TI Keystone DSP devices
=======================
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, and should also
have an alias with the stem 'rproc' defined. 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
"ti,k2g-dsp" for DSPs on Keystone 2 66AK2G 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"
- 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 either of 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 or,
Documentation/devicetree/bindings/reset/ti,sci-reset.yaml
for 66AK2G SoCs
- 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-gpios: Should specify the gpio device needed for the virtio IPC
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
SoC-specific Required properties:
---------------------------------
The following are mandatory properties for Keystone 2 66AK2HK, 66AK2L and 66AK2E
SoCs only:
- clocks: Should contain the device's input clock, and should be
defined as per the bindings in,
Documentation/devicetree/bindings/clock/keystone-gate.txt
The following are mandatory properties for Keystone 2 66AK2G SoCs only:
- power-domains: Should contain a phandle to a PM domain provider node
and an args specifier containing the DSP device id
value. This property is as per the binding,
Documentation/devicetree/bindings/soc/ti/sci-pm-domain.yaml
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
Examples:
---------
1.
/* 66AK2H/K DSP aliases */
aliases {
rproc0 = &dsp0;
rproc1 = &dsp1;
rproc2 = &dsp2;
rproc3 = &dsp3;
rproc4 = &dsp4;
rproc5 = &dsp5;
rproc6 = &dsp6;
rproc7 = &dsp7;
};
/* 66AK2H/K DSP memory node */
reserved-memory {
#address-cells = <2>;
#size-cells = <2>;
ranges;
dsp_common_memory: dsp-common-memory@81f800000 {
compatible = "shared-dma-pool";
reg = <0x00000008 0x1f800000 0x00000000 0x800000>;
reusable;
};
};
/* 66AK2H/K DSP node */
soc {
dsp0: dsp@10800000 {
compatible = "ti,k2hk-dsp";
reg = <0x10800000 0x00100000>,
<0x10e00000 0x00008000>,
<0x10f00000 0x00008000>;
reg-names = "l2sram", "l1pram", "l1dram";
clocks = <&clkgem0>;
ti,syscon-dev = <&devctrl 0x40>;
resets = <&pscrst 0>;
interrupt-parent = <&kirq0>;
interrupts = <0 8>;
interrupt-names = "vring", "exception";
kick-gpios = <&dspgpio0 27 0>;
memory-region = <&dsp_common_memory>;
};
};
2.
/* 66AK2G DSP alias */
aliases {
rproc0 = &dsp0;
};
/* 66AK2G DSP memory node */
reserved-memory {
#address-cells = <2>;
#size-cells = <2>;
ranges;
dsp_common_memory: dsp-common-memory@81f800000 {
compatible = "shared-dma-pool";
reg = <0x00000008 0x1f800000 0x00000000 0x800000>;
reusable;
};
};
/* 66AK2G DSP node */
soc {
dsp0: dsp@10800000 {
compatible = "ti,k2g-dsp";
reg = <0x10800000 0x00100000>,
<0x10e00000 0x00008000>,
<0x10f00000 0x00008000>;
reg-names = "l2sram", "l1pram", "l1dram";
power-domains = <&k2g_pds 0x0046>;
ti,syscon-dev = <&devctrl 0x40>;
resets = <&k2g_reset 0x0046 0x1>;
interrupt-parent = <&kirq0>;
interrupts = <0 8>;
interrupt-names = "vring", "exception";
kick-gpios = <&dspgpio0 27 0>;
memory-region = <&dsp_common_memory>;
};
};