Re: [PATCH 3/4] Documentation: dt: Add bindings for Davinci DSP processors

[Suman Anna]

Hi Rob,

On 05/31/2017 02:22 PM, Rob Herring wrote:
> On Fri, May 26, 2017 at 03:21:39PM -0500, Suman Anna wrote:
>> Add the device tree bindings document for the DSP processor
>> subsystem devices on TI Davinci DA8xx/OMAP-L13x SoCs.
> 
> "dt-bindings: remoteproc:  ..." for the subject.

Ok, will fix this on v2

> 
>>
>> Signed-off-by: Suman Anna <s-anna@xxxxxx>
>> ---
>>  .../bindings/remoteproc/ti,davinci-rproc.txt       | 92 ++++++++++++++++++++++
>>  1 file changed, 92 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,davinci-rproc.txt
>>
>> diff --git a/Documentation/devicetree/bindings/remoteproc/ti,davinci-rproc.txt b/Documentation/devicetree/bindings/remoteproc/ti,davinci-rproc.txt
>> new file mode 100644
>> index 000000000000..e53572e22002
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/remoteproc/ti,davinci-rproc.txt
>> @@ -0,0 +1,92 @@
>> +TI Davinci DSP devices
>> +=======================
>> +
>> +Binding status: Unstable - Subject to changes for DT clocks and resets
> 
> Sorry, understandable if you didn't have documentation, but you work for 
> TI, figure out what the clocks and resets are.

Well, what I meant here is that the clocks and resets do not have a DT
representation yet on these SoCs. And when they do have a DT
representation, I would need to add the additional _required_ clocks and
resets properties, hence the marking.

> 
>> +
>> +The TI Davinci family of SoCs usually contains a TI DSP Core sub-system that
>> +is used to offload some of the processor-intensive tasks or algorithms, for
>> +achieving various system level goals.
>> +
>> +The processor cores in the sub-system usually contain additional sub-modules
>> +like L1 and/or L2 caches/SRAMs, an Interrupt Controller, an external memory
>> +controller, a dedicated local power/sleep controller etc. The DSP processor
>> +core used in Davinci SoCs is usually a C674x DSP CPU.
> 
> I'm wondering if your compatible string is specific enough with this 
> statement.

We always have integration aspects around these IPs into different SoCs,
so the compatible is following the SoC name. Also note that the C674x is
just the DSP core - one part of the DSP subsystem.

> 
>> +
>> +DSP Device Node:
>> +================
>> +Each DSP Core sub-system is represented as a single DT node.
>> +
>> +Required properties:
>> +--------------------
>> +The following are the mandatory properties:
>> +
>> +- compatible:		Should be one of the following,
>> +			    "ti,da850-dsp" for DSPs on OMAP-L138 SoCs
>> +
>> +- reg:			Should contain an entry for each value in 'reg-names'.
>> +			Each entry should have the memory region's start address
>> +			and the size of the region, the representation matching
>> +			the parent node's '#address-cells' and '#size-cells' values.
>> +
>> +- reg-names:		Should contain strings with the following names, each
>> +			representing a specific internal memory region or a
>> +			specific register space,
>> +			     "l2sram", "l1pram", "l1dram", "host1cfg", "chipsig_base"
>> +
>> +- interrupts: 		Should contain the interrupt number used to receive the
>> +			interrupts from the DSP. The value should follow the
>> +			interrupt-specifier format as dictated by the
>> +			'interrupt-parent' node.
>> +
>> +- memory-region:	phandle to the reserved memory node to be associated
>> +			with the remoteproc device. The reserved memory node
>> +			can be a CMA memory node, and should be defined as
>> +			per the bindings in
>> +			Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
>> +
>> +Optional properties:
>> +--------------------
>> +- interrupt-parent:	phandle to the interrupt controller node. This property
>> +			is needed if the device node hierarchy doesn't have an
>> +			interrupt controller.
>> +
>> +
>> +Example:
>> +--------
>> +
>> +	/* DA850 DTS file */
> 
> Don't show the dts split in examples.
> 
>> +	{
>> +		dsp: dsp@11800000 {
>> +			compatible = "ti,da850-dsp";
>> +			reg = <0x11800000 0x40000>,
>> +			      <0x11e00000 0x8000>,
>> +			      <0x11f00000 0x8000>,
>> +			      <0x01c14044 0x4>,
>> +			      <0x01c14174 0x8>;
>> +			reg-names = "l2sram", "l1pram", "l1dram", "host1cfg",
>> +				    "chipsig";
>> +			interrupt-parent = <&intc>;
>> +			interrupts = <28>;
>> +			status = "disabled";
> 
> Don't show status in examples.
> 
>> +		};
>> +
>> +	};
>> +
>> +	/* OMAP-L138 LCDK Board file */
>> +	reserved-memory {
>> +		#address-cells = <1>;
>> +		#size-cells = <1>;
>> +		ranges;
>> +
>> +		dsp_cma_pool: dsp_cma@c3000000 {
> 
> cma is a linuxism. dsp-memory@...

OK will fix up all these comments as well.

regards
Suman

> 
>> +                        compatible = "shared-dma-pool";
>> +                        reg = <0xc3000000 0x1000000>;
>> +                        reusable;
>> +                        status = "okay";
>> +                };
>> +	};
>> +
>> +	&dsp {
>> +		status = "okay";
>> +		memory-region = <&dsp_cma_pool>;
>> +	};
>> -- 
>> 2.12.0
>>