Messages in this thread | | | Date | Thu, 17 Nov 2016 17:07:24 -0800 | From | Stefan Agner <> | Subject | Re: [PATCH 3/4] spi: spi-fsl-dspi: Fix continuous selection format |
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On 2016-11-17 04:16, Sanchayan Maity wrote: > Current DMA implementation was not handling the continuous selection > format viz. SPI chip select would be deasserted even between sequential > serial transfers. Use the cs_change variable and correctly set or > reset the CONT bit accordingly for case where peripherals require > the chip select to be asserted between sequential transfers. > > Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com> > --- > drivers/spi/spi-fsl-dspi.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c > index aee8c88..164e2e1 100644 > --- a/drivers/spi/spi-fsl-dspi.c > +++ b/drivers/spi/spi-fsl-dspi.c > @@ -258,9 +258,16 @@ static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi) > } > > 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); > + if (dspi->cs_change) { > + dspi->dma->tx_dma_buf[i] = SPI_PUSHR_TXDATA(val) | > + SPI_PUSHR_PCS(dspi->cs) | > + SPI_PUSHR_CTAS(0); > + } else { > + dspi->dma->tx_dma_buf[i] = SPI_PUSHR_TXDATA(val) | > + SPI_PUSHR_PCS(dspi->cs) | > + SPI_PUSHR_CTAS(0) | > + SPI_PUSHR_CONT; > + }
How about:
dspi->dma->tx_dma_buf[i] = SPI_PUSHR_TXDATA(val) | SPI_PUSHR_PCS(dspi->cs) | SPI_PUSHR_CTAS(0);
+ if (dspi->cs_change) + dspi->dma->tx_dma_buf[i] |= SPI_PUSHR_CONT;
Avoids code duplication...
-- Stefan
> dspi->tx += tx_word + 1; > > dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx,
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