				goto end;

			if (!(status & STATUS_DRQ))
				continue;

			word = *addr | *(addr + 1) << 8;
			outw (info->dmaarea);
			addr += 2;
			length -= 2;
		}
#else
		printk ("PSEUDO_OUT???\n");
#endif
	else {
		if (transfer && (transfer & 255)) {
			while (length >= 256) {
				unsigned int status = inb(info->status);

				if (status & STATUS_INT)
					return;
	    
				if (!(status & STATUS_DRQ))
					continue;

				insw(info->dmaarea, addr, 256 >> 1);
				addr += 256;
				length -= 256;
			}
		}

		while (length > 0) {
			unsigned long word;
			unsigned int status = inb(info->status);

			if (status & STATUS_INT)
				return;

			if (!(status & STATUS_DRQ))
				continue;

			word = inw (info->dmaarea);
			*addr++ = word;
			if (--length > 0) {
				*addr++ = word >> 8;
				length --;
			}
		}
	}
}

/* Prototype: int cumanascsi_2_dma_stop(host, SCpnt)
 * Purpose  : stops DMA/PIO
 * Params   : host  - host
 *	      SCpnt - command
 */
static void
cumanascsi_2_dma_stop(struct Scsi_Host *host, Scsi_Pointer *SCp)
{
	struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;
	if (host->dma_channel != NO_DMA) {
		outb(ALATCH_DIS_DMA, info->alatch);
		disable_dma(host->dma_channel);
	}
}

/* Prototype: const char *cumanascsi_2_info(struct Scsi_Host * host)
 * Purpose  : returns a descriptive string about this interface,
 * Params   : host - driver host structure to return info for.
 * Returns  : pointer to a static buffer containing null terminated string.
 */
const char *cumanascsi_2_info(struct Scsi_Host *host)
{
	struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;
	static char string[150];

	sprintf(string, "%s (%s) in slot %d v%s terminators o%s",
		host->hostt->name, info->info.scsi.type, info->ec->slot_no,
		VERSION, info->terms ? "n" : "ff");

	return string;
}