[PATCH v2 6/7] platform/chrome: cros_ec_typec: Thunderbolt support

Abhishek Pandit-Subedi
2024-10-30T21:29:15Z

Add support for entering and exiting Thunderbolt alt-mode using AP
driven alt-mode.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v2:
- Refactored thunderbolt support into cros_typec_altmode.c

drivers/platform/chrome/cros_ec_typec.c | 29 ++++---
drivers/platform/chrome/cros_typec_altmode.c | 85 ++++++++++++++++++++
drivers/platform/chrome/cros_typec_altmode.h | 14 ++++
3 files changed, 116 insertions(+), 12 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 7997e7136c4c..3e043b1c1cc8 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -304,21 +304,26 @@ static int cros_typec_register_port_altmodes(struct cros_typec_data *typec,
typec_altmode_set_drvdata(amode, port);
amode->ops = &port_amode_ops;
#endif
-
/*
* 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.
+ * if it doesn't support it and it will not enter automatically by
+ * design so we can use the |ap_driven_altmode| feature to check if we
+ * should register it.
*/
- memset(&desc, 0, sizeof(desc));
- desc.svid = USB_TYPEC_TBT_SID;
- desc.mode = TYPEC_ANY_MODE;
- amode = typec_port_register_altmode(port->port, &desc);
- if (IS_ERR(amode))
- return PTR_ERR(amode);
- port->port_altmode[CROS_EC_ALTMODE_TBT] = amode;
- typec_altmode_set_drvdata(amode, port);
- amode->ops = &port_amode_ops;
+ if (typec->ap_driven_altmode) {
+ memset(&desc, 0, sizeof(desc));
+ desc.svid = USB_TYPEC_TBT_SID;
+ desc.mode = TYPEC_ANY_MODE;
+ amode = cros_typec_register_thunderbolt(port, &desc);
+ if (IS_ERR(amode))
+ return PTR_ERR(amode);
+ port->port_altmode[CROS_EC_ALTMODE_TBT] = amode;
+
+#if !IS_ENABLED(CONFIG_TYPEC_TBT_ALTMODE)
+ typec_altmode_set_drvdata(amode, port);
+ amode->ops = &port_amode_ops;
+#endif
+ }

port->state.alt = NULL;
port->state.mode = TYPEC_STATE_USB;
diff --git a/drivers/platform/chrome/cros_typec_altmode.c b/drivers/platform/chrome/cros_typec_altmode.c
index af2f077674f1..6cb1e1320d6c 100644
--- a/drivers/platform/chrome/cros_typec_altmode.c
+++ b/drivers/platform/chrome/cros_typec_altmode.c
@@ -8,6 +8,7 @@
#include "cros_ec_typec.h"

#include <linux/usb/typec_dp.h>
+#include <linux/usb/typec_tbt.h>
#include <linux/usb/pd_vdo.h>

#include "cros_typec_altmode.h"
@@ -71,6 +72,8 @@ static int cros_typec_altmode_enter(struct typec_altmode *alt, u32 *vdo)

if (data->sid == USB_TYPEC_DP_SID)
req.mode_to_enter = CROS_EC_ALTMODE_DP;
+ else if (data->sid == USB_TYPEC_TBT_SID)
+ req.mode_to_enter = CROS_EC_ALTMODE_TBT;
else
return -EOPNOTSUPP;

@@ -198,6 +201,53 @@ static int cros_typec_displayport_vdm(struct typec_altmode *alt, u32 header,
return 0;
}

+static int cros_typec_thunderbolt_vdm(struct typec_altmode *alt, u32 header,
+ const u32 *data, int count)
+{
+ struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
+
+ int cmd_type = PD_VDO_CMDT(header);
+ int cmd = PD_VDO_CMD(header);
+ int svdm_version;
+
+ svdm_version = typec_altmode_get_svdm_version(alt);
+ if (svdm_version < 0)
+ return svdm_version;
+
+ switch (cmd_type) {
+ case CMDT_INIT:
+ if (PD_VDO_SVDM_VER(header) < svdm_version) {
+ typec_partner_set_svdm_version(adata->port->partner,
+ PD_VDO_SVDM_VER(header));
+ svdm_version = PD_VDO_SVDM_VER(header);
+ }
+
+ adata->header = VDO(USB_TYPEC_TBT_SID, 1, svdm_version, cmd);
+ adata->header |= VDO_OPOS(USB_TYPEC_TBT_MODE);
+
+ switch (cmd) {
+ case CMD_ENTER_MODE:
+ /* Don't respond to the enter mode vdm because it
+ * triggers mux configuration. This is handled directly
+ * by the cros_ec_typec driver so the Thunderbolt driver
+ * doesn't need to be involved.
+ */
+ break;
+ default:
+ adata->header |= VDO_CMDT(CMDT_RSP_ACK);
+ schedule_work(&adata->work);
+ break;
+ }
+
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+
static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
const u32 *data, int count)
{
@@ -206,6 +256,9 @@ static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
if (adata->sid == USB_TYPEC_DP_SID)
return cros_typec_displayport_vdm(alt, header, data, count);

+ if (adata->sid == USB_TYPEC_TBT_SID)
+ return cros_typec_thunderbolt_vdm(alt, header, data, count);
+
return -EINVAL;
}

@@ -275,3 +328,35 @@ cros_typec_register_displayport(struct cros_typec_port *port,
return alt;
}
#endif
+
+#if IS_ENABLED(CONFIG_TYPEC_TBT_ALTMODE)
+struct typec_altmode *
+cros_typec_register_thunderbolt(struct cros_typec_port *port,
+ struct typec_altmode_desc *desc)
+{
+ struct typec_altmode *alt;
+ struct cros_typec_altmode_data *data;
+
+ alt = typec_port_register_altmode(port->port, desc);
+ if (IS_ERR(alt))
+ return alt;
+
+ data = devm_kzalloc(&alt->dev, sizeof(*data), GFP_KERNEL);
+ if (!data) {
+ typec_unregister_altmode(alt);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ INIT_WORK(&data->work, cros_typec_altmode_work);
+ data->alt = alt;
+ data->port = port;
+ data->ap_mode_entry = true;
+ data->sid = USB_TYPEC_TBT_SID;
+ data->mode = USB_TYPEC_TBT_MODE;
+
+ typec_altmode_set_ops(alt, &cros_typec_altmode_ops);
+ typec_altmode_set_drvdata(alt, data);
+
+ return alt;
+}
+#endif
diff --git a/drivers/platform/chrome/cros_typec_altmode.h b/drivers/platform/chrome/cros_typec_altmode.h
index c6f8fb02c99c..c71568314e3f 100644
--- a/drivers/platform/chrome/cros_typec_altmode.h
+++ b/drivers/platform/chrome/cros_typec_altmode.h
@@ -31,4 +31,18 @@ static inline int cros_typec_displayport_status_update(struct typec_altmode *alt
return 0;
}
#endif
+
+#if IS_ENABLED(CONFIG_TYPEC_TBT_ALTMODE)
+struct typec_altmode *
+cros_typec_register_thunderbolt(struct cros_typec_port *port,
+ struct typec_altmode_desc *desc);
+#else
+struct typec_altmode *
+cros_typec_register_thunderbolt(struct cros_typec_port *port,
+ struct typec_altmode_desc *desc)
+{
+ return typec_port_register_altmode(port->port, desc);
+}
+#endif
+
#endif /* __CROS_TYPEC_ALTMODE_H__ */
--
2.47.0.163.g1226f6d8fa-goog