[PATCH] platform/chrome: cros_ec_typec: USB4 support

[Heikki Krogerus]

With USB4 mode the mux driver needs the Enter_USB Data
Object (EUDO) that was used when the USB mode was entered.
Though the object is not available in the driver, it is
possible to construct it from the information we have.

Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
---
Hi,

This patch depends on latest usb-next from Greg KH, this commit in
particular:
https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/commit/?h=usb-next&id=ad8db94d6813dc659bd4de0531a8a1150559eafb

Prashant, can you take over the development of this patch (in case it
still needs work)? I will take a few weeks vacation starting from next
week (July 6th). I was hoping to get this feature into v5.9 if that's
possible. But if you guys think there is no hurry, let's forget about
it. Then we can just wait for 5.9-rc1 and not worry about the
dependency on Greg's usb-next.

thanks,

---
 drivers/platform/chrome/cros_ec_typec.c | 42 ++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 0c041b79cbbac..c9713aab9b6b0 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -13,6 +13,7 @@
 #include <linux/platform_data/cros_ec_proto.h>
 #include <linux/platform_data/cros_usbpd_notify.h>
 #include <linux/platform_device.h>
+#include <linux/usb/pd.h>
 #include <linux/usb/typec.h>
 #include <linux/usb/typec_altmode.h>
 #include <linux/usb/typec_dp.h>
@@ -494,6 +495,43 @@ static int cros_typec_enable_dp(struct cros_typec_data *typec,
 	return typec_mux_set(port->mux, &port->state);
 }
 
+static int cros_typec_enable_usb4(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 enter_usb_data data;
+
+	data.eudo = EUDO_USB_MODE_USB4 << EUDO_USB_MODE_SHIFT;
+
+	/* Cable Speed */
+	data.eudo |= pd_ctrl->cable_speed << EUDO_CABLE_SPEED_SHIFT;
+
+	/* Cable Type */
+	if (pd_ctrl->control_flags & USB_PD_CTRL_OPTICAL_CABLE)
+		data.eudo |= EUDO_CABLE_TYPE_OPTICAL << EUDO_CABLE_TYPE_SHIFT;
+	else if (pd_ctrl->control_flags & USB_PD_CTRL_ACTIVE_CABLE)
+		data.eudo |= EUDO_CABLE_TYPE_RE_TIMER << EUDO_CABLE_TYPE_SHIFT;
+
+	/* REVISIT: Cable Current? */
+
+	/* REVISIT: Claiming unconditionally that all tunnels are supported. */
+	data.eudo |= EUDO_PCIE_SUPPORT;
+	data.eudo |= EUDO_DP_SUPPORT;
+
+	data.eudo |= EUDO_TBT_SUPPORT;
+	data.eudo |= EUDO_HOST_PRESENT;
+
+	data.active_link_training = !!(pd_ctrl->control_flags &
+				       USB_PD_CTRL_ACTIVE_LINK_UNIDIR);
+
+	port->state.alt = NULL;
+	port->state.data = &data;
+	port->state.mode = TYPEC_MODE_USB4;
+
+	return typec_mux_set(port->mux, &port->state);
+}
+
 static int cros_typec_configure_mux(struct cros_typec_data *typec, int port_num,
 				uint8_t mux_flags,
 				struct ec_response_usb_pd_control_v2 *pd_ctrl)
@@ -514,7 +552,9 @@ static int cros_typec_configure_mux(struct cros_typec_data *typec, int port_num,
 	if (ret)
 		return ret;
 
-	if (mux_flags & USB_PD_MUX_TBT_COMPAT_ENABLED) {
+	if (mux_flags & USB_PD_MUX_USB4_ENABLED) {
+		ret = cros_typec_enable_usb4(typec, port_num, pd_ctrl);
+	} else 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);
-- 
2.27.0