I would say;
"VDDD is an optional supply and could be unconnected on designs. In this case an internal regulator is used."
The original sentence has 'and' twice, which looks a little weird in English. I will also advocate "could" instead of "can," since it's the past tense (i.e. the board is already designed and we are merely describing a board in the binding, not dictating design methodology in the binding). That said,
Signed-off-by: Matt Sealey matt@genesi-usa.com
I have a question that is slightly related.
It is possible to direct the SGTL5000 VDDD charge pump source to VDDA or VDDIO via CHIP_LINREG_CTRL. It is automatically set to the highest voltage of VDDA/VDDIO (differing voltages) or VDDA (both the same and higher than 3.1V) at "start."
It may be prudent for some boards that supply >3.1V to dictate switching to VDDIO as the charge pump supply, and I wonder how we'd actually define that. Supplying a regulator for VDDD and matching it would not suit the case where a single 3.3V supply went to all supplies (VDDD, VDDA, VDDIO) which I have seen. It would need a property.. VDDD-source maybe?
If you were going for a low-noise design without a dedicated VDDD, I would think you'd want to keep VDDA decoupled from the digital logic and that isn't the default..
On Mon, May 13, 2013 at 10:39 AM, Fabio Estevam fabio.estevam@freescale.com wrote:
sgtl5000 has two power supplies that are mandatory: VDDA and VDDIO.
VDDD is an optional supply and can be left unconnected and in this case an internal regulator is used.
Signed-off-by: Fabio Estevam fabio.estevam@freescale.com
.../devicetree/bindings/sound/sgtl5000.txt | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/sgtl5000.txt b/Documentation/devicetree/bindings/sound/sgtl5000.txt index 9cc4444..3537a7d 100644 --- a/Documentation/devicetree/bindings/sound/sgtl5000.txt +++ b/Documentation/devicetree/bindings/sound/sgtl5000.txt @@ -5,9 +5,19 @@ Required properties:
- reg : the I2C address of the device
+- VDDA-supply: the regulator for VDDA supply
+- VDDIO-supply: the regulator for VDDIO supply
+Optional properties:
+- VDDD-supply: the regulator for VDDD supply
Example:
codec: sgtl5000@0a { compatible = "fsl,sgtl5000"; reg = <0x0a>;
VDDA-supply = <&vdda_reg>;VDDIO-supply = <&vddio_reg>;};
1.7.9.5