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authorSanchayan Maity <maitysanchayan@gmail.com>2016-11-22 10:01:31 +0300
committerMark Brown <broonie@kernel.org>2016-11-22 19:47:25 +0300
commitccf7d8ee3d6eb600338a184e9a192ec1d5aee924 (patch)
treeee3a4dbd2cbf0c9e12690d57de32097d6e3a8a34 /drivers/spi/spi-fsl-dspi.c
parent1eaccf210c59e04eb6e9b5469a60d6609c95ac61 (diff)
downloadlinux-ccf7d8ee3d6eb600338a184e9a192ec1d5aee924.tar.xz
spi: spi-fsl-dspi: Fix continuous selection format
Current DMA implementation was not handling the continuous selection format viz. SPI chip select would be deasserted even between sequential serial transfers. Use existing dspi_data_to_pushr function to restructure the transmit code path and set or reset the CONT bit on same lines as code path in EOQ mode does. This correctly implements continuous selection format while also correcting and cleaning up the transmit code path. Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-fsl-dspi.c')
-rw-r--r--drivers/spi/spi-fsl-dspi.c20
1 files changed, 6 insertions, 14 deletions
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index cb41c327bd77..7ada112bfd85 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -196,6 +196,8 @@ struct fsl_dspi {
struct fsl_dspi_dma *dma;
};
+static u32 dspi_data_to_pushr(struct fsl_dspi *dspi, int tx_word);
+
static inline int is_double_byte_mode(struct fsl_dspi *dspi)
{
unsigned int val;
@@ -242,24 +244,15 @@ static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi)
int time_left;
int tx_word;
int i;
- u16 val;
tx_word = is_double_byte_mode(dspi);
- for (i = 0; i < dma->curr_xfer_len - 1; i++) {
- val = tx_word ? *(u16 *) dspi->tx : *(u8 *) dspi->tx;
- dspi->dma->tx_dma_buf[i] =
- SPI_PUSHR_TXDATA(val) | SPI_PUSHR_PCS(dspi->cs) |
- SPI_PUSHR_CTAS(0) | SPI_PUSHR_CONT;
- dspi->tx += tx_word + 1;
+ for (i = 0; i < dma->curr_xfer_len; i++) {
+ dspi->dma->tx_dma_buf[i] = dspi_data_to_pushr(dspi, tx_word);
+ if ((dspi->cs_change) && (!dspi->len))
+ dspi->dma->tx_dma_buf[i] &= ~SPI_PUSHR_CONT;
}
- val = tx_word ? *(u16 *) dspi->tx : *(u8 *) dspi->tx;
- dspi->dma->tx_dma_buf[i] = SPI_PUSHR_TXDATA(val) |
- SPI_PUSHR_PCS(dspi->cs) |
- SPI_PUSHR_CTAS(0);
- dspi->tx += tx_word + 1;
-
dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx,
dma->tx_dma_phys,
dma->curr_xfer_len *
@@ -351,7 +344,6 @@ static int dspi_dma_xfer(struct fsl_dspi *dspi)
curr_remaining_bytes -= dma->curr_xfer_len * word;
if (curr_remaining_bytes < 0)
curr_remaining_bytes = 0;
- dspi->len = curr_remaining_bytes;
}
}