driver/sensor: lis3mdl: Fix DRDY interrupt

The LIS3MDL sensor provides two different pins for handling
interrupts: the DRDY, that triggers new data sample availability,
and INT, that goes off when data sample exceeds a given threshold.

The driver handled data ready triggers only, which does not
require sensor configuration at all. Moreover a dummy read is
required when the data ready is configured to re-trigger a new
interrupt.

Signed-off-by: Armando Visconti <[email protected]>

Author: avisconti

drivers/sensor/lis3mdl/lis3mdl_trigger.c

@@ -20,9 +20,14 @@ int lis3mdl_trigger_set(struct device *dev,
 			sensor_trigger_handler_t handler)
 {
 	struct lis3mdl_data *drv_data = dev->driver_data;
+	s16_t buf[3];
 
 	__ASSERT_NO_MSG(trig->type == SENSOR_TRIG_DATA_READY);
 
+	/* dummy read: re-trigger interrupt */
+	i2c_burst_read(drv_data->i2c, DT_INST_0_ST_LIS3MDL_MAGN_BASE_ADDRESS,
+			   LIS3MDL_REG_SAMPLE_START, (u8_t *)buf, 6);
+
 	gpio_pin_interrupt_configure(drv_data->gpio,
 			DT_INST_0_ST_LIS3MDL_MAGN_IRQ_GPIOS_PIN,
 			GPIO_INT_DISABLE);
@@ -133,13 +138,6 @@ int lis3mdl_init_interrupt(struct device *dev)
 		return -EIO;
 	}
 
-	/* enable interrupt */
-	if (i2c_reg_write_byte(drv_data->i2c, DT_INST_0_ST_LIS3MDL_MAGN_BASE_ADDRESS,
-			       LIS3MDL_REG_INT_CFG, LIS3MDL_INT_XYZ_EN) < 0) {
-		LOG_DBG("Could not enable interrupt.");
-		return -EIO;
-	}
-
 #if defined(CONFIG_LIS3MDL_TRIGGER_OWN_THREAD)
 	k_sem_init(&drv_data->gpio_sem, 0, UINT_MAX);