io_microdev.c

linux-2.4.29操作系统的源码

/* 
 * linux/arch/sh/kernel/io_microdev.c
 *
 * Copyright (C) 2003 Sean McGoogan ([e-mail])
 *
 * SuperH SH4-202 MicroDev board support.
 *
 * May be copied or modified under the terms of the GNU General Public
 * License.  See linux/COPYING for more information.
 */

#include <linux/config.h>
#include <linux/init.h>
#include <asm/io.h>


	/*
	 *	we need to have a 'safe' address to re-direct all I/O requests
	 *	that we do not explicitly wish to handle. This safe address
	 *	must have the following properies:
	 *
	 *		* writes are ignored (no exception)
	 *		* reads are benign (no side-effects)
	 *		* accesses of width 1, 2 and 4-bytes are all valid.
	 *
	 *	The Processor Version Register (PVR) has these properties.
	 */
#define	PVR	0xff000030	/* Processor Version Register */


#define	IO_LAN91C111	0x300ul	/* I/O port for SMSC  LAN91C111 Ethernet chip */

#define PORT2ADDR(x) (microdev_isa_port2addr(x))


static inline void delay(void)
{
	ctrl_inw(0xa0000000);
}

unsigned char microdev_inb(unsigned long port)
{
	return *(volatile unsigned char*)PORT2ADDR(port);
}

unsigned short microdev_inw(unsigned long port)
{
	return *(volatile unsigned short*)PORT2ADDR(port);
}

unsigned int microdev_inl(unsigned long port)
{
	return *(volatile unsigned int*)PORT2ADDR(port);
}

void microdev_outb(unsigned char b, unsigned long port)
{
		/*
		 *	There is a board feature with the current SH4-202 MicroDev 
		 *	in that the 2 byte enables (nBE0 and nBE1) are tied together (and to the 
		 *	Chip Select Line (Ethernet_CS)). Due to this conectivity, it is not possible
		 *	to safely perform 8-bit writes to the Ethernet registers, as 16-bits
		 *	will be consumed from the Data lines (corrupting the other byte).
		 *	Hence, this function is written to impliment 16-bit read/modify/write
		 *	for all byte-wide acceses.
		 *
		 *	Note: there is no problem with byte READS (even or odd).
		 *
		 *			Sean McGoogan - 16th June 2003.
		 */
	if ( (port>=IO_LAN91C111) && (port<IO_LAN91C111+0x10ul) )
	{
			/*
			 * Then are trying to perform a byte-write to the LAN91C111.
			 * This needs special care.
			 */
		if (port%2==1)					/* is the port odd ? */
		{
			const unsigned long evenPort = port-1;	/* unset bit-0, i.e. make even */
			unsigned short word;			/* temp variable */
				/*
				 * do a 16-bit read/write to write to 'port', preserving even byte.
				 *	Even addresses are bits 0-7
				 *	Odd  addresses are bits 8-15
				 */
			word = microdev_inw(evenPort);
			word = (word & 0xffu) | (b << 8);
			microdev_outw(word, evenPort);
		}
		else	/* else, we are trying to do an even byte write */
		{
			unsigned short word;			/* temp variable */
				/*
				 * do a 16-bit read/write to write to 'port', preserving odd byte.
				 *	Even addresses are bits 0-7
				 *	Odd  addresses are bits 8-15
				 */
			word = microdev_inw(port);
			word = (word & 0xff00u) | (b);
			microdev_outw(word, port);
		}
	}
	else
	{
		*(volatile unsigned char*)PORT2ADDR(port) = b;
	}
}

void microdev_outw(unsigned short b, unsigned long port)
{
	*(volatile unsigned short*)PORT2ADDR(port) = b;
}

void microdev_outl(unsigned int b, unsigned long port)
{
        *(volatile unsigned int*)PORT2ADDR(port) = b;
}

unsigned char microdev_inb_p(unsigned long port)
{
	unsigned char v = microdev_inb(port);
	delay();
	return v;
}

unsigned short microdev_inw_p(unsigned long port)
{
	unsigned short v = microdev_inw(port);
	delay();
	return v;
}

unsigned int microdev_inl_p(unsigned long port)
{
	unsigned int v = microdev_inl(port);
	delay();
	return v;
}

void microdev_outb_p(unsigned char b, unsigned long port)
{
	microdev_outb(b, port);
	delay();
}

void microdev_outw_p(unsigned short b, unsigned long port)
{
	microdev_outw(b, port);
	delay();
}

void microdev_outl_p(unsigned int b, unsigned long port)
{
	microdev_outl(b, port);
	delay();
}

void microdev_insb(unsigned long port, void *buffer, unsigned long count)
{
	unsigned char *buf=buffer;
	while(count--) *buf++=microdev_inb(port);
}

void microdev_insw(unsigned long port, void *buffer, unsigned long count)
{
	unsigned short *buf=buffer;
	while(count--) *buf++=microdev_inw(port);
}

void microdev_insl(unsigned long port, void *buffer, unsigned long count)
{
	unsigned int *buf=buffer;
	while(count--) *buf++=microdev_inl(port);
}

void microdev_outsb(unsigned long port, const void *buffer, unsigned long count)
{
	const unsigned char *buf=buffer;
	while(count--) microdev_outb(*buf++, port);
}

void microdev_outsw(unsigned long port, const void *buffer, unsigned long count)
{
	const unsigned short *buf=buffer;
	while(count--) microdev_outw(*buf++, port);
}

void microdev_outsl(unsigned long port, const void *buffer, unsigned long count)
{
	const unsigned int *buf=buffer;
	while(count--) microdev_outl(*buf++, port);
}


/*
 * map I/O ports to memory-mapped addresses 
 */
unsigned long microdev_isa_port2addr(unsigned long offset)
{
	unsigned long result;

	if ( (offset>=IO_LAN91C111) && (offset<IO_LAN91C111+0x10ul) )
	{
			/*
			 *	SMSC LAN91C111 Ethernet chip
			 */
		result = 0xa7500000ul + offset - IO_LAN91C111;
	}
	else /* if (offset <= 0xfffful) */
	{
			/*
			 *	safe default.
			 */
		result = PVR;
	}

	return result;
}