On 2018-09-07 06:55, Guenter Roeck wrote:
On 09/07/2018 03:34 AM, Heikki Krogerus wrote:
On Thu, Sep 06, 2018 at 01:26:44PM -0600, Angus Ainslie (Purism) wrote:
If the board is being powered by USB disabling the source and sink
can remove power from the board. Default to source and sink enabled.
Seems to me that might violate the specification, and cause trouble for systems
where vbus has to be off initially. It may be better to provide this kind of
information as configuration parameter instead of imposing it on everyone.
It felt like it would not be the correct thing to do either. I've tried re-arranging the code in tcpci.c to enable the sink before disabling the source but the only way I found to not disable the power was by setting both of those to true.
What about adding some device tree entries for the initial vbus state and default to false if they are not present ?
init-vbus-source and init-vbus-charge ?
Signed-off-by: Angus Ainslie (Purism) <angus@xxxxxxxx>
Â drivers/usb/typec/tcpm.c | 8 +++++---
Â 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/typec/tcpm.c b/drivers/usb/typec/tcpm.c
index ca7bedb46f7f..a1b819cf31da 100644
@@ -2462,9 +2462,11 @@ static int tcpm_init_vbus(struct tcpm_port *port)
ÂÂÂÂÂ int ret;
Â -ÂÂÂ ret = port->tcpc->set_vbus(port->tcpc, false, false);
-ÂÂÂ port->vbus_source = false;
-ÂÂÂ port->vbus_charge = false;
+ÂÂÂ /* default to source and sink enabled in case USB is our only power
+ÂÂÂÂ * source */
I am personally in favor of standard multi-line comments.
+ÂÂÂ ret = port->tcpc->set_vbus(port->tcpc, true, true);
+ÂÂÂ port->vbus_source = true;
+ÂÂÂ port->vbus_charge = true;
ÂÂÂÂÂ return ret;