Plankton: Added support for normal dualrole operation

Added a 'drp' option to the console command usbc_action that is
used to toggle dualrole mode operation on and off. The default
Plankton operation is not affected as this control is initialized
to be disabled. When dualrole mode is enabled, then both CC lines
are used and monitored.

BRANCH=none
BUG=chrome-os-partner:50074
TEST=Manual
Tested Plankton connected to Samus. Verified that when dualrole mode
is enabled that it can connect as both SRC and SNK. Tested with Type C
cable initially connected and disconnected. In addition, verified that
power role swaps behave correctly, and that when disabled, default
Plankton operation is resumed.

Change-Id: I60adfa25844a01a50ba45d5d92e17a3318f3e0a0
Signed-off-by: Scott <scollyer@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/325545
Commit-Ready: Scott Collyer <scollyer@chromium.org>
Tested-by: Scott Collyer <scollyer@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

1 files changed, 75 insertions, 12 deletions

diff --git a/board/plankton/board.c b/board/plankton/board.c
index 2e5f64418a..d52f94bca5 100644
--- a/board/plankton/board.c
+++ b/board/plankton/board.c
@@ -40,6 +40,7 @@ static enum typec_cable cable;
 
 static int active_cc;
 static int host_mode;
+static int drp_enable;
 
 static int sn75dp130_dpcd_init(void);
 
@@ -127,6 +128,7 @@ enum usbc_action {
 	USBC_ACT_CABLE_POLARITY0,
 	USBC_ACT_CABLE_POLARITY1,
 	USBC_ACT_CCD_EN,
+	USBC_ACT_DRP_TOGGLE,
 
 	/* Number of USBC actions */
 	USBC_ACT_COUNT
@@ -147,18 +149,27 @@ static void set_active_cc(int cc)
 {
 	active_cc = cc;
 
+	/*
+	 * If DRP mode is enabled, then set both CC lines based
+	 * on the current value of host_mode. If DRP mode is
+	 * disabled then only set the active CC line.
+	 */
 	/* Pull-up on CC2 */
 	gpio_set_flags(GPIO_USBC_CC2_HOST,
-		       (cc && host_mode) ? GPIO_OUT_HIGH : GPIO_INPUT);
+		       ((cc || drp_enable) && host_mode) ?
+		       GPIO_OUT_HIGH : GPIO_INPUT);
 	/* Pull-down on CC2 */
 	gpio_set_flags(GPIO_USBC_CC2_DEVICE_ODL,
-		       (cc && !host_mode) ? GPIO_OUT_LOW : GPIO_INPUT);
+		       ((cc || drp_enable) && !host_mode) ?
+		       GPIO_OUT_LOW : GPIO_INPUT);
 	/* Pull-up on CC1 */
 	gpio_set_flags(GPIO_USBC_CC1_HOST,
-		       (!cc && host_mode) ? GPIO_OUT_HIGH : GPIO_INPUT);
+		       ((!cc || drp_enable) && host_mode) ?
+		       GPIO_OUT_HIGH : GPIO_INPUT);
 	/* Pull-down on CC1 */
 	gpio_set_flags(GPIO_USBC_CC1_DEVICE_ODL,
-		       (!cc && !host_mode) ? GPIO_OUT_LOW : GPIO_INPUT);
+		       ((!cc || drp_enable) && !host_mode) ?
+		       GPIO_OUT_LOW : GPIO_INPUT);
 }
 
 /**
@@ -235,6 +246,39 @@ static void fake_disconnect_start(void)
 }
 DECLARE_DEFERRED(fake_disconnect_start);
 
+/**
+ * Enable or disable dualrole mode operation. By default Plankton has
+ * dualrole mode disabled and attempts to connect in a sink role. Console
+ * commands/button presses can cause it to switch to source_only/sink_only
+ * modes.
+ */
+static void update_usbc_dual_role(int dual_role)
+{
+	if (dual_role == PD_DRP_TOGGLE_ON) {
+		drp_enable = 1;
+		/*
+		 * Cable detect is not needed when operating in dualrole mode
+		 * since both CC lines are used and SRC/SNK changes are dictated
+		 * by the USB PD protocol state machine.
+		 */
+		hook_call_deferred(detect_cc_cable, -1);
+		/* Need to make sure both CC lines are set for SNK or SRC. */
+		set_active_cc(host_mode);
+		/* Ensure that PD communication is enabled. */
+		pd_comm_enable(1);
+	} else {
+		drp_enable = 0;
+		/*
+		 * Dualrole mode is not active, resume cable detect function
+		 * which controls which CC line is active.
+		 */
+		hook_call_deferred(detect_cc_cable, 0);
+	}
+	/* Update dual role setting used in USB PD protocol state machine */
+	pd_set_dual_role(dual_role);
+	cprintf(CC_USBPD, "DRP = %d, host_mode = %d\n", drp_enable, host_mode);
+}
+
 static void set_usbc_action(enum usbc_action act)
 {
 	int need_soft_reset;
@@ -246,12 +290,12 @@ static void set_usbc_action(enum usbc_action act)
 	case USBC_ACT_20V_TO_DUT:
 		need_soft_reset = gpio_get_level(GPIO_VBUS_CHARGER_EN);
 		board_set_source_cap(src_cap_mapping[act]);
-		pd_set_dual_role(PD_DRP_FORCE_SOURCE);
+		update_usbc_dual_role(PD_DRP_FORCE_SOURCE);
 		if (need_soft_reset)
 			pd_soft_reset();
 		break;
 	case USBC_ACT_DEVICE:
-		pd_set_dual_role(PD_DRP_FORCE_SINK);
+		update_usbc_dual_role(PD_DRP_FORCE_SINK);
 		break;
 	case USBC_ACT_USBDP_TOGGLE:
 		was_usb_mode = gpio_get_level(GPIO_USBC_SS_USB_MODE);
@@ -314,6 +358,11 @@ static void set_usbc_action(enum usbc_action act)
 		gpio_set_level(GPIO_CASE_CLOSE_EN, 1);
 		gpio_set_level(GPIO_CASE_CLOSE_DFU_L, 1);
 		break;
+	case  USBC_ACT_DRP_TOGGLE:
+		/* Toggle dualrole mode setting. */
+		update_usbc_dual_role(drp_enable ?
+				      PD_DRP_TOGGLE_OFF : PD_DRP_TOGGLE_ON);
+		break;
 	default:
 		break;
 	}
@@ -520,6 +569,8 @@ static int cmd_usbc_action(int argc, char *argv[])
 		act = USBC_ACT_CABLE_POLARITY0;
 	else if (!strcasecmp(argv[1], "pol1"))
 		act = USBC_ACT_CABLE_POLARITY1;
+	else if (!strcasecmp(argv[1], "drp"))
+		act = USBC_ACT_DRP_TOGGLE;
 	else
 		return EC_ERROR_PARAM1;
 
@@ -528,7 +579,7 @@ static int cmd_usbc_action(int argc, char *argv[])
 	return EC_SUCCESS;
 }
 DECLARE_CONSOLE_COMMAND(usbc_action, cmd_usbc_action,
-			"<5v|12v|20v|ccd|dev|usb|dp|flip|pol0|pol1>",
+			"<5v|12v|20v|ccd|dev|usb|dp|flip|pol0|pol1|drp>",
 			"Set Plankton type-C port state",
 			NULL);
 
@@ -590,12 +641,20 @@ int board_fake_pd_adc_read(int cc)
 		/* Always disconnected */
 		return fake_pd_host_mode ? 3000 : 0;
 	} else {
-		/* Only read the active CC line, fake disconnected on other */
-		if (active_cc == cc)
+		if (drp_enable) {
+			/* Always read the req CC line when in drp mode */
 			return adc_read_channel(cc ? ADC_CH_CC2_PD :
 						     ADC_CH_CC1_PD);
-		else
-			return host_mode ? 3000 : 0;
+		} else {
+			/*
+			 * Only read the active CC line, fake disconnected
+			 * on other CC line. */
+			if (active_cc == cc)
+				return adc_read_channel(cc ? ADC_CH_CC2_PD :
+							ADC_CH_CC1_PD);
+			else
+				return host_mode ? 3000 : 0;
+		}
 	}
 }
 
@@ -607,7 +666,8 @@ static void board_update_fake_adc_value(int host_mode)
 
 void board_pd_set_host_mode(int enable)
 {
-	cprintf(CC_USBPD, "Host mode: %d\n", enable);
+	if (!drp_enable)
+		cprintf(CC_USBPD, "Host mode: %d\n", enable);
 
 	if (board_pd_fake_disconnected()) {
 		board_update_fake_adc_value(enable);
@@ -647,6 +707,9 @@ static void board_init(void)
 	hpd_prev_ts = now.val;
 	gpio_enable_interrupt(GPIO_DPSRC_HPD);
 
+	/* Start up with dualrole mode off */
+	drp_enable = 0;
+
 	/* Enable interrupts on VBUS transitions. */
 	gpio_enable_interrupt(GPIO_VBUS_WAKE);