platform/chrome: cros_ec_typec: Add Displayport Alternatemode 2.1 Support

Displayport Alternatemode 2.1 requires cable capabilities such as cable
signalling, cable type, DPAM version which then will be used by mux
driver for displayport configuration. These capabilities can be derived
from the Cable VDO.

Acked-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Utkarsh Patel <utkarsh.h.patel@intel.com>
Link: https://lore.kernel.org/r/20230920023243.2494410-5-utkarsh.h.patel@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index d0b4d3fc40ed8fa9e85ac6b9698784bbbc4e3264..cca913400b39b1a5a16438b498a8a614767efe53 100644 (file)
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -492,6 +492,8 @@ static int cros_typec_enable_dp(struct cros_typec_data *typec,
 {
        struct cros_typec_port *port = typec->ports[port_num];
        struct typec_displayport_data dp_data;
+       u32 cable_tbt_vdo;
+       u32 cable_dp_vdo;
        int ret;
 
        if (typec->pd_ctrl_ver < 2) {
@@ -524,6 +526,32 @@ static int cros_typec_enable_dp(struct cros_typec_data *typec,
        port->state.data = &dp_data;
        port->state.mode = TYPEC_MODAL_STATE(ffs(pd_ctrl->dp_mode));
 
+       /* Get cable VDO for cables with DPSID to check DPAM2.1 is supported */
+       cable_dp_vdo = cros_typec_get_cable_vdo(port, USB_TYPEC_DP_SID);
+
+       /**
+        * Get cable VDO for thunderbolt cables and cables with DPSID but does not
+        * support DPAM2.1.
+        */
+       cable_tbt_vdo = cros_typec_get_cable_vdo(port, USB_TYPEC_TBT_SID);
+
+       if (cable_dp_vdo & DP_CAP_DPAM_VERSION) {
+               dp_data.conf |= cable_dp_vdo;
+       } else if (cable_tbt_vdo) {
+               dp_data.conf |=  TBT_CABLE_SPEED(cable_tbt_vdo) << DP_CONF_SIGNALLING_SHIFT;
+
+               /* Cable Type */
+               if (cable_tbt_vdo & TBT_CABLE_OPTICAL)
+                       dp_data.conf |= DP_CONF_CABLE_TYPE_OPTICAL << DP_CONF_CABLE_TYPE_SHIFT;
+               else if (cable_tbt_vdo & TBT_CABLE_RETIMER)
+                       dp_data.conf |= DP_CONF_CABLE_TYPE_RE_TIMER << DP_CONF_CABLE_TYPE_SHIFT;
+               else if (cable_tbt_vdo & TBT_CABLE_ACTIVE_PASSIVE)
+                       dp_data.conf |= DP_CONF_CABLE_TYPE_RE_DRIVER << DP_CONF_CABLE_TYPE_SHIFT;
+       } else if (PD_IDH_PTYPE(port->c_identity.id_header) == IDH_PTYPE_PCABLE) {
+               dp_data.conf |= VDO_TYPEC_CABLE_SPEED(port->c_identity.vdo[0]) <<
+                               DP_CONF_SIGNALLING_SHIFT;
+       }
+
        ret = cros_typec_retimer_set(port->retimer, port->state);
        if (!ret)
                ret = typec_mux_set(port->mux, &port->state);