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. Thanks, Ivan -----Original Message----- From: Mika Westerberg [mailto:mika.westerberg@xxxxxxxxxxxxxxx] Sent: Wednesday, December 23, 2015 18:10 To: Zheng, Ivan Cc: Xue, Ken; wsa@xxxxxxxxxxxxx; Suthikulpanit, Suravee; Loc Ho; rjw@xxxxxxxxxxxxx; lenb@xxxxxxxxxx; linux-i2c@xxxxxxxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; jcm@xxxxxxxxxx; patches@xxxxxxx; 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. -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
