[PATCH v2 6/8] platform/chrome: cros_ec_typec: Use Thunderbolt 3 cable discover mode VDO in USB4 mode

Utkarsh Patel
2020-11-13T20:27:17Z

Configure Thunderbolt3/USB4 cable generation value by filing Thunderbolt 3
cable discover mode VDO to support rounded and non-rounded Thunderbolt3/
USB4 cables.
While we are here use Thunderbolt 3 cable discover mode VDO to fill active
cable plug link training value.

Suggested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Utkarsh Patel <utkarsh.h.patel@intel.com>

--
Changes in v2:
- No change.
--
---
drivers/platform/chrome/cros_ec_typec.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 8111ed1fc574..b7416e82c3b3 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -514,8 +514,18 @@ static int cros_typec_enable_usb4(struct cros_typec_data *typec,
else if (pd_ctrl->control_flags & USB_PD_CTRL_ACTIVE_CABLE)
data.eudo |= EUDO_CABLE_TYPE_RE_TIMER << EUDO_CABLE_TYPE_SHIFT;

- data.active_link_training = !!(pd_ctrl->control_flags &
- USB_PD_CTRL_ACTIVE_LINK_UNIDIR);
+ /*
+ * This driver does not have access to the identity information or
+ * capabilities of the cable, so we don't know is it a real USB4 or
+ * TBT3 cable. Therefore pretending that it's always TBT3 cable by
+ * filling the TBT3 Cable VDO.
+ */
+ data.tbt_cable_vdo = TBT_MODE;
+
+ if (pd_ctrl->control_flags & USB_PD_CTRL_ACTIVE_LINK_UNIDIR)
+ data.tbt_cable_vdo |= TBT_CABLE_LINK_TRAINING;
+
+ data.tbt_cable_vdo |= TBT_SET_CABLE_ROUNDED(pd_ctrl->cable_gen);

port->state.alt = NULL;
port->state.data = &data;
--
2.17.1