first commit of GPIO expander

components/services/gpio_exp.h

@@ -0,0 +1,49 @@
+/* GDS 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.
+*/
+#pragma once
+
+#include <stdint.h>
+#include "freertos/FreeRTOS.h"
+#include "driver/gpio.h"
+
+#define GPIO_EXP_BASE_MIN	100
+
+struct gpio_exp_s;
+
+typedef struct {
+	char model[32];
+	uint8_t intr;
+	uint8_t count;
+	uint32_t base;
+	union gpio_exp_phy_u {
+		struct {
+			uint8_t addr, port;
+		};
+		struct {
+			uint8_t cs_pin;
+		};
+	} phy;	
+} gpio_exp_config_t;
+
+typedef void 	   (*gpio_exp_enumerator)(int gpio, int level, struct gpio_exp_s *expander);
+typedef BaseType_t (*gpio_exp_isr)(void *arg);
+
+// set <intr> to -1 and <queue> to NULL if there is no interrupt
+struct gpio_exp_s* gpio_exp_create(const gpio_exp_config_t *config);
+bool               gpio_exp_add_isr(gpio_exp_isr isr, void *arg, struct gpio_exp_s *expander);
+uint32_t           gpio_exp_base(struct gpio_exp_s *expander);
+struct gpio_exp_s* gpio_exp_expander(int gpio);
+
+/* For all functions below when <expander> is provided, GPIO's can be numbered from 0. If <expander>
+   is NULL, then GPIO must start from base */
+struct gpio_exp_s* gpio_exp_set_direction(int gpio, gpio_mode_t mode, struct gpio_exp_s *expander);
+int                gpio_exp_get_level(int gpio, uint32_t age, struct gpio_exp_s *expander);
+/* This can be called to enumerate modified GPIO since last read. Note that <enumerator>
+   can be NULL to initialize all GPIOs */
+void               gpio_exp_enumerate(gpio_exp_enumerator enumerator, struct gpio_exp_s *expander);