Re: [PATCH v2] iio: chemical: sps30: add support for self cleaning
From: Andreas Brauchli
Date: Fri Dec 28 2018 - 09:48:40 EST
On Sat, 22 Dec 2018 17:23:46 +0000
Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
> On Tue, 18 Dec 2018 21:28:09 +0100
> Tomasz Duszynski <tduszyns@xxxxxxxxx> wrote:
>
> > Self cleaning is especially useful in cases where sensor undergoes
> > frequent power on/off cycles. In such scenarios it is recommended to
> > turn self cleaning at least once per week in order to maintain reliable
> > measurements.
> >
> > Self cleaning is activated by writing 1 to a dedicated attribute.
> > Internal fan accelerates to its maximum speed and keeps spinning
> > for about 10 seconds blowing out accumulated dust.
> >
> > Signed-off-by: Tomasz Duszynski <tduszyns@xxxxxxxxx>
> Applied to the togreg branch of iio.git. I took this today rather than
> leaving it on the list for longer simply because I'm not sure I'll be
> very timely in applying patches.
>
> If anyone has any comments, it'll only be out as testing so we can
> still modify if that make sense for at least the next couple of weeks.
I backported and tested the whole series on a 4.9.53 raspberry pi with an SPS30.
Tested-by: Andreas Brauchli <andreas.brauchli@xxxxxxxxxxxxx>
Cheers,
Andreas
>
> Thanks,
>
> Jonathan
>
> > ---
> > v2:
> > * removed TODO item
> > * sensor cleaning is not measurement related per se so drop in_ prefix
> >
> > Documentation/ABI/testing/sysfs-bus-iio-sps30 | 8 +++++
> > drivers/iio/chemical/sps30.c | 35 ++++++++++++++++++-
> > 2 files changed, 42 insertions(+), 1 deletion(-)
> > create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-sps30
> >
> > diff --git a/Documentation/ABI/testing/sysfs-bus-iio-sps30
> b/Documentation/ABI/testing/sysfs-bus-iio-sps30
> > new file mode 100644
> > index 000000000000..e7ce2c57635e
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/sysfs-bus-iio-sps30
> > @@ -0,0 +1,8 @@
> > +What: /sys/bus/iio/devices/iio:deviceX/start_cleaning
> > +Date: December 2018
> > +KernelVersion: 4.22
> > +Contact: linux-iio@xxxxxxxxxxxxxxx
> > +Description:
> > + Writing 1 starts sensor self cleaning. Internal fan accelerates
> > + to its maximum speed and keeps spinning for about 10 seconds in
> > + order to blow out accumulated dust.
> > diff --git a/drivers/iio/chemical/sps30.c b/drivers/iio/chemical/sps30.c
> > index fa3cd409b90b..f3b4390c8f5c 100644
> > --- a/drivers/iio/chemical/sps30.c
> > +++ b/drivers/iio/chemical/sps30.c
> > @@ -7,7 +7,6 @@
> > * I2C slave address: 0x69
> > *
> > * TODO:
> > - * - support for turning on fan cleaning
> > * - support for reading/setting auto cleaning interval
> > */
> >
> > @@ -37,6 +36,7 @@
> > #define SPS30_READ_DATA_READY_FLAG 0x0202
> > #define SPS30_READ_DATA 0x0300
> > #define SPS30_READ_SERIAL 0xd033
> > +#define SPS30_START_FAN_CLEANING 0x5607
> >
> > enum {
> > PM1,
> > @@ -104,6 +104,7 @@ static int sps30_do_cmd(struct sps30_state *state, u16 cmd, u8 *data, int
> size)
> > break;
> > case SPS30_STOP_MEAS:
> > case SPS30_RESET:
> > + case SPS30_START_FAN_CLEANING:
> > ret = sps30_write_then_read(state, buf, 2, NULL, 0);
> > break;
> > case SPS30_READ_DATA_READY_FLAG:
> > @@ -275,7 +276,39 @@ static int sps30_read_raw(struct iio_dev *indio_dev,
> > return -EINVAL;
> > }
> >
> > +static ssize_t start_cleaning_store(struct device *dev,
> > + struct device_attribute *attr,
> > + const char *buf, size_t len)
> > +{
> > + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> > + struct sps30_state *state = iio_priv(indio_dev);
> > + int val, ret;
> > +
> > + if (kstrtoint(buf, 0, &val) || val != 1)
> > + return -EINVAL;
> > +
> > + mutex_lock(&state->lock);
> > + ret = sps30_do_cmd(state, SPS30_START_FAN_CLEANING, NULL, 0);
> > + mutex_unlock(&state->lock);
> > + if (ret)
> > + return ret;
> > +
> > + return len;
> > +}
> > +
> > +static IIO_DEVICE_ATTR_WO(start_cleaning, 0);
> > +
> > +static struct attribute *sps30_attrs[] = {
> > + &iio_dev_attr_start_cleaning.dev_attr.attr,
> > + NULL
> > +};
> > +
> > +static const struct attribute_group sps30_attr_group = {
> > + .attrs = sps30_attrs,
> > +};
> > +
> > static const struct iio_info sps30_info = {
> > + .attrs = &sps30_attr_group,
> > .read_raw = sps30_read_raw,
> > };
> >
> > --
> > 2.20.1
> >