From ee137d74b8c13f904160289716fb0d385a39b993 Mon Sep 17 00:00:00 2001
From: Timofey Titovets <nefelim4ag@gmail.com>
Date: Mon, 22 Dec 2025 01:16:59 +0100
Subject: [PATCH] ldc1612: implement 25ms watchdog timeout

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
---
 klippy/extras/probe_eddy_current.py |  3 +++
 src/sensor_ldc1612.c                | 25 +++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/klippy/extras/probe_eddy_current.py b/klippy/extras/probe_eddy_current.py
index 465c9d2c6..5ba22a484 100644
--- a/klippy/extras/probe_eddy_current.py
+++ b/klippy/extras/probe_eddy_current.py
@@ -367,6 +367,7 @@ class EddyGatherSamples:
 class EddyDescend:
     REASON_SENSOR_ERROR = mcu.MCU_trsync.REASON_COMMS_TIMEOUT + 1
     REASON_BUS_IO_ERROR = REASON_SENSOR_ERROR + 12
+    REASON_WATCHDOG_TIMEOUT = REASON_SENSOR_ERROR + 15
     def __init__(self, config, sensor_helper, calibration, param_helper):
         self._printer = config.get_printer()
         self._sensor_helper = sensor_helper
@@ -401,6 +402,8 @@ class EddyDescend:
                     "Communication timeout during homing")
             if res == self.REASON_BUS_IO_ERROR:
                 raise self._printer.command_error("Eddy I2C IO error")
+            if res == self.REASON_WATCHDOG_TIMEOUT:
+                raise self._printer.command_error("Eddy watchdog timeout")
             raise self._printer.command_error("Eddy current sensor error")
         if res != mcu.MCU_trsync.REASON_ENDSTOP_HIT:
             return 0.
diff --git a/src/sensor_ldc1612.c b/src/sensor_ldc1612.c
index 384d89bb3..86ea56039 100644
--- a/src/sensor_ldc1612.c
+++ b/src/sensor_ldc1612.c
@@ -31,6 +31,7 @@ struct ldc1612 {
     struct trsync *ts;
     uint8_t homing_flags;
     uint8_t trigger_reason, error_reason;
+    uint32_t watchdog_deadline;
     uint32_t trigger_threshold;
     uint32_t homing_clock;
 };
@@ -111,6 +112,27 @@ command_query_ldc1612_home_state(uint32_t *args)
 DECL_COMMAND(command_query_ldc1612_home_state,
              "query_ldc1612_home_state oid=%c");
 
+// Default TRSYNC_TIMEOUT, limits ODR > 40
+#define WATCHDOG_TIMEOUT timer_from_us(25000)
+#define WATCHDOG_TIMEOUT_ERROR (0xf)
+
+static void
+watchdog_check(struct ldc1612 *ld)
+{
+    if (!ld->homing_flags)
+        return;
+    if (timer_is_before(timer_read_time(), ld->watchdog_deadline))
+        return;
+    trsync_do_trigger(ld->ts, ld->error_reason + WATCHDOG_TIMEOUT_ERROR);
+    ld->homing_flags = 0;
+}
+
+static void
+watchdog_reset(struct ldc1612 *ld)
+{
+    ld->watchdog_deadline = timer_read_time() + WATCHDOG_TIMEOUT;
+}
+
 #define DATA_ERROR_AMPLITUDE   (1 << 0)
 #define DATA_ERROR_WATCHDOG    (1 << 1)
 #define DATA_ERROR_OVER_RANGE  (1 << 2)
@@ -203,6 +225,7 @@ ldc1612_query(struct ldc1612 *ld, uint8_t oid)
     irq_disable();
     ld->flags &= ~LDC_PENDING;
     irq_enable();
+    watchdog_check(ld);
     // Force data read on I2C error or Zero Count
     if (!(status & (STATUS_DRDY | STATUS_I2C_ERROR | STATUS_ZERO_COUNT)))
         return;
@@ -225,6 +248,7 @@ ldc1612_query(struct ldc1612 *ld, uint8_t oid)
                     | ((uint32_t)d[2] << 8)
                     | ((uint32_t)d[3]);
     check_home(ld, data);
+    watchdog_reset(ld);
 
     // Flush local buffer if needed
     if (ld->sb.data_count + BYTES_PER_SAMPLE > ARRAY_SIZE(ld->sb.data))
@@ -248,6 +272,7 @@ command_query_ldc1612(uint32_t *args)
     irq_disable();
     ld->timer.waketime = timer_read_time() + ld->rest_ticks;
     sched_add_timer(&ld->timer);
+    watchdog_reset(ld);
     irq_enable();
 }
 DECL_COMMAND(command_query_ldc1612, "query_ldc1612 oid=%c rest_ticks=%u");