TCPMV2: Add support for sending Alert Messages

Add support for sending Alert OVC and OVP messages

BRANCH=none
BUG=b:117854867
TEST=make -j buildall

Signed-off-by: Sam Hurst <shurst@google.com>
Change-Id: Ia436c8869880897ea9af0c2c2b0d6e9288831a8f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2229285
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>

common/usb_common.c

@@ -792,3 +792,23 @@ static int command_tcpc_dump(int argc, char **argv)
 DECLARE_CONSOLE_COMMAND(tcpci_dump, command_tcpc_dump, "<Type-C port>",
 			"dump the TCPC regs");
 #endif /* defined(CONFIG_CMD_TCPC_DUMP) */
+
+int pd_build_alert_msg(uint32_t *msg, uint32_t *len, enum pd_power_role pr)
+{
+	if (msg == NULL || len == NULL)
+		return EC_ERROR_INVAL;
+
+	/*
+	 * SOURCE: currently only supports OCP
+	 * SINK:   currently only supports OVP
+	 */
+	if (pr == PD_ROLE_SOURCE)
+		*msg = ADO_OCP_EVENT;
+	else
+		*msg = ADO_OVP_EVENT;
+
+	/* Alert data is 4 bytes */
+	*len = 4;
+
+	return EC_SUCCESS;
+}

common/usbc/usb_pe_drp_sm.c

@@ -250,6 +250,7 @@ enum usb_pe_state {
 	PE_FRS_SNK_SRC_START_AMS,
 	PE_GIVE_BATTERY_CAP,
 	PE_GIVE_BATTERY_STATUS,
+	PE_SEND_ALERT,
 
 #ifdef CONFIG_USB_PD_REV30
 	/* Super States */
@@ -342,6 +343,7 @@ static const char * const pe_state_names[] = {
 	[PE_FRS_SNK_SRC_START_AMS] = "PE_FRS_SNK_SRC_Start_Ams",
 	[PE_GIVE_BATTERY_CAP] = "PE_Give_Battery_Cap",
 	[PE_GIVE_BATTERY_STATUS] = "PE_Give_Battery_Status",
+	[PE_SEND_ALERT] = "PE_Send_Alert",
 
 	/* Super States */
 	[PE_PRS_FRS_SHARED] = "SS:PE_PRS_FRS_SHARED",
@@ -1093,7 +1095,12 @@ test_export_static enum usb_pe_state get_state_pe(const int port)
 
 static bool common_src_snk_dpm_requests(int port)
 {
-	if (IS_ENABLED(CONFIG_USBC_VCONN) &&
+	if (IS_ENABLED(CONFIG_USB_PD_REV30) &&
+			PE_CHK_DPM_REQUEST(port, DPM_REQUEST_SEND_ALERT)) {
+		PE_CLR_DPM_REQUEST(port, DPM_REQUEST_SEND_ALERT);
+		set_state_pe(port, PE_SEND_ALERT);
+		return true;
+	} else if (IS_ENABLED(CONFIG_USBC_VCONN) &&
 			PE_CHK_DPM_REQUEST(port, DPM_REQUEST_VCONN_SWAP)) {
 		PE_CLR_DPM_REQUEST(port, DPM_REQUEST_VCONN_SWAP);
 		set_state_pe(port, PE_VCS_SEND_SWAP);
@@ -3276,6 +3283,39 @@ static void pe_give_battery_status_run(int port)
 		set_state_pe(port, PE_SRC_READY);
 	}
 }
+
+/**
+ * PE_SRC_Send_Source_Alert and
+ * PE_SNK_Send_Sink_Alert
+ */
+static void pe_send_alert_entry(int port)
+{
+	uint32_t *msg = (uint32_t *)tx_emsg[port].buf;
+	uint32_t *len = &tx_emsg[port].len;
+
+	print_current_state(port);
+
+	if (pd_build_alert_msg(msg, len, pe[port].power_role) != EC_SUCCESS) {
+		if (pe[port].power_role == PD_ROLE_SOURCE)
+			set_state_pe(port, PE_SRC_READY);
+		else
+			set_state_pe(port, PE_SNK_READY);
+	}
+
+	/* Request the Protocol Layer to send Alert Message. */
+	send_data_msg(port, TCPC_TX_SOP, PD_DATA_ALERT);
+}
+
+static void pe_send_alert_run(int port)
+{
+	if (PE_CHK_FLAG(port, PE_FLAGS_TX_COMPLETE)) {
+		PE_CLR_FLAG(port, PE_FLAGS_TX_COMPLETE);
+		if (pe[port].power_role == PD_ROLE_SOURCE)
+			set_state_pe(port, PE_SRC_READY);
+		else
+			set_state_pe(port, PE_SNK_READY);
+	}
+}
 #endif /* CONFIG_USB_PD_REV30 */
 
 /**
@@ -5579,6 +5619,10 @@ static const struct usb_state pe_states[] = {
 		.entry = pe_give_battery_status_entry,
 		.run   = pe_give_battery_status_run,
 	},
+	[PE_SEND_ALERT] = {
+		.entry = pe_send_alert_entry,
+		.run   = pe_send_alert_run,
+	},
 #endif /* CONFIG_USB_PD_REV30 */
 	[PE_DRS_EVALUATE_SWAP] = {
 		.entry = pe_drs_evaluate_swap_entry,

include/usb_common.h

@@ -179,4 +179,14 @@ int pd_get_saved_port_flags(int port, uint8_t *flags);
  * @param do_set value written to the BB Ram flag
  */
 void pd_update_saved_port_flags(int port, uint8_t flag, uint8_t do_set);
+
+/**
+ * Build PD alert message
+ *
+ * @param msg pointer where message is stored
+ * @param len pointer where length of message is stored in bytes
+ * @param pr  current PD power role
+ * @return EC_SUCCESS on success else EC_ERROR_INVAL
+ */
+int pd_build_alert_msg(uint32_t *msg, uint32_t *len, enum pd_power_role pr);
 #endif /* __CROS_EC_USB_COMMON_H */

include/usb_pd.h

@@ -1096,6 +1096,16 @@ enum pd_ext_msg_type {
 	/* 15-31 Reserved */
 };
 
+/* Alert Data Object fields for REV 3.0 */
+#define ADO_OVP_EVENT                   BIT(30)
+#define ADO_SOURCE_INPUT_CHANGE         BIT(29)
+#define ADO_OPERATING_CONDITION_CHANGE  BIT(28)
+#define ADO_OTP_EVENT                   BIT(27)
+#define ADO_OCP_EVENT                   BIT(26)
+#define ADO_BATTERY_STATUS_CHANGE       BIT(25)
+#define ADO_FIXED_BATTERIES(n)          ((n & 0xf) << 20)
+#define ADO_HOT_SWAPPABLE_BATTERIES(n)  ((n & 0xf) << 16)
+
 /* Data message type */
 enum pd_data_msg_type {
 	/* 0 Reserved */

include/usb_pe_sm.h

@@ -42,6 +42,7 @@ enum pe_dpm_request {
 	DPM_REQUEST_HARD_RESET_SEND     = BIT(15),
 	DPM_REQUEST_SOFT_RESET_SEND     = BIT(16),
 	DPM_REQUEST_PORT_DISCOVERY      = BIT(17),
+	DPM_REQUEST_SEND_ALERT          = BIT(18),
 };
 
 /**