Drivers: i2c: target eeprom extra api

drivers/i2c/target/eeprom_target.c

@@ -18,12 +18,15 @@
 LOG_MODULE_REGISTER(i2c_target);
 
 struct i2c_eeprom_target_data {
+	const struct device *dev;
 	struct i2c_target_config config;
 	uint32_t buffer_size;
 	uint8_t *buffer;
 	uint32_t buffer_idx;
 	uint32_t idx_write_cnt;
 	uint8_t address_width;
+	eeprom_target_changed_handler_t changed_handler;
+	bool changed;
 };
 
 struct i2c_eeprom_target_config {
@@ -32,6 +35,28 @@ struct i2c_eeprom_target_config {
 	uint8_t *buffer;
 };
 
+void eeprom_target_set_changed_callback(const struct device *dev,
+					eeprom_target_changed_handler_t handler)
+{
+	struct i2c_eeprom_target_data *data = dev->data;
+
+	data->changed_handler = handler;
+}
+
+unsigned int eeprom_target_get_size(const struct device *dev)
+{
+	struct i2c_eeprom_target_data *data = dev->data;
+
+	return data->buffer_size;
+}
+
+uint8_t *eeprom_target_get_data(const struct device *dev)
+{
+	struct i2c_eeprom_target_data *data = dev->data;
+
+	return data->buffer;
+}
+
 int eeprom_target_program(const struct device *dev, const uint8_t *eeprom_data,
 			 unsigned int length)
 {
@@ -131,6 +156,7 @@ static int eeprom_target_write_received(struct i2c_target_config *config,
 		data->idx_write_cnt++;
 	} else {
 		data->buffer[data->buffer_idx++] = val;
+		data->changed = true;
 	}
 
 	data->buffer_idx = data->buffer_idx % data->buffer_size;
@@ -169,6 +195,11 @@ static int eeprom_target_stop(struct i2c_target_config *config)
 
 	data->idx_write_cnt = 0;
 
+	if (data->changed && data->changed_handler) {
+		data->changed_handler(data->dev);
+	}
+	data->changed = false;
+
 	return 0;
 }
 
@@ -191,6 +222,7 @@ static void eeprom_target_buf_write_received(struct i2c_target_config *config,
 
 	if (len > 0) {
 		memcpy(&data->buffer[data->buffer_idx], ptr, len);
+		data->changed = true;
 	}
 }
 
@@ -251,6 +283,7 @@ static int i2c_eeprom_target_init(const struct device *dev)
 		return -ENODEV;
 	}
 
+	data->dev = dev;
 	data->buffer_size = cfg->buffer_size;
 	data->buffer = cfg->buffer;
 	data->config.address = cfg->bus.addr;

include/zephyr/drivers/i2c/target/eeprom.h

@@ -21,6 +21,41 @@
  * @{
  */
 
+/**
+ * @typedef eeprom_target_changed_handler_t
+ * @brief Define the application callback handler function signature
+ *
+ * @param dev Pointer to the device structure for the driver instance.
+ */
+typedef void (*eeprom_target_changed_handler_t)(const struct device *dev);
+
+/**
+ * @brief Set the EEPROM changed callback handler
+ *
+ * @param dev Pointer to the device structure for the driver instance.
+ * @param handler Handler to call on EEPROM changes
+ */
+void eeprom_target_set_changed_callback(const struct device *dev,
+					eeprom_target_changed_handler_t handler);
+
+/**
+ * @brief Get size of the virtual EEPROM
+ *
+ * @param dev Pointer to the device structure for the driver instance.
+ *
+ * @retval Size of EEPROM in bytes
+ */
+unsigned int eeprom_target_get_size(const struct device *dev);
+
+/**
+ * @brief Get a pointer to the data of the virtual EEPROM
+ *
+ * @param dev Pointer to the device structure for the driver instance.
+ *
+ * @retval Pointer to EEPROM data
+ */
+uint8_t *eeprom_target_get_data(const struct device *dev);
+
 /**
  * @brief Program memory of the virtual EEPROM
  *

samples/drivers/i2c/target_eeprom/src/main.c

@@ -11,6 +11,23 @@
 
 static const struct device *eeprom = DEVICE_DT_GET(DT_NODELABEL(eeprom0));
 
+static void on_changed(const struct device *dev)
+{
+	unsigned int size, i;
+	uint8_t *data;
+
+	size = eeprom_target_get_size(dev);
+	data = eeprom_target_get_data(dev);
+
+	printk("Eeprom changed, now contains:\n");
+	for (i = 0; i < size; i++) {
+		char sep = i % 16 == 15 ? '\n' : ' ';
+
+		printk("%02x%c", data[i], sep);
+	}
+	printk("\n");
+}
+
 int main(void)
 {
 	printk("i2c target sample\n");
@@ -20,21 +37,14 @@ int main(void)
 		return 0;
 	}
 
+	eeprom_target_set_changed_callback(eeprom, on_changed);
+
 	if (i2c_target_driver_register(eeprom) < 0) {
 		printk("Failed to register i2c target driver\n");
 		return 0;
 	}
 
 	printk("i2c target driver registered\n");
 
-	k_msleep(1000);
-
-	if (i2c_target_driver_unregister(eeprom) < 0) {
-		printk("Failed to unregister i2c target driver\n");
-		return 0;
-	}
-
-	printk("i2c target driver unregistered\n");
-
 	return 0;
 }