[PATCH v3 0/2] Add support for Aosong AM2315 relative humidity and ambient temperature sensor

[PATCH v3 0/2] Add support for Aosong AM2315 relative humidity and ambient temperature sensor

[Tiberiu Breana]

This patch set adds basic support for the Aosong AM2315 relative
humidity and ambient temperature sensor.

Patch 1 adds basic support, raw readings and ACPI detection.
Patch 2 adds triggered buffer support.
---
v3 change log:

patch 1/2:
- addressed Peter's comments
- added a mutex for the read_data sequence
- added the am2315_sensor_data struct to better abstract data acquisition

patch 2/2:
no changes
---
v2 change log:

patch 1/2:
- moved driver from iio/temperature to iio/humidity
- addressed Jonathan's comments
- fixed scale to export values in millipercent (humidity) and
  millidegrees (temperature)

patch 2/2:
no changes
---
Tiberiu Breana (2):
  iio: humidity: Add support for AM2315
  iio: humidity: Add triggered buffer support for AM2315

 drivers/iio/humidity/Kconfig  |  10 ++
 drivers/iio/humidity/Makefile |   1 +
 drivers/iio/humidity/am2315.c | 303 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 314 insertions(+)
 create mode 100644 drivers/iio/humidity/am2315.c

-- 
1.9.1

[PATCH v3 1/2] iio: humidity: Add support for AM2315

[Tiberiu Breana]

Add basic support for the Aosong AM2315 relative humidity
and ambient temperature sensor.
Includes support for raw readings and ACPI detection.

Datasheet:
http://www.aosong.com/asp_bin/Products/en/AM2315.pdf

Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
---
 drivers/iio/humidity/Kconfig  |  10 ++
 drivers/iio/humidity/Makefile |   1 +
 drivers/iio/humidity/am2315.c | 228 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 239 insertions(+)
 create mode 100644 drivers/iio/humidity/am2315.c

diff --git a/drivers/iio/humidity/Kconfig b/drivers/iio/humidity/Kconfig
index 866dda1..738a86d 100644
--- a/drivers/iio/humidity/Kconfig
+++ b/drivers/iio/humidity/Kconfig
@@ -3,6 +3,16 @@
 #
 menu "Humidity sensors"
 
+config AM2315
+    tristate "Aosong AM2315 relative humidity and temperature sensor"
+    depends on I2C
+    help
+      If you say yes here you get support for the Aosong AM2315
+      relative humidity and ambient temperature sensor.
+
+      This driver can also be built as a module. If so, the module will
+      be called am2315.
+
 config DHT11
 	tristate "DHT11 (and compatible sensors) driver"
 	depends on GPIOLIB || COMPILE_TEST
diff --git a/drivers/iio/humidity/Makefile b/drivers/iio/humidity/Makefile
index c9f089a..4a73442 100644
--- a/drivers/iio/humidity/Makefile
+++ b/drivers/iio/humidity/Makefile
@@ -2,6 +2,7 @@
 # Makefile for IIO humidity sensor drivers
 #
 
+obj-$(CONFIG_AM2315) += am2315.o
 obj-$(CONFIG_DHT11) += dht11.o
 obj-$(CONFIG_HDC100X) += hdc100x.o
 obj-$(CONFIG_HTU21) += htu21.o
diff --git a/drivers/iio/humidity/am2315.c b/drivers/iio/humidity/am2315.c
new file mode 100644
index 0000000..d392fc8
--- /dev/null
+++ b/drivers/iio/humidity/am2315.c
@@ -0,0 +1,228 @@
+/**
+ * Aosong AM2315 relative humidity and temperature
+ *
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * 7-bit I2C address: 0x5C.
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define AM2315_REG_HUM_MSB			0x00
+#define AM2315_REG_HUM_LSB			0x01
+#define AM2315_REG_TEMP_MSB			0x02
+#define AM2315_REG_TEMP_LSB			0x03
+
+#define AM2315_FUNCTION_READ			0x03
+#define AM2315_HUM_OFFSET			2
+#define AM2315_TEMP_OFFSET			4
+
+#define AM2315_DRIVER_NAME			"am2315"
+
+struct am2315_data {
+	struct i2c_client *client;
+	struct mutex lock;
+};
+
+struct am2315_sensor_data {
+	s16 hum_data;
+	s16 temp_data;
+};
+
+static const struct iio_chan_spec am2315_channels[] = {
+	{
+		.type = IIO_HUMIDITYRELATIVE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE)
+	},
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE)
+	},
+};
+
+/* CRC calculation algorithm, as specified in the datasheet (page 13). */
+static u16 am2315_crc(u8 *data, u8 nr_bytes)
+{
+	int i;
+	u16 crc = 0xffff;
+
+	while (nr_bytes--) {
+		crc ^= *data++;
+		for (i = 0; i < 8; i++) {
+			if (crc & 0x01) {
+				crc >>= 1;
+				crc ^= 0xA001;
+			} else {
+				crc >>= 1;
+			}
+		}
+	}
+
+	return crc;
+}
+
+/* Simple function that sends a few bytes to the device to wake it up. */
+static void am2315_ping(struct i2c_client *client)
+{
+	i2c_smbus_read_byte_data(client, AM2315_REG_HUM_MSB);
+}
+
+static int am2315_read_data(struct am2315_data *data,
+			    struct am2315_sensor_data *sensor_data)
+{
+	int ret;
+	/* tx_buf format: <function code> <start addr> <nr of regs to read> */
+	u8 tx_buf[3] = { AM2315_FUNCTION_READ, AM2315_REG_HUM_MSB, 4 };
+	/*
+	 * rx_buf format:
+	 * <function code> <number of registers read>
+	 * <humidity MSB> <humidity LSB> <temp MSB> <temp LSB>
+	 * <CRC LSB> <CRC MSB>
+	 */
+	u8 rx_buf[8];
+	u16 crc;
+
+	/* First wake up the device. */
+	am2315_ping(data->client);
+
+	mutex_lock(&data->lock);
+	ret = i2c_master_send(data->client, tx_buf, sizeof(tx_buf));
+	if (ret < 0) {
+		dev_err(&data->client->dev, "failed to send read request\n");
+		goto exit_unlock;
+	}
+	/* Wait 2-3 ms, then read back the data sent by the device. */
+	usleep_range(2000, 3000);
+	/* Do a bulk data read, then pick out what we need. */
+	ret = i2c_master_recv(data->client, rx_buf, sizeof(rx_buf));
+	if (ret < 0) {
+		dev_err(&data->client->dev, "failed to read sensor data\n");
+		goto exit_unlock;
+	}
+	mutex_unlock(&data->lock);
+	/*
+	 * Do a CRC check on the data and compare it to the value
+	 * calculated by the device.
+	 */
+	crc = am2315_crc(rx_buf, sizeof(rx_buf) - 2);
+	if ((crc & 0xff) != rx_buf[6] || (crc >> 8) != rx_buf[7]) {
+		dev_err(&data->client->dev, "failed to verify sensor data\n");
+		return -EIO;
+	}
+
+	sensor_data->hum_data = (rx_buf[AM2315_HUM_OFFSET] << 8) |
+				 rx_buf[AM2315_HUM_OFFSET + 1];
+	sensor_data->temp_data = (rx_buf[AM2315_TEMP_OFFSET] << 8) |
+				  rx_buf[AM2315_TEMP_OFFSET + 1];
+
+	return ret;
+
+exit_unlock:
+	mutex_unlock(&data->lock);
+	return ret;
+}
+
+static int am2315_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long mask)
+{
+	int ret;
+	struct am2315_sensor_data sensor_data;
+	struct am2315_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = am2315_read_data(data, &sensor_data);
+		if (ret < 0)
+			return ret;
+		*val = (chan->type == IIO_HUMIDITYRELATIVE) ?
+				sensor_data.hum_data : sensor_data.temp_data;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 100;
+		return IIO_VAL_INT;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info am2315_info = {
+	.driver_module		= THIS_MODULE,
+	.read_raw		= am2315_read_raw,
+};
+
+static int am2315_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct iio_dev *indio_dev;
+	struct am2315_data *data;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev) {
+		dev_err(&client->dev, "iio allocation failed!\n");
+		return -ENOMEM;
+	}
+
+	data = iio_priv(indio_dev);
+	data->client = client;
+	i2c_set_clientdata(client, indio_dev);
+	mutex_init(&data->lock);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->info = &am2315_info;
+	indio_dev->name = AM2315_DRIVER_NAME;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = am2315_channels;
+	indio_dev->num_channels = ARRAY_SIZE(am2315_channels);
+
+	return iio_device_register(indio_dev);
+}
+
+static int am2315_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+	iio_device_unregister(indio_dev);
+
+	return 0;
+}
+
+static const struct i2c_device_id am2315_i2c_id[] = {
+	{"am2315", 0},
+	{}
+};
+
+static const struct acpi_device_id am2315_acpi_id[] = {
+	{"AOS2315", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(acpi, am2315_acpi_id);
+
+static struct i2c_driver am2315_driver = {
+	.driver = {
+		.name = "am2315",
+		.acpi_match_table = ACPI_PTR(am2315_acpi_id),
+	},
+	.probe =            am2315_probe,
+	.remove =	    am2315_remove,
+	.id_table =         am2315_i2c_id,
+};
+
+module_i2c_driver(am2315_driver);
+
+MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
+MODULE_DESCRIPTION("Aosong AM2315 relative humidity and temperature");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

[PATCH v3 2/2] iio: humidity: Add triggered buffer support for AM2315

[Tiberiu Breana]

Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
---
 drivers/iio/humidity/am2315.c | 81 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 78 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/humidity/am2315.c b/drivers/iio/humidity/am2315.c
index d392fc8..3be6d20 100644
--- a/drivers/iio/humidity/am2315.c
+++ b/drivers/iio/humidity/am2315.c
@@ -15,8 +15,11 @@
 #include <linux/i2c.h>
 #include <linux/kernel.h>
 #include <linux/module.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/triggered_buffer.h>
 
 #define AM2315_REG_HUM_MSB			0x00
 #define AM2315_REG_HUM_LSB			0x01
@@ -26,12 +29,14 @@
 #define AM2315_FUNCTION_READ			0x03
 #define AM2315_HUM_OFFSET			2
 #define AM2315_TEMP_OFFSET			4
+#define AM2315_ALL_CHANNEL_MASK			GENMASK(1, 0)
 
 #define AM2315_DRIVER_NAME			"am2315"
 
 struct am2315_data {
 	struct i2c_client *client;
 	struct mutex lock;
+	s16 buffer[8]; /* 2x16-bit channels + 2x16 padding + 4x16 timestamp */
 };
 
 struct am2315_sensor_data {
@@ -43,13 +48,28 @@ static const struct iio_chan_spec am2315_channels[] = {
 	{
 		.type = IIO_HUMIDITYRELATIVE,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
-				      BIT(IIO_CHAN_INFO_SCALE)
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_CPU,
+		},
 	},
 	{
 		.type = IIO_TEMP,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
-				      BIT(IIO_CHAN_INFO_SCALE)
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = 1,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_CPU,
+		},
 	},
+	IIO_CHAN_SOFT_TIMESTAMP(2),
 };
 
 /* CRC calculation algorithm, as specified in the datasheet (page 13). */
@@ -134,6 +154,44 @@ exit_unlock:
 	return ret;
 }
 
+static irqreturn_t am2315_trigger_handler(int irq, void *p)
+{
+	int i;
+	int ret;
+	int bit;
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct am2315_data *data = iio_priv(indio_dev);
+	struct am2315_sensor_data sensor_data;
+
+	ret = am2315_read_data(data, &sensor_data);
+	if (ret < 0) {
+		mutex_unlock(&data->lock);
+		goto err;
+	}
+
+	mutex_lock(&data->lock);
+	if (*(indio_dev->active_scan_mask) == AM2315_ALL_CHANNEL_MASK) {
+		data->buffer[0] = sensor_data.hum_data;
+		data->buffer[1] = sensor_data.temp_data;
+	} else {
+		i = 0;
+		for_each_set_bit(bit, indio_dev->active_scan_mask,
+				 indio_dev->masklength) {
+			data->buffer[i] = (bit ? sensor_data.temp_data :
+						 sensor_data.hum_data);
+			i++;
+		}
+	}
+	mutex_unlock(&data->lock);
+
+	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+					   pf->timestamp);
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+	return IRQ_HANDLED;
+}
+
 static int am2315_read_raw(struct iio_dev *indio_dev,
 			   struct iio_chan_spec const *chan,
 			   int *val, int *val2, long mask)
@@ -166,6 +224,7 @@ static const struct iio_info am2315_info = {
 static int am2315_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
+	int ret;
 	struct iio_dev *indio_dev;
 	struct am2315_data *data;
 
@@ -187,7 +246,22 @@ static int am2315_probe(struct i2c_client *client,
 	indio_dev->channels = am2315_channels;
 	indio_dev->num_channels = ARRAY_SIZE(am2315_channels);
 
-	return iio_device_register(indio_dev);
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+					 am2315_trigger_handler, NULL);
+	if (ret < 0) {
+		dev_err(&client->dev, "iio triggered buffer setup failed\n");
+		return ret;
+	}
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		goto err_buffer_cleanup;
+
+	return 0;
+
+err_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+	return ret;
 }
 
 static int am2315_remove(struct i2c_client *client)
@@ -195,6 +269,7 @@ static int am2315_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 0;
 }
-- 
1.9.1

Re: [PATCH v3 1/2] iio: humidity: Add support for AM2315

[Jonathan Cameron]

On 18/04/16 15:50, Tiberiu Breana wrote:
> Add basic support for the Aosong AM2315 relative humidity
> and ambient temperature sensor.
> Includes support for raw readings and ACPI detection.
> 
> Datasheet:
> http://www.aosong.com/asp_bin/Products/en/AM2315.pdf
> 
> Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Looks good.

Applied to the togreg branch of iio.git - initially pushed out as testing
for the autobuilders to play with it.

Thanks,

Jonathan
> ---
>  drivers/iio/humidity/Kconfig  |  10 ++
>  drivers/iio/humidity/Makefile |   1 +
>  drivers/iio/humidity/am2315.c | 228 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 239 insertions(+)
>  create mode 100644 drivers/iio/humidity/am2315.c
> 
> diff --git a/drivers/iio/humidity/Kconfig b/drivers/iio/humidity/Kconfig
> index 866dda1..738a86d 100644
> --- a/drivers/iio/humidity/Kconfig
> +++ b/drivers/iio/humidity/Kconfig
> @@ -3,6 +3,16 @@
>  #
>  menu "Humidity sensors"
>  
> +config AM2315
> +    tristate "Aosong AM2315 relative humidity and temperature sensor"
> +    depends on I2C
> +    help
> +      If you say yes here you get support for the Aosong AM2315
> +      relative humidity and ambient temperature sensor.
> +
> +      This driver can also be built as a module. If so, the module will
> +      be called am2315.
> +
>  config DHT11
>  	tristate "DHT11 (and compatible sensors) driver"
>  	depends on GPIOLIB || COMPILE_TEST
> diff --git a/drivers/iio/humidity/Makefile b/drivers/iio/humidity/Makefile
> index c9f089a..4a73442 100644
> --- a/drivers/iio/humidity/Makefile
> +++ b/drivers/iio/humidity/Makefile
> @@ -2,6 +2,7 @@
>  # Makefile for IIO humidity sensor drivers
>  #
>  
> +obj-$(CONFIG_AM2315) += am2315.o
>  obj-$(CONFIG_DHT11) += dht11.o
>  obj-$(CONFIG_HDC100X) += hdc100x.o
>  obj-$(CONFIG_HTU21) += htu21.o
> diff --git a/drivers/iio/humidity/am2315.c b/drivers/iio/humidity/am2315.c
> new file mode 100644
> index 0000000..d392fc8
> --- /dev/null
> +++ b/drivers/iio/humidity/am2315.c
> @@ -0,0 +1,228 @@
> +/**
> + * Aosong AM2315 relative humidity and temperature
> + *
> + * Copyright (c) 2016, Intel Corporation.
> + *
> + * This file is subject to the terms and conditions of version 2 of
> + * the GNU General Public License. See the file COPYING in the main
> + * directory of this archive for more details.
> + *
> + * 7-bit I2C address: 0x5C.
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> +#define AM2315_REG_HUM_MSB			0x00
> +#define AM2315_REG_HUM_LSB			0x01
> +#define AM2315_REG_TEMP_MSB			0x02
> +#define AM2315_REG_TEMP_LSB			0x03
> +
> +#define AM2315_FUNCTION_READ			0x03
> +#define AM2315_HUM_OFFSET			2
> +#define AM2315_TEMP_OFFSET			4
> +
> +#define AM2315_DRIVER_NAME			"am2315"
> +
> +struct am2315_data {
> +	struct i2c_client *client;
> +	struct mutex lock;
> +};
> +
> +struct am2315_sensor_data {
> +	s16 hum_data;
> +	s16 temp_data;
> +};
> +
> +static const struct iio_chan_spec am2315_channels[] = {
> +	{
> +		.type = IIO_HUMIDITYRELATIVE,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE)
> +	},
> +	{
> +		.type = IIO_TEMP,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE)
> +	},
> +};
> +
> +/* CRC calculation algorithm, as specified in the datasheet (page 13). */
> +static u16 am2315_crc(u8 *data, u8 nr_bytes)
> +{
> +	int i;
> +	u16 crc = 0xffff;
> +
> +	while (nr_bytes--) {
> +		crc ^= *data++;
> +		for (i = 0; i < 8; i++) {
> +			if (crc & 0x01) {
> +				crc >>= 1;
> +				crc ^= 0xA001;
> +			} else {
> +				crc >>= 1;
> +			}
> +		}
> +	}
> +
> +	return crc;
> +}
> +
> +/* Simple function that sends a few bytes to the device to wake it up. */
> +static void am2315_ping(struct i2c_client *client)
> +{
> +	i2c_smbus_read_byte_data(client, AM2315_REG_HUM_MSB);
> +}
> +
> +static int am2315_read_data(struct am2315_data *data,
> +			    struct am2315_sensor_data *sensor_data)
> +{
> +	int ret;
> +	/* tx_buf format: <function code> <start addr> <nr of regs to read> */
> +	u8 tx_buf[3] = { AM2315_FUNCTION_READ, AM2315_REG_HUM_MSB, 4 };
> +	/*
> +	 * rx_buf format:
> +	 * <function code> <number of registers read>
> +	 * <humidity MSB> <humidity LSB> <temp MSB> <temp LSB>
> +	 * <CRC LSB> <CRC MSB>
> +	 */
> +	u8 rx_buf[8];
> +	u16 crc;
> +
> +	/* First wake up the device. */
> +	am2315_ping(data->client);
> +
> +	mutex_lock(&data->lock);
> +	ret = i2c_master_send(data->client, tx_buf, sizeof(tx_buf));
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "failed to send read request\n");
> +		goto exit_unlock;
> +	}
> +	/* Wait 2-3 ms, then read back the data sent by the device. */
> +	usleep_range(2000, 3000);
> +	/* Do a bulk data read, then pick out what we need. */
> +	ret = i2c_master_recv(data->client, rx_buf, sizeof(rx_buf));
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "failed to read sensor data\n");
> +		goto exit_unlock;
> +	}
> +	mutex_unlock(&data->lock);
> +	/*
> +	 * Do a CRC check on the data and compare it to the value
> +	 * calculated by the device.
> +	 */
> +	crc = am2315_crc(rx_buf, sizeof(rx_buf) - 2);
> +	if ((crc & 0xff) != rx_buf[6] || (crc >> 8) != rx_buf[7]) {
> +		dev_err(&data->client->dev, "failed to verify sensor data\n");
> +		return -EIO;
> +	}
> +
> +	sensor_data->hum_data = (rx_buf[AM2315_HUM_OFFSET] << 8) |
> +				 rx_buf[AM2315_HUM_OFFSET + 1];
> +	sensor_data->temp_data = (rx_buf[AM2315_TEMP_OFFSET] << 8) |
> +				  rx_buf[AM2315_TEMP_OFFSET + 1];
> +
> +	return ret;
> +
> +exit_unlock:
> +	mutex_unlock(&data->lock);
> +	return ret;
> +}
> +
> +static int am2315_read_raw(struct iio_dev *indio_dev,
> +			   struct iio_chan_spec const *chan,
> +			   int *val, int *val2, long mask)
> +{
> +	int ret;
> +	struct am2315_sensor_data sensor_data;
> +	struct am2315_data *data = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		ret = am2315_read_data(data, &sensor_data);
> +		if (ret < 0)
> +			return ret;
> +		*val = (chan->type == IIO_HUMIDITYRELATIVE) ?
> +				sensor_data.hum_data : sensor_data.temp_data;
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = 100;
> +		return IIO_VAL_INT;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static const struct iio_info am2315_info = {
> +	.driver_module		= THIS_MODULE,
> +	.read_raw		= am2315_read_raw,
> +};
> +
> +static int am2315_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	struct iio_dev *indio_dev;
> +	struct am2315_data *data;
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> +	if (!indio_dev) {
> +		dev_err(&client->dev, "iio allocation failed!\n");
> +		return -ENOMEM;
> +	}
> +
> +	data = iio_priv(indio_dev);
> +	data->client = client;
> +	i2c_set_clientdata(client, indio_dev);
> +	mutex_init(&data->lock);
> +
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->info = &am2315_info;
> +	indio_dev->name = AM2315_DRIVER_NAME;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = am2315_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(am2315_channels);
> +
> +	return iio_device_register(indio_dev);
> +}
> +
> +static int am2315_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id am2315_i2c_id[] = {
> +	{"am2315", 0},
> +	{}
> +};
> +
> +static const struct acpi_device_id am2315_acpi_id[] = {
> +	{"AOS2315", 0},
> +	{}
> +};
> +
> +MODULE_DEVICE_TABLE(acpi, am2315_acpi_id);
> +
> +static struct i2c_driver am2315_driver = {
> +	.driver = {
> +		.name = "am2315",
> +		.acpi_match_table = ACPI_PTR(am2315_acpi_id),
> +	},
> +	.probe =            am2315_probe,
> +	.remove =	    am2315_remove,
> +	.id_table =         am2315_i2c_id,
> +};
> +
> +module_i2c_driver(am2315_driver);
> +
> +MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
> +MODULE_DESCRIPTION("Aosong AM2315 relative humidity and temperature");
> +MODULE_LICENSE("GPL v2");
> 

Re: [PATCH v3 2/2] iio: humidity: Add triggered buffer support for AM2315

[Jonathan Cameron]

On 18/04/16 15:50, Tiberiu Breana wrote:
> Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Applied, thanks,

Jonathan
> ---
>  drivers/iio/humidity/am2315.c | 81 +++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 78 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/humidity/am2315.c b/drivers/iio/humidity/am2315.c
> index d392fc8..3be6d20 100644
> --- a/drivers/iio/humidity/am2315.c
> +++ b/drivers/iio/humidity/am2315.c
> @@ -15,8 +15,11 @@
>  #include <linux/i2c.h>
>  #include <linux/kernel.h>
>  #include <linux/module.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/triggered_buffer.h>
>  
>  #define AM2315_REG_HUM_MSB			0x00
>  #define AM2315_REG_HUM_LSB			0x01
> @@ -26,12 +29,14 @@
>  #define AM2315_FUNCTION_READ			0x03
>  #define AM2315_HUM_OFFSET			2
>  #define AM2315_TEMP_OFFSET			4
> +#define AM2315_ALL_CHANNEL_MASK			GENMASK(1, 0)
>  
>  #define AM2315_DRIVER_NAME			"am2315"
>  
>  struct am2315_data {
>  	struct i2c_client *client;
>  	struct mutex lock;
> +	s16 buffer[8]; /* 2x16-bit channels + 2x16 padding + 4x16 timestamp */
>  };
>  
>  struct am2315_sensor_data {
> @@ -43,13 +48,28 @@ static const struct iio_chan_spec am2315_channels[] = {
>  	{
>  		.type = IIO_HUMIDITYRELATIVE,
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> -				      BIT(IIO_CHAN_INFO_SCALE)
> +				      BIT(IIO_CHAN_INFO_SCALE),
> +		.scan_index = 0,
> +		.scan_type = {
> +			.sign = 's',
> +			.realbits = 16,
> +			.storagebits = 16,
> +			.endianness = IIO_CPU,
> +		},
>  	},
>  	{
>  		.type = IIO_TEMP,
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> -				      BIT(IIO_CHAN_INFO_SCALE)
> +				      BIT(IIO_CHAN_INFO_SCALE),
> +		.scan_index = 1,
> +		.scan_type = {
> +			.sign = 's',
> +			.realbits = 16,
> +			.storagebits = 16,
> +			.endianness = IIO_CPU,
> +		},
>  	},
> +	IIO_CHAN_SOFT_TIMESTAMP(2),
>  };
>  
>  /* CRC calculation algorithm, as specified in the datasheet (page 13). */
> @@ -134,6 +154,44 @@ exit_unlock:
>  	return ret;
>  }
>  
> +static irqreturn_t am2315_trigger_handler(int irq, void *p)
> +{
> +	int i;
> +	int ret;
> +	int bit;
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct am2315_data *data = iio_priv(indio_dev);
> +	struct am2315_sensor_data sensor_data;
> +
> +	ret = am2315_read_data(data, &sensor_data);
> +	if (ret < 0) {
> +		mutex_unlock(&data->lock);
> +		goto err;
> +	}
> +
> +	mutex_lock(&data->lock);
> +	if (*(indio_dev->active_scan_mask) == AM2315_ALL_CHANNEL_MASK) {
> +		data->buffer[0] = sensor_data.hum_data;
> +		data->buffer[1] = sensor_data.temp_data;
> +	} else {
> +		i = 0;
> +		for_each_set_bit(bit, indio_dev->active_scan_mask,
> +				 indio_dev->masklength) {
> +			data->buffer[i] = (bit ? sensor_data.temp_data :
> +						 sensor_data.hum_data);
> +			i++;
> +		}
> +	}
> +	mutex_unlock(&data->lock);
> +
> +	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
> +					   pf->timestamp);
> +err:
> +	iio_trigger_notify_done(indio_dev->trig);
> +	return IRQ_HANDLED;
> +}
> +
>  static int am2315_read_raw(struct iio_dev *indio_dev,
>  			   struct iio_chan_spec const *chan,
>  			   int *val, int *val2, long mask)
> @@ -166,6 +224,7 @@ static const struct iio_info am2315_info = {
>  static int am2315_probe(struct i2c_client *client,
>  			const struct i2c_device_id *id)
>  {
> +	int ret;
>  	struct iio_dev *indio_dev;
>  	struct am2315_data *data;
>  
> @@ -187,7 +246,22 @@ static int am2315_probe(struct i2c_client *client,
>  	indio_dev->channels = am2315_channels;
>  	indio_dev->num_channels = ARRAY_SIZE(am2315_channels);
>  
> -	return iio_device_register(indio_dev);
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> +					 am2315_trigger_handler, NULL);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "iio triggered buffer setup failed\n");
> +		return ret;
> +	}
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0)
> +		goto err_buffer_cleanup;
> +
> +	return 0;
> +
> +err_buffer_cleanup:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +	return ret;
>  }
>  
>  static int am2315_remove(struct i2c_client *client)
> @@ -195,6 +269,7 @@ static int am2315_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 0;
>  }
>