drivers: sensor: Add infineon xmc4xxx die temperature sensor

Adds die temperature driver for infineon xmc4xxx SoCs.

Signed-off-by: Andriy Gelman <andriy.gelman@gmail.com>

boards/arm/xmc45_relax_kit/xmc45_relax_kit.dts

@@ -19,6 +19,7 @@
 
 	aliases {
 		led0 = &led1;
+		die-temp0 = &die_temp;
 	};
 
 	leds {

drivers/sensor/CMakeLists.txt

@@ -119,6 +119,7 @@ add_subdirectory_ifdef(CONFIG_VCMP_IT8XXX2	ite_vcmp_it8xxx2)
 add_subdirectory_ifdef(CONFIG_PCNT_ESP32	pcnt_esp32)
 add_subdirectory_ifdef(CONFIG_ESP32_TEMP	esp32_temp)
 add_subdirectory_ifdef(CONFIG_RPI_PICO_TEMP	rpi_pico_temp)
+add_subdirectory_ifdef(CONFIG_XMC4XXX_TEMP	xmc4xxx_temp)
 
 if(CONFIG_USERSPACE OR CONFIG_SENSOR_SHELL OR CONFIG_SENSOR_SHELL_BATTERY)
 # The above if() is needed or else CMake would complain about

drivers/sensor/Kconfig

@@ -277,4 +277,6 @@ source "drivers/sensor/esp32_temp/Kconfig"
 
 source "drivers/sensor/rpi_pico_temp/Kconfig"
 
+source "drivers/sensor/xmc4xxx_temp/Kconfig"
+
 endif # SENSOR

drivers/sensor/xmc4xxx_temp/CMakeLists.txt

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+
+zephyr_library_sources(xmc4xxx_temp.c)

drivers/sensor/xmc4xxx_temp/Kconfig

@@ -0,0 +1,26 @@
+# Copyright (c) 2023 Andriy Gelman <andriy.gelman@gmail.com>
+# SPDX-License-Identifier: Apache-2.0
+
+config XMC4XXX_TEMP
+	bool "XMC4XXX Temperature Sensor"
+	default y
+	depends on DT_HAS_INFINEON_XMC4XXX_TEMP_ENABLED
+	help
+	  Enable driver for temperature sensor on Infineon XMC4XXX targets.
+
+if XMC4XXX_TEMP
+
+config XMC4XXX_TEMP_CALIBRATE_OFFSET
+	int "Offset adjumstment of the temperature reading"
+	default 0
+	help
+	  Offset adjustment is defined as a shift of the conversion result.
+	  The value is 7 bits in the range [-64, 63] which maps to -/+ 12.5C.
+
+config XMC4XXX_TEMP_CALIBRATE_GAIN
+	int "Gain adjumstment of the temperature reading"
+	default 32
+	help
+	  Gain adjustment of the temperature reading. Range [0, 63].
+
+endif # XMC4XXX_TEMP

drivers/sensor/xmc4xxx_temp/xmc4xxx_temp.c

@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2023 Andriy Gelman <andriy.gelman@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT infineon_xmc4xxx_temp
+
+#include <xmc_scu.h>
+
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/devicetree.h>
+#include <zephyr/drivers/sensor.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(xmc4xxx_temp, CONFIG_SENSOR_LOG_LEVEL);
+
+struct xmc4xxx_temp_data {
+	float temp_out;
+};
+
+static int xmc4xxx_temp_sample_fetch(const struct device *dev, enum sensor_channel chan)
+{
+	struct xmc4xxx_temp_data *data = dev->data;
+	int32_t val;
+	int ret;
+
+	if (chan != SENSOR_CHAN_ALL && chan != SENSOR_CHAN_DIE_TEMP) {
+		return -ENOTSUP;
+	}
+
+	ret = XMC_SCU_StartTemperatureMeasurement();
+	if (ret != 0) {
+		return -EBUSY;
+	}
+
+	while (XMC_SCU_IsTemperatureSensorBusy()) {
+	};
+
+	val = XMC_SCU_GetTemperatureMeasurement();
+	/* See Infineon XMC4500 Reference Manual Section 11.2.5.1 */
+	data->temp_out = (val - 605) / 2.05f;
+
+	return ret;
+}
+
+static int xmc4xxx_temp_channel_get(const struct device *dev, enum sensor_channel chan,
+				    struct sensor_value *val)
+{
+	struct xmc4xxx_temp_data *data = dev->data;
+
+	if (chan != SENSOR_CHAN_DIE_TEMP) {
+		return -ENOTSUP;
+	}
+
+	return sensor_value_from_double(val, data->temp_out);
+}
+
+static const struct sensor_driver_api xmc4xxx_temp_driver_api = {
+	.sample_fetch = xmc4xxx_temp_sample_fetch,
+	.channel_get = xmc4xxx_temp_channel_get,
+};
+
+static int xmc4xxx_temp_init(const struct device *dev)
+{
+	ARG_UNUSED(dev);
+	XMC_SCU_EnableTemperatureSensor();
+
+	BUILD_ASSERT(CONFIG_XMC4XXX_TEMP_CALIBRATE_OFFSET >= -64 &&
+		     CONFIG_XMC4XXX_TEMP_CALIBRATE_OFFSET <= 63);
+
+	BUILD_ASSERT(CONFIG_XMC4XXX_TEMP_CALIBRATE_GAIN >= 0 &&
+		     CONFIG_XMC4XXX_TEMP_CALIBRATE_OFFSET <= 63);
+
+	XMC_SCU_CalibrateTemperatureSensor(CONFIG_XMC4XXX_TEMP_CALIBRATE_OFFSET & 0x7f,
+					   CONFIG_XMC4XXX_TEMP_CALIBRATE_GAIN);
+	return 0;
+}
+
+#define XMC4XXX_TEMP_DEFINE(inst)								\
+	static struct xmc4xxx_temp_data xmc4xxx_temp_dev_data_##inst;				\
+												\
+	SENSOR_DEVICE_DT_INST_DEFINE(inst, xmc4xxx_temp_init, NULL,				\
+			      &xmc4xxx_temp_dev_data_##inst, NULL,				\
+			      POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY,				\
+			      &xmc4xxx_temp_driver_api);					\
+
+DT_INST_FOREACH_STATUS_OKAY(XMC4XXX_TEMP_DEFINE)

dts/arm/infineon/xmc4xxx.dtsi

@@ -159,6 +159,12 @@
 			#io-channel-cells = <1>;
 			status = "disabled";
 		};
+
+		die_temp: die_temp@5000408c {
+			reg = <0x5000408c 0x8>;
+			compatible = "infineon,xmc4xxx-temp";
+			status = "disabled";
+		};
 	};
 };
 

dts/bindings/sensor/infineon,xmc4xxx-temp.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2023 Andriy Gelman <andriy.gelman@gmail.com>
+# SPDX-License-Identifier: Apache-2.0
+
+description: Infineon XMC4XXX die temperature sensor
+
+compatible: "infineon,xmc4xxx-temp"
+
+include: sensor-device.yaml