On Thu, Nov 19, 2015 at 04:53:42PM +0100, Marcus Weseloh wrote: > Adds support and documentation for a new slave device property > "sun4i,spi-wdelay" that allows to set the SPI Wait Clock Register per > device / transfer. The SPI hardware will wait the specified amount of > SPI clock periods (plus a constant 3 clock periods) before transmitting > the next word. > > The constant additional 3 clock periods are not documented by the vendor > and have been determined by analyzing the generated waveforms across > many different transmission speeds. > > Signed-off-by: Marcus Weseloh <mweseloh42@xxxxxxxxx> > --- > Documentation/devicetree/bindings/spi/spi-sun4i.txt | 11 +++++++++++ > drivers/spi/spi-sun4i.c | 7 +++++++ > 2 files changed, 18 insertions(+) > > diff --git a/Documentation/devicetree/bindings/spi/spi-sun4i.txt b/Documentation/devicetree/bindings/spi/spi-sun4i.txt > index de827f5..9c4d723 100644 > --- a/Documentation/devicetree/bindings/spi/spi-sun4i.txt > +++ b/Documentation/devicetree/bindings/spi/spi-sun4i.txt > @@ -10,6 +10,10 @@ Required properties: > - "mod": the parent module clock > - clock-names: Must contain the clock names described just above > > +Optional properties for slave devices: > +- sun4i,spi-wdelay : delay between transmission of words, specified in number > + of SPI clock periods (actual delay is wdelay + 3 clock periods) Seems like a common property to me. For a common one, it should be the actual delay and the driver needs to subtract the 3 clock periods here. Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
