1 files changed, 47 insertions, 6 deletions

diff --git a/src/drivers/nvs/threewire.c b/src/drivers/nvs/threewire.c
index f7a20bbef..8e5213893 100644
--- a/src/drivers/nvs/threewire.c
+++ b/src/drivers/nvs/threewire.c
@@ -19,6 +19,7 @@
 FILE_LICENCE ( GPL2_OR_LATER );
 
 #include <stddef.h>
+#include <string.h>
 #include <assert.h>
 #include <unistd.h>
 #include <gpxe/threewire.h>
@@ -42,13 +43,21 @@ 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 );
 
-	DBG ( "3wire %p reading %zd bytes at %04x\n", device, len, address );
+	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 bus->rw ( bus, device, THREEWIRE_READ, address,
-			 NULL, data, len );
+	return 0;
 }
 
 /**
@@ -68,17 +77,24 @@ int threewire_write ( struct nvs_device *nvs, unsigned int address,
 
 	assert ( bus->mode == SPI_MODE_THREEWIRE );
 
-	DBG ( "3wire %p writing %zd bytes at %04x\n", device, len, address );
+	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 )
+			      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 )
+			      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
@@ -88,3 +104,28 @@ int threewire_write ( struct nvs_device *nvs, unsigned int address,
 
 	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;
+}