[PATCH v6 03/14] usb: typec: tcpci: update ROLE_CONTROL for DRP

Badhri Jagan Sridharan
2020-09-01T02:59:56Z

ROLE_CONTROL register would not have the actual CC terminations
unless the port does not set ROLE_CONTROL.DRP. For DRP ports,
CC_STATUS.cc1/cc2 indicates the final terminations applied
when TCPC enters potential_connect_as_source/_sink.
For DRP ports, infer port role from CC_STATUS and set corresponding
CC terminations before setting the orientation.

Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
---
Changes since v1:
- Changing patch version to v6 to fix version number confusion.
---
drivers/usb/typec/tcpm/tcpci.c | 37 +++++++++++++++++++++++++++++++++-
1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index 7d36d5e2d3f7..7d9491ba62fb 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -191,12 +191,47 @@ static int tcpci_set_polarity(struct tcpc_dev *tcpc,
struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
unsigned int reg;
int ret;
+ enum typec_cc_status cc1, cc2;

- /* Keep the disconnect cc line open */
+ /* Obtain Rp setting from role control */
ret = regmap_read(tcpci->regmap, TCPC_ROLE_CTRL, &reg);
if (ret < 0)
return ret;

+ ret = tcpci_get_cc(tcpc, &cc1, &cc2);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * When port has drp toggling enabled, ROLE_CONTROL would only have the initial
+ * terminations for the toggling and does not indicate the final cc
+ * terminations when ConnectionResult is 0 i.e. drp toggling stops and
+ * the connection is resolbed. Infer port role from TCPC_CC_STATUS based on the
+ * terminations seen. The port role is then used to set the cc terminations.
+ */
+ if (reg & TCPC_ROLE_CTRL_DRP) {
+ /* Disable DRP for the OPEN setting to take effect */
+ reg = reg & ~TCPC_ROLE_CTRL_DRP;
+
+ if (polarity == TYPEC_POLARITY_CC2) {
+ reg &= ~(TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT);
+ /* Local port is source */
+ if (cc2 == TYPEC_CC_RD)
+ /* Role control would have the Rp setting when DRP was enabled */
+ reg |= TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT;
+ else
+ reg |= TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC2_SHIFT;
+ } else {
+ reg &= ~(TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT);
+ /* Local port is source */
+ if (cc1 == TYPEC_CC_RD)
+ /* Role control would have the Rp setting when DRP was enabled */
+ reg |= TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT;
+ else
+ reg |= TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC1_SHIFT;
+ }
+ }
+
if (polarity == TYPEC_POLARITY_CC2)
reg |= TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC1_SHIFT;
else
--
2.28.0.402.g5ffc5be6b7-goog