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

Yogesh Narayan Gaur
2018-10-04T09:14:36Z

Hi Boris,

> -----Original Message-----
> From: Boris Brezillon [mailto:boris.brezillon@bootlin.com]
> Sent: Thursday, October 4, 2018 2:35 PM
> To: Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com>
> Cc: linux-mtd@lists.infradead.org; marek.vasut@gmail.com; vigneshr@ti.com;
> linux-spi@vger.kernel.org; devicetree@vger.kernel.org; robh@kernel.org;
> mark.rutland@arm.com; shawnguo@kernel.org; linux-arm-
> kernel@lists.infradead.org; computersforpeace@gmail.com;
> frieder.schrempf@exceet.de; linux-kernel@vger.kernel.org
> 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@nxp.com> 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@nxp.com>
> > ---
> > 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