[PATCH] spi: imx: fix the burst length at DMA mode and CPU mode

[PATCH] spi: imx: fix the burst length at DMA mode and CPU mode

[carlos.song]

From: Carlos Song <carlos.song@nxp.com>

For DMA mode, the bus width of the DMA is equal to the size of data
word, so burst length should be configured as bits per word.

For CPU mode, because of the spi transfer len is in byte, so burst
length should be configured as bits per byte * spi_imx->count.

Signed-off-by: Carlos Song <carlos.song@nxp.com>
Reviewed-by: Clark Wang <xiaoning.wang@nxp.com>
Fixes: e9b220aeacf1 ("spi: spi-imx: correctly configure burst length when using dma")
Fixes: 5f66db08cbd3 ("spi: imx: Take in account bits per word instead of assuming 8-bits")
---
 drivers/spi/spi-imx.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 546cdce525fc..b4ade2d53fef 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -54,7 +54,7 @@ MODULE_PARM_DESC(polling_limit_us,
 #define MX51_ECSPI_CTRL_MAX_BURST	512
 /* The maximum bytes that IMX53_ECSPI can transfer in target mode.*/
 #define MX53_MAX_TRANSFER_BYTES		512
-
+#define BITS_PER_BYTE	8
 enum spi_imx_devtype {
 	IMX1_CSPI,
 	IMX21_CSPI,
@@ -660,15 +660,14 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
 			<< MX51_ECSPI_CTRL_BL_OFFSET;
 	else {
 		if (spi_imx->usedma) {
-			ctrl |= (spi_imx->bits_per_word *
-				spi_imx_bytes_per_word(spi_imx->bits_per_word) - 1)
+			ctrl |= (spi_imx->bits_per_word - 1)
 				<< MX51_ECSPI_CTRL_BL_OFFSET;
 		} else {
 			if (spi_imx->count >= MX51_ECSPI_CTRL_MAX_BURST)
-				ctrl |= (MX51_ECSPI_CTRL_MAX_BURST - 1)
+				ctrl |= (MX51_ECSPI_CTRL_MAX_BURST * BITS_PER_BYTE - 1)
 						<< MX51_ECSPI_CTRL_BL_OFFSET;
 			else
-				ctrl |= (spi_imx->count * spi_imx->bits_per_word - 1)
+				ctrl |= (spi_imx->count * BITS_PER_BYTE - 1)
 						<< MX51_ECSPI_CTRL_BL_OFFSET;
 		}
 	}
-- 
2.34.1


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Re: [PATCH] spi: imx: fix the burst length at DMA mode and CPU mode

[Marc Kleine-Budde]

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On 31.01.2024 10:46:23, carlos.song@nxp.com wrote:
> From: Carlos Song <carlos.song@nxp.com>
> 
> For DMA mode, the bus width of the DMA is equal to the size of data
> word, so burst length should be configured as bits per word.
> 
> For CPU mode, because of the spi transfer len is in byte, so burst
> length should be configured as bits per byte * spi_imx->count.
> 
> Signed-off-by: Carlos Song <carlos.song@nxp.com>
> Reviewed-by: Clark Wang <xiaoning.wang@nxp.com>
> Fixes: e9b220aeacf1 ("spi: spi-imx: correctly configure burst length when using dma")
> Fixes: 5f66db08cbd3 ("spi: imx: Take in account bits per word instead of assuming 8-bits")
> ---
>  drivers/spi/spi-imx.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
> index 546cdce525fc..b4ade2d53fef 100644
> --- a/drivers/spi/spi-imx.c
> +++ b/drivers/spi/spi-imx.c
> @@ -54,7 +54,7 @@ MODULE_PARM_DESC(polling_limit_us,
>  #define MX51_ECSPI_CTRL_MAX_BURST	512
>  /* The maximum bytes that IMX53_ECSPI can transfer in target mode.*/
>  #define MX53_MAX_TRANSFER_BYTES		512
> -
> +#define BITS_PER_BYTE	8

That's already defined in linux/bits.h

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |

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Re: [PATCH] spi: imx: fix the burst length at DMA mode and CPU mode

[Carlos Song]

> -----Original Message-----
> From: Marc Kleine-Budde <mkl@pengutronix.de>
> Sent: Wednesday, January 31, 2024 4:08 PM
> To: Carlos Song <carlos.song@nxp.com>
> Cc: broonie@kernel.org; shawnguo@kernel.org; s.hauer@pengutronix.de;
> kernel@pengutronix.de; dl-linux-imx <linux-imx@nxp.com>; benjamin@bigler.one;
> stefanmoring@gmail.com; linux-kernel@vger.kernel.org;
> linux-arm-kernel@lists.infradead.org; linux-spi@vger.kernel.org
> Subject: [EXT] Re: [PATCH] spi: imx: fix the burst length at DMA mode and CPU
> mode
> 
> On 31.01.2024 10:46:23, carlos.song@nxp.com wrote:
> > From: Carlos Song <carlos.song@nxp.com>
> >
> > For DMA mode, the bus width of the DMA is equal to the size of data
> > word, so burst length should be configured as bits per word.
> >
> > For CPU mode, because of the spi transfer len is in byte, so burst
> > length should be configured as bits per byte * spi_imx->count.
> >
> > Signed-off-by: Carlos Song <carlos.song@nxp.com>
> > Reviewed-by: Clark Wang <xiaoning.wang@nxp.com>
> > Fixes: e9b220aeacf1 ("spi: spi-imx: correctly configure burst length
> > when using dma")
> > Fixes: 5f66db08cbd3 ("spi: imx: Take in account bits per word instead
> > of assuming 8-bits")
> > ---
> >  drivers/spi/spi-imx.c | 9 ++++-----
> >  1 file changed, 4 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index
> > 546cdce525fc..b4ade2d53fef 100644
> > --- a/drivers/spi/spi-imx.c
> > +++ b/drivers/spi/spi-imx.c
> > @@ -54,7 +54,7 @@ MODULE_PARM_DESC(polling_limit_us,
> >  #define MX51_ECSPI_CTRL_MAX_BURST	512
> >  /* The maximum bytes that IMX53_ECSPI can transfer in target mode.*/
> >  #define MX53_MAX_TRANSFER_BYTES		512
> > -
> > +#define BITS_PER_BYTE	8
> 

It will be removed and I will send patch V2.
Thank you!

BR
Carlos

> That's already defined in linux/bits.h
> 
> regards,
> Marc
> 
> --
> Pengutronix e.K.                 | Marc Kleine-Budde          |
> Embedded Linux                   | https://www.pengutronix.de |
> Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
> Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |
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Re: [PATCH] spi: imx: fix the burst length at DMA mode and CPU mode

[Francesco Dolcini]

On Wed, Jan 31, 2024 at 10:46:23AM +0800, carlos.song@nxp.com wrote:
> From: Carlos Song <carlos.song@nxp.com>
> 
> For DMA mode, the bus width of the DMA is equal to the size of data
> word, so burst length should be configured as bits per word.
> 
> For CPU mode, because of the spi transfer len is in byte, so burst
> length should be configured as bits per byte * spi_imx->count.
> 
> Signed-off-by: Carlos Song <carlos.song@nxp.com>
> Reviewed-by: Clark Wang <xiaoning.wang@nxp.com>
> Fixes: e9b220aeacf1 ("spi: spi-imx: correctly configure burst length when using dma")
> Fixes: 5f66db08cbd3 ("spi: imx: Take in account bits per word instead of assuming 8-bits")

Cc:stable...

> ---
>  drivers/spi/spi-imx.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
> index 546cdce525fc..b4ade2d53fef 100644
> --- a/drivers/spi/spi-imx.c
> +++ b/drivers/spi/spi-imx.c
> @@ -54,7 +54,7 @@ MODULE_PARM_DESC(polling_limit_us,
>  #define MX51_ECSPI_CTRL_MAX_BURST	512
>  /* The maximum bytes that IMX53_ECSPI can transfer in target mode.*/
>  #define MX53_MAX_TRANSFER_BYTES		512
> -
> +#define BITS_PER_BYTE	8

this is already defined in linux/bits.h, just use it from there.

Francesco


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