platform/chrome: cros_ec_typec: Add TBT compat support

Add mux control support for Thunderbolt compatibility mode.

Suggested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Co-developed-by: Azhar Shaikh <azhar.shaikh@intel.com>
Co-developed-by: Casey Bowman <casey.g.bowman@intel.com>
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 1df1386..0c041b7 100644 (file)
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -17,6 +17,7 @@
 #include <linux/usb/typec_altmode.h>
 #include <linux/usb/typec_dp.h>
 #include <linux/usb/typec_mux.h>
+#include <linux/usb/typec_tbt.h>
 #include <linux/usb/role.h>
 
 #define DRV_NAME "cros-ec-typec"
@@ -24,6 +25,7 @@
 /* Supported alt modes. */
 enum {
        CROS_EC_ALTMODE_DP = 0,
+       CROS_EC_ALTMODE_TBT,
        CROS_EC_ALTMODE_MAX,
 };
 
@@ -165,6 +167,14 @@ static void cros_typec_register_port_altmodes(struct cros_typec_data *typec,
        port->p_altmode[CROS_EC_ALTMODE_DP].svid = USB_TYPEC_DP_SID;
        port->p_altmode[CROS_EC_ALTMODE_DP].mode = USB_TYPEC_DP_MODE;
 
+       /*
+        * Register TBT compatibility alt mode. The EC will not enter the mode
+        * if it doesn't support it, so it's safe to register it unconditionally
+        * here for now.
+        */
+       port->p_altmode[CROS_EC_ALTMODE_TBT].svid = USB_TYPEC_TBT_SID;
+       port->p_altmode[CROS_EC_ALTMODE_TBT].mode = TYPEC_ANY_MODE;
+
        port->state.alt = NULL;
        port->state.mode = TYPEC_STATE_USB;
        port->state.data = NULL;
@@ -391,6 +401,62 @@ static int cros_typec_usb_safe_state(struct cros_typec_port *port)
        return typec_mux_set(port->mux, &port->state);
 }
 
+/*
+ * Spoof the VDOs that were likely communicated by the partner for TBT alt
+ * mode.
+ */
+static int cros_typec_enable_tbt(struct cros_typec_data *typec,
+                                int port_num,
+                                struct ec_response_usb_pd_control_v2 *pd_ctrl)
+{
+       struct cros_typec_port *port = typec->ports[port_num];
+       struct typec_thunderbolt_data data;
+       int ret;
+
+       if (typec->pd_ctrl_ver < 2) {
+               dev_err(typec->dev,
+                       "PD_CTRL version too old: %d\n", typec->pd_ctrl_ver);
+               return -ENOTSUPP;
+       }
+
+       /* Device Discover Mode VDO */
+       data.device_mode = TBT_MODE;
+
+       if (pd_ctrl->control_flags & USB_PD_CTRL_TBT_LEGACY_ADAPTER)
+               data.device_mode = TBT_SET_ADAPTER(TBT_ADAPTER_TBT3);
+
+       /* Cable Discover Mode VDO */
+       data.cable_mode = TBT_MODE;
+       data.cable_mode |= TBT_SET_CABLE_SPEED(pd_ctrl->cable_speed);
+
+       if (pd_ctrl->control_flags & USB_PD_CTRL_OPTICAL_CABLE)
+               data.cable_mode |= TBT_CABLE_OPTICAL;
+
+       if (pd_ctrl->control_flags & USB_PD_CTRL_ACTIVE_LINK_UNIDIR)
+               data.cable_mode |= TBT_CABLE_LINK_TRAINING;
+
+       if (pd_ctrl->cable_gen)
+               data.cable_mode |= TBT_CABLE_ROUNDED;
+
+       /* Enter Mode VDO */
+       data.enter_vdo = TBT_SET_CABLE_SPEED(pd_ctrl->cable_speed);
+
+       if (pd_ctrl->control_flags & USB_PD_CTRL_ACTIVE_CABLE)
+               data.enter_vdo |= TBT_ENTER_MODE_ACTIVE_CABLE;
+
+       if (!port->state.alt) {
+               port->state.alt = &port->p_altmode[CROS_EC_ALTMODE_TBT];
+               ret = cros_typec_usb_safe_state(port);
+               if (ret)
+                       return ret;
+       }
+
+       port->state.data = &data;
+       port->state.mode = TYPEC_TBT_MODE;
+
+       return typec_mux_set(port->mux, &port->state);
+}
+
 /* Spoof the VDOs that were likely communicated by the partner. */
 static int cros_typec_enable_dp(struct cros_typec_data *typec,
                                int port_num,
@@ -448,7 +514,9 @@ static int cros_typec_configure_mux(struct cros_typec_data *typec, int port_num,
        if (ret)
                return ret;
 
-       if (mux_flags & USB_PD_MUX_DP_ENABLED) {
+       if (mux_flags & USB_PD_MUX_TBT_COMPAT_ENABLED) {
+               ret = cros_typec_enable_tbt(typec, port_num, pd_ctrl);
+       } else if (mux_flags & USB_PD_MUX_DP_ENABLED) {
                ret = cros_typec_enable_dp(typec, port_num, pd_ctrl);
        } else if (mux_flags & USB_PD_MUX_SAFE_MODE) {
                ret = cros_typec_usb_safe_state(port);