[PATCH v2 0/2] i2c:dw: Add APM X-Gene ACPI I2C device support

Zheng, Ivan Ivan.Zheng at amd.com
Wed Dec 23 03:24:44 PST 2015

Thanks Mika for the background.

I'm a BIOS engineer and my point is that such non-ACPI defined methods rely on BIOS implementation, so how the generic I2C driver works on a platform without such methods? Should the vendor implement their own driver in such case?

I think Windows driver use ConnectionSpeed field in I2CSerialBus declaration for a certain device and it's defined in ACPI 5.0.


-----Original Message-----
From: Mika Westerberg [mailto:mika.westerberg at linux.intel.com] 
Sent: Wednesday, December 23, 2015 18:10
To: Zheng, Ivan
Cc: Xue, Ken; wsa at the-dreams.de; Suthikulpanit, Suravee; Loc Ho; rjw at rjwysocki.net; lenb at kernel.org; linux-i2c at vger.kernel.org; linux-acpi at vger.kernel.org; linux-arm-kernel at lists.infradead.org; jcm at redhat.com; patches at apm.com; Hurwitz, Sherry; Duran, Leo; Hanjun Guo; Al Stone; Yu, Xiangliang
Subject: Re: [PATCH v2 0/2] i2c:dw: Add APM X-Gene ACPI I2C device support

On Wed, Dec 23, 2015 at 10:02:04AM +0000, Zheng, Ivan wrote:
> Why/how can Linux driver make use of such non-ACPI defined methods?

What do you mean exactly?

I added support for these (well, SSCN and FMCN) because I found out that some vendors include such methods with their BIOS implementation.
Windows driver uses these if present and so do we.

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