The BMP3xx and BMP5xx sensors have an interrupt pin which can be used as
a trigger for when there are data ready in the sensor for pick up.

This use case is used along with NORMAL_MODE in the sensor, which allows
the sensor to do consecutive measurements depending on the ODR rate value.

The trigger pin can be configured to be open-drain or push-pull and either
rising or falling edge.

No support is added yet for interrupts for FIFO, WATERMARK and out of range
values.

Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 225 ++++++++++++++++++++++++++++-
 drivers/iio/pressure/bmp280.h      |  21 +++
 2 files changed, 244 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 8c87f7ef28c9..0edd756ef8da 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -42,12 +42,14 @@
 #include <linux/module.h>
 #include <linux/nvmem-provider.h>
 #include <linux/pm_runtime.h>
+#include <linux/property.h>
 #include <linux/random.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 
 #include <linux/iio/buffer.h>
 #include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.h>
 
@@ -1278,6 +1280,63 @@ static irqreturn_t bme280_trigger_handler(int irq, void *p)
 	return IRQ_HANDLED;
 }
 
+static int __bmp280_trigger_probe(struct iio_dev *indio_dev,
+				  const struct iio_trigger_ops *trigger_ops,
+				  int (*int_pin_config)(struct bmp280_data *data),
+				  irq_handler_t irq_thread_handler)
+{
+	struct bmp280_data *data = iio_priv(indio_dev);
+	struct device *dev = data->dev;
+	u32 irq_type;
+	int ret, irq;
+
+	irq = fwnode_irq_get(dev_fwnode(dev), 0);
+	if (irq < 0)
+		return dev_err_probe(dev, irq, "No interrupt found.\n");
+
+	irq_type = irq_get_trigger_type(irq);
+	switch (irq_type) {
+	case IRQF_TRIGGER_RISING:
+		data->trig_active_high = true;
+		break;
+	case IRQF_TRIGGER_FALLING:
+		data->trig_active_high = false;
+		break;
+	default:
+		return dev_err_probe(dev, -EINVAL, "Invalid interrupt type specified.\n");
+	}
+
+	data->trig_open_drain =
+		fwnode_property_read_bool(dev_fwnode(dev), "int-open-drain");
+
+	ret = int_pin_config(data);
+	if (ret)
+		return ret;
+
+	data->trig = devm_iio_trigger_alloc(data->dev, "%s-dev%d",
+					    indio_dev->name,
+					    iio_device_id(indio_dev));
+	if (!data->trig)
+		return -ENOMEM;
+
+	data->trig->ops = trigger_ops;
+	iio_trigger_set_drvdata(data->trig, data);
+
+	ret = devm_request_threaded_irq(data->dev, irq, NULL,
+					irq_thread_handler, IRQF_ONESHOT,
+					indio_dev->name, indio_dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "request IRQ failed.\n");
+
+	ret = devm_iio_trigger_register(data->dev, data->trig);
+	if (ret)
+		return dev_err_probe(dev, ret, "iio trigger register failed.\n");
+
+	indio_dev->trig = iio_trigger_get(data->trig);
+
+	return 0;
+}
+
 static const u8 bme280_chip_ids[] = { BME280_CHIP_ID };
 static const int bme280_humid_coeffs[] = { 1000, 1024 };
 
@@ -1779,6 +1838,81 @@ static int bmp380_chip_config(struct bmp280_data *data)
 	return ret;
 }
 
+static void bmp380_trigger_reenable(struct iio_trigger *trig)
+{
+	struct bmp280_data *data = iio_trigger_get_drvdata(trig);
+	unsigned int tmp;
+	int ret;
+
+	ret = regmap_read(data->regmap, BMP380_REG_INT_STATUS, &tmp);
+	if (ret)
+		dev_err(data->dev, "Failed to reset interrupt.\n");
+}
+
+static int bmp380_data_rdy_trigger_set_state(struct iio_trigger *trig,
+					     bool state)
+{
+	struct bmp280_data *data = iio_trigger_get_drvdata(trig);
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	ret = regmap_update_bits(data->regmap, BMP380_REG_INT_CONTROL,
+				 BMP380_INT_CTRL_DRDY_EN,
+				 FIELD_PREP(BMP380_INT_CTRL_DRDY_EN, !!state));
+	if (ret)
+		dev_err(data->dev,
+			"Could not %s interrupt.\n", str_enable_disable(state));
+	return ret;
+}
+
+static const struct iio_trigger_ops bmp380_trigger_ops = {
+	.set_trigger_state = &bmp380_data_rdy_trigger_set_state,
+	.reenable = &bmp380_trigger_reenable,
+};
+
+static int bmp380_int_pin_config(struct bmp280_data *data)
+{
+	int pin_drive_cfg = FIELD_PREP(BMP380_INT_CTRL_OPEN_DRAIN,
+				       data->trig_open_drain);
+	int pin_level_cfg = FIELD_PREP(BMP380_INT_CTRL_LEVEL,
+				       data->trig_active_high);
+	int ret, int_pin_cfg = pin_drive_cfg | pin_level_cfg;
+
+	ret = regmap_update_bits(data->regmap, BMP380_REG_INT_CONTROL,
+				 BMP380_INT_CTRL_SETTINGS_MASK, int_pin_cfg);
+	if (ret)
+		dev_err(data->dev, "Could not set interrupt settings.\n");
+
+	return ret;
+}
+
+static irqreturn_t bmp380_irq_thread_handler(int irq, void *p)
+{
+	struct iio_dev *indio_dev = p;
+	struct bmp280_data *data = iio_priv(indio_dev);
+	unsigned int int_ctrl;
+	int ret;
+
+	scoped_guard(mutex, &data->lock) {
+		ret = regmap_read(data->regmap, BMP380_REG_INT_STATUS, &int_ctrl);
+		if (ret)
+			return IRQ_NONE;
+	}
+
+	if (FIELD_GET(BMP380_INT_STATUS_DRDY, int_ctrl))
+		iio_trigger_poll_nested(data->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int bmp380_trigger_probe(struct iio_dev *indio_dev)
+{
+	return __bmp280_trigger_probe(indio_dev, &bmp380_trigger_ops,
+				      bmp380_int_pin_config,
+				      bmp380_irq_thread_handler);
+}
+
 static irqreturn_t bmp380_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
@@ -1873,6 +2007,7 @@ const struct bmp280_chip_info bmp380_chip_info = {
 	.wait_conv = bmp380_wait_conv,
 	.preinit = bmp380_preinit,
 
+	.trigger_probe = bmp380_trigger_probe,
 	.trigger_handler = bmp380_trigger_handler,
 };
 EXPORT_SYMBOL_NS(bmp380_chip_info, IIO_BMP280);
@@ -2420,6 +2555,88 @@ static int bmp580_chip_config(struct bmp280_data *data)
 	return 0;
 }
 
+static void bmp580_trigger_reenable(struct iio_trigger *trig)
+{
+	struct bmp280_data *data = iio_trigger_get_drvdata(trig);
+	unsigned int tmp;
+	int ret;
+
+	ret = regmap_read(data->regmap, BMP580_REG_INT_STATUS, &tmp);
+	if (ret)
+		dev_err(data->dev, "Failed to reset interrupt.\n");
+}
+
+static int bmp580_data_rdy_trigger_set_state(struct iio_trigger *trig,
+					     bool state)
+{
+	struct bmp280_data *data = iio_trigger_get_drvdata(trig);
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	ret = regmap_update_bits(data->regmap, BMP580_REG_INT_CONFIG,
+				 BMP580_INT_CONFIG_INT_EN,
+				 FIELD_PREP(BMP580_INT_CONFIG_INT_EN, !!state));
+	if (ret)
+		dev_err(data->dev,
+			"Could not %s interrupt.\n", str_enable_disable(state));
+	return ret;
+}
+
+static const struct iio_trigger_ops bmp580_trigger_ops = {
+	.set_trigger_state = &bmp580_data_rdy_trigger_set_state,
+	.reenable = &bmp580_trigger_reenable,
+};
+
+static int bmp580_int_pin_config(struct bmp280_data *data)
+{
+	int pin_drive_cfg = FIELD_PREP(BMP580_INT_CONFIG_OPEN_DRAIN,
+				       data->trig_open_drain);
+	int pin_level_cfg = FIELD_PREP(BMP580_INT_CONFIG_LEVEL,
+				       data->trig_active_high);
+	int ret, int_pin_cfg = pin_drive_cfg | pin_level_cfg;
+
+	ret = regmap_update_bits(data->regmap, BMP580_REG_INT_CONFIG,
+				 BMP580_INT_CONFIG_MASK, int_pin_cfg);
+	if (ret) {
+		dev_err(data->dev, "Could not set interrupt settings.\n");
+		return ret;
+	}
+
+	ret = regmap_set_bits(data->regmap, BMP580_REG_INT_SOURCE,
+			      BMP580_INT_SOURCE_DRDY);
+	if (ret)
+		dev_err(data->dev, "Could not set interrupt source.\n");
+
+	return ret;
+}
+
+static irqreturn_t bmp580_irq_thread_handler(int irq, void *p)
+{
+	struct iio_dev *indio_dev = p;
+	struct bmp280_data *data = iio_priv(indio_dev);
+	unsigned int int_ctrl;
+	int ret;
+
+	scoped_guard(mutex, &data->lock) {
+		ret = regmap_read(data->regmap, BMP580_REG_INT_STATUS, &int_ctrl);
+		if (ret)
+			return IRQ_NONE;
+	}
+
+	if (FIELD_GET(BMP580_INT_STATUS_DRDY_MASK, int_ctrl))
+		iio_trigger_poll_nested(data->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int bmp580_trigger_probe(struct iio_dev *indio_dev)
+{
+	return __bmp280_trigger_probe(indio_dev, &bmp580_trigger_ops,
+				      bmp580_int_pin_config,
+				      bmp580_irq_thread_handler);
+}
+
 static irqreturn_t bmp580_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
@@ -2496,6 +2713,7 @@ const struct bmp280_chip_info bmp580_chip_info = {
 	.wait_conv = bmp580_wait_conv,
 	.preinit = bmp580_preinit,
 
+	.trigger_probe = bmp580_trigger_probe,
 	.trigger_handler = bmp580_trigger_handler,
 };
 EXPORT_SYMBOL_NS(bmp580_chip_info, IIO_BMP280);
@@ -3043,8 +3261,11 @@ int bmp280_common_probe(struct device *dev,
 	 * however as it happens, the BMP085 shares the chip ID of BMP180
 	 * so we look for an IRQ if we have that.
 	 */
-	if (irq > 0 && (chip_id  == BMP180_CHIP_ID)) {
-		ret = bmp085_fetch_eoc_irq(dev, name, irq, data);
+	if (irq > 0) {
+		if (chip_id == BMP180_CHIP_ID)
+			ret = bmp085_fetch_eoc_irq(dev, name, irq, data);
+		if (data->chip_info->trigger_probe)
+			ret = data->chip_info->trigger_probe(indio_dev);
 		if (ret)
 			return ret;
 	}
diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
index c9840b8d58b0..0c32b6430677 100644
--- a/drivers/iio/pressure/bmp280.h
+++ b/drivers/iio/pressure/bmp280.h
@@ -55,8 +55,17 @@
 #define BMP580_CMD_NVM_WRITE_SEQ_1	0xA0
 #define BMP580_CMD_SOFT_RESET		0xB6
 
+#define BMP580_INT_STATUS_DRDY_MASK	BIT(0)
 #define BMP580_INT_STATUS_POR_MASK	BIT(4)
 
+#define BMP580_INT_SOURCE_DRDY		BIT(0)
+
+#define BMP580_INT_CONFIG_MASK		GENMASK(3, 0)
+#define BMP580_INT_CONFIG_LATCH		BIT(0)
+#define BMP580_INT_CONFIG_LEVEL		BIT(1)
+#define BMP580_INT_CONFIG_OPEN_DRAIN	BIT(2)
+#define BMP580_INT_CONFIG_INT_EN	BIT(3)
+
 #define BMP580_STATUS_CORE_RDY_MASK	BIT(0)
 #define BMP580_STATUS_NVM_RDY_MASK	BIT(1)
 #define BMP580_STATUS_NVM_ERR_MASK	BIT(2)
@@ -175,6 +184,14 @@
 #define BMP380_TEMP_MEAS_OFFSET		163
 #define BMP380_PRESS_MEAS_OFFSET	392
 
+#define BMP380_INT_STATUS_DRDY		BIT(3)
+
+#define BMP380_INT_CTRL_SETTINGS_MASK	GENMASK(2, 0)
+#define BMP380_INT_CTRL_OPEN_DRAIN	BIT(0)
+#define BMP380_INT_CTRL_LEVEL		BIT(1)
+#define BMP380_INT_CTRL_LATCH		BIT(2)
+#define BMP380_INT_CTRL_DRDY_EN		BIT(6)
+
 #define BMP380_MIN_TEMP			-4000
 #define BMP380_MAX_TEMP			8500
 #define BMP380_MIN_PRES			3000000
@@ -406,6 +423,9 @@ struct bmp280_data {
 	struct regmap *regmap;
 	struct completion done;
 	bool use_eoc;
+	bool trig_open_drain;
+	bool trig_active_high;
+	struct iio_trigger *trig;
 	const struct bmp280_chip_info *chip_info;
 	union {
 		struct bmp180_calib bmp180;
@@ -510,6 +530,7 @@ struct bmp280_chip_info {
 	int (*set_mode)(struct bmp280_data *data, enum bmp280_op_mode mode);
 	int (*wait_conv)(struct bmp280_data *data);
 
+	int (*trigger_probe)(struct iio_dev *indio_dev);
 	irqreturn_t (*trigger_handler)(int irq, void *p);
 };
 
-- 
2.25.1