[PATCH v2 6/6] iio: pressure: Add triggered buffer support for BMP280 driver

Vasileios Amoiridis
2024-03-13T17:40:26Z

Add a buffer struct that will hold the values of the measurements
and will be pushed to userspace and a buffer_handler function to
read the data and push them.

Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
drivers/iio/pressure/Kconfig | 2 +
drivers/iio/pressure/bmp280-core.c | 61 ++++++++++++++++++++++++++++++
drivers/iio/pressure/bmp280.h | 7 ++++
3 files changed, 70 insertions(+)

diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
index 79adfd059c3a..5145b94b4679 100644
--- a/drivers/iio/pressure/Kconfig
+++ b/drivers/iio/pressure/Kconfig
@@ -31,6 +31,8 @@ config BMP280
select REGMAP
select BMP280_I2C if (I2C)
select BMP280_SPI if (SPI_MASTER)
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
help
Say yes here to build support for Bosch Sensortec BMP180, BMP280, BMP380
and BMP580 pressure and temperature sensors. Also supports the BME280 with
diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index f2cf9bef522c..7c889cda396a 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -40,7 +40,10 @@
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>

+#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>

#include <asm/unaligned.h>

@@ -2188,6 +2191,57 @@ static int bmp085_fetch_eoc_irq(struct device *dev,
return 0;
}

+static irqreturn_t bmp280_buffer_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct bmp280_data *data = iio_priv(indio_dev);
+ int ret, temp;
+
+ /*
+ * data->buf[3] is used to transfer data from the device. Whenever a
+ * pressure or a humidity reading takes place, the data written in the
+ * data->buf[3] overwrites the iio_buf.temperature value. Keep the
+ * temperature value and apply it after the readings.
+ */
+ mutex_lock(&data->lock);
+
+ if (test_bit(BMP280_TEMP, indio_dev->active_scan_mask)) {
+ ret = data->chip_info->read_temp(data);
+ if (ret < 0)
+ goto done;
+
+ temp = ret;
+ }
+
+ if (test_bit(BMP280_PRESS, indio_dev->active_scan_mask)) {
+ ret = data->chip_info->read_press(data);
+ if (ret < 0)
+ goto done;
+
+ data->iio_buf.pressure = ret;
+ data->iio_buf.temperature = temp;
+ }
+
+ if (test_bit(BME280_HUMID, indio_dev->active_scan_mask)) {
+ ret = data->chip_info->read_humid(data);
+ if (ret < 0)
+ goto done;
+
+ data->iio_buf.humidity = ret;
+ data->iio_buf.temperature = temp;
+ }
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &data->iio_buf,
+ iio_get_time_ns(indio_dev));
+
+done:
+ mutex_unlock(&data->lock);
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
static void bmp280_pm_disable(void *data)
{
struct device *dev = data;
@@ -2329,6 +2383,13 @@ int bmp280_common_probe(struct device *dev,
return ret;
}

+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+ iio_pollfunc_store_time,
+ &bmp280_buffer_handler, NULL);
+ if (ret)
+ return dev_err_probe(data->dev, ret,
+ "iio triggered buffer setup failed\n");
+
/* Enable runtime PM */
pm_runtime_get_noresume(dev);
pm_runtime_set_active(dev);
diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
index c8cb7c417dab..b5369dd496ba 100644
--- a/drivers/iio/pressure/bmp280.h
+++ b/drivers/iio/pressure/bmp280.h
@@ -407,6 +407,13 @@ struct bmp280_data {
union {
/* Sensor data buffer */
u8 buf[3];
+ /* Data buffer to push to userspace */
+ struct {
+ s32 temperature;
+ u32 pressure;
+ u32 humidity;
+ s64 timestamp __aligned(8);
+ } iio_buf;
/* Calibration data buffers */
__le16 bmp280_cal_buf[BMP280_CONTIGUOUS_CALIB_REGS / 2];
__be16 bmp180_cal_buf[BMP180_REG_CALIB_COUNT / 2];
--
2.25.1