iio: humidity: hdc100x: add triggered buffer support for HDC100X

Triggered buffer support uses the HDC100X's dual acquisition mode to read both humidity and temperature in one shot.

Signed-off-by Alison Schofield <[email protected]>

Cc Daniel Baluta <[email protected]>

---
 drivers/iio/humidity/Kconfig   |   2 +
 drivers/iio/humidity/hdc100x.c | 144 +++++++++++++++++++++++++++++++++++++++--
 2 files changed, 140 insertions(+), 6 deletions(-)

drivers/iio/humidity/Kconfig +2 -0

index 738a86d..4883ce1 100644
@@ -25,6 +25,8 @@ config DHT11
 config HDC100X
 	tristate "TI HDC100x relative humidity and temperature sensor"
 	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
 	help
 	 Say yes here to build support for the TI HDC100x series of
 	 relative humidity and temperature sensors.

drivers/iio/humidity/hdc100x.c +6 -0

index a03832a..85325d4 100644
@@ -22,13 +22,19 @@
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 
 #define HDC100X_REG_TEMP			0x00
 #define HDC100X_REG_HUMIDITY			0x01
 
 #define HDC100X_REG_CONFIG			0x02
+#define HDC100X_REG_CONFIG_ACQ_MODE		BIT(12)
 #define HDC100X_REG_CONFIG_HEATER_EN		BIT(13)
 
+#define HDC100X_ALL_CHANNEL_MASK		GENMASK(1, 0)
+
 struct hdc100x_data {
 	struct i2c_client *client;
 	struct mutex lock;

drivers/iio/humidity/hdc100x.c +55 -3

+		},
 	},
 	{
 		.type = IIO_HUMIDITYRELATIVE,
 		.address = HDC100X_REG_HUMIDITY,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 			BIT(IIO_CHAN_INFO_SCALE) |
-			BIT(IIO_CHAN_INFO_INT_TIME)
+			BIT(IIO_CHAN_INFO_INT_TIME),
+		.scan_index = 1,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_CPU,
+		},
 	},
 	{
 		.type = IIO_CURRENT,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.extend_name = "heater",
 		.output = 1,
+		.scan_index = -1,
 	},
+	IIO_CHAN_SOFT_TIMESTAMP(3),
 };
 
 static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)

@@ -191,18 +213,21 @@ static int hdc100x_read_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_RAW: {
 		int ret;
 
-		mutex_lock(&data->lock);
 		if (chan->type == IIO_CURRENT) {
 			*val = hdc100x_get_heater_status(data);
 			ret = IIO_VAL_INT;
 		} else {
+			ret = iio_device_claim_direct_mode(indio_dev);
+			if (ret)
+				return ret;
+
 			ret = hdc100x_get_measurement(data, chan);
+			iio_device_release_direct_mode(indio_dev);
 			if (ret >= 0) {
 				*val = ret;
 				ret = IIO_VAL_INT;
 			}
 		}
-		mutex_unlock(&data->lock);
 		return ret;
 	}
 	case IIO_CHAN_INFO_INT_TIME:

@@ -259,6 +284,89 @@ static int hdc100x_write_raw(struct iio_dev *indio_dev,
 	}
 }
 
+static int hdc100x_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct hdc100x_data *data = iio_priv(indio_dev);
+	int ret;
+
+	/* Buffer is enabled. First set ACQ Mode, then attach poll func */
+	mutex_lock(&data->lock);
+	ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE,
+				    HDC100X_REG_CONFIG_ACQ_MODE);
+	mutex_unlock(&data->lock);
+	if (ret)
+		return ret;
+
+	return iio_triggered_buffer_postenable(indio_dev);
+}
+
+static int hdc100x_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct hdc100x_data *data = iio_priv(indio_dev);
+	int ret;
+
+	/* First detach poll func, then reset ACQ mode. OK to disable buffer */
+	ret = iio_triggered_buffer_predisable(indio_dev);
+	if (ret)
+		return ret;
+
+	mutex_lock(&data->lock);
+	ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
+	mutex_unlock(&data->lock);
+	return ret;
+}
+
+static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
+	.preenable   = NULL,
+	.postenable  = hdc100x_buffer_postenable,
+	.predisable  = hdc100x_buffer_predisable,
+	.postdisable = NULL,
+};
+

drivers/iio/humidity/hdc100x.c +10 -0

+
+	/* dual read starts at temp register */
+	ret = i2c_smbus_write_byte(client, HDC100X_REG_TEMP);
+	if (ret < 0) {
+		dev_err(&client->dev, "cannot start measurement\n");
+		goto err;
+	}
+	usleep_range(delay, delay + 1000);
+
+	ret = i2c_master_recv(client, recv_buf, sizeof(recv_buf));

drivers/iio/humidity/hdc100x.c +41 -3

+				 indio_dev->masklength) {
+			push_buf[i] = bit ? (recv_buf[2] << 8 | recv_buf[3])
+					  : (recv_buf[0] << 8 | recv_buf[1]);
+			i++;
+		}
+	}
+	iio_push_to_buffers_with_timestamp(indio_dev, push_buf,
+					   iio_get_time_ns(indio_dev));
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
 static const struct iio_info hdc100x_info = {
 	.read_raw = hdc100x_read_raw,
 	.write_raw = hdc100x_write_raw,

@@ -271,9 +379,10 @@ static int hdc100x_probe(struct i2c_client *client,
 {
 	struct iio_dev *indio_dev;
 	struct hdc100x_data *data;
+	int ret;
 
-	if (!i2c_check_functionality(client->adapter,
-				I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
+				     I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
 		return -EOPNOTSUPP;
 
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));

@@ -296,8 +405,30 @@ static int hdc100x_probe(struct i2c_client *client,
 	/* be sure we are in a known state */
 	hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
 	hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
+	hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+					 hdc100x_trigger_handler,
+					 &hdc_buffer_setup_ops);
+	if (ret < 0) {
+		dev_err(&client->dev, "iio triggered buffer setup failed\n");
+		return ret;
+	}
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		iio_triggered_buffer_cleanup(indio_dev);
+
+	return ret;
+}
+
+static int hdc100x_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
 
-	return devm_iio_device_register(&client->dev, indio_dev);
+	return 0;
 }
 
 static const struct i2c_device_id hdc100x_id[] = {

@@ -311,6 +442,7 @@ static struct i2c_driver hdc100x_driver = {
 		.name	= "hdc100x",
 	},
 	.probe = hdc100x_probe,
+	.remove = hdc100x_remove,
 	.id_table = hdc100x_id,
 };
 module_i2c_driver(hdc100x_driver);