fxos8700: Add support for data ready trigger

Adds general sensor triggering support to the fxos8700 driver, including
options for the driver to use its own thread or the global workqueue
thread to handle sensor interrupts. Adds specific support to handle the
data ready sensor trigger.

Jira: ZEP-1395
Change-Id: I092f22e35747b92a88eb71a3d162a4fc16227b45
Signed-off-by: Maureen Helm <maureen.helm@nxp.com>

drivers/sensor/fxos8700/Kconfig

@@ -82,3 +82,52 @@ config FXOS8700_RANGE_2G
 	bool "2g (0.244 mg/LSB)"
 
 endchoice
+
+choice
+	prompt "Trigger mode"
+	depends on FXOS8700
+	default FXOS8700_TRIGGER_NONE
+
+config FXOS8700_TRIGGER_NONE
+	bool "No trigger"
+
+config FXOS8700_TRIGGER_GLOBAL_THREAD
+	bool "Use global thread"
+	select FXOS8700_TRIGGER
+
+config FXOS8700_TRIGGER_OWN_THREAD
+	bool "Use own thread"
+	select FXOS8700_TRIGGER
+
+endchoice
+
+config FXOS8700_TRIGGER
+	bool
+	depends on FXOS8700
+	default n
+
+config FXOS8700_GPIO_NAME
+	string "GPIO device name"
+	depends on FXOS8700_TRIGGER
+
+config FXOS8700_GPIO_PIN
+	int "GPIO pin"
+	depends on FXOS8700_TRIGGER
+
+config FXOS8700_DRDY_INT1
+	bool "Data ready interrupt to INT1 pin"
+	depends on FXOS8700_TRIGGER
+	default n
+	help
+	Say Y to route data ready interrupt to INT1 pin. Say N to route to INT2
+	pin.
+
+config FXOS8700_THREAD_PRIORITY
+	int "Own thread priority"
+	depends on FXOS8700_TRIGGER_OWN_THREAD
+	default 10
+
+config FXOS8700_THREAD_STACK_SIZE
+	int "Own thread stack size"
+	depends on FXOS8700_TRIGGER_OWN_THREAD
+	default 1024

drivers/sensor/fxos8700/Makefile

@@ -16,3 +16,4 @@
 #
 
 obj-$(CONFIG_FXOS8700) += fxos8700.o
+obj-$(CONFIG_FXOS8700_TRIGGER) += fxos8700_trigger.o

drivers/sensor/fxos8700/fxos8700.c

@@ -214,6 +214,35 @@ static int fxos8700_channel_get(struct device *dev, enum sensor_channel chan,
 	return ret;
 }
 
+int fxos8700_get_power(struct device *dev, enum fxos8700_power *power)
+{
+	const struct fxos8700_config *config = dev->config->config_info;
+	struct fxos8700_data *data = dev->driver_data;
+	uint8_t val = *power;
+
+	if (i2c_reg_read_byte(data->i2c, config->i2c_address,
+			      FXOS8700_REG_CTRLREG1,
+			      &val)) {
+		SYS_LOG_DBG("Could not get power setting");
+		return -EIO;
+	}
+	val &= FXOS8700_M_CTRLREG1_MODE_MASK;
+	*power = val;
+
+	return 0;
+}
+
+int fxos8700_set_power(struct device *dev, enum fxos8700_power power)
+{
+	const struct fxos8700_config *config = dev->config->config_info;
+	struct fxos8700_data *data = dev->driver_data;
+
+	return i2c_reg_update_byte(data->i2c, config->i2c_address,
+				   FXOS8700_REG_CTRLREG1,
+				   FXOS8700_CTRLREG1_ACTIVE_MASK,
+				   power);
+}
+
 static int fxos8700_init(struct device *dev)
 {
 	const struct fxos8700_config *config = dev->config->config_info;
@@ -285,11 +314,15 @@ static int fxos8700_init(struct device *dev)
 		return -EIO;
 	}
 
+#if CONFIG_FXOS8700_TRIGGER
+	if (fxos8700_trigger_init(dev)) {
+		SYS_LOG_DBG("Could not initialize interrupts");
+		return -EIO;
+	}
+#endif
+
 	/* Set active */
-	if (i2c_reg_update_byte(data->i2c, config->i2c_address,
+	if (fxos8700_set_power(dev, FXOS8700_POWER_ACTIVE)) {
-				FXOS8700_REG_CTRLREG1,
-				FXOS8700_CTRLREG1_ACTIVE_MASK,
-				FXOS8700_CTRLREG1_ACTIVE_MASK)) {
 		SYS_LOG_DBG("Could not set active");
 		return -EIO;
 	}
@@ -305,6 +338,9 @@ static int fxos8700_init(struct device *dev)
 static const struct sensor_driver_api fxos8700_driver_api = {
 	.sample_fetch = fxos8700_sample_fetch,
 	.channel_get = fxos8700_channel_get,
+#if CONFIG_FXOS8700_TRIGGER
+	.trigger_set = fxos8700_trigger_set,
+#endif
 };
 
 static const struct fxos8700_config fxos8700_config = {
@@ -334,6 +370,10 @@ static const struct fxos8700_config fxos8700_config = {
 #else
 	.range = FXOS8700_RANGE_2G,
 #endif
+#ifdef CONFIG_FXOS8700_TRIGGER
+	.gpio_name = CONFIG_FXOS8700_GPIO_NAME,
+	.gpio_pin = CONFIG_FXOS8700_GPIO_PIN,
+#endif
 };
 
 static struct fxos8700_data fxos8700_data;

drivers/sensor/fxos8700/fxos8700.h

@@ -16,6 +16,7 @@
 
 #include <sensor.h>
 #include <i2c.h>
+#include <gpio.h>
 
 #define SYS_LOG_DOMAIN "FXOS8700"
 #define SYS_LOG_LEVEL CONFIG_SYS_LOG_SENSOR_LEVEL
@@ -35,6 +36,8 @@
 #define FXOS8700_REG_M_CTRLREG1			0x5b
 #define FXOS8700_REG_M_CTRLREG2			0x5c
 
+#define FXOS8700_DRDY_MASK			(1 << 0)
+
 #define FXOS8700_XYZ_DATA_CFG_FS_MASK		0x03
 
 #define FXOS8700_CTRLREG1_ACTIVE_MASK		0x01
@@ -85,6 +88,10 @@ enum fxos8700_channel {
 
 struct fxos8700_config {
 	char *i2c_name;
+#ifdef CONFIG_FXOS8700_TRIGGER
+	char *gpio_name;
+	uint8_t gpio_pin;
+#endif
 	uint8_t i2c_address;
 	uint8_t whoami;
 	enum fxos8700_mode mode;
@@ -97,5 +104,28 @@ struct fxos8700_config {
 struct fxos8700_data {
 	struct device *i2c;
 	struct k_sem sem;
+#ifdef CONFIG_FXOS8700_TRIGGER
+	struct device *gpio;
+	struct gpio_callback gpio_cb;
+	sensor_trigger_handler_t drdy_handler;
+#endif
+#ifdef CONFIG_FXOS8700_TRIGGER_OWN_THREAD
+	char __stack thread_stack[CONFIG_FXOS8700_THREAD_STACK_SIZE];
+	struct k_sem trig_sem;
+#endif
+#ifdef CONFIG_FXOS8700_TRIGGER_GLOBAL_THREAD
+	struct k_work work;
+	struct device *dev;
+#endif
 	int16_t raw[FXOS8700_MAX_NUM_CHANNELS];
 };
+
+int fxos8700_get_power(struct device *dev, enum fxos8700_power *power);
+int fxos8700_set_power(struct device *dev, enum fxos8700_power power);
+
+#if CONFIG_FXOS8700_TRIGGER
+int fxos8700_trigger_init(struct device *dev);
+int fxos8700_trigger_set(struct device *dev,
+			 const struct sensor_trigger *trig,
+			 sensor_trigger_handler_t handler);
+#endif

drivers/sensor/fxos8700/fxos8700_trigger.c

@@ -0,0 +1,208 @@
+/*
+ * Copyright (c) 2016 Freescale Semiconductor, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <fxos8700.h>
+
+static void fxos8700_gpio_callback(struct device *dev,
+				   struct gpio_callback *cb,
+				   uint32_t pin)
+{
+	struct fxos8700_data *data =
+		CONTAINER_OF(cb, struct fxos8700_data, gpio_cb);
+
+	gpio_pin_disable_callback(dev, pin);
+
+#if defined(CONFIG_FXOS8700_TRIGGER_OWN_THREAD)
+	k_sem_give(&data->trig_sem);
+#elif defined(CONFIG_FXOS8700_TRIGGER_GLOBAL_THREAD)
+	k_work_submit(&data->work);
+#endif
+}
+
+static int fxos8700_handle_drdy_int(struct device *dev)
+{
+	struct fxos8700_data *data = dev->driver_data;
+
+	struct sensor_trigger drdy_trig = {
+		.type = SENSOR_TRIG_DATA_READY,
+		.chan = SENSOR_CHAN_ALL,
+	};
+
+	if (data->drdy_handler) {
+		data->drdy_handler(dev, &drdy_trig);
+	}
+
+	return 0;
+}
+
+static void fxos8700_handle_int(void *arg)
+{
+	struct device *dev = (struct device *)arg;
+	const struct fxos8700_config *config = dev->config->config_info;
+	struct fxos8700_data *data = dev->driver_data;
+	uint8_t int_source;
+
+	k_sem_take(&data->sem, K_FOREVER);
+
+	if (i2c_reg_read_byte(data->i2c, config->i2c_address,
+			      FXOS8700_REG_INT_SOURCE,
+			      &int_source)) {
+		SYS_LOG_DBG("Could not read interrupt source");
+		int_source = 0;
+	}
+
+	k_sem_give(&data->sem);
+
+	if (int_source & FXOS8700_DRDY_MASK) {
+		fxos8700_handle_drdy_int(dev);
+	}
+
+	gpio_pin_enable_callback(data->gpio, config->gpio_pin);
+}
+
+#ifdef CONFIG_FXOS8700_TRIGGER_OWN_THREAD
+static void fxos8700_thread_main(void *arg1, void *unused1, void *unused2)
+{
+	struct device *dev = (struct device *)arg1;
+	struct fxos8700_data *data = dev->driver_data;
+
+	while (true) {
+		k_sem_take(&data->trig_sem, K_FOREVER);
+		fxos8700_handle_int(dev);
+	}
+}
+#endif
+
+#ifdef CONFIG_FXOS8700_TRIGGER_GLOBAL_THREAD
+static void fxos8700_work_handler(struct k_work *work)
+{
+	struct fxos8700_data *data =
+		CONTAINER_OF(work, struct fxos8700_data, work);
+
+	fxos8700_handle_int(data->dev);
+}
+#endif
+
+int fxos8700_trigger_set(struct device *dev,
+			 const struct sensor_trigger *trig,
+			 sensor_trigger_handler_t handler)
+{
+	const struct fxos8700_config *config = dev->config->config_info;
+	struct fxos8700_data *data = dev->driver_data;
+	enum fxos8700_power power;
+	uint8_t mask;
+	int ret = 0;
+
+	k_sem_take(&data->sem, K_FOREVER);
+
+	switch (trig->type) {
+	case SENSOR_TRIG_DATA_READY:
+		mask = FXOS8700_DRDY_MASK;
+		data->drdy_handler = handler;
+		break;
+	default:
+		SYS_LOG_DBG("Unsupported sensor trigger");
+		ret = -ENOTSUP;
+		goto exit;
+	}
+
+	/* The sensor must be in standby mode when writing the configuration
+	 * registers, therefore get the current power mode so we can restore it
+	 * later.
+	 */
+	if (fxos8700_get_power(dev, &power)) {
+		SYS_LOG_DBG("Could not get power mode");
+		ret = -EIO;
+		goto exit;
+	}
+
+	/* Put the sensor in standby mode */
+	if (fxos8700_set_power(dev, FXOS8700_POWER_STANDBY)) {
+		SYS_LOG_DBG("Could not set standby mode");
+		ret = -EIO;
+		goto exit;
+	}
+
+	/* Configure the sensor interrupt */
+	if (i2c_reg_update_byte(data->i2c, config->i2c_address,
+				FXOS8700_REG_CTRLREG4,
+				mask,
+				handler ? mask : 0)) {
+		SYS_LOG_DBG("Could not configure interrupt");
+		ret = -EIO;
+		goto exit;
+	}
+
+	/* Restore the previous power mode */
+	if (fxos8700_set_power(dev, power)) {
+		SYS_LOG_DBG("Could not restore power mode");
+		ret = -EIO;
+		goto exit;
+	}
+
+exit:
+	k_sem_give(&data->sem);
+
+	return ret;
+}
+
+int fxos8700_trigger_init(struct device *dev)
+{
+	const struct fxos8700_config *config = dev->config->config_info;
+	struct fxos8700_data *data = dev->driver_data;
+	uint8_t ctrl_reg5;
+
+#if defined(CONFIG_FXOS8700_TRIGGER_OWN_THREAD)
+	k_sem_init(&data->trig_sem, 0, UINT_MAX);
+	k_thread_spawn(data->thread_stack, CONFIG_FXOS8700_THREAD_STACK_SIZE,
+		       fxos8700_thread_main, dev, 0, NULL,
+		       K_PRIO_COOP(CONFIG_FXOS8700_THREAD_PRIORITY), 0, 0);
+#elif defined(CONFIG_FXOS8700_TRIGGER_GLOBAL_THREAD)
+	data->work.handler = fxos8700_work_handler;
+	data->dev = dev;
+#endif
+
+	/* Route the interrupts to INT1/INT2 pins */
+	ctrl_reg5 = 0;
+#if CONFIG_FXOS8700_DRDY_INT1
+	ctrl_reg5 |= FXOS8700_DRDY_MASK;
+#endif
+	if (i2c_reg_write_byte(data->i2c, config->i2c_address,
+			       FXOS8700_REG_CTRLREG5, ctrl_reg5)) {
+		SYS_LOG_DBG("Could not configure interrupt pin routing");
+		return -EIO;
+	}
+
+	/* Get the GPIO device */
+	data->gpio = device_get_binding(config->gpio_name);
+	if (data->gpio == NULL) {
+		SYS_LOG_DBG("Could not find GPIO device");
+		return -EINVAL;
+	}
+
+	gpio_pin_configure(data->gpio, config->gpio_pin,
+			   GPIO_DIR_IN | GPIO_INT | GPIO_INT_EDGE |
+			   GPIO_INT_ACTIVE_LOW | GPIO_INT_DEBOUNCE);
+
+	gpio_init_callback(&data->gpio_cb, fxos8700_gpio_callback,
+			   BIT(config->gpio_pin));
+
+	gpio_add_callback(data->gpio, &data->gpio_cb);
+
+	gpio_pin_enable_callback(data->gpio, config->gpio_pin);
+
+	return 0;
+}