| Message ID | 1355301960-21523-2-git-send-email-balbi@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 12 Dec 2012 10:46:00 +0200, Felipe Balbi <balbi@ti.com> 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 <balbi@ti.com> > --- > 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 >
On Sat, Dec 15, 2012 at 12:32:24AM +0000, Grant Likely wrote: > On Wed, 12 Dec 2012 10:46:00 +0200, Felipe Balbi <balbi@ti.com> 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? might be nicer in the long run, indeed. Want me to look into it, or do you wanna do it yourself ?
On Sat, 15 Dec 2012 16:55:46 +0200, Felipe Balbi <balbi@ti.com> wrote: > On Sat, Dec 15, 2012 at 12:32:24AM +0000, Grant Likely wrote: > > On Wed, 12 Dec 2012 10:46:00 +0200, Felipe Balbi <balbi@ti.com> 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? > > might be nicer in the long run, indeed. Want me to look into it, or do > you wanna do it yourself ? Yes, please look into it. After all, you're the one who needs the feature/ :-) g. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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);
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. Signed-off-by: Felipe Balbi <balbi@ti.com> --- Documentation/devicetree/bindings/spi/spi-bus.txt | 2 ++ drivers/spi/spi.c | 2 ++ 2 files changed, 4 insertions(+)