drivers: stepper: a4988

drivers/stepper/CMakeLists.txt

@@ -7,7 +7,8 @@
 add_subdirectory_ifdef(CONFIG_STEPPER_ADI_TMC adi_tmc)
 add_subdirectory_ifdef(CONFIG_STEPPER_TI ti)
 add_subdirectory_ifdef(CONFIG_STEP_DIR_STEPPER step_dir)
+add_subdirectory_ifdef(CONFIG_STEPPER_ALLEGRO allegro)
 # zephyr-keep-sorted-stop
 
 zephyr_library()
 zephyr_library_property(ALLOW_EMPTY TRUE)

drivers/stepper/Kconfig

@@ -35,6 +35,7 @@
 rsource "Kconfig.gpio"
 rsource "adi_tmc/Kconfig"
 rsource "ti/Kconfig"
+rsource "allegro/Kconfig"
 # zephyr-keep-sorted-stop
 
 endif

drivers/stepper/allegro/CMakeLists.txt

@@ -0,0 +1,7 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025 Marvin Ouma
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+zephyr_library_property(ALLOW_EMPTY TRUE)
+
+zephyr_library_sources_ifdef(CONFIG_A4988 a4988.c)

drivers/stepper/allegro/Kconfig

@@ -0,0 +1,8 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025 Marvin Ouma
+# SPDX-License-Identifier: Apache-2.0
+
+config STEPPER_ALLEGRO
+	bool
+	depends on STEPPER
+
+rsource "Kconfig.a4988"

drivers/stepper/allegro/Kconfig.a4988

@@ -0,0 +1,12 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025 Marvin Ouma
+# SPDX-License-Identifier: Apache-2.0
+
+config A4988
+       bool "A4988 DMOS Microstepping Driver"
+       default y
+       depends on DT_HAS_ALLEGRO_A4988_ENABLED
+       select STEPPER_ALLEGRO
+       select STEP_DIR_STEPPER
+       select STEPPER_STEP_DIR_GENERATE_ISR_SAFE_EVENTS
+       help
+        Enable A4988 DMOS Microstepping Driver.

drivers/stepper/allegro/a4988.c

@@ -0,0 +1,220 @@
+/*
+ * SPDX-FileCopyrightText: Copyright (c) 2025 Marvin Ouma
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT allegro_a4988
+
+#include <zephyr/device.h>
+#include <zephyr/devicetree.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/drivers/stepper.h>
+#include "../step_dir/step_dir_stepper_common.h"
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(a4988, CONFIG_STEPPER_LOG_LEVEL);
+
+#define MSX_PIN_COUNT       3
+#define MSX_PIN_STATE_COUNT 5
+
+static enum stepper_micro_step_resolution a4988_msx_resolutions[MSX_PIN_STATE_COUNT] = {
+	STEPPER_MICRO_STEP_1, STEPPER_MICRO_STEP_2,  STEPPER_MICRO_STEP_4,
+	STEPPER_MICRO_STEP_8, STEPPER_MICRO_STEP_16,
+};
+
+struct a4988_config {
+	struct step_dir_stepper_common_config common;
+	struct gpio_dt_spec sleep_pin;
+	struct gpio_dt_spec enable_pin;
+	struct gpio_dt_spec reset;
+	struct gpio_dt_spec *msx_pins;
+	enum stepper_micro_step_resolution *msx_resolutions;
+};
+
+struct a4988_data {
+	struct step_dir_stepper_common_data common;
+	enum stepper_micro_step_resolution resolution;
+};
+
+STEP_DIR_STEPPER_STRUCT_CHECK(struct a4988_config, struct a4988_data);
+
+static int a4988_stepper_enable(const struct device *dev, const bool enable)
+{
+	/* enable and sleep pins need to be set logic low to be on  */
+	const struct a4988_config *config = dev->config;
+	int ret;
+
+	if (config->sleep_pin.port != NULL) {
+		ret = gpio_pin_set_dt(&config->sleep_pin, enable);
+		if (ret < 0) {
+			LOG_WRN("Failed to set sleep pin %d", ret);
+		}
+	}
+
+	LOG_DBG("Stepper motor controller %s %s", dev->name, enable ? "enabled" : "disabled");
+	return gpio_pin_set_dt(&config->enable_pin, !enable);
+}
+
+/* Set microstepping mode
+ *
+ */
+static int a4988_stepper_set_micro_step_res(const struct device *dev,
+					    enum stepper_micro_step_resolution micro_step_res)
+{
+	struct a4988_data *data = dev->data;
+	const struct a4988_config *config = dev->config;
+	int ret;
+
+	if (!config->msx_pins) {
+		LOG_ERR("Microstep resolution pins are not configured");
+		return 0; // NOT CONNECTED
+	}
+
+	for (uint8_t i = 0; i < MSX_PIN_STATE_COUNT; ++i) {
+		if (micro_step_res != config->msx_resolutions[i]) {
+			continue;
+		}
+
+		ret = gpio_pin_set_dt(&config->msx_pins[0], i & 0x01);
+		if (ret < 0) {
+			LOG_ERR("Failed to set MS1 pin: %d", ret);
+			return ret;
+		}
+
+		ret = gpio_pin_set_dt(&config->msx_pins[1], (i & 0x02) >> 1);
+		if (ret < 0) {
+			LOG_ERR("Failed to set MS2 pin: %d", ret);
+			return ret;
+		}
+
+		ret = gpio_pin_set_dt(&config->msx_pins[2], (i & 0x04) >> 1);
+		if (ret < 0) {
+			LOG_ERR("Failed to set MS3 pin: %d", ret);
+			return ret;
+		}
+
+		data->resolution = micro_step_res;
+		return 0;
+	}
+
+	LOG_ERR("Unsupported microstep resolution: %d", micro_step_res);
+	return -EINVAL;
+}
+
+static int a4988_stepper_configure_msx_pins(const struct device *dev)
+{
+	const struct a4988_config *config = dev->config;
+	int ret;
+
+	for (uint8_t i = 0; i < MSX_PIN_COUNT; i++) {
+		if (!gpio_is_ready_dt(&config->msx_pins[i])) {
+			LOG_ERR("MSX pin %u is not ready", i);
+			return -ENODEV;
+		}
+
+		ret = gpio_pin_configure_dt(&config->msx_pins[i], GPIO_OUTPUT);
+		if (ret < 0) {
+			LOG_ERR("Failed to configure msx pin %u", i);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+static int a4988_stepper_get_micro_step_res(const struct device *dev,
+					    enum stepper_micro_step_resolution *micro_step_res)
+{
+
+	struct a4988_data *data = dev->data;
+	*micro_step_res = data->resolution;
+	return 0;
+}
+
+static int a4988_stepper_init(const struct device *dev)
+{
+	const struct a4988_config *config = dev->config;
+	const struct a4988_data *data = dev->data;
+	int ret;
+
+	if (config->sleep_pin.port != NULL) {
+		ret = gpio_pin_configure_dt(&config->sleep_pin, GPIO_OUTPUT_ACTIVE);
+		if (ret < 0) {
+			LOG_ERR("Failed to configure sleep pin: %d", ret);
+			return -ENODEV;
+		}
+	}
+
+	if (!gpio_is_ready_dt(&config->enable_pin)) {
+		LOG_ERR("GPIO pins are not ready");
+		return -ENODEV;
+	}
+
+	ret = gpio_pin_configure_dt(&config->enable_pin, GPIO_OUTPUT);
+	if (ret < 0) {
+		LOG_ERR("Failed to configure enable pin: %d", ret);
+		return ret;
+	}
+
+	if (config->msx_pins) {
+		ret = a4988_stepper_configure_msx_pins(dev);
+		if (ret < 0) {
+			LOG_ERR("Failed to configure MSX pins: %d", ret);
+			return ret;
+		}
+
+		ret = a4988_stepper_set_micro_step_res(dev, data->resolution);
+		if (ret < 0) {
+			LOG_ERR("Failed to set microstep resolution: %d", ret);
+			return ret;
+		}
+	}
+
+	ret = step_dir_stepper_common_init(dev);
+	if (ret < 0) {
+		LOG_ERR("Failed to init step dir common stepper: %d", ret);
+		return ret;
+	}
+	return 0;
+}
+
+static DEVICE_API(stepper, a4988_stepper_api) = {
+	.enable = a4988_stepper_enable,
+	.move_by = step_dir_stepper_common_move_by,
+	.is_moving = step_dir_stepper_common_is_moving,
+	.set_reference_position = step_dir_stepper_common_set_reference_position,
+	.get_actual_position = step_dir_stepper_common_get_actual_position,
+	.move_to = step_dir_stepper_common_move_to,
+	.set_microstep_interval = step_dir_stepper_common_set_microstep_interval,
+	.run = step_dir_stepper_common_run,
+	.set_event_callback = step_dir_stepper_common_set_event_callback,
+	.set_micro_step_res = a4988_stepper_set_micro_step_res,
+	.get_micro_step_res = a4988_stepper_get_micro_step_res,
+};
+
+#define A4988_STEPPER_DEFINE(inst, msx_table)                                                        \
+	IF_ENABLED(DT_INST_NODE_HAS_PROP(inst, msx_gpios), (                                       \
+	static const struct gpio_dt_spec a4988_stepper_msx_pins_##inst[] = {                     \
+		DT_INST_FOREACH_PROP_ELEM_SEP(                                                     \
+			inst, msx_gpios, GPIO_DT_SPEC_GET_BY_IDX, (,)                              \
+		),                                                                                 \
+	};                                                                                         \
+	BUILD_ASSERT(                                                                              \
+		ARRAY_SIZE(a4988_stepper_msx_pins_##inst) == MSX_PIN_COUNT,                      \
+		"Three microstep config pins needed");                                               \
+	)) \
+                                                                                                     \
+	static const struct a4988_config a4988_config_##inst = {                                     \
+		.common = STEP_DIR_STEPPER_DT_INST_COMMON_CONFIG_INIT(inst),                         \
+		.enable_pin = GPIO_DT_SPEC_INST_GET(inst, en_gpios),                                 \
+		.msx_resolutions = msx_table,                                                        \
+		IF_ENABLED(DT_INST_NODE_HAS_PROP(inst, msx_gpios),				   \
+			   (.msx_pins = (struct gpio_dt_spec *)a4988_stepper_msx_pins_##inst)) };         \
+	static struct a4988_data a4988_data_##inst = {                                               \
+		.common = STEP_DIR_STEPPER_DT_INST_COMMON_DATA_INIT(inst),                           \
+		.resolution = DT_INST_PROP(inst, micro_step_res),                                    \
+	};                                                                                           \
+	DEVICE_DT_INST_DEFINE(inst, a4988_stepper_init, NULL, &a4988_data_##inst,                    \
+			      &a4988_config_##inst, POST_KERNEL, CONFIG_STEPPER_INIT_PRIORITY,       \
+			      &a4988_stepper_api);
+
+DT_INST_FOREACH_STATUS_OKAY_VARGS(A4988_STEPPER_DEFINE, a4988_msx_resolutions)

dts/bindings/stepper/allegro/allegro,a4988.yaml

@@ -0,0 +1,47 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025 Marvin Ouma
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  Allegro A4988 stepper motor driver.
+
+  Example:
+  a4988: a4988 {
+    status = "okay";
+    compatible = "allegro,a4988";
+
+    step-gpios = <&gpio0 15 GPIO_ACTIVE_HIGH>;
+    dir-gpios = <&gpio0 2 GPIO_ACTIVE_HIGH>;
+    en-gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>;
+    msx-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>,
+                <&gpio0 17 GPIO_ACTIVE_HIGH>,
+                <&gpio0 5 GPIO_ACTIVE_HIGH>;
+  };
+
+compatible: "allegro,a4988"
+
+include:
+  - name: stepper-controller.yaml
+    property-allowlist:
+      - micro-step-res
+      - step-gpios
+      - dir-gpios
+      - en-gpios
+
+
+properties:
+  msx-gpios:
+    type: phandle-array
+    description: |
+      An array of GPIO pins for configuring the microstep resolution of the driver.
+      The pins should be listed in the following order:
+        - MS1
+        - MS2
+        - MS3
+
+  sleep-gpios:
+    type: phandle-array
+    description: Sleep pin
+
+  reset-gpios:
+    type: phandle-array
+    description: Reset pin

samples/drivers/stepper/a4988/CMakeLists.txt

@@ -0,0 +1,10 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025 Marvin Ouma
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(a4988)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})

samples/drivers/stepper/a4988/Kconfig

@@ -0,0 +1,11 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025 Marvin Ouma
+# SPDX-License-Identifier: Apache-2.0
+
+mainmenu "A4988 sample application"
+
+config STEPS_PER_REV
+       int "Steps per revolution"
+       default 200
+
+
+source "Kconfig.zephyr"

samples/drivers/stepper/a4988/README.rst

@@ -0,0 +1,23 @@
+.. zephyr:code-sample:: stepper/a4988
+   :name: A4988 Stepper Driver
+   :relevant-api: stepper_interface
+
+   Rotate a A4988 stepper motor.
+
+Overview
+********
+
+This sample applications rotates the A4988 stepper motor at a constant speed.
+
+
+Building and Running
+********************
+
+The sample applications spins the stepper and outputs the events to the console. It requires
+an A4988 stepper driver. It should work with any platform with enough gpios to spare.
+It does not work on QEMU.
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/drivers/stepper/a4988
+   :board: stm32_min_dev
+   :goals: build flash

samples/drivers/stepper/a4988/boards/stm32_min_dev.overlay

@@ -0,0 +1,32 @@
+/ {
+
+	chosen {
+	       zephyr,console=&cdc_acm_uart0;
+	};
+
+	aliases {
+		stepper = &a4988;
+	};
+
+	a4988: a4988 {
+		compatible = "allegro,a4988";
+		status = "okay";
+
+		step-gpios = <&gpiob 45 GPIO_ACTIVE_HIGH>;
+		dir-gpios = <&gpiob 46 GPIO_ACTIVE_HIGH>;
+		en-gpios = <&gpioa 38 GPIO_ACTIVE_LOW>;
+		sleep-gpios = <&gpiob 43 GPIO_ACTIVE_LOW>;
+		reset-gpios = <&gpiob 42 GPIO_ACTIVE_HIGH>;
+		msx-gpios = <&gpiob 39 GPIO_ACTIVE_HIGH>,
+		            <&gpiob 40 GPIO_ACTIVE_HIGH>,
+		            <&gpiob 41 GPIO_ACTIVE_HIGH>;
+		micro-step-res = <16>;
+	};
+};
+
+&zephyr_udc0 {
+	     cdc_acm_uart0: cdc_acm_uart0 {
+	     	compatible = "zephyr,cdc-acm-uart";
+		label = "CDC_ACM_0";
+	     };
+};