A software trigger such as hrtimer can be used to capture the data
that will be stored in the buffer.
Cc: Daniel Baluta <daniel.baluta@xxxxxxxxx>
Cc: Alison Schofield <amsfield22@xxxxxxxxx>
Signed-off-by: Narcisa Ana Maria Vasile <narcisaanamaria12@xxxxxxxxx>
---
Changes in v2:
- Remove initialization of "shift" field with 0 in structure
- Remove taking the lock inside the trigger handler
- Replace devm_iio_triggered_buffer_setup with the non-devm*
function, in order to safely do the cleanup
- Add cleanup for triggered-buffer, inside remove function
- Put device in idle mode in case of error, in probe function
- Add error message, in case data can't be read, inside trigger handler
drivers/iio/chemical/Kconfig | 2 ++
drivers/iio/chemical/ccs811.c | 76 ++++++++++++++++++++++++++++++++++++++++---
2 files changed, 73 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
index 4d799b5..5cb5be7 100644
--- a/drivers/iio/chemical/Kconfig
+++ b/drivers/iio/chemical/Kconfig
@@ -24,6 +24,8 @@ config ATLAS_PH_SENSOR
config CCS811
tristate "AMS CCS811 VOC sensor"
depends on I2C
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
help
Say Y here to build I2C interface support for the AMS
CCS811 VOC (Volatile Organic Compounds) sensor
diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c
index 8dbb5ed..840a6cb 100644
--- a/drivers/iio/chemical/ccs811.c
+++ b/drivers/iio/chemical/ccs811.c
@@ -21,6 +21,9 @@
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
#include <linux/module.h>
#define CCS811_STATUS 0x00
@@ -76,25 +79,42 @@ struct ccs811_data {
{
.type = IIO_CURRENT,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
- BIT(IIO_CHAN_INFO_SCALE)
+ BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = -1,
}, {
.type = IIO_VOLTAGE,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
- BIT(IIO_CHAN_INFO_SCALE)
+ BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = -1,
}, {
.type = IIO_CONCENTRATION,
.channel2 = IIO_MOD_CO2,
.modified = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_OFFSET) |
- BIT(IIO_CHAN_INFO_SCALE)
+ BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 16,
+ .storagebits = 16,
+ .endianness = IIO_BE,
+ },
}, {
.type = IIO_CONCENTRATION,
.channel2 = IIO_MOD_VOC,
.modified = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
- BIT(IIO_CHAN_INFO_SCALE)
+ BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 1,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 16,
+ .storagebits = 16,
+ .endianness = IIO_BE,
+ },
},
+ IIO_CHAN_SOFT_TIMESTAMP(2),
};
/*
@@ -253,6 +273,31 @@ static int ccs811_read_raw(struct iio_dev *indio_dev,
.driver_module = THIS_MODULE,
};
+static irqreturn_t ccs811_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct ccs811_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+ s16 buf[8]; /* s16 eCO2 + s16 TVOC + padding + 8 byte timestamp */
+ int ret;
+
+ ret = i2c_smbus_read_i2c_block_data(client, CCS811_ALG_RESULT_DATA, 4,
+ (u8 *)&buf);
+ if (ret != 4) {
+ dev_err(&client->dev, "cannot read sensor data\n");
+ goto err;
+ }
+
+ iio_push_to_buffers_with_timestamp(indio_dev, buf,
+ iio_get_time_ns(indio_dev));
+
+err:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
static int ccs811_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -305,7 +350,27 @@ static int ccs811_probe(struct i2c_client *client,
indio_dev->channels = ccs811_channels;
indio_dev->num_channels = ARRAY_SIZE(ccs811_channels);
- return iio_device_register(indio_dev);
+ ret = iio_triggered_buffer_setup(indio_dev, NULL,
+ ccs811_trigger_handler, NULL);
+
+ if (ret < 0) {
+ dev_err(&client->dev, "triggered buffer setup failed\n");
+ goto err_poweroff;
+ }
+
+ ret = iio_device_register(indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev, "unable to register iio device\n");
+ goto err_buffer_cleanup;
+ }
+ return 0;
+
+err_buffer_cleanup:
+ iio_triggered_buffer_cleanup(indio_dev);
+err_poweroff:
+ i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE, CCS811_MODE_IDLE);
+
+ return ret;
}
static int ccs811_remove(struct i2c_client *client)
@@ -313,6 +378,7 @@ static int ccs811_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 i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE,
CCS811_MODE_IDLE);
--
1.9.1
--
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