ASoC: dsp: mediatek: add mt8195 dsp document

This patch adds mt8195 dsp document. The dsp is used for Sound Open
Firmware driver node. It includes registers,  clocks, memory regions,
and mailbox for dsp.
Signed-off-by: yc.hung <yc.hung@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220106064847.15588-1-yc.hung@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/dsp/mediatek,mt8195-dsp.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dsp/mediatek,mt8195-dsp.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mediatek mt8195 DSP core
+
+maintainers:
+  - YC Hung <yc.hung@mediatek.com>
+
+description: |
+  Some boards from mt8195 contain a DSP core used for
+  advanced pre- and post- audio processing.
+
+properties:
+  compatible:
+    const: mediatek,mt8195-dsp
+
+  reg:
+    items:
+      - description: Address and size of the DSP Cfg registers
+      - description: Address and size of the DSP SRAM
+
+  reg-names:
+    items:
+      - const: cfg
+      - const: sram
+
+  clocks:
+    items:
+      - description: mux for audio dsp clock
+      - description: 26M clock
+      - description: mux for audio dsp local bus
+      - description: default audio dsp local bus clock source
+      - description: clock gate for audio dsp clock
+      - description: mux for audio dsp access external bus
+
+  clock-names:
+    items:
+      - const: adsp_sel
+      - const: clk26m_ck
+      - const: audio_local_bus
+      - const: mainpll_d7_d2
+      - const: scp_adsp_audiodsp
+      - const: audio_h
+
+  power-domains:
+    maxItems: 1
+
+  mboxes:
+    items:
+      - description: ipc reply between host and audio DSP.
+      - description: ipc request between host and audio DSP.
+
+  mbox-names:
+    items:
+      - const: mbox0
+      - const: mbox1
+
+  memory-region:
+    items:
+      - description: dma buffer between host and DSP.
+      - description: DSP system memory.
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - clocks
+  - clock-names
+  - memory-region
+  - power-domains
+  - mbox-names
+  - mboxes
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    dsp@10803000 {
+       compatible =  "mediatek,mt8195-dsp";
+       reg = <0x10803000  0x1000>,
+             <0x10840000  0x40000>;
+       reg-names = "cfg", "sram";
+       clocks = <&topckgen 10>, //CLK_TOP_ADSP
+                <&clk26m>,
+                <&topckgen 107>, //CLK_TOP_AUDIO_LOCAL_BUS
+                <&topckgen 136>, //CLK_TOP_MAINPLL_D7_D2
+                <&scp_adsp 0>, //CLK_SCP_ADSP_AUDIODSP
+                <&topckgen 34>; //CLK_TOP_AUDIO_H
+       clock-names = "adsp_sel",
+                     "clk26m_ck",
+                     "audio_local_bus",
+                     "mainpll_d7_d2",
+                     "scp_adsp_audiodsp",
+                     "audio_h";
+       memory-region = <&adsp_dma_mem_reserved>,
+                       <&adsp_mem_reserved>;
+       power-domains = <&spm 6>; //MT8195_POWER_DOMAIN_ADSP
+       mbox-names = "mbox0", "mbox1";
+       mboxes = <&adsp_mailbox0>, <&adsp_mailbox1>;
+    };