RE: [PATCH 2/2] spi: spi-fsl-dspi: Fix support for XSPI transport mode

[Chuanhua Han]

> -----Original Message-----
> From: Chuanhua Han <chuanhua.han@xxxxxxx>
> Sent: 2018年9月21日 15:06
> To: broonie@xxxxxxxxxx
> Cc: linux-spi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; eha@xxxxxxxx;
> boris.brezillon@xxxxxxxxxxx; Chuanhua Han <chuanhua.han@xxxxxxx>
> Subject: [PATCH 2/2] spi: spi-fsl-dspi: Fix support for XSPI transport mode
> 
> This patch fixes the problem that the XSPI mode of the dspi controller cannot
> transfer data properly.
> In XSPI mode, cmd_fifo is written before tx_fifo, which transforms the byte
> order of sending and receiving data.
> 
> Signed-off-by: Chuanhua Han <chuanhua.han@xxxxxxx>
> ---
>  drivers/spi/spi-fsl-dspi.c | 29 +++++++++++++++++++----------
>  1 file changed, 19 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index
> 3082e72e4f6c..44cc2bd0120e 100644
> --- a/drivers/spi/spi-fsl-dspi.c
> +++ b/drivers/spi/spi-fsl-dspi.c
> @@ -220,9 +220,15 @@ static u32 dspi_pop_tx(struct fsl_dspi *dspi)
>  		if (dspi->bytes_per_word == 1)
>  			txdata = *(u8 *)dspi->tx;
>  		else if (dspi->bytes_per_word == 2)
> -			txdata = *(u16 *)dspi->tx;
> +			if (dspi->cur_chip->ctar_val & SPI_CTAR_LSBFE(1))
> +				txdata =  cpu_to_le16(*(u16 *)dspi->tx);
> +			else
> +				txdata =  cpu_to_be16(*(u16 *)dspi->tx);
>  		else  /* dspi->bytes_per_word == 4 */
> -			txdata = *(u32 *)dspi->tx;
> +			if (dspi->cur_chip->ctar_val & SPI_CTAR_LSBFE(1))
> +				txdata = cpu_to_le32(*(u32 *)dspi->tx);
> +			else
> +				txdata = cpu_to_be32(*(u32 *)dspi->tx);
>  		dspi->tx += dspi->bytes_per_word;
>  	}
>  	dspi->len -= dspi->bytes_per_word;
> @@ -243,15 +249,18 @@ static void dspi_push_rx(struct fsl_dspi *dspi, u32
> rxdata)
>  	if (!dspi->rx)
>  		return;
> 
> -	/* Mask of undefined bits */
> -	rxdata &= (1 << dspi->bits_per_word) - 1;
> -
>  	if (dspi->bytes_per_word == 1)
>  		*(u8 *)dspi->rx = rxdata;
>  	else if (dspi->bytes_per_word == 2)
> -		*(u16 *)dspi->rx = rxdata;
> +		if (dspi->cur_chip->ctar_val & SPI_CTAR_LSBFE(1))
> +			*(u16 *)dspi->rx = be16_to_cpu(rxdata);
> +		else
> +			*(u16 *)dspi->rx = be16_to_cpu(rxdata);
>  	else /* dspi->bytes_per_word == 4 */
> -		*(u32 *)dspi->rx = rxdata;
> +		if (dspi->cur_chip->ctar_val & SPI_CTAR_LSBFE(1))
> +			*(u32 *)dspi->rx = le32_to_cpu(rxdata);
> +		else
> +			*(u32 *)dspi->rx = be32_to_cpu(rxdata);
>  	dspi->rx += dspi->bytes_per_word;
>  }
> 
> @@ -593,16 +602,16 @@ static void dspi_tcfq_write(struct fsl_dspi *dspi)
>  		 */
>  		u32 data = dspi_pop_tx(dspi);
> 
> +		cmd_fifo_write(dspi);
>  		if (dspi->cur_chip->ctar_val & SPI_CTAR_LSBFE(1)) {
>  			/* LSB */
> -			tx_fifo_write(dspi, data & 0xFFFF);
>  			tx_fifo_write(dspi, data >> 16);
> +			tx_fifo_write(dspi, data & 0xFFFF);
>  		} else {
>  			/* MSB */
> -			tx_fifo_write(dspi, data >> 16);
>  			tx_fifo_write(dspi, data & 0xFFFF);
> +			tx_fifo_write(dspi, data >> 16);
>  		}
> -		cmd_fifo_write(dspi);
>  	} else {
>  		/* Write one entry to both TX FIFO and CMD FIFO
>  		 * simultaneously.
> --
> 2.17.1
Hi,all
Could you please help me to see the fix of this patch? What changes need to be made? 
Looking forward to your valuable comments and criticism, thank you very much!!!
Thanks,
Chuanhua