On Tue, Feb 20, 2024 at 04:09:26PM +0200, Andy Shevchenko wrote:
> On Mon, Feb 19, 2024 at 08:13:59PM +0100, Vasileios Amoiridis wrote:
> > According to the datasheet of BMP38x and BMP390 devices, for an SPI
> > read operation the first byte that is returned needs to be dropped,
> > and the rest of the bytes are the actual data returned from the
> > sensor.
>
> ...
>
> > #include <linux/spi/spi.h>
> > #include <linux/err.h>
> > #include <linux/regmap.h>
> > +#include <linux/bits.h>
>
> I see that it's unsorted, but try to squeeze a new header to the better place
> where more will be kept sorted. With given context, it should go before all
> others, but it might be even better location.
>
> ...
>
So you would suggest a re-ordering of the headers with a reverse
christmas-tree? I don't see it used in the other drivers of the IIO
subsystem but I can do it as well
> > +static int bmp380_regmap_spi_read(void *context, const void *reg,
> > + size_t reg_size, void *val, size_t val_size)
> > +{
> > + struct spi_device *spi = to_spi_device(context);
> > + u8 rx_buf[4];
> > + ssize_t status;
> > +
> > + /*
> > + * Maximum number of consecutive bytes read for a temperature or
> > + * pressure measurement is 3.
> > + */
> > + if (val_size > 3)
> > + return -EINVAL;
> > + /*
> > + * According to the BMP3xx datasheets, for a basic SPI read opertion,
> > + * the first byte needs to be dropped and the rest are the requested
> > + * data.
> > + */
> > + status = spi_write_then_read(spi, reg, 1, rx_buf, val_size + 1);
> > + if (status)
> > + return status;
>
> > + memcpy(val, rx_buf + 1, val_size);
>
> Okay, endianess is defined in the regmap_bus below...
>
> > + return 0;
> > +}
>
> --
> With Best Regards,
> Andy Shevchenko
>
>
