diff options
| -rw-r--r-- | drivers/spi/spi-armada-3700.c | 85 |
1 files changed, 73 insertions, 12 deletions
diff --git a/drivers/spi/spi-armada-3700.c b/drivers/spi/spi-armada-3700.c index 97938c6d6267..fdc35dabcda2 100644 --- a/drivers/spi/spi-armada-3700.c +++ b/drivers/spi/spi-armada-3700.c @@ -413,15 +413,20 @@ static void a3700_spi_transfer_setup(struct spi_device *spi, struct spi_transfer *xfer) { struct a3700_spi *a3700_spi; - unsigned int byte_len; a3700_spi = spi_master_get_devdata(spi->master); a3700_spi_clock_set(a3700_spi, xfer->speed_hz); - byte_len = xfer->bits_per_word >> 3; + /* Use 4 bytes long transfers. Each transfer method has its way to deal + * with the remaining bytes for non 4-bytes aligned transfers. + */ + a3700_spi_bytelen_set(a3700_spi, 4); - a3700_spi_fifo_thres_set(a3700_spi, byte_len); + /* Initialize the working buffers */ + a3700_spi->tx_buf = xfer->tx_buf; + a3700_spi->rx_buf = xfer->rx_buf; + a3700_spi->buf_len = xfer->len; } static void a3700_spi_set_cs(struct spi_device *spi, bool enable) @@ -576,27 +581,26 @@ static int a3700_spi_prepare_message(struct spi_master *master, if (ret) return ret; - a3700_spi_bytelen_set(a3700_spi, 4); - a3700_spi_mode_set(a3700_spi, spi->mode); return 0; } -static int a3700_spi_transfer_one(struct spi_master *master, +static int a3700_spi_transfer_one_fifo(struct spi_master *master, struct spi_device *spi, struct spi_transfer *xfer) { struct a3700_spi *a3700_spi = spi_master_get_devdata(master); int ret = 0, timeout = A3700_SPI_TIMEOUT; - unsigned int nbits = 0; + unsigned int nbits = 0, byte_len; u32 val; - a3700_spi_transfer_setup(spi, xfer); + /* Make sure we use FIFO mode */ + a3700_spi_fifo_mode_set(a3700_spi, true); - a3700_spi->tx_buf = xfer->tx_buf; - a3700_spi->rx_buf = xfer->rx_buf; - a3700_spi->buf_len = xfer->len; + /* Configure FIFO thresholds */ + byte_len = xfer->bits_per_word >> 3; + a3700_spi_fifo_thres_set(a3700_spi, byte_len); if (xfer->tx_buf) nbits = xfer->tx_nbits; @@ -731,6 +735,64 @@ out: return ret; } +static int a3700_spi_transfer_one_full_duplex(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *xfer) +{ + struct a3700_spi *a3700_spi = spi_master_get_devdata(master); + u32 val_in, val_out; + + /* Disable FIFO mode */ + a3700_spi_fifo_mode_set(a3700_spi, false); + + while (a3700_spi->buf_len) { + + /* When we have less than 4 bytes to transfer, switch to 1 byte + * mode. This is reset after each transfer + */ + if (a3700_spi->buf_len < 4) + a3700_spi_bytelen_set(a3700_spi, 1); + + if (a3700_spi->byte_len == 1) + val_out = *a3700_spi->tx_buf; + else + val_out = cpu_to_le32(*(u32 *)a3700_spi->tx_buf); + + spireg_write(a3700_spi, A3700_SPI_DATA_OUT_REG, val_out); + + /* Wait for all the data to be shifted in / out */ + while (!(spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG) & + A3700_SPI_XFER_DONE)) + cpu_relax(); + + val_in = le32_to_cpu(spireg_read(a3700_spi, + A3700_SPI_DATA_IN_REG)); + + memcpy(a3700_spi->rx_buf, &val_in, a3700_spi->byte_len); + + a3700_spi->buf_len -= a3700_spi->byte_len; + a3700_spi->tx_buf += a3700_spi->byte_len; + a3700_spi->rx_buf += a3700_spi->byte_len; + + } + + spi_finalize_current_transfer(master); + + return 0; +} + +static int a3700_spi_transfer_one(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *xfer) +{ + a3700_spi_transfer_setup(spi, xfer); + + if (xfer->tx_buf && xfer->rx_buf) + return a3700_spi_transfer_one_full_duplex(master, spi, xfer); + + return a3700_spi_transfer_one_fifo(master, spi, xfer); +} + static int a3700_spi_unprepare_message(struct spi_master *master, struct spi_message *message) { @@ -780,7 +842,6 @@ static int a3700_spi_probe(struct platform_device *pdev) master->transfer_one = a3700_spi_transfer_one; master->unprepare_message = a3700_spi_unprepare_message; master->set_cs = a3700_spi_set_cs; - master->flags = SPI_MASTER_HALF_DUPLEX; master->mode_bits |= (SPI_RX_DUAL | SPI_TX_DUAL | SPI_RX_QUAD | SPI_TX_QUAD); |