Re: Intel Atom I2C

[Imre Vadasz]

Hi,

On 07:05 Tue 21 Jun , Lundberg, Johannes wrote:
> Hi Imre
> 
> Thanks for the info! May I ask, isn't your system UEFI, same as mine? Last
> I tried DragonFly didn't support UEFI...

Yes, the HP x2 210 is UEFI only, but DragonFly *can* boot from UEFI :)
I did a port of FreeBSD's UEFI bootloader to DragonFly, which I commited
ca. 2 months ago, and I added basic support in the kernel for UEFI booting.
Only UEFI support in DragonFly's installer is still missing :(

> 
> I also had hangs when probing certain I2C controller (maybe it was the
> 7th...)
> 
> Perhaps using linuxkpi and the linux driver would be a good option for
> this. i915 uses I2C and it works with basically unmodified Intel source
> code. Or maybe I try to port your efforts later :)

It's not really an option here, to use the linux driver, since this I2c
bus has to integrate tightly with the operating-system for the ACPI
operation region handling, and the I2cSerialBus resource handling.

> On Tue, Jun 21, 2016 at 7:00 AM, Imre Vadasz  wrote:
> 
> > So autodetection via smbus(4) probably shouldn't be used at all for this
> > kind of I2c/smbus.
> > On my HP x2 210 Cherryview tablet it even causes the system to hard freeze,
> > when running the autodetection on the 7th I2C controller.
> >
> > Imre
> >
> 
> -- 
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> 秘密保持について：この電子メールは、名宛人に送信したものであり、秘匿特権の対象となる情報を含んでいます。
> もし、名宛人以外の方が受信された場合、このメールの破棄、およびこのメールに関する一切の開示、
> 複写、配布、その他の利用、または記載内容に基づくいかなる行動もされないようお願い申し上げます。
> ---
> CONFIDENTIALITY NOTE: The information in this email is confidential
> and intended solely for the addressee.
> Disclosure, copying, distribution or any other action of use of this
> email by person other than intended recipient, is prohibited.
> If you are not the intended recipient and have received this email in
> error, please destroy the original message.
___
freebsd-current@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-current
To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"

Re: Intel Atom I2C

[Lundberg, Johannes]

Hi Imre

Thanks for the info! May I ask, isn't your system UEFI, same as mine? Last
I tried DragonFly didn't support UEFI...

I also had hangs when probing certain I2C controller (maybe it was the
7th...)

Perhaps using linuxkpi and the linux driver would be a good option for
this. i915 uses I2C and it works with basically unmodified Intel source
code. Or maybe I try to port your efforts later :)


On Tue, Jun 21, 2016 at 7:00 AM, Imre Vadasz  wrote:

> So autodetection via smbus(4) probably shouldn't be used at all for this
> kind of I2c/smbus.
> On my HP x2 210 Cherryview tablet it even causes the system to hard freeze,
> when running the autodetection on the 7th I2C controller.
>
> Imre
>

-- 
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
秘密保持について：この電子メールは、名宛人に送信したものであり、秘匿特権の対象となる情報を含んでいます。
もし、名宛人以外の方が受信された場合、このメールの破棄、およびこのメールに関する一切の開示、
複写、配布、その他の利用、または記載内容に基づくいかなる行動もされないようお願い申し上げます。
---
CONFIDENTIALITY NOTE: The information in this email is confidential
and intended solely for the addressee.
Disclosure, copying, distribution or any other action of use of this
email by person other than intended recipient, is prohibited.
If you are not the intended recipient and have received this email in
error, please destroy the original message.
___
freebsd-current@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-current
To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"

Re: Intel Atom I2C

[Imre Vadasz]

So autodetection via smbus(4) probably shouldn't be used at all for this
kind of I2c/smbus.
On my HP x2 210 Cherryview tablet it even causes the system to hard freeze,
when running the autodetection on the 7th I2C controller.

Imre
___
freebsd-current@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-current
To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"

Re: Intel Atom I2C

[Imre Vadasz]

Hi,

No driver for the DMA controller is needed for using the I2C controllers.
On many devices the I2C controllers are only mapped as ACPI devices, and
not as PCI-devices, but the existing ichiic driver can trivially be
adapted to attach via acpi, which is already done by DragonFly's ichiic:
https://gitweb.dragonflybsd.org/dragonfly.git/blob/HEAD:/sys/bus/smbus/ichiic/ig4_acpi.c


On many Cherryview devices, the I2C controller driver needs to install a
handler for ACPI accesses to I2cSerialBus fields inside of GenericSerialBus
operation regions.
I have already committed the I2cSerialBus operation region Field handling to
DraognFly master (implemented by the smbacpi(4) driver which attaches as a
child to ichiic:
  
https://gitweb.dragonflybsd.org/dragonfly.git/blob/HEAD:/sys/bus/smbus/smbacpi/smbacpi.c)

The I2cSerialBus operation region Field handling is e.g. needed on the
HP X2 210 tablet/detachable for the AC adapter and ACPI battery devices,
as well as for activating power on the external micro-sd card slot via
the sdhc controller's _PS0 ACPI-method.


Peripheral devices hanging on the I2c busses usually are detected as ACPI
devices, which have I2cSerialBus resource entries.
On current Cherryview devices the I2c peripheral devices usually aren't
explicitly child devices of the I2c-Controller devices, but the
I2cSerialBus resources contain a string which can be dereferenced to get
the corresponding I2c-bus device.
The same mechanism is used for mapping GPIO pins and GPIO interrupts
(with the GpioInt and GpioIo resource entries).

Also, since the I2c peripheral devices usually are no longer children of
the I2c-bus, the correct device attachement/initialization order needs to
be derived via the _DEP acpi methods.
___
freebsd-current@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-current
To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"

Re: Intel Atom I2C

[Lundberg, Johannes]

Hi Ian

Thanks for the info. I'll give it a try and see if I have more success.

I'm still uncertain about the role of the DMA controller though. If data
has to be relayed through it or if using it is optional..

Maybe some further testing will reveal the truth..

On Sunday, June 19, 2016, Ian Lepore  wrote:

> On Sun, 2016-06-19 at 11:36 -0700, Lundberg, Johannes wrote:
> > Hi
> >
> > I am trying to figure out how to get I2C support on Intel Atom x5
> > (Cherryview), which should be same for Baytrail platforms.
> >
> > On the Serial I/O device (PCI device 24) there are 8 devices.
> > #0 is DMA controller
> > #1-7 are I2C controllers (1 & 2 available on GPIO pins).
> >
> > I assume that all traffic to/from the I2C controllers must go via the
> > DMA
> > controller although I'm not 100% sure.
> >
> > In page 23 in the atom-z8000-datasheet-vol-2 there is a nice table of
> > the
> > PCI configuration space.
> >
> > On Linux they have
> > i2c/busses/i2c-designware-*
> > and
> > dma/dw/*
> > that takes care of the I2C and DMA parts.
> >
> > The ichiic (ig4) driver seems to be working on this platform and
> > looking
> > through the registers it seems to be basically the same as i2c
> > -designware
> > driver, but it doesn't not detect any devices on the I2C bus
> > (/dev/smbx).
> > (I have confirmed that the devices are recognized on Linux on the
> > same
> > device.)
> >
>
> There is no way to automatically detect devices on an i2c bus.  You
> can, with some incomplete success, detect which addresses are in use.
>  Even when you can detect there is a device at a given address, there
> is no way to figure out what that device is (and in some rare cases,
> even probing for the address being in use can perturb the device).
>
> So, in the linux case, something must be telling the OS which drivers
> to attach to which addresses.  I have no idea what that mechanism might
> be, if it's not FDT.
>
> In freebsd, you can specify i2c devices using FDT data, or hints.
>
> -- Ian
>
> > We also need a Mailbox (IOSF-SB MBI) driver and it is quite simple so
> > I
> > have already ported this.
> >
> > What is left to do I guess would be to implement a DMA driver that
> > works
> > with ig4 or create a new ig4 driver that is extended to use the DMA
> > controller, and implement the DMA controller driver.
> >
> > Implementing from scratch would be quite the undertaking. Can we
> > leverage
> > any existing DMA infrastructure for this?
> >
> > Any one interested in helping?
> >
> > I have a board called "UP" which is very similar to Raspberry Pi but
> > Intel
> > SoC. It has IC20 and IC21 available on the 40-pin connector.
> > Since it's Intel most stuff just works. Thanks to mmacy accelerated
> > graphics is also working (on separate branch).
> > It really is a great board for anyone who likes to tinker :)
> >
> >
> > References:
> > http://www.up-board.org/
> > http://lxr.linux.no/#linux+v4.6.2/drivers/i2c/busses
> > http://lxr.linux.no/#linux+v4.6.2/drivers/dma/dw
> > http://www.intel.com/content/www/us/en/processors/atom/atom-z8000-dat
> > asheet-vol-1.html
> > http://www.intel.com/content/www/us/en/processors/atom/atom-z8000-dat
> > asheet-vol-2.html
> >
> > Other TODO stuff:
> > Port Imer's GPIO driver from DragonFly
> > Add support for S0ix sleep states (would be useful for all new Intel
> > low
> > power laptops since Haswell)
> > And more...
> >
> > Thanks!
> > /Johannes
> >
>


-- 
Sent from Gmail Mobile

-- 
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
秘密保持について：この電子メールは、名宛人に送信したものであり、秘匿特権の対象となる情報を含んでいます。
もし、名宛人以外の方が受信された場合、このメールの破棄、およびこのメールに関する一切の開示、
複写、配布、その他の利用、または記載内容に基づくいかなる行動もされないようお願い申し上げます。
---
CONFIDENTIALITY NOTE: The information in this email is confidential
and intended solely for the addressee.
Disclosure, copying, distribution or any other action of use of this
email by person other than intended recipient, is prohibited.
If you are not the intended recipient and have received this email in
error, please destroy the original message.
___
freebsd-current@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-current
To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"

Re: Intel Atom I2C

[Ian Lepore]

On Sun, 2016-06-19 at 11:36 -0700, Lundberg, Johannes wrote:
> Hi
> 
> I am trying to figure out how to get I2C support on Intel Atom x5
> (Cherryview), which should be same for Baytrail platforms.
> 
> On the Serial I/O device (PCI device 24) there are 8 devices.
> #0 is DMA controller
> #1-7 are I2C controllers (1 & 2 available on GPIO pins).
> 
> I assume that all traffic to/from the I2C controllers must go via the
> DMA
> controller although I'm not 100% sure.
> 
> In page 23 in the atom-z8000-datasheet-vol-2 there is a nice table of
> the
> PCI configuration space.
> 
> On Linux they have
> i2c/busses/i2c-designware-*
> and
> dma/dw/*
> that takes care of the I2C and DMA parts.
> 
> The ichiic (ig4) driver seems to be working on this platform and
> looking
> through the registers it seems to be basically the same as i2c
> -designware
> driver, but it doesn't not detect any devices on the I2C bus
> (/dev/smbx).
> (I have confirmed that the devices are recognized on Linux on the
> same
> device.)
> 

There is no way to automatically detect devices on an i2c bus.  You
can, with some incomplete success, detect which addresses are in use. 
 Even when you can detect there is a device at a given address, there
is no way to figure out what that device is (and in some rare cases,
even probing for the address being in use can perturb the device).

So, in the linux case, something must be telling the OS which drivers
to attach to which addresses.  I have no idea what that mechanism might
be, if it's not FDT.

In freebsd, you can specify i2c devices using FDT data, or hints.

-- Ian

> We also need a Mailbox (IOSF-SB MBI) driver and it is quite simple so
> I
> have already ported this.
> 
> What is left to do I guess would be to implement a DMA driver that
> works
> with ig4 or create a new ig4 driver that is extended to use the DMA
> controller, and implement the DMA controller driver.
> 
> Implementing from scratch would be quite the undertaking. Can we
> leverage
> any existing DMA infrastructure for this?
> 
> Any one interested in helping?
> 
> I have a board called "UP" which is very similar to Raspberry Pi but
> Intel
> SoC. It has IC20 and IC21 available on the 40-pin connector.
> Since it's Intel most stuff just works. Thanks to mmacy accelerated
> graphics is also working (on separate branch).
> It really is a great board for anyone who likes to tinker :)
> 
> 
> References:
> http://www.up-board.org/
> http://lxr.linux.no/#linux+v4.6.2/drivers/i2c/busses
> http://lxr.linux.no/#linux+v4.6.2/drivers/dma/dw
> http://www.intel.com/content/www/us/en/processors/atom/atom-z8000-dat
> asheet-vol-1.html
> http://www.intel.com/content/www/us/en/processors/atom/atom-z8000-dat
> asheet-vol-2.html
> 
> Other TODO stuff:
> Port Imer's GPIO driver from DragonFly
> Add support for S0ix sleep states (would be useful for all new Intel
> low
> power laptops since Haswell)
> And more...
> 
> Thanks!
> /Johannes
> 
___
freebsd-current@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-current
To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"

Intel Atom I2C

[Lundberg, Johannes]

Hi

I am trying to figure out how to get I2C support on Intel Atom x5
(Cherryview), which should be same for Baytrail platforms.

On the Serial I/O device (PCI device 24) there are 8 devices.
#0 is DMA controller
#1-7 are I2C controllers (1 & 2 available on GPIO pins).

I assume that all traffic to/from the I2C controllers must go via the DMA
controller although I'm not 100% sure.

In page 23 in the atom-z8000-datasheet-vol-2 there is a nice table of the
PCI configuration space.

On Linux they have
i2c/busses/i2c-designware-*
and
dma/dw/*
that takes care of the I2C and DMA parts.

The ichiic (ig4) driver seems to be working on this platform and looking
through the registers it seems to be basically the same as i2c-designware
driver, but it doesn't not detect any devices on the I2C bus (/dev/smbx).
(I have confirmed that the devices are recognized on Linux on the same
device.)

We also need a Mailbox (IOSF-SB MBI) driver and it is quite simple so I
have already ported this.

What is left to do I guess would be to implement a DMA driver that works
with ig4 or create a new ig4 driver that is extended to use the DMA
controller, and implement the DMA controller driver.

Implementing from scratch would be quite the undertaking. Can we leverage
any existing DMA infrastructure for this?

Any one interested in helping?

I have a board called "UP" which is very similar to Raspberry Pi but Intel
SoC. It has IC20 and IC21 available on the 40-pin connector.
Since it's Intel most stuff just works. Thanks to mmacy accelerated
graphics is also working (on separate branch).
It really is a great board for anyone who likes to tinker :)


References:
http://www.up-board.org/
http://lxr.linux.no/#linux+v4.6.2/drivers/i2c/busses
http://lxr.linux.no/#linux+v4.6.2/drivers/dma/dw
http://www.intel.com/content/www/us/en/processors/atom/atom-z8000-datasheet-vol-1.html
http://www.intel.com/content/www/us/en/processors/atom/atom-z8000-datasheet-vol-2.html

Other TODO stuff:
Port Imer's GPIO driver from DragonFly
Add support for S0ix sleep states (would be useful for all new Intel low
power laptops since Haswell)
And more...

Thanks!
/Johannes

-- 
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
秘密保持について：この電子メールは、名宛人に送信したものであり、秘匿特権の対象となる情報を含んでいます。
もし、名宛人以外の方が受信された場合、このメールの破棄、およびこのメールに関する一切の開示、
複写、配布、その他の利用、または記載内容に基づくいかなる行動もされないようお願い申し上げます。
---
CONFIDENTIALITY NOTE: The information in this email is confidential
and intended solely for the addressee.
Disclosure, copying, distribution or any other action of use of this
email by person other than intended recipient, is prohibited.
If you are not the intended recipient and have received this email in
error, please destroy the original message.
___
freebsd-current@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-current
To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"