Thread (9 messages) flat view 9 messages, 4 authors, 2021-09-09

Re: [PATCH v2 2/2] dt-bindings: dsp: fsl: Add DSP optional clocks documentation

From: Rob Herring <robh@kernel.org>
Date: 2021-09-03 16:53:48
Also in: alsa-devel, lkml

On Fri, Sep 03, 2021 at 05:53:40PM +0300, Daniel Baluta wrote:
quoted hunk ↗ jump to hunk
From: Daniel Baluta <daniel.baluta@nxp.com>

DSP node on the Linux kernel side must also take care of enabling
DAI/DMA related clocks.

By design we choose to manage DAI/DMA clocks from the kernel side because of
the architecture of some i.MX8 boards.

Clocks are handled by a special M4 core which runs a special firmware
called SCFW (System Controler firmware).

This communicates with A cores running Linux via a special Messaging
Unit and implements a custom API which is already implemented by the
Linux kernel i.MX clocks implementation.

Note that these clocks are optional. We can use the DSP without them.

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
 .../devicetree/bindings/dsp/fsl,dsp.yaml      | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)
diff --git a/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml b/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml
index 7afc9f2be13a..1453668c0194 100644
--- a/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml
+++ b/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml
@@ -24,16 +24,49 @@ properties:
     maxItems: 1
 
   clocks:
+    minItems: 3
     items:
       - description: ipg clock
       - description: ocram clock
       - description: core clock
+      - description: esai0 core clock for accessing registers
+      - description: esai0 baud clock
+      - description: esai0 system clock
+      - description: esai0 spba clock required when ESAI is placed in slave mode
+      - description: SAI1 bus clock
+      - description: SAI1 master clock 0
+      - description: SAI1 master clock 1
+      - description: SAI1 master clock 2
+      - description: SAI1 master clock 3
+      - description: SAI3 bus clock
+      - description: SAI3 master clock 0
+      - description: SAI3 master clock 1
+      - description: SAI3 master clock 2
+      - description: SAI3 master clock 3
+      - description: SDMA3 root clock used for accessing registers
Sigh, I just rejected this kind of thing for the other i.MX8 DSP 
binding[1].

Add a reference to the h/w block and then get the clocks (and other 
resources) from there.

Rob

[1] https://lore.kernel.org/linux-devicetree/YTDq%2FkWFPLHUnHMN@robh.at.kernel.org/ (local)
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