net: ethernet: enc28j60: support half-duplex SPI controllers
The current spi_read_buf function fails on SPI host masters which
are only half-duplex capable. Splitting the Tx and Rx part solves
this issue.
Tested on Raspberry Pi (full duplex) and I2SE Duckbill (half duplex).
Signed-off-by: Michael Heimpold <mhei@heimpold.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/microchip/enc28j60.c b/drivers/net/ethernet/microchip/enc28j60.c
index 86ea17e..b723622 100644
--- a/drivers/net/ethernet/microchip/enc28j60.c
+++ b/drivers/net/ethernet/microchip/enc28j60.c
@@ -89,22 +89,26 @@
{
u8 *rx_buf = priv->spi_transfer_buf + 4;
u8 *tx_buf = priv->spi_transfer_buf;
- struct spi_transfer t = {
+ struct spi_transfer tx = {
.tx_buf = tx_buf,
+ .len = SPI_OPLEN,
+ };
+ struct spi_transfer rx = {
.rx_buf = rx_buf,
- .len = SPI_OPLEN + len,
+ .len = len,
};
struct spi_message msg;
int ret;
tx_buf[0] = ENC28J60_READ_BUF_MEM;
- tx_buf[1] = tx_buf[2] = tx_buf[3] = 0; /* don't care */
spi_message_init(&msg);
- spi_message_add_tail(&t, &msg);
+ spi_message_add_tail(&tx, &msg);
+ spi_message_add_tail(&rx, &msg);
+
ret = spi_sync(priv->spi, &msg);
if (ret == 0) {
- memcpy(data, &rx_buf[SPI_OPLEN], len);
+ memcpy(data, rx_buf, len);
ret = msg.status;
}
if (ret && netif_msg_drv(priv))