[HACK] pd: twinkie: allow sending SOP' Discover Identity

Add a console command (e.g. 'pd 0 vdm ident') to send a Discover
Identity with SOP' to read a cable e-marker information when we are in
sink mode.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=none
BUG=none
TEST=plug a Twinkie to one end of a full-featured type-C cable (with
e-Marker) and Samus to the other end (to get VCONN)

Go into 'Sink' on Twinkie
> tw sink
[11.922071 Jumping to image RW]

Pretend that we have a cable rather than a receptacle with 2 CC
connected
> tw resistor rd 0

We are seeing VBUS and VCONN
> tw cc
CC1 = 421 mV ; CC2 = 2491 mV
> tw vbus
VBUS = 5056 mV ; 0 mA

Send the Discover Identity VDM
> pd 0 vdm ident

Dump the values returned
> pe 0 dump
IDENT:
        [ID Header] 1c00050d :: PCable, VID:050d
        [Cert Stat] 00000000
        [2] 030a0000    [3] 11082032
SVID[0]: 04b4 MODES: [1] 00000001

Change-Id: I08a48af9062821518109db557589b7155f228a37
Reviewed-on: https://chromium-review.googlesource.com/684302
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Trybot-Ready: Vincent Palatin <vpalatin@chromium.org>
Commit-Queue: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

4 files changed, 25 insertions, 2 deletions

diff --git a/board/twinkie/board.h b/board/twinkie/board.h
index 2de4f1843f..05d11e2724 100644
--- a/board/twinkie/board.h
+++ b/board/twinkie/board.h
@@ -24,6 +24,8 @@
 #define CONFIG_WEBUSB_URL "storage.googleapis.com/webtwinkie.org/tool.html"
 
 #define CONFIG_USB_POWER_DELIVERY
+#define CONFIG_USB_PD_ALT_MODE
+#define CONFIG_USB_PD_ALT_MODE_DFP
 #define CONFIG_USB_PD_DUAL_ROLE
 #define CONFIG_USB_PD_INTERNAL_COMP
 #define CONFIG_USB_PD_PORT_COUNT 1
@@ -43,6 +45,7 @@
 #define CONFIG_ADC
 #define CONFIG_BOARD_PRE_INIT
 #define CONFIG_CMD_REBOOT_DFU
+#define CONFIG_CMD_USB_PD_PE
 #define CONFIG_I2C
 #define CONFIG_I2C_MASTER
 #define CONFIG_INA231
diff --git a/board/twinkie/usb_pd_policy.c b/board/twinkie/usb_pd_policy.c
index 8c70f438df..1a55456f20 100644
--- a/board/twinkie/usb_pd_policy.c
+++ b/board/twinkie/usb_pd_policy.c
@@ -99,8 +99,19 @@ void pd_execute_data_swap(int port, int data_role)
 	/* Do nothing */
 }
 
+/* ----------------- Vendor Defined Messages ------------------ */
+const struct svdm_response svdm_rsp = {
+	.identity = NULL,
+	.svids = NULL,
+	.modes = NULL,
+};
+
 int pd_custom_vdm(int port, int cnt, uint32_t *payload,
 		  uint32_t **rpayload)
 {
 	return 0;
 }
+
+const struct svdm_amode_fx supported_modes[] = {
+};
+const int supported_modes_cnt = ARRAY_SIZE(supported_modes);
diff --git a/common/usb_pd_protocol.c b/common/usb_pd_protocol.c
index ee4ae31ab0..426414deca 100644
--- a/common/usb_pd_protocol.c
+++ b/common/usb_pd_protocol.c
@@ -152,6 +152,7 @@ static struct pd_protocol {
 	/* next Vendor Defined Message to send */
 	uint32_t vdo_data[VDO_MAX_SIZE];
 	uint8_t vdo_count;
+	uint8_t vdm_tx_type;
 	/* VDO to retry if UFP responder replied busy. */
 	uint32_t vdo_retry;
 
@@ -1269,8 +1270,9 @@ static void pd_vdm_send_state_machine(int port)
 		header = PD_HEADER(PD_DATA_VENDOR_DEF, pd[port].power_role,
 				   pd[port].data_role, pd[port].msg_id,
 				   (int)pd[port].vdo_count);
-		res = pd_transmit(port, TCPC_TX_SOP, header,
+		res = pd_transmit(port, pd[port].vdm_tx_type, header,
 				  pd[port].vdo_data);
+		pd[port].vdm_tx_type = TCPC_TX_SOP;
 		if (res < 0) {
 			pd[port].vdm_state = VDM_STATE_ERR_SEND;
 		} else {
@@ -3478,6 +3480,10 @@ static int command_pd(int argc, char **argv)
 		} else if (!strncasecmp(argv[3], "vers", 4)) {
 			pd_send_vdm(port, USB_VID_GOOGLE, VDO_CMD_VERSION,
 				    NULL, 0);
+		} else if (!strncasecmp(argv[3], "ident", 4)) {
+			pd[port].vdm_tx_type = TCPC_TX_SOP_PRIME;
+			pd_send_vdm(port, USB_SID_PD, CMD_DISCOVER_IDENT,
+				    NULL, 0);
 		} else {
 			return EC_ERROR_PARAM_COUNT;
 		}
diff --git a/common/usb_pd_tcpc.c b/common/usb_pd_tcpc.c
index c3222cb57a..4846e33c2a 100644
--- a/common/usb_pd_tcpc.c
+++ b/common/usb_pd_tcpc.c
@@ -754,7 +754,10 @@ static int cc_voltage_to_status(int port, int cc_volt, int cc_sel)
 	}
 #ifdef CONFIG_USB_PD_DUAL_ROLE
 	else if (pd[port].cc_pull == TYPEC_CC_RD) {
-		if (cc_volt >= TYPE_C_SRC_3000_THRESHOLD)
+		if (cc_volt >= 3*TYPE_C_SRC_3000_THRESHOLD/2)
+			/* HACK for Twinkie: that's VCONN, ignore it */
+			return TYPEC_CC_VOLT_OPEN;
+		else if (cc_volt >= TYPE_C_SRC_3000_THRESHOLD)
 			return TYPEC_CC_VOLT_SNK_3_0;
 		else if (cc_volt >= TYPE_C_SRC_1500_THRESHOLD)
 			return TYPEC_CC_VOLT_SNK_1_5;