Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753571AbbFHUJb (ORCPT ); Mon, 8 Jun 2015 16:09:31 -0400 Received: from mail.kmu-office.ch ([178.209.48.109]:38218 "EHLO mail.kmu-office.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752355AbbFHUJU (ORCPT ); Mon, 8 Jun 2015 16:09:20 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Date: Mon, 08 Jun 2015 22:07:09 +0200 From: Stefan Agner To: Rob Herring Cc: Jonathan Cameron , Shawn Guo , kernel@pengutronix.de, knaack.h@gmx.de, Lars-Peter Clausen , Peter Meerwald , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Fugang Duan , maitysanchayan@gmail.com, devicetree@vger.kernel.org, linux-iio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 1/2] iio: adc: vf610: implement configurable conversion modes In-Reply-To: References: <1432730872-14325-1-git-send-email-stefan@agner.ch> <1432730872-14325-2-git-send-email-stefan@agner.ch> Message-ID: <14d469dedae9de1ce519fe90401e526e@agner.ch> User-Agent: Roundcube Webmail/1.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3074 Lines: 68 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@vger.kernel.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. -- Stefan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/