Add qemu 2.4.0

[kvmfornfv.git] / 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 (file)
index 0000000..84613b9
--- /dev/null
+++ b/qemu/roms/ipxe/src/drivers/nvs/spi.c
@@ -0,0 +1,141 @@
+/*
+ * 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.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stddef.h>
+#include <errno.h>
+#include <unistd.h>
+#include <ipxe/spi.h>
+
+/** @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;
+}
+