[PATCH v2] iio: humidity: hdc100x: add triggered buffer support for HDC100X
From: Alison Schofield
Date: Fri Jul 22 2016 - 01:32:06 EST
Triggered buffer support uses the HDC100X's dual acquisition mode
to read both humidity and temperature in one shot.
Signed-off-by: Alison Schofield <amsfield22@xxxxxxxxx>
Cc: Daniel Baluta <daniel.baluta@xxxxxxxxx>
---
Changes in v2:
Thanks for the review Peter
- switched endianness from IIO_CPU to IIO_BE
- use only one buffer in the handler
- simplify selection of temp &/or humidity to push to buffer
drivers/iio/humidity/Kconfig | 2 +
drivers/iio/humidity/hdc100x.c | 135 +++++++++++++++++++++++++++++++++++++++--
2 files changed, 131 insertions(+), 6 deletions(-)
diff --git a/drivers/iio/humidity/Kconfig b/drivers/iio/humidity/Kconfig
index 738a86d..4883ce1 100644
--- a/drivers/iio/humidity/Kconfig
+++ b/drivers/iio/humidity/Kconfig
@@ -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.
diff --git a/drivers/iio/humidity/hdc100x.c b/drivers/iio/humidity/hdc100x.c
index a03832a..9f41bb5 100644
--- a/drivers/iio/humidity/hdc100x.c
+++ b/drivers/iio/humidity/hdc100x.c
@@ -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;
@@ -87,20 +93,36 @@ static const struct iio_chan_spec hdc100x_channels[] = {
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_INT_TIME) |
BIT(IIO_CHAN_INFO_OFFSET),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 's',
+ .realbits = 16,
+ .storagebits = 16,
+ .endianness = IIO_BE,
+ },
},
{
.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_BE,
+ },
},
{
.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 +284,80 @@ 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,
+};
+
+static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct hdc100x_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+ int delay = data->adc_int_us[0] + data->adc_int_us[1];
+ int ret;
+ s16 buf[8]; /* 2x s16 + padding + 8 byte timestamp */
+
+ /* 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, (u8 *)buf, 4);
+ if (ret < 0) {
+ dev_err(&client->dev, "cannot read sensor data\n");
+ goto err;
+ }
+ /* overwrite unwanted temp data with humid data */
+ if (!test_bit(0, indio_dev->active_scan_mask))
+ buf[0] = buf[1];
+
+ 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 const struct iio_info hdc100x_info = {
.read_raw = hdc100x_read_raw,
.write_raw = hdc100x_write_raw,
@@ -271,9 +370,10 @@ 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 +396,30 @@ 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 +433,7 @@ static struct i2c_driver hdc100x_driver = {
.name = "hdc100x",
},
.probe = hdc100x_probe,
+ .remove = hdc100x_remove,
.id_table = hdc100x_id,
};
module_i2c_driver(hdc100x_driver);
--
2.1.4