Hi,
On 10/06/19 9:55 PM, Sergei Shtylyov wrote:
> Hello!
>
> On 06/09/2019 01:32 PM, Vignesh Raghavendra wrote:
>
>> Add binding documentation for TI's HyperBus memory controller present on
>> AM654 SoC.
>>
>> Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx>
>> ---
>> v5:
>> Update binding example to show MMIO mux
>> Fix reg property for flash slave.
>>
>> .../devicetree/bindings/mtd/ti,am654-hbmc.txt | 51 +++++++++++++++++++
>> MAINTAINERS | 1 +
>> 2 files changed, 52 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
>>
>> diff --git a/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt b/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
>> new file mode 100644
>> index 000000000000..c2a2c2b42a92
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
>> @@ -0,0 +1,51 @@
>> +Bindings for HyperBus Memory Controller (HBMC) on TI's K3 family of SoCs
>> +
>> +Required properties:
>> +- compatible : "ti,am654-hbmc" for AM654 SoC
>> +- reg : Two entries:
>> + First entry pointed to the register space of HBMC controller
>> + Second entry pointing to the memory map region dedicated for
>> + MMIO access to attached flash devices
>> +- ranges : Address translation from offset within CS to allocated MMIO
>> + space in SoC
>> +
>> +Optional properties:
>> +- mux-controls : phandle to the multiplexer that controls selection of
>> + HBMC vs OSPI inside Flash SubSystem. Default is OSPI,
>> + if property is absent.
>> + See Documentation/devicetree/bindings/mux/reg-mux.txt
>> + for mmio-mux binding details
>> +
>> +Example:
>> +
>> + fss: fss@47000000 {
>
> What's FSS?
Flash SubSystem (FSS). Will highlight that in mux control definition above
> Regardless of the answer, the node names should be generic, like "memory-controller@".
>
>> + compatible = "syscon", "simple-mfd";
>
> If it's "sycon", the nme should probably be "system-controller".
FSS is like a subchip that has all Flash controllers like Octal SPI
controllers and HyperBus controller within it. Some of their controls
are in the below address range. So I think its more closer to
"system-controller"
>
>> + reg = <0x0 0x47000000 0x0 0x100>;
>> + #address-cells = <2>;
>> + #size-cells = <2>;
>> + ranges;
>> +
>> + hbmc_mux: hbmc-mux {
>
> So, just "multiplexor"?
Ok
>
>> + compatible = "mmio-mux";
>> + #mux-control-cells = <1>;
>> + mux-reg-masks = <0x4 0x2>; /* 0: reg 0x4, bit 1 */
>> + };
>> +
>> + hbmc: hbmc@47034000 {
>
> Should be named "memory-controller@47034000", according to the DT spec.
IMO, since HyperBus is a bus protocol and has a specification, I think
its should have a separate generic name like SPI etc.
I will change this to "hyperbus@47034000" to common name of spec.
>
>> + compatible = "ti,am654-hbmc";
>> + reg = <0x0 0x47034000 0x0 0x100>,
>> + <0x5 0x00000000 0x1 0x0000000>;
>> + power-domains = <&k3_pds 55>;
>> + #address-cells = <2>;
>> + #size-cells = <1>;
>> + ranges = <0x0 0x0 0x5 0x00000000 0x4000000>, /* CS0 - 64MB */
>> + <0x1 0x0 0x5 0x04000000 0x4000000>; /* CS1 - 64MB */
>> + mux-controls = <&hbmc_mux 0>;
>> +
>> + /* Slave flash node */
>> + flash@0,0 {
>> + compatible = "cypress,hyperflash", "cfi-flash";
>> + reg = <0x0 0x0 0x4000000>;
>> + };
>> + };
>> + };
> [...]
>
> MBR, Sergei
>
--
Regards
Vignesh
