sensors: as5048: add initial support for AS5048 angle sensor

drivers/sensor/ams/CMakeLists.txt

@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 # zephyr-keep-sorted-start
+add_subdirectory_ifdef(CONFIG_AMS_AS5048 ams_as5048)
 add_subdirectory_ifdef(CONFIG_AMS_AS5600 ams_as5600)
 add_subdirectory_ifdef(CONFIG_AMS_IAQ_CORE ams_iAQcore)
 add_subdirectory_ifdef(CONFIG_CCS811 ccs811)

drivers/sensor/ams/Kconfig

@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 # zephyr-keep-sorted-start
+source "drivers/sensor/ams/ams_as5048/Kconfig"
 source "drivers/sensor/ams/ams_as5600/Kconfig"
 source "drivers/sensor/ams/ams_iAQcore/Kconfig"
 source "drivers/sensor/ams/ccs811/Kconfig"

drivers/sensor/ams/ams_as5048/CMakeLists.txt

@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+zephyr_library_sources(ams_as5048.c)

drivers/sensor/ams/ams_as5048/Kconfig

@@ -0,0 +1,13 @@
+# AS5048 Angular position sensor configuration option
+
+# Copyright (c) 2025, Felipe Neves.
+# SPDX-License-Identifier: Apache-2.0
+
+config AMS_AS5048
+	bool "AMS AS5048 magnetic angle sensor"
+	default y
+	depends on DT_HAS_AMS_AS5048_ENABLED
+	select SPI
+	help
+	  Enable driver for the AMS AS5048 magnetic rotary encoder. The driver
+	  supports reading the absolute angle via the SPI interface.

drivers/sensor/ams/ams_as5048/ams_as5048.c

@@ -0,0 +1,161 @@
+/*
+ * Copyright (c) 2025, Felipe Neves
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT ams_as5048
+
+#include <errno.h>
+#include <zephyr/device.h>
+#include <zephyr/drivers/sensor.h>
+#include <zephyr/drivers/spi.h>
+#include <zephyr/init.h>
+#include <zephyr/logging/log.h>
+#include <zephyr/sys/byteorder.h>
+
+LOG_MODULE_REGISTER(ams_as5048, CONFIG_SENSOR_LOG_LEVEL);
+
+#define AS5048_REG_ANGLE        0x3FFF
+#define AS5048_READ_BIT         BIT(14)
+#define AS5048_PARITY_BIT       BIT(15)
+#define AS5048_DATA_MASK        GENMASK(13, 0)
+#define AS5048_ERROR_BIT        BIT(14)
+#define AS5048_MAX_STEPS        16384
+#define AS5048_FULL_ANGLE_DEG   360
+#define AS5048_MICRO_DEGREE     1000000
+
+struct as5048_config {
+	struct spi_dt_spec spi;
+};
+
+struct as5048_data {
+	uint16_t angle_raw;
+};
+
+static uint16_t as5048_build_read_command(uint16_t reg)
+{
+	uint16_t cmd = reg & AS5048_DATA_MASK;
+
+	cmd |= AS5048_READ_BIT;
+
+	/* Even parity across bits 0..14 (read bit + address). */
+	if (__builtin_parity(cmd)) {
+		cmd |= AS5048_PARITY_BIT;
+	}
+
+	return cmd;
+}
+
+static int as5048_sample_fetch(const struct device *dev, enum sensor_channel chan)
+{
+	struct as5048_data *data = dev->data;
+	const struct as5048_config *cfg = dev->config;
+	uint16_t tx_buf[2];
+	uint16_t rx_buf[2];
+	struct spi_buf tx[] = {
+		{
+			.buf = &tx_buf[0],
+			.len = sizeof(tx_buf[0]),
+		},
+		{
+			.buf = &tx_buf[1],
+			.len = sizeof(tx_buf[1]),
+		},
+	};
+
+	const struct spi_buf_set tx_set = {
+		.buffers = tx,
+		.count = ARRAY_SIZE(tx),
+	};
+
+	struct spi_buf rx[] = {
+		{
+			.buf = &rx_buf[0],
+			.len = sizeof(rx_buf[0]),
+		},
+		{
+			.buf = &rx_buf[1],
+			.len = sizeof(rx_buf[1]),
+		},
+	};
+
+	const struct spi_buf_set rx_set = {
+		.buffers = rx,
+		.count = ARRAY_SIZE(rx),
+	};
+
+	int ret;
+
+	if ((chan != SENSOR_CHAN_ALL) && (chan != SENSOR_CHAN_ROTATION)) {
+		return -ENOTSUP;
+	}
+
+	tx_buf[0] = sys_cpu_to_be16(as5048_build_read_command(AS5048_REG_ANGLE));
+	tx_buf[1] = sys_cpu_to_be16(0x0000);
+
+	ret = spi_transceive_dt(&cfg->spi, &tx_set, &rx_set);
+	if (ret < 0) {
+		LOG_ERR("spi transceive failed (%d)", ret);
+		return ret;
+	}
+
+	uint16_t raw = sys_be16_to_cpu(rx_buf[1]);
+
+	if (raw & AS5048_ERROR_BIT) {
+		LOG_ERR("AS5048 reported error (0x%04x)", raw);
+		return -EIO;
+	}
+
+	data->angle_raw = raw & AS5048_DATA_MASK;
+
+	return 0;
+}
+
+static int as5048_channel_get(const struct device *dev,
+				 enum sensor_channel chan,
+				 struct sensor_value *val)
+{
+	struct as5048_data *data = dev->data;
+
+	if (chan != SENSOR_CHAN_ROTATION) {
+		return -ENOTSUP;
+	}
+
+	int32_t scaled = (int32_t)data->angle_raw * AS5048_FULL_ANGLE_DEG;
+
+	val->val1 = scaled / AS5048_MAX_STEPS;
+	val->val2 = ((scaled % AS5048_MAX_STEPS) * AS5048_MICRO_DEGREE) / AS5048_MAX_STEPS;
+
+	return 0;
+}
+
+static int as5048_init(const struct device *dev)
+{
+	const struct as5048_config *cfg = dev->config;
+
+	if (!spi_is_ready_dt(&cfg->spi)) {
+		LOG_ERR("SPI device not ready");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static DEVICE_API(sensor, as5048_api) = {
+	.sample_fetch = as5048_sample_fetch,
+	.channel_get = as5048_channel_get,
+};
+
+#define AS5048_INIT(inst) \
+	static struct as5048_data as5048_data_##inst; \
+	static const struct as5048_config as5048_config_##inst = { \
+		.spi = SPI_DT_SPEC_INST_GET(inst, \
+				SPI_WORD_SET(16) | SPI_TRANSFER_MSB), \
+	}; \
+	SENSOR_DEVICE_DT_INST_DEFINE(inst, as5048_init, NULL, \
+				 &as5048_data_##inst, &as5048_config_##inst, \
+				 POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY, \
+				 &as5048_api);
+
+DT_INST_FOREACH_STATUS_OKAY(AS5048_INIT)

dts/bindings/sensor/ams,as5048.yaml

@@ -0,0 +1,26 @@
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  AMS AS5048 magnetic rotary sensor
+
+    &spi3 {
+    status = "okay";
+
+    as5048@0 {
+      compatible = "ams,as5048";
+      reg = <0>;
+      spi-max-frequency = <4000000>;
+    };
+  };
+
+
+compatible: "ams,as5048"
+
+include: [sensor-device.yaml, spi-device.yaml]
+
+properties:
+  reg:
+    required: true
+
+  spi-max-frequency:
+    required: true

tests/drivers/build_all/sensor/app.overlay

@@ -156,7 +156,8 @@
 				   <&test_gpio 0 0>,
 				   <&test_gpio 0 0>,
 				   <&test_gpio 0 0>,
-				   <&test_gpio 0 0>;	/* 0x39 */
+				   <&test_gpio 0 0>,
+				   <&test_gpio 0 0>;	/* 0x3A */
 			#include "spi.dtsi"
 		};
 

tests/drivers/build_all/sensor/spi.dtsi

@@ -489,3 +489,9 @@ test_spi_adxl345: adxl345@3a {
 	int1-gpios = <&test_gpio 0 0>;
 	fifo-watermark = <1>;
 };
+
+test_spi_as5048: as5048@3b {
+	compatible = "ams,as5048";
+	reg = <0x3b>;
+	spi-max-frequency = <0>;
+};