On 11/10/2014 05:22 PM, Andrew Bresticker wrote: > Hi Ezequiel, James, > > On Mon, Nov 10, 2014 at 11:30 AM, Ezequiel Garcia > <ezequiel.garcia@xxxxxxxxxx> wrote: >> From: James Hogan <james.hogan@xxxxxxxxxx> >> >> Introduce a devicetree binding for Imagination Technologies >> I2C SCB controller. >> >> Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx> >> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@xxxxxxxxxx> > >> diff --git a/Documentation/devicetree/bindings/i2c/i2c-img-scb.txt b/Documentation/devicetree/bindings/i2c/i2c-img-scb.txt >> new file mode 100644 >> index 0000000..3a5cd1f >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/i2c/i2c-img-scb.txt >> @@ -0,0 +1,29 @@ >> +IMG Serial Control Bus (SCB) I2C Controller >> + >> +Required Properties: >> +- compatible: "img,scb-i2c" >> +- reg: Physical base address and length of controller registers >> +- interrupts: Interrupt number used by the controller >> +- clocks : Should contain a clock specifier for each entry in clock-names >> +- clock-names : Should contain the following entries: >> + "scb", for the SCB core clock. >> + "sys", for the system clock. >> +- clock-frequency: The I2C bus frequency in Hz >> +- #address-cells: Should be <1> >> +- #size-cells: Should be <0> >> + >> +Optional Properties >> +- img,bus-delay : Bus delay in ms, defaults to 0. > > Maybe this is a dumb question, but what delay does this correspond to > in hardware? In what situations would we use a non-zero value? > I'm not sure when would we need a non-zero value. The TRM I have here mentions the bus delay parameter models the delay in the internal Clock Enable Generation block, and which affects the values that should be written to obtain a specified clock enable rate. After re-reading the code that configures the clock generation, I think we can use some more comments :) -- Ezequiel -- 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
