| Message ID | 20240315112745.63230-13-bastien.curutchet@bootlin.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | ASoC: ti: davinci-i2s: Add features to McBSP driver | expand |
On Fri, 15 Mar 2024 12:27:44 +0100, Bastien Curutchet wrote: > McBSP is able to handle capture and playback stream. > The McBSP's DX pins that outputs serial data during playback streams can > be used to output a chosen pattern during capture streams. For instance, > this can be useful to drive an active-low signal during capture streams > (by choosing <0> as pattern) > > Add a 'ti,drive-dx' property that can be used to repeatedly output a > chosen pattern on DX pin while capture stream is ON. > > Signed-off-by: Bastien Curutchet <bastien.curutchet@bootlin.com> > --- > Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml | 7 +++++++ > 1 file changed, 7 insertions(+) > Reviewed-by: Rob Herring <robh@kernel.org>
On 15/03/2024 13:27, Bastien Curutchet wrote: > McBSP is able to handle capture and playback stream. > The McBSP's DX pins that outputs serial data during playback streams can > be used to output a chosen pattern during capture streams. For instance, > this can be useful to drive an active-low signal during capture streams > (by choosing <0> as pattern) or configure the MCBSPx.DX pin as GPO and use it as a GPIO? Quite novel use of the hardware, no doubt about it. If you don't have DMA servicing the TX, it will just re-transmit the word from from the DXR register when the transmitter is pulled out of reset. Interesting, but I'm not sure if this belongs to DT. > Add a 'ti,drive-dx' property that can be used to repeatedly output a > chosen pattern on DX pin while capture stream is ON. > > Signed-off-by: Bastien Curutchet <bastien.curutchet@bootlin.com> > --- > Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml b/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml > index d8d4e7ea6e02..f4d1fc6bcd61 100644 > --- a/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml > +++ b/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml > @@ -80,6 +80,13 @@ properties: > Enable synchronisation error detections when an unexpected frame pulse is > received. If not present, unexpected frame pulses are ignored. > > + ti,drive-dx: > + $ref: /schemas/types.yaml#/definitions/uint32 > + description: > + If the property is present, McBSP will repeatedly output the selected > + value on DX pin during capture streams. For instance, if set to 0, this > + can be used to drive an active-low signal. > + > required: > - "#sound-dai-cells" > - compatible
Hi Péter, On 3/19/24 19:02, Péter Ujfalusi wrote: > > > On 15/03/2024 13:27, Bastien Curutchet wrote: >> McBSP is able to handle capture and playback stream. >> The McBSP's DX pins that outputs serial data during playback streams can >> be used to output a chosen pattern during capture streams. For instance, >> this can be useful to drive an active-low signal during capture streams >> (by choosing <0> as pattern) > > or configure the MCBSPx.DX pin as GPO and use it as a GPIO? In my use case, DX pin is connected to the ADC chip select pin so I want the DX pin to toggle the closest possible to capture's start. That's why I introduced this feature over configuring the pin as GPO. > > Quite novel use of the hardware, no doubt about it. If you don't have > DMA servicing the TX, it will just re-transmit the word from from the > DXR register when the transmitter is pulled out of reset. > > Interesting, but I'm not sure if this belongs to DT. > >> Add a 'ti,drive-dx' property that can be used to repeatedly output a >> chosen pattern on DX pin while capture stream is ON. >> >> Signed-off-by: Bastien Curutchet <bastien.curutchet@bootlin.com> >> --- >> Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml b/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml >> index d8d4e7ea6e02..f4d1fc6bcd61 100644 >> --- a/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml >> +++ b/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml >> @@ -80,6 +80,13 @@ properties: >> Enable synchronisation error detections when an unexpected frame pulse is >> received. If not present, unexpected frame pulses are ignored. >> >> + ti,drive-dx: >> + $ref: /schemas/types.yaml#/definitions/uint32 >> + description: >> + If the property is present, McBSP will repeatedly output the selected >> + value on DX pin during capture streams. For instance, if set to 0, this >> + can be used to drive an active-low signal. >> + >> required: >> - "#sound-dai-cells" >> - compatible > Best regards, Bastien
diff --git a/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml b/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml index d8d4e7ea6e02..f4d1fc6bcd61 100644 --- a/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml +++ b/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml @@ -80,6 +80,13 @@ properties: Enable synchronisation error detections when an unexpected frame pulse is received. If not present, unexpected frame pulses are ignored. + ti,drive-dx: + $ref: /schemas/types.yaml#/definitions/uint32 + description: + If the property is present, McBSP will repeatedly output the selected + value on DX pin during capture streams. For instance, if set to 0, this + can be used to drive an active-low signal. + required: - "#sound-dai-cells" - compatible
McBSP is able to handle capture and playback stream. The McBSP's DX pins that outputs serial data during playback streams can be used to output a chosen pattern during capture streams. For instance, this can be useful to drive an active-low signal during capture streams (by choosing <0> as pattern) Add a 'ti,drive-dx' property that can be used to repeatedly output a chosen pattern on DX pin while capture stream is ON. Signed-off-by: Bastien Curutchet <bastien.curutchet@bootlin.com> --- Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml | 7 +++++++ 1 file changed, 7 insertions(+)