iio: mpl3115: add support for DRDY interrupt

index 579da60ef441..1da78081ca7e 100644
@@ -148,47 +148,53 @@ static int mpl3115_read_raw(struct iio_dev *indio_dev,
 	return -EINVAL;
 }
 
-static irqreturn_t mpl3115_trigger_handler(int irq, void *p)
+static int mpl3115_fill_trig_buffer(struct iio_dev *indio_dev, u8 *buffer)
 {
-	struct iio_poll_func *pf = p;
-	struct iio_dev *indio_dev = pf->indio_dev;
 	struct mpl3115_data *data = iio_priv(indio_dev);
-	/*
-	 * 32-bit channel + 16-bit channel + padding + ts
-	 * Note that it is possible for only one of the first 2
-	 * channels to be enabled. If that happens, the first element
-	 * of the buffer may be either 16 or 32-bits.  As such we cannot
-	 * use a simple structure definition to express this data layout.
-	 */
-	u8 buffer[16] __aligned(8) = { };
 	int ret, pos = 0;
 
-	mutex_lock(&data->lock);
 	ret = mpl3115_request(data);
-	if (ret < 0) {
-		mutex_unlock(&data->lock);
-		goto done;
-	}
+	if (ret < 0)
+		return ret;
 
 	if (test_bit(0, indio_dev->active_scan_mask)) {
 		ret = i2c_smbus_read_i2c_block_data(data->client,
 			MPL3115_OUT_PRESS, 3, &buffer[pos]);
-		if (ret < 0) {
-			mutex_unlock(&data->lock);
-			goto done;
-		}
+		if (ret < 0)
+			return ret;
 		pos += 4;
 	}
 
 	if (test_bit(1, indio_dev->active_scan_mask)) {
 		ret = i2c_smbus_read_i2c_block_data(data->client,
 			MPL3115_OUT_TEMP, 2, &buffer[pos]);
-		if (ret < 0) {
-			mutex_unlock(&data->lock);
-			goto done;
-		}
+		if (ret < 0)
+			return ret;
 	}
+
+	return 0;
+}
+
+static irqreturn_t mpl3115_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct mpl3115_data *data = iio_priv(indio_dev);
+	/*
+	 * 32-bit channel + 16-bit channel + padding + ts
+	 * Note that it is possible for only one of the first 2
+	 * channels to be enabled. If that happens, the first element
+	 * of the buffer may be either 16 or 32-bits.  As such we cannot
+	 * use a simple structure definition to express this data layout.
+	 */
+	u8 buffer[16] __aligned(8) = { };
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = mpl3115_fill_trig_buffer(indio_dev, buffer);
 	mutex_unlock(&data->lock);
+	if (ret)
+		goto done;
 
 	iio_push_to_buffers_with_ts(indio_dev, buffer, sizeof(buffer),
 				    iio_get_time_ns(indio_dev));

index 1da78081ca7e..61830edd959b 100644
@@ -30,10 +30,10 @@
 #define MPL3115_STATUS_PRESS_RDY BIT(2)
 #define MPL3115_STATUS_TEMP_RDY BIT(1)
 
-#define MPL3115_CTRL_RESET BIT(2) /* software reset */
-#define MPL3115_CTRL_OST BIT(1) /* initiate measurement */
-#define MPL3115_CTRL_ACTIVE BIT(0) /* continuous measurement */
-#define MPL3115_CTRL_OS_258MS (BIT(5) | BIT(4)) /* 64x oversampling */
+#define MPL3115_CTRL1_RESET BIT(2) /* software reset */
+#define MPL3115_CTRL1_OST BIT(1) /* initiate measurement */
+#define MPL3115_CTRL1_ACTIVE BIT(0) /* continuous measurement */
+#define MPL3115_CTRL1_OS_258MS GENMASK(5, 4) /* 64x oversampling */
 
 struct mpl3115_data {
 	struct i2c_client *client;

@@ -47,7 +47,7 @@ static int mpl3115_request(struct mpl3115_data *data)
 
 	/* trigger measurement */
 	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
-		data->ctrl_reg1 | MPL3115_CTRL_OST);
+		data->ctrl_reg1 | MPL3115_CTRL1_OST);
 	if (ret < 0)
 		return ret;
 

@@ -56,7 +56,7 @@ static int mpl3115_request(struct mpl3115_data *data)
 		if (ret < 0)
 			return ret;
 		/* wait for data ready, i.e. OST cleared */
-		if (!(ret & MPL3115_CTRL_OST))
+		if (!(ret & MPL3115_CTRL1_OST))
 			break;
 		msleep(20);
 	}

@@ -268,10 +268,10 @@ static int mpl3115_probe(struct i2c_client *client)
 
 	/* software reset, I2C transfer is aborted (fails) */
 	i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
-		MPL3115_CTRL_RESET);
+		MPL3115_CTRL1_RESET);
 	msleep(50);
 
-	data->ctrl_reg1 = MPL3115_CTRL_OS_258MS;
+	data->ctrl_reg1 = MPL3115_CTRL1_OS_258MS;
 	ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
 		data->ctrl_reg1);
 	if (ret < 0)

@@ -295,7 +295,7 @@ static int mpl3115_probe(struct i2c_client *client)
 static int mpl3115_standby(struct mpl3115_data *data)
 {
 	return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
-		data->ctrl_reg1 & ~MPL3115_CTRL_ACTIVE);
+		data->ctrl_reg1 & ~MPL3115_CTRL1_ACTIVE);
 }
 
 static void mpl3115_remove(struct i2c_client *client)

index 61830edd959b..e1b2c9f2bb43 100644
@@ -7,40 +7,66 @@
  * (7-bit I2C slave address 0x60)
  *
  * TODO: FIFO buffer, altimeter mode, oversampling, continuous mode,
- * interrupts, user offset correction, raw mode
+ * user offset correction, raw mode
  */
 
-#include <linux/module.h>
+#include <linux/cleanup.h>
+#include <linux/delay.h>
 #include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/property.h>
+
+#include <linux/iio/buffer.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
-#include <linux/iio/trigger_consumer.h>
-#include <linux/iio/buffer.h>
 #include <linux/iio/triggered_buffer.h>
-#include <linux/delay.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/trigger.h>
 
 #define MPL3115_STATUS 0x00
 #define MPL3115_OUT_PRESS 0x01 /* MSB first, 20 bit */
 #define MPL3115_OUT_TEMP 0x04 /* MSB first, 12 bit */
 #define MPL3115_WHO_AM_I 0x0c
+#define MPL3115_INT_SOURCE 0x12
+#define MPL3115_PT_DATA_CFG 0x13
 #define MPL3115_CTRL_REG1 0x26
+#define MPL3115_CTRL_REG3 0x28
+#define MPL3115_CTRL_REG4 0x29
+#define MPL3115_CTRL_REG5 0x2a
 
 #define MPL3115_DEVICE_ID 0xc4
 
 #define MPL3115_STATUS_PRESS_RDY BIT(2)
 #define MPL3115_STATUS_TEMP_RDY BIT(1)
 
+#define MPL3115_INT_SRC_DRDY BIT(7)
+
+#define MPL3115_PT_DATA_EVENT_ALL GENMASK(2, 0)
+
 #define MPL3115_CTRL1_RESET BIT(2) /* software reset */
 #define MPL3115_CTRL1_OST BIT(1) /* initiate measurement */
 #define MPL3115_CTRL1_ACTIVE BIT(0) /* continuous measurement */
 #define MPL3115_CTRL1_OS_258MS GENMASK(5, 4) /* 64x oversampling */
 
+#define MPL3115_CTRL3_IPOL1 BIT(5)
+#define MPL3115_CTRL3_IPOL2 BIT(1)
+
+#define MPL3115_CTRL4_INT_EN_DRDY BIT(7)
+
+#define MPL3115_CTRL5_INT_CFG_DRDY BIT(7)
+
 struct mpl3115_data {
 	struct i2c_client *client;
+	struct iio_trigger *drdy_trig;
 	struct mutex lock;
 	u8 ctrl_reg1;
 };
 
+enum mpl3115_irq_pin {
+	MPL3115_IRQ_INT1,
+	MPL3115_IRQ_INT2,
+};
+
 static int mpl3115_request(struct mpl3115_data *data)
 {
 	int ret, tries = 15;

@@ -153,9 +179,11 @@ static int mpl3115_fill_trig_buffer(struct iio_dev *indio_dev, u8 *buffer)
 	struct mpl3115_data *data = iio_priv(indio_dev);
 	int ret, pos = 0;
 
-	ret = mpl3115_request(data);
-	if (ret < 0)
-		return ret;
+	if (!(data->ctrl_reg1 & MPL3115_CTRL1_ACTIVE)) {
+		ret = mpl3115_request(data);
+		if (ret < 0)
+			return ret;
+	}
 
 	if (test_bit(0, indio_dev->active_scan_mask)) {
 		ret = i2c_smbus_read_i2c_block_data(data->client,

@@ -234,10 +262,145 @@ static const struct iio_chan_spec mpl3115_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(2),
 };
 
+static irqreturn_t mpl3115_interrupt_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct mpl3115_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(data->client, MPL3115_INT_SOURCE);
+	if (ret < 0)
+		return IRQ_HANDLED;
+
+	if (!(ret & MPL3115_INT_SRC_DRDY))
+		return IRQ_NONE;
+
+	iio_trigger_poll_nested(data->drdy_trig);
+
+	return IRQ_HANDLED;
+}
+
+static int mpl3115_config_interrupt(struct mpl3115_data *data,
+				    u8 ctrl_reg1, u8 ctrl_reg4)
+{
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
+					ctrl_reg1);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG4,
+					ctrl_reg4);
+	if (ret < 0)
+		goto reg1_cleanup;
+
+	data->ctrl_reg1 = ctrl_reg1;
+
+	return 0;
+
+reg1_cleanup:
+	i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
+				  data->ctrl_reg1);
+	return ret;
+}
+
+static int mpl3115_set_trigger_state(struct iio_trigger *trig, bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct mpl3115_data *data = iio_priv(indio_dev);
+	u8 ctrl_reg1 = data->ctrl_reg1;
+	u8 ctrl_reg4 = state ? MPL3115_CTRL4_INT_EN_DRDY : 0;
+
+	if (state)
+		ctrl_reg1 |= MPL3115_CTRL1_ACTIVE;
+	else
+		ctrl_reg1 &= ~MPL3115_CTRL1_ACTIVE;
+
+	guard(mutex)(&data->lock);
+
+	return mpl3115_config_interrupt(data, ctrl_reg1, ctrl_reg4);
+}
+
+static const struct iio_trigger_ops mpl3115_trigger_ops = {
+	.set_trigger_state = mpl3115_set_trigger_state,
+};
+
 static const struct iio_info mpl3115_info = {
 	.read_raw = &mpl3115_read_raw,
 };
 
+static int mpl3115_trigger_probe(struct mpl3115_data *data,
+				 struct iio_dev *indio_dev)
+{
+	struct fwnode_handle *fwnode = dev_fwnode(&data->client->dev);
+	int ret, irq, irq_type, irq_pin = MPL3115_IRQ_INT1;
+
+	irq = fwnode_irq_get_byname(fwnode, "INT1");
+	if (irq < 0) {
+		irq = fwnode_irq_get_byname(fwnode, "INT2");
+		if (irq < 0)
+			return 0;
+
+		irq_pin = MPL3115_IRQ_INT2;
+	}
+
+	irq_type = irq_get_trigger_type(irq);
+	if (irq_type != IRQF_TRIGGER_RISING && irq_type != IRQF_TRIGGER_FALLING)
+		return -EINVAL;
+
+	ret = i2c_smbus_write_byte_data(data->client, MPL3115_PT_DATA_CFG,
+					MPL3115_PT_DATA_EVENT_ALL);
+	if (ret < 0)
+		return ret;
+
+	if (irq_pin == MPL3115_IRQ_INT1) {
+		ret = i2c_smbus_write_byte_data(data->client,
+						MPL3115_CTRL_REG5,
+						MPL3115_CTRL5_INT_CFG_DRDY);
+		if (ret)
+			return ret;
+
+		if (irq_type == IRQF_TRIGGER_RISING) {
+			ret = i2c_smbus_write_byte_data(data->client,
+							MPL3115_CTRL_REG3,
+							MPL3115_CTRL3_IPOL1);
+			if (ret)
+				return ret;
+		}
+	} else if (irq_type == IRQF_TRIGGER_RISING) {
+		ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG3,
+						MPL3115_CTRL3_IPOL2);
+		if (ret)
+			return ret;
+	}
+
+	data->drdy_trig = devm_iio_trigger_alloc(&data->client->dev,
+						 "%s-dev%d",
+						 indio_dev->name,
+						 iio_device_id(indio_dev));
+	if (!data->drdy_trig)
+		return -ENOMEM;
+
+	data->drdy_trig->ops = &mpl3115_trigger_ops;
+	iio_trigger_set_drvdata(data->drdy_trig, indio_dev);
+
+	ret = devm_request_threaded_irq(&data->client->dev, irq, NULL,
+					mpl3115_interrupt_handler,
+					IRQF_ONESHOT,
+					"mpl3115_irq", indio_dev);
+	if (ret)
+		return ret;
+
+	ret = devm_iio_trigger_register(&data->client->dev, data->drdy_trig);
+	if (ret)
+		return ret;
+
+	indio_dev->trig = iio_trigger_get(data->drdy_trig);
+
+	return 0;
+}
+
 static int mpl3115_probe(struct i2c_client *client)
 {
 	const struct i2c_device_id *id = i2c_client_get_device_id(client);

@@ -277,6 +440,10 @@ static int mpl3115_probe(struct i2c_client *client)
 	if (ret < 0)
 		return ret;
 
+	ret = mpl3115_trigger_probe(data, indio_dev);
+	if (ret)
+		return ret;
+
 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
 		mpl3115_trigger_handler, NULL);
 	if (ret < 0)

index e1b2c9f2bb43..c212dfdf59ff 100644
@@ -10,6 +10,7 @@
  * user offset correction, raw mode
  */
 
+#include <linux/bitfield.h>
 #include <linux/cleanup.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>

@@ -30,6 +31,7 @@
 #define MPL3115_INT_SOURCE 0x12
 #define MPL3115_PT_DATA_CFG 0x13
 #define MPL3115_CTRL_REG1 0x26
+#define MPL3115_CTRL_REG2 0x27
 #define MPL3115_CTRL_REG3 0x28
 #define MPL3115_CTRL_REG4 0x29
 #define MPL3115_CTRL_REG5 0x2a

@@ -48,6 +50,8 @@
 #define MPL3115_CTRL1_ACTIVE BIT(0) /* continuous measurement */
 #define MPL3115_CTRL1_OS_258MS GENMASK(5, 4) /* 64x oversampling */
 
+#define MPL3115_CTRL2_ST GENMASK(3, 0)
+
 #define MPL3115_CTRL3_IPOL1 BIT(5)
 #define MPL3115_CTRL3_IPOL2 BIT(1)
 

@@ -55,6 +59,25 @@
 
 #define MPL3115_CTRL5_INT_CFG_DRDY BIT(7)
 
+static const unsigned int mpl3115_samp_freq_table[][2] = {
+	{ 1,      0 },
+	{ 0, 500000 },
+	{ 0, 250000 },
+	{ 0, 125000 },
+	{ 0,  62500 },
+	{ 0,  31250 },
+	{ 0,  15625 },
+	{ 0,   7812 },
+	{ 0,   3906 },
+	{ 0,   1953 },
+	{ 0,    976 },
+	{ 0,    488 },
+	{ 0,    244 },
+	{ 0,    122 },
+	{ 0,     61 },
+	{ 0,     30 },
+};
+
 struct mpl3115_data {
 	struct i2c_client *client;
 	struct iio_trigger *drdy_trig;

@@ -170,10 +193,61 @@ static int mpl3115_read_raw(struct iio_dev *indio_dev,
 		default:
 			return -EINVAL;
 		}
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = i2c_smbus_read_byte_data(data->client, MPL3115_CTRL_REG2);
+		if (ret < 0)
+			return ret;
+
+		ret = FIELD_GET(MPL3115_CTRL2_ST, ret);
+
+		*val = mpl3115_samp_freq_table[ret][0];
+		*val2 = mpl3115_samp_freq_table[ret][1];
+		return IIO_VAL_INT_PLUS_MICRO;
 	}
 	return -EINVAL;
 }
 
+static int mpl3115_read_avail(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      const int **vals, int *type, int *length,
+			      long mask)
+{
+	if (mask != IIO_CHAN_INFO_SAMP_FREQ)
+		return -EINVAL;
+
+	*type = IIO_VAL_INT_PLUS_MICRO;
+	*length = ARRAY_SIZE(mpl3115_samp_freq_table) * 2;
+	*vals = (int *)mpl3115_samp_freq_table;
+	return IIO_AVAIL_LIST;
+}
+
+static int mpl3115_write_raw(struct iio_dev *indio_dev,
+			     const struct iio_chan_spec *chan,
+			     int val, int val2, long mask)
+{
+	struct mpl3115_data *data = iio_priv(indio_dev);
+	int i, ret;
+
+	if (mask != IIO_CHAN_INFO_SAMP_FREQ)
+		return -EINVAL;
+
+	for (i = 0; i < ARRAY_SIZE(mpl3115_samp_freq_table); i++)
+		if (val == mpl3115_samp_freq_table[i][0] &&
+		    val2 == mpl3115_samp_freq_table[i][1])
+			break;
+
+	if (i == ARRAY_SIZE(mpl3115_samp_freq_table))
+		return -EINVAL;
+
+	if (!iio_device_claim_direct(indio_dev))
+		return -EBUSY;
+
+	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG2,
+					FIELD_PREP(MPL3115_CTRL2_ST, i));
+	iio_device_release_direct(indio_dev);
+	return ret;
+}
+
 static int mpl3115_fill_trig_buffer(struct iio_dev *indio_dev, u8 *buffer)
 {
 	struct mpl3115_data *data = iio_priv(indio_dev);

@@ -237,6 +311,9 @@ static const struct iio_chan_spec mpl3115_channels[] = {
 		.type = IIO_PRESSURE,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+		.info_mask_shared_by_all_available =
+			BIT(IIO_CHAN_INFO_SAMP_FREQ),
 		.scan_index = 0,
 		.scan_type = {
 			.sign = 'u',

@@ -250,6 +327,9 @@ static const struct iio_chan_spec mpl3115_channels[] = {
 		.type = IIO_TEMP,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+		.info_mask_shared_by_all_available =
+			BIT(IIO_CHAN_INFO_SAMP_FREQ),
 		.scan_index = 1,
 		.scan_type = {
 			.sign = 's',

@@ -328,6 +408,8 @@ static const struct iio_trigger_ops mpl3115_trigger_ops = {
 
 static const struct iio_info mpl3115_info = {
 	.read_raw = &mpl3115_read_raw,
+	.read_avail = &mpl3115_read_avail,
+	.write_raw = &mpl3115_write_raw,
 };
 
 static int mpl3115_trigger_probe(struct mpl3115_data *data,