On Mon, Jan 30, 2012 at 04:27:49PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote: > This will allow to use gpio for chip select with no modification in the > driver binding > > When use the ncs-gpio, the gpio number will be passed via the controller_data > and the number of chip select will automatically increased. > > When a spi master have only gpio chip select and is probe via dt check the > number of chip select only when adding slave. > > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagn...@jcrosoft.com> > Cc: devicetree-disc...@lists.ozlabs.org > Cc: spi-devel-general@lists.sourceforge.net > --- > Documentation/devicetree/bindings/spi/spi-bus.txt | 9 ++++++- > drivers/of/of_spi.c | 27 ++++++++++++++------ > drivers/spi/spi.c | 2 +- > 3 files changed, 28 insertions(+), 10 deletions(-) > > diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt > b/Documentation/devicetree/bindings/spi/spi-bus.txt > index e782add..1dccf35 100644 > --- a/Documentation/devicetree/bindings/spi/spi-bus.txt > +++ b/Documentation/devicetree/bindings/spi/spi-bus.txt > @@ -21,9 +21,16 @@ assumption that board specific platform code will be used > to manage > chip selects. Individual drivers can define additional properties to > support describing the chip select layout. > > +If a gpio a specified to the SPI slave and no hardware chip select is present > +the reg property #address-cells and #size-cells are not needed. > + > +When use the ncs-gpio the gpio number will be passed via the controller_data > +and the number of chip select will automatically increased. > + > SPI slave nodes must be children of the SPI master node and can > contain the following properties. > -- reg - (required) chip select address of device. > +- reg - (required if no ncs-gpio) chip select address of device. > +- ncs-gpio - (required if no reg) chip select gpio of device.
There is already precedence for using gpios for chip selects. The slave device nodes remain as they are and it is the responsibility of the spi bus node to have a gpios property with a list of SS gpios. The order of the gpios property should match the 'reg' address numbering of the child node. I don't like the idea of having multiple bindings for the slave address of the spi device (reg or ncs-gpio) What I want to see is generic SS helper code that spi bus drivers default to and correctly implement parsing of chip select gpios. I'm not going to apply this patch. g. ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
