From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:37549 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755436AbcAIQ2o (ORCPT ); Sat, 9 Jan 2016 11:28:44 -0500 Subject: Re: [PATCH] iio: adc: mcp320x: support more differential voltage measurement To: Akinobu Mita , linux-iio@vger.kernel.org References: <1452181230-21877-1-git-send-email-akinobu.mita@gmail.com> Cc: Oskar Andero , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald From: Jonathan Cameron Message-ID: <56913539.2080904@kernel.org> Date: Sat, 9 Jan 2016 16:28:41 +0000 MIME-Version: 1.0 In-Reply-To: <1452181230-21877-1-git-send-email-akinobu.mita@gmail.com> Content-Type: text/plain; charset=windows-1252 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 07/01/16 15:40, Akinobu Mita wrote: > mcp320x driver supports the pseudo-differential mode by > in_voltage'IN+'-voltage'IN-'_raw where (IN+, IN-) = (0, 1), (2, 3), ... > > mcp320x chips except MCP3X01 can also select swapped IN+ and IN- > pairs in the pseudo-differential mode. > i.e. in_voltage'IN+'-voltage'IN-'_raw where (IN+, IN-) = (1, 0), > (3, 2), ... > > If the voltage level of IN+ is equal to or less than IN-, the > resultant code will be 000h. So it is useful to provide these, too. > > Signed-off-by: Akinobu Mita > Cc: Oskar Andero > Cc: Jonathan Cameron > Cc: Hartmut Knaack > Cc: Lars-Peter Clausen > Cc: Peter Meerwald > Cc: linux-iio@vger.kernel.org Looks good to me. Will let it sit for a while longer on the list as we have lots of time at this point in a kernel cycle (new one has just started as far as IIO is concerned) Jonathan > --- > drivers/iio/adc/mcp320x.c | 31 +++++++++++++++++++------------ > 1 file changed, 19 insertions(+), 12 deletions(-) > > diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c > index 8569c8e..a9c4acd 100644 > --- a/drivers/iio/adc/mcp320x.c > +++ b/drivers/iio/adc/mcp320x.c > @@ -187,26 +187,27 @@ out: > .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ > } > > -#define MCP320X_VOLTAGE_CHANNEL_DIFF(num) \ > +#define MCP320X_VOLTAGE_CHANNEL_DIFF(chan1, chan2) \ > { \ > .type = IIO_VOLTAGE, \ > .indexed = 1, \ > - .channel = (num * 2), \ > - .channel2 = (num * 2 + 1), \ > - .address = (num * 2), \ > + .channel = (chan1), \ > + .channel2 = (chan2), \ > + .address = (chan1), \ > .differential = 1, \ > .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ > } > > static const struct iio_chan_spec mcp3201_channels[] = { > - MCP320X_VOLTAGE_CHANNEL_DIFF(0), > + MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1), > }; > > static const struct iio_chan_spec mcp3202_channels[] = { > MCP320X_VOLTAGE_CHANNEL(0), > MCP320X_VOLTAGE_CHANNEL(1), > - MCP320X_VOLTAGE_CHANNEL_DIFF(0), > + MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1), > + MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0), > }; > > static const struct iio_chan_spec mcp3204_channels[] = { > @@ -214,8 +215,10 @@ static const struct iio_chan_spec mcp3204_channels[] = { > MCP320X_VOLTAGE_CHANNEL(1), > MCP320X_VOLTAGE_CHANNEL(2), > MCP320X_VOLTAGE_CHANNEL(3), > - MCP320X_VOLTAGE_CHANNEL_DIFF(0), > - MCP320X_VOLTAGE_CHANNEL_DIFF(1), > + MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1), > + MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0), > + MCP320X_VOLTAGE_CHANNEL_DIFF(2, 3), > + MCP320X_VOLTAGE_CHANNEL_DIFF(3, 2), > }; > > static const struct iio_chan_spec mcp3208_channels[] = { > @@ -227,10 +230,14 @@ static const struct iio_chan_spec mcp3208_channels[] = { > MCP320X_VOLTAGE_CHANNEL(5), > MCP320X_VOLTAGE_CHANNEL(6), > MCP320X_VOLTAGE_CHANNEL(7), > - MCP320X_VOLTAGE_CHANNEL_DIFF(0), > - MCP320X_VOLTAGE_CHANNEL_DIFF(1), > - MCP320X_VOLTAGE_CHANNEL_DIFF(2), > - MCP320X_VOLTAGE_CHANNEL_DIFF(3), > + MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1), > + MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0), > + MCP320X_VOLTAGE_CHANNEL_DIFF(2, 3), > + MCP320X_VOLTAGE_CHANNEL_DIFF(3, 2), > + MCP320X_VOLTAGE_CHANNEL_DIFF(4, 5), > + MCP320X_VOLTAGE_CHANNEL_DIFF(5, 4), > + MCP320X_VOLTAGE_CHANNEL_DIFF(6, 7), > + MCP320X_VOLTAGE_CHANNEL_DIFF(7, 6), > }; > > static const struct iio_info mcp320x_info = { >