[PATCH 1/3] Documentation: DT: add Keystone DSP remoteproc binding

On Fri, May 26, 2017 at 11:53:15AM -0500, Suman Anna wrote:

I don't really see what would be unstable here. memory-region is easily 
extended to multiple entries.

+
+The TI Keystone 2 family of SoCs usually have one or more (upto 8) TI DSP Core
+sub-systems that are used to offload some of the processor-intensive tasks or
+algorithms, for achieving various system level goals.
+
+These processor sub-systems 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 in
+Keystone 2 SoCs is usually a TMS320C66x CorePac processor.
+
+DSP Device Node:
+================
+Each DSP Core sub-system is represented as a single DT node. Each node has a
+number of required or optional properties that enable the OS running on the
+host processor (ARM CorePac) to perform the device management of the remote
+processor and to communicate with the remote processor.
+
+Required properties:
+--------------------
+The following are the mandatory properties:
+
+- compatible:		Should be one of the following,
+			    "ti,k2hk-dsp" for DSPs on Keystone 2 66AK2H/K SoCs
+			    "ti,k2l-dsp" for DSPs on Keystone 2 66AK2L SoCs
+			    "ti,k2e-dsp" for DSPs on Keystone 2 66AK2E 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, and
+			should be defined in this order,
+			     "l2sram", "l1pram", "l1dram"
+
+- label:		Should contain a string identifying the DSP instance
+			within the SoC. Should be the string "dsp" followed by
+			the instance number. Eg: "dsp0", "dsp1",..."dsp7" etc

Why does a user need to know or care?

+
+- clocks: 		Should contain the device's input clock, and should be
+			defined as per the bindings in,
+			Documentation/devicetree/bindings/clock/keystone-gate.txt
+
+- ti,syscon-dev:	Should be a pair of the phandle to the Keystone Device
+			State Control node, and the register offset of the DSP
+			boot address register within that node's address space.
+
+- resets:		Should contain the phandle to the reset controller node
+			managing the resets for this device, and a reset
+			specifier. Please refer to the following reset bindings
+			for the reset argument specifier as per SoC,
+			Documentation/devicetree/bindings/reset/ti-syscon-reset.txt
+			    for 66AK2HK/66AK2L/66AK2E SoCs
+
+- interrupt-parent:	Should contain a phandle to the Keystone 2 IRQ controller
+			IP node that is used by the ARM CorePac processor to
+			receive interrupts from the DSP remote processors. See
+			Documentation/devicetree/bindings/interrupt-controller/ti,keystone-irq.txt
+			for details.
+
+- interrupts: 		Should contain an entry for each value in 'interrupt-names'.
+			Each entry should have the interrupt source number used by
+			the remote processor to the host processor. The values should
+			follow the interrupt-specifier format as dictated by the
+			'interrupt-parent' node. The purpose of each is as per the
+			description in the 'interrupt-names' property.
+
+- interrupt-names:	Should contain strings with the following names, each
+			representing a specific interrupt,
+			    "vring" - interrupt for virtio based IPC
+			    "exception" - interrupt for exception notification
+
+- kick-gpio: 		Should specify the gpio device needed for the virtio IPC

-gpios

+			stack. This will be used to interrupt the remote processor.
+			The gpio device to be used is as per the bindings in,
+			Documentation/devicetree/bindings/gpio/gpio-dsp-keystone.txt
+
+Optional properties:
+--------------------
+
+- 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
+
+
+Example:
+--------
+
+	/* 66AK2H/K DSP node in SoC DTS file */
+	soc {
+		dsp0: dsp at 10800000 {
+			compatible = "ti,k2hk-dsp";
+			reg = <0x10800000 0x00100000>,
+			      <0x10e00000 0x00008000>,
+			      <0x10f00000 0x00008000>;
+			reg-names = "l2sram", "l1pram", "l1dram";
+			label = "dsp0";
+			clocks = <&clkgem0>;
+			ti,syscon-dev = <&devctrl 0x40>;
+			resets = <&pscrst 0>;
+			interrupt-parent = <&kirq0>;
+			interrupts = <0 8>;
+			interrupt-names = "vring", "exception";
+			kick-gpio = <&dspgpio0 27 0>;
+		};
+
+	};
+
+	/* K2HK EVM Board file */
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		dsp_common_cma_pool: dsp_common_cma_pool at 81f800000 {
+			compatible = "shared-dma-pool";
+			reg = <0x00000008 0x1f800000 0x00000000 0x800000>;
+			reusable;
+			status = "okay";
+		};
+	};
+
+	&dsp0 {
+		memory-region = <&dsp_common_cma_pool>;
+	};
-- 
2.12.0