On Sun, 10 Oct 2021 16:59:19 +0100
Jonathan Cameron [off-list ref] wrote:

On Fri,  8 Oct 2021 12:17:02 +0200
Roan van Dijk [off-list ref] wrote:

quoted

This series adds support for the Sensirion SCD4x sensor.

The driver supports continuous reads of temperature, relative humdity and CO2
concentration. There is an interval of 5 seconds between readings. During
this interval the drivers checks if the sensor has new data available.

The driver is based on the scd30 driver. However, The scd4x has become too
different to just expand the scd30 driver. I made a new driver instead of
expanding the scd30 driver. I hope I made the right choice by doing so?  

Applied to the togreg branch of iio.git with the issues Randy mentioned tidied
up. Pushed out as testing for 0-day to see if it can find anything we missed

And indeed - I missed a bunch of places where explicit __be16 types should have
been used.

I've applied the following fixup, shout if it's wrong.

diff --git a/drivers/iio/chemical/scd4x.c b/drivers/iio/chemical/scd4x.c
index 09b34201c42b..ebebcb117ba2 100644
--- a/drivers/iio/chemical/scd4x.c
+++ b/drivers/iio/chemical/scd4x.c

@@ -263,7 +263,7 @@ static int scd4x_write_and_fetch(struct scd4x_state *state, enum scd4x_cmd cmd,
 static int scd4x_read_meas(struct scd4x_state *state, uint16_t *meas)
 {
 	int i, ret;
-	uint16_t buf[3];
+	__be16 buf[3];
 
 	ret = scd4x_read(state, CMD_READ_MEAS, buf, sizeof(buf));
 	if (ret)

@@ -282,12 +282,13 @@ static int scd4x_wait_meas_poll(struct scd4x_state *state)
 	int ret;
 
 	do {
+		__be16 bval;
 		uint16_t val;
 
-		ret = scd4x_read(state, CMD_GET_DATA_READY, &val, sizeof(val));
+		ret = scd4x_read(state, CMD_GET_DATA_READY, &bval, sizeof(bval));
 		if (ret)
 			return -EIO;
-		val = be16_to_cpu(val);
+		val = be16_to_cpu(bval);
 
 		/* new measurement available */
 		if (val & 0x7FF)

@@ -333,7 +334,7 @@ static int scd4x_read_raw(struct iio_dev *indio_dev,
 {
 	struct scd4x_state *state = iio_priv(indio_dev);
 	int ret;
-	uint16_t tmp;
+	__be16 tmp;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:

@@ -405,17 +406,18 @@ static ssize_t calibration_auto_enable_show(struct device *dev,
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct scd4x_state *state = iio_priv(indio_dev);
 	int ret;
-	uint16_t val;
+	__be16 bval;
+	u16 val;
 
 	mutex_lock(&state->lock);
-	ret = scd4x_read(state, CMD_GET_ASC, &val, sizeof(val));
+	ret = scd4x_read(state, CMD_GET_ASC, &bval, sizeof(bval));
 	mutex_unlock(&state->lock);
 	if (ret) {
 		dev_err(dev, "failed to read automatic calibration");
 		return ret;
 	}
 
-	val = (be16_to_cpu(val) & SCD4X_READY_MASK) ? 1 : 0;
+	val = (be16_to_cpu(bval) & SCD4X_READY_MASK) ? 1 : 0;
 
 	return sprintf(buf, "%d\n", val);
 }

Thanks,

Jonathan

quoted

Changes since v5:
scd4x.c:
  - Fix bug in trigger_handler

Changes since v4:
scd4x.c:
  - Minor fixes in documentation
  - Reorder trigger_handler so memcpy is not needed anymore
Documentation:
  - Change information about the KernelVersion for the 
    calibration_forced_value_available

Changes since v3:
scd4x.c
  - Change read and write_and_fetch function parameter. CRC byte is now
    hidden inside the function.
  - Fix minor style issues
  - Add calibration_forced_value_available attribute to the driver
  - Remove including BUFFER_TRIGGERED
  - Change calibbias to raw ADC readings rather than converting it to
    milli degrees C.
Documentation:
  - Change description of driver attributes
  - Add calibration_forced_value_available documentation

Changes since v2:
scd4x.c:
  - Change boolean operations
  - Document scope of lock
  - Remove device *dev from struct
  - Add goto block for errror handling
  - Add function to read value per channel in read_raw
  - Fix bug with lock in error paths
  - Remove conversion of humidity and temperature values
  - Add scale and offset to temperature channel
  - Add scale to humidity channel
  - Move memset out of locked section
  - Remove unused irq functions
  - Move device register at end of probe function
Documentation:
  - Copy content of sysfs-bus-iio-scd30 to sysfs-bus-iio
  - Remove Documentation/ABI/testing/sysfs-bus-iio-scd30

Changes since v1:
dt-bindings:
  - Separated compatible string for each sensor type
scd4x.c:
  - Changed probe, resume and suspend functions to static
  - Added SIMPLE_DEV_PM_OPS function call for power management
    operations.

Roan van Dijk (4):
  dt-bindings: iio: chemical: sensirion,scd4x: Add yaml description
  MAINTAINERS: Add myself as maintainer of the scd4x driver
  drivers: iio: chemical: Add support for Sensirion SCD4x CO2 sensor
  iio: documentation: Document scd4x calibration use

 Documentation/ABI/testing/sysfs-bus-iio       |  41 ++
 Documentation/ABI/testing/sysfs-bus-iio-scd30 |  34 -
 .../iio/chemical/sensirion,scd4x.yaml         |  46 ++
 MAINTAINERS                                   |   6 +
 drivers/iio/chemical/Kconfig                  |  13 +
 drivers/iio/chemical/Makefile                 |   1 +
 drivers/iio/chemical/scd4x.c                  | 689 ++++++++++++++++++
 7 files changed, 796 insertions(+), 34 deletions(-)
 delete mode 100644 Documentation/ABI/testing/sysfs-bus-iio-scd30
 create mode 100644 Documentation/devicetree/bindings/iio/chemical/sensirion,scd4x.yaml
 create mode 100644 drivers/iio/chemical/scd4x.c