RE: [PATCH 1/4] spi: add support for octal I/O data transfer

[Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx>]

Hi Boris,

> -----Original Message-----
> From: Boris Brezillon [mailto:boris.brezillon@xxxxxxxxxxx]
> Sent: Thursday, October 4, 2018 2:35 PM
> To: Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx>
> Cc: linux-mtd@xxxxxxxxxxxxxxxxxxx; marek.vasut@xxxxxxxxx; vigneshr@xxxxxx;
> linux-spi@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; robh@xxxxxxxxxx;
> mark.rutland@xxxxxxx; shawnguo@xxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; computersforpeace@xxxxxxxxx;
> frieder.schrempf@xxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH 1/4] spi: add support for octal I/O data transfer
> 
> Hi Yogesh,
> 
> On Thu,  4 Oct 2018 14:18:37 +0530
> Yogesh Gaur <yogeshnarayan.gaur@xxxxxxx> wrote:
> 
> > Add flags for Octal I/O data transfer
> > Required for the SPI controller which can do the data transfer (TX/RX)
> > on 8 data lines e.g. NXP FlexSPI controller.
> >  SPI_TX_OCTAL: transmit with 8 wires
> >  SPI_RX_OCTAL: receive with 8 wires
> >
> > Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur@xxxxxxx>
> > ---
> >  drivers/spi/spi.c       | 6 ++++++
> >  include/linux/spi/spi.h | 2 ++
> >  2 files changed, 8 insertions(+)
> >
> > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index
> > ec395a6..80f672f 100644
> > --- a/drivers/spi/spi.c
> > +++ b/drivers/spi/spi.c
> > @@ -1573,6 +1573,9 @@ static int of_spi_parse_dt(struct spi_controller *ctlr,
> struct spi_device *spi,
> >  		case 4:
> >  			spi->mode |= SPI_TX_QUAD;
> >  			break;
> > +		case 8:
> > +			spi->mode |= SPI_TX_OCTAL;
> > +			break;
> >  		default:
> >  			dev_warn(&ctlr->dev,
> >  				"spi-tx-bus-width %d not supported\n", @@ -
> 1591,6 +1594,9 @@
> > static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
> >  		case 4:
> >  			spi->mode |= SPI_RX_QUAD;
> >  			break;
> > +		case 8:
> > +			spi->mode |= SPI_RX_OCTAL;
> > +			break;
> >  		default:
> >  			dev_warn(&ctlr->dev,
> >  				"spi-rx-bus-width %d not supported\n", diff --
> git
> > a/include/linux/spi/spi.h b/include/linux/spi/spi.h index
> > a64235e..2d21307 100644
> > --- a/include/linux/spi/spi.h
> > +++ b/include/linux/spi/spi.h
> > @@ -163,6 +163,8 @@ struct spi_device {
> >  #define	SPI_TX_QUAD	0x200			/* transmit with 4
> wires */
> >  #define	SPI_RX_DUAL	0x400			/* receive with 2 wires
> */
> >  #define	SPI_RX_QUAD	0x800			/* receive with 4 wires
> */
> > +#define	SPI_TX_OCTAL	0x1000			/* transmit with 8
> wires */
> > +#define	SPI_RX_OCTAL	0x2000			/* receive with 8 wires
> */
> >  	int			irq;
> >  	void			*controller_state;
> >  	void			*controller_data;
> 
> You're still not updating spi-mem.c to check those flags and
> SPI_MEM_MAX_BUSWIDTH is not updated to match the new limit (8 instead of
> 4).
> 
Yes and its strange that my octal mode communication is working fine without adding support in spi-mem.c and that's why this has been missed from me.
For this patch series, have done data read/write verification using MTD_DEBUG and JFFS2 mount utility and none of them reports data read error.
Would add octal mode related changes in this file too.

--
Regards
Yogesh Gaur.

> Regards,
> 
> Boris

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