On Thu, Feb 15, 2024 at 05:43:32PM +0100, Vasileios Amoiridis wrote:
> According to the datasheet of BMP38x and BMP390 devices, in SPI
> operation, the first byte that returns after a read operation is
> garbage and it needs to be dropped and return the rest of the
> bytes.
Thank you for the patch, my comments below.
...
> +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 ret[BMP380_SPI_MAX_REG_COUNT_READ + 1];
> + ssize_t status;
> + u8 buf;
AFAIU this buffer is not DMA-capable.
> + memcpy(&buf, reg, reg_size);
I prefer to see a switch case with cases based on allowed sizes and proper
endianess accessors.
> + buf |= 0x80;
This is done by regmap, no?
> + /*
> + * According to the BMP380, BMP388, BMP390 datasheets, for a basic
> + * read operation, after the write is done, 2 bytes are received and
> + * the first one has to be dropped. The 2nd one is the requested
> + * value.
> + */
> + status = spi_write_then_read(spi, &buf, 1, ret, val_size + 1);
sizeof() ?
> + if (status)
> + return status;
> + memcpy(val, ret + 1, val_size);
As per above.
> + return 0;
> +}
--
With Best Regards,
Andy Shevchenko
