drivers: sensors: sm351lt: Add new driver

Adds sm351lt magnetoresitive sensor driver.

Signed-off-by: Jamie McCrae <jamie.mccrae@lairdconnect.com>

boards/arm/bt510/bt510.dts

@@ -69,8 +69,9 @@
 	mag {
 		compatible = "gpio-keys";
 		mag0: mag_0 {
+			compatible = "honeywell,sm351lt";
 			gpios = <&gpio1 14 0>;
-			label = "Magnetoresitive Sensor";
+			label = "SM351LT_0";
 		};
 	};
 

boards/arm/bt510/bt510.yaml

@@ -13,3 +13,4 @@ supported:
   - pwm
   - watchdog
   - i2c
+  - sm351lt

boards/arm/bt510/bt510_defconfig

@@ -24,6 +24,9 @@ CONFIG_LIS2DH_TRIGGER_GLOBAL_THREAD=y
 CONFIG_LIS2DH_OPER_MODE_LOW_POWER=y
 CONFIG_SI7055=y
 
+# enable magnetoresistive driver
+CONFIG_SM351LT=y
+
 # enable console
 CONFIG_CONSOLE=y
 CONFIG_UART_CONSOLE=y

drivers/sensor/CMakeLists.txt

@@ -63,6 +63,7 @@ add_subdirectory_ifdef(CONFIG_SHT3XD		sht3xd)
 add_subdirectory_ifdef(CONFIG_SI7006		si7006)
 add_subdirectory_ifdef(CONFIG_SI7055		si7055)
 add_subdirectory_ifdef(CONFIG_SI7060		si7060)
+add_subdirectory_ifdef(CONFIG_SM351LT		sm351lt)
 add_subdirectory_ifdef(CONFIG_STTS751		stts751)
 add_subdirectory_ifdef(CONFIG_SX9500		sx9500)
 add_subdirectory_ifdef(CONFIG_TH02		    th02)

drivers/sensor/Kconfig

@@ -165,6 +165,8 @@ source "drivers/sensor/si7055/Kconfig"
 
 source "drivers/sensor/si7060/Kconfig"
 
+source "drivers/sensor/sm351lt/Kconfig"
+
 source "drivers/sensor/stts751/Kconfig"
 
 source "drivers/sensor/sx9500/Kconfig"

drivers/sensor/sm351lt/CMakeLists.txt

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+
+zephyr_library_sources_ifdef(CONFIG_SM351LT sm351lt.c)

drivers/sensor/sm351lt/Kconfig

@@ -0,0 +1,50 @@
+# SM351LT Magnetoresitive Sensor configuration options
+
+# Copyright (c) 2020, Laird Connectivity
+# SPDX-License-Identifier: Apache-2.0
+
+menuconfig SM351LT
+	bool "SM351LT Magnetoresistive Sensor"
+	depends on (GPIO)
+	help
+	  Enable GPIO-based driver for SM351LT magnetoresistive
+	  sensor.
+
+if SM351LT
+
+choice SM351LT_TRIGGER_MODE
+	prompt "Trigger mode"
+	help
+	  Specify the type of triggering to be used by the driver.
+
+config SM351LT_TRIGGER_NONE
+	bool "No trigger"
+
+config SM351LT_TRIGGER_GLOBAL_THREAD
+	bool "Use global thread"
+	select SM351LT_TRIGGER
+
+config SM351LT_TRIGGER_OWN_THREAD
+	bool "Use own thread"
+	select SM351LT_TRIGGER
+
+endchoice
+
+config SM351LT_TRIGGER
+	bool
+
+config SM351LT_THREAD_PRIORITY
+	int "Thread priority"
+	depends on SM351LT_TRIGGER_OWN_THREAD
+	default 10
+	help
+	  Priority of thread used by the driver to handle interrupts.
+
+config SM351LT_THREAD_STACK_SIZE
+	int "Thread stack size"
+	depends on SM351LT_TRIGGER_OWN_THREAD
+	default 512
+	help
+	  Stack size of thread used by the driver to handle interrupts.
+
+endif # SM351LT

drivers/sensor/sm351lt/sm351lt.c

@@ -0,0 +1,268 @@
+/*
+ * Copyright (c) 2020, Laird Connectivity
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT honeywell_sm351lt
+
+#include "sm351lt.h"
+
+#include <init.h>
+#include <sys/byteorder.h>
+#include <logging/log.h>
+#include <stdio.h>
+#include <sys/util.h>
+#include <drivers/gpio.h>
+#include <drivers/sensor.h>
+#include <string.h>
+
+LOG_MODULE_REGISTER(SM351LT, CONFIG_SENSOR_LOG_LEVEL);
+
+#if CONFIG_SM351LT_TRIGGER
+static int sm351lt_trigger_set(struct device *dev,
+			       const struct sensor_trigger *trig,
+			       sensor_trigger_handler_t handler)
+{
+	const struct sm351lt_config *const config = dev->config;
+	struct sm351lt_data *data = dev->data;
+	int ret = -ENOTSUP;
+
+	if (trig->chan == SENSOR_CHAN_PROX) {
+		data->changed_handler = handler;
+		ret = gpio_pin_interrupt_configure(data->bus, config->gpio_pin,
+						   (handler ? data->trigger_type
+							    : GPIO_INT_DISABLE));
+
+		if (ret < 0) {
+			return ret;
+		}
+
+		if (handler) {
+			ret = gpio_add_callback(data->bus, &data->gpio_cb);
+		} else {
+			ret = gpio_remove_callback(data->bus, &data->gpio_cb);
+		}
+	}
+
+	return ret;
+}
+
+static void sm351lt_gpio_callback(struct device *dev,
+				  struct gpio_callback *cb, uint32_t pins)
+{
+	struct sm351lt_data *data =
+		CONTAINER_OF(cb, struct sm351lt_data, gpio_cb);
+
+#if defined(CONFIG_SM351LT_TRIGGER_OWN_THREAD)
+	k_sem_give(&data->gpio_sem);
+#elif defined(CONFIG_SM351LT_TRIGGER_GLOBAL_THREAD)
+	k_work_submit(&data->work);
+#endif
+}
+
+static void sm351lt_thread_cb(void *arg)
+{
+	struct device *dev = arg;
+	struct sm351lt_data *data = dev->data;
+
+	struct sensor_trigger mag_trigger = {
+		.type = SENSOR_TRIG_NEAR_FAR,
+		.chan = SENSOR_CHAN_PROX,
+	};
+
+	if (likely(data->changed_handler != NULL)) {
+		data->changed_handler(dev, &mag_trigger);
+	}
+
+	return;
+}
+
+#if defined(CONFIG_SM351LT_TRIGGER_OWN_THREAD)
+static void sm351lt_thread(void *arg1, void *unused2, void *unused3)
+{
+	struct device *dev = arg1;
+	struct sm351lt_data *data = dev->data;
+
+	ARG_UNUSED(unused2);
+	ARG_UNUSED(unused3);
+
+	while (1) {
+		k_sem_take(&data->gpio_sem, K_FOREVER);
+		sm351lt_thread_cb(dev);
+	}
+}
+#endif
+
+#if defined(CONFIG_SM351LT_TRIGGER_GLOBAL_THREAD)
+static void sm351lt_work_cb(struct k_work *work)
+{
+	struct sm351lt_data *data =
+		CONTAINER_OF(work, struct sm351lt_data, work);
+
+	sm351lt_thread_cb(data->dev);
+}
+#endif
+#endif
+
+static int sm351lt_sample_fetch(struct device *dev,
+				enum sensor_channel chan)
+{
+	const struct sm351lt_config *config = dev->config;
+	struct sm351lt_data *data = dev->data;
+
+	if (chan != SENSOR_CHAN_ALL && chan != SENSOR_CHAN_PROX) {
+		return -ENOTSUP;
+	}
+
+	data->sample_status = gpio_pin_get(data->bus, config->gpio_pin);
+
+	return 0;
+}
+
+static int sm351lt_channel_get(struct device *dev,
+			       enum sensor_channel chan,
+			       struct sensor_value *val)
+{
+	struct sm351lt_data *data = dev->data;
+
+	if (chan == SENSOR_CHAN_PROX) {
+		val->val1 = data->sample_status;
+		val->val2 = 0;
+	} else {
+		return -ENOTSUP;
+	}
+
+	return 0;
+}
+
+#if CONFIG_SM351LT_TRIGGER
+static int sm351lt_attr_set(struct device *dev, enum sensor_channel chan,
+			    enum sensor_attribute attr,
+			    const struct sensor_value *val)
+{
+	struct sm351lt_data *data = dev->data;
+
+	if (chan == SENSOR_CHAN_PROX) {
+		if (attr == SENSOR_ATTR_SM351LT_TRIGGER_TYPE) {
+			/* Interrupt triggering type */
+			data->trigger_type = val->val1;
+		} else {
+			return -ENOTSUP;
+		}
+	} else {
+		return -ENOTSUP;
+	}
+
+	return 0;
+}
+
+static int sm351lt_attr_get(struct device *dev, enum sensor_channel chan,
+			    enum sensor_attribute attr,
+			    struct sensor_value *val)
+{
+	struct sm351lt_data *data = dev->data;
+
+	if (chan == SENSOR_CHAN_PROX) {
+		if (attr == SENSOR_ATTR_SM351LT_TRIGGER_TYPE) {
+			/* Interrupt triggering type */
+			val->val1 = data->trigger_type;
+			val->val2 = 0;
+		} else {
+			return -ENOTSUP;
+		}
+	} else {
+		return -ENOTSUP;
+	}
+
+	return 0;
+}
+#endif
+
+static const struct sensor_driver_api sm351lt_api_funcs = {
+	.sample_fetch = sm351lt_sample_fetch,
+	.channel_get = sm351lt_channel_get,
+#if CONFIG_SM351LT_TRIGGER
+	.attr_set = sm351lt_attr_set,
+	.attr_get = sm351lt_attr_get,
+	.trigger_set = sm351lt_trigger_set,
+#endif
+};
+
+static int sm351lt_init(struct device *dev)
+{
+	const struct sm351lt_config *const config = dev->config;
+	struct sm351lt_data *data = dev->data;
+	uint32_t ret;
+
+	data->bus = device_get_binding(config->bus_name);
+	if (!data->bus) {
+		LOG_ERR("gpio bus not found: %s", config->bus_name);
+		return -ENODEV;
+	}
+
+	ret = gpio_pin_configure(data->bus, config->gpio_pin,
+				 (config->gpio_flags | GPIO_INPUT));
+	if (ret) {
+		LOG_ERR("failed to configure gpio: %d", ret);
+		return ret;
+	}
+
+#if defined(CONFIG_SM351LT_TRIGGER)
+#if defined(CONFIG_SM351LT_TRIGGER_OWN_THREAD)
+	k_sem_init(&data->gpio_sem, 0, UINT_MAX);
+
+	k_thread_create(&data->thread, data->thread_stack,
+			CONFIG_SM351LT_THREAD_STACK_SIZE,
+			(k_thread_entry_t)sm351lt_thread, dev, NULL,
+			NULL, K_PRIO_COOP(CONFIG_SM351LT_THREAD_PRIORITY),
+			0, K_NO_WAIT);
+
+#if defined(CONFIG_THREAD_NAME) && defined(CONFIG_THREAD_MAX_NAME_LEN)
+	/* Sets up thread name as the device name */
+	k_thread_name_set(&data->thread, dev->name);
+#endif
+
+#elif defined(CONFIG_SM351LT_TRIGGER_GLOBAL_THREAD)
+	data->work.handler = sm351lt_work_cb;
+	data->dev = dev;
+#endif
+
+	data->trigger_type = GPIO_INT_DISABLE;
+
+	ret = gpio_pin_interrupt_configure(data->bus, config->gpio_pin,
+					   GPIO_INT_DISABLE);
+	if (ret) {
+		LOG_ERR("failed to configure gpio interrupt: %d", ret);
+		return ret;
+	}
+
+	/* Setup callback struct but do not add it yet */
+	gpio_init_callback(&data->gpio_cb, sm351lt_gpio_callback,
+			   BIT(config->gpio_pin));
+#endif
+
+	return 0;
+}
+
+/* Instantiation macros for each individual device. */
+#define SM351LT_DEFINE(inst)					     \
+	static struct sm351lt_data sm351lt_data_##inst;		     \
+	static const struct sm351lt_config sm351lt_config_##inst = { \
+		.bus_name =   DT_INST_GPIO_LABEL(inst, gpios),	     \
+		.gpio_pin =   DT_INST_GPIO_PIN(inst, gpios),	     \
+		.gpio_flags = DT_INST_GPIO_FLAGS(inst, gpios),	     \
+	};							     \
+								     \
+	DEVICE_AND_API_INIT(sm351lt_##inst,			     \
+			    DT_INST_LABEL(inst),		     \
+			    sm351lt_init,			     \
+			    &sm351lt_data_##inst,		     \
+			    &sm351lt_config_##inst,		     \
+			    POST_KERNEL,			     \
+			    CONFIG_SENSOR_INIT_PRIORITY,	     \
+			    &sm351lt_api_funcs);
+
+
+/* Main instantiation macro for every configured device in DTS. */
+DT_INST_FOREACH_STATUS_OKAY(SM351LT_DEFINE)

drivers/sensor/sm351lt/sm351lt.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2020, Laird Connectivity
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_DRIVERS_SENSOR_SM351LT_SM351LT_H_
+#define ZEPHYR_DRIVERS_SENSOR_SM351LT_SM351LT_H_
+
+#include <stdint.h>
+#include <drivers/gpio.h>
+#include <drivers/sensor.h>
+
+#define SENSOR_ATTR_SM351LT_TRIGGER_TYPE SENSOR_ATTR_PRIV_START
+
+struct sm351lt_config {
+	const char *bus_name;
+	gpio_pin_t gpio_pin;
+	gpio_dt_flags_t gpio_flags;
+};
+
+struct sm351lt_data {
+	struct device *bus;
+	bool sample_status;
+
+#ifdef CONFIG_SM351LT_TRIGGER
+	struct gpio_callback gpio_cb;
+
+	uint32_t trigger_type;
+	sensor_trigger_handler_t changed_handler;
+
+#if defined(CONFIG_SM351LT_TRIGGER_OWN_THREAD)
+	K_THREAD_STACK_MEMBER(thread_stack, CONFIG_SM351LT_THREAD_STACK_SIZE);
+	struct k_thread thread;
+	struct k_sem gpio_sem;
+#elif defined(CONFIG_SM351LT_TRIGGER_GLOBAL_THREAD)
+	struct k_work work;
+	struct device *dev;
+#endif
+
+#endif /* CONFIG_SM351LT_TRIGGER */
+};
+
+#endif /* ZEPHYR_DRIVERS_SENSOR_SM351LT_SM351LT_H_ */

dts/bindings/sensor/honeywell,sm351lt.yaml

@@ -0,0 +1,18 @@
+# Copyright (c) 2020, Laird Connectivity
+# SPDX-License-Identifier: Apache-2.0
+
+description: SM351LT magnetoresistive sensor
+
+compatible: "honeywell,sm351lt"
+
+include: base.yaml
+
+properties:
+   gpios:
+      type: phandle-array
+      required: true
+      description: GPIO connected to the sensor
+   label:
+      required: true
+      type: string
+      description: Driver label

tests/drivers/build_all/app.overlay

@@ -22,6 +22,8 @@
 			#gpio-cells = <0x2>;
 			label = "TEST_GPIO_1";
 			status = "okay";
+
+			#include "gpio.dtsi"
 		};
 
 		test_i2c: i2c@11112222 {

tests/drivers/build_all/gpio.dtsi

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2020, Laird Connectivity
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Application overlay for gpio devices
+ */
+
+test_gpio_sm351lt: sm351lt0 {
+	compatible = "honeywell,sm351lt";
+	gpios = <&test_gpio 0 0>;
+	label = "SM351LT0";
+};

tests/drivers/build_all/sensors_i_z.conf

@@ -32,6 +32,7 @@ CONFIG_SHT3XD=y
 CONFIG_SI7006=y
 CONFIG_SI7055=y
 CONFIG_SI7060=y
+CONFIG_SM351LT=y
 CONFIG_SX9500=y
 CONFIG_TEMP_NRF5=y
 CONFIG_TH02=y

tests/drivers/build_all/sensors_trigger_i_z.conf

@@ -1,3 +1,4 @@
+CONFIG_MAX_THREAD_BYTES=4
 CONFIG_TEST=y
 CONFIG_TEST_USERSPACE=y
 CONFIG_I2C=y
@@ -28,6 +29,8 @@ CONFIG_MPU6050=y
 CONFIG_MPU6050_TRIGGER_OWN_THREAD=y
 CONFIG_SHT3XD=y
 CONFIG_SHT3XD_TRIGGER_OWN_THREAD=y
+CONFIG_SM351LT=y
+CONFIG_SM351LT_TRIGGER_OWN_THREAD=y
 CONFIG_SX9500=y
 CONFIG_SX9500_TRIGGER_OWN_THREAD=y
 CONFIG_TMP007=y

tests/drivers/build_all/testcase.yaml

@@ -27,7 +27,7 @@ tests:
     min_ram: 32
     platform_exclude:  frdm_kw41z
     tags: drivers
-    depends_on: adc spi
+    depends_on: gpio adc spi
   sensors.build.a_h:
     build_only: true
     extra_args: CONF_FILE=sensors_a_h.conf
@@ -42,7 +42,7 @@ tests:
     min_ram: 32
     platform_exclude:  frdm_kw41z
     tags: drivers
-    depends_on: adc spi
+    depends_on: gpio adc spi
   sensors.build.stmemsc:
     build_only: true
     extra_args: CONF_FILE=sensors_stmemsc.conf