137 lines
3.8 KiB
C
137 lines
3.8 KiB
C
/*
|
|
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
|
|
*
|
|
* 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 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.
|
|
*
|
|
* You can also choose to distribute this program under the terms of
|
|
* the Unmodified Binary Distribution Licence (as given in the file
|
|
* COPYING.UBDL), provided that you have satisfied its requirements.
|
|
*/
|
|
|
|
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
|
|
|
|
#include <stddef.h>
|
|
#include <string.h>
|
|
#include <assert.h>
|
|
#include <unistd.h>
|
|
#include <ipxe/threewire.h>
|
|
|
|
/** @file
|
|
*
|
|
* Three-wire serial devices
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* Read data from three-wire device
|
|
*
|
|
* @v nvs NVS device
|
|
* @v address Address from which to read
|
|
* @v data Data buffer
|
|
* @v len Length of data buffer
|
|
* @ret rc Return status code
|
|
*/
|
|
int threewire_read ( struct nvs_device *nvs, unsigned int address,
|
|
void *data, size_t len ) {
|
|
struct spi_device *device = nvs_to_spi ( nvs );
|
|
struct spi_bus *bus = device->bus;
|
|
int rc;
|
|
|
|
assert ( bus->mode == SPI_MODE_THREEWIRE );
|
|
|
|
DBGC ( device, "3wire %p reading %zd bytes at %04x\n",
|
|
device, len, address );
|
|
|
|
if ( ( rc = bus->rw ( bus, device, THREEWIRE_READ, address,
|
|
NULL, data, len ) ) != 0 ) {
|
|
DBGC ( device, "3wire %p could not read: %s\n",
|
|
device, strerror ( rc ) );
|
|
return rc;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Write data to three-wire device
|
|
*
|
|
* @v nvs NVS device
|
|
* @v address Address from which to read
|
|
* @v data Data buffer
|
|
* @v len Length of data buffer
|
|
* @ret rc Return status code
|
|
*/
|
|
int threewire_write ( struct nvs_device *nvs, unsigned int address,
|
|
const void *data, size_t len ) {
|
|
struct spi_device *device = nvs_to_spi ( nvs );
|
|
struct spi_bus *bus = device->bus;
|
|
int rc;
|
|
|
|
assert ( bus->mode == SPI_MODE_THREEWIRE );
|
|
|
|
DBGC ( device, "3wire %p writing %zd bytes at %04x\n",
|
|
device, len, address );
|
|
|
|
/* Enable device for writing */
|
|
if ( ( rc = bus->rw ( bus, device, THREEWIRE_EWEN,
|
|
THREEWIRE_EWEN_ADDRESS, NULL, NULL, 0 ) ) != 0 ){
|
|
DBGC ( device, "3wire %p could not enable writing: %s\n",
|
|
device, strerror ( rc ) );
|
|
return rc;
|
|
}
|
|
|
|
/* Write data */
|
|
if ( ( rc = bus->rw ( bus, device, THREEWIRE_WRITE, address,
|
|
data, NULL, len ) ) != 0 ) {
|
|
DBGC ( device, "3wire %p could not write: %s\n",
|
|
device, strerror ( rc ) );
|
|
return rc;
|
|
}
|
|
|
|
/* Our model of an SPI bus doesn't provide a mechanism for
|
|
* "assert CS, wait for MISO to become high, so just wait for
|
|
* long enough to ensure that the write has completed.
|
|
*/
|
|
mdelay ( THREEWIRE_WRITE_MDELAY );
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Autodetect device address length
|
|
*
|
|
* @v device SPI device
|
|
* @ret rc Return status code
|
|
*/
|
|
int threewire_detect_address_len ( struct spi_device *device ) {
|
|
struct nvs_device *nvs = &device->nvs;
|
|
int rc;
|
|
|
|
DBGC ( device, "3wire %p autodetecting address length\n", device );
|
|
|
|
device->address_len = SPI_AUTODETECT_ADDRESS_LEN;
|
|
if ( ( rc = threewire_read ( nvs, 0, NULL,
|
|
( 1 << nvs->word_len_log2 ) ) ) != 0 ) {
|
|
DBGC ( device, "3wire %p could not autodetect address "
|
|
"length: %s\n", device, strerror ( rc ) );
|
|
return rc;
|
|
}
|
|
|
|
DBGC ( device, "3wire %p autodetected address length %d\n",
|
|
device, device->address_len );
|
|
return 0;
|
|
}
|