iio: imu: inv_icm42600: add device interrupt

Add INT1 interrupt support. Support interrupt edge and level,
active high or low. Push-pull or open-drain configurations.

Interrupt will be used to read data from the FIFO.

Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/inv_icm42600/inv_icm42600.h

@@ -372,7 +372,7 @@ int inv_icm42600_set_temp_conf(struct inv_icm42600_state *st, bool enable,
 int inv_icm42600_debugfs_reg(struct iio_dev *indio_dev, unsigned int reg,
 			     unsigned int writeval, unsigned int *readval);
 
-int inv_icm42600_core_probe(struct regmap *regmap, int chip,
+int inv_icm42600_core_probe(struct regmap *regmap, int chip, int irq,
 			    inv_icm42600_bus_setup bus_setup);
 
 struct iio_dev *inv_icm42600_gyro_init(struct inv_icm42600_state *st);

drivers/iio/imu/inv_icm42600/inv_icm42600_core.c

@@ -9,8 +9,11 @@
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/mutex.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/regulator/consumer.h>
 #include <linux/pm_runtime.h>
+#include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/iio/iio.h>
 
@@ -408,6 +411,82 @@ static int inv_icm42600_setup(struct inv_icm42600_state *st,
 	return inv_icm42600_set_conf(st, hw->conf);
 }
 
+static irqreturn_t inv_icm42600_irq_handler(int irq, void *_data)
+{
+	struct inv_icm42600_state *st = _data;
+	struct device *dev = regmap_get_device(st->map);
+	unsigned int status;
+	int ret;
+
+	mutex_lock(&st->lock);
+
+	ret = regmap_read(st->map, INV_ICM42600_REG_INT_STATUS, &status);
+	if (ret)
+		goto out_unlock;
+
+	/* FIFO full */
+	if (status & INV_ICM42600_INT_STATUS_FIFO_FULL)
+		dev_warn(dev, "FIFO full data lost!\n");
+
+out_unlock:
+	mutex_unlock(&st->lock);
+	return IRQ_HANDLED;
+}
+
+/**
+ * inv_icm42600_irq_init() - initialize int pin and interrupt handler
+ * @st:		driver internal state
+ * @irq:	irq number
+ * @irq_type:	irq trigger type
+ * @open_drain:	true if irq is open drain, false for push-pull
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+static int inv_icm42600_irq_init(struct inv_icm42600_state *st, int irq,
+				 int irq_type, bool open_drain)
+{
+	struct device *dev = regmap_get_device(st->map);
+	unsigned int val;
+	int ret;
+
+	/* configure INT1 interrupt: default is active low on edge */
+	switch (irq_type) {
+	case IRQF_TRIGGER_RISING:
+	case IRQF_TRIGGER_HIGH:
+		val = INV_ICM42600_INT_CONFIG_INT1_ACTIVE_HIGH;
+		break;
+	default:
+		val = INV_ICM42600_INT_CONFIG_INT1_ACTIVE_LOW;
+		break;
+	}
+
+	switch (irq_type) {
+	case IRQF_TRIGGER_LOW:
+	case IRQF_TRIGGER_HIGH:
+		val |= INV_ICM42600_INT_CONFIG_INT1_LATCHED;
+		break;
+	default:
+		break;
+	}
+
+	if (!open_drain)
+		val |= INV_ICM42600_INT_CONFIG_INT1_PUSH_PULL;
+
+	ret = regmap_write(st->map, INV_ICM42600_REG_INT_CONFIG, val);
+	if (ret)
+		return ret;
+
+	/* Deassert async reset for proper INT pin operation (cf datasheet) */
+	ret = regmap_update_bits(st->map, INV_ICM42600_REG_INT_CONFIG1,
+				 INV_ICM42600_INT_CONFIG1_ASYNC_RESET, 0);
+	if (ret)
+		return ret;
+
+	return devm_request_threaded_irq(dev, irq, NULL,
+					 inv_icm42600_irq_handler, irq_type,
+					 "inv_icm42600", st);
+}
+
 static int inv_icm42600_enable_regulator_vddio(struct inv_icm42600_state *st)
 {
 	int ret;
@@ -452,18 +531,34 @@ static void inv_icm42600_disable_pm(void *_data)
 	pm_runtime_disable(dev);
 }
 
-int inv_icm42600_core_probe(struct regmap *regmap, int chip,
+int inv_icm42600_core_probe(struct regmap *regmap, int chip, int irq,
 			    inv_icm42600_bus_setup bus_setup)
 {
 	struct device *dev = regmap_get_device(regmap);
 	struct inv_icm42600_state *st;
+	struct irq_data *irq_desc;
+	int irq_type;
+	bool open_drain;
 	int ret;
 
 	if (chip < 0 || chip >= INV_CHIP_NB) {
 		dev_err(dev, "invalid chip = %d\n", chip);
 		return -ENODEV;
 	}
 
+	/* get irq properties, set trigger falling by default */
+	irq_desc = irq_get_irq_data(irq);
+	if (!irq_desc) {
+		dev_err(dev, "could not find IRQ %d\n", irq);
+		return -EINVAL;
+	}
+
+	irq_type = irqd_get_trigger_type(irq_desc);
+	if (!irq_type)
+		irq_type = IRQF_TRIGGER_FALLING;
+
+	open_drain = device_property_read_bool(dev, "drive-open-drain");
+
 	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
 	if (!st)
 		return -ENOMEM;
@@ -517,6 +612,10 @@ int inv_icm42600_core_probe(struct regmap *regmap, int chip,
 	if (IS_ERR(st->indio_accel))
 		return PTR_ERR(st->indio_accel);
 
+	ret = inv_icm42600_irq_init(st, irq, irq_type, open_drain);
+	if (ret)
+		return ret;
+
 	/* setup runtime power management */
 	ret = pm_runtime_set_active(dev);
 	if (ret)

drivers/iio/imu/inv_icm42600/inv_icm42600_i2c.c

@@ -64,7 +64,8 @@ static int inv_icm42600_probe(struct i2c_client *client)
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);
 
-	return inv_icm42600_core_probe(regmap, chip, inv_icm42600_i2c_bus_setup);
+	return inv_icm42600_core_probe(regmap, chip, client->irq,
+				       inv_icm42600_i2c_bus_setup);
 }
 
 static const struct of_device_id inv_icm42600_of_matches[] = {

drivers/iio/imu/inv_icm42600/inv_icm42600_spi.c

@@ -63,7 +63,8 @@ static int inv_icm42600_probe(struct spi_device *spi)
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);
 
-	return inv_icm42600_core_probe(regmap, chip, inv_icm42600_spi_bus_setup);
+	return inv_icm42600_core_probe(regmap, chip, spi->irq,
+				       inv_icm42600_spi_bus_setup);
 }
 
 static const struct of_device_id inv_icm42600_of_matches[] = {