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.
...
> +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
