On Thu, Aug 20, 2015 at 11:08 PM, Maxime Ripard <maxime.rip...@free-electrons.com> wrote: > Hi, > > Thanks a lot for working on this. > > On Wed, Aug 19, 2015 at 12:20:02PM +0800, Chen-Yu Tsai wrote: >> Reduced Serial Bus is a proprietary 2-line push-pull serial bus >> supporting multiple slave devices. >> >> It was developed by Allwinner, Inc. and used by Allwinner and X-Powers, >> Inc. for their line of PMICs and other peripheral ICs. >> >> Signed-off-by: Chen-Yu Tsai <w...@csie.org> >> --- >> Documentation/devicetree/bindings/rsb/rsb.txt | 50 >> +++++++++++++++++++++++++++ >> 1 file changed, 50 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/rsb/rsb.txt >> >> diff --git a/Documentation/devicetree/bindings/rsb/rsb.txt >> b/Documentation/devicetree/bindings/rsb/rsb.txt >> new file mode 100644 >> index 000000000000..0b027948ca9c >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/rsb/rsb.txt >> @@ -0,0 +1,50 @@ >> +Reduced Serial Bus (RSB) Controller >> + >> +This document defines a generic set of bindings for use by RSB controllers. >> +A controller is modelled in device tree as a node with zero or more child >> +nodes, each representing a unique slave device on the bus. >> + >> +Required properties: >> + >> + - #address-cells : must be 2 >> + - #size-cells : must be 0 >> + >> +Optional properties: >> + >> + - clock-frequency : Desired bus clock frequency in Hz. Maximum is 20 MHz. > > What is the default if not set?
Presently the driver would have it default to 1 MHz, Which doesn't match the driver binding. Will fix this. >> + >> +Child nodes: >> + >> +An RSB controller node can contain zero or more child nodes representing >> +slave devices on the bus. Child 'reg' properties are specified as a >> +runtime address, hardware address pair. The hardware address is hardwired >> +in the device, which can normally be found in the datasheet. The runtime >> +address is set by software. No 2 devices on the same bus shall have the >> +same runtime address. >> + >> +Valid runtime addresses - There are only 15 valid runtime addresses: >> + >> + 0x17, 0x2d, 0x3a, 0x4e, 0x59, 0x63, 0x74, 0x8b, >> + 0x9c, 0xa6, 0xb1, 0xc5, 0xd2, 0xe8, 0xff >> + >> +It is highly recommended that one choose the same runtime addresses as >> +vendor BSPs use so that a) the addresses remain the same across different >> +software systems, and b) addresses of supported and listed slave devices >> +don't conflict with unsupported or not yet listed devices. > > I'd expect to have the hardware address first, but maybe it's just me > :) I don't know. It's only used at init time. And in my latest experience, once the runtime address is set by the bootloader, it can't be changed. My earlier experience was the opposite, though I haven't figured out why. > >> +Example: >> + >> + rsb@... { >> + compatible = "..."; >> + reg = <...>; >> + /* ... */ >> + #address-cells = <2>; >> + #size-cells = <0>; >> + >> + pmic@2d { > > The unit-address should be 2d,3e3. Hmm... I didn't know this was legal. >> + compatible = "..."; >> + reg = <0x2d 0x3e3>; >> + >> + /* ... */ >> + }; >> + }; >> -- >> 2.5.0 >> > > -- > Maxime Ripard, Free Electrons > Embedded Linux, Kernel and Android engineering > http://free-electrons.com -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.