/* *  linux/arch/arm/kernel/dma-isa.c * *  Copyright (C) 1999-2000 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. * *  ISA DMA primitives *  Taken from various sources, including: *   linux/include/asm/dma.h: Defines for using and allocating dma channels. *     Written by Hennus Bergman, 1992. *     High DMA channel support & info by Hannu Savolainen and John Boyd, *     Nov. 1992. *   arch/arm/kernel/dma-ebsa285.c *   Copyright (C) 1998 Phil Blundell */#include <linux/ioport.h>#include <linux/init.h>#include <linux/pci.h>#include <asm/dma.h>#include <asm/io.h>#include <asm/mach/dma.h>#define ISA_DMA_MODE_READ	0x44#define ISA_DMA_MODE_WRITE	0x48#define ISA_DMA_MODE_CASCADE	0xc0#define ISA_DMA_AUTOINIT	0x10#define ISA_DMA_MASK		0#define ISA_DMA_MODE		1#define ISA_DMA_CLRFF		2#define ISA_DMA_PGHI		3#define ISA_DMA_PGLO		4#define ISA_DMA_ADDR		5#define ISA_DMA_COUNT		6static unsigned int isa_dma_port[8][7] = {	/* MASK   MODE   CLRFF  PAGE_HI PAGE_LO ADDR COUNT */	{  0x0a,  0x0b,  0x0c,  0x487,  0x087,  0x00, 0x01 },	{  0x0a,  0x0b,  0x0c,  0x483,  0x083,  0x02, 0x03 },	{  0x0a,  0x0b,  0x0c,  0x481,  0x081,  0x04, 0x05 },	{  0x0a,  0x0b,  0x0c,  0x482,  0x082,  0x06, 0x07 },	{  0xd4,  0xd6,  0xd8,  0x000,  0x000,  0xc0, 0xc2 },	{  0xd4,  0xd6,  0xd8,  0x48b,  0x08b,  0xc4, 0xc6 },	{  0xd4,  0xd6,  0xd8,  0x489,  0x089,  0xc8, 0xca },	{  0xd4,  0xd6,  0xd8,  0x48a,  0x08a,  0xcc, 0xce }};static int isa_get_dma_residue(dmach_t channel, dma_t *dma){	unsigned int io_port = isa_dma_port[channel][ISA_DMA_COUNT];	int count;	count = 1 + inb(io_port);	count |= inb(io_port) << 8;	return channel < 4 ? count : (count << 1);}static void isa_enable_dma(dmach_t channel, dma_t *dma){	if (dma->invalid) {		unsigned long address, length;		unsigned int mode, direction;		mode = channel & 3;		switch (dma->dma_mode & DMA_MODE_MASK) {		case DMA_MODE_READ:			mode |= ISA_DMA_MODE_READ;			direction = PCI_DMA_FROMDEVICE;			break;		case DMA_MODE_WRITE:			mode |= ISA_DMA_MODE_WRITE;			direction = PCI_DMA_TODEVICE;			break;		case DMA_MODE_CASCADE:			mode |= ISA_DMA_MODE_CASCADE;			direction = PCI_DMA_BIDIRECTIONAL;			break;		default:			direction = PCI_DMA_NONE;			break;		}		if (!dma->using_sg) {			/*			 * Cope with ISA-style drivers which expect cache			 * coherence.			 */			dma->buf.dma_address = pci_map_single(NULL,				dma->buf.__address, dma->buf.length,				direction);		}		address = dma->buf.dma_address;		length  = dma->buf.length - 1;		outb(address >> 16, isa_dma_port[channel][ISA_DMA_PGLO]);		outb(address >> 24, isa_dma_port[channel][ISA_DMA_PGHI]);		if (channel >= 4) {			address >>= 1;			length >>= 1;		}		outb(0, isa_dma_port[channel][ISA_DMA_CLRFF]);		outb(address, isa_dma_port[channel][ISA_DMA_ADDR]);		outb(address >> 8, isa_dma_port[channel][ISA_DMA_ADDR]);		outb(length, isa_dma_port[channel][ISA_DMA_COUNT]);		outb(length >> 8, isa_dma_port[channel][ISA_DMA_COUNT]);		if (dma->dma_mode & DMA_AUTOINIT)			mode |= ISA_DMA_AUTOINIT;		outb(mode, isa_dma_port[channel][ISA_DMA_MODE]);		dma->invalid = 0;	}	outb(channel & 3, isa_dma_port[channel][ISA_DMA_MASK]);}static void isa_disable_dma(dmach_t channel, dma_t *dma){	outb(channel | 4, isa_dma_port[channel][ISA_DMA_MASK]);}static struct dma_ops isa_dma_ops = {	.type		= "ISA",	.enable		= isa_enable_dma,	.disable	= isa_disable_dma,	.residue	= isa_get_dma_residue,};static struct resource dma_resources[] = {	{ "dma1",		0x0000, 0x000f },	{ "dma low page", 	0x0080, 0x008f },	{ "dma2",		0x00c0, 0x00df },	{ "dma high page",	0x0480, 0x048f }};void __init isa_init_dma(dma_t *dma){	/*	 * Try to autodetect presence of an ISA DMA controller.	 * We do some minimal initialisation, and check that	 * channel 0's DMA address registers are writeable.	 */	outb(0xff, 0x0d);	outb(0xff, 0xda);	/*	 * Write high and low address, and then read them back	 * in the same order.	 */	outb(0x55, 0x00);	outb(0xaa, 0x00);	if (inb(0) == 0x55 && inb(0) == 0xaa) {		int channel, i;		for (channel = 0; channel < 8; channel++) {			dma[channel].d_ops = &isa_dma_ops;			isa_disable_dma(channel, NULL);		}		outb(0x40, 0x0b);		outb(0x41, 0x0b);		outb(0x42, 0x0b);		outb(0x43, 0x0b);		outb(0xc0, 0xd6);		outb(0x41, 0xd6);		outb(0x42, 0xd6);		outb(0x43, 0xd6);		outb(0, 0xd4);		outb(0x10, 0x08);		outb(0x10, 0xd0);		/*		 * Is this correct?  According to my documentation, it		 * doesn't appear to be.  It should be:		 *  outb(0x3f, 0x40b); outb(0x3f, 0x4d6);		 */		outb(0x30, 0x40b);		outb(0x31, 0x40b);		outb(0x32, 0x40b);		outb(0x33, 0x40b);		outb(0x31, 0x4d6);		outb(0x32, 0x4d6);		outb(0x33, 0x4d6);		request_dma(DMA_ISA_CASCADE, "cascade");		for (i = 0; i < sizeof(dma_resources) / sizeof(dma_resources[0]); i++)			request_resource(&ioport_resource, dma_resources + i);	}}