Re: [PATCH v2] iio: accel: bmc150: Check for a second ACPI device for BOSC0200

From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Steven Presser <steve@pressers.name>
Cc: Hans de Goede <hdegoede@redhat.com>,
	Hartmut Knaack <knaack.h@gmx.de>,
	Jeremy Cline <jeremy@jcline.org>,
	Jonathan Cameron <Jonathan.Cameron@huawei.com>,
	Jonathan Cameron <jic23@jic23.retrosnub.co.uk>,
	Lars Kellogg-Stedman <lars@oddbit.com>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
	Wolfram Sang <wsa@the-dreams.de>,
	linux-iio@vger.kernel.org
Subject: Re: [PATCH v2] iio: accel: bmc150: Check for a second ACPI device for BOSC0200
Date: Tue, 6 Feb 2018 21:47:28 +0200	[thread overview]
Message-ID: <CAHp75VeKq0=+BvK=n09iufsOSuMgE3CtJCiWSqRMGM2dcOiJVQ@mail.gmail.com> (raw)
In-Reply-To: <9ee7da52-d86a-7784-8c00-6e5b4ae3ed96@pressers.name>

On Sun, Feb 4, 2018 at 7:58 PM, Steven Presser <steve@pressers.name> wrote:

> I had a chance to sit back down with the machine.  I didn't take it all the
> way apart - there are pieces that I'm afraid of breaking without directions
> on how to properly disassemble them.

No need I think to go so-o deep.

> However, I did recover an exact chip ID - the chips in use are BMA255s [1].
> Rather than take the machine apart (and because the chips are 2mmx2mm), I
> queried the chip over SMBus.  On page 50 of the below document, you can see
> that register 0x00 is a read-only chip ID.  This chipID is unique per Bosch
> product.  So, using SMBus, I asked the chip for it's chip ID (0xFA, in this
> case) and then searched likely products until I found the matching chipID.

Thanks!

> Does this suffice to settle which chips are in use?  If not, I can finish
> taking the machine apart, I'd just prefer to avoid the risk of breaking
> something.

I think it's pretty much enough.

> As soon as I finish screwing everything back together, I'll grab the other
> software IDs asked for and build the branch referenced elsewhere.

I'm just waiting for your Tested-by in case my patch series works as
expected before I send it out.

-- 
With Best Regards,
Andy Shevchenko