Re: [PATCH 3/4] spi: spi-fsl-dspi: Fix continuous selection format

[maitysanchayan]

Hello Stefan,

On 16-11-17 17:07:24, Stefan Agner wrote:
> 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 
> > ---
> >  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...

Agreed. It's much better. Should be !dspi->cs_change though.

Will include it in next iteration.

Thanks & Regards,
Sanchayan.

> 
> --
> Stefan
> 
> 
> 
> > dspi->tx += tx_word + 1;
> >  
> > dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx,

Re: [PATCH 3/4] spi: spi-fsl-dspi: Fix continuous selection format

[maitysanchayan]

Hello Stefan,

On 16-11-17 17:07:24, Stefan Agner wrote:
> 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 
> > ---
> >  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...

Agreed. It's much better. Should be !dspi->cs_change though.

Will include it in next iteration.

Thanks & Regards,
Sanchayan.

> 
> --
> Stefan
> 
> 
> 
> > dspi->tx += tx_word + 1;
> >  
> > dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx,

Re: [PATCH 3/4] spi: spi-fsl-dspi: Fix continuous selection format

[Stefan Agner]

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 
> ---
>  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,

Re: [PATCH 3/4] spi: spi-fsl-dspi: Fix continuous selection format

[Stefan Agner]

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 
> ---
>  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,

[PATCH 3/4] spi: spi-fsl-dspi: Fix continuous selection format

[Sanchayan Maity]

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 
---
 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;
+   }
dspi->tx += tx_word + 1;
 
dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx,
-- 
2.10.2

[PATCH 3/4] spi: spi-fsl-dspi: Fix continuous selection format

[Sanchayan Maity]

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 
---
 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;
+   }
dspi->tx += tx_word + 1;
 
dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx,
-- 
2.10.2