From e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb Mon Sep 17 00:00:00 2001 From: Yang Zhang Date: Fri, 28 Aug 2015 09:58:54 +0800 Subject: Add qemu 2.4.0 Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5 Signed-off-by: Yang Zhang --- qemu/roms/ipxe/src/drivers/nvs/spi.c | 141 +++++++++++++++++++++++++++++++++++ 1 file changed, 141 insertions(+) create mode 100644 qemu/roms/ipxe/src/drivers/nvs/spi.c (limited to 'qemu/roms/ipxe/src/drivers/nvs/spi.c') diff --git a/qemu/roms/ipxe/src/drivers/nvs/spi.c b/qemu/roms/ipxe/src/drivers/nvs/spi.c new file mode 100644 index 000000000..84613b9dd --- /dev/null +++ b/qemu/roms/ipxe/src/drivers/nvs/spi.c @@ -0,0 +1,141 @@ +/* + * Copyright (C) 2006 Michael Brown . + * + * 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. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include +#include +#include +#include + +/** @file + * + * SPI devices + * + */ + +/** + * Munge SPI device address into command + * + * @v command SPI command + * @v address Address + * @v munge_address Device requires address munging + * @ret command Actual SPI command to use + * + * Some devices with 9-bit addresses (e.g. AT25040A EEPROM) use bit 3 + * of the command byte as address bit A8, rather than having a + * two-byte address. This function takes care of generating the + * appropriate command. + */ +static inline unsigned int spi_command ( unsigned int command, + unsigned int address, + int munge_address ) { + return ( command | ( ( ( address >> 8 ) & munge_address ) << 3 ) ); +} + +/** + * Wait for SPI device to complete operation + * + * @v device SPI device + * @ret rc Return status code + */ +static int spi_wait ( struct spi_device *device ) { + struct spi_bus *bus = device->bus; + uint8_t status; + int i; + int rc; + + for ( i = 0 ; i < 50 ; i++ ) { + udelay ( 20 ); + if ( ( rc = bus->rw ( bus, device, SPI_RDSR, -1, NULL, + &status, sizeof ( status ) ) ) != 0 ) + return rc; + if ( ! ( status & SPI_STATUS_NRDY ) ) + return 0; + } + DBG ( "SPI %p timed out\n", device ); + return -ETIMEDOUT; +} + +/** + * Read data from SPI 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 spi_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; + unsigned int command = spi_command ( SPI_READ, address, + device->munge_address ); + int rc; + + DBG ( "SPI %p reading %zd bytes from %#04x\n", device, len, address ); + if ( ( rc = bus->rw ( bus, device, command, address, + NULL, data, len ) ) != 0 ) { + DBG ( "SPI %p failed to read data from device\n", device ); + return rc; + } + + return 0; +} + +/** + * Write data to SPI 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 spi_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; + unsigned int command = spi_command ( SPI_WRITE, address, + device->munge_address ); + int rc; + + DBG ( "SPI %p writing %zd bytes to %#04x\n", device, len, address ); + + if ( ( rc = bus->rw ( bus, device, SPI_WREN, -1, + NULL, NULL, 0 ) ) != 0 ) { + DBG ( "SPI %p failed to write-enable device\n", device ); + return rc; + } + + if ( ( rc = bus->rw ( bus, device, command, address, + data, NULL, len ) ) != 0 ) { + DBG ( "SPI %p failed to write data to device\n", device ); + return rc; + } + + if ( ( rc = spi_wait ( device ) ) != 0 ) { + DBG ( "SPI %p failed to complete write operation\n", device ); + return rc; + } + + return 0; +} + -- cgit 1.2.3-korg