On Mon, 26 Nov 2018 21:48:07 +0100 Tomasz Duszynski <tduszyns@xxxxxxxxx> wrote: > On Sun, Nov 25, 2018 at 04:14:34PM +0530, Himanshu Jha wrote: > > On Sat, Nov 24, 2018 at 11:14:14PM +0100, Tomasz Duszynski wrote: > > > Add support for Sensirion SPS30 particulate matter sensor. > > > > > > Signed-off-by: Tomasz Duszynski <tduszyns@xxxxxxxxx> > > > --- > > > drivers/iio/chemical/Kconfig | 11 ++ > > > drivers/iio/chemical/Makefile | 1 + > > > drivers/iio/chemical/sps30.c | 359 ++++++++++++++++++++++++++++++++++ > > > 3 files changed, 371 insertions(+) > > > create mode 100644 drivers/iio/chemical/sps30.c > > > > [] > > > > > +#define pr_fmt(fmt) "sps30: " fmt > > > > I don't see its usage ? > > > > Hint: checkout how dev_err() is defined. > > > > +#include <linux/crc8.h> > > > +#include <linux/delay.h> > > > +#include <linux/i2c.h> > > > +#include <linux/iio/buffer.h> > > > +#include <linux/iio/iio.h> > > > +#include <linux/iio/sysfs.h> > > > +#include <linux/iio/trigger_consumer.h> > > > +#include <linux/iio/triggered_buffer.h> > > > +#include <linux/module.h> > > > + > > > +#define SPS30_CRC8_POLYNOMIAL 0x31 > > > + > > > +/* SPS30 commands */ > > > +#define SPS30_START_MEAS 0x0010 > > > +#define SPS30_STOP_MEAS 0x0104 > > > +#define SPS30_RESET 0xd304 > > > +#define SPS30_READ_DATA_READY_FLAG 0x0202 > > > +#define SPS30_READ_DATA 0x0300 > > > +#define SPS30_READ_SERIAL 0xD033 > > > > Could you please put a tab and align these macros. > > > > #define SPS30_START_MEAS 0x0010 > > #define SPS30_STOP_MEAS 0x0104 > > > > In my opinion this sort of alignment does not pay off in the long run. > Adding a new definition, a slightly longer one perhaps, can easily break > formatting. > > So I would stay with current one. Personally I agree with you on this one. I don't care enough to say either way though normally! > > > > > > +static int sps30_write_then_read(struct sps30_state *state, u8 *buf, > > > + int buf_size, u8 *data, int data_size) > > > +{ > > > + /* every two received data bytes are checksummed */ > > > + u8 tmp[data_size + data_size / 2]; > > > > No VLAs! > > > > https://lore.kernel.org/lkml/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@xxxxxxxxxxxxxx/ > > > > Looks like -Wvla is some fairly recent addition to KBUILD_CFLAGS. Yeah, that was only after a 'lot' of effort over years to get the number present down to a small number. I wrote plenty of them in the early days of IIO so got a lot of those patches as part of the move to introducing the warning :) Jonathan ...