From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6BE62C47404 for ; Mon, 7 Oct 2019 14:07:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 383CE21871 for ; Mon, 7 Oct 2019 14:07:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570457255; bh=icumd2RfScngpPqzmnh8fk83usHw8Lm72/hz/SoioaA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=1v1cbdiHKVI0ELuJpFSXJVSmXoNL3yNeTJL0vZNOJN9YTSX0LDxFmsu9Lhk/dDcdc jtMTmEfgcykqCkVaXmPJLuoJF51CNF6bospoGqEb7PYKZJ0vJaOHg+6fBXMAgbkYqP iquSMM80MVbZfjwXka41N+caVro1HvKVkFC8JyIE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727838AbfJGOHe (ORCPT ); Mon, 7 Oct 2019 10:07:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:45736 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727324AbfJGOHe (ORCPT ); Mon, 7 Oct 2019 10:07:34 -0400 Received: from localhost.localdomain (nat-pool-mxp-t.redhat.com [149.6.153.186]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 80666206C2; Mon, 7 Oct 2019 14:07:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570457253; bh=icumd2RfScngpPqzmnh8fk83usHw8Lm72/hz/SoioaA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IcCwDUo5rWmoy3LKun8nvnWJ2Ua3g7bVkCPDyZgeeVQXa0qx9TYSzdGUAqVWGxDmm bjXaSiwQiKdw5bt0Hb+0RYHdZiMKiawCrdOpPUnPTBlj+EZmq7pDEEfgtnBAvLBzLt Df05O4A06SCo88vG23/ePlAP8crKc3l1NJ5Lw2d0= Date: Mon, 7 Oct 2019 16:07:27 +0200 From: Lorenzo Bianconi To: Mario Tesi Cc: lorenzo.bianconi83@gmail.com, jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, linux-iio@vger.kernel.org Subject: Re: [PATCH] iio: imu: st_lsm6dsx: add odr calibration feature Message-ID: <20191007140727.GE3192@localhost.localdomain> References: <1570456586-16696-1-git-send-email-mario.tesi@st.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="qOrJKOH36bD5yhNe" Content-Disposition: inline In-Reply-To: <1570456586-16696-1-git-send-email-mario.tesi@st.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org --qOrJKOH36bD5yhNe Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > On LSM6DSO/LSM6DSR/LSM6DSOX/ASM330LHH and ISH330DHCX > devices it is possible to trim the hardware timestamp > resolution through the FREQ_FINE[7:0] bits of the > INTERNAL_FREQ_FINE register, which contains the difference > in percentage of the effective ODR (and timestamp rate) > with respect to the typical value. >=20 > The formula for calculating the effective ODR reported > in the application notes has been linearized to the first > order to simplify the calculation (pls. see note on source > code). >=20 > This change may be useful in the outcome of CTS > tests regarding the SingleSensorTests and the > SensorTest#testSensorTimeStamps for high ODRs >=20 > Signed-off-by: Mario Tesi Acked-by: Lorenzo Bianconi > --- > drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h | 4 ++++ > drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 5 ++--- > drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 23 ++++++++++++++++++++= +++ > 3 files changed, 29 insertions(+), 3 deletions(-) >=20 > diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h b/drivers/iio/imu/st= _lsm6dsx/st_lsm6dsx.h > index 7485423..9a40587 100644 > --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h > +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h > @@ -153,12 +153,14 @@ struct st_lsm6dsx_fifo_ops { > * @hr_timer: Hw timer resolution register info (addr + mask). > * @fifo_en: Hw timer FIFO enable register info (addr + mask). > * @decimator: Hw timer FIFO decimator register info (addr + mask). > + * @freq_fine: Difference in % of ODR with respect to the typical. > */ > struct st_lsm6dsx_hw_ts_settings { > struct st_lsm6dsx_reg timer_en; > struct st_lsm6dsx_reg hr_timer; > struct st_lsm6dsx_reg fifo_en; > struct st_lsm6dsx_reg decimator; > + u8 freq_fine; > }; > =20 > /** > @@ -344,6 +346,7 @@ struct st_lsm6dsx_sensor { > * @fifo_mode: FIFO operating mode supported by the device. > * @suspend_mask: Suspended sensor bitmask. > * @enable_mask: Enabled sensor bitmask. > + * @ts_gain: Hw timestamp rate after internal calibration. > * @ts_sip: Total number of timestamp samples in a given pattern. > * @sip: Total number of samples (acc/gyro/ts) in a given pattern. > * @buff: Device read buffer. > @@ -365,6 +368,7 @@ struct st_lsm6dsx_hw { > enum st_lsm6dsx_fifo_mode fifo_mode; > u8 suspend_mask; > u8 enable_mask; > + s64 ts_gain; > u8 ts_sip; > u8 sip; > =20 > diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio= /imu/st_lsm6dsx/st_lsm6dsx_buffer.c > index cabd4bf..d7cacb9 100644 > --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c > +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c > @@ -50,7 +50,6 @@ > =20 > #define ST_LSM6DSX_MAX_FIFO_ODR_VAL 0x08 > =20 > -#define ST_LSM6DSX_TS_SENSITIVITY 25000UL /* 25us */ > #define ST_LSM6DSX_TS_RESET_VAL 0xaa > =20 > struct st_lsm6dsx_decimator_entry { > @@ -423,7 +422,7 @@ int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw) > */ > if (!reset_ts && ts >=3D 0xff0000) > reset_ts =3D true; > - ts *=3D ST_LSM6DSX_TS_SENSITIVITY; > + ts *=3D hw->ts_gain; > =20 > offset +=3D ST_LSM6DSX_SAMPLE_SIZE; > } > @@ -566,7 +565,7 @@ int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw = *hw) > */ > if (!reset_ts && ts >=3D 0xffff0000) > reset_ts =3D true; > - ts *=3D ST_LSM6DSX_TS_SENSITIVITY; > + ts *=3D hw->ts_gain; > } else { > st_lsm6dsx_push_tagged_data(hw, tag, iio_buff, > ts); > diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/i= mu/st_lsm6dsx/st_lsm6dsx_core.c > index bacc908..2b54ce1 100644 > --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c > +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c > @@ -63,6 +63,8 @@ > =20 > #define ST_LSM6DSX_REG_WHOAMI_ADDR 0x0f > =20 > +#define ST_LSM6DSX_TS_SENSITIVITY 25000UL /* 25us */ > + > static const struct iio_chan_spec st_lsm6dsx_acc_channels[] =3D { > ST_LSM6DSX_CHANNEL_ACC(IIO_ACCEL, 0x28, IIO_MOD_X, 0), > ST_LSM6DSX_CHANNEL_ACC(IIO_ACCEL, 0x2a, IIO_MOD_Y, 1), > @@ -832,6 +834,7 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_se= nsor_settings[] =3D { > .addr =3D 0x0a, > .mask =3D GENMASK(7, 6), > }, > + .freq_fine =3D 0x63, > }, > .shub_settings =3D { > .page_mux =3D { > @@ -1020,6 +1023,7 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_= sensor_settings[] =3D { > .addr =3D 0x0a, > .mask =3D GENMASK(7, 6), > }, > + .freq_fine =3D 0x63, > }, > .event_settings =3D { > .enable_reg =3D { > @@ -1185,6 +1189,7 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_= sensor_settings[] =3D { > .addr =3D 0x0a, > .mask =3D GENMASK(7, 6), > }, > + .freq_fine =3D 0x63, > }, > .shub_settings =3D { > .page_mux =3D { > @@ -1874,6 +1879,24 @@ static int st_lsm6dsx_init_hw_timer(struct st_lsm6= dsx_hw *hw) > if (err < 0) > return err; > } > + > + /* calibrate timestamp sensitivity */ > + hw->ts_gain =3D ST_LSM6DSX_TS_SENSITIVITY; > + if (ts_settings->freq_fine) { > + err =3D regmap_read(hw->regmap, ts_settings->freq_fine, &val); > + if (err < 0) > + return err; > + > + /* > + * linearize the AN5192 formula: > + * 1 / (1 + x) ~=3D 1 - x (Taylor=E2=80=99s Series) > + * ttrim[s] =3D 1 / (40000 * (1 + 0.0015 * val)) > + * ttrim[ns] ~=3D 25000 - 37.5 * val > + * ttrim[ns] ~=3D 25000 - (37500 * val) / 1000 > + */ > + hw->ts_gain -=3D ((s8)val * 37500) / 1000; > + } > + > return 0; > } > =20 > --=20 > 2.7.4 >=20 --qOrJKOH36bD5yhNe Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTquNwa3Txd3rGGn7Y6cBh0uS2trAUCXZtGnQAKCRA6cBh0uS2t rNTyAQDd0dmPDKckQfoI1Si9epDrABY1fZyNi84NwpfRdp7gAAD/cm+7Pg/zJaEA jx2Zs4pdh7/eGeQnXPN2DuKNU4EBJQ0= =Kgjk -----END PGP SIGNATURE----- --qOrJKOH36bD5yhNe--