> 1. Do we need any modification in the BIOS for adding support of I2C,
> SPI slave devices to Linux using ACPI ?
Yes, you need to add the slave device info like slave address, speed
addressing mode, IRQ in the BIOS DSDT table.
> 2. Do we need to add the CONFIG_ACPI code (described in "I2C serial
> bus support" section of acpi/enumeration.txt) to the
> drivers/media/i2c/adv7180.c file ?
Yes...the ACPI ID shall match with the one that you added into the BIOS DSDT
table.
> 3. Where we need to add the device info like I2C bus number, I2C slave
> address, IRQ ?
In the BIOS DSDT table...using I2CSerialBus() resource descriptor to add
the slave device info. You can refer to ACPI spec for the details of
I2CSerialBus() resource descriptor.
> 4. Do we need to add any additional code in the chip driver
> specifically for this ACPI support ?
Yes, refer to the "I2C serial bus support" section of acpi/enumeration.txt.
> 5. We have an Intel reference board. The source code provided by Intel
> itself used certain board files to add support for SPI slave devices,
> Clock setup, Init, etc. Why it has been done without using ACPI ? Is it due
> to any restriction ?
The board file is only needed if you are using PCI enumeration mode.
> -----Original Message-----
> From: Ong, Boon Leong
> Sent: Wednesday, April 16, 2014 7:32 AM
> To: Sathish Kumar Balasubramaniam -ERS, HCL Tech
> Cc: linux-yocto@yoctoproject.org; Darren Hart (dvh...@linux.intel.com); Chang,
> Rebecca Swee Fun; Chew, Chiau Ee
> Subject: RE: [linux-yocto] Regarding clarifications for adding support of
> I2C, SPI
> slave devices on x86 through ACPI
>
> > -----Original Message-----
> > From: Sathish Kumar Balasubramaniam -ERS, HCL Tech [mailto:b-
> > sathishku...@hcl.com]
> > Sent: Wednesday, April 16, 2014 4:45 AM
> > To: Ong, Boon Leong
> > Cc: linux-yocto@yoctoproject.org; Darren Hart
> > (dvh...@linux.intel.com); Chang, Rebecca Swee Fun; Chew, Chiau Ee
> > Subject: RE: [linux-yocto] Regarding clarifications for adding support
> > of I2C, SPI slave devices on x86 through ACPI
> >
> > I could see addition of board files for baytrail in the git link you sent.
> >
> > By doubt is, why board files are still used in intel while the intel
> > community itself does not recommend board files.
> >
> It is needed only in PCI enumeration. It is largely due to the clock framework
> used by dma, spi & pwm which requires clock information to be
> available/registered with the clock during PCI enumeration. This is not needed
> for ACPI mode.
>
> > I am referring
> > http://events.linuxfoundation.org/sites/events/files/slides/x86-
> > platform.pdf
> >
> > Correct me if i am wrong ?
> >
> Yes. The view/opinion of not having board file still stay.
>
> > Regards,
> > B.Sathish Kumar
> > ________________________________________
> > From: Ong, Boon Leong [boon.leong....@intel.com]
> > Sent: 15 April 2014 20:28:14
> > To: Sathish Kumar Balasubramaniam -ERS, HCL Tech
> > Cc: linux-yocto@yoctoproject.org; Darren Hart
> > (dvh...@linux.intel.com);
> > Chang, Rebecca Swee Fun; Chew, Chiau Ee
> > Subject: RE: [linux-yocto] Regarding clarifications for adding support
> > of I2C, SPI slave devices on x86 through ACPI
> >
> > CC'ed Rebecca & Chia Ee for their response/attention.
> >
> > Short answer, we have both ACPI and PCI enumeration support for those
> > low power IO like I2C, SPI, HS-UART.
> > You can refer to
> > http://git.yoctoproject.org/cgit/cgit.cgi/linux-yocto-
> > 3.8/tree/meta/cfg/kernel-cache/features/valleyisland-io?h=meta for v3.8.
> >
> > For your knowledge, we are in the midst of making support for v3.10
> > too and we prefer that your long term goal is to converge into Linux
> > LTS/LTSI. But, it is fine to try out v3.8 and eventually move to v3.10.
> >
> >
> > From: linux-yocto-boun...@yoctoproject.org [mailto:linux-yocto-
> > boun...@yoctoproject.org] On Behalf Of Sathish Kumar Balasubramaniam
> > -ERS, HCL Tech
> > Sent: Tuesday, April 15, 2014 10:41 PM
> > To: linux-yocto@yoctoproject.org; Darren Hart (dvh...@linux.intel.com)
> > Subject: [linux-yocto] Regarding clarifications for adding support of
> > I2C, SPI slave devices on x86 through ACPI
> > Importance: High
> >
> > Hi,
> >
> > For Intel, I can understand that the community is advising to
> > implement the I2C, SPI slave devices info like base address, IRQs, etc
> > through ACPI mechanism rather than using Board files and FDT
> >
> > I read the following
> > https://www.kernel.org/doc/Documentation/acpi/enumeration.txt
> > https://events.linuxfoundation.org/images/stories/slides/lfcs2013_wyso
> > cki.pdf
> >
> > In Linux Kernel 3.8 we are trying to add support for (I2C, SPI) slave
> > devices like video output decoder, video input decoder, etc which are
> > behind the bus controllers
> >
> > For ex, for adding support of ADV7180 through I2C
> >
> > I have the following clarifications
> >
> > 1. Do we need any modification in the BIOS for adding support of I2C,
> > SPI slave devices to Linux using ACPI ?
> > 2. Do we need to add the CONFIG_ACPI code (described in "I2C serial
> > bus support" section of acpi/enumeration.txt) to the
> > drivers/media/i2c/adv7180.c file ?
> > 3. Where we need to add the device info like I2C bus number, I2C slave
> > address, IRQ ?
> > 4. Do we need to add any additional code in the chip driver
> > specifically for this ACPI support ?
> > 5. We have an Intel reference board. The source code provided by Intel
> > itself used certain board files to add support for SPI slave devices,
> > Clock setup, Init, etc. Why it has been done without using ACPI ? Is it due
> > to
> any restriction ?
> >
> >
> > Thanks,
> > B.Sathish Kumar
> >
> >
> > ::DISCLAIMER::
> > ----------------------------------------------------------------------
> > --------------------------------
> > ----------------------------------------------
> >
> > The contents of this e-mail and any attachment(s) are confidential and
> > intended for the named recipient(s) only.
> > E-mail transmission is not guaranteed to be secure or error-free as
> > information could be intercepted, corrupted, lost, destroyed, arrive
> > late or incomplete, or may contain viruses in transmission. The e mail
> > and its contents (with or without referred errors) shall therefore not
> > attach any liability on the originator or HCL or its affiliates.
> > Views or opinions, if any, presented in this email are solely those of
> > the author and may not necessarily reflect the views or opinions of
> > HCL or its affiliates. Any form of reproduction, dissemination,
> > copying, disclosure, modification, distribution and / or publication
> > of this message without the prior written consent of authorized
> > representative of HCL is strictly prohibited. If you have received this
> > email in
> error please delete it and notify the sender immediately.
> > Before opening any email and/or attachments, please check them for
> > viruses and other defects.
> >
> > ----------------------------------------------------------------------
> > --------------------------------
> > ----------------------------------------------
--
_______________________________________________
linux-yocto mailing list
linux-yocto@yoctoproject.org
https://lists.yoctoproject.org/listinfo/linux-yocto
