kukui: Enable DP.

On plug DP dongle, we sohuld:
 1. set USB_C0_DP_POLARITY bit accordingly
 2. set USB_C0_DP_OE_L low
 3. set USB_C0_HPD_OD high

On unplug DP dongle, we should:
  1. set USB_C0_DP_OE_L high
  2. set USB_C0_HPD_OD low

TEST=pd 0 dualrole on; plug DP dongle, see GPIO pins set accordingly.
TEST=unplug DP dongle, see GPIO pins set accordingly.
TEST=plug dp and seeing output to external display for both polarity.
BUG=b:114162810
BRANCH=None

Change-Id: I4e4755e3b757d25a081fd65f8eb68235766d6e0b
Signed-off-by: Yilun Lin <yllin@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1221406
Commit-Ready: Yilun Lin <yllin@chromium.org>
Tested-by: Yilun Lin <yllin@chromium.org>
Reviewed-by: Yilun Lin <yllin@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>

2 files changed, 58 insertions, 11 deletions

diff --git a/board/kukui/gpio.inc b/board/kukui/gpio.inc
index b67489fb60..720eaa42c5 100644
--- a/board/kukui/gpio.inc
+++ b/board/kukui/gpio.inc
@@ -99,7 +99,7 @@ GPIO(EC_INT_L,             PIN(B, 12), GPIO_ODR_HIGH) /* EC_AP_INT_ODL */
 GPIO(EC_BOARD_ID_EN_L,     PIN(C, 15), GPIO_ODR_HIGH) /* EC_BOARD_ID_EN_ODL */
 GPIO(USB_C0_DISCHARGE,     PIN(B, 0),  GPIO_OUT_LOW)
 GPIO(USB_C0_DP_POLARITY,   PIN(C, 14), GPIO_OUT_LOW)
-GPIO(USB_C0_HPD_OD,        PIN(F, 1),  GPIO_ODR_HIGH)
+GPIO(USB_C0_HPD_OD,        PIN(F, 1),  GPIO_ODR_LOW)
 GPIO(BOOTBLOCK_MUX_OE,     PIN(C, 4),  GPIO_ODR_HIGH)
 GPIO(BOOTBLOCK_EN_L,       PIN(C, 1),  GPIO_ODR_HIGH)
 #if BOARD_REV == 0
diff --git a/board/kukui/usb_pd_policy.c b/board/kukui/usb_pd_policy.c
index c3bfa25760..42b0ce7e03 100644
--- a/board/kukui/usb_pd_policy.c
+++ b/board/kukui/usb_pd_policy.c
@@ -273,37 +273,84 @@ static int svdm_dp_config(int port, uint32_t *payload)
 	return 2;
 };
 
+/*
+ * timestamp of the next possible toggle to ensure the 2-ms spacing
+ * between IRQ_HPD.
+ */
+static uint64_t hpd_deadline[CONFIG_USB_PD_PORT_COUNT];
+
 static void svdm_dp_post_config(int port)
 {
+	const struct usb_mux * const mux = &usb_muxes[port];
+
 	dp_flags[port] |= DP_FLAGS_DP_ON;
+	if (!(dp_flags[port] & DP_FLAGS_HPD_HI_PENDING))
+		return;
+
+	gpio_set_level(GPIO_USB_C0_HPD_OD, 1);
+	gpio_set_level(GPIO_USB_C0_DP_OE_L, 0);
+	gpio_set_level(GPIO_USB_C0_DP_POLARITY, pd_get_polarity(port));
+
+	/* set the minimum time delay (2ms) for the next HPD IRQ */
+	hpd_deadline[port] = get_time().val + HPD_USTREAM_DEBOUNCE_LVL;
+	mux->hpd_update(port, 1, 0);
 }
 
 static int svdm_dp_attention(int port, uint32_t *payload)
 {
-	const struct usb_mux *mux = &usb_muxes[port];
+	int cur_lvl = gpio_get_level(GPIO_USB_C0_HPD_OD);
 	int lvl = PD_VDO_DPSTS_HPD_LVL(payload[1]);
 	int irq = PD_VDO_DPSTS_HPD_IRQ(payload[1]);
-	int mf_pref = PD_VDO_DPSTS_MF_PREF(payload[1]);
+	const struct usb_mux * const mux = &usb_muxes[port];
 
 	dp_status[port] = payload[1];
 
-	mux->hpd_update(port, lvl, irq);
+	/* Its initial DP status message prior to config */
+	if (!(dp_flags[port] & DP_FLAGS_DP_ON)) {
+		if (lvl)
+			dp_flags[port] |= DP_FLAGS_HPD_HI_PENDING;
+		return 1;
+	}
 
-	if (lvl)
-		usb_mux_set(port, mf_pref ? TYPEC_MUX_DOCK : TYPEC_MUX_DP,
-			    USB_SWITCH_CONNECT, pd_get_polarity(port));
-	else
-		usb_mux_set(port, mf_pref ? TYPEC_MUX_USB : TYPEC_MUX_NONE,
-			    USB_SWITCH_CONNECT, pd_get_polarity(port));
+	if (irq & cur_lvl) {
+		uint64_t now = get_time().val;
+		/* wait for the minimum spacing between IRQ_HPD if needed */
+		if (now < hpd_deadline[port])
+			usleep(hpd_deadline[port] - now);
+
+		/* generate IRQ_HPD pulse */
+		gpio_set_level(GPIO_USB_C0_HPD_OD, 0);
+		usleep(HPD_DSTREAM_DEBOUNCE_IRQ);
+		gpio_set_level(GPIO_USB_C0_HPD_OD, 1);
+
+		gpio_set_level(GPIO_USB_C0_DP_OE_L, 0);
+		gpio_set_level(GPIO_USB_C0_DP_POLARITY, pd_get_polarity(port));
+
+		/* set the minimum time delay (2ms) for the next HPD IRQ */
+		hpd_deadline[port] = get_time().val + HPD_USTREAM_DEBOUNCE_LVL;
+	} else if (irq & !cur_lvl) {
+		CPRINTF("ERR:HPD:IRQ&LOW\n");
+		return 0; /* nak */
+	} else {
+		gpio_set_level(GPIO_USB_C0_HPD_OD, lvl);
+		gpio_set_level(GPIO_USB_C0_DP_OE_L, !lvl);
+		gpio_set_level(GPIO_USB_C0_DP_POLARITY, pd_get_polarity(port));
+		/* set the minimum time delay (2ms) for the next HPD IRQ */
+		hpd_deadline[port] = get_time().val + HPD_USTREAM_DEBOUNCE_LVL;
+	}
 
+	mux->hpd_update(port, lvl, irq);
+	/* ack */
 	return 1;
 }
 
 static void svdm_exit_dp_mode(int port)
 {
-	const struct usb_mux *mux = &usb_muxes[port];
+	const struct usb_mux * const mux = &usb_muxes[port];
 
 	svdm_safe_dp_mode(port);
+	gpio_set_level(GPIO_USB_C0_HPD_OD, 0);
+	gpio_set_level(GPIO_USB_C0_DP_OE_L, 1);
 	mux->hpd_update(port, 0, 0);
 }