feat(lp_core): added support for LP-IO as LP-core wakeup source

components/hal/esp32c6/include/hal/rtc_io_ll.h

@@ -309,6 +309,14 @@ static inline void rtcio_ll_wakeup_enable(int rtcio_num, rtcio_ll_wake_type_t ty
 {
     LP_IO.pin[rtcio_num].wakeup_enable = 1;
     LP_IO.pin[rtcio_num].int_type = type;
+
+    /* Work around for HW issue,
+       need to also enable this clk, otherwise it will
+       not trigger a wake-up on the ULP. This is not needed
+       for triggering a wakeup on HP CPU, but always setting this
+       has no side-effects.
+    */
+    LP_IO.date.clk_en = 1;
 }
 
 /**

components/ulp/lp_core/lp_core.c

@@ -130,7 +130,7 @@ esp_err_t ulp_lp_core_run(ulp_lp_core_cfg_t* cfg)
     }
 #endif
 
-    if (cfg->wakeup_source & (ULP_LP_CORE_WAKEUP_SOURCE_LP_UART | ULP_LP_CORE_WAKEUP_SOURCE_LP_IO)) {
+    if (cfg->wakeup_source & (ULP_LP_CORE_WAKEUP_SOURCE_LP_UART)) {
         ESP_LOGE(TAG, "Wake-up source not yet supported");
         return ESP_ERR_INVALID_ARG;
     }

examples/system/.build-test-rules.yml

@@ -299,6 +299,12 @@ examples/system/ulp/lp_core/gpio_intr_pulse_counter:
   depends_components:
     - ulp
 
+examples/system/ulp/lp_core/gpio_wakeup:
+  enable:
+    - if: (SOC_LP_CORE_SUPPORTED == 1) and (SOC_RTCIO_PIN_COUNT > 0)
+  depends_components:
+    - ulp
+
 examples/system/ulp/lp_core/inter_cpu_critical_section/:
   enable:
     - if: SOC_LP_CORE_SUPPORTED == 1

examples/system/ulp/lp_core/gpio_wakeup/CMakeLists.txt

@@ -0,0 +1,6 @@
+# The following lines of boilerplate have to be in your project's CMakeLists
+# in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.16)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+project(ulp_lp_core_gpio_wakeup_example)

examples/system/ulp/lp_core/gpio_wakeup/README.md

@@ -0,0 +1,26 @@
+| Supported Targets | ESP32-C5 | ESP32-C6 | ESP32-P4 |
+| ----------------- | -------- | -------- | -------- |
+# ULP-LP-Core simple example with GPIO Interrupt:
+
+This example demonstrates how to program the LP-Core coprocessor to wake up from a RTC IO interrupt, instead of waking periodically from the ULP timer.
+
+ULP program written in C can be found across `ulp/main.c`. The build system compiles and links this program, converts it into binary format, and embeds it into the .rodata section of the ESP-IDF application.
+
+At runtime, the main code running on the ESP (found in lp_core_gpio_wake_up_example_main.c) loads ULP program into the `RTC_SLOW_MEM` memory region using `ulp_lp_core_load_binary` function. The main code then configures the ULP GPIO wakeup source and starts the coprocessor by using `ulp_lp_core_run` followed by putting the chip into deep sleep mode.
+
+When the wakeup source pin is pulled low the LP-Core coprocessor is woken up, sends a wakeup signal to the main CPU and goes back to sleep again.
+
+In this example the input signal is connected to GPIO2. To change the pin number, check the Chip Pin List document and adjust `WAKEUP_PIN` variable in main.c.
+
+
+## Example output
+
+```
+Not a LP-Core wakeup, initializing it!
+Entering deep sleep
+
+...
+
+LP-Core woke up the main CPU!
+Entering deep sleep
+```

examples/system/ulp/lp_core/gpio_wakeup/main/CMakeLists.txt

@@ -0,0 +1,27 @@
+# Set usual component variables
+set(COMPONENT_SRCS "lp_core_gpio_wake_up_example_main.c")
+set(COMPONENT_ADD_INCLUDEDIRS "")
+set(COMPONENT_REQUIRES ulp driver)
+
+register_component()
+
+#
+# ULP support additions to component CMakeLists.txt.
+#
+# 1. The ULP app name must be unique (if multiple components use ULP).
+set(ulp_app_name ulp_${COMPONENT_NAME})
+#
+# 2. Specify all C and Assembly source files.
+#    Files should be placed into a separate directory (in this case, ulp/),
+#    which should not be added to COMPONENT_SRCS.
+set(ulp_riscv_sources "ulp/main.c")
+
+#
+# 3. List all the component source files which include automatically
+#    generated ULP export file, ${ulp_app_name}.h:
+set(ulp_exp_dep_srcs "lp_core_gpio_wake_up_example_main.c")
+
+#
+# 4. Call function to build ULP binary and embed in project using the argument
+#    values above.
+ulp_embed_binary(${ulp_app_name} "${ulp_riscv_sources}" "${ulp_exp_dep_srcs}")

examples/system/ulp/lp_core/gpio_wakeup/main/lp_core_gpio_wake_up_example_main.c

@@ -0,0 +1,86 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+/* ULP LP-Core GPIO wake-up example
+
+   This example code is in the Public Domain (or CC0 licensed, at your option.)
+
+   Unless required by applicable law or agreed to in writing, this
+   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+   CONDITIONS OF ANY KIND, either express or implied.
+*/
+
+#include <stdio.h>
+#include "esp_sleep.h"
+#include "driver/rtc_io.h"
+#include "ulp_lp_core.h"
+#include "ulp_main.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+
+#define WAKEUP_PIN 2
+
+extern const uint8_t ulp_main_bin_start[] asm("_binary_ulp_main_bin_start");
+extern const uint8_t ulp_main_bin_end[]   asm("_binary_ulp_main_bin_end");
+
+static void init_ulp_program(void);
+
+static void wakeup_gpio_init(void)
+{
+    /* Configure the button GPIO as input, enable wakeup */
+    rtc_gpio_init(WAKEUP_PIN);
+    rtc_gpio_set_direction(WAKEUP_PIN, RTC_GPIO_MODE_INPUT_ONLY);
+    rtc_gpio_pulldown_dis(WAKEUP_PIN);
+    rtc_gpio_pullup_en(WAKEUP_PIN);
+    rtc_gpio_wakeup_enable(WAKEUP_PIN, GPIO_INTR_LOW_LEVEL);
+}
+
+void app_main(void)
+{
+    /* If user is using USB-serial-jtag then idf monitor needs some time to
+    *  re-connect to the USB port. We wait 1 sec here to allow for it to make the reconnection
+    *  before we print anything. Otherwise the chip will go back to sleep again before the user
+    *  has time to monitor any output.
+    */
+    vTaskDelay(pdMS_TO_TICKS(1000));
+
+    wakeup_gpio_init();
+
+    esp_sleep_wakeup_cause_t cause = esp_sleep_get_wakeup_cause();
+    /* not a wakeup from ULP, load the firmware */
+    if (cause != ESP_SLEEP_WAKEUP_ULP) {
+        printf("Not a ULP wakeup, initializing it! \n");
+        init_ulp_program();
+    }
+
+    /* ULP read and detected a change in WAKEUP_PIN, prints */
+    if (cause == ESP_SLEEP_WAKEUP_ULP) {
+        printf("ULP woke up the main CPU! \n");
+    }
+
+    /* Go back to sleep, only the ULP will run */
+    printf("Entering deep sleep\n\n");
+
+    /* Small delay to ensure the messages are printed */
+    vTaskDelay(100 / portTICK_PERIOD_MS);
+
+    ESP_ERROR_CHECK( esp_sleep_enable_ulp_wakeup());
+
+    esp_deep_sleep_start();
+}
+
+static void init_ulp_program(void)
+{
+    esp_err_t err = ulp_lp_core_load_binary(ulp_main_bin_start, (ulp_main_bin_end - ulp_main_bin_start));
+    ESP_ERROR_CHECK(err);
+
+    /* Start the program */
+    ulp_lp_core_cfg_t cfg = {
+        .wakeup_source = ULP_LP_CORE_WAKEUP_SOURCE_LP_IO,
+    };
+
+    err = ulp_lp_core_run(&cfg);
+    ESP_ERROR_CHECK(err);
+}

examples/system/ulp/lp_core/gpio_wakeup/main/ulp/main.c

@@ -0,0 +1,23 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include <stdint.h>
+#include <stdbool.h>
+#include "ulp_lp_core.h"
+#include "ulp_lp_core_utils.h"
+#include "ulp_lp_core_gpio.h"
+
+
+int main (void)
+{
+    ulp_lp_core_wakeup_main_processor();
+
+    /* Wakeup interrupt is a level interrupt, wait 1 sec to
+        allow user to release button to avoid waking up the ULP multiple times */
+    ulp_lp_core_delay_us(1000*1000);
+    ulp_lp_core_gpio_clear_intr_status();
+
+    return 0;
+}

examples/system/ulp/lp_core/gpio_wakeup/sdkconfig.defaults

@@ -0,0 +1,9 @@
+# Enable ULP
+CONFIG_ULP_COPROC_ENABLED=y
+CONFIG_ULP_COPROC_TYPE_LP_CORE=y
+CONFIG_ULP_COPROC_RESERVE_MEM=8128
+# Set log level to Warning to produce clean output
+CONFIG_BOOTLOADER_LOG_LEVEL_WARN=y
+CONFIG_BOOTLOADER_LOG_LEVEL=2
+CONFIG_LOG_DEFAULT_LEVEL_WARN=y
+CONFIG_LOG_DEFAULT_LEVEL=2