On Fri, Jun 20, 2014 at 02:18:31PM +0100, Geert Uytterhoeven wrote: > Hi Mark, > > On Fri, Jun 20, 2014 at 2:52 PM, Mark Rutland <[email protected]> wrote: > > On Fri, Jun 20, 2014 at 11:20:37AM +0100, Geert Uytterhoeven wrote: > >> Signed-off-by: Geert Uytterhoeven <[email protected]> > >> --- > >> The format of the DMA specifiers depends on the DT bindings for SHDMA, > >> which are still under development. > >> > >> Documentation/devicetree/bindings/spi/sh-msiof.txt | 17 +++++++++++++-- > >> drivers/spi/spi-sh-msiof.c | 25 > >> ++++++++++++++++------ > >> 2 files changed, 33 insertions(+), 9 deletions(-) > >> > >> diff --git a/Documentation/devicetree/bindings/spi/sh-msiof.txt > >> b/Documentation/devicetree/bindings/spi/sh-msiof.txt > >> index f24baf3b6cc1..fc56e312c0bc 100644 > >> --- a/Documentation/devicetree/bindings/spi/sh-msiof.txt > >> +++ b/Documentation/devicetree/bindings/spi/sh-msiof.txt > >> @@ -7,7 +7,13 @@ Required properties: > >> Examples with soctypes are: > >> "renesas,msiof-r8a7790" (R-Car H2) > >> "renesas,msiof-r8a7791" (R-Car M2) > >> -- reg : Offset and length of the register set for the > >> device > >> +- reg : A list of offsets and lengths of the register > >> sets for > >> + the device. > >> + If only one register set is present, it is to be > >> used > >> + by both the CPU and the DMA engine. > >> + If two register sets are present, the first is to be > >> + used by the CPU, and the second is to be used by the > >> + DMA engine. > > > > I'm missing something here. I'm we're providing the DMA engines through > > DMA specifiers below, then why do we need the DMA engine address here? > > Surely they're separate device nodes? > > It's not the DMA engine address, but the second bank of MSIOF addresses. > > The MSIOF has two (identical) sets of register banks: the first one is to > be accessed by the CPU, the second one (actually only the Transmit FIFO > and Receive FIFO Data Registers) is to be accessed by the DMA engine.
Ah, I see. Thanks for the clarification. > > The code update doesn't seem to do anything with the additional reg > > entry. > > Indeed, as the second bank of registers is already used by spi-sh-msiof.c > for the non-DT DMA case. Register banks are resources, so they're > already present in non-DT platform devices. Ok. That makes sense then. Cheers, Mark. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
