On 22/02/18 00:14, Rob Herring wrote:
On Tue, Feb 20, 2018 at 3:33 AM, Srinivas Kandagatla
<srinivas.kandaga...@linaro.org> wrote:
Thanks for your review comments,

On 18/02/18 23:04, Rob Herring wrote:

On Wed, Feb 14, 2018 at 09:13:23AM +0000, Srinivas Kandagatla wrote:

Thanks for the review,

On 13/02/18 23:12, Rob Herring wrote:

On Tue, Feb 13, 2018 at 04:58:13PM +0000, srinivas.kandaga...@linaro.org

From: Srinivas Kandagatla <srinivas.kandaga...@linaro.org>

This patch add dt bindings for Qualcomm APR (Asynchronous Packet
bus driver. This bus is used for communicating with DSP which provides
audio and various other services to cpu.

Signed-off-by: Srinivas Kandagatla <srinivas.kandaga...@linaro.org>
    .../devicetree/bindings/soc/qcom/qcom,apr.txt      | 83
    1 file changed, 83 insertions(+)
    create mode 100644

diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,apr.txt
new file mode 100644
index 000000000000..1b95fbfed348
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/qcom/qcom,apr.txt
@@ -0,0 +1,83 @@
+Qualcomm APR (Asynchronous Packet Router) binding
+This binding describes the Qualcomm APR. APR is a IPC protocol for
+communication between Application processor and QDSP. APR is mainly
+used for audio/voice services on the QDSP.

It's not a good design generally to mix different types of nodes at one

I agree, may be I can split the services and devices into different
like below, which should avoid mixing different types of nodes.

Does this sound good to you?

Seems your original example wasn't so complete...

Yep, I will fix it in next version.

I don't see why you need all these nodes in the first place. For a
single SoC, how much does all this vary?

It might not vary for a given SoC, but It does vary across the SoCs.
Also the versions of each service are independent to each other.

Not sure I follow the last statement. Meaning firmware updates change
the services?
Sorry for not being clear, so the services like AFE, ASM, ADM have different version numbers for a given SoC/firmware.

Not 100% sure if firmware updates would change the service version number, even if it does, it can be queried dynamically on new B family SoCs, and on older A Family SoCs I have not seen the firmware updates in last 4 years.

I don't see any versioning of services here.

Yes, Plan is that it will be part of the compatible string in cases where version query is not supported on older QCOM A family SoCs.
On B Family SoCs we can query the version dynamically.

apr {
          compatible = "qcom,apr-v2";
          qcom,smd-channels = "apr_audio_svc";
          qcom,apr-dest-domain-id = <APR_DOMAIN_ADSP>;

          apr-services {
                  q6core {
                          qcom,apr-svc-name = "CORE";
                          qcom,apr-svc-id = <APR_SVC_ADSP_CORE>;
                          compatible = "qcom,q6core";

                  q6afe: q6afe {
                          compatible = "qcom,q6afe";
                          qcom,apr-svc-name = "AFE";
                          qcom,apr-svc-id = <APR_SVC_AFE>;
                          #sound-dai-cells = <1>;

                  q6asm: q6asm {
                          compatible = "qcom,q6asm";
                          qcom,apr-svc-name = "ASM";
                          qcom,apr-svc-id = <APR_SVC_ASM>;
                          #sound-dai-cells = <1>;

                  q6adm: q6adm {
                          compatible = "qcom,q6adm";
                          qcom,apr-svc-name = "ADM";
                          qcom,apr-svc-id = <APR_SVC_ADM>;
                          #sound-dai-cells = <0>;

All these DAI nodes could be a single node and the cell value be the

So we will have 2 cell values, one representing the apr service and other the dai.

No, DAI's here are both backends and frontends, and some of the services
like core, USM are not DAI's

Are you also saying that we should have a single driver entity for all these

DT nodes do not equate driver entities. A driver can instantiate other drivers.

Am I saying a single DT node for this? Yes, perhaps.
Yes, I will give that a go.

So we will endup having something like this in DT for one frontend and backend dailink:

apr {
        compatible = "qcom,apr-v2";
        qcom,smd-channels = "apr_audio_svc";
        qcom,apr-dest-domain-id = <APR_DOMAIN_ADSP>

        q6audio: audiosvc {
                compatible = "qcom,q6audio-svc";
                qcom,apr-svcs = <APR_SVC_CORE APR_SVC_AFE APR_SVC_ASM>;
                qcom,apr-svc-names = "CORE", "AFE", "ASM";

        sndcard {
                compatible = "qcom,msm8996-snd-card"
                qcom,model = "DB820c";
                qcom,audio-routing =
                        "RX_BIAS", "MCLK";
                fe@1 {
                        link-name = "MultiMedia1";
                        cpu {
                                sound-dai = <&q6audio  APR_SVC_ASM MM1>       
                        platform {
                                sound-dai = <&q6audio APR_SVC_ASM MM1>;

                be@1 {
                        link-name = "HDMI Playback";
                        cpu {
                                sound-dai = <&q6audio APR_SVC_AFE HDMI>;

                        platform {
                                sound-dai = <&q6audio ARP_SVC_ADM>;

                        codec {
                                sound-dai = <&hdmi 0>;


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