Messages in this thread | | | Date | Mon, 8 Apr 2024 14:01:10 +0200 | Subject | Re: [PATCHv3 1/2] dt-bindings: usb: typec: anx7688: start a binding document | From | Krzysztof Kozlowski <> |
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On 08/04/2024 13:51, Ondřej Jirman wrote: > Hi Krzysztof, > > On Mon, Apr 08, 2024 at 01:17:32PM GMT, Krzysztof Kozlowski wrote: >> On 08/04/2024 12:51, Pavel Machek wrote: >>> Add binding for anx7688 usb type-c bridge. I don't have a datasheet, >>> but I did best I could. >>> >>> Signed-off-by: Pavel Machek <pavel@ucw.cz> >> >> ... >> >>> + cabledet-gpios: >>> + maxItems: 1 >>> + description: GPIO controlling CABLE_DET (C3) pin. >>> + >>> + avdd10-supply: >>> + description: 1.0V power supply going to AVDD10 (A4, ...) pins >>> + >>> + dvdd10-supply: >>> + description: 1.0V power supply going to DVDD10 (D6, ...) pins >>> + >>> + avdd18-supply: >>> + description: 1.8V power supply going to AVDD18 (E3, ...) pins >>> + >>> + dvdd18-supply: >>> + description: 1.8V power supply going to DVDD18 (G4, ...) pins >>> + >>> + avdd33-supply: >>> + description: 3.3V power supply going to AVDD33 (C4, ...) pins >>> + >>> + i2c-supply: true >>> + vconn-supply: true >> >> There are no such supplies like i2c and vconn on the schematics. > > Which schematics? > > ANX7688 has VCONN1/2_EN GPIOs that control a switching of VCONN power supply > to resective CCx pins. That's just a switch signal. Power for VCONN needs > to come from somewhere and the driver needs to enable the regulator at > the appropriate time only. > > On Pinephone it can't be an always on power supply and needs to be enabled > only when used due to HW design of the circuit. (default without ANX driver > initialized would be to shove 5V to both CC pins, which breaks Type-C spec) > > I2C supply is needed for I2C bus to work, apparently. There's nothing > that says that I2C pull-ups supply has to come from supplies powering the > chip. I2C I/O is open drain and the device needs to enable a bus supply > in order to communicate.
No, that's misunderstanding of DT. These are not supplies to anx7688.
Bus supply is not related to anx7688.
> > You can say that bus master should be managing the bus supply, but you'd still > have a problem that each device may be behind a voltage translator, and > logically, bus master driver should care only about its side of the bus then. > Both side of level shifter need the pull-up power enabled.
Again, that's nothing related to anx7688. If you want to add it here, why not to every device everywhere?
> > You can also make an argument that bus supply can be always on, but that > causes several other issues on Pinephone due to shared nature of most > resources like these. There are other devices on shared power rails, that > need to be turned off during sleep, etc. >
No, do not add non-existing properties on this device as workaround for other issues.
Please drop these two supplies *and all other which do not exist* on anx7688.
Best regards, Krzysztof
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