lp-i2c: Added support for LP I2C peripheral to LP core

This commit adds support for the LP I2C peripheral driver to be used by
the LP core. An example is also added to demonstrate the usage of the LP
I2C peripheral from the LP core.

components/ulp/lp_core/include/lp_core_i2c.h

@@ -0,0 +1,77 @@
+/*
+ * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+#include "hal/i2c_types.h"
+#include "hal/gpio_types.h"
+#include "esp_err.h"
+
+typedef struct {
+    gpio_num_t sda_io_num;      // GPIO pin for SDA signal. Only GPIO#6 can be used as the SDA pin.
+    gpio_num_t scl_io_num;      // GPIO pin for SCL signal. Only GPIO#7 can be used as the SCL pin.
+    bool sda_pullup_en;         // SDA line enable internal pullup. Can be configured if external pullup is not used.
+    bool scl_pullup_en;         // SCL line enable internal pullup. Can be configured if external pullup is not used.
+} lp_core_i2c_pin_cfg_t;
+
+typedef struct {
+    uint32_t clk_speed_hz;      // LP I2C clock speed for master mode
+} lp_core_i2c_timing_cfg_t;
+
+typedef struct {
+    lp_core_i2c_pin_cfg_t i2c_pin_cfg;        // LP I2C pin configuration
+    lp_core_i2c_timing_cfg_t i2c_timing_cfg;  // LP I2C timing configuration
+    soc_periph_lp_i2c_clk_src_t i2c_src_clk;  // LP I2C source clock type
+} lp_core_i2c_cfg_t;
+
+/* Default LP I2C GPIO settings */
+#define LP_I2C_DEFAULT_GPIO_CONFIG()            \
+        .i2c_pin_cfg.sda_io_num = GPIO_NUM_6,   \
+        .i2c_pin_cfg.scl_io_num = GPIO_NUM_7,   \
+        .i2c_pin_cfg.sda_pullup_en = true,      \
+        .i2c_pin_cfg.scl_pullup_en = true,      \
+
+/* LP I2C fast mode config. Max SCL freq of 400 KHz. */
+#define LP_I2C_FAST_MODE_CONFIG()               \
+        .i2c_timing_cfg.clk_speed_hz = 400000,  \
+
+/* LP I2C standard mode config. Max SCL freq of 100 KHz. */
+#define LP_I2C_STANDARD_MODE_CONFIG()           \
+        .i2c_timing_cfg.clk_speed_hz = 100000,  \
+
+#define LP_I2C_DEFAULT_SRC_CLK()                \
+        .i2c_src_clk = LP_I2C_SCLK_LP_FAST,     \
+
+/* Default LP I2C GPIO settings and timing parametes */
+#define LP_CORE_I2C_DEFAULT_CONFIG()            \
+    {                                           \
+        LP_I2C_DEFAULT_GPIO_CONFIG()            \
+        LP_I2C_FAST_MODE_CONFIG()               \
+        LP_I2C_DEFAULT_SRC_CLK()                \
+    }
+
+/**
+ * @brief Initialize and configure the LP I2C for use by the LP core
+ * Currently LP I2C can only be used in master mode
+ *
+ * @param cfg           Configuration parameters
+ * @return esp_err_t    ESP_OK when successful
+ *
+ * @note The internal pull-up resistors for SDA and SCL pins, if enabled, will
+ * provide a weak pull-up value of about 30-50 kOhm. Users are adviced to enable
+ * external pull-ups for better performance at higher SCL frequencies.
+ */
+esp_err_t lp_core_i2c_master_init(i2c_port_t lp_i2c_num, const lp_core_i2c_cfg_t *cfg);
+
+#ifdef __cplusplus
+}
+#endif