Re: [PATCH v2 3/5] iio: accel: bma400: Add triggered buffer support

From: Jonathan Cameron <jic23@kernel.org>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Jagath Jog J <jagathjog1996@gmail.com>,
	Dan Robertson <dan@dlrobertson.com>,
	linux-iio <linux-iio@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 3/5] iio: accel: bma400: Add triggered buffer support
Date: Mon, 28 Mar 2022 18:02:12 +0100	[thread overview]
Message-ID: <20220328180212.0bac53fe@jic23-huawei> (raw)
In-Reply-To: <CAHp75Vdx3ZWFc9Xa7AhLGM=-4AzfamEqTkZxvBeu=Hu4KF7pSg@mail.gmail.com>

On Sun, 27 Mar 2022 22:45:16 +0300
Andy Shevchenko <andy.shevchenko@gmail.com> wrote:

> On Sat, Mar 26, 2022 at 9:41 PM Jagath Jog J <jagathjog1996@gmail.com> wrote:
> >
> > Added trigger buffer support to read continuous acceleration
> > data from device with data ready interrupt which is mapped
> > to INT1 pin.  
> 
> ...
> 
> > +       struct {  
> 
> > +               __le16 buff[3];  
> 
> In my (mostly review) practice it's rare that sensors operate in LE mode.
> Please, double check that.

Just for giggles, we've had sensors that had most channels little endian
but with one that was big endian...  Thankfully this isn't one of those.

I checked the datasheet and whilst indeed less common, these do appear to
be little endian.
https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bma400-ds000.pdf
page 50
ACC_X_LSB at address 0x04
ACC_X_MSB at address 0x05
> 
> > +               u8 temperature;
> > +               s64 ts __aligned(8);
> > +       } buffer ____cacheline_aligned;  
> 