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Date: Fri, 23 Feb 2024 01:03:27 +0000
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Subject: [PATCH 3/4] usb: typec: ucsi: Register SOP/SOP' Discover Identity Responses
From: Jameson Thies <jthies@google.com>
To: heikki.krogerus@linux.intel.com, linux-usb@vger.kernel.org
Cc: jthies@google.com, pmalani@chromium.org, bleung@google.com, 
	abhishekpandit@chromium.org, andersson@kernel.org, 
	dmitry.baryshkov@linaro.org, fabrice.gasnier@foss.st.com, 
	gregkh@linuxfoundation.org, hdegoede@redhat.com, neil.armstrong@linaro.org, 
	rajaram.regupathy@intel.com, saranya.gopal@intel.com, 
	linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"

Register SOP and SOP' Discover Identity responses with the USB Type-C
Connector Class as partner and cable identities, respectively. Discover
Identity responses are requested from the PPM using the GET_PD_MESSAGE
UCSI command.

Signed-off-by: Jameson Thies <jthies@google.com>
---
Tested on v6.6 kernel. GET_PD_MESSAGE responses from the PPM populate
partner and cable identity in sysfs.
redrix-rev3 /sys/class/typec # ls port2-partner/identity/
cert_stat  id_header  product  product_type_vdo1  product_type_vdo2
product_type_vdo3
redrix-rev3 /sys/class/typec # ls port2-cable/identity/
cert_stat  id_header  product  product_type_vdo1  product_type_vdo2
product_type_vdo3

 drivers/usb/typec/ucsi/ucsi.c | 77 +++++++++++++++++++++++++++++++++++
 drivers/usb/typec/ucsi/ucsi.h | 29 +++++++++++++
 2 files changed, 106 insertions(+)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 15e82f5fab37..6d6443e61faa 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -646,6 +646,73 @@ static int ucsi_get_src_pdos(struct ucsi_connector *con)
 	return ret;
 }
 
+static int ucsi_read_identity(struct ucsi_connector *con, u8 recipient, struct usb_pd_identity *id)
+{
+	struct ucsi *ucsi = con->ucsi;
+	struct ucsi_pd_message_disc_id resp = {};
+	u64 command;
+	int ret;
+
+	/*
+	 * Skip identity discovery and registration if UCSI version is less than
+	 * v2.0. Before v2.0 MESSAGE_IN is 16 bytes which cannot fit a complete
+	 * 24 byte identity response.
+	 */
+	if (ucsi->version < UCSI_VERSION_2_0)
+		return -EPROTO;
+
+	command = UCSI_COMMAND(UCSI_GET_PD_MESSAGE) | UCSI_CONNECTOR_NUMBER(con->num);
+	command |= UCSI_GET_PD_MESSAGE_RECIPIENT(recipient);
+	/* VDM Header + 6 VDOs (0x1c bytes) without an offset */
+	command |= UCSI_GET_PD_MESSAGE_OFFSET(0);
+	command |= UCSI_GET_PD_MESSAGE_BYTES(0x1c);
+	command |= UCSI_GET_PD_MESSAGE_TYPE(UCSI_GET_PD_MESSAGE_TYPE_IDENTITY);
+
+	ret = ucsi_send_command(ucsi, command, &resp, sizeof(resp));
+	if (ret < 0) {
+		dev_err(ucsi->dev, "UCSI_GET_PD_MESSAGE failed (%d)\n", ret);
+		return ret;
+	}
+
+	id->id_header = resp.id_header;
+	id->cert_stat = resp.cert_stat;
+	id->product = resp.product;
+	id->vdo[0] = resp.vdo[0];
+	id->vdo[1] = resp.vdo[1];
+	id->vdo[2] = resp.vdo[2];
+	return 0;
+}
+
+static int ucsi_get_partner_identity(struct ucsi_connector *con)
+{
+	int ret;
+
+	ret = ucsi_read_identity(con, UCSI_RECIPIENT_SOP, &con->partner_identity);
+	if (ret < 0)
+		return ret;
+
+	ret = typec_partner_set_identity(con->partner);
+	if (ret < 0)
+		dev_err(con->ucsi->dev, "Failed to set partner identity (%d)\n", ret);
+
+	return ret;
+}
+
+static int ucsi_get_cable_identity(struct ucsi_connector *con)
+{
+	int ret;
+
+	ret = ucsi_read_identity(con, UCSI_RECIPIENT_SOP_P, &con->cable_identity);
+	if (ret < 0)
+		return ret;
+
+	ret = typec_cable_set_identity(con->cable);
+	if (ret < 0)
+		dev_err(con->ucsi->dev, "Failed to set cable identity (%d)\n", ret);
+
+	return ret;
+}
+
 static int ucsi_check_altmodes(struct ucsi_connector *con)
 {
 	int ret, num_partner_am;
@@ -754,6 +821,7 @@ static int ucsi_register_cable(struct ucsi_connector *con)
 		break;
 	}
 
+	desc.identity = &con->cable_identity;
 	desc.active = !!(UCSI_CABLE_PROP_FLAG_ACTIVE_CABLE & con->cable_prop.flags);
 	desc.pd_revision = UCSI_CABLE_PROP_FLAG_PD_MAJOR_REV_AS_BCD(con->cable_prop.flags);
 
@@ -776,6 +844,7 @@ static void ucsi_unregister_cable(struct ucsi_connector *con)
 
 	typec_unregister_cable(con->cable);
 	con->cable = NULL;
+	memset(&con->cable_identity, 0, sizeof(con->cable_identity));
 }
 
 static void ucsi_pwr_opmode_change(struct ucsi_connector *con)
@@ -825,6 +894,7 @@ static int ucsi_register_partner(struct ucsi_connector *con)
 		break;
 	}
 
+	desc.identity = &con->partner_identity;
 	desc.usb_pd = pwr_opmode == UCSI_CONSTAT_PWR_OPMODE_PD;
 	desc.pd_revision = UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags);
 
@@ -854,6 +924,7 @@ static void ucsi_unregister_partner(struct ucsi_connector *con)
 	ucsi_unregister_cable(con);
 	typec_unregister_partner(con->partner);
 	con->partner = NULL;
+	memset(&con->partner_identity, 0, sizeof(con->partner_identity));
 }
 
 static void ucsi_partner_change(struct ucsi_connector *con)
@@ -971,6 +1042,10 @@ static int ucsi_check_cable(struct ucsi_connector *con)
 	if (ret < 0)
 		return ret;
 
+	ret = ucsi_get_cable_identity(con);
+	if (ret < 0)
+		return ret;
+
 	return 0;
 }
 
@@ -1015,6 +1090,7 @@ static void ucsi_handle_connector_change(struct work_struct *work)
 			ucsi_register_partner(con);
 			ucsi_partner_task(con, ucsi_check_connection, 1, HZ);
 			ucsi_partner_task(con, ucsi_check_connector_capability, 1, HZ);
+			ucsi_partner_task(con, ucsi_get_partner_identity, 1, HZ);
 			ucsi_partner_task(con, ucsi_check_cable, 1, HZ);
 
 			if (UCSI_CONSTAT_PWR_OPMODE(con->status.flags) ==
@@ -1414,6 +1490,7 @@ static int ucsi_register_port(struct ucsi *ucsi, struct ucsi_connector *con)
 		ucsi_register_partner(con);
 		ucsi_pwr_opmode_change(con);
 		ucsi_port_psy_changed(con);
+		ucsi_get_partner_identity(con);
 		ucsi_check_cable(con);
 	}
 
diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index f0aabef0b7c6..b89fae82e8ce 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -106,6 +106,7 @@ void ucsi_connector_change(struct ucsi *ucsi, u8 num);
 #define UCSI_GET_CABLE_PROPERTY		0x11
 #define UCSI_GET_CONNECTOR_STATUS	0x12
 #define UCSI_GET_ERROR_STATUS		0x13
+#define UCSI_GET_PD_MESSAGE		0x15
 
 #define UCSI_CONNECTOR_NUMBER(_num_)		((u64)(_num_) << 16)
 #define UCSI_COMMAND(_cmd_)			((_cmd_) & 0xff)
@@ -159,6 +160,18 @@ void ucsi_connector_change(struct ucsi *ucsi, u8 num);
 #define UCSI_MAX_PDOS				(4)
 #define UCSI_GET_PDOS_SRC_PDOS			((u64)1 << 34)
 
+/* GET_PD_MESSAGE command bits */
+#define UCSI_GET_PD_MESSAGE_RECIPIENT(_r_)	((u64)(_r_) << 23)
+#define UCSI_GET_PD_MESSAGE_OFFSET(_r_)		((u64)(_r_) << 26)
+#define UCSI_GET_PD_MESSAGE_BYTES(_r_)		((u64)(_r_) << 34)
+#define UCSI_GET_PD_MESSAGE_TYPE(_r_)		((u64)(_r_) << 42)
+#define   UCSI_GET_PD_MESSAGE_TYPE_SNK_CAP_EXT	0
+#define   UCSI_GET_PD_MESSAGE_TYPE_SRC_CAP_EXT	1
+#define   UCSI_GET_PD_MESSAGE_TYPE_BAT_CAP	2
+#define   UCSI_GET_PD_MESSAGE_TYPE_BAT_STAT	3
+#define   UCSI_GET_PD_MESSAGE_TYPE_IDENTITY	4
+#define   UCSI_GET_PD_MESSAGE_TYPE_REVISION	5
+
 /* -------------------------------------------------------------------------- */
 
 /* Error information returned by PPM in response to GET_ERROR_STATUS command. */
@@ -338,6 +351,18 @@ struct ucsi_connector_status {
 	((get_unaligned_le32(&(_p_)[5]) & GENMASK(16, 1)) >> 1)
 } __packed;
 
+/*
+ * Data structure filled by PPM in response to GET_PD_MESSAGE command with the
+ * Response Message Type set to Discover Identity Response.
+ */
+struct ucsi_pd_message_disc_id {
+	u32 vdm_header;
+	u32 id_header;
+	u32 cert_stat;
+	u32 product;
+	u32 vdo[3];
+} __packed;
+
 /* -------------------------------------------------------------------------- */
 
 struct ucsi_debugfs_entry {
@@ -428,6 +453,10 @@ struct ucsi_connector {
 	struct usb_power_delivery_capabilities *partner_sink_caps;
 
 	struct usb_role_switch *usb_role_sw;
+
+	/* USB PD identity */
+	struct usb_pd_identity partner_identity;
+	struct usb_pd_identity cable_identity;
 };
 
 int ucsi_send_command(struct ucsi *ucsi, u64 command,
-- 
2.44.0.rc0.258.g7320e95886-goog