Re: [PATCH] Bluetooth: hci_bcm: Configure SCO routing automatically

Hi Rob,

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Added support to automatically configure the SCO packet routing at the
device setup. The SCO packets are used with the HSP / HFP profiles, but in
some devices (ex. CYW43438) they are routed to a PCM output by default. This
change allows sending the vendor specific HCI command to configure the SCO
routing. The parameters of the command are loaded from the device tree.

Please wrap your commit msg.

Sure.

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Signed-off-by: Attila Tőkés <redacted>
---
.../bindings/net/broadcom-bluetooth.txt       |  7 ++

Please split bindings to separate patch.

Ok, I will split this in two.

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drivers/bluetooth/hci_bcm.c                   | 72 +++++++++++++++++++
2 files changed, 79 insertions(+)

diff --git
a/Documentation/devicetree/bindings/net/broadcom-bluetooth.txt
b/Documentation/devicetree/bindings/net/broadcom-bluetooth.txt
index 4194ff7e..aea3a094 100644

--- a/Documentation/devicetree/bindings/net/broadcom-bluetooth.txt
+++ b/Documentation/devicetree/bindings/net/broadcom-bluetooth.txt

@@ -21,6 +21,12 @@ Optional properties:
 - clocks: clock specifier if external clock provided to the controller
 - clock-names: should be "extclk"

+ SCO routing parameters:
+ - sco-routing: 0-3 (PCM, Transport, Codec, I2S)
+ - pcm-interface-rate: 0-4 (128 Kbps - 2048 Kbps)
+ - pcm-frame-type: 0 (short), 1 (long)
+ - pcm-sync-mode: 0 (slave), 1 (master)
+ - pcm-clock-mode: 0 (slave), 1 (master)

Are these Broadcom specific? Properties need either vendor prefix or
to be documented in a common location. I think these look like the
latter.

These will be used as parameters of a vendor specific (Broadcom/Cypress)
command configuring the SCO packet routing. See the Write_SCO_PCM_Int_Param
command from: http://www.cypress.com/file/298311/download.

The DT should just describe how the h/w is hooked-up. What the s/w has
to do based on that is the driver's problem which is certainly
vendor/chip specific, but that is all irrelevant to the binding.

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What would be the property names with a Broadcom / Cypress vendor prefix?

   brcm,sco-routing
   brcm,pcm-interface-rate
   brcm,pcm-frame-type
   brcm,pcm-sync-mode
   brcm,pcm-clock-mode

?

Yes.

we can do this. However all pcm-* are optional if you switch the HCI transport. And sco-routing should default to HCI if that is not present. Meaning a driver should actively trying to change this. Nevertheless, it would be good if a driver reads the current settings.

In theory we could make sco-routing generic, but so many vendors have different modes, that we better keep this vendor specific.

Regards

Marcel