From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Cameron Subject: Re: [PATCH v5 1/2] iio: adc: vf610: implement configurable conversion modes Date: Sun, 14 Jun 2015 12:12:04 +0100 Message-ID: <557D6184.90105@kernel.org> References: <1432730872-14325-1-git-send-email-stefan@agner.ch> <1432730872-14325-2-git-send-email-stefan@agner.ch> <14d469dedae9de1ce519fe90401e526e@agner.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <14d469dedae9de1ce519fe90401e526e-XLVq0VzYD2Y@public.gmane.org> Sender: linux-iio-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Stefan Agner , Rob Herring Cc: Shawn Guo , kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, knaack.h-Mmb7MZpHnFY@public.gmane.org, Lars-Peter Clausen , Peter Meerwald , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Fugang Duan , maitysanchayan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On 08/06/15 21:07, Stefan Agner wrote: > On 2015-06-08 19:49, Rob Herring wrote: >> On Wed, May 27, 2015 at 7:47 AM, Stefan Agner wrote: >>> Support configurable conversion mode through sysfs. So far, the >>> mode used was low-power, which is enabled by default now. Beside >>> that, the modes normal and high-speed are selectable as well. >>> >>> Use the new device tree property which specifies the maximum ADC >>> conversion clock frequencies. Depending on the mode used, the >>> available resulting conversion frequency are calculated >>> dynamically. >>> >>> Acked-by: Fugang Duan >>> Signed-off-by: Stefan Agner >>> --- >>> Documentation/ABI/testing/sysfs-bus-iio-vf610 | 7 + >>> .../devicetree/bindings/iio/adc/vf610-adc.txt | 9 ++ >>> drivers/iio/adc/vf610_adc.c | 146 +++++++++++++++------ >>> 3 files changed, 120 insertions(+), 42 deletions(-) >>> create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-vf610 >>> >>> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-vf610 b/Documentation/ABI/testing/sysfs-bus-iio-vf610 >>> new file mode 100644 >>> index 0000000..ecbc1f4 >>> --- /dev/null >>> +++ b/Documentation/ABI/testing/sysfs-bus-iio-vf610 >>> @@ -0,0 +1,7 @@ >>> +What: /sys/bus/iio/devices/iio:deviceX/conversion_mode >>> +KernelVersion: 4.2 >>> +Contact: linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org >>> +Description: >>> + Specifies the hardware conversion mode used. The three >>> + available modes are "normal", "high-speed" and "low-power", >>> + where the last is the default mode. >>> diff --git a/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt b/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt >>> index 1a4a43d..3eb40e2 100644 >>> --- a/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt >>> +++ b/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt >>> @@ -11,6 +11,13 @@ Required properties: >>> - clock-names: Must contain "adc", matching entry in the clocks property. >>> - vref-supply: The regulator supply ADC reference voltage. >>> >>> +Recommended properties: >>> +- fsl,adck-max-frequency: Maximum frequencies according to datasheets operating >>> + requirements. Three values are required, depending on conversion mode: >>> + - Frequency in normal mode (ADLPC=0, ADHSC=0) >>> + - Frequency in high-speed mode (ADLPC=0, ADHSC=1) >>> + - Frequency in low-power mode (ADLPC=1, ADHSC=0) >> >> Why is this "adck" rather than "adc"? > > That is the name of the clock according to the reference manual and data > sheet. > >> How is this related to today's patch adding min-sample-time? > > It is related in that this clock is the base to calculate the sampling > time, but otherwise not really related. Afaik, not respecting the > maximum clock frequency is probably more a issue for the SAR part of the > ADC. Rob, are you happy with Stefan's responses? > > -- > Stefan > > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >