12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788 |
- /*
- * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
- #include <stddef.h>
- #include <assert.h>
- #include <timer.h>
- #include <gpxe/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;
-
- assert ( bus->mode == SPI_MODE_THREEWIRE );
-
- DBG ( "3wire %p reading %zd bytes at %04x\n", device, len, address );
-
- return bus->rw ( bus, device, THREEWIRE_READ, address,
- NULL, data, len );
- }
-
- /**
- * 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 );
-
- DBG ( "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 )
- return rc;
-
- /* Write data */
- if ( ( rc = bus->rw ( bus, device, THREEWIRE_WRITE, address,
- data, NULL, len ) ) != 0 )
- 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;
- }
|