From mboxrd@z Thu Jan 1 00:00:00 1970 From: Santi Villalba Date: Tue, 28 May 2013 10:30:57 +0000 Subject: Re: [lm-sensors] ITE IT8518E supported in coreboot, helpful? Message-Id: <51A48761.1070705@gmail.com> List-Id: References: <519F374B.3070101@gmail.com> In-Reply-To: <519F374B.3070101@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lm-sensors@vger.kernel.org On 27/05/13 18:17, Guenter Roeck wrote: > On Mon, May 27, 2013 at 07:10:13AM +0200, Santi Villalba wrote: >> Hi Guenter, >> >> On 24/05/13 19:34, Guenter Roeck wrote: >>> On Fri, May 24, 2013 at 11:47:55AM +0200, Santi Villalba wrote: >>>> This controller is giving people some trouble, as it is shipped in >>>> more and more laptops [1] and the fans can become quite annoying in >>>> these systems. >>>> >>>> In the past it was said that the main problem was the lack of a >>>> datasheet from ITE [2]. Recently there has been progress from the >>>> coreboot projects getting the info for quanta firmware on IT8518 >>>> [3]. Can this particular file help with the lack of specs or it >>>> depends on other factors? >>>> http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/ec/quanta/it8518/acpi/ec.asl;hu49fa283da69b9b1fca8589b1fc7f59fd30f7a4;hb~568559634199668859b7c662aea7f6b41f3920 >>>> >>> I may be missing something, but my understanding is that the chip >>> has an embedded microcontroller (EC) which handles the actual fan >>> control. While the chip data sheet describes the hardware accessible >>> to the EC, and the API between CPU and EC, it does not describe >>> the logical interface between the two. Problem is that this >>> interface is not well defined and depends on the microcode >>> running on the EC. >>> >>> The file referenced above seems to provide that information for the >>> specific board and for the microcode running on the EC in that board >>> (which appears to be the referenced 'quanta' firmware). That does >>> not mean, however, that it would be the same for other boards, >>> including yours. >>> >>> A second potential problem is that the ACPI data provided above suggests >>> that the EC may be controlled through ACPI, which means that ACPI most >>> likely reserves the memory space needed to access the controller. >>> If this is the case in your system, which is quite likely, your best >>> option would be an ACPI driver. >> That was my fearsome first guess. So I will look around a bit more >> to check if there is any spec available on the concrete EC firmware >> running clevo machines. If I find it I will try the ACPI driver >> route first. >> > I don't think you need the firmware spec if ACPI is used. All you need to do is > to decode the ACPI table, check which accessors it provides, and write a driver > using those accessors. [1] should help. I don't know much about ACPI, so I won't > be able to help much further. > > Looking through coreboot, there are lots of laptops using embedded controllers, > and for most if not all of them the access methods used are different. > > Guenter > > [1] http://smackerelofopinion.blogspot.com/2009/10/dumping-acpi-tables-using-acpidump-and.html This puts me in the right track, already looking at the ACPI table. Will take time but I will get there. Thanks again Santi _______________________________________________ lm-sensors mailing list lm-sensors@lm-sensors.org http://lists.lm-sensors.org/mailman/listinfo/lm-sensors