feat(pointing): Release pressed keys on disconnect (#3204)

Match the behavior for key press release on split peripheral disconnect,
and track pressed input keys to release them as needed on disconnect.

app/include/zmk/pointing/input_split.h

@@ -7,4 +7,5 @@
 #pragma once
 
 int zmk_input_split_report_peripheral_event(uint8_t reg, uint8_t type, uint16_t code, int32_t value,
-                                            bool sync);
+                                            bool sync);
+int zmk_input_split_peripheral_disconnected(uint8_t reg);

app/src/pointing/Kconfig

@@ -78,6 +78,11 @@ config ZMK_INPUT_SPLIT_INIT_PRIORITY
     int "Input Split initialization priority"
     default INPUT_INIT_PRIORITY
 
+
+config ZMK_INPUT_SPLIT_MAX_TRACKED_KEYS
+    int "Input Split max tracked keys to release on peripheral disconnect"
+    default 5
+
 endif # ZMK_INPUT_SPLIT
 
 endif # ZMK_POINTING

app/src/pointing/input_split.c

@@ -26,11 +26,42 @@ struct zis_entry {
 
 static const struct zis_entry proxy_inputs[] = {DT_INST_FOREACH_STATUS_OKAY(ZIS_ENTRY)};
 
+static uint16_t proxy_active_keys[DT_NUM_INST_STATUS_OKAY(DT_DRV_COMPAT)]
+                                 [CONFIG_ZMK_INPUT_SPLIT_MAX_TRACKED_KEYS];
+
+static int replace_active_key(size_t input, uint16_t find, uint16_t replace) {
+    for (size_t k = 0; k < CONFIG_ZMK_INPUT_SPLIT_MAX_TRACKED_KEYS; k++) {
+        if (proxy_active_keys[input][k] == find) {
+            proxy_active_keys[input][k] = replace;
+            return 0;
+        }
+    }
+
+    return -ENODEV;
+}
+
 int zmk_input_split_report_peripheral_event(uint8_t reg, uint8_t type, uint16_t code, int32_t value,
                                             bool sync) {
     LOG_DBG("Got peripheral event for %d!", reg);
     for (size_t i = 0; i < ARRAY_SIZE(proxy_inputs); i++) {
         if (reg == proxy_inputs[i].reg) {
+            if (type == INPUT_EV_KEY) {
+                uint16_t find, replace;
+
+                if (value) {
+                    find = 0;
+                    replace = code;
+                } else {
+                    find = code;
+                    replace = 0;
+                }
+
+                int ret = replace_active_key(i, find, replace);
+                if (ret < 0) {
+                    LOG_WRN("Failed to %s key %d", value ? "track pressed" : "untrack released",
+                            ret);
+                }
+            }
             return input_report(proxy_inputs[i].dev, type, code, value, sync, K_NO_WAIT);
         }
     }
@@ -38,6 +69,37 @@ int zmk_input_split_report_peripheral_event(uint8_t reg, uint8_t type, uint16_t
     return -ENODEV;
 }
 
+int zmk_input_split_peripheral_disconnected(uint8_t reg) {
+    for (size_t i = 0; i < ARRAY_SIZE(proxy_inputs); i++) {
+        if (reg == proxy_inputs[i].reg) {
+            uint16_t prev = 0;
+            for (size_t k = 0; k < CONFIG_ZMK_INPUT_SPLIT_MAX_TRACKED_KEYS; k++) {
+                if (proxy_active_keys[i][k] != 0) {
+                    if (prev != 0) {
+                        int ret = input_report(proxy_inputs[i].dev, INPUT_EV_KEY, prev, 0, false,
+                                               K_NO_WAIT);
+                        if (ret < 0) {
+                            LOG_WRN("Failed to report release event on disconnect (%d)", ret);
+                        }
+                    }
+
+                    prev = proxy_active_keys[i][k];
+                    proxy_active_keys[i][k] = 0;
+                }
+            }
+
+            if (prev != 0) {
+                int ret = input_report(proxy_inputs[i].dev, INPUT_EV_KEY, prev, 0, true, K_NO_WAIT);
+                if (ret < 0) {
+                    LOG_WRN("Failed to report release event on disconnect (%d)", ret);
+                }
+            }
+        }
+    }
+
+    return -ENODEV;
+}
+
 #define ZIS_INST(n)                                                                                \
     DEVICE_DT_INST_DEFINE(n, NULL, NULL, NULL, NULL, POST_KERNEL,                                  \
                           CONFIG_ZMK_INPUT_SPLIT_INIT_PRIORITY, NULL);
@@ -78,4 +140,4 @@ int zmk_input_split_report_peripheral_event(uint8_t reg, uint8_t type, uint16_t
 
 #endif
 
-DT_INST_FOREACH_STATUS_OKAY(ZIS_INST)
+DT_INST_FOREACH_STATUS_OKAY(ZIS_INST)

app/src/split/bluetooth/central.c

@@ -122,7 +122,7 @@ void release_peripheral_input_subs(struct bt_conn *conn) {
     for (size_t i = 0; i < ARRAY_SIZE(peripheral_input_slots); i++) {
         if (peripheral_input_slots[i].conn == conn) {
             peripheral_input_slots[i].conn = NULL;
-            // memset(&peripheral_input_slots[i], 0, sizeof(struct peripheral_input_slot));
+            zmk_input_split_peripheral_disconnected(peripheral_input_slots[i].reg);
         }
     }
 }

app/tests/ble/split/peripheral-input/events.patterns

@@ -1 +1,2 @@
 s/^d_02: @[0-9][0-9]:[0-9][0-9]:[0-9][0-9].[0-9][0-9][0-9][0-9][0-9][0-9]  .{19}/profile 0 /p
+s/^d_00: @[0-9][0-9]:[0-9][0-9]:[0-9][0-9].[0-9][0-9][0-9][0-9][0-9][0-9]  .{19}.*zmk_hid_mouse_button_/mouse button /p

app/tests/ble/split/peripheral-input/peripheral.overlay

@@ -21,6 +21,7 @@
             , <INPUT_EV_REL INPUT_REL_Y 100 1>
             , <INPUT_EV_REL INPUT_REL_X 40 0>
             , <INPUT_EV_REL INPUT_REL_Y 50 1>
+            , <INPUT_EV_KEY INPUT_BTN_1 1 1>
             ;
         exit-after;
     };

app/tests/ble/split/peripheral-input/snapshot.log

@@ -24,3 +24,12 @@ profile 0 <dbg> ble_central: notify_func: payload
 profile 0                    00 64 00 64 00 00 00 00  00                      |.d.d.... .
 profile 0 <dbg> ble_central: notify_func: payload
 profile 0                    00 28 00 32 00 00 00 00  00                      |.(.2.... .
+mouse button press: Button 1 count 1
+mouse button press: Mouse buttons set to 0x02
+profile 0 <dbg> ble_central: notify_func: payload
+profile 0                    02 00 00 00 00 00 00 00  00                      |........ .
+mouse button release: Button 1 count: 0
+mouse button release: Button 1 released
+mouse button release: Mouse buttons set to 0x00
+profile 0 <dbg> ble_central: notify_func: payload
+profile 0                    00 00 00 00 00 00 00 00  00                      |........ .