pd: Add support for TCPC Alert and Alert_Mask registers

Changed the alert function to hold the ec_int line until
all of the alert bits are cleared. Added support for the
alert_mask register. In addition, created ec_int_status
variable to distinguish which of 3 ec_int sources is
driving the pd_mcu_int line.

BUG=none
BRANCH=tot
TEST=Tested Zinger to Glados and Zinger to Samus and verified
that it established a power contract in both cases. Did not
test Oak, but put exact same changes in board.c as in glados.

Change-Id: I372e75b8fd5d66a0c01db18b46100b86fd9ac064
Signed-off-by: Scott Collyer <scollyer@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/278256
Reviewed-by: Alec Berg <alecaberg@chromium.org>

1 files changed, 36 insertions, 12 deletions

diff --git a/board/glados_pd/board.c b/board/glados_pd/board.c
index 776e30a29b..42e8958538 100644
--- a/board/glados_pd/board.c
+++ b/board/glados_pd/board.c
@@ -21,17 +21,13 @@
 
 #define CPRINTS(format, args...) cprints(CC_USBCHARGE, format, ## args)
 
+static uint32_t ec_int_status;
+
 void pd_send_ec_int(void)
 {
-	gpio_set_level(GPIO_EC_INT, 0);
-
-	/*
-	 * Delay long enough to guarantee EC see's the change.
-	 * TODO: make sure this delay is sufficient.
-	 */
-	usleep(5);
+	/* If any of 3 sources are active, then drive the line low */
+	gpio_set_level(GPIO_EC_INT, !ec_int_status);
 
-	gpio_set_level(GPIO_EC_INT, 1);
 }
 
 void vbus0_evt(enum gpio_signal signal)
@@ -84,8 +80,27 @@ const struct i2c_port_t i2c_ports[] = {
 };
 const unsigned int i2c_ports_used = ARRAY_SIZE(i2c_ports);
 
-void tcpc_alert(void)
+void tcpc_alert(int port)
 {
+	/*
+	 * This function is called when the TCPC sets one of
+	 * bits in the Alert register and that bit's corresponding
+	 * location in the Alert_Mask register is set.
+	 */
+	atomic_or(&ec_int_status, port ?
+		  PD_STATUS_TCPC_ALERT_1 : PD_STATUS_TCPC_ALERT_0);
+	pd_send_ec_int();
+}
+
+void tcpc_alert_clear(int port)
+{
+	/*
+	 * The TCPM has acknowledged all Alert bits and the
+	 * Alert# line needs to be set inactive. Clear
+	 * the corresponding port's bit in the static variable.
+	 */
+	atomic_clear(&ec_int_status, port ?
+		  PD_STATUS_TCPC_ALERT_1 : PD_STATUS_TCPC_ALERT_0);
 	pd_send_ec_int();
 }
 
@@ -93,6 +108,8 @@ void tcpc_alert(void)
 /* Console commands */
 static int command_ec_int(int argc, char **argv)
 {
+	/* Indicate that ec_int gpio is active due to host command */
+	atomic_or(&ec_int_status, PD_STATUS_HOST_EVENT);
 	pd_send_ec_int();
 
 	return EC_SUCCESS;
@@ -107,12 +124,19 @@ static int ec_status_host_cmd(struct host_cmd_handler_args *args)
 	struct ec_response_pd_status *r = args->response;
 
 	/*
-	 * TODO: use state here to notify EC of host events, tcpc port
-	 * 0 alert and tcpc port 1 alert.
+	 * ec_int_status is used to store state for HOST_EVENT,
+	 * TCPC 0 Alert, and TCPC 1 Alert bits.
 	 */
-	r->status = 0;
+	r->status = ec_int_status;
 	args->response_size = sizeof(*r);
 
+	/*
+	 * If the source of the EC int line was HOST_EVENT, it has
+	 * been acknowledged so can always clear HOST_EVENT bit
+	 * from the ec_int_status variable
+	 */
+	atomic_clear(&ec_int_status, PD_STATUS_HOST_EVENT);
+
 	return EC_RES_SUCCESS;
 }
 DECLARE_HOST_COMMAND(EC_CMD_PD_EXCHANGE_STATUS, ec_status_host_cmd,