On Wed, 12 Dec 2012 10:46:00 +0200, Felipe Balbi <[email protected]> wrote: > there are a few spi master drivers which make > use of that flag but there is no way to pass it > through devicetree. > > This patch just creates a way to pass SPI_LOOP > via devicetree.
I don't understand how this would be useful since loopback mode is really just a test feature. Is there any reason to do loopback for something other than test? I think it would be better to add a sysfs or debugfs property to manipulate the SPI_LOOP flag from userspace. What do you think? g. > > Signed-off-by: Felipe Balbi <[email protected]> > --- > Documentation/devicetree/bindings/spi/spi-bus.txt | 2 ++ > drivers/spi/spi.c | 2 ++ > 2 files changed, 4 insertions(+) > > diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt > b/Documentation/devicetree/bindings/spi/spi-bus.txt > index 296015e..1949586 100644 > --- a/Documentation/devicetree/bindings/spi/spi-bus.txt > +++ b/Documentation/devicetree/bindings/spi/spi-bus.txt > @@ -55,6 +55,8 @@ contain the following properties. > chip select active high > - spi-3wire - (optional) Empty property indicating device requires > 3-wire mode. > +- spi-loopback - (optional) Empty property indicating device requires > + loopback mode. > > If a gpio chipselect is used for the SPI slave the gpio number will be passed > via the cs_gpio > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > index 3f1b9ee..6bcdc03 100644 > --- a/drivers/spi/spi.c > +++ b/drivers/spi/spi.c > @@ -868,6 +868,8 @@ static void of_register_spi_devices(struct spi_master > *master) > spi->mode |= SPI_CS_HIGH; > if (of_find_property(nc, "spi-3wire", NULL)) > spi->mode |= SPI_3WIRE; > + if (of_find_property(nc, "spi-loopback", NULL)) > + spi->mode |= SPI_LOOP; > > /* Device speed */ > prop = of_get_property(nc, "spi-max-frequency", &len); > -- > 1.8.1.rc1.5.g7e0651a > -- Grant Likely, B.Sc, P.Eng. Secret Lab Technologies, Ltd. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
