From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751956AbeA3Ig4 (ORCPT ); Tue, 30 Jan 2018 03:36:56 -0500 Received: from mail.free-electrons.com ([62.4.15.54]:33169 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751511AbeA3Igz (ORCPT ); Tue, 30 Jan 2018 03:36:55 -0500 Date: Tue, 30 Jan 2018 09:36:43 +0100 From: Maxime Ripard To: Philipp Rossak Cc: lee.jones@linaro.org, robh+dt@kernel.org, mark.rutland@arm.com, wens@csie.org, linux@armlinux.org.uk, jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, davem@davemloft.net, hans.verkuil@cisco.com, mchehab@kernel.org, rask@formelder.dk, clabbe.montjoie@gmail.com, sean@mess.org, krzk@kernel.org, quentin.schulz@free-electrons.com, icenowy@aosc.io, edu.molinas@gmail.com, singhalsimran0@gmail.com, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com Subject: Re: [PATCH v2 07/16] iio: adc: sun4i-gpadc-iio: rework: support nvmem calibration data Message-ID: <20180130083642.cdpd7jnthkdrrk5r@flea.lan> References: <20180128232919.12639-1-embed3d@gmail.com> <20180128232919.12639-8-embed3d@gmail.com> <20180129094045.sagz2dnzvdadd4yx@flea.lan> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="6u2ivkblyv2lastj" Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20171215 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --6u2ivkblyv2lastj Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jan 29, 2018 at 01:33:12PM +0100, Philipp Rossak wrote: > > > static const struct gpadc_data sun4i_gpadc_data =3D { > > > @@ -87,6 +89,7 @@ static const struct gpadc_data sun4i_gpadc_data =3D= { > > > .sample_start =3D sun4i_gpadc_sample_start, > > > .sample_end =3D sun4i_gpadc_sample_end, > > > .sensor_count =3D 1, > > > + .supports_nvmem =3D false, > >=20 > > That's already its value if you leave it out. > >=20 > > > }; > > > static const struct gpadc_data sun5i_gpadc_data =3D { > > > @@ -100,6 +103,7 @@ static const struct gpadc_data sun5i_gpadc_data = =3D { > > > .sample_start =3D sun4i_gpadc_sample_start, > > > .sample_end =3D sun4i_gpadc_sample_end, > > > .sensor_count =3D 1, > > > + .supports_nvmem =3D false, > > > }; > > > static const struct gpadc_data sun6i_gpadc_data =3D { > > > @@ -113,6 +117,7 @@ static const struct gpadc_data sun6i_gpadc_data = =3D { > > > .sample_start =3D sun4i_gpadc_sample_start, > > > .sample_end =3D sun4i_gpadc_sample_end, > > > .sensor_count =3D 1, > > > + .supports_nvmem =3D false, > > > }; > > > static const struct gpadc_data sun8i_a33_gpadc_data =3D { > > > @@ -123,6 +128,7 @@ static const struct gpadc_data sun8i_a33_gpadc_da= ta =3D { > > > .sample_start =3D sun4i_gpadc_sample_start, > > > .sample_end =3D sun4i_gpadc_sample_end, > > > .sensor_count =3D 1, > > > + .supports_nvmem =3D false, > > > }; > > > struct sun4i_gpadc_iio { > > > @@ -141,6 +147,8 @@ struct sun4i_gpadc_iio { > > > struct clk *mod_clk; > > > struct reset_control *reset; > > > int sensor_id; > > > + u32 calibration_data[2]; > > > + bool has_calibration_data[2]; > >=20 > > Why do you have two different values here? >=20 > I think my idea was too complex! I thought it would be better to check if > calibration data was read, and is able to be written to hardware. those > information were split per register. >=20 > I think a u64 should be fine for calibration_data. When I write the > calibration data I can check on the sensor count and write only the lower= 32 > bits if there are less than 3 sensors. >=20 > Is this ok for you? I'd need to see the implementation, but make sure that this is documented in your driver :) >=20 > > > /* prevents concurrent reads of temperature and ADC */ > > > struct mutex mutex; > > > struct thermal_zone_device *tzd; > > > @@ -561,6 +569,9 @@ static int sun4i_gpadc_probe_dt(struct platform_d= evice *pdev, > > > struct resource *mem; > > > void __iomem *base; > > > int ret; > > > + struct nvmem_cell *cell; > > > + ssize_t cell_size; > > > + u64 *cell_data; > > > info->data =3D of_device_get_match_data(&pdev->dev); > > > if (!info->data) > > > @@ -575,6 +586,39 @@ static int sun4i_gpadc_probe_dt(struct platform_= device *pdev, > > > if (IS_ERR(base)) > > > return PTR_ERR(base); > > > + info->has_calibration_data[0] =3D false; > > > + info->has_calibration_data[1] =3D false; > > > + > > > + if (!info->data->supports_nvmem) > > > + goto no_nvmem; > > > + > > > + cell =3D nvmem_cell_get(&pdev->dev, "calibration"); > > > + if (IS_ERR(cell)) { > > > + if (PTR_ERR(cell) =3D=3D -EPROBE_DEFER) > > > + return PTR_ERR(cell); > > > + goto no_nvmem; > >=20 > > goto considered evil ? :) >=20 > this was a suggestion from Jonatan in version one, to make the code better > readable. Isn't if (info->data->supports_nvmem && IS_ERR(cell =3D nvmem_cell_get())) pretty much the same thing? 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