From dd054efe8d6dc40a22dc7c7be26ba6eebbdca02b Mon Sep 17 00:00:00 2001
From: David Volovskiy <devolov@gmail.com>
Date: Sun, 16 Nov 2025 16:05:22 -0500
Subject: [PATCH] Added LIR latching on LIS2DW

---
 movement.c                           |  3 ++-
 watch-library/shared/driver/lis2dw.c | 31 ++++++++++++++++++++++++++--
 watch-library/shared/driver/lis2dw.h | 14 +++++++++++--
 3 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/movement.c b/movement.c
index 345dcb34..a3a61233 100644
--- a/movement.c
+++ b/movement.c
@@ -816,6 +816,7 @@ bool movement_enable_tap_detection_if_available(void) {
         lis2dw_set_data_rate(LIS2DW_DATA_RATE_HP_400_HZ);
         lis2dw_set_mode(LIS2DW_MODE_LOW_POWER);
         lis2dw_enable_double_tap();
+        lis2dw12_int_notification_set(LIS2DW12_INT_LATCHED);
 
         // Settling time (1 sample duration, i.e. 1/400Hz)
         delay_ms(3);
@@ -836,6 +837,7 @@ bool movement_disable_tap_detection_if_available(void) {
         lis2dw_set_data_rate(movement_state.accelerometer_background_rate);
         lis2dw_set_mode(LIS2DW_MODE_LOW_POWER);
         lis2dw_disable_double_tap();
+        lis2dw12_int_notification_set(LIS2DW12_INT_PULSED);
         // ...disable Z axis (not sure if this is needed, does this save power?)...
         lis2dw_configure_tap_threshold(0, 0, 0, 0);
 
@@ -1118,7 +1120,6 @@ void app_setup(void) {
             watch_register_interrupt_callback(HAL_GPIO_A3_pin(), cb_accelerometer_event, INTERRUPT_TRIGGER_RISING);
 
             // Enable the interrupts...
-            lis2dw_latched_interrupts();
             lis2dw_enable_interrupts();
 
             // At first boot, this next line sets the accelerometer's sampling rate to 0, which is LIS2DW_DATA_RATE_POWERDOWN.
diff --git a/watch-library/shared/driver/lis2dw.c b/watch-library/shared/driver/lis2dw.c
index 6e3cb59a..339af08d 100644
--- a/watch-library/shared/driver/lis2dw.c
+++ b/watch-library/shared/driver/lis2dw.c
@@ -411,6 +411,33 @@ void lis2dw_configure_int2(uint8_t sources) {
 #endif
 }
 
+void lis2dw12_int_notification_set(lis2dw12_lir_t val) {
+#ifdef I2C_SERCOM
+    uint8_t configuration = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL3);
+    if (val == LIS2DW12_INT_LATCHED) {
+        configuration |= LIS2DW_CTRL3_VAL_LIR;
+    } else {
+        configuration &= ~LIS2DW_CTRL7_VAL_DRDY_PULSED;
+    }
+    watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL3, configuration);
+#else
+    (void)val;
+#endif
+}
+
+lis2dw12_lir_t lis2dw12_int_notification_get(void) {
+#ifdef I2C_SERCOM
+    uint8_t configuration = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL3);
+    if (configuration & LIS2DW12_INT_LATCHED) {
+        return LIS2DW12_INT_LATCHED;
+    } else {
+        return LIS2DW12_INT_PULSED;
+    }
+#else
+    return LIS2DW12_INT_PULSED;
+#endif
+}
+
 void lis2dw_enable_interrupts(void) {
 #ifdef I2C_SERCOM
     uint8_t configuration = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL7);
@@ -425,14 +452,14 @@ void lis2dw_disable_interrupts(void) {
 #endif
 }
 
-void lis2dw_pulsed_interrupts(void) {
+void lis2dw_pulsed_drdy_interrupts(void) {
 #ifdef I2C_SERCOM
     uint8_t configuration = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL7);
     watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL7, configuration | LIS2DW_CTRL7_VAL_DRDY_PULSED);
 #endif
 }
 
-void lis2dw_latched_interrupts(void) {
+void lis2dw_latched_drdy_interrupts(void) {
 #ifdef I2C_SERCOM
     uint8_t configuration = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL7);
     watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL7, configuration & ~LIS2DW_CTRL7_VAL_DRDY_PULSED);
diff --git a/watch-library/shared/driver/lis2dw.h b/watch-library/shared/driver/lis2dw.h
index 2db57da1..f7b0a801 100644
--- a/watch-library/shared/driver/lis2dw.h
+++ b/watch-library/shared/driver/lis2dw.h
@@ -92,6 +92,12 @@ typedef enum {
   LIS2DW_FILTER_HIGH_PASS = 1,
 } lis2dw_filter_t;
 
+typedef enum
+{
+  LIS2DW12_INT_PULSED   = 0,
+  LIS2DW12_INT_LATCHED  = 1,
+} lis2dw12_lir_t;
+
 typedef enum {
   LIS2DW_RANGE_16_G = 0b11, // +/- 16g
   LIS2DW_RANGE_8_G = 0b10,  // +/- 8g
@@ -367,6 +373,10 @@ void lis2dw_configure_tap_threshold(uint8_t threshold_x, uint8_t threshold_y, ui
 
 void lis2dw_configure_tap_duration(uint8_t latency, uint8_t quiet, uint8_t shock);
 
+void lis2dw12_int_notification_set(lis2dw12_lir_t val);
+
+lis2dw12_lir_t lis2dw12_int_notification_get(void);
+
 void lis2dw_configure_int1(uint8_t sources);
 
 void lis2dw_configure_int2(uint8_t sources);
@@ -375,9 +385,9 @@ void lis2dw_enable_interrupts(void);
 
 void lis2dw_disable_interrupts(void);
 
-void lis2dw_pulsed_interrupts(void);
+void lis2dw_pulsed_drdy_interrupts(void);
 
-void lis2dw_latched_interrupts(void);
+void lis2dw_latched_drdy_interrupts(void);
 
 lis2dw_interrupt_source_t lis2dw_get_interrupt_source(void);