zephyr: Create devicetree node for keyscan

Create devicetree node to specify the keyscan runtime parameters.

BUG=b:195945894
BRANCH=none
TEST=zmake testall
TEST=verify keyboard on Volteer with next CL

Signed-off-by: Keith Short <keithshort@chromium.org>
Change-Id: I4dbf5e4f2205f31651d33b6ffc1ecd1dd6696795
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3083721
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>

3 files changed, 117 insertions, 0 deletions

diff --git a/zephyr/dts/bindings/keyboard/cros-keyscan.yaml b/zephyr/dts/bindings/keyboard/cros-keyscan.yaml
new file mode 100644
index 0000000000..11caf7fd11
--- /dev/null
+++ b/zephyr/dts/bindings/keyboard/cros-keyscan.yaml
@@ -0,0 +1,82 @@
+ # Copyright 2021 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.
+
+description: Keyboard scanning properties
+
+compatible: "cros-keyscan"
+
+properties:
+    output-settle:
+      type: int
+      required: false
+      default: 80
+      description: |
+          Delay time, in microseconds, between setting up output and waiting for
+          it to settle. 80 microseconds is the recommended value when column 2
+          of the keyboard passes through the Google Security Chip. Otherwise 50
+          microseconds is the recommended value.
+
+    debounce-down:
+      type: int
+      required: false
+      default: 9000
+      description: |
+          Time, in microseconds, to debounce key-down.
+
+    debounce-up:
+      type: int
+      required: false
+      default: 30000
+      description: |
+          Time, in microseconds, to debounce key-up.
+
+    scan-period:
+      type: int
+      required: false
+      default: 3000
+      description: |
+          Time between scans when keyboard scan task runs in polling mode.
+
+    min-post-scan-delay:
+      type: int
+      required: false
+      default: 1000
+      description: |
+          Minimum time between end of one scan and start of the next one.
+          This ensures keyboard scanning doesn't starve the rest of the system
+          if the scan period is set too short, or if other higher-priority
+          system activity is starving the keyboard scan task too.
+
+    poll-timeout:
+      type: int
+      required: false
+      default: 100000
+      description: |
+          Revert to interrupt mode after no keyboard activity for this period.
+          Specified in microseconds.
+
+    actual-key-mask:
+      type: array
+      required: false
+      default: [
+        0x1c, # C0
+        0xff, # C1
+        0xff, # C2
+        0xff, # C3
+        0xff, # C4
+        0xf5, # C5
+        0xff, # C6
+        0xa4, # C7
+        0xfe, # C8
+        0x55, # C9
+        0xfa, # C10
+        0xff, # C11
+        0xca, # C12
+        0x00, # C13 for keypad
+        0x00, # C14 for keypad
+      ]
+      description: |
+          Keyboard scanning mask. For each keyboard column, specify which
+          keyboard rows actually exist. Default key mask includes scanning for
+          full Chromebook keyboard, excluding the keypad.
diff --git a/zephyr/shim/src/CMakeLists.txt b/zephyr/shim/src/CMakeLists.txt
index 9b198ec3f2..7be2e75fb2 100644
--- a/zephyr/shim/src/CMakeLists.txt
+++ b/zephyr/shim/src/CMakeLists.txt
@@ -26,6 +26,7 @@ zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_HOSTCMD     host_command.c)
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_HOSTCMD_CONSOLE
                                                             console_buffer.c)
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_KEYBOARD    keyboard_raw.c)
+zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_KEYBOARD    keyscan.c)
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_MKBP_EVENT  mkbp_event.c)
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_MOTIONSENSE
                                                             motionsense_sensors.c)
diff --git a/zephyr/shim/src/keyscan.c b/zephyr/shim/src/keyscan.c
new file mode 100644
index 0000000000..514d9ffaed
--- /dev/null
+++ b/zephyr/shim/src/keyscan.c
@@ -0,0 +1,34 @@
+/* Copyright 2021 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.
+ */
+
+#define DT_DRV_COMPAT cros_kb_raw_keyscan
+
+#include <assert.h>
+#include <kernel.h>
+#include <soc.h>
+
+#include "keyboard_scan.h"
+
+#if DT_NODE_EXISTS(DT_INST(0, cros_kb_raw_keyscan))
+
+/* The keyboard matrix should have at least enough columns for the
+ * standard keyboard with no keypad.
+ */
+BUILD_ASSERT(DT_INST_PROP_LEN(0, actual_key_mask) >= KEYBOARD_COLS_NO_KEYPAD);
+
+/*
+ * Override the default keyscan_config if the board defines a
+ * cros-kb-raw-keyscan node.
+ */
+__override struct keyboard_scan_config keyscan_config = {
+	.output_settle_us = DT_INST_PROP(0, output_settle),
+	.debounce_down_us = DT_INST_PROP(0, debounce_down),
+	.debounce_up_us = DT_INST_PROP(0, debounce_up),
+	.scan_period_us = DT_INST_PROP(0, scan_period),
+	.min_post_scan_delay_us = DT_INST_PROP(0, min_post_scan_delay),
+	.poll_timeout_us = DT_INST_PROP(0, poll_timeout),
+	.actual_key_mask = DT_INST_PROP(0, actual_key_mask),
+};
+#endif