From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751826AbeA2MdT (ORCPT ); Mon, 29 Jan 2018 07:33:19 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:34609 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751297AbeA2MdQ (ORCPT ); Mon, 29 Jan 2018 07:33:16 -0500 X-Google-Smtp-Source: AH8x227rAKBTuyZaNDY7jPSldjDepYR4XDAgwajo43LJbofM+EKPkF/kA4f87DDoa+I74x6W4Gvm0Q== Subject: Re: [PATCH v2 07/16] iio: adc: sun4i-gpadc-iio: rework: support nvmem calibration data To: Maxime Ripard 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 References: <20180128232919.12639-1-embed3d@gmail.com> <20180128232919.12639-8-embed3d@gmail.com> <20180129094045.sagz2dnzvdadd4yx@flea.lan> From: Philipp Rossak Message-ID: Date: Mon, 29 Jan 2018 13:33:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20180129094045.sagz2dnzvdadd4yx@flea.lan> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 29.01.2018 10:40, Maxime Ripard wrote: > On Mon, Jan 29, 2018 at 12:29:10AM +0100, Philipp Rossak wrote: >> This patch reworks the driver to support nvmem calibration cells. >> The driver checks if the nvmem calibration is supported and reads out >> the nvmem. >> >> Signed-off-by: Philipp Rossak >> --- >> drivers/iio/adc/sun4i-gpadc-iio.c | 44 +++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 44 insertions(+) >> >> diff --git a/drivers/iio/adc/sun4i-gpadc-iio.c b/drivers/iio/adc/sun4i-gpadc-iio.c >> index ac9ad2f8232f..74eeb5cd5218 100644 >> --- a/drivers/iio/adc/sun4i-gpadc-iio.c >> +++ b/drivers/iio/adc/sun4i-gpadc-iio.c >> @@ -27,6 +27,7 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> #include >> @@ -74,6 +75,7 @@ struct gpadc_data { >> bool has_bus_rst; >> bool has_mod_clk; >> int sensor_count; >> + bool supports_nvmem; > > I think you should add some documentation along with all the fields > you're adding. ok I will add more informations in the next version into the commit message. > >> }; >> >> static const struct gpadc_data sun4i_gpadc_data = { >> @@ -87,6 +89,7 @@ static const struct gpadc_data sun4i_gpadc_data = { >> .sample_start = sun4i_gpadc_sample_start, >> .sample_end = sun4i_gpadc_sample_end, >> .sensor_count = 1, >> + .supports_nvmem = false, > > That's already its value if you leave it out. > >> }; >> >> static const struct gpadc_data sun5i_gpadc_data = { >> @@ -100,6 +103,7 @@ static const struct gpadc_data sun5i_gpadc_data = { >> .sample_start = sun4i_gpadc_sample_start, >> .sample_end = sun4i_gpadc_sample_end, >> .sensor_count = 1, >> + .supports_nvmem = false, >> }; >> >> static const struct gpadc_data sun6i_gpadc_data = { >> @@ -113,6 +117,7 @@ static const struct gpadc_data sun6i_gpadc_data = { >> .sample_start = sun4i_gpadc_sample_start, >> .sample_end = sun4i_gpadc_sample_end, >> .sensor_count = 1, >> + .supports_nvmem = false, >> }; >> >> static const struct gpadc_data sun8i_a33_gpadc_data = { >> @@ -123,6 +128,7 @@ static const struct gpadc_data sun8i_a33_gpadc_data = { >> .sample_start = sun4i_gpadc_sample_start, >> .sample_end = sun4i_gpadc_sample_end, >> .sensor_count = 1, >> + .supports_nvmem = 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]; > > Why do you have two different values here? > 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. 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. Is this ok for you? >> /* 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_device *pdev, >> struct resource *mem; >> void __iomem *base; >> int ret; >> + struct nvmem_cell *cell; >> + ssize_t cell_size; >> + u64 *cell_data; >> >> info->data = 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] = false; >> + info->has_calibration_data[1] = false; >> + >> + if (!info->data->supports_nvmem) >> + goto no_nvmem; >> + >> + cell = nvmem_cell_get(&pdev->dev, "calibration"); >> + if (IS_ERR(cell)) { >> + if (PTR_ERR(cell) == -EPROBE_DEFER) >> + return PTR_ERR(cell); >> + goto no_nvmem; > > goto considered evil ? :) > this was a suggestion from Jonatan in version one, to make the code better readable. . >> + } >> + >> + cell_data = (u64 *)nvmem_cell_read(cell, &cell_size); >> + nvmem_cell_put(cell); >> + switch (cell_size) { >> + case 8: >> + case 6: >> + info->has_calibration_data[1] = true; >> + info->calibration_data[1] = be32_to_cpu( >> + upper_32_bits(cell_data[0])); >> + case 4: >> + case 2: >> + info->has_calibration_data[0] = true; >> + info->calibration_data[0] = be32_to_cpu( >> + lower_32_bits(cell_data[0])); > > Why do you need that switch? You are right! The calibration reg seems to be always 64 bit wide. [1] So I will just check for the length of 8. > > Thanks! > Maxime > [1]: http://linux-sunxi.org/SID_Register_Guide#eFUSE Thanks, Philipp