Re: [PATCH v3] usb: typec: get the vbus source and charge values from the devicetree

[Angus Ainslie]

On 2018-09-11 09:33, Guenter Roeck wrote:
> I cant put my finger on it but this seems wrong. As i said both src
> and sink should never be true at the same time. I also dinât
> understand why turning off src should power off your board. Ultimately
> my concern is that we may be just painting over the real problem, and
> that would be really bad to do with dt properties.

I agree that this doesn't seem like the correct way of solving the 
problem. On this HW (Emcraft iMX8M BSB) I think the PTN5110 chip has 
been connected correctly so I'm assuming that it is some quirk of the 
PTN5110.

I didn't design the HW or the chip. This is a workaround for "quirky" 
hardware and there may be others that don't behave exactly as expected.

> Note that sending to groeck7@ makes it hard for me to see your emails
> and to reply. Using linux@xxxxxxxxxxxx would be much better.

Ok, I think that email was grabbed from the driver source.

> Guenter
>
> Sent from my iPhone
>
> > On Sep 11, 2018, at 7:59 AM, Angus Ainslie (Purism) <angus@xxxxxxxx> 
> > wrote:
> >
> > If the board is being powered by USB disabling the source and sink
> > can remove power from the board. Allow the source and sink to be
> > initallized based on devicetree values.
> >
> > Changed since V2:
> >
> > Change the devicetree documentation.
> > Change the devicetree property names.
> >
> > Changed since V1:
> >
> > use devicetree values instead of hardcoded initialization.
> >
> > Signed-off-by: Angus Ainslie (Purism) <angus@xxxxxxxx>
> > ---
> > .../devicetree/bindings/usb/typec-tcpci.txt        |  6 ++++++
> > drivers/usb/typec/tcpm.c                           | 14 +++++++++++---
> > 2 files changed, 17 insertions(+), 3 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/usb/typec-tcpci.txt 
> > b/Documentation/devicetree/bindings/usb/typec-tcpci.txt
> > index 0dd1469e7318..b07418ae6482 100644
> > --- a/Documentation/devicetree/bindings/usb/typec-tcpci.txt
> > +++ b/Documentation/devicetree/bindings/usb/typec-tcpci.txt
> > @@ -15,6 +15,12 @@ Required sub-node:
> >   of connector node are specified in
> >   Documentation/devicetree/bindings/connector/usb-connector.txt
> >
> > +Optional properties for usb-c-connector sub-node:
> > +- init-vbus-source: set the initalization value for vbus-source to 
> > true.
> > +  If this property is not present the initial value will be false.
> > +- init-vbus-sink: set the initalization value for vbus-sink to true.
> > +  If this property is not present the initial value will be false.
> > +
> > Example:
> >
> > ptn5110@50 {
> > diff --git a/drivers/usb/typec/tcpm.c b/drivers/usb/typec/tcpm.c
> > index ca7bedb46f7f..10c14ece3858 100644
> > --- a/drivers/usb/typec/tcpm.c
> > +++ b/drivers/usb/typec/tcpm.c
> > @@ -2462,9 +2462,7 @@ static int tcpm_init_vbus(struct tcpm_port 
> > *port)
> > {
> >    int ret;
> >
> > -    ret = port->tcpc->set_vbus(port->tcpc, false, false);
> > -    port->vbus_source = false;
> > -    port->vbus_charge = false;
> > +    ret = port->tcpc->set_vbus(port->tcpc, port->vbus_source, 
> > port->vbus_charge);
> >    return ret;
> > }
> >
> > @@ -4266,6 +4264,16 @@ static int tcpm_fw_get_caps(struct tcpm_port 
> > *port,
> >        return -EINVAL;
> >    port->port_type = port->typec_caps.type;
> >
> > +    if (fwnode_property_present(fwnode, "init-vbus-source"))
> > +        port->vbus_source = true;
> > +    else
> > +        port->vbus_source = false;
> > +
> > +    if (fwnode_property_present(fwnode, "init-vbus-sink"))
> > +            port->vbus_charge = true;
> > +    else
> > +            port->vbus_charge = false;
> > +
> >    if (port->port_type == TYPEC_PORT_SNK)
> >        goto sink;
> >
> > --
> > 2.17.1