Volteer: add monitoring for PROCHOT input

Add monotoring of the PROCHOT input to the EC.

BUG=b:152340521
BRANCH=none
TEST=makebuild all
TEST=Assert PROCHOT output from the EC and confirm EC console logging or
PROCHOT input.

Signed-off-by: Keith Short <keithshort@chromium.org>
Change-Id: Ib28537a227ea40ac947f7b999a85354b1ae4c111
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2120067
Reviewed-by: Abe Levkoy <alevkoy@chromium.org>
Commit-Queue: Abe Levkoy <alevkoy@chromium.org>

1 files changed, 50 insertions, 0 deletions

diff --git a/common/throttle_ap.c b/common/throttle_ap.c
index 8ecc71c207..52b9c96127 100644
--- a/common/throttle_ap.c
+++ b/common/throttle_ap.c
@@ -8,19 +8,25 @@
 #include "chipset.h"
 #include "common.h"
 #include "console.h"
+#include "hooks.h"
 #include "host_command.h"
 #include "task.h"
 #include "throttle_ap.h"
+#include "timer.h"
 #include "util.h"
 
 /* Console output macros */
 #define CPUTS(outstr) cputs(CC_THERMAL, outstr)
 #define CPRINTS(format, args...) cprints(CC_THERMAL, format, ## args)
 
+#define PROCHOT_IN_DEBOUNCE_US		(100 * MSEC)
+
 /*****************************************************************************/
 /* This enforces the virtual OR of all throttling sources. */
 static struct mutex throttle_mutex;
 static uint32_t throttle_request[NUM_THROTTLE_TYPES];
+static int debounced_prochot_in;
+static enum gpio_signal gpio_prochot_in = GPIO_COUNT;
 
 void throttle_ap(enum throttle_level level,
 		 enum throttle_type type,
@@ -70,6 +76,50 @@ void throttle_ap(enum throttle_level level,
 
 }
 
+static void prochot_input_deferred(void)
+{
+	int prochot_in;
+
+	/*
+	 * Shouldn't be possible, but better to protect against buffer
+	 * overflow
+	 */
+	ASSERT(signal_is_gpio(gpio_prochot_in));
+
+	prochot_in = gpio_get_level(gpio_prochot_in);
+
+	if (IS_ENABLED(CONFIG_CPU_PROCHOT_ACTIVE_LOW))
+		prochot_in = !prochot_in;
+
+	if (prochot_in == debounced_prochot_in)
+		return;
+
+	debounced_prochot_in = prochot_in;
+
+	if (debounced_prochot_in)
+		CPRINTS("External PROCHOT assertion detected");
+	else
+		CPRINTS("External PROCHOT condition cleared");
+}
+DECLARE_DEFERRED(prochot_input_deferred);
+
+void throttle_ap_prochot_input_interrupt(enum gpio_signal signal)
+{
+	/*
+	 * Save the PROCHOT signal that generated the interrupt so we don't
+	 * rely on a specific pin name.
+	 */
+	if (gpio_prochot_in == GPIO_COUNT)
+		gpio_prochot_in = signal;
+
+	/*
+	 * Trigger deferred notification of PROCHOT change so we can ignore
+	 * any pulses that are too short.
+	 */
+	hook_call_deferred(&prochot_input_deferred_data,
+		PROCHOT_IN_DEBOUNCE_US);
+}
+
 /*****************************************************************************/
 /* Console commands */
 #ifdef CONFIG_CMD_APTHROTTLE