linux-iio.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jonathan Cameron <jic23@kernel.org>
To: "Nuno Sá" <nuno.sa@analog.com>
Cc: <linux-iio@vger.kernel.org>, Lars-Peter Clausen <lars@metafoo.de>,
	Michael Hennerich <Michael.Hennerich@analog.com>,
	Hartmut Knaack <knaack.h@gmx.de>,
	Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Subject: Re: [PATCH v2 1/2] iio: adis16480: Fix scales factors
Date: Sun, 3 Nov 2019 11:56:18 +0000	[thread overview]
Message-ID: <20191103115618.195c3064@archlinux> (raw)
In-Reply-To: <20191028163349.28866-1-nuno.sa@analog.com>

On Mon, 28 Oct 2019 17:33:48 +0100
Nuno Sá <nuno.sa@analog.com> wrote:

> This patch fixes the scales for the gyroscope, accelerometer and
> barometer. The pressure scale was just wrong. For the others, the scale
> factors were not taking into account that a 32bit word is being read
> from the device.
> 
> Fixes: 7abad1063deb ("iio: adis16480: Fix scale factors")
> Fixes: 82e7a1b25017 ("iio: imu: adis16480: Add support for ADIS1649x family of devices")
> Cc: <Stable@vger.kernel.org>
> 
> Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Applied to the fixes-togreg branch of iio.git. It's possible I'll pull
these across to the togreg branch fo the next merge window depending on 
timing and what else is in my tree.

thanks,

Jonathan

> ---
> Changes in v2:
>  * Correct the Fixes tag.
> 
>  drivers/iio/imu/adis16480.c | 77 ++++++++++++++++++++-----------------
>  1 file changed, 41 insertions(+), 36 deletions(-)
> 
> diff --git a/drivers/iio/imu/adis16480.c b/drivers/iio/imu/adis16480.c
> index b99d73887c9f..3b53bbb11bfb 100644
> --- a/drivers/iio/imu/adis16480.c
> +++ b/drivers/iio/imu/adis16480.c
> @@ -620,9 +620,13 @@ static int adis16480_read_raw(struct iio_dev *indio_dev,
>  			*val2 = (st->chip_info->temp_scale % 1000) * 1000;
>  			return IIO_VAL_INT_PLUS_MICRO;
>  		case IIO_PRESSURE:
> -			*val = 0;
> -			*val2 = 4000; /* 40ubar = 0.004 kPa */
> -			return IIO_VAL_INT_PLUS_MICRO;
> +			/*
> +			 * max scale is 1310 mbar
> +			 * max raw value is 32767 shifted for 32bits
> +			 */
> +			*val = 131; /* 1310mbar = 131 kPa */
> +			*val2 = 32767 << 16;
> +			return IIO_VAL_FRACTIONAL;
>  		default:
>  			return -EINVAL;
>  		}
> @@ -783,13 +787,14 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
>  		.channels = adis16485_channels,
>  		.num_channels = ARRAY_SIZE(adis16485_channels),
>  		/*
> -		 * storing the value in rad/degree and the scale in degree
> -		 * gives us the result in rad and better precession than
> -		 * storing the scale directly in rad.
> +		 * Typically we do IIO_RAD_TO_DEGREE in the denominator, which
> +		 * is exactly the same as IIO_DEGREE_TO_RAD in numerator, since
> +		 * it gives better approximation. However, in this case we
> +		 * cannot do it since it would not fit in a 32bit variable.
>  		 */
> -		.gyro_max_val = IIO_RAD_TO_DEGREE(22887),
> -		.gyro_max_scale = 300,
> -		.accel_max_val = IIO_M_S_2_TO_G(21973),
> +		.gyro_max_val = 22887 << 16,
> +		.gyro_max_scale = IIO_DEGREE_TO_RAD(300),
> +		.accel_max_val = IIO_M_S_2_TO_G(21973 << 16),
>  		.accel_max_scale = 18,
>  		.temp_scale = 5650, /* 5.65 milli degree Celsius */
>  		.int_clk = 2460000,
> @@ -799,9 +804,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
>  	[ADIS16480] = {
>  		.channels = adis16480_channels,
>  		.num_channels = ARRAY_SIZE(adis16480_channels),
> -		.gyro_max_val = IIO_RAD_TO_DEGREE(22500),
> -		.gyro_max_scale = 450,
> -		.accel_max_val = IIO_M_S_2_TO_G(12500),
> +		.gyro_max_val = 22500 << 16,
> +		.gyro_max_scale = IIO_DEGREE_TO_RAD(450),
> +		.accel_max_val = IIO_M_S_2_TO_G(12500 << 16),
>  		.accel_max_scale = 10,
>  		.temp_scale = 5650, /* 5.65 milli degree Celsius */
>  		.int_clk = 2460000,
> @@ -811,9 +816,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
>  	[ADIS16485] = {
>  		.channels = adis16485_channels,
>  		.num_channels = ARRAY_SIZE(adis16485_channels),
> -		.gyro_max_val = IIO_RAD_TO_DEGREE(22500),
> -		.gyro_max_scale = 450,
> -		.accel_max_val = IIO_M_S_2_TO_G(20000),
> +		.gyro_max_val = 22500 << 16,
> +		.gyro_max_scale = IIO_DEGREE_TO_RAD(450),
> +		.accel_max_val = IIO_M_S_2_TO_G(20000 << 16),
>  		.accel_max_scale = 5,
>  		.temp_scale = 5650, /* 5.65 milli degree Celsius */
>  		.int_clk = 2460000,
> @@ -823,9 +828,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
>  	[ADIS16488] = {
>  		.channels = adis16480_channels,
>  		.num_channels = ARRAY_SIZE(adis16480_channels),
> -		.gyro_max_val = IIO_RAD_TO_DEGREE(22500),
> -		.gyro_max_scale = 450,
> -		.accel_max_val = IIO_M_S_2_TO_G(22500),
> +		.gyro_max_val = 22500 << 16,
> +		.gyro_max_scale = IIO_DEGREE_TO_RAD(450),
> +		.accel_max_val = IIO_M_S_2_TO_G(22500 << 16),
>  		.accel_max_scale = 18,
>  		.temp_scale = 5650, /* 5.65 milli degree Celsius */
>  		.int_clk = 2460000,
> @@ -835,9 +840,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
>  	[ADIS16495_1] = {
>  		.channels = adis16485_channels,
>  		.num_channels = ARRAY_SIZE(adis16485_channels),
> -		.gyro_max_val = IIO_RAD_TO_DEGREE(20000),
> -		.gyro_max_scale = 125,
> -		.accel_max_val = IIO_M_S_2_TO_G(32000),
> +		.gyro_max_val = 20000 << 16,
> +		.gyro_max_scale = IIO_DEGREE_TO_RAD(125),
> +		.accel_max_val = IIO_M_S_2_TO_G(32000 << 16),
>  		.accel_max_scale = 8,
>  		.temp_scale = 12500, /* 12.5 milli degree Celsius */
>  		.int_clk = 4250000,
> @@ -848,9 +853,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
>  	[ADIS16495_2] = {
>  		.channels = adis16485_channels,
>  		.num_channels = ARRAY_SIZE(adis16485_channels),
> -		.gyro_max_val = IIO_RAD_TO_DEGREE(18000),
> -		.gyro_max_scale = 450,
> -		.accel_max_val = IIO_M_S_2_TO_G(32000),
> +		.gyro_max_val = 18000 << 16,
> +		.gyro_max_scale = IIO_DEGREE_TO_RAD(450),
> +		.accel_max_val = IIO_M_S_2_TO_G(32000 << 16),
>  		.accel_max_scale = 8,
>  		.temp_scale = 12500, /* 12.5 milli degree Celsius */
>  		.int_clk = 4250000,
> @@ -861,9 +866,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
>  	[ADIS16495_3] = {
>  		.channels = adis16485_channels,
>  		.num_channels = ARRAY_SIZE(adis16485_channels),
> -		.gyro_max_val = IIO_RAD_TO_DEGREE(20000),
> -		.gyro_max_scale = 2000,
> -		.accel_max_val = IIO_M_S_2_TO_G(32000),
> +		.gyro_max_val = 20000 << 16,
> +		.gyro_max_scale = IIO_DEGREE_TO_RAD(2000),
> +		.accel_max_val = IIO_M_S_2_TO_G(32000 << 16),
>  		.accel_max_scale = 8,
>  		.temp_scale = 12500, /* 12.5 milli degree Celsius */
>  		.int_clk = 4250000,
> @@ -874,9 +879,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
>  	[ADIS16497_1] = {
>  		.channels = adis16485_channels,
>  		.num_channels = ARRAY_SIZE(adis16485_channels),
> -		.gyro_max_val = IIO_RAD_TO_DEGREE(20000),
> -		.gyro_max_scale = 125,
> -		.accel_max_val = IIO_M_S_2_TO_G(32000),
> +		.gyro_max_val = 20000 << 16,
> +		.gyro_max_scale = IIO_DEGREE_TO_RAD(125),
> +		.accel_max_val = IIO_M_S_2_TO_G(32000 << 16),
>  		.accel_max_scale = 40,
>  		.temp_scale = 12500, /* 12.5 milli degree Celsius */
>  		.int_clk = 4250000,
> @@ -887,9 +892,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
>  	[ADIS16497_2] = {
>  		.channels = adis16485_channels,
>  		.num_channels = ARRAY_SIZE(adis16485_channels),
> -		.gyro_max_val = IIO_RAD_TO_DEGREE(18000),
> -		.gyro_max_scale = 450,
> -		.accel_max_val = IIO_M_S_2_TO_G(32000),
> +		.gyro_max_val = 18000 << 16,
> +		.gyro_max_scale = IIO_DEGREE_TO_RAD(450),
> +		.accel_max_val = IIO_M_S_2_TO_G(32000 << 16),
>  		.accel_max_scale = 40,
>  		.temp_scale = 12500, /* 12.5 milli degree Celsius */
>  		.int_clk = 4250000,
> @@ -900,9 +905,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
>  	[ADIS16497_3] = {
>  		.channels = adis16485_channels,
>  		.num_channels = ARRAY_SIZE(adis16485_channels),
> -		.gyro_max_val = IIO_RAD_TO_DEGREE(20000),
> -		.gyro_max_scale = 2000,
> -		.accel_max_val = IIO_M_S_2_TO_G(32000),
> +		.gyro_max_val = 20000 << 16,
> +		.gyro_max_scale = IIO_DEGREE_TO_RAD(2000),
> +		.accel_max_val = IIO_M_S_2_TO_G(32000 << 16),
>  		.accel_max_scale = 40,
>  		.temp_scale = 12500, /* 12.5 milli degree Celsius */
>  		.int_clk = 4250000,


      parent reply	other threads:[~2019-11-03 11:56 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-28 16:33 [PATCH v2 1/2] iio: adis16480: Fix scales factors Nuno Sá
2019-10-28 16:33 ` [PATCH v2 2/2] iio: adis16480: Add debugfs_reg_access entry Nuno Sá
2019-11-03 11:58   ` Jonathan Cameron
2019-11-03 11:56 ` Jonathan Cameron [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191103115618.195c3064@archlinux \
    --to=jic23@kernel.org \
    --cc=Michael.Hennerich@analog.com \
    --cc=knaack.h@gmx.de \
    --cc=lars@metafoo.de \
    --cc=linux-iio@vger.kernel.org \
    --cc=nuno.sa@analog.com \
    --cc=pmeerw@pmeerw.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).