From 46ff88717ca78f5a39b72fa2bc3a2b96a84fc8da Mon Sep 17 00:00:00 2001
From: hebinglin <hebinglin@espressif.com>
Date: Fri, 5 Jun 2026 20:01:15 +0800
Subject: [PATCH] fix(ulp): fix lp uart keep wakeup triggered

---
 .../esp32c5/include/soc/Kconfig.soc_caps.in   |  4 +++
 components/soc/esp32c5/include/soc/soc_caps.h |  1 +
 .../esp32c6/include/soc/Kconfig.soc_caps.in   |  4 +++
 components/soc/esp32c6/include/soc/soc_caps.h |  1 +
 .../esp32p4/include/soc/Kconfig.soc_caps.in   |  4 +++
 components/soc/esp32p4/include/soc/soc_caps.h |  1 +
 .../esp32s31/include/soc/Kconfig.soc_caps.in  |  4 +++
 .../soc/esp32s31/include/soc/soc_caps.h       |  1 +
 .../ulp/lp_core/lp_core/lp_core_utils.c       | 26 ++++++++++++-------
 .../include/ulp_lp_core_lp_uart_shared.h      |  9 ++++---
 .../main/lp_core/test_main_uart_wakeup.c      | 10 +++----
 docs/en/api-reference/system/sleep_modes.rst  |  6 +++--
 .../api-reference/system/sleep_modes.rst      |  6 +++--
 .../main/lp_core/main.c                       |  9 +++----
 14 files changed, 57 insertions(+), 29 deletions(-)

diff --git a/components/soc/esp32c5/include/soc/Kconfig.soc_caps.in b/components/soc/esp32c5/include/soc/Kconfig.soc_caps.in
index 91063efa613..3440d12e43a 100644
--- a/components/soc/esp32c5/include/soc/Kconfig.soc_caps.in
+++ b/components/soc/esp32c5/include/soc/Kconfig.soc_caps.in
@@ -1606,3 +1606,7 @@ config SOC_LP_CORE_SUPPORT_I2C
 config SOC_LP_CORE_HW_AUTO_CLRWAKEUPCAUSE
     bool
     default y
+
+config SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED
+    bool
+    default y
diff --git a/components/soc/esp32c5/include/soc/soc_caps.h b/components/soc/esp32c5/include/soc/soc_caps.h
index ae82fe8a1e2..c90fb873eff 100644
--- a/components/soc/esp32c5/include/soc/soc_caps.h
+++ b/components/soc/esp32c5/include/soc/soc_caps.h
@@ -639,3 +639,4 @@
 #define SOC_LP_CORE_SUPPORT_STORE_LOAD_EXCEPTIONS   (1) /*!< LP Core will raise exceptions if accessing invalid addresses */
 #define SOC_LP_CORE_SUPPORT_I2C                     (1) /*!< LP Core supports I2C */
 #define SOC_LP_CORE_HW_AUTO_CLRWAKEUPCAUSE          (1) /*!< LP core requests sleep, PMU clears both HP and LP wakeup causes */
+#define SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED   (1) /*!< LP UART wakeup source is kept triggered */
diff --git a/components/soc/esp32c6/include/soc/Kconfig.soc_caps.in b/components/soc/esp32c6/include/soc/Kconfig.soc_caps.in
index 36a8f2f068e..976f556501f 100644
--- a/components/soc/esp32c6/include/soc/Kconfig.soc_caps.in
+++ b/components/soc/esp32c6/include/soc/Kconfig.soc_caps.in
@@ -1343,6 +1343,10 @@ config SOC_LP_CORE_HW_AUTO_CLRWAKEUPCAUSE
     bool
     default y
 
+config SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED
+    bool
+    default y
+
 config SOC_DEBUG_HAVE_OCD_STUB_BINS
     bool
     default y
diff --git a/components/soc/esp32c6/include/soc/soc_caps.h b/components/soc/esp32c6/include/soc/soc_caps.h
index 88f51d69f1a..09bec1f163f 100644
--- a/components/soc/esp32c6/include/soc/soc_caps.h
+++ b/components/soc/esp32c6/include/soc/soc_caps.h
@@ -544,6 +544,7 @@
 #define SOC_LP_CORE_SUPPORT_ETM               (1) /*!< LP Core supports ETM */
 #define SOC_LP_CORE_SUPPORT_I2C               (1) /*!< LP Core supports I2C */
 #define SOC_LP_CORE_HW_AUTO_CLRWAKEUPCAUSE    (1) /*!< LP core requests sleep, PMU clears both HP and LP wakeup causes */
+#define SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED   (1) /*!< LP UART wakeup source is kept triggered */
 
 /*------------------------------------- DEBUG CAPS -------------------------------------*/
 #define SOC_DEBUG_HAVE_OCD_STUB_BINS    (1)
diff --git a/components/soc/esp32p4/include/soc/Kconfig.soc_caps.in b/components/soc/esp32p4/include/soc/Kconfig.soc_caps.in
index a49d6378765..8e1f7041273 100644
--- a/components/soc/esp32p4/include/soc/Kconfig.soc_caps.in
+++ b/components/soc/esp32p4/include/soc/Kconfig.soc_caps.in
@@ -1922,3 +1922,7 @@ config SOC_LP_CORE_SUPPORT_I2C
 config SOC_LP_CORE_HW_AUTO_CLRWAKEUPCAUSE
     bool
     default y
+
+config SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED
+    bool
+    default y
diff --git a/components/soc/esp32p4/include/soc/soc_caps.h b/components/soc/esp32p4/include/soc/soc_caps.h
index 5eade623e78..121bbe74711 100644
--- a/components/soc/esp32p4/include/soc/soc_caps.h
+++ b/components/soc/esp32p4/include/soc/soc_caps.h
@@ -735,3 +735,4 @@
 #define SOC_LP_CORE_SUPPORT_STORE_LOAD_EXCEPTIONS   (1) /*!< LP Core will raise exceptions if accessing invalid addresses */
 #define SOC_LP_CORE_SUPPORT_I2C                     (1) /*!< LP Core supports I2C */
 #define SOC_LP_CORE_HW_AUTO_CLRWAKEUPCAUSE          (1) /*!< LP core requests sleep, PMU clears both HP and LP wakeup causes */
+#define SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED   (1) /*!< LP UART wakeup source is kept triggered */
diff --git a/components/soc/esp32s31/include/soc/Kconfig.soc_caps.in b/components/soc/esp32s31/include/soc/Kconfig.soc_caps.in
index 4aed35e6376..d0e9bdf51b4 100644
--- a/components/soc/esp32s31/include/soc/Kconfig.soc_caps.in
+++ b/components/soc/esp32s31/include/soc/Kconfig.soc_caps.in
@@ -1547,6 +1547,10 @@ config SOC_LP_CORE_HAS_PMP
     bool
     default y
 
+config SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED
+    bool
+    default y
+
 config SOC_LP_TIMER_BIT_WIDTH_LO
     int
     default 32
diff --git a/components/soc/esp32s31/include/soc/soc_caps.h b/components/soc/esp32s31/include/soc/soc_caps.h
index eb9ae8eaa7f..91b7a0f98a1 100644
--- a/components/soc/esp32s31/include/soc/soc_caps.h
+++ b/components/soc/esp32s31/include/soc/soc_caps.h
@@ -576,6 +576,7 @@
 #define SOC_LP_CORE_SUPPORT_I2C                     (1) /*!< LP Core supports I2C */
 #define SOC_LP_CORE_HW_AUTO_CLRWAKEUPCAUSE          (1) /*!< LP core requests sleep, PMU clears both HP and LP wakeup causes */
 #define SOC_LP_CORE_HAS_PMP                         (1) /*!< LP Core RISC-V has 16 PMP entries (128-byte granularity, RISC-V v1.10) */
+#define SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED   (1) /*!< LP UART wakeup source is kept triggered */
 
 /*-------------------------- LP_TIMER CAPS ----------------------------------*/
 #define SOC_LP_TIMER_BIT_WIDTH_LO           32 // Bit width of lp_timer low part
diff --git a/components/ulp/lp_core/lp_core/lp_core_utils.c b/components/ulp/lp_core/lp_core/lp_core_utils.c
index 2ba6464aeec..dc987c272cb 100644
--- a/components/ulp/lp_core/lp_core/lp_core_utils.c
+++ b/components/ulp/lp_core/lp_core/lp_core_utils.c
@@ -25,6 +25,8 @@
 
 #include "esp_cpu.h"
 #include "ulp_lp_core_cpu_freq_shared.h"
+#include "ulp_lp_core_lp_uart_shared.h"
+#include "ulp_lp_core_uart.h"
 #if SOC_LP_CORE_HW_AUTO_CLRWAKEUPCAUSE
 #include "hal/lp_aon_hal.h"
 #include "rom/rtc.h"
@@ -32,6 +34,14 @@
 
 static uint32_t lp_wakeup_cause = 0;
 
+#if SOC_ULP_LP_UART_SUPPORTED
+void ulp_lp_core_lp_uart_reset_wakeup_en(void)
+{
+    lp_core_ll_enable_lp_uart_wakeup(false);
+    lp_core_ll_enable_lp_uart_wakeup(true);
+}
+#endif
+
 void ulp_lp_core_update_wakeup_cause(void)
 {
     lp_wakeup_cause = 0;
@@ -46,6 +56,13 @@ void ulp_lp_core_update_wakeup_cause(void)
             && (uart_ll_get_intraw_mask(&LP_UART) & LP_UART_WAKEUP_INT_RAW)) {
         lp_wakeup_cause |= LP_CORE_LL_WAKEUP_SOURCE_LP_UART;
         uart_ll_clr_intsts_mask(&LP_UART, LP_UART_WAKEUP_INT_CLR);
+#if SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED
+        // In these chips, the LP UART wakeup source is kept triggered, so we need to
+        // reset the wakeup register and flush the UART buffer manually after waking up.
+        lp_core_uart_tx_flush(LP_UART_NUM_0);
+        lp_core_uart_clear_buf();
+        ulp_lp_core_lp_uart_reset_wakeup_en();
+#endif
     }
 #endif
 
@@ -141,15 +158,6 @@ void ulp_lp_core_delay_cycles(uint32_t cycles)
     }
 }
 
-#if SOC_ULP_LP_UART_SUPPORTED
-
-void ulp_lp_core_lp_uart_reset_wakeup_en(void)
-{
-    lp_core_ll_enable_lp_uart_wakeup(false);
-    lp_core_ll_enable_lp_uart_wakeup(true);
-}
-#endif
-
 void ulp_lp_core_sleep_start_lp_core(void)
 {
 #if SOC_LP_CORE_HW_AUTO_CLRWAKEUPCAUSE
diff --git a/components/ulp/lp_core/shared/include/ulp_lp_core_lp_uart_shared.h b/components/ulp/lp_core/shared/include/ulp_lp_core_lp_uart_shared.h
index 63ff39d0f7d..c51bf35ae8b 100644
--- a/components/ulp/lp_core/shared/include/ulp_lp_core_lp_uart_shared.h
+++ b/components/ulp/lp_core/shared/include/ulp_lp_core_lp_uart_shared.h
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2024-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -19,9 +19,10 @@ extern "C" {
  *
  * @note This function configures the LP UART wakeup mode. Ensure that the UART has already been initialized
  *       with the lp_core_uart_init() call.
- *       Once the LP Core wakes up due to the LP UART, the wakeup feature is disabled.
- *       To re-enable the wakeup from the LP UART, you must call
- *       ulp_lp_core_lp_uart_reset_wakeup_en() again before the LP core goes to sleep.
+ *       Once the LP Core wakes up due to the LP UART, the wakeup will be kept triggered in the chips with
+ *       SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED. You need to call ulp_lp_core_lp_uart_reset_wakeup_en()
+ *       to reset the wakeup signal and the UART buffer manually after waking up, which is done in ulp
+ *       startup phase.
  *       Also be aware of limitations in different modes mentioned in the uart_wakeup_cfg_t struct.
  *
  *
diff --git a/components/ulp/test_apps/lp_core/lp_core_basic_tests/main/lp_core/test_main_uart_wakeup.c b/components/ulp/test_apps/lp_core/lp_core_basic_tests/main/lp_core/test_main_uart_wakeup.c
index 54e2f691881..aecb478f326 100644
--- a/components/ulp/test_apps/lp_core/lp_core_basic_tests/main/lp_core/test_main_uart_wakeup.c
+++ b/components/ulp/test_apps/lp_core/lp_core_basic_tests/main/lp_core/test_main_uart_wakeup.c
@@ -1,19 +1,17 @@
 /*
- * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2024-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
 
 #include "ulp_lp_core_utils.h"
 #include "ulp_lp_core_print.h"
-#include "ulp_lp_core_lp_uart_shared.h"
-#include "lp_core_uart.h"
 #include "ulp_lp_core_uart.h"
 
 int main(void)
 {
     lp_core_printf("Hello world\r\n");
-    ulp_lp_core_delay_us(5000);
-    lp_core_uart_clear_buf();
-    ulp_lp_core_lp_uart_reset_wakeup_en();
+    lp_core_uart_tx_flush(LP_UART_NUM_0);
+
+    return 0;
 }
diff --git a/docs/en/api-reference/system/sleep_modes.rst b/docs/en/api-reference/system/sleep_modes.rst
index 65b57286c60..e7f50c1ce46 100644
--- a/docs/en/api-reference/system/sleep_modes.rst
+++ b/docs/en/api-reference/system/sleep_modes.rst
@@ -454,9 +454,11 @@ The UART wakeup supports the following modes:
     #. Initialize the LP UART (call :cpp:func:`lp_core_uart_init`).
     #. Configure the LP_UART wakeup mode using the :cpp:func:`lp_core_uart_wakeup_setup` function with a :cpp:type:`uart_wakeup_cfg_t` structure, using the same configuration method as HP UART.
 
-    .. note::
+    .. only:: SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED
 
-        Once the LP core wakes up due to LP_UART, you must call :cpp:func:`ulp_lp_core_lp_uart_reset_wakeup_en` or reset the LP UART module to clear the wakeup signal before the LP core goes to sleep, otherwise, it will be repeated wakeup.
+       .. note::
+
+           On chips with ``SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED``, the LP UART wakeup signal remains triggered after a wakeup event. The LP core startup flow (:cpp:func:`ulp_lp_core_update_wakeup_cause`) automatically calls :cpp:func:`ulp_lp_core_lp_uart_reset_wakeup_en` and :cpp:func:`lp_core_uart_clear_buf` to clear this state. If the standard startup flow is not used, you must handle this manually; otherwise, repeated wakeups will occur.
 
     For example code on LP_UART wakeup, refer to :example:`system/ulp/lp_core/lp_uart/lp_uart_char_seq_wakeup`.
 
diff --git a/docs/zh_CN/api-reference/system/sleep_modes.rst b/docs/zh_CN/api-reference/system/sleep_modes.rst
index d0d06ec4c62..8a2ffd80620 100644
--- a/docs/zh_CN/api-reference/system/sleep_modes.rst
+++ b/docs/zh_CN/api-reference/system/sleep_modes.rst
@@ -454,9 +454,11 @@ UART 唤醒支持以下模式：
     #. 初始化 LP UART（调用 :cpp:func:`lp_core_uart_init`）。
     #. 使用 :cpp:func:`lp_core_uart_wakeup_setup` 函数配置 LP_UART 的唤醒模式，参数使用 :cpp:type:`uart_wakeup_cfg_t` 结构体，配置方式与 HP UART 相同。
 
-    .. note::
+    .. only:: SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED
 
-        当 LP 核因 LP_UART 唤醒后，必须在 LP 核进入睡眠前调用 :cpp:func:`ulp_lp_core_lp_uart_reset_wakeup_en` 函数或是复位整个 LP UART 模块以清除唤醒信号，否则会被重复唤醒。
+       .. note::
+
+           在支持 ``SOC_LP_CORE_LP_UART_WAKEUP_KEEP_TRIGGERED`` 的芯片上，LP UART 唤醒后唤醒信号会保持触发状态。LP 核启动流程（:cpp:func:`ulp_lp_core_update_wakeup_cause`）会自动调用 :cpp:func:`ulp_lp_core_lp_uart_reset_wakeup_en` 和 :cpp:func:`lp_core_uart_clear_buf` 清除该状态。若未走标准启动流程，则需手动处理，否则会被重复唤醒。
 
     有关 LP_UART 唤醒的示例代码，请参考 :example:`system/ulp/lp_core/lp_uart/lp_uart_char_seq_wakeup`。
 
diff --git a/examples/system/ulp/lp_core/lp_uart/lp_uart_char_seq_wakeup/main/lp_core/main.c b/examples/system/ulp/lp_core/lp_uart/lp_uart_char_seq_wakeup/main/lp_core/main.c
index 0bc04ec231b..237842c54c1 100644
--- a/examples/system/ulp/lp_core/lp_uart/lp_uart_char_seq_wakeup/main/lp_core/main.c
+++ b/examples/system/ulp/lp_core/lp_uart/lp_uart_char_seq_wakeup/main/lp_core/main.c
@@ -1,20 +1,17 @@
 /*
- * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2024-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
 
 #include "ulp_lp_core_utils.h"
 #include "ulp_lp_core_print.h"
-#include "ulp_lp_core_lp_uart_shared.h"
+#include "ulp_lp_core_uart.h"
 
 int main (void)
 {
     lp_core_printf("Hello world\r\n");
+    lp_core_uart_tx_flush(LP_UART_NUM_0);
 
-    // If you want to make it possible to wake up from UART after sleep,
-    // you have to reset the wakeup register and the UART buffer manually.
-    // ulp_lp_core_lp_uart_reset_wakeup_en();
-    // lp_core_uart_clear_buf();
     return 0;
 }