Add latch functionality for stepper motor control

drivers/stepper/gpio_stepper_controller.c

@@ -39,6 +39,7 @@
 	uint32_t delay_in_us;
 	int32_t step_count;
 	void *event_cb_user_data;
+	bool latch;
 };
 
 static int stepper_motor_set_coil_charge(const struct device *dev)
@@ -108,6 +109,11 @@
 		update_coil_charge(dev);
 	}
 	update_remaining_steps(dev->data);
+	if (data -> step_count == 0 && !data->latch) {
+		for (uint8_t n_pin = 0; n_pin < NUM_CONTROL_PINS; n_pin++) {
+			(void)gpio_pin_set_dt(&config->control_pins[n_pin], 0);
+		}
+	}
 }
 
 static void velocity_mode_task(const struct device *dev)
@@ -125,8 +131,8 @@
 	struct gpio_stepper_data *data =
 		CONTAINER_OF(dwork, struct gpio_stepper_data, stepper_dwork);
 
 	K_SPINLOCK(&data->lock) {
 		switch (data->run_mode) {
 		case STEPPER_RUN_MODE_POSITION:
 			position_mode_task(data->dev);
 			break;
@@ -296,6 +302,20 @@
 	return 0;
 }
 
+static int gpio_stepper_set_latch(const struct device *dev, bool is_latch_after_movement)
+{
+	struct gpio_stepper_data *data = dev->data;
+	data->latch = is_latch_after_movement;
+	return 0;
+}
+
+static int gpio_stepper_is_latch(const struct device *dev, bool* latching_state)
+{
+	struct gpio_stepper_data *data = dev->data;
+	*latching_state = data->latch;
+	return 0;
+}
+
 static int gpio_stepper_motor_controller_init(const struct device *dev)
 {
 	struct gpio_stepper_data *data = dev->data;
@@ -307,12 +327,12 @@
 	for (uint8_t n_pin = 0; n_pin < NUM_CONTROL_PINS; n_pin++) {
 		(void)gpio_pin_configure_dt(&config->control_pins[n_pin], GPIO_OUTPUT_INACTIVE);
 	}
 	k_work_init_delayable(&data->stepper_dwork, stepper_work_step_handler);
 	return 0;
 }
 
 #define GPIO_STEPPER_DEVICE_DATA_DEFINE(child)                                                     \
 	static struct gpio_stepper_data gpio_stepper_data_##child = {                              \
 		.step_gap = MAX_MICRO_STEP_RES >> (DT_PROP(child, micro_step_res) - 1),            \
 	};                                                                                         \
 	BUILD_ASSERT(DT_PROP(child, micro_step_res) <= STEPPER_MICRO_STEP_2,                       \
@@ -340,6 +360,8 @@
 		.enable_constant_velocity_mode = gpio_stepper_enable_constant_velocity_mode,       \
 		.set_micro_step_res = gpio_stepper_set_micro_step_res,                             \
 		.get_micro_step_res = gpio_stepper_get_micro_step_res,                             \
+		.set_latch = gpio_stepper_set_latch,    										   \
+		.is_latch  = gpio_stepper_is_latch,												   \
 		.set_event_callback = gpio_stepper_set_event_callback, };
 
 #define GPIO_STEPPER_DEVICE_DEFINE(child)                                                          \

include/zephyr/drivers/stepper.h

@@ -184,7 +184,23 @@
 typedef int (*stepper_set_event_callback_t)(const struct device *dev,
 					    stepper_event_callback_t callback, void *user_data);
 
+/**
+ * @brief Set the stepper latch after movement.
+ * 
+ * @see stepper_set_latch() for details.
+ */
+typedef int (*stepper_set_latch_t)(const struct device *dev,
+					  const bool is_latch_after_movement);
+
+
+/**
+ * @brief Get the stepper latch state.
+ *
+ * @see stepper_is_latch() for details.
+ */
+typedef int (*stepper_is_latch_t)(const struct device *dev, bool* is_latch_after_movement);
+
 /**
  * @brief Stepper Motor Controller API
  */
 __subsystem struct stepper_driver_api {
@@ -199,6 +215,8 @@
 	stepper_is_moving_t is_moving;
 	stepper_enable_constant_velocity_mode_t enable_constant_velocity_mode;
 	stepper_set_event_callback_t set_event_callback;
+	stepper_set_latch_t set_latch;
+	stepper_is_latch_t is_latch;
 };
 
 /**
@@ -462,6 +480,36 @@
 	return api->set_event_callback(dev, callback, user_data);
 }
 
+/**
+ * @brief Set whether the stepper motor should latch after movement.
+ *
+ * @param dev Pointer to the device structure for the stepper motor.
+ * @param is_latch_after_movement Boolean indicating whether the motor should latch after movement.
+ * @retval -EIO General input / output error
+ * @retval	0 Success
+ */
+__syscall int stepper_set_latch(const struct device *dev, bool is_latch_after_movement);
+
+static inline int z_impl_stepper_set_latch(const struct device *dev, bool is_latch_after_movement) {
+    const struct stepper_driver_api *api = (const struct stepper_driver_api *)dev->api;
+    return api->set_latch(dev, is_latch_after_movement);
+}
+
+/**
+ * @brief Get the current latch configuration of the stepper motor.
+ *
+ * @param dev Pointer to the device structure for the stepper motor.
+ * @param latching_state Pointer to a boolean where the latch state will be stored.
+ * @retval -EIO General input / output error
+ * @retval	0 Success
+ */
+__syscall int stepper_is_latch(const struct device *dev, bool* latching_state);
+
+static inline int z_impl_stepper_is_latch(const struct device *dev, bool* latching_state) {
+    const struct stepper_driver_api *api = (const struct stepper_driver_api *)dev->api;
+    return api->is_latch(dev, latching_state);
+}
+
 /**
  * @}
  */