Hello Ahmad,
On Sat, Jul 30, 2022 at 11:10:34AM +0200, Ahmad Fatoum wrote:
> Hello Oleksij,
>
> On 13.04.22 10:22, Oleksij Rempel wrote:
> > +static int microchip_switch_probe(struct device_d *dev)
> > +{
> > + struct ksz_switch *priv;
> > + int ret = 0, gpio;
> > + struct dsa_switch *ds;
> > +
> > + priv = xzalloc(sizeof(*priv));
> > +
> > + dev->priv = priv;
> > + priv->dev = dev;
> > +
> > + priv->spi = (struct spi_device *)dev->type_data;
> > + priv->spi->mode = SPI_MODE_0;
>
> The kernel DSA driver configures SPI_MODE_3.
> Is it intended that you configure the barebox driver differently?
Yes. I wonted to investigate it deeper but didn't found time.
According to the KSZ9477S data sheet, SPI TIMING diagram:
we have following pictures:
FIGURE 6-9: SPI DATA INPUT TIMING
CLK ____/---\__/---\__/---\__/---\__/---\__
SDI {-----}{-----}{-----}{-----}{-----}
This is CPOL=0 and CPHA=0 == SPI_MODE_0
And FIGURE 6-10: SPI DATA OUTPUT TIMING
CLK ____/---\__/---\__/---\__/---\__/---\__
SDO {-----}{-----}{-----}{-----}{-----}
(LOW-SPEED MODE) This is CPOL=0 and CPHA=0 == SPI_MODE_0
SDO {-----}{-----}{-----}{-----}{-----}
(HIGH-SPEED MODE) This is CPOL=0 and CPHA=1 == SPI_MODE_1
If I see it correctly SPI_MODE_3 is not documented at all. And
SPI_MODE_3 didn't worked for me, this is why I started investigating it
:)
Regards,
Oleksij
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
