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=-4.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,UNWANTED_LANGUAGE_BODY autolearn=unavailable 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 C07AAC282E3 for ; Sun, 26 May 2019 17:35:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7ACAF2085A for ; Sun, 26 May 2019 17:35:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558892151; bh=VUUH7bANa61e20Y9dIDPSXAHiwWeZLuc8JMxfvr+Dtg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=yYVEmwSpFvo4YVFMZTBRN0VAyXvAq1bVjgHZsm19UE23jEVXp3kveijh1YSx4kRZ8 ryDTw+l0g6ky9c1jCv+QKV2+4YjlzU/TuIsAuyVInAWtFHs53SulTd7egj74DYmsQu Us/Q+EEWnN9XEsr/onjussJ9VVdDg7wJyYFkBtB4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727966AbfEZRfv (ORCPT ); Sun, 26 May 2019 13:35:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:59066 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727959AbfEZRfu (ORCPT ); Sun, 26 May 2019 13:35:50 -0400 Received: from archlinux (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (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 4605C20815; Sun, 26 May 2019 17:35:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558892149; bh=VUUH7bANa61e20Y9dIDPSXAHiwWeZLuc8JMxfvr+Dtg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=GG8+8+V8pN1bViTaRx5wyNhHIOYga72sAibLzir3Booo+4bhna2giooNBfJdXJRjO ZBlexVX7SwYa4m12YtpE20epxsc6/4DC7w5q/vKgrkLAjb4IpfSrevOcC8JJ8Hle3S Qyl/O/mw4bQKzKmd496ITKNgLpw+6C7Ofsf165HM= Date: Sun, 26 May 2019 18:35:45 +0100 From: Jonathan Cameron To: Eddie James Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, joel@jms.id.au, lars@metafoo.de, knaack.h@gmx.de Subject: Re: [PATCH v4 3/3] iio: dps310: Add pressure sensing capability Message-ID: <20190526183545.268bde1d@archlinux> In-Reply-To: <1558404814-26078-4-git-send-email-eajames@linux.ibm.com> References: <1558404814-26078-1-git-send-email-eajames@linux.ibm.com> <1558404814-26078-4-git-send-email-eajames@linux.ibm.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Mon, 20 May 2019 21:13:34 -0500 Eddie James wrote: > The DPS310 supports measurement of pressure, so support that in the > driver. Use background measurement like the temperature sensing and > default to lowest precision and lowest measurement rate. >=20 > Signed-off-by: Eddie James > Acked-by: Jonathan Cameron Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > drivers/iio/pressure/dps310.c | 363 ++++++++++++++++++++++++++++++++++++= +++--- > 1 file changed, 337 insertions(+), 26 deletions(-) >=20 > diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c > index a093e3a..2c1943b 100644 > --- a/drivers/iio/pressure/dps310.c > +++ b/drivers/iio/pressure/dps310.c > @@ -11,11 +11,12 @@ > * c0 * 0.5 + c1 * T_raw / kT =C2=B0C > * > * TODO: > - * - Pressure sensor readings > * - Optionally support the FIFO > */ > =20 > #include > +#include > +#include > #include > #include > =20 > @@ -31,6 +32,8 @@ > #define DPS310_TMP_B1 0x04 > #define DPS310_TMP_B2 0x05 > #define DPS310_PRS_CFG 0x06 > +#define DPS310_PRS_RATE_BITS GENMASK(6, 4) > +#define DPS310_PRS_PRC_BITS GENMASK(3, 0) > #define DPS310_TMP_CFG 0x07 > #define DPS310_TMP_RATE_BITS GENMASK(6, 4) > #define DPS310_TMP_PRC_BITS GENMASK(3, 0) > @@ -83,6 +86,8 @@ struct dps310_data { > struct mutex lock; /* Lock for sequential HW access functions */ > =20 > s32 c0, c1; > + s32 c00, c10, c20, c30, c01, c11, c21; > + s32 pressure_raw; > s32 temp_raw; > }; > =20 > @@ -93,33 +98,79 @@ struct dps310_data { > BIT(IIO_CHAN_INFO_SAMP_FREQ) | > BIT(IIO_CHAN_INFO_PROCESSED), > }, > + { > + .type =3D IIO_PRESSURE, > + .info_mask_separate =3D BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) | > + BIT(IIO_CHAN_INFO_SAMP_FREQ) | > + BIT(IIO_CHAN_INFO_PROCESSED), > + }, > }; > =20 > /* To be called after checking the COEF_RDY bit in MEAS_CFG */ > -static int dps310_get_temp_coef(struct dps310_data *data) > +static int dps310_get_coefs(struct dps310_data *data) > { > int rc; > - u8 coef[3]; > + u8 coef[18]; > u32 c0, c1; > + u32 c00, c10, c20, c30, c01, c11, c21; > =20 > - /* > - * Read temperature calibration coefficients c0 and c1 from the > - * COEF register. The numbers are 12-bit 2's compliment numbers > - */ > + /* Read all sensor calibration coefficients from the COEF registers. */ > rc =3D regmap_bulk_read(data->regmap, DPS310_COEF_BASE, coef, > sizeof(coef)); > if (rc < 0) > return rc; > =20 > + /* > + * Calculate temperature calibration coefficients c0 and c1. The > + * numbers are 12-bit 2's complement numbers. > + */ > c0 =3D (coef[0] << 4) | (coef[1] >> 4); > data->c0 =3D sign_extend32(c0, 11); > =20 > c1 =3D ((coef[1] & GENMASK(3, 0)) << 8) | coef[2]; > data->c1 =3D sign_extend32(c1, 11); > =20 > + /* > + * Calculate pressure calibration coefficients. c00 and c10 are 20 bit > + * 2's complement numbers, while the rest are 16 bit 2's complement > + * numbers. > + */ > + c00 =3D (coef[3] << 12) | (coef[4] << 4) | (coef[5] >> 4); > + data->c00 =3D sign_extend32(c00, 19); > + > + c10 =3D ((coef[5] & GENMASK(3, 0)) << 16) | (coef[6] << 8) | coef[7]; > + data->c10 =3D sign_extend32(c10, 19); > + > + c01 =3D (coef[8] << 8) | coef[9]; > + data->c01 =3D sign_extend32(c01, 15); > + > + c11 =3D (coef[10] << 8) | coef[11]; > + data->c11 =3D sign_extend32(c11, 15); > + > + c20 =3D (coef[12] << 8) | coef[13]; > + data->c20 =3D sign_extend32(c20, 15); > + > + c21 =3D (coef[14] << 8) | coef[15]; > + data->c21 =3D sign_extend32(c21, 15); > + > + c30 =3D (coef[16] << 8) | coef[17]; > + data->c30 =3D sign_extend32(c30, 15); > + > return 0; > } > =20 > +static int dps310_get_pres_precision(struct dps310_data *data) > +{ > + int rc; > + int val; > + > + rc =3D regmap_read(data->regmap, DPS310_PRS_CFG, &val); > + if (rc < 0) > + return rc; > + > + return BIT(val & GENMASK(2, 0)); > +} > + > static int dps310_get_temp_precision(struct dps310_data *data) > { > int rc; > @@ -137,6 +188,25 @@ static int dps310_get_temp_precision(struct dps310_d= ata *data) > } > =20 > /* Called with lock held */ > +static int dps310_set_pres_precision(struct dps310_data *data, int val) > +{ > + int rc; > + u8 shift_en; > + > + if (val < 0 || val > 128) > + return -EINVAL; > + > + shift_en =3D val >=3D 16 ? DPS310_PRS_SHIFT_EN : 0; > + rc =3D regmap_write_bits(data->regmap, DPS310_CFG_REG, > + DPS310_PRS_SHIFT_EN, shift_en); > + if (rc) > + return rc; > + > + return regmap_update_bits(data->regmap, DPS310_PRS_CFG, > + DPS310_PRS_PRC_BITS, ilog2(val)); > +} > + > +/* Called with lock held */ > static int dps310_set_temp_precision(struct dps310_data *data, int val) > { > int rc; > @@ -156,6 +226,20 @@ static int dps310_set_temp_precision(struct dps310_d= ata *data, int val) > } > =20 > /* Called with lock held */ > +static int dps310_set_pres_samp_freq(struct dps310_data *data, int freq) > +{ > + u8 val; > + > + if (freq < 0 || freq > 128) > + return -EINVAL; > + > + val =3D ilog2(freq) << 4; > + > + return regmap_update_bits(data->regmap, DPS310_PRS_CFG, > + DPS310_PRS_RATE_BITS, val); > +} > + > +/* Called with lock held */ > static int dps310_set_temp_samp_freq(struct dps310_data *data, int freq) > { > u8 val; > @@ -169,6 +253,18 @@ static int dps310_set_temp_samp_freq(struct dps310_d= ata *data, int freq) > DPS310_TMP_RATE_BITS, val); > } > =20 > +static int dps310_get_pres_samp_freq(struct dps310_data *data) > +{ > + int rc; > + int val; > + > + rc =3D regmap_read(data->regmap, DPS310_PRS_CFG, &val); > + if (rc < 0) > + return rc; > + > + return BIT((val & DPS310_PRS_RATE_BITS) >> 4); > +} > + > static int dps310_get_temp_samp_freq(struct dps310_data *data) > { > int rc; > @@ -181,6 +277,16 @@ static int dps310_get_temp_samp_freq(struct dps310_d= ata *data) > return BIT((val & DPS310_TMP_RATE_BITS) >> 4); > } > =20 > +static int dps310_get_pres_k(struct dps310_data *data) > +{ > + int rc =3D dps310_get_pres_precision(data); > + > + if (rc < 0) > + return rc; > + > + return scale_factors[ilog2(rc)]; > +} > + > static int dps310_get_temp_k(struct dps310_data *data) > { > int rc =3D dps310_get_temp_precision(data); > @@ -191,7 +297,7 @@ static int dps310_get_temp_k(struct dps310_data *data) > return scale_factors[ilog2(rc)]; > } > =20 > -static int dps310_read_temp(struct dps310_data *data) > +static int dps310_read_pres_raw(struct dps310_data *data) > { > int rc; > int rate; > @@ -203,23 +309,67 @@ static int dps310_read_temp(struct dps310_data *dat= a) > if (mutex_lock_interruptible(&data->lock)) > return -EINTR; > =20 > - rate =3D dps310_get_temp_samp_freq(data); > + rate =3D dps310_get_pres_samp_freq(data); > timeout =3D DPS310_POLL_TIMEOUT_US(rate); > =20 > /* Poll for sensor readiness; base the timeout upon the sample rate. */ > rc =3D regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, > - ready & DPS310_TMP_RDY, > + ready & DPS310_PRS_RDY, > DPS310_POLL_SLEEP_US(timeout), timeout); > + if (rc) > + goto done; > + > + rc =3D regmap_bulk_read(data->regmap, DPS310_PRS_BASE, val, sizeof(val)= ); > if (rc < 0) > goto done; > =20 > + raw =3D (val[0] << 16) | (val[1] << 8) | val[2]; > + data->pressure_raw =3D sign_extend32(raw, 23); > + > +done: > + mutex_unlock(&data->lock); > + return rc; > +} > + > +/* Called with lock held */ > +static int dps310_read_temp_ready(struct dps310_data *data) > +{ > + int rc; > + u8 val[3]; > + s32 raw; > + > rc =3D regmap_bulk_read(data->regmap, DPS310_TMP_BASE, val, sizeof(val)= ); > if (rc < 0) > - goto done; > + return rc; > =20 > raw =3D (val[0] << 16) | (val[1] << 8) | val[2]; > data->temp_raw =3D sign_extend32(raw, 23); > =20 > + return 0; > +} > + > +static int dps310_read_temp_raw(struct dps310_data *data) > +{ > + int rc; > + int rate; > + int ready; > + int timeout; > + > + if (mutex_lock_interruptible(&data->lock)) > + return -EINTR; > + > + rate =3D dps310_get_temp_samp_freq(data); > + timeout =3D DPS310_POLL_TIMEOUT_US(rate); > + > + /* Poll for sensor readiness; base the timeout upon the sample rate. */ > + rc =3D regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, > + ready & DPS310_TMP_RDY, > + DPS310_POLL_SLEEP_US(timeout), timeout); > + if (rc < 0) > + goto done; > + > + rc =3D dps310_read_temp_ready(data); > + > done: > mutex_unlock(&data->lock); > return rc; > @@ -267,19 +417,40 @@ static int dps310_write_raw(struct iio_dev *iio, > int rc; > struct dps310_data *data =3D iio_priv(iio); > =20 > - if (chan->type !=3D IIO_TEMP) > - return -EINVAL; > - > if (mutex_lock_interruptible(&data->lock)) > return -EINTR; > =20 > switch (mask) { > case IIO_CHAN_INFO_SAMP_FREQ: > - rc =3D dps310_set_temp_samp_freq(data, val); > + switch (chan->type) { > + case IIO_PRESSURE: > + rc =3D dps310_set_pres_samp_freq(data, val); > + break; > + > + case IIO_TEMP: > + rc =3D dps310_set_temp_samp_freq(data, val); > + break; > + > + default: > + rc =3D -EINVAL; > + break; > + } > break; > =20 > case IIO_CHAN_INFO_OVERSAMPLING_RATIO: > - rc =3D dps310_set_temp_precision(data, val); > + switch (chan->type) { > + case IIO_PRESSURE: > + rc =3D dps310_set_pres_precision(data, val); > + break; > + > + case IIO_TEMP: > + rc =3D dps310_set_temp_precision(data, val); > + break; > + > + default: > + rc =3D -EINVAL; > + break; > + } > break; > =20 > default: > @@ -291,6 +462,124 @@ static int dps310_write_raw(struct iio_dev *iio, > return rc; > } > =20 > +static int dps310_calculate_pressure(struct dps310_data *data) > +{ > + int i; > + int rc; > + int t_ready; > + int kpi =3D dps310_get_pres_k(data); > + int kti =3D dps310_get_temp_k(data); > + s64 rem =3D 0ULL; > + s64 pressure =3D 0ULL; > + s64 p; > + s64 t; > + s64 denoms[7]; > + s64 nums[7]; > + s64 rems[7]; > + s64 kp; > + s64 kt; > + > + if (kpi < 0) > + return kpi; > + > + if (kti < 0) > + return kti; > + > + kp =3D (s64)kpi; > + kt =3D (s64)kti; > + > + /* Refresh temp if it's ready, otherwise just use the latest value */ > + if (mutex_trylock(&data->lock)) { > + rc =3D regmap_read(data->regmap, DPS310_MEAS_CFG, &t_ready); > + if (rc >=3D 0 && t_ready & DPS310_TMP_RDY) > + dps310_read_temp_ready(data); > + > + mutex_unlock(&data->lock); > + } > + > + p =3D (s64)data->pressure_raw; > + t =3D (s64)data->temp_raw; > + > + /* Section 4.9.1 of the DPS310 spec; algebra'd to avoid underflow */ > + nums[0] =3D (s64)data->c00; > + denoms[0] =3D 1LL; > + nums[1] =3D p * (s64)data->c10; > + denoms[1] =3D kp; > + nums[2] =3D p * p * (s64)data->c20; > + denoms[2] =3D kp * kp; > + nums[3] =3D p * p * p * (s64)data->c30; > + denoms[3] =3D kp * kp * kp; > + nums[4] =3D t * (s64)data->c01; > + denoms[4] =3D kt; > + nums[5] =3D t * p * (s64)data->c11; > + denoms[5] =3D kp * kt; > + nums[6] =3D t * p * p * (s64)data->c21; > + denoms[6] =3D kp * kp * kt; > + > + /* Kernel lacks a div64_s64_rem function; denoms are all positive */ > + for (i =3D 0; i < 7; ++i) { > + u64 irem; > + > + if (nums[i] < 0LL) { > + pressure -=3D div64_u64_rem(-nums[i], denoms[i], &irem); > + rems[i] =3D -irem; > + } else { > + pressure +=3D div64_u64_rem(nums[i], denoms[i], &irem); > + rems[i] =3D (s64)irem; > + } > + } > + > + /* Increase precision and calculate the remainder sum */ > + for (i =3D 0; i < 7; ++i) > + rem +=3D div64_s64((s64)rems[i] * 1000000000LL, denoms[i]); > + > + pressure +=3D div_s64(rem, 1000000000LL); > + if (pressure < 0LL) > + return -ERANGE; > + > + return (int)min_t(s64, pressure, INT_MAX); > +} > + > +static int dps310_read_pressure(struct dps310_data *data, int *val, int = *val2, > + long mask) > +{ > + int rc; > + > + switch (mask) { > + case IIO_CHAN_INFO_SAMP_FREQ: > + rc =3D dps310_get_pres_samp_freq(data); > + if (rc < 0) > + return rc; > + > + *val =3D rc; > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_PROCESSED: > + rc =3D dps310_read_pres_raw(data); > + if (rc) > + return rc; > + > + rc =3D dps310_calculate_pressure(data); > + if (rc < 0) > + return rc; > + > + *val =3D rc; > + *val2 =3D 1000; /* Convert Pa to KPa per IIO ABI */ > + return IIO_VAL_FRACTIONAL; > + > + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: > + rc =3D dps310_get_pres_precision(data); > + if (rc < 0) > + return rc; > + > + *val =3D rc; > + return IIO_VAL_INT; > + > + default: > + return -EINVAL; > + } > +} > + > static int dps310_calculate_temp(struct dps310_data *data) > { > s64 c0; > @@ -310,11 +599,9 @@ static int dps310_calculate_temp(struct dps310_data = *data) > return (int)div_s64(t * 1000LL, kt); > } > =20 > -static int dps310_read_raw(struct iio_dev *iio, > - struct iio_chan_spec const *chan, > - int *val, int *val2, long mask) > +static int dps310_read_temp(struct dps310_data *data, int *val, int *val= 2, > + long mask) > { > - struct dps310_data *data =3D iio_priv(iio); > int rc; > =20 > switch (mask) { > @@ -327,7 +614,7 @@ static int dps310_read_raw(struct iio_dev *iio, > return IIO_VAL_INT; > =20 > case IIO_CHAN_INFO_PROCESSED: > - rc =3D dps310_read_temp(data); > + rc =3D dps310_read_temp_raw(data); > if (rc) > return rc; > =20 > @@ -351,6 +638,24 @@ static int dps310_read_raw(struct iio_dev *iio, > } > } > =20 > +static int dps310_read_raw(struct iio_dev *iio, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct dps310_data *data =3D iio_priv(iio); > + > + switch (chan->type) { > + case IIO_PRESSURE: > + return dps310_read_pressure(data, val, val2, mask); > + > + case IIO_TEMP: > + return dps310_read_temp(data, val, val2, mask); > + > + default: > + return -EINVAL; > + } > +} > + > static void dps310_reset(void *action_data) > { > struct dps310_data *data =3D action_data; > @@ -444,6 +749,12 @@ static int dps310_probe(struct i2c_client *client, > return rc; > =20 > /* > + * Set up pressure sensor in single sample, one measurement per second > + * mode > + */ > + rc =3D regmap_write(data->regmap, DPS310_PRS_CFG, 0); > + > + /* > * Set up external (MEMS) temperature sensor in single sample, one > * measurement per second mode > */ > @@ -451,9 +762,9 @@ static int dps310_probe(struct i2c_client *client, > if (rc < 0) > return rc; > =20 > - /* Temp shift is disabled when PRC <=3D 8 */ > + /* Temp and pressure shifts are disabled when PRC <=3D 8 */ > rc =3D regmap_write_bits(data->regmap, DPS310_CFG_REG, > - DPS310_TMP_SHIFT_EN, 0); > + DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0); > if (rc < 0) > return rc; > =20 > @@ -463,9 +774,9 @@ static int dps310_probe(struct i2c_client *client, > if (rc < 0) > return rc; > =20 > - /* Turn on temperature measurement in the background */ > + /* Turn on temperature and pressure measurement in the background */ > rc =3D regmap_write_bits(data->regmap, DPS310_MEAS_CFG, > - DPS310_MEAS_CTRL_BITS, > + DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN | > DPS310_TEMP_EN | DPS310_BACKGROUND); > if (rc < 0) > return rc; > @@ -479,7 +790,7 @@ static int dps310_probe(struct i2c_client *client, > if (rc < 0) > return rc; > =20 > - rc =3D dps310_get_temp_coef(data); > + rc =3D dps310_get_coefs(data); > if (rc < 0) > return rc; > =20