/**************************************************************************
*
* isapnp.c -- Etherboot isapnp support for the 3Com 3c515
* Written 2002-2003 by Timothy Legge <tlegge@rogers.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., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* Portions of this code:
* Copyright (C) 2001 P.J.H.Fox (fox@roestock.demon.co.uk)
*
*
* REVISION HISTORY:
* ================
* Version 0.1 April 26, 2002 TJL
* Version 0.2 01/08/2003 TJL Moved outside the 3c515.c driver file
* Version 0.3 Sept 23, 2003 timlegge Change delay to currticks
*
*
* Generalised into an ISAPnP bus that can be used by more than just
* the 3c515 by Michael Brown <mbrown@fensystems.co.uk>
*
***************************************************************************/
/** @file
*
* ISAPnP bus support
*
* Etherboot orignally gained ISAPnP support in a very limited way for
* the 3c515 NIC. The current implementation is almost a complete
* rewrite based on the ISAPnP specification, with passing reference
* to the Linux ISAPnP code.
*
* There can be only one ISAPnP bus in a system. Once the read port
* is known and all cards have been allocated CSNs, there's nothing to
* be gained by re-scanning for cards.
*
* External code (e.g. the ISAPnP ROM prefix) may already know the
* read port address, in which case it can store it in
* #isapnp_read_port. Note that setting the read port address in this
* way will prevent further isolation from taking place; you should
* set the read port address only if you know that devices have
* already been allocated CSNs.
*
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <ipxe/io.h>
#include <unistd.h>
#include <ipxe/isapnp.h>
/**
* ISAPnP Read Port address.
*
* ROM prefix may be able to set this address, which is why this is
* non-static.
*/
uint16_t isapnp_read_port;
static void isapnpbus_remove ( struct root_device *rootdev );
/*
* ISAPnP utility functions
*
*/
#define ISAPNP_CARD_ID_FMT "ID %04x:%04x (\"%s\") serial %x"
#define ISAPNP_CARD_ID_DATA(identifier) \
(identifier)->vendor_id, (identifier)->prod_id, \
isa_id_string ( (identifier)->vendor_id, (identifier)->prod_id ), \
(identifier)->serial
#define ISAPNP_DEV_ID_FMT "ID %04x:%04x (\"%s\")"
#define ISAPNP_DEV_ID_DATA(isapnp) \
(isapnp)->vendor_id, (isapnp)->prod_id, \
isa_id_string ( (isapnp)->vendor_id, (isapnp)->prod_id )
static inline void isapnp_write_address ( unsigned int address ) {
outb ( address, ISAPNP_ADDRESS );
}
static inline void isapnp_write_data ( unsigned int data ) {
outb ( data, ISAPNP_WRITE_DATA );
}
static inline unsigned int isapnp_read_data ( void ) {
return inb ( isapnp_read_port );
}
static inline void isapnp_write_byte ( unsigned int address,
unsigned int value ) {
isapnp_write_address ( address );
isapnp_write_data ( value );
}
static inline unsigned int isapnp_read_byte ( unsigned int address ) {
isapnp_write_address ( address );
return isapnp_read_data ();
}
static inline unsigned int isapnp_read_word ( unsigned int address ) {
/* Yes, they're in big-endian order */
return ( ( isapnp_read_byte ( address ) << 8 )
| isapnp_read_byte ( address + 1 ) );
}
/** Inform cards of a new read port address */
static inline void isapnp_set_read_port ( void ) {
isapnp_write_byte ( ISAPNP_READPORT, ( isapnp_read_port >> 2 ) );
}
/**
* Enter the Isolation state.
*
* Only cards currently in the Sleep state will respond to this
* command.
*/
static inline void isapnp_serialisolation ( void ) {
isapnp_write_address ( ISAPNP_SERIALISOLATION );
}
/**
* Enter the Wait for Key state.
*
* All cards will respond to this command, regardless of their current
* state.
*/
static inline void isapnp_wait_for_key ( void ) {
isapnp_write_byte ( ISAPNP_CONFIGCONTROL, ISAPNP_CONFIG_WAIT_FOR_KEY );
}
/**
* Reset (i.e. remove) Card Select Number.
*
* Only cards currently in the Sleep state will respond to this
* command.
*/
static inline void isapnp_reset_csn ( void ) {
isapnp_write_byte ( ISAPNP_CONFIGCONTROL, ISAPNP_CONFIG_RESET_CSN );
}
/**
* Place a specified card into the Config state.
*
* @v csn Card Select Number
* @ret None -
* @err None -
*
* Only cards currently in the Sleep, Isolation, or Config states will
* respond to this command. The card that has the specified CSN will
* enter the Config state, all other cards will enter the Sleep state.
*/
static inline void isapnp_wake ( uint8_t csn ) {
isapnp_write_byte ( ISAPNP_WAKE, csn );
}
static inline unsigned int isapnp_read_resourcedata ( void ) {
return isapnp_read_byte ( ISAPNP_RESOURCEDATA );
}
static inline unsigned int isapnp_read_status ( void ) {
return isapnp_read_byte ( ISAPNP_STATUS );
}
/**
* Assign a Card Select Number to a card, and enter the Config state.
*
* @v csn Card Select Number
*
* Only cards in the Isolation state will respond to this command.
* The isolation protocol is designed so that only one card will
* remain in the Isolation state by the time the isolation protocol
* completes.
*/
static inline void isapnp_write_csn ( unsigned int csn ) {
isapnp_write_byte ( ISAPNP_CARDSELECTNUMBER, csn );
}
static inline void isapnp_logicaldevice ( unsigned int logdev ) {
isapnp_write_byte ( ISAPNP_LOGICALDEVICENUMBER, logdev );
}
static inline void isapnp_activate ( unsigned int logdev ) {
isapnp_logicaldevice ( logdev );
isapnp_write_byte ( ISAPNP_ACTIVATE, 1 );
}
static inline void isapnp_deactivate ( unsigned int logdev ) {
isapnp_logicaldevice ( logdev );
isapnp_write_byte ( ISAPNP_ACTIVATE, 0 );
}
static inline unsigned int isapnp_read_iobase ( unsigned int index ) {
return isapnp_read_word ( ISAPNP_IOBASE ( index ) );
}
static inline unsigned int isapnp_read_irqno ( unsigned int index ) {
return isapnp_read_byte ( ISAPNP_IRQNO ( index ) );
}
static void isapnp_delay ( void ) {
udelay ( 1000 );
}
/**
* Linear feedback shift register.
*
* @v lfsr Current value of the LFSR
* @v input_bit Current input bit to the LFSR
* @ret lfsr Next value of the LFSR
*
* This routine implements the linear feedback shift register as
* described in Appendix B of the PnP ISA spec. The hardware
* implementation uses eight D-type latches and two XOR gates. I
* think this is probably the smallest possible implementation in
* software. Six instructions when input_bit is a constant 0 (for
* isapnp_send_key). :)
*/
static inline unsigned int isapnp_lfsr_next ( unsigned int lfsr,
unsigned int input_bit ) {
register uint8_t lfsr_next;
lfsr_next = lfsr >> 1;
lfsr_next |= ( ( ( lfsr ^ lfsr_next ) ^ input_bit ) ) << 7;
return lfsr_next;
}
/**
* Send the ISAPnP initiation key.
*
* Sending the key causes all ISAPnP cards that are currently in the
* Wait for Key state to transition into the Sleep state.
*/
static void isapnp_send_key ( void ) {
unsigned int i;
unsigned int lfsr;
isapnp_delay();
isapnp_write_address ( 0x00 );
isapnp_write_address ( 0x00 );
lfsr = ISAPNP_LFSR_SEED;
for ( i = 0 ; i < 32 ; i++ ) {
isapnp_write_address ( lfsr );
lfsr = isapnp_lfsr_next ( lfsr, 0 );
}
}
/**
* Compute ISAPnP identifier checksum
*
* @v identifier ISAPnP identifier
* @ret checksum Expected checksum value
*/
static unsigned int isapnp_checksum ( struct isapnp_identifier *identifier ) {
unsigned int i, j;
unsigned int lfsr;
unsigned int byte;
lfsr = ISAPNP_LFSR_SEED;
for ( i = 0 ; i < 8 ; i++ ) {
byte = * ( ( ( uint8_t * ) identifier ) + i );
for ( j = 0 ; j < 8 ; j++ ) {
lfsr = isapnp_lfsr_next ( lfsr, byte );
byte >>= 1;
}
}
return lfsr;
}
/*
* Read a byte of resource data from the current location
*
* @ret byte Byte of resource data
*/
static inline unsigned int isapnp_peek_byte ( void ) {
unsigned int i;
/* Wait for data to be ready */
for ( i = 0 ; i < 20 ; i++ ) {
if ( isapnp_read_status() & 0x01 ) {
/* Byte ready - read it */
return isapnp_read_resourcedata();
}
isapnp_delay();
}
/* Data never became ready - return 0xff */
return 0xff;
}
/**
* Read resource data.
*
* @v buf Buffer in which to store data, or NULL
* @v bytes Number of bytes to read
*
* Resource data is read from the current location. If #buf is NULL,
* the data is discarded.
*/
static void isapnp_peek ( void *buf, size_t len ) {
unsigned int i;
unsigned int byte;
for ( i = 0 ; i < len ; i++) {
byte = isapnp_peek_byte();
if ( buf )
* ( ( uint8_t * ) buf + i ) = byte;
}
}
/**
* Find a tag within the resource data.
*
* @v wanted_tag The tag that we're looking for
* @v buf Buffer in which to store the tag's contents
* @v len Length of buffer
* @ret rc Return status code
*
* Scan through the resource data until we find a particular tag, and
* read its contents into a buffer.
*/
static int isapnp_find_tag ( unsigned int wanted_tag, void *buf, size_t len ) {
unsigned int tag;
unsigned int tag_len;
DBG2 ( "ISAPnP read tag" );
do {
tag = isapnp_peek_byte();
if ( ISAPNP_IS_SMALL_TAG ( tag ) ) {
tag_len = ISAPNP_SMALL_TAG_LEN ( tag );
tag = ISAPNP_SMALL_TAG_NAME ( tag );
} else {
tag_len = ( isapnp_peek_byte() +
( isapnp_peek_byte() << 8 ) );
tag = ISAPNP_LARGE_TAG_NAME ( tag );
}
DBG2 ( " %02x (%02x)", tag, tag_len );
if ( tag == wanted_tag ) {
if ( len > tag_len )
len = tag_len;
isapnp_peek ( buf, len );
DBG2 ( "\n" );
return 0;
} else {
isapnp_peek ( NULL, tag_len );
}
} while ( tag != ISAPNP_TAG_END );
DBG2 ( "\n" );
return -ENOENT;
}
/**
* Find specified Logical Device ID tag
*
* @v logdev Logical device ID
* @v logdevid Logical device ID structure to fill in
* @ret rc Return status code
*/
static int isapnp_find_logdevid ( unsigned int logdev,
struct isapnp_logdevid *logdevid ) {
unsigned int i;
int rc;
for ( i = 0 ; i <= logdev ; i++ ) {
if ( ( rc = isapnp_find_tag ( ISAPNP_TAG_LOGDEVID, logdevid,
sizeof ( *logdevid ) ) ) != 0 )
return rc;
}
return 0;
}
/**
* Try isolating ISAPnP cards at the current read port.
*
* @ret \>0 Number of ISAPnP cards found
* @ret 0 There are no ISAPnP cards in the system
* @ret \<0 A conflict was detected; try a new read port
* @err None -
*
* The state diagram on page 18 (PDF page 24) of the PnP ISA spec
* gives the best overview of what happens here.
*/
static int isapnp_try_isolate ( void ) {
struct isapnp_identifier identifier;
unsigned int i, j;
unsigned int seen_55aa, seen_life;
unsigned int csn = 0;
unsigned int data;
unsigned int byte;
DBG ( "ISAPnP attempting isolation at read port %04x\n",
isapnp_read_port );
/* Place all cards into the Sleep state, whatever state
* they're currently in.
*/
isapnp_wait_for_key();
isapnp_send_key();
/* Reset all assigned CSNs */
isapnp_reset_csn();
isapnp_delay();
isapnp_delay();
/* Place all cards into the Isolation state */
isapnp_wait_for_key ();
isapnp_send_key();
isapnp_wake ( 0x00 );
/* Set the read port */
isapnp_set_read_port();
isapnp_delay();
while ( 1 ) {
/* All cards that do not have assigned CSNs are
* currently in the Isolation state, each time we go
* through this loop.
*/
/* Initiate serial isolation */
isapnp_serialisolation();
isapnp_delay();
/* Read identifier serially via the ISAPnP read port. */
memset ( &identifier, 0, sizeof ( identifier ) );
seen_55aa = seen_life = 0;
for ( i = 0 ; i < 9 ; i++ ) {
byte = 0;
for ( j = 0 ; j < 8 ; j++ ) {
data = isapnp_read_data();
isapnp_delay();
data = ( ( data << 8 ) | isapnp_read_data() );
isapnp_delay();
byte >>= 1;
if ( data != 0xffff ) {
seen_life++;
if ( data == 0x55aa ) {
byte |= 0x80;
seen_55aa++;
}
}
}
*( ( ( uint8_t * ) &identifier ) + i ) = byte;
}
/* If we didn't see any 55aa patterns, stop here */
if ( ! seen_55aa ) {
if ( csn ) {
DBG ( "ISAPnP found no more cards\n" );
} else {
if ( seen_life ) {
DBG ( "ISAPnP saw life but no cards, "
"trying new read port\n" );
csn = -1;
} else {
DBG ( "ISAPnP saw no signs of life, "
"abandoning isolation\n" );
}
}
break;
}
/* If the checksum was invalid stop here */
if ( identifier.checksum != isapnp_checksum ( &identifier) ) {
DBG ( "ISAPnP found malformed card "
ISAPNP_CARD_ID_FMT "\n with checksum %02x "
"(should be %02x), trying new read port\n",
ISAPNP_CARD_ID_DATA ( &identifier ),
identifier.checksum,
isapnp_checksum ( &identifier) );
csn = -1;
break;
}
/* Give the device a CSN */
csn++;
DBG ( "ISAPnP found card " ISAPNP_CARD_ID_FMT
", assigning CSN %02x\n",
ISAPNP_CARD_ID_DATA ( &identifier ), csn );
isapnp_write_csn ( csn );
isapnp_delay();
/* Send this card back to Sleep and force all cards
* without a CSN into Isolation state
*/
isapnp_wake ( 0x00 );
isapnp_delay();
}
/* Place all cards in Wait for Key state */
isapnp_wait_for_key();
/* Return number of cards found */
if ( csn > 0 ) {
DBG ( "ISAPnP found %d cards at read port %04x\n",
csn, isapnp_read_port );
}
return csn;
}
/**
* Find a valid read port and isolate all ISAPnP cards.
*
*/
static void isapnp_isolate ( void ) {
for ( isapnp_read_port = ISAPNP_READ_PORT_START ;
isapnp_read_port <= ISAPNP_READ_PORT_MAX ;
isapnp_read_port += ISAPNP_READ_PORT_STEP ) {
/* Avoid problematic locations such as the NE2000
* probe space
*/
if ( ( isapnp_read_port >= 0x280 ) &&
( isapnp_read_port <= 0x380 ) )
continue;
/* If we detect any ISAPnP cards at this location, stop */
if ( isapnp_try_isolate() >= 0 )
return;
}
}
/**
* Activate or deactivate an ISAPnP device.
*
* @v isapnp ISAPnP device
* @v activation True to enable, False to disable the device
* @ret None -
* @err None -
*
* This routine simply activates the device in its current
* configuration, or deactivates the device. It does not attempt any
* kind of resource arbitration.
*
*/
void isapnp_device_activation ( struct isapnp_device *isapnp,
int activation ) {
/* Wake the card and select the logical device */
isapnp_wait_for_key ();
isapnp_send_key ();
isapnp_wake ( isapnp->csn );
isapnp_logicaldevice ( isapnp->logdev );
/* Activate/deactivate the logical device */
isapnp_activate ( activation );
isapnp_delay();
/* Return all cards to Wait for Key state */
isapnp_wait_for_key ();
DBG ( "ISAPnP %s device %02x:%02x\n",
( activation ? "activated" : "deactivated" ),
isapnp->csn, isapnp->logdev );
}
/**
* Probe an ISAPnP device
*
* @v isapnp ISAPnP device
* @ret rc Return status code
*
* Searches for a driver for the ISAPnP device. If a driver is found,
* its probe() routine is called.
*/
static int isapnp_probe ( struct isapnp_device *isapnp ) {
struct isapnp_driver *driver;
struct isapnp_device_id *id;
unsigned int i;
int rc;
DBG ( "Adding ISAPnP device %02x:%02x (%04x:%04x (\"%s\") "
"io %x irq %d)\n", isapnp->csn, isapnp->logdev,
isapnp->vendor_id, isapnp->prod_id,
isa_id_string ( isapnp->vendor_id, isapnp->prod_id ),
isapnp->ioaddr, isapnp->irqno );
for_each_table_entry ( driver, ISAPNP_DRIVERS ) {
for ( i = 0 ; i < driver->id_count ; i++ ) {
id = &driver->ids[i];
if ( id->vendor_id != isapnp->vendor_id )
continue;
if ( ISA_PROD_ID ( id->prod_id ) !=
ISA_PROD_ID ( isapnp->prod_id ) )
continue;
isapnp->driver = driver;
isapnp->dev.driver_name = id->name;
DBG ( "...using driver %s\n", isapnp->dev.driver_name );
if ( ( rc = driver->probe ( isapnp, id ) ) != 0 ) {
DBG ( "......probe failed\n" );
continue;
}
return 0;
}
}
DBG ( "...no driver found\n" );
return -ENOTTY;
}
/**
* Remove an ISAPnP device
*
* @v isapnp ISAPnP device
*/
static void isapnp_remove ( struct isapnp_device *isapnp ) {
isapnp->driver->remove ( isapnp );
DBG ( "Removed ISAPnP device %02x:%02x\n",
isapnp->csn, isapnp->logdev );
}
/**
* Probe ISAPnP root bus
*
* @v rootdev ISAPnP bus root device
*
* Scans the ISAPnP bus for devices and registers all devices it can
* find.
*/
static int isapnpbus_probe ( struct root_device *rootdev ) {
struct isapnp_device *isapnp = NULL;
struct isapnp_identifier identifier;
struct isapnp_logdevid logdevid;
unsigned int csn;
unsigned int logdev;
int rc;
/* Perform isolation if it hasn't yet been done */
if ( ! isapnp_read_port )
isapnp_isolate();
for ( csn = 1 ; csn <= 0xff ; csn++ ) {
for ( logdev = 0 ; logdev <= 0xff ; logdev++ ) {
/* Allocate struct isapnp_device */
if ( ! isapnp )
isapnp = malloc ( sizeof ( *isapnp ) );
if ( ! isapnp ) {
rc = -ENOMEM;
goto err;
}
memset ( isapnp, 0, sizeof ( *isapnp ) );
isapnp->csn = csn;
isapnp->logdev = logdev;
/* Wake the card */
isapnp_wait_for_key();
isapnp_send_key();
isapnp_wake ( csn );
/* Read the card identifier */
isapnp_peek ( &identifier, sizeof ( identifier ) );
/* No card with this CSN; stop here */
if ( identifier.vendor_id & 0x80 )
goto done;
/* Find the Logical Device ID tag */
if ( ( rc = isapnp_find_logdevid ( logdev,
&logdevid ) ) != 0){
/* No more logical devices; go to next CSN */
break;
}
/* Select the logical device */
isapnp_logicaldevice ( logdev );
/* Populate struct isapnp_device */
isapnp->vendor_id = logdevid.vendor_id;
isapnp->prod_id = logdevid.prod_id;
isapnp->ioaddr = isapnp_read_iobase ( 0 );
isapnp->irqno = isapnp_read_irqno ( 0 );
/* Return all cards to Wait for Key state */
isapnp_wait_for_key();
/* Add to device hierarchy */
snprintf ( isapnp->dev.name,
sizeof ( isapnp->dev.name ),
"ISAPnP%02x:%02x", csn, logdev );
isapnp->dev.desc.bus_type = BUS_TYPE_ISAPNP;
isapnp->dev.desc.vendor = isapnp->vendor_id;
isapnp->dev.desc.device = isapnp->prod_id;
isapnp->dev.desc.ioaddr = isapnp->ioaddr;
isapnp->dev.desc.irq = isapnp->irqno;
isapnp->dev.parent = &rootdev->dev;
list_add ( &isapnp->dev.siblings,
&rootdev->dev.children );
INIT_LIST_HEAD ( &isapnp->dev.children );
/* Look for a driver */
if ( isapnp_probe ( isapnp ) == 0 ) {
/* isapnpdev registered, we can drop our ref */
isapnp = NULL;
} else {
/* Not registered; re-use struct */
list_del ( &isapnp->dev.siblings );
}
}
}
done:
free ( isapnp );
return 0;
err:
free ( isapnp );
isapnpbus_remove ( rootdev );
return rc;
}
/**
* Remove ISAPnP root bus
*
* @v rootdev ISAPnP bus root device
*/
static void isapnpbus_remove ( struct root_device *rootdev ) {
struct isapnp_device *isapnp;
struct isapnp_device *tmp;
list_for_each_entry_safe ( isapnp, tmp, &rootdev->dev.children,
dev.siblings ) {
isapnp_remove ( isapnp );
list_del ( &isapnp->dev.siblings );
free ( isapnp );
}
}
/** ISAPnP bus root device driver */
static struct root_driver isapnp_root_driver = {
.probe = isapnpbus_probe,
.remove = isapnpbus_remove,
};
/** ISAPnP bus root device */
struct root_device isapnp_root_device __root_device = {
.dev = { .name = "ISAPnP" },
.driver = &isapnp_root_driver,
};
