From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Cameron Subject: Re: [PATCH v2 5/5] iio: adc: at91-sama5d2_adc: use max sample rate Date: Sun, 15 Oct 2017 11:28:47 +0100 Message-ID: <20171015112847.5c035e7a@archlinux> References: <1507703732-29175-1-git-send-email-eugen.hristev@microchip.com> <1507703732-29175-6-git-send-email-eugen.hristev@microchip.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1507703732-29175-6-git-send-email-eugen.hristev-UWL1GkI3JZL3oGB3hsPCZA@public.gmane.org> Sender: linux-iio-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Eugen Hristev Cc: nicolas.ferre-UWL1GkI3JZL3oGB3hsPCZA@public.gmane.org, alexandre.belloni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ludovic.desroches-UWL1GkI3JZL3oGB3hsPCZA@public.gmane.org List-Id: devicetree@vger.kernel.org On Wed, 11 Oct 2017 09:35:32 +0300 Eugen Hristev wrote: > Change driver settings to use maximum sample rate clock. > This is useful to achieve best possible sampling rate > if we use DMA. > > Signed-off-by: Eugen Hristev I would normally expect this to have some bearing on the noise levels on the measured signals. All I can find is a reference to the track time being 15*a single clock cycle. We could change this so that it is appropriate for the currently samping frequency rather than leaving it as a fixed value. Jonathan > --- > drivers/iio/adc/at91-sama5d2_adc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c > index 7e51ecb..b76f88f 100644 > --- a/drivers/iio/adc/at91-sama5d2_adc.c > +++ b/drivers/iio/adc/at91-sama5d2_adc.c > @@ -934,7 +934,7 @@ static void at91_adc_hw_init(struct at91_adc_state *st) > at91_adc_writel(st, AT91_SAMA5D2_MR, > AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH); > > - at91_adc_setup_samp_freq(st, st->soc_info.min_sample_rate); > + at91_adc_setup_samp_freq(st, st->soc_info.max_sample_rate); > } > > static ssize_t at91_adc_get_fifo_state(struct device *dev,