From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 426F3205E30; Sat, 20 Apr 2024 11:02:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713610971; cv=none; b=N1n96egSUc6ilKq5T39SomJaAZcKxXjCMq/IeA4GGYU26aUr8cfFj/CJFdpiVJgVyNOaRiJGgToc9vtAQo5W/oJ+x6+WZrwcXMYgj00QTaNhe8ZdlKQnEB4+qXJjuKI1cIFRyhFt+YZ/1JtKW75cyL3O4mgaFV/V2k3kYkdfJSM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713610971; c=relaxed/simple; bh=Bz8Fp8hN4Mlc9ZnQKuGXEkk/3st/E9Rbstg5YTsOdv8=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=af58GAQ5i1GnLWnEjXwUBYz3blQh0kR9rXcUeZvyltT8H9J3Wxl7Wwvdlh8lV0IuGlcdvMwriK2Tdtj6JHIuVP82tpCSFOxavX2u1rygYm3nYkg0MHB2zt6JvdtYIBxoD6MltVD2Rp2JG0Yd4SoSl/iLsM3c50SLAH4PsuIDSOg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UoKNOhOs; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UoKNOhOs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17CA9C072AA; Sat, 20 Apr 2024 11:02:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713610970; bh=Bz8Fp8hN4Mlc9ZnQKuGXEkk/3st/E9Rbstg5YTsOdv8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=UoKNOhOsf0AqhmGSvpPxyL48GbB/m9Av7fdoj8f/PjgyKCzfwcWjIbRUKwMyc2wP9 mqywb9gYU1HDGq+ROKPNgLyft9BAcdocfsLUde8niKyueGRVjrRpFPz5EOx/zP6z3I 40pqs2RKkBi3ikkq3QL/s8P3jjgrQX4HsBbB90VyPQEbwYj5hwL7WxThpKEwzaNDCK Ibo6XnSPzDTbxG/2iagJrE38ErBHuPboNwwzvBVFX9Q4kTCsqjY09OCLLYDHAky9EP iJGy4Pk22cCs4PW64CaVbc5p55vcJV8Kxp4fmrCE6UChyIwOaz9qGilUSSuLwWzhJL aHfn7HlhRSj4Q== Date: Sat, 20 Apr 2024 12:02:35 +0100 From: Jonathan Cameron To: Alisa-Dariana Roman Cc: michael.hennerich@analog.com, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, alexandru.tachici@analog.com, lars@metafoo.de, robh@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, lgirdwood@gmail.com, broonie@kernel.org, andy@kernel.org, nuno.sa@analog.com, marcelo.schmitt@analog.com, bigunclemax@gmail.com, dlechner@baylibre.com, okan.sahin@analog.com, fr0st61te@gmail.com, alisa.roman@analog.com, marcus.folkesson@gmail.com, schnelle@linux.ibm.com, liambeguin@gmail.com Subject: Re: [PATCH v6 5/5] iio: adc: ad7192: Add AD7194 support Message-ID: <20240420120235.63e32769@jic23-huawei> In-Reply-To: <20240417170054.140587-6-alisa.roman@analog.com> References: <20240417170054.140587-1-alisa.roman@analog.com> <20240417170054.140587-6-alisa.roman@analog.com> X-Mailer: Claws Mail 4.2.0 (GTK 3.24.41; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 17 Apr 2024 20:00:54 +0300 Alisa-Dariana Roman wrote: > Unlike the other AD719Xs, AD7194 has configurable differential > channels. The user can dynamically configure them in the devicetree. > > Also modify config AD7192 description for better scaling. > > Signed-off-by: Alisa-Dariana Roman Late feedback (sorry!) but I think we should resolve the single ended channel description so that it sits at the same level in DT binding as do differential channels. Current situation just feels inconsistent. See DT binding reply. Should be easy to do now, and wouldn't be possible to add later. It would be possible to add support for moving to per channel DT entries for a driver that previously assumed all should be available, but we can't easily move from assuming all single ended channels are but differential are specified by DT child nodes. Jonathan > diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c > index 8d56cf889973..dc113405f1bc 100644 > --- a/drivers/iio/adc/ad7192.c > +++ b/drivers/iio/adc/ad7192.c > @@ -1,6 +1,6 @@ > +static int ad7194_parse_channels(struct iio_dev *indio_dev) > +{ > + struct device *dev = indio_dev->dev.parent; > + struct iio_chan_spec *ad7194_channels; > + struct fwnode_handle *child; > + struct iio_chan_spec ad7194_chan = AD7193_CHANNEL(0, 0, 0); > + struct iio_chan_spec ad7194_chan_diff = AD7193_DIFF_CHANNEL(0, 0, 0, 0); > + struct iio_chan_spec ad7194_chan_temp = AD719x_TEMP_CHANNEL(0, 0); > + struct iio_chan_spec ad7194_chan_timestamp = IIO_CHAN_SOFT_TIMESTAMP(0); > + unsigned int num_channels, index = 0, ain_chan; > + int ret; > + > + num_channels = device_get_child_node_count(dev); > + if (num_channels > AD7194_CH_DIFF_NR_MAX) > + return -EINVAL; > + > + num_channels += AD7194_CH_BASE_NR; > + > + ad7194_channels = devm_kcalloc(dev, num_channels, > + sizeof(*ad7194_channels), GFP_KERNEL); > + if (!ad7194_channels) > + return -ENOMEM; > + > + indio_dev->channels = ad7194_channels; > + indio_dev->num_channels = num_channels; > + > + device_for_each_child_node(dev, child) { > + *ad7194_channels = ad7194_chan_diff; > + ad7194_channels->scan_index = index++; > + ret = ad7194_parse_channel(child, ad7194_channels); > + if (ret) { > + fwnode_handle_put(child); > + return ret; > + } > + ad7194_channels++; > + } > + > + *ad7194_channels = ad7194_chan_temp; > + ad7194_channels->scan_index = index++; > + ad7194_channels->address = AD7194_CH_TEMP; > + ad7194_channels++; > + > + for (ain_chan = 1; ain_chan <= 16; ain_chan++) { I think it's worth making these more similar to the differential channels. Seems odd to allow DT to provide that list, but not the same for single ended. See comment on binding. Should be fairly easy to add now, and if we leave it until later, there won't be a way to move this forwards because we won't be able to tell if no single ended channels in DT means none are relevant, or if it means the DT file predates us adding per single ended channel description. > + *ad7194_channels = ad7194_chan; > + ad7194_channels->scan_index = index++; > + ad7194_channels->channel = ain_chan; > + ad7194_channels->address = AD7194_CH_DIFF(ain_chan, 0); > + ad7194_channels++; > + } > + > + *ad7194_channels = ad7194_chan_timestamp; > + ad7194_channels->scan_index = index; > + > + return 0; > +}