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=-7.1 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,URIBL_BLOCKED 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 BF31EC072A4 for ; Sat, 18 May 2019 10:43:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9015020C01 for ; Sat, 18 May 2019 10:43:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558176232; bh=FPuET957IVsJTVkL6+gB6VWuxqUetLWhiGUZNP9FBEU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=AjnsWzw76Rdxi4cxrKZCZMxvXMe16tiAPxLyVgAF+kbfPwsawXvjtZ/T8j1NGzrNo F/6ZPfcAJ/YiIqEggs9VmwYoA8OYW6/23wY5NFcib1sGMmvFBBheUfZwPMVchRKa+O 5X9edbzmaGmJeY8na5+z2t4l2YP4ewRClACttKv0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729719AbfERKnw (ORCPT ); Sat, 18 May 2019 06:43:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:49442 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726263AbfERKnv (ORCPT ); Sat, 18 May 2019 06:43:51 -0400 Received: from archlinux (cpc91196-cmbg18-2-0-cust659.5-4.cable.virginm.net [81.96.234.148]) (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 A234220872; Sat, 18 May 2019 10:43:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558176230; bh=FPuET957IVsJTVkL6+gB6VWuxqUetLWhiGUZNP9FBEU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=IaIEpyp1Lg1VQPtuUxCkq2/7AspYMgsg99m7+xJwuMdw+SOfp8vc1NSN+jI235byZ sBl4QVxIl23PSnaxJjOXourrrE+onhQNQM95/+IaRq0tXrkg9rXgRKFLI32zmp0/Cr +ogfW8gyCrft1wgtDuZjJJr47bdj0YsRj+kev+PI= Date: Sat, 18 May 2019 11:43:46 +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, Christopher Bostic Subject: Re: [PATCH v3 2/3] iio: dps310: Temperature measurement errata Message-ID: <20190518114346.51a54093@archlinux> In-Reply-To: <1557945677-12838-3-git-send-email-eajames@linux.ibm.com> References: <1557945677-12838-1-git-send-email-eajames@linux.ibm.com> <1557945677-12838-3-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=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 15 May 2019 13:41:16 -0500 Eddie James wrote: > From: Christopher Bostic > > Add a manufacturer's suggested workaround to deal with early revisions > of chip that don't indicate correct temperature. Readings can be in the > ~60C range when they should be in the ~20's. > > Signed-off-by: Christopher Bostic > Signed-off-by: Joel Stanley > Signed-off-by: Eddie James Looks fine to me. For reference: Acked-by: Jonathan Cameron > --- > drivers/iio/pressure/dps310.c | 52 +++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 50 insertions(+), 2 deletions(-) > > diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c > index 9acfccb..a093e3a 100644 > --- a/drivers/iio/pressure/dps310.c > +++ b/drivers/iio/pressure/dps310.c > @@ -53,7 +53,6 @@ > #define DPS310_RESET 0x0c > #define DPS310_RESET_MAGIC 0x09 > #define DPS310_COEF_BASE 0x10 > -#define DPS310_COEF_SRC 0x28 > > /* Make sure sleep time is <= 20ms for usleep_range */ > #define DPS310_POLL_SLEEP_US(t) min(20000, (t) / 8) > @@ -234,6 +233,10 @@ static bool dps310_is_writeable_reg(struct device *dev, unsigned int reg) > case DPS310_MEAS_CFG: > case DPS310_CFG_REG: > case DPS310_RESET: > + /* No documentation available on the registers below */ > + case 0x0e: > + case 0x0f: > + case 0x62: > return true; > default: > return false; > @@ -250,6 +253,7 @@ static bool dps310_is_volatile_reg(struct device *dev, unsigned int reg) > case DPS310_TMP_B1: > case DPS310_TMP_B2: > case DPS310_MEAS_CFG: > + case 0x32: /* No documentation available on this register */ > return true; > default: > return false; > @@ -360,7 +364,7 @@ static void dps310_reset(void *action_data) > .writeable_reg = dps310_is_writeable_reg, > .volatile_reg = dps310_is_volatile_reg, > .cache_type = REGCACHE_RBTREE, > - .max_register = DPS310_COEF_SRC, > + .max_register = 0x62, /* No documentation available on this register */ > }; > > static const struct iio_info dps310_info = { > @@ -368,6 +372,46 @@ static void dps310_reset(void *action_data) > .write_raw = dps310_write_raw, > }; > > +/* > + * Some verions of chip will read temperatures in the ~60C range when > + * its actually ~20C. This is the manufacturer recommended workaround > + * to correct the issue. The registers used below are undocumented. > + */ > +static int dps310_temp_workaround(struct dps310_data *data) > +{ > + int rc; > + int reg; > + > + rc = regmap_read(data->regmap, 0x32, ®); > + if (rc < 0) > + return rc; > + > + /* > + * If bit 1 is set then the device is okay, and the workaround does not > + * need to be applied > + */ > + if (reg & BIT(1)) > + return 0; > + > + rc = regmap_write(data->regmap, 0x0e, 0xA5); > + if (rc < 0) > + return rc; > + > + rc = regmap_write(data->regmap, 0x0f, 0x96); > + if (rc < 0) > + return rc; > + > + rc = regmap_write(data->regmap, 0x62, 0x02); > + if (rc < 0) > + return rc; > + > + rc = regmap_write(data->regmap, 0x0e, 0x00); > + if (rc < 0) > + return rc; > + > + return regmap_write(data->regmap, 0x0f, 0x00); > +} > + > static int dps310_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > @@ -439,6 +483,10 @@ static int dps310_probe(struct i2c_client *client, > if (rc < 0) > return rc; > > + rc = dps310_temp_workaround(data); > + if (rc < 0) > + return rc; > + > rc = devm_iio_device_register(&client->dev, iio); > if (rc) > return rc;