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

From: Rob Herring
Date: Wed May 31 2017 - 15:22:23 EST


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.

>
> 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.

> +
> +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.

> +
> +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@...

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