Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <0f86cf66a14b4d5900ddee68cd7b49807128b7e9.camel@gmail.com>
Subject: Re: [PATCH v2 3/5] iio: pressure: bmp280: Add support for new
 sensor BMP580
From:   Angel Iglesias <ang.iglesiasg@gmail.com>
To:     Jonathan Cameron <jic23@kernel.org>
Cc:     Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        ak@it-klinger.de, andriy.shevchenko@linux.intel.com,
        devicetree@vger.kernel.org, krzysztof.kozlowski+dt@linaro.org,
        lars@metafoo.de, linux-iio@vger.kernel.org,
        linux-kernel@vger.kernel.org, nikita.yoush@cogentembedded.com,
        paul@crapouillou.net, rafael.j.wysocki@intel.com,
        robh+dt@kernel.org, ulf.hansson@linaro.org
Date:   Sun, 01 Jan 2023 12:16:28 +0100
In-Reply-To: <20221230182253.45fcfdf4@jic23-huawei>
References: <cover.1672062380.git.ang.iglesiasg@gmail.com>
         <c053976f56c3810915ca2ead6c358b5997b782e5.1672062380.git.ang.iglesiasg@gmail.com>
         <d0e98b2d-1c00-b7cc-d0b3-4477e27cf822@wanadoo.fr>
         <8c4826ea5698e4e1b2910f5b01e66a41970a8053.camel@gmail.com>
         <20221230182253.45fcfdf4@jic23-huawei>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.46.2 (by Flathub.org) 
MIME-Version: 1.0
Precedence: bulk

On Fri, 2022-12-30 at 18:22 +0000, Jonathan Cameron wrote:
> On Thu, 29 Dec 2022 19:23:16 +0100
> Angel Iglesias <ang.iglesiasg@gmail.com> wrote:
>=20
> > On Thu, 2022-12-29 at 18:35 +0100, Christophe JAILLET wrote:
> > > Le 26/12/2022 =C3=A0 15:29, Angel Iglesias a =C3=A9crit=C2=A0:=C2=A0=
=20
> > > > Adds compatibility with the new sensor generation, the BMP580.
> > > >=20
> > > > The measurement and initialization codepaths are adapted from
> > > > the device datasheet and the repository from manufacturer at
> > > > https://github.com/boschsensortec/BMP5-Sensor-API.
> > > >=20
> > > > Signed-off-by: Angel Iglesias
> > > > <ang.iglesiasg-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> > > > =C2=A0=20
> > >=20
> > > [...]
> > > =C2=A0=20
> > > > diff --git a/drivers/iio/pressure/bmp280.h
> > > > b/drivers/iio/pressure/bmp280.h
> > > > index efc31bc84708..27d2abc17d01 100644
> > > > --- a/drivers/iio/pressure/bmp280.h
> > > > +++ b/drivers/iio/pressure/bmp280.h=C2=A0=20
> > >=20
> > > [...]
> > > =C2=A0=20
> > > > +#define BMP580_CHIP_ID=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A00x50
> > > > =C2=A0 #define BMP380_CHIP_ID=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A00x50=C2=A0=20
> > >=20
> > > Hi,
> > >=20
> > > this is maybe correct (I've not been able to find the datasheet to ch=
eck=20
> > > myself), but it looks odd to have the same ID for 2 different chips.=
=C2=A0=20
> >=20
> > Yes, I also couldn't find a datasheet for the BMP580 or a devkit anywhe=
re.
> > I'm
> > developing this using the BMP581, which seems to be a variant almost
> > identical.
> > Something similar happened with the BMP38x; you could find the BMP384 a=
nd
> > the
> > BMP388, but the BMP380 was unavailable everywhere, datasheet included. =
My
> > guess
> > is this is a similar situation. In any case, the datasheet of the BMP58=
1 is
> > available here:
> > https://www.bosch-sensortec.com/media/boschsensortec/downloads/datashee=
ts/bst-bmp581-ds004.pdf
> >=20
> > Regarding the chip id being the same between generations is weird, but =
at
> > least
> > the datasheet and the sensor I have uses 0x50 as the chip id. After you
> > mentioned this, I checked back on the reference API repository from Bos=
ch
> > and it
> > has both 0x50 and 0x51 as valid IDs:
> > *
> > https://github.com/boschsensortec/BMP5-Sensor-API/blob/master/bmp5_defs=
.h#L198
> > * https://github.com/boschsensortec/BMP5-Sensor-API/blob/master/bmp5.c#=
L1444
> https://github.com/boschsensortec/BMP3-Sensor-API/blob/master/bmp3_defs.h
> I was curious on whether we had a wrong value for bmp380, but nope... Sam=
e ID.
>=20
> Huh. As per earlier comment - who wants to moan at Bosch as this is crazy
> situation?
>=20
> Jonathan

Well I'm doing this in my free time beacuse I wanted to setup a meteo stati=
on
and got annoyed needing to patch-up userspace code for reading pressure and
temperature sensors on a very underpowered ARM device when there is a kerne=
l
subsystem for this kind of things. The rest is history on the mailing list.
I don't think I have any leverage to have Bosch listening to my complaints

Angel

>=20
> >=20
> > Angel
> >=20
> > > CJ
> > > =C2=A0=20
> > > > =C2=A0 #define BMP180_CHIP_ID=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A00x55
> > > > =C2=A0 #define BMP280_CHIP_ID=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A00x58=C2=A0=20
> > > =C2=A0=20
> >=20
>=20