TCPMv2: Add common exit mode for all the alternate modes

When chipset is transitioning to a new state or on sysjump, the SOC
re-negotiates to enter an alternate mode on booting up.

This commit:
1. Adds a common DPM function to check for all the active alternate modes
   one at a time, construct the VDM and send the DPM request to exit the
   mode.
2. Marks thunderbolt mode as inactive in DFP's thunderbolt mode exit
   function.

BUG=b:152235216
BRANCH=None
TEST=Tested on volteer:
     1. On connecting a DP dongle, able to enter into DP alternate mode
        on reboot
     2. On connecting a Thunderbolt dock, able to enter into Thunderbolt
        mode on reboot

Change-Id: I7da6a4b08cab9abb3446c0dafdc7c9e9378ef00e
Signed-off-by: Ayushee <ayushee.shah@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2270877
Tested-by: Abe Levkoy <alevkoy@chromium.org>
Reviewed-by: Abe Levkoy <alevkoy@chromium.org>
Commit-Queue: Abe Levkoy <alevkoy@chromium.org>

5 files changed, 84 insertions, 56 deletions

diff --git a/common/usbc/dp_alt_mode.c b/common/usbc/dp_alt_mode.c
index 569c64d7ca..cc5305c0c3 100644
--- a/common/usbc/dp_alt_mode.c
+++ b/common/usbc/dp_alt_mode.c
@@ -51,6 +51,11 @@ static const uint8_t state_vdm_cmd[DP_STATE_COUNT] = {
 	[DP_ENTER_RETRY] = CMD_ENTER_MODE,
 };
 
+bool dp_is_active(int port)
+{
+	return dp_state[port] == DP_ACTIVE;
+}
+
 void dp_init(int port)
 {
 	dp_state[port] = DP_START;
diff --git a/common/usbc/tbt_alt_mode.c b/common/usbc/tbt_alt_mode.c
index 57b0da41b8..ee4c78285e 100644
--- a/common/usbc/tbt_alt_mode.c
+++ b/common/usbc/tbt_alt_mode.c
@@ -56,6 +56,11 @@ void tbt_init(int port)
 	tbt_state[port] = TBT_START;
 }
 
+bool tbt_is_active(int port)
+{
+	return tbt_state[port] == TBT_ACTIVE;
+}
+
 void tbt_teardown(int port)
 {
 	 tbt_prints("teardown", port);
diff --git a/common/usbc/usb_pd_dpm.c b/common/usbc/usb_pd_dpm.c
index 9a79aeaa10..e2f2c4d356 100644
--- a/common/usbc/usb_pd_dpm.c
+++ b/common/usbc/usb_pd_dpm.c
@@ -29,11 +29,13 @@
 
 static struct {
 	bool mode_entry_done;
+	bool mode_exit_request;
 } dpm[CONFIG_USB_PD_PORT_MAX_COUNT];
 
 void dpm_init(int port)
 {
 	dpm[port].mode_entry_done = false;
+	dpm[port].mode_exit_request = false;
 }
 
 void dpm_set_mode_entry_done(int port)
@@ -41,6 +43,16 @@ void dpm_set_mode_entry_done(int port)
 	dpm[port].mode_entry_done = true;
 }
 
+void dpm_set_mode_exit_request(int port)
+{
+	dpm[port].mode_exit_request = true;
+}
+
+static inline void dpm_clear_mode_exit_request(int port)
+{
+	dpm[port].mode_exit_request = false;
+}
+
 void dpm_vdm_acked(int port, enum tcpm_transmit_type type, int vdo_count,
 		uint32_t *vdm)
 {
@@ -159,3 +171,46 @@ void dpm_attempt_mode_entry(int port)
 
 	pe_dpm_request(port, DPM_REQUEST_VDM);
 }
+
+void dpm_attempt_mode_exit(int port)
+{
+	int opos;
+	uint16_t svid;
+	uint32_t vdm;
+
+	if (!dpm[port].mode_exit_request)
+		return;
+
+	/* TODO: Add exit mode support for SOP' and SOP'' */
+
+	if (IS_ENABLED(CONFIG_USB_PD_TBT_COMPAT_MODE) &&
+	    tbt_is_active(port))
+		svid = USB_VID_INTEL;
+	else if (dp_is_active(port))
+		svid = USB_SID_DISPLAYPORT;
+	else {
+		/* Clear exit mode request */
+		dpm_clear_mode_exit_request(port);
+		return;
+	}
+
+	opos = pd_alt_mode(port, TCPC_TX_SOP, svid);
+	if (opos > 0 && pd_dfp_exit_mode(port, TCPC_TX_SOP, svid, opos)) {
+		/*
+		 * TODO b/159717794: Delay deleting the data until after the
+		 * EXIT_MODE message is has ACKed. Unfortunately the callers
+		 * of this function expect the mode to be cleaned up before
+		 * return.
+		 */
+		vdm = VDO(svid, 1, /* Structured */
+			  VDO_SVDM_VERS(pd_get_vdo_ver(port, TCPC_TX_SOP)) |
+			  VDO_OPOS(opos) | VDO_CMDT(CMDT_INIT) | CMD_EXIT_MODE);
+
+		if (!pd_setup_vdm_request(port, TCPC_TX_SOP, &vdm, 1)) {
+			dpm_clear_mode_exit_request(port);
+			return;
+		}
+
+		pe_dpm_request(port, DPM_REQUEST_VDM);
+	}
+}
diff --git a/common/usbc/usb_pe_drp_sm.c b/common/usbc/usb_pe_drp_sm.c
index 110ef413ed..beffd61d60 100644
--- a/common/usbc/usb_pe_drp_sm.c
+++ b/common/usbc/usb_pe_drp_sm.c
@@ -475,8 +475,6 @@ static struct policy_engine {
 	struct pd_discovery discovery[DISCOVERY_TYPE_COUNT];
 	/* Active alternate modes */
 	struct partner_active_modes partner_amodes[AMODE_TYPE_COUNT];
-	/* Alternate mode object position */
-	int8_t alt_opos;
 
 	/* Partner type to send */
 	enum tcpm_transmit_type tx_type;
@@ -1076,35 +1074,6 @@ void pd_send_vdm(int port, uint32_t vid, int cmd, const uint32_t *data,
 	task_wake(PD_PORT_TO_TASK_ID(port));
 }
 
-/* TODO: Add a common exit routine for all the alternate modes */
-void pe_exit_dp_mode(int port)
-{
-	if (IS_ENABLED(CONFIG_USB_PD_ALT_MODE_DFP)) {
-		int opos = pd_alt_mode(port, TCPC_TX_SOP, USB_SID_DISPLAYPORT);
-
-		if (opos <= 0)
-			return;
-
-		/*
-		 * TODO: Delay deleting the data until after the
-		 * the EXIT_MODE message is sent.
-		 * Unfortunately the callers of this function expect
-		 * the mode to be cleaned up before return.
-		 */
-		CPRINTS("C%d Exiting DP mode", port);
-		if (!pd_dfp_exit_mode(port, TCPC_TX_SOP, USB_SID_DISPLAYPORT,
-					opos))
-			return;
-
-		/*
-		 * Save the opos to be used with the message.
-		 * Request a message to be sent to exit the mode.
-		 */
-		pe[port].alt_opos = opos;
-		pe_dpm_request(port, DPM_REQUEST_EXIT_DP_MODE);
-	}
-}
-
 static void pe_handle_detach(void)
 {
 	const int port = TASK_ID_TO_PD_PORT(task_get_current());
@@ -1192,28 +1161,6 @@ static bool common_src_snk_dpm_requests(int port)
 						PD_T_DISCOVER_IDENTITY;
 		}
 		return true;
-	} else if (PE_CHK_DPM_REQUEST(port,
-				     DPM_REQUEST_EXIT_DP_MODE)) {
-		PE_CLR_DPM_REQUEST(port,
-					DPM_REQUEST_EXIT_DP_MODE);
-		/*
-		 * Init VDM CMD_EXIT_MODE message.
-		 * alt_opos must be set with the opos to be sent.
-		 * TODO: Convert this to use DPM_REQUEST_VDM.
-		 */
-		pe[port].tx_type = TCPC_TX_SOP;
-		pe[port].vdm_data[0] = VDO(
-					USB_SID_DISPLAYPORT,
-					1, /* structured */
-					VDO_SVDM_VERS(
-					    pd_get_vdo_ver(port, TCPC_TX_SOP)) |
-					VDO_OPOS(pe[port].alt_opos) |
-					VDO_CMDT(CMDT_INIT) |
-					CMD_EXIT_MODE);
-		pe[port].vdm_cnt = 1;
-		set_state_pe(port, PE_VDM_REQUEST_DPM);
-		return true;
-
 	} else if (PE_CHK_DPM_REQUEST(port, DPM_REQUEST_VDM)) {
 		PE_CLR_DPM_REQUEST(port, DPM_REQUEST_VDM);
 
@@ -2137,6 +2084,14 @@ static void pe_src_ready_run(int port)
 			return;
 		}
 
+		/*
+		 * TODO b/155890173: Combine the entry and exit mode requests
+		 * so that there is only a single entry point into DPM.
+		 */
+
+		/* No DPM requests; attempt mode exit if needed */
+		dpm_attempt_mode_exit(port);
+
 		/* No DPM requests; attempt mode entry if needed */
 		dpm_attempt_mode_entry(port);
 	}
@@ -2879,6 +2834,13 @@ static void pe_snk_ready_run(int port)
 			return;
 		}
 
+		/*
+		 * TODO b/155890173: Combine the entry and exit mode requests
+		 * so that there is only a single entry point into DPM.
+		 */
+		/* No DPM requests; attempt mode exit if needed */
+		dpm_attempt_mode_exit(port);
+
 		/* No DPM requests; attempt mode entry if needed */
 		dpm_attempt_mode_entry(port);
 	}
diff --git a/common/usbc/usb_tc_drp_acc_trysrc_sm.c b/common/usbc/usb_tc_drp_acc_trysrc_sm.c
index 5b068fb1f2..b2f137b93e 100644
--- a/common/usbc/usb_tc_drp_acc_trysrc_sm.c
+++ b/common/usbc/usb_tc_drp_acc_trysrc_sm.c
@@ -14,6 +14,7 @@
 #include "usb_common.h"
 #include "usb_mux.h"
 #include "usb_pd.h"
+#include "usb_pd_dpm.h"
 #include "usb_pe_sm.h"
 #include "usb_prl_sm.h"
 #include "usb_sm.h"
@@ -1432,7 +1433,7 @@ void tc_event_check(int port, int evt)
 			if (evt & PD_EVENT_SYSJUMP) {
 				for (i = 0; i <
 					CONFIG_USB_PD_PORT_MAX_COUNT; i++)
-					pe_exit_dp_mode(i);
+					dpm_set_mode_exit_request(i);
 				notify_sysjump_ready();
 			}
 		}
@@ -1553,10 +1554,10 @@ static void handle_new_power_state(int port)
 		if (chipset_in_or_transitioning_to_state(
 					CHIPSET_STATE_ANY_OFF)) {
 			/*
-			 * The SoC will negotiate DP mode again when it
+			 * The SoC will negotiate alternate mode again when it
 			 * boots up
 			 */
-			pe_exit_dp_mode(port);
+			dpm_set_mode_exit_request(port);
 
 			/*
 			 * The following function will disconnect both USB and