bloonchipper: Add transport and sensor detection

bloonchipper (aka hatch_fp aka dragonclaw) has a voltage divider that
can be used to select the sensor and the transport type.

Supported designs:
* Dragonclaw rev 0.2 (green with Google logo):
  go/dragonclaw-schematic-rev-0.2
* Hatch reference v3.0:
  go/hatch-schematic-rev-3.0

The selection lines are connected to ADC inputs, so a future change will
use the ADC to allow more than two transports or sensors.

BRANCH=none
BUG=b:147113851
TEST=flash dragonclaw rev 0.2 and view console output

Change-Id: If2e4b150d34cfe41477be528c70e1645043d4d82
Signed-off-by: Tom Hughes <tomhughes@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1986322
Reviewed-by: Craig Hesling <hesling@chromium.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/include/fpsensor_detect.h b/include/fpsensor_detect.h
new file mode 100644
index 0000000000..e12ff76595
--- /dev/null
+++ b/include/fpsensor_detect.h
@@ -0,0 +1,28 @@
+/* Copyright 2020 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Fingerprint sensor detection (transport and sensor). */
+
+#ifndef __CROS_EC_FPSENSOR_DETECT_H
+#define __CROS_EC_FPSENSOR_DETECT_H
+
+enum fp_sensor_type {
+	FP_SENSOR_TYPE_UNKNOWN = -1,
+	FP_SENSOR_TYPE_FPC,
+	FP_SENSOR_TYPE_ELAN,
+};
+
+enum fp_transport_type {
+	FP_TRANSPORT_TYPE_UNKNOWN = -1,
+	FP_TRANSPORT_TYPE_SPI,
+	FP_TRANSPORT_TYPE_UART
+};
+
+const char *fp_transport_type_to_str(enum fp_transport_type type);
+const char *fp_sensor_type_to_str(enum fp_sensor_type type);
+enum fp_sensor_type get_fp_sensor_type(void);
+enum fp_transport_type get_fp_transport_type(void);
+
+#endif /* __CROS_EC_FPSENSOR_DETECT_H */