On 01/29/2014 05:53 PM, Peter Meerwald wrote: > Hello, > >> Three months ago Lars-Peter revised description of device driver[1]. > > me, not Lars-Peter > I'm really sorry, my mistake. >> Correctly, device's sensitivity is 0.3 uT/LSB typ and One micro tesla equal 0.01 gauss[2]. >> So I have fixed calculation formula,And then add RAW_TO_GAUSS macro. >> Scale are returned as VAL_INT_PLUS_MICRO. >> Additionally, I have add device name. > > +#define RAW_TO_GAUSS(asa) ((((asa) + 128) * 3000) / 256) > > * > * Since 1uT = 0.01 gauss, our final scale factor becomes: > * > - * Hadj = H * ((ASA + 128) / 256) * 3/10 * 100 > - * Hadj = H * ((ASA + 128) * 30 / 256 > + * Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100 > + * Hadj = H * ((ASA + 128) * 0.003) / 256 > * > * Since ASA doesn't change, we cache the resultant scale factor into the > * device context in ak8975_setup(). > */ > - data->raw_to_gauss[0] = ((data->asa[0] + 128) * 30) >> 8; > + data->raw_to_gauss[0] = RAW_TO_GAUSS(data->asa[0]); > > thank you for following up on this; I don't have the hardware, so I didn't > dare to change the driver... > > the RAW_TO_GAUSS() macro doesn't match the comment Hadj = H * ... anymore > > maybe put this explanation in the patch comment, not the cover letter? > OK. I will resend explanation in the patch comment. > regards, p. > -- Best Regards, Beomho Seo, Assistant Engineer System S/W Lab., Software Center, Samsung Electronics -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
