pd: Add support for multiple distinct TCPC alert signals

If multiple TCPCs are present on a system then we may have multiple
alert signals, each of which alerts us to the status of a different
TCPC. Make boards with external non cros-ec TCPCs define
tcpc_get_alert_status, which returns alert status based upon any alert
GPIOs present, and then service only ports which are alerting.

BUG=chromium:551683,chrome-os-partner:47851
TEST=Verify snoball PDCMD task sleeps appropriately when no devices are
inserted, and verify ports go to PD_DISCOVERY state when we attach
samus. Also verify that glados / glados_pd can still negotiate PD.
BRANCH=None

Change-Id: Iae6c4e1ef4d6685cb5bf7feef713505925a07c8c
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/313209
Commit-Ready: Shawn N <shawnn@chromium.org>
Tested-by: Shawn N <shawnn@chromium.org>
Reviewed-by: Alec Berg <alecaberg@chromium.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/board/pdeval-stm32f072/board.c b/board/pdeval-stm32f072/board.c
index 6fd472eee5..ab476d006e 100644
--- a/board/pdeval-stm32f072/board.c
+++ b/board/pdeval-stm32f072/board.c
@@ -61,3 +61,17 @@ const struct tcpc_config_t tcpc_config[CONFIG_USB_PD_PORT_COUNT] = {
 	{I2C_PORT_TCPC, TCPC2_I2C_ADDR},
 #endif
 };
+
+uint16_t tcpc_get_alert_status(void)
+{
+	uint16_t status = 0;
+
+	if (!gpio_get_level(GPIO_PD_MCU_INT)) {
+		status = PD_STATUS_TCPC_ALERT_0;
+#if CONFIG_USB_PD_PORT_COUNT >= 2
+		status |= PD_STATUS_TCPC_ALERT_1;
+#endif
+	}
+
+	return status;
+}