On 23/05/2022 11:21, Hakan Jansson wrote: > Hi Krzysztof, > > Thanks for responding. > > On 5/22/2022 10:14 AM, Krzysztof Kozlowski wrote: >>> Some devices (e.g. CYW5557x) require autobaud mode to enable FW loading. >> Which devices support this? You probably need allOf:if:then. > > Most devices _support_ autobaud mode but I don't have a definitive list. > The CYW5557x is the first device family to _require_ autobaud mode for > FW loading as far as I know. > >>> Autobaud mode can also be required on some boards where the controller >>> device is using a non-standard baud rate when first powered on. >>> >>> This patch adds a property, "brcm,uses-autobaud-mode", to enable autobaud >>> mode selection. >> Don't use "This patch": >> https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95 > > Sorry, will change in next rev. > >>> Signed-off-by: Hakan Jansson <hakan.jansson@xxxxxxxxxxxx> >>> --- >>> V1 -> V2: Modify property description >>> >>> .../devicetree/bindings/net/broadcom-bluetooth.yaml | 9 +++++++++ >>> 1 file changed, 9 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/net/broadcom-bluetooth.yaml b/Documentation/devicetree/bindings/net/broadcom-bluetooth.yaml >>> index 5aac094fd217..a29f059c21cc 100644 >>> --- a/Documentation/devicetree/bindings/net/broadcom-bluetooth.yaml >>> +++ b/Documentation/devicetree/bindings/net/broadcom-bluetooth.yaml >>> @@ -92,6 +92,15 @@ properties: >>> pcm-sync-mode: slave, master >>> pcm-clock-mode: slave, master >>> >>> + brcm,uses-autobaud-mode: >> Based on description, I understand the host triggers using autobaud. > > Correct, the host triggers using autobaud. > >> However here you word it as "uses", so it is independent of host, it >> looks like property of a device. > > I've been thinking of it as a a property of a specific board HW, > inherited either from a property of the device being used or from a > property of the HW design (e.g. a PCB using an alternate crystal > frequency yielding a non-standard baud rate). > >> The commit msg describes it even >> different - "require autobaud". > > Yes, the commit message describes two separate reasons why autobaud mode > would be required: > > 1. Requirement coming from Device: "Some devices (e.g. CYW5557x) require > autobaud mode to enable FW loading." > > 2. Requirement coming from HW design: "Autobaud mode can also be > required on some boards where the controller device is using a > non-standard baud rate when first powered on." > >> This leads to second issue - it looks like there is some hardware >> property (requiring to use autobaud) which should be described by >> bindings. But instead you describe desired operational feature. > > Sorry about that. I've really been struggling with what should go into > the description. Any suggestions or hints would be much appreciated. > > How about, changing the property name to "brcm,requires-autobaud-mode" > and the description to: > "Set this property if autobaud mode is required. Autobaud mode is > required if the device's baud rate in normal mode is not supported by > the host or if the device requires autobaud mode startup before loading FW." > > Would that be an appropriate name and description? Yes, sounds good. I also have trouble to name it nicely. Sorry for late reply. Best regards, Krzysztof
