servo_v4: Support to enable Type C DTS mode

- Defined the config option CONFIG_USB_PD_DTS to board.h.
- Added ccd_set_mode function in board.c
- Removed ccd attach/detach functions from board.c as that function is
- now integrated in the the usb_pd state machine.
- Removed the fixed polarity that was being used in usb_pd_config.h so
  that the DUT port could connect as a SNK device.
- Defined PD_ROLE_DEFAULT to override the value in usb_Pd.h so that
  CHG is SNK and DUT is SRC

This set of changes allows servo_v4 to act like a suzyq. Hoever, PD
messaging is still not supported. The CHG port can still connect as a
SNK device, but VBUS on the DUT is only being provided by the host and
not the CHG port.

BUG=chrome-os-partner:61878
BRANCH=None
TEST=Manual Connected zinger to CHG port and verifed via servo_v4
console that it reached SNK_READY. Connected DUT port to Reef and
verified that it reached SRC_ACCESSORY state and that the correct SBU
polarity was selected and that lsusb shows H1 as a USB device.
Bus 003 Device 042: ID 18d1:5014 Google Inc.

Signed-off-by: Scott <scollyer@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/428309
Commit-Ready: Scott Collyer <scollyer@chromium.org>
Tested-by: Scott Collyer <scollyer@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Change-Id: I4a0ab2468f383a3ba4db3a3236bb18df6a2c405a
Reviewed-on: https://chromium-review.googlesource.com/506954
Reviewed-by: Nick Sanders <nsanders@chromium.org>

4 files changed, 122 insertions, 275 deletions

diff --git a/board/servo_v4/board.c b/board/servo_v4/board.c
index 9fb6fbd502..99a0fa1500 100644
--- a/board/servo_v4/board.c
+++ b/board/servo_v4/board.c
@@ -6,6 +6,7 @@
 
 #include "adc.h"
 #include "adc_chip.h"
+#include "case_closed_debug.h"
 #include "common.h"
 #include "console.h"
 #include "ec_version.h"
@@ -303,186 +304,63 @@ static void init_ioexpander(void)
 	i2c_write8(1, 0x40, 0x7, 0x0);
 }
 
-/* State of CC lines presented to DUT */
-/* Dual Rd pulldown, classic debug device. */
-#define CCD_ID_RDRD	0
-/* RpUSB + Rp1A5, indicates a self powered dongle. */
-#define CCD_ID_RPUSB	1
-/* One Rd. Device w/o CCD */
-#define CCD_ID_NONE	4
-
-static int ccd_id = CCD_ID_NONE;
-
-/* Set CC values according to requested mode. */
-static void init_ccd(int mode)
-{
-	int cc1_rd = GPIO_INPUT;
-	int cc2_rd = GPIO_INPUT;
-	int cc1_rpusb = GPIO_INPUT;
-	int cc2_rpusb = GPIO_INPUT;
-	int cc1_rp1a5 = GPIO_INPUT;
-	int cc2_rp1a5 = GPIO_INPUT;
-	int cc1_rp3a0 = GPIO_INPUT;
-	int cc2_rp3a0 = GPIO_INPUT;
-
-	switch (mode) {
-	case CCD_ID_RDRD:
-		cc1_rd = GPIO_OUT_LOW;
-		cc2_rd = GPIO_OUT_LOW;
-		break;
-
-	case CCD_ID_RPUSB:
-		cc1_rpusb = GPIO_OUT_HIGH;
-		cc2_rp1a5 = GPIO_OUT_HIGH;
-		break;
-
-	default:
-		cc1_rd = GPIO_OUT_LOW;
-		mode = CCD_ID_NONE;
-		break;
-	}
-
-	gpio_set_flags(GPIO_USB_DUT_CC1_RD, cc1_rd);
-	gpio_set_flags(GPIO_USB_DUT_CC2_RD, cc2_rd);
-	gpio_set_flags(GPIO_USB_DUT_CC1_RPUSB, cc1_rpusb);
-	gpio_set_flags(GPIO_USB_DUT_CC2_RPUSB, cc2_rpusb);
-	gpio_set_flags(GPIO_USB_DUT_CC1_RP1A5, cc1_rp1a5);
-	gpio_set_flags(GPIO_USB_DUT_CC2_RP1A5, cc2_rp1a5);
-	gpio_set_flags(GPIO_USB_DUT_CC1_RP3A0, cc1_rp3a0);
-	gpio_set_flags(GPIO_USB_DUT_CC2_RP3A0, cc2_rp3a0);
-
-	/* Disable CCD until we can detect orientation */
-	gpio_set_level(GPIO_SBU_MUX_EN, 0);
-	write_ioexpander(0, 0, 0);
-
-	ccd_id = mode;
-}
-
-
-/* Define voltage thresholds for CCD and SBU USB detection */
+/* Define voltage thresholds for SBU USB detection */
 #define GND_MAX_MV	350
-#define PULL_0V35_MV	350
-#define PULL_0V55_MV	550
-#define PULL_0V9_MV	900
-#define PULL_1V1_MV	1100
-#define PULL_2V0_MV	2000
-#define POWER_MIN_MV	3000
 #define USB_HIGH_MV	1500
+/* Tracks current state of ccd */
+static int ccd_mode;
 
-/* Check if presented CCD was accepted by the device */
-static int check_ccd_request(int cc1, int cc2)
-{
-	if ((ccd_id == CCD_ID_RDRD) &&
-	    (cc1 > PULL_0V35_MV) && (cc1 < PULL_0V55_MV) &&
-	    (cc2 > PULL_0V35_MV) && (cc2 < PULL_0V55_MV))
-		return 1;
-
-	if ((ccd_id == CCD_ID_RPUSB) &&
-	    (cc1 > PULL_0V35_MV) && (cc1 < PULL_0V55_MV) &&
-	    (cc2 > PULL_0V9_MV) && (cc2 < PULL_1V1_MV))
-		return 1;
-
-	return 0;
-}
+static void ccd_measure_sbu(void);
+DECLARE_DEFERRED(ccd_measure_sbu);
 
-/* Check if CC lines indicate an unplug event */
-static int check_usb_disconnect(int cc1, int cc2)
+static void ccd_measure_sbu(void)
 {
-	if ((cc1 < GND_MAX_MV) && (cc2 < GND_MAX_MV))
-		return 1;
-
-	if ((cc1 > POWER_MIN_MV) && (cc2 > POWER_MIN_MV))
-		return 1;
-
-	return 0;
+	int sbu1;
+	int sbu2;
+
+	/* Read sbu voltage levels */
+	sbu1 = adc_read_channel(ADC_SBU1_DET);
+	sbu2 = adc_read_channel(ADC_SBU2_DET);
+
+	/* USB FS pulls one line high for connect request */
+	if ((sbu1 > USB_HIGH_MV) && (sbu2 < GND_MAX_MV)) {
+		/* SBU flip = 1 */
+		write_ioexpander(0, 2, 1);
+		msleep(10);
+		gpio_set_level(GPIO_SBU_MUX_EN, 1);
+		ccd_mode = CCD_MODE_ENABLED;
+		CPRINTS("CCD: connected flip");
+	} else if ((sbu2 > USB_HIGH_MV) &&
+		   (sbu1 < GND_MAX_MV)) {
+		/* SBU flip = 0 */
+		write_ioexpander(0, 2, 0);
+		msleep(10);
+		gpio_set_level(GPIO_SBU_MUX_EN, 1);
+		ccd_mode = CCD_MODE_ENABLED;
+		CPRINTS("CCD: connected noflip");
+	} else {
+		/* Measure again after 100 msec */
+		hook_call_deferred(&ccd_measure_sbu_data, 100 * MSEC);
+	}
 }
 
-
-/* Current mode for CCD USB line connection */
-/* Cable not plugged in */
-#define CCD_MODE_DISCONNECTED	0
-/* Cable plugged in, CCD detected in default orientation */
-#define CCD_MODE_CONNECTED	1
-/* Cable plugged in, CCD detected in flip orientation */
-#define CCD_MODE_CONNECTED_FLIP	2
-/* Cable plugged in, nothing detected on SBU lines */
-#define CCD_MODE_CONNECTED_NONE	3
-/* No type-c cable in servo. */
-#define CCD_MODE_USBA		4
-
-static int mode = CCD_MODE_DISCONNECTED;
-
-/*
- * We don't have an available interrupt, so we'll just check this
- * every second. Update state every tick if necessary.
- */
-static void usb_sbu_tick(void)
+void ccd_set_mode(enum ccd_mode new_mode)
 {
-	int cc1, cc2;
-
-	/* Check if we have a CCD cable */
-	if ((mode == CCD_MODE_USBA) || !gpio_get_level(GPIO_DONGLE_DET)) {
-		mode = CCD_MODE_USBA;
-		return;
-	}
-
-	/* Check CC lines via ADC */
-	cc1 = adc_read_channel(ADC_DUT_CC1_PD);
-	cc2 = adc_read_channel(ADC_DUT_CC2_PD);
-
-	if (mode == CCD_MODE_DISCONNECTED) {
-		/* Check if both CC lines are pulled, and we are connected */
-		if (check_ccd_request(cc1, cc2)) {
-			int sbu1;
-			int sbu2;
-
-			/*
-			 * Give the onboard CCD micro 100ms
-			 * to notice and enable USB, then check adc levels.
-			 */
-			usleep(100000);
-			sbu1 = adc_read_channel(ADC_SBU1_DET);
-			sbu2 = adc_read_channel(ADC_SBU2_DET);
-
-			CPRINTS("CCD: Plug detect cc1:%d cc2:%d "
-				"sbu1:%d, sbu2:%d",
-				cc1, cc2, sbu1, sbu2);
-
-			/* USB FS pulls one line high for connect request */
-			if ((sbu1 > USB_HIGH_MV) && (sbu2 < GND_MAX_MV)) {
-				/* SBU flip = 1 */
-				write_ioexpander(0, 2, 1);
-				usleep(10000);
-				gpio_set_level(GPIO_SBU_MUX_EN, 1);
-				mode = CCD_MODE_CONNECTED;
-				CPRINTS("CCD: connected flip");
-			} else if ((sbu2 > USB_HIGH_MV) &&
-				   (sbu1 < GND_MAX_MV)) {
-				/* SBU flip = 0 */
-				write_ioexpander(0, 2, 0);
-				usleep(10000);
-				gpio_set_level(GPIO_SBU_MUX_EN, 1);
-				mode = CCD_MODE_CONNECTED_FLIP;
-				CPRINTS("CCD: connected noflip");
-			} else {
-				mode = CCD_MODE_CONNECTED_NONE;
-				CPRINTS("CCD: connected none");
-			}
-		}
-	} else {
-		/* mode == CCD_MODE_CONNECTED[_FLIP] */
-		if (check_usb_disconnect(cc1, cc2)) {
-			/* We are not connected to anything */
-
-			/* Turn off CCD */
-			gpio_set_level(GPIO_SBU_MUX_EN, 0);
-			CPRINTS("CCD: disconnect");
-			mode = CCD_MODE_DISCONNECTED;
-		}
+	if (new_mode == CCD_MODE_ENABLED) {
+		/* Allow some time following turning on of VBUS */
+		hook_call_deferred(&ccd_measure_sbu_data,
+				   PD_POWER_SUPPLY_TURN_ON_DELAY);
+	} else if (new_mode == CCD_MODE_DISABLED) {
+		/* We are not connected to anything */
+
+		/* Disable ccd_measure_sbu deferred call always */
+		hook_call_deferred(&ccd_measure_sbu_data, -1);
+		/* Turn off CCD */
+		gpio_set_level(GPIO_SBU_MUX_EN, 0);
+		CPRINTS("CCD: disconnect");
+		ccd_mode = CCD_MODE_DISABLED;
 	}
 }
-DECLARE_HOOK(HOOK_TICK, usb_sbu_tick, HOOK_PRIO_DEFAULT);
-
 
 static void board_init(void)
 {
@@ -507,38 +385,7 @@ static void board_init(void)
 	init_ioexpander();
 	init_uservo_port();
 
-	/*
-	 * TODO(crosbug.com/p/60828): The result of init_ccd() will be
-	 * overwritten when the usb pd protocol state machine attempts to attach
-	 * as SNK or SRC since it will modify the pullup/pulldown resistor on
-	 * the chosen polarity CC line.
-	 */
-	/* Enable CCD if type-c */
-	if (gpio_get_level(GPIO_DONGLE_DET))
-		init_ccd(CCD_ID_RPUSB);
+	/* Initialize CCD mode and disable sbu mux. */
+	ccd_set_mode(CCD_MODE_DISABLED);
 }
 DECLARE_HOOK(HOOK_INIT, board_init, HOOK_PRIO_DEFAULT);
-
-static int command_ccd(int argc, char **argv)
-{
-	int mode = CCD_ID_NONE;
-
-	if (argc < 2)
-		return EC_ERROR_PARAM_COUNT;
-
-	/* Handle requested mode */
-	if (!strcasecmp(argv[1], "rdrd"))
-		mode = CCD_ID_RDRD;
-	else if (!strcasecmp(argv[1], "rpusb"))
-		mode = CCD_ID_RPUSB;
-	else if (!strcasecmp(argv[1], "off"))
-		mode = CCD_ID_NONE;
-	else
-		return EC_ERROR_PARAM1;
-
-	init_ccd(mode);
-	ccprintf("DUT CC lines set to %s\n", argv[1]);
-	return EC_SUCCESS;
-}
-DECLARE_CONSOLE_COMMAND(ccd, command_ccd,
-	"[rdrd|rpusb|off]", "Set pullups or pulldowns to indicate CCD");
diff --git a/board/servo_v4/board.h b/board/servo_v4/board.h
index 94fc4bf69e..52bd17941f 100644
--- a/board/servo_v4/board.h
+++ b/board/servo_v4/board.h
@@ -78,12 +78,16 @@
 #undef CONFIG_TASK_PROFILING
 
 #define CONFIG_USB_POWER_DELIVERY
+#define CONFIG_USB_PD_DTS
 #define CONFIG_USB_PD_DUAL_ROLE
 #define CONFIG_USB_PD_INTERNAL_COMP
 #define CONFIG_USB_PD_PORT_COUNT 2
 #define CONFIG_USB_PD_TCPC
 #define CONFIG_USB_PD_TCPM_STUB
 
+/* Override PD_ROLE_DEFAULT in usb_pd.h */
+#define PD_ROLE_DEFAULT(port) ((port) ? PD_ROLE_SOURCE : PD_ROLE_SINK)
+
 /* 3.0A Standard-current Rp */
 #define PD_SRC_VNC           PD_SRC_DEF_VNC_MV
 #define PD_SRC_RD_THRESHOLD  PD_SRC_DEF_RD_THRESH_MV
diff --git a/board/servo_v4/usb_pd_config.h b/board/servo_v4/usb_pd_config.h
index 80e7bb7388..c9c21726e2 100644
--- a/board/servo_v4/usb_pd_config.h
+++ b/board/servo_v4/usb_pd_config.h
@@ -14,13 +14,6 @@
 #ifndef __CROS_EC_USB_PD_CONFIG_H
 #define __CROS_EC_USB_PD_CONFIG_H
 
-/*
- * For DUT PD port uses a fixed cable and both CC lines are connected. Need to
- * choose a default polarity. DUT_CC_POLARITY is this selection.
- */
-#define DUT_CC_POLARITY 0
-
-
 /* NOTES: Servo V4 and glados equivalents:
  *	Glados		Servo V4
  *	C0		CHG
@@ -226,49 +219,54 @@ static inline void pd_tx_init(void)
 
 static inline void pd_set_host_mode(int port, int enable)
 {
-	if (port == 0) {
-		/* CHG port. Rd is wired to 5k pulldown. */
-		/* Can't set host mode. */
+	/*
+	 * CHG (port == 0) port has fixed Rd attached and therefore can only
+	 * present as a SNK device. If port != DUT (port == 1), then nothing to
+	 * do in this function.
+	 */
+	if (!port)
+		return;
+
+	if (enable) {
+		/*
+		 * Servo_v4 in SRC mode acts as a DTS (debug test
+		 * accessory) and needs to present Rp on both CC
+		 * lines. In order to support orientation detection, the
+		 * values of Rp1/Rp2 need to asymmetric with Rp1 > Rp2.
+		 */
+
+		/* Set Rd for CC1/CC2 to High-Z. */
+		gpio_set_flags(GPIO_USB_DUT_CC1_RD, GPIO_INPUT);
+		gpio_set_flags(GPIO_USB_DUT_CC2_RD, GPIO_INPUT);
+
+		/*
+		 * TODO(crosbug.com/p/60794): Currently always advertising
+		 * 1.5A. If CHG port is attached then can advertise 3A
+		 * instead. Additionally, if CHG port is not attached and having
+		 * to use host provided vbus, can 1.5A be advertised?
+		 */
+		/* Pull up for host mode */
+		gpio_set_flags(GPIO_USB_DUT_CC1_RP1A5, GPIO_OUTPUT);
+		gpio_set_level(GPIO_USB_DUT_CC1_RP1A5, 1);
+		gpio_set_flags(GPIO_USB_DUT_CC2_RPUSB, GPIO_OUTPUT);
+		gpio_set_level(GPIO_USB_DUT_CC2_RPUSB, 1);
+		/* Set TX Hi-Z */
+		gpio_set_flags(GPIO_USB_DUT_CC1_TX_DATA, GPIO_INPUT);
+		gpio_set_flags(GPIO_USB_DUT_CC2_TX_DATA, GPIO_INPUT);
 	} else {
-		if (enable) {
-			/*
-			 * TODO(crosbug.com/p/60792): Similar to what's done for
-			 * SNK mode, only want to adjust the CC line that
-			 * matches the chosen polarity for the DUT port. Since
-			 * DUT port uses a fixed cable and both CC lines are
-			 * connected will only need to toggle 1 of the CC lines.
-			 */
-			/* High-Z is used for host mode. */
-			gpio_set_flags(GPIO_USB_DUT_CC1_RD, GPIO_INPUT);
-			gpio_set_flags(GPIO_USB_DUT_CC2_RD, GPIO_INPUT);
-			/* Pull up for host mode */
-			gpio_set_flags(GPIO_USB_DUT_CC1_RP1A5, GPIO_OUTPUT);
-			gpio_set_level(GPIO_USB_DUT_CC1_RP1A5, 1);
-			gpio_set_flags(GPIO_USB_DUT_CC2_RP1A5, GPIO_OUTPUT);
-			gpio_set_level(GPIO_USB_DUT_CC2_RP1A5, 1);
-			/* Set TX Hi-Z */
-			gpio_set_flags(GPIO_USB_DUT_CC1_TX_DATA, GPIO_INPUT);
-			gpio_set_flags(GPIO_USB_DUT_CC2_TX_DATA, GPIO_INPUT);
-		} else {
-			/* Set RD to High-Z for device mode. */
-			gpio_set_flags(GPIO_USB_DUT_CC1_RP1A5, GPIO_INPUT);
-			gpio_set_flags(GPIO_USB_DUT_CC2_RP1A5, GPIO_INPUT);
-			/*
-			 * TODO(crosbug.com/p/60828): Undo what was done in
-			 * init_ccd.
-			 */
-			gpio_set_flags(GPIO_USB_DUT_CC1_RPUSB, GPIO_INPUT);
-			gpio_set_flags(GPIO_USB_DUT_CC2_RPUSB, GPIO_INPUT);
-			if (DUT_CC_POLARITY == 0) {
-				gpio_set_flags(GPIO_USB_DUT_CC1_RD,
-					       GPIO_OUTPUT);
-				gpio_set_level(GPIO_USB_DUT_CC1_RD, 0);
-			} else {
-				gpio_set_flags(GPIO_USB_DUT_CC2_RD,
-					       GPIO_OUTPUT);
-				gpio_set_level(GPIO_USB_DUT_CC2_RD, 0);
-			}
-		}
+		/* Set Rp for CC1/CC2 to High-Z. */
+		gpio_set_flags(GPIO_USB_DUT_CC1_RP3A0, GPIO_INPUT);
+		gpio_set_flags(GPIO_USB_DUT_CC2_RP3A0, GPIO_INPUT);
+		gpio_set_flags(GPIO_USB_DUT_CC1_RP1A5, GPIO_INPUT);
+		gpio_set_flags(GPIO_USB_DUT_CC2_RP1A5, GPIO_INPUT);
+		gpio_set_flags(GPIO_USB_DUT_CC1_RPUSB, GPIO_INPUT);
+		gpio_set_flags(GPIO_USB_DUT_CC2_RPUSB, GPIO_INPUT);
+
+		/* DTS in SNK mode presents Rd on CC1/CC2 */
+		gpio_set_flags(GPIO_USB_DUT_CC1_RD, GPIO_OUTPUT);
+		gpio_set_flags(GPIO_USB_DUT_CC2_RD, GPIO_OUTPUT);
+		gpio_set_level(GPIO_USB_DUT_CC1_RD, 0);
+		gpio_set_level(GPIO_USB_DUT_CC2_RD, 0);
 	}
 }
 
@@ -301,21 +299,8 @@ static inline int pd_adc_read(int port, int cc)
 
 	if (port == 0)
 		mv = adc_read_channel(cc ? ADC_CHG_CC2_PD : ADC_CHG_CC1_PD);
-	else {
-		/*
-		 * TODO(crosbug.com/p/60792): Only want to read the CC line that
-		 * matches the chosen polarity for DUT port. If not for the
-		 * chosen polarity, then return 0. This only works when the DUT
-		 * port is presenting as a SNK device. Need to fix this so that
-		 * the returned value for the cc line that doesn't match the
-		 * chosen polarity returns 0 for SNK and 3300 for SRC mode.
-		 */
-		if (cc == DUT_CC_POLARITY)
-			mv = adc_read_channel(cc ? ADC_DUT_CC2_PD :
-						ADC_DUT_CC1_PD);
-		else
-			mv = 0;
-	}
+	else
+		mv = adc_read_channel(cc ? ADC_DUT_CC2_PD : ADC_DUT_CC1_PD);
 
 	return mv;
 }
diff --git a/board/servo_v4/usb_pd_policy.c b/board/servo_v4/usb_pd_policy.c
index e26562794b..48cce3519b 100644
--- a/board/servo_v4/usb_pd_policy.c
+++ b/board/servo_v4/usb_pd_policy.c
@@ -59,21 +59,32 @@ void pd_transition_voltage(int idx)
 
 int pd_set_power_supply_ready(int port)
 {
+	/* Port 0 can never provide vbus. */
+	if (!port)
+		return EC_ERROR_INVAL;
+
+	/*
+	 * TODO(crosbug.com/p/60794): For now always assume VBUS is supplied by
+	 * host. No support yet for using CHG VBUS passthru mode.
+	 */
+
 	/*
-	 * TODO(crosbug.com/p/60794): Will likely need to set the GPIOs
-	 * DUT_CHG_EN and HOST_OR_CHG_CTL which control whether DUT port
-	 * provides VBUS from Host or CHG port.
+	 * Select Host as source for VBUS.
+	 * To select host, set GPIO_HOST_OR_CHG_CTL low. To select CHG as VBUS
+	 * source, then set GPIO_HOST_OR_CHG_CTL high.
 	 */
+	gpio_set_level(GPIO_HOST_OR_CHG_CTL, 0);
+
+	/* Enable VBUS from the source selected above. */
+	gpio_set_level(GPIO_DUT_CHG_EN, 1);
+
 	return EC_SUCCESS; /* we are ready */
 }
 
 void pd_power_supply_reset(int port)
 {
-	/*
-	 * TODO(crosbug.com/p/60794): Will need to set the GPIOs
-	 * DUT_CHG_EN and HOST_OR_CHG_CTL which control whether DUT port
-	 * provides VBUS from Host or CHG port.
-	 */
+	/* Disable VBUS */
+	gpio_set_level(GPIO_DUT_CHG_EN, 0);
 }
 
 void pd_set_input_current_limit(int port, uint32_t max_ma,