Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-10 Thread Hans de Goede
Hi,

On 4/10/21 8:56 AM, Guenter Roeck wrote:
> On 4/8/21 11:02 PM, Thomas Weißschuh wrote:
>> On Do, 2021-04-08T08:00-0700, Guenter Roeck wrote:
>>> On 4/8/21 2:36 AM, Hans de Goede wrote:
 On 4/7/21 9:43 PM, Thomas Weißschuh wrote:
> On Mi, 2021-04-07T17:54+0200, Hans de Goede wrote:
 Jean, Guenter,

 Thomas has been working on a WMI driver to expose various motherboard
 temperatures on a gigabyte board where the IO-addresses for the it87 chip
 are reserved by ACPI. We are discussing how best to deal with this, there
 are some ACPI methods to directly access the super-IO registers (with 
 locking
 to protect against other ACPI accesses). This reminded me of an idea I had
 a while ago to solve a similar issue with an other superIO chip, abstract
 the superIO register access-es using some reg_ops struct and allow an 
 ACPI/WMI
 driver to provide alternative reg_ops:
 https://bugzilla.kernel.org/show_bug.cgi?id=204807#c47

 Do you think this is a good idea (or a bad one)? And would something like 
 that
 be acceptable to you ?

>>>
>>> The upstream it87 driver is severely out of date. I had an out-of-tree 
>>> driver
>>> with various improvements which I didn't upstream, first because no one was 
>>> willing
>>> to review changes and then because it had deviated too much. I pulled it 
>>> from
>>> public view because I got pounded for not upstreaming it, because people 
>>> started
>>> demanding support (not asking, demanding) for it, and because Gigabyte 
>>> stopped
>>> providing datasheets for the more recent ITE chips and it became effectively
>>> unmaintainable.
>>>
>>> Some ITE chips have issues which can cause system hangs if accessed 
>>> directly.
>>> I put some work to remedy that into the non-upstream driver, but that was 
>>> all
>>> just guesswork. Gigabyte knows about the problem (or so I was told from 
>>> someone
>>> who has an NDA with them), but I didn't get them or ITE to even acknowledge 
>>> it
>>> to me. I even had a support case open with Gigabyte for a while, but all I 
>>> could
>>> get out of them is that they don't support Linux and what I would have to 
>>> reproduce
>>> the problem with Windows for them to provide assistance (even though, again,
>>> they knew about it).
>>>
>>> As for using ACPI locks or WMI to ensure that ACPI leaves the chip alone 
>>> while
>>> the driver accesses chips directly: That is an option, but it has (at least)
>>> two problems.
>>>
>>> First, ACPI access methods are not well documented or standardized. I had 
>>> tried
>>> to find useful means to do that some time ago, but I gave up because each 
>>> board
>>> (even from the same vendor) handles locking and accesses differently. We 
>>> would
>>> end up with lots of board specific code. Coincidentally, that was for ASUS 
>>> boards
>>> and the nct6775 driver.
>>
>> At least for all the Gigabyte ACPI tables I have looked at all access is done
>> via two-byte "OperationRegion" over the Index/Data addresses, a "Field" with
>> two entries for these and an "IndexField" that is actually used to perform 
>> the
>> accesses.
>> As the IndexField is synchronized via "Lock" it should take a lock on the
>> OperationRegion itself.
>>
>> So I think we should be technically fine with validating these assumption and
>> then also taking locks on the OperationRegion.
>>
>> If it is reasonable to do so is another question.
>>
> You'd still have to validate this for each individual board unless you get
> confirmation from Gigabyte that the mechanism is consistent on their boards.
> Then you'd have to handle other vendors using it87 chips, and those are
> just as close-lipped as Gigabyte. Ultimately it would require acpi match
> tables to match the various boards and access methods. I had experimented
> with this this a long time ago but gave up on it after concluding that it was
> unmaintainable.
> 
>>> Second, access through ACPI is only one of the issues. Turns out there are 
>>> two
>>> ITE chips on many of the Gigabyte boards nowadays, and the two chips talk 
>>> to each
>>> other using I2C. My out-of-tree driver tried to remedy that by blocking 
>>> those
>>> accesses while the driver used the chip, but, again, without Gigabyte / ITE
>>> support this was never a perfect solution, and there was always the risk 
>>> that
>>> the board ended up hanging because that access was blocked for too long.
>>> Recent ITE chips solve that problem by providing memory mapped access to the
>>> chip registers, but that is only useful if one has a datasheet.
>>
>> Are both of these chips available at the two well-known registers 0x2e and
>> 0x4e?
>>
> 
> The ones I know of are, yes.
> 
> Oh, that reminds me, there is another bug. Here are my comments about that:
> 
> /*
>  * On various Gigabyte AM4 boards (AB350, AX370), the second Super-IO chip
>  * (IT8792E) needs to be in configuration mode before accessing the first
>  * due to a bug in IT8792E 

Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-10 Thread Guenter Roeck
On 4/8/21 11:02 PM, Thomas Weißschuh wrote:
> On Do, 2021-04-08T08:00-0700, Guenter Roeck wrote:
>> On 4/8/21 2:36 AM, Hans de Goede wrote:
>>> On 4/7/21 9:43 PM, Thomas Weißschuh wrote:
 On Mi, 2021-04-07T17:54+0200, Hans de Goede wrote:
>>> Jean, Guenter,
>>>
>>> Thomas has been working on a WMI driver to expose various motherboard
>>> temperatures on a gigabyte board where the IO-addresses for the it87 chip
>>> are reserved by ACPI. We are discussing how best to deal with this, there
>>> are some ACPI methods to directly access the super-IO registers (with 
>>> locking
>>> to protect against other ACPI accesses). This reminded me of an idea I had
>>> a while ago to solve a similar issue with an other superIO chip, abstract
>>> the superIO register access-es using some reg_ops struct and allow an 
>>> ACPI/WMI
>>> driver to provide alternative reg_ops:
>>> https://bugzilla.kernel.org/show_bug.cgi?id=204807#c47
>>>
>>> Do you think this is a good idea (or a bad one)? And would something like 
>>> that
>>> be acceptable to you ?
>>>
>>
>> The upstream it87 driver is severely out of date. I had an out-of-tree driver
>> with various improvements which I didn't upstream, first because no one was 
>> willing
>> to review changes and then because it had deviated too much. I pulled it from
>> public view because I got pounded for not upstreaming it, because people 
>> started
>> demanding support (not asking, demanding) for it, and because Gigabyte 
>> stopped
>> providing datasheets for the more recent ITE chips and it became effectively
>> unmaintainable.
>>
>> Some ITE chips have issues which can cause system hangs if accessed directly.
>> I put some work to remedy that into the non-upstream driver, but that was all
>> just guesswork. Gigabyte knows about the problem (or so I was told from 
>> someone
>> who has an NDA with them), but I didn't get them or ITE to even acknowledge 
>> it
>> to me. I even had a support case open with Gigabyte for a while, but all I 
>> could
>> get out of them is that they don't support Linux and what I would have to 
>> reproduce
>> the problem with Windows for them to provide assistance (even though, again,
>> they knew about it).
>>
>> As for using ACPI locks or WMI to ensure that ACPI leaves the chip alone 
>> while
>> the driver accesses chips directly: That is an option, but it has (at least)
>> two problems.
>>
>> First, ACPI access methods are not well documented or standardized. I had 
>> tried
>> to find useful means to do that some time ago, but I gave up because each 
>> board
>> (even from the same vendor) handles locking and accesses differently. We 
>> would
>> end up with lots of board specific code. Coincidentally, that was for ASUS 
>> boards
>> and the nct6775 driver.
> 
> At least for all the Gigabyte ACPI tables I have looked at all access is done
> via two-byte "OperationRegion" over the Index/Data addresses, a "Field" with
> two entries for these and an "IndexField" that is actually used to perform the
> accesses.
> As the IndexField is synchronized via "Lock" it should take a lock on the
> OperationRegion itself.
> 
> So I think we should be technically fine with validating these assumption and
> then also taking locks on the OperationRegion.
> 
> If it is reasonable to do so is another question.
> 
You'd still have to validate this for each individual board unless you get
confirmation from Gigabyte that the mechanism is consistent on their boards.
Then you'd have to handle other vendors using it87 chips, and those are
just as close-lipped as Gigabyte. Ultimately it would require acpi match
tables to match the various boards and access methods. I had experimented
with this this a long time ago but gave up on it after concluding that it was
unmaintainable.

>> Second, access through ACPI is only one of the issues. Turns out there are 
>> two
>> ITE chips on many of the Gigabyte boards nowadays, and the two chips talk to 
>> each
>> other using I2C. My out-of-tree driver tried to remedy that by blocking those
>> accesses while the driver used the chip, but, again, without Gigabyte / ITE
>> support this was never a perfect solution, and there was always the risk that
>> the board ended up hanging because that access was blocked for too long.
>> Recent ITE chips solve that problem by providing memory mapped access to the
>> chip registers, but that is only useful if one has a datasheet.
> 
> Are both of these chips available at the two well-known registers 0x2e and
> 0x4e?
> 

The ones I know of are, yes.

Oh, that reminds me, there is another bug. Here are my comments about that:

/*
 * On various Gigabyte AM4 boards (AB350, AX370), the second Super-IO chip
 * (IT8792E) needs to be in configuration mode before accessing the first
 * due to a bug in IT8792E which otherwise results in LPC bus access errors.
 * This needs to be done before accessing the first Super-IO chip since
 * the second chip may have been accessed prior to loading this driver.
 *
 * 

Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-10 Thread Guenter Roeck
On 4/8/21 9:07 AM, Hans de Goede wrote:
> Hi Guenter,
> 
> On 4/8/21 5:08 PM, Guenter Roeck wrote:
>> On Mon, Apr 05, 2021 at 10:48:10PM +0200, Thomas Weißschuh wrote:
>>> Changes since v1:
>>> * Incorporate feedback from Barnabás Pőcze
>>>   * Use a WMI driver instead of a platform driver
>>>   * Let the kernel manage the driver lifecycle
>>>   * Fix errno/ACPI error confusion
>>>   * Fix resource cleanup
>>>   * Document reason for integer casting
>>>
>>> Thank you Barnabás for your review, it is much appreciated.
>>>
>>> -- >8 --
>>>
>>> Tested with a X570 I Aorus Pro Wifi.
>>> The mainboard contains an ITE IT8688E chip for management.
>>> This chips is also handled by drivers/hwmon/i87.c but as it is also used
>>> by the firmware itself it needs an ACPI driver.
>>>
>>> Unfortunately not all sensor registers are handled by the firmware and even
>>> less are exposed via WMI.
>>>
>>> Signed-off-by: Thomas Weißschuh 
>>> ---
>>>  drivers/platform/x86/Kconfig|  11 +++
>>>  drivers/platform/x86/Makefile   |   1 +
>>>  drivers/platform/x86/gigabyte-wmi.c | 138 
>>
>> Originally drivers/platform was supposed to be used for platform specific
>> code. Not that I have control over it, but I really dislike that more and
>> more hwmon drivers end up there.
>>
>> At least hwmon is in good company - I see drivers for various other 
>> subsystems
>> there as well. I just wonder if that is such a good idea. That entire 
>> directory
>> is bypassing subsystem maintainer reviews.
> 
> In case you are not aware I've recent(ish) taken over the drivers/platform/x86
> maintainership from Andy Shevchenko.
> 
> Yes it is a bit of an odd grab-bag it mostly deals with vendor specific
> ACPI / WMI interfaces which often more or less require using a single
> driver while offering multiple functionalities. These firmware interfaces
> do not really lend themselves to demultiplexing through something like
> MFD. These are mostly found on laptops where they deal with some or all of:
> 
> - Hotkeys for brightness adjust / wlan-on/off toggle, touchpad on/off toggle, 
> etc.
>   (input subsystem stuff)
> - Mic. / Speaker mute LEDS (and other special LEDs) found on some laptops
>   (LED subsystem stuff)
> - Enabling/disabling radios
>   (rfkill stuff)
> - Controlling the DPTF performance profile
>   (ACPI stuff)
> - Various sensors, some hwmon, some IIO
> - Backlight control (drm/kms subsys)
> - Enabling/disabling of LCD-builtin privacy filters (requires KMS/DRM subsys 
> integration, pending)
> - Fan control (hwmon subsys)
> 
> And often all of this in a single driver. This is all "stuff" for which
> there are no standard APIs shared between vendors, so it is a free for
> all and often it is all stuffed behind a single WMI or ACPI object,
> because that is how the vendor's drivers under Windows work.
> 
> It certainly is not my intention to bypass review by other subsystem
> maintainers and when there are significant questions I do try to always
> get other subsys maintainers involved. See e.g. this thread, but also the
> "[PATCH 1/3] thinkpad_acpi: add support for force_discharge" thread
> where I asked for input from sre for the power-supply aspects of that.
> 
> The WMI code was reworked a while back to make WMI be a bus and have
> individual WMI objects be devices on that bus. version 2 of this
> driver has been reworked to use this. Since this new driver is just a hwmon
> driver and as this is for a desktop I expect it will stay that way,
> I'm fine with moving this one over to drivers/hwmon if that has your
> preference.
> 
I thought about it, but I don't think it makes much sense since all other
WMI drivers are in drivers/platform.

> As for other cases then this driver, if you want to make sure you are at
> least Cc-ed on all hwmon related changes I'm fine with adding you as a
> reviewer to the pdx86 MAINTAINERS entry.
> 
I think I have a better idea: I'll add a regex pattern into the MAINTAINERS
entry for hardware monitoring drivers. This way we should get copied whenever
anyone adds a hardware monitoring driver into the tree.

Thanks,
Guenter


Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-09 Thread Thomas Weißschuh
On Do, 2021-04-08T08:00-0700, Guenter Roeck wrote:
> On 4/8/21 2:36 AM, Hans de Goede wrote:
> > On 4/7/21 9:43 PM, Thomas Weißschuh wrote:
> >> On Mi, 2021-04-07T17:54+0200, Hans de Goede wrote:
> > Jean, Guenter,
> > 
> > Thomas has been working on a WMI driver to expose various motherboard
> > temperatures on a gigabyte board where the IO-addresses for the it87 chip
> > are reserved by ACPI. We are discussing how best to deal with this, there
> > are some ACPI methods to directly access the super-IO registers (with 
> > locking
> > to protect against other ACPI accesses). This reminded me of an idea I had
> > a while ago to solve a similar issue with an other superIO chip, abstract
> > the superIO register access-es using some reg_ops struct and allow an 
> > ACPI/WMI
> > driver to provide alternative reg_ops:
> > https://bugzilla.kernel.org/show_bug.cgi?id=204807#c47
> > 
> > Do you think this is a good idea (or a bad one)? And would something like 
> > that
> > be acceptable to you ?
> > 
> 
> The upstream it87 driver is severely out of date. I had an out-of-tree driver
> with various improvements which I didn't upstream, first because no one was 
> willing
> to review changes and then because it had deviated too much. I pulled it from
> public view because I got pounded for not upstreaming it, because people 
> started
> demanding support (not asking, demanding) for it, and because Gigabyte stopped
> providing datasheets for the more recent ITE chips and it became effectively
> unmaintainable.
> 
> Some ITE chips have issues which can cause system hangs if accessed directly.
> I put some work to remedy that into the non-upstream driver, but that was all
> just guesswork. Gigabyte knows about the problem (or so I was told from 
> someone
> who has an NDA with them), but I didn't get them or ITE to even acknowledge it
> to me. I even had a support case open with Gigabyte for a while, but all I 
> could
> get out of them is that they don't support Linux and what I would have to 
> reproduce
> the problem with Windows for them to provide assistance (even though, again,
> they knew about it).
> 
> As for using ACPI locks or WMI to ensure that ACPI leaves the chip alone while
> the driver accesses chips directly: That is an option, but it has (at least)
> two problems.
> 
> First, ACPI access methods are not well documented or standardized. I had 
> tried
> to find useful means to do that some time ago, but I gave up because each 
> board
> (even from the same vendor) handles locking and accesses differently. We would
> end up with lots of board specific code. Coincidentally, that was for ASUS 
> boards
> and the nct6775 driver.

At least for all the Gigabyte ACPI tables I have looked at all access is done
via two-byte "OperationRegion" over the Index/Data addresses, a "Field" with
two entries for these and an "IndexField" that is actually used to perform the
accesses.
As the IndexField is synchronized via "Lock" it should take a lock on the
OperationRegion itself.

So I think we should be technically fine with validating these assumption and
then also taking locks on the OperationRegion.

If it is reasonable to do so is another question.

> Second, access through ACPI is only one of the issues. Turns out there are two
> ITE chips on many of the Gigabyte boards nowadays, and the two chips talk to 
> each
> other using I2C. My out-of-tree driver tried to remedy that by blocking those
> accesses while the driver used the chip, but, again, without Gigabyte / ITE
> support this was never a perfect solution, and there was always the risk that
> the board ended up hanging because that access was blocked for too long.
> Recent ITE chips solve that problem by providing memory mapped access to the
> chip registers, but that is only useful if one has a datasheet.

Are both of these chips available at the two well-known registers 0x2e and
0x4e?

Would this too-long blocking also occur when only accessing single registers
for read-only access?
Any write access would probably have to be blocked anyways.

> Overall, I don't think it makes much sense trying to make significant changes
> to the it87 driver without pulling in all the changes I had made, and without
> finding a better fix for the cross-chip access problems. I for sure won't have
> time for that (and getting hwmon patches reviewed is still very much an 
> issue).
> 
> Having said that, I am of course open to adding WMI/ACPI drivers for the 
> various
> boards. Good luck getting support from Gigabyte, though. Or from ASUS, for 
> that
> matter.

Thomas


Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-08 Thread Hans de Goede
Hi Guenter,

On 4/8/21 5:08 PM, Guenter Roeck wrote:
> On Mon, Apr 05, 2021 at 10:48:10PM +0200, Thomas Weißschuh wrote:
>> Changes since v1:
>> * Incorporate feedback from Barnabás Pőcze
>>   * Use a WMI driver instead of a platform driver
>>   * Let the kernel manage the driver lifecycle
>>   * Fix errno/ACPI error confusion
>>   * Fix resource cleanup
>>   * Document reason for integer casting
>>
>> Thank you Barnabás for your review, it is much appreciated.
>>
>> -- >8 --
>>
>> Tested with a X570 I Aorus Pro Wifi.
>> The mainboard contains an ITE IT8688E chip for management.
>> This chips is also handled by drivers/hwmon/i87.c but as it is also used
>> by the firmware itself it needs an ACPI driver.
>>
>> Unfortunately not all sensor registers are handled by the firmware and even
>> less are exposed via WMI.
>>
>> Signed-off-by: Thomas Weißschuh 
>> ---
>>  drivers/platform/x86/Kconfig|  11 +++
>>  drivers/platform/x86/Makefile   |   1 +
>>  drivers/platform/x86/gigabyte-wmi.c | 138 
> 
> Originally drivers/platform was supposed to be used for platform specific
> code. Not that I have control over it, but I really dislike that more and
> more hwmon drivers end up there.
> 
> At least hwmon is in good company - I see drivers for various other subsystems
> there as well. I just wonder if that is such a good idea. That entire 
> directory
> is bypassing subsystem maintainer reviews.

In case you are not aware I've recent(ish) taken over the drivers/platform/x86
maintainership from Andy Shevchenko.

Yes it is a bit of an odd grab-bag it mostly deals with vendor specific
ACPI / WMI interfaces which often more or less require using a single
driver while offering multiple functionalities. These firmware interfaces
do not really lend themselves to demultiplexing through something like
MFD. These are mostly found on laptops where they deal with some or all of:

- Hotkeys for brightness adjust / wlan-on/off toggle, touchpad on/off toggle, 
etc.
  (input subsystem stuff)
- Mic. / Speaker mute LEDS (and other special LEDs) found on some laptops
  (LED subsystem stuff)
- Enabling/disabling radios
  (rfkill stuff)
- Controlling the DPTF performance profile
  (ACPI stuff)
- Various sensors, some hwmon, some IIO
- Backlight control (drm/kms subsys)
- Enabling/disabling of LCD-builtin privacy filters (requires KMS/DRM subsys 
integration, pending)
- Fan control (hwmon subsys)

And often all of this in a single driver. This is all "stuff" for which
there are no standard APIs shared between vendors, so it is a free for
all and often it is all stuffed behind a single WMI or ACPI object,
because that is how the vendor's drivers under Windows work.

It certainly is not my intention to bypass review by other subsystem
maintainers and when there are significant questions I do try to always
get other subsys maintainers involved. See e.g. this thread, but also the
"[PATCH 1/3] thinkpad_acpi: add support for force_discharge" thread
where I asked for input from sre for the power-supply aspects of that.

The WMI code was reworked a while back to make WMI be a bus and have
individual WMI objects be devices on that bus. version 2 of this
driver has been reworked to use this. Since this new driver is just a hwmon
driver and as this is for a desktop I expect it will stay that way,
I'm fine with moving this one over to drivers/hwmon if that has your
preference.

As for other cases then this driver, if you want to make sure you are at
least Cc-ed on all hwmon related changes I'm fine with adding you as a
reviewer to the pdx86 MAINTAINERS entry.

Regards,

Hans




> 
> Guenter
> 
>>  3 files changed, 150 insertions(+)
>>  create mode 100644 drivers/platform/x86/gigabyte-wmi.c
>>
>> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
>> index ad4e630e73e2..96622a2106f7 100644
>> --- a/drivers/platform/x86/Kconfig
>> +++ b/drivers/platform/x86/Kconfig
>> @@ -123,6 +123,17 @@ config XIAOMI_WMI
>>To compile this driver as a module, choose M here: the module will
>>be called xiaomi-wmi.
>>  
>> +config GIGABYTE_WMI
>> +tristate "Gigabyte WMI temperature driver"
>> +depends on ACPI_WMI
>> +depends on HWMON
>> +help
>> +  Say Y here if you want to support WMI-based temperature reporting on
>> +  Gigabyte mainboards.
>> +
>> +  To compile this driver as a module, choose M here: the module will
>> +  be called gigabyte-wmi.
>> +
>>  config ACERHDF
>>  tristate "Acer Aspire One temperature and fan driver"
>>  depends on ACPI && THERMAL
>> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
>> index 60d554073749..1621ebfd04fd 100644
>> --- a/drivers/platform/x86/Makefile
>> +++ b/drivers/platform/x86/Makefile
>> @@ -15,6 +15,7 @@ obj-$(CONFIG_INTEL_WMI_THUNDERBOLT)+= 
>> intel-wmi-thunderbolt.o
>>  obj-$(CONFIG_MXM_WMI)   += mxm-wmi.o
>>  obj-$(CONFIG_PEAQ_WMI)  

Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-08 Thread Guenter Roeck
On Mon, Apr 05, 2021 at 10:48:10PM +0200, Thomas Weißschuh wrote:
> Changes since v1:
> * Incorporate feedback from Barnabás Pőcze
>   * Use a WMI driver instead of a platform driver
>   * Let the kernel manage the driver lifecycle
>   * Fix errno/ACPI error confusion
>   * Fix resource cleanup
>   * Document reason for integer casting
> 
> Thank you Barnabás for your review, it is much appreciated.
> 
> -- >8 --
> 
> Tested with a X570 I Aorus Pro Wifi.
> The mainboard contains an ITE IT8688E chip for management.
> This chips is also handled by drivers/hwmon/i87.c but as it is also used
> by the firmware itself it needs an ACPI driver.
> 
> Unfortunately not all sensor registers are handled by the firmware and even
> less are exposed via WMI.
> 
> Signed-off-by: Thomas Weißschuh 
> ---
>  drivers/platform/x86/Kconfig|  11 +++
>  drivers/platform/x86/Makefile   |   1 +
>  drivers/platform/x86/gigabyte-wmi.c | 138 

Originally drivers/platform was supposed to be used for platform specific
code. Not that I have control over it, but I really dislike that more and
more hwmon drivers end up there.

At least hwmon is in good company - I see drivers for various other subsystems
there as well. I just wonder if that is such a good idea. That entire directory
is bypassing subsystem maintainer reviews.

Guenter

>  3 files changed, 150 insertions(+)
>  create mode 100644 drivers/platform/x86/gigabyte-wmi.c
> 
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index ad4e630e73e2..96622a2106f7 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -123,6 +123,17 @@ config XIAOMI_WMI
> To compile this driver as a module, choose M here: the module will
> be called xiaomi-wmi.
>  
> +config GIGABYTE_WMI
> + tristate "Gigabyte WMI temperature driver"
> + depends on ACPI_WMI
> + depends on HWMON
> + help
> +   Say Y here if you want to support WMI-based temperature reporting on
> +   Gigabyte mainboards.
> +
> +   To compile this driver as a module, choose M here: the module will
> +   be called gigabyte-wmi.
> +
>  config ACERHDF
>   tristate "Acer Aspire One temperature and fan driver"
>   depends on ACPI && THERMAL
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index 60d554073749..1621ebfd04fd 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_INTEL_WMI_THUNDERBOLT) += 
> intel-wmi-thunderbolt.o
>  obj-$(CONFIG_MXM_WMI)+= mxm-wmi.o
>  obj-$(CONFIG_PEAQ_WMI)   += peaq-wmi.o
>  obj-$(CONFIG_XIAOMI_WMI) += xiaomi-wmi.o
> +obj-$(CONFIG_GIGABYTE_WMI)   += gigabyte-wmi.o
>  
>  # Acer
>  obj-$(CONFIG_ACERHDF)+= acerhdf.o
> diff --git a/drivers/platform/x86/gigabyte-wmi.c 
> b/drivers/platform/x86/gigabyte-wmi.c
> new file mode 100644
> index ..8618363e3ccf
> --- /dev/null
> +++ b/drivers/platform/x86/gigabyte-wmi.c
> @@ -0,0 +1,138 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + *  Copyright (C) 2021 Thomas Weißschuh 
> + */
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include 
> +#include 
> +#include 
> +#include 
> +
> +#define GIGABYTE_WMI_GUID "DEADBEEF-2001--00A0-C9062910"
> +
> +enum gigabyte_wmi_commandtype {
> + GIGABYTE_WMI_BUILD_DATE_QUERY   =   0x1,
> + GIGABYTE_WMI_MAINBOARD_TYPE_QUERY   =   0x2,
> + GIGABYTE_WMI_FIRMWARE_VERSION_QUERY =   0x4,
> + GIGABYTE_WMI_MAINBOARD_NAME_QUERY   =   0x5,
> + GIGABYTE_WMI_TEMPERATURE_QUERY  = 0x125,
> +};
> +
> +struct gigabyte_wmi_args {
> + u32 arg1;
> +};
> +
> +static int gigabyte_wmi_perform_query(enum gigabyte_wmi_commandtype command,
> + struct gigabyte_wmi_args *args, struct acpi_buffer *out)
> +{
> + const struct acpi_buffer in = {
> + .length = sizeof(*args),
> + .pointer = args,
> + };
> +
> + acpi_status ret = wmi_evaluate_method(GIGABYTE_WMI_GUID, 0x0, command, 
> , out);
> + if (ret == AE_OK) {
> + return 0;
> + } else {
> + return -EIO;
> + };
> +}
> +
> +static int gigabyte_wmi_query_integer(enum gigabyte_wmi_commandtype command,
> + struct gigabyte_wmi_args *args, u64 *res)
> +{
> + union acpi_object *obj;
> + struct acpi_buffer result = { ACPI_ALLOCATE_BUFFER, NULL };
> + int ret;
> +
> + ret = gigabyte_wmi_perform_query(command, args, );
> + if (ret) {
> + goto out;
> + }
> + obj = result.pointer;
> + if (obj && obj->type == ACPI_TYPE_INTEGER) {
> + *res = obj->integer.value;
> + ret = 0;
> + } else {
> + ret = -EIO;
> + }
> +out:
> + kfree(result.pointer);
> + return ret;
> +}
> +
> +static int gigabyte_wmi_temperature(u8 sensor, long *res)
> +{
> + struct 

Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-08 Thread Guenter Roeck
On 4/8/21 2:36 AM, Hans de Goede wrote:
> Hi,
> 
> On 4/7/21 9:43 PM, Thomas Weißschuh wrote:
>> Hi Hans,
>>
>> On Mi, 2021-04-07T17:54+0200, Hans de Goede wrote:
>>> Thank you for your new driver and thank you for the quick respin
>>> addressing Barnabás' request to make it a WMI driver.
>>>
>>> The code looks good, so merging this should be a no-brainer,
>>> yet I'm not sure if I should merge this driver as-is, let me
>>> explain.
>>
>> thanks for the encouraging words.
>>
>>> The problem is that I assume that this is based on reverse-engineering?
>>
>> Yes, it is completely reverse-engineered.
>> Essentially I stumbled upon Matthews comment at
>> https://bugzilla.kernel.org/show_bug.cgi?id=204807#c37 and went from there.
>>
>>> We have some mixes experiences with reverse-engineered WMI drivers,
>>> sometimes a feature is not supported yet the wmi_evaluate_method()
>>> call happily succeeds. One example of this causing trouble is:
>>>
>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1797d588af15174d4a4e7159dac8c800538e4f8c
>>
>> There actually are reports of recent, similar mainboards with recent 
>> firmware and
>> similar sensor chips that do not support the temperature query.
>> (https://github.com/t-8ch/linux-gigabyte-wmi-driver/issues/3 and
>> https://github.com/t-8ch/linux-gigabyte-wmi-driver/issues/2)
>>
>> Unfortunately for unknown WMI queries the firmware does not return any value.
>> This ends up as an ACPI integer with value 0 on the driver side.
>> (Which I could not yet find documentation for if that is expected)
>> In the current version of the driver EIO is returned for 0 values which
>> get translated to N/A by lm-sensors.
>>
>>> At a minimum I think your driver should check in its
>>> probe function that
>>>
>>> gigabyte_wmi_query_integer(GIGABYTE_WMI_TEMPERATURE_QUERY, ...)
>>>
>>> actually succeeds on the machine the driver is running on chances
>>> are that Gigabyte has been using the DEADBEEF-2001--00A0-C9062910
>>> GUID for ages, where as the 0x125 value for GIGABYTE_WMI_TEMPERATURE_QUERY
>>> suggests that this is a pretty new API.
>>
>> Would it be enough to probe all six sensors and check if all return 0?
> 
> I think that failing the probe with -ENODEV, with a dev_info() explaining why 
> when
> all six sensors return 0 would be good yes, that should also fix those 2
> issues on https://github.com/t-8ch/linux-gigabyte-wmi-driver/.
> 
>>> It would be good if you can see if you can find some DSDT-s for older
>>> gigabyte motherboards attached to various distro's bug-tracking systems
>>> or forum posts and see how those respond to an unknown 
>>> gigabyte_wmi_commandtype.
>>
>> Will do.
> 
> Since you alreayd have bugreports of boards where this does not work,
> please don't spend too much time on this. I guess those older DSDT-s will
> also just return an integer with value 0.
> 
>>> Another open question to make sure this driver is suitable
>>> as a generic driver (and does not misbehave) is how to figure out
>>> how many temperature sensors there actually are.
>>
>> So far I could not find out how to query this from the firmware.
>> The IT8688 chip can report the state of each sensor but that is not exposed 
>> by
>> the firmware.
>> But even the state information from the IT8688 is not accurate as is.
>> One of the sensors that is reported as being active (directly via it87) on my
>> machine always reports -55°C (yes, negative).
> 
> Ok.
> 
>>> Perhaps the WMI interface returns an error when you query an out-of-range
>>> temperature channel?
>>
>> Also "0" as mentioned above.
> 
> Hmm, so maybe this can be used to limit the amount of reported temperature
> sensors, IOW if sensors 5 and 6 report 0, only register 4 sensors ?
> 
>>
>>> One option here might be to add a DMI matching table and only load on
>>> systems on that table for now. That table could then perhaps also provide
>>> labels for each of the temperature channels, which is something which
>>> would be nice to have regardless of my worries about how well this driver
>>> will work on motherboards on which it has not been tested.
>>
>> I am collecting reports for working motherboards at
>> https://github.com/t-8ch/linux-gigabyte-wmi-driver/issues/1 .
> 
> Good, you should probably ask reporters there to provide the output of:
> 
> grep . /sys/class/dmi/id/* 2> /dev/null
> 
> Ran as a normal user (so that the serial-numbers will be skipped) so that
> you will have DMI strings to match on if you decide to go that route.
> 
>>
>>> You could combine this DMI matching table with a "force" module option to
>>> continue with probing on boards which are not on the table to allow users
>>> to test and report their results to you.
>>>
>>> And hopefully after a while, when we're confident that the code works
>>> well on most gigabyte boards we can drop the DMI table, or at least
>>> only use it for the channel labels.
>>
>> That sounds good.
>>
>>> Please don't take this the wrong way; I 

Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-08 Thread Thomas Weißschuh
Hi Hans,

On Do, 2021-04-08T11:36+0200, Hans de Goede wrote:
> On 4/7/21 9:43 PM, Thomas Weißschuh wrote:
> > Hi Hans,
> > 
> > On Mi, 2021-04-07T17:54+0200, Hans de Goede wrote:
> >> Thank you for your new driver and thank you for the quick respin
> >> addressing Barnabás' request to make it a WMI driver.
> >>
> >> The code looks good, so merging this should be a no-brainer,
> >> yet I'm not sure if I should merge this driver as-is, let me
> >> explain.
> > 
> > thanks for the encouraging words.
> > 
> >> The problem is that I assume that this is based on reverse-engineering?
> > 
> > Yes, it is completely reverse-engineered.
> > Essentially I stumbled upon Matthews comment at
> > https://bugzilla.kernel.org/show_bug.cgi?id=204807#c37 and went from there.
> > 
> >> We have some mixes experiences with reverse-engineered WMI drivers,
> >> sometimes a feature is not supported yet the wmi_evaluate_method()
> >> call happily succeeds. One example of this causing trouble is:
> >>
> >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1797d588af15174d4a4e7159dac8c800538e4f8c
> > 
> > There actually are reports of recent, similar mainboards with recent 
> > firmware and
> > similar sensor chips that do not support the temperature query.
> > (https://github.com/t-8ch/linux-gigabyte-wmi-driver/issues/3 and
> > https://github.com/t-8ch/linux-gigabyte-wmi-driver/issues/2)
> > 
> > Unfortunately for unknown WMI queries the firmware does not return any 
> > value.
> > This ends up as an ACPI integer with value 0 on the driver side.
> > (Which I could not yet find documentation for if that is expected)
> > In the current version of the driver EIO is returned for 0 values which
> > get translated to N/A by lm-sensors.
> > 
> >> At a minimum I think your driver should check in its
> >> probe function that
> >>
> >> gigabyte_wmi_query_integer(GIGABYTE_WMI_TEMPERATURE_QUERY, ...)
> >>
> >> actually succeeds on the machine the driver is running on chances
> >> are that Gigabyte has been using the DEADBEEF-2001--00A0-C9062910
> >> GUID for ages, where as the 0x125 value for GIGABYTE_WMI_TEMPERATURE_QUERY
> >> suggests that this is a pretty new API.
> > 
> > Would it be enough to probe all six sensors and check if all return 0?
> 
> I think that failing the probe with -ENODEV, with a dev_info() explaining why 
> when
> all six sensors return 0 would be good yes, that should also fix those 2
> issues on https://github.com/t-8ch/linux-gigabyte-wmi-driver/.

I added such a validation step.

> >> It would be good if you can see if you can find some DSDT-s for older
> >> gigabyte motherboards attached to various distro's bug-tracking systems
> >> or forum posts and see how those respond to an unknown 
> >> gigabyte_wmi_commandtype.
> > 
> > Will do.
> 
> Since you alreayd have bugreports of boards where this does not work,
> please don't spend too much time on this. I guess those older DSDT-s will
> also just return an integer with value 0.

Ok.

> >> Another open question to make sure this driver is suitable
> >> as a generic driver (and does not misbehave) is how to figure out
> >> how many temperature sensors there actually are.
> > 
> > So far I could not find out how to query this from the firmware.
> > The IT8688 chip can report the state of each sensor but that is not exposed 
> > by
> > the firmware.
> > But even the state information from the IT8688 is not accurate as is.
> > One of the sensors that is reported as being active (directly via it87) on 
> > my
> > machine always reports -55°C (yes, negative).
> 
> Ok.
> 
> >> Perhaps the WMI interface returns an error when you query an out-of-range
> >> temperature channel?
> > 
> > Also "0" as mentioned above.
> 
> Hmm, so maybe this can be used to limit the amount of reported temperature
> sensors, IOW if sensors 5 and 6 report 0, only register 4 sensors ?

So far the 0-returning sensors have not been at the end of the list but in the
middle. Is it worth building logic to properly probe a bitmask of useful
sensors?

> >> One option here might be to add a DMI matching table and only load on
> >> systems on that table for now. That table could then perhaps also provide
> >> labels for each of the temperature channels, which is something which
> >> would be nice to have regardless of my worries about how well this driver
> >> will work on motherboards on which it has not been tested.
> > 
> > I am collecting reports for working motherboards at
> > https://github.com/t-8ch/linux-gigabyte-wmi-driver/issues/1 .
> 
> Good, you should probably ask reporters there to provide the output of:
> 
> grep . /sys/class/dmi/id/* 2> /dev/null

I added a DMI-based whitelist and asked users to submit their DMI information.

> Ran as a normal user (so that the serial-numbers will be skipped) so that
> you will have DMI strings to match on if you decide to go that route.

The serials seem not to be too critical on these boards:


Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-08 Thread Thomas Weißschuh
Hi,

On Mi, 2021-04-07T18:27+, Barnabás Pőcze wrote:
> 2021. április 5., hétfő 22:48 keltezéssel, Thomas Weißschuh írta:
> > Tested with a X570 I Aorus Pro Wifi.
> > The mainboard contains an ITE IT8688E chip for management.
> > This chips is also handled by drivers/hwmon/i87.c but as it is also used
> > by the firmware itself it needs an ACPI driver.
> 
> I gather this means you're getting the
> 
>   ACPI Warning: SystemIO range ... conflicts with ...
>   ACPI: If an ACPI driver is available for this device, you should use it 
> instead of the native driver
> 
> warning?

Exactly.

> > +struct gigabyte_wmi_args {
> > +   u32 arg1;
> > +};
> > +
> > +static int gigabyte_wmi_perform_query(enum gigabyte_wmi_commandtype 
> > command,
> > +   struct gigabyte_wmi_args *args, struct acpi_buffer *out)
> > +{
> > +   const struct acpi_buffer in = {
> > +   .length = sizeof(*args),
> > +   .pointer = args,
> > +   };
> > +
> > +   acpi_status ret = wmi_evaluate_method(GIGABYTE_WMI_GUID, 0x0, command, 
> > , out);
> 
> Ideally, you'd use the WMI device that was passed to the probe method to do 
> the query
> using `wmidev_evaluate_method()`. You can pass the WMI device pointer
> to `devm_hwmon_device_register_with_info()` in the `drvdata` argument,
> then in the ->read() callback you can retrieve it:
> 
>   static int gigabyte_wmi_hwmon_read(struct device *dev, ...)
>   {
> struct wmi_device *wdev = dev_get_drvdata(dev);
> 
> and then you can pass that to the other functions.

Done.

> > +   if (ret == AE_OK) {
> > +   return 0;
> > +   } else {
> > +   return -EIO;
> > +   };
> 
> The `;` is not needed. And please use `ACPI_FAILURE()` or `ACPI_SUCCESS()`
> to check the returned value. For example:
> 
>   acpi_status ret = ...;
>   if (ACPI_FAILURE(ret))
> return -EIO;
> 
>   return 0;

Done.

> > +}
> > +
> > +static int gigabyte_wmi_query_integer(enum gigabyte_wmi_commandtype 
> > command,
> > +   struct gigabyte_wmi_args *args, u64 *res)
> > +{
> > +   union acpi_object *obj;
> > +   struct acpi_buffer result = { ACPI_ALLOCATE_BUFFER, NULL };
> > +   int ret;
> > +
> > +   ret = gigabyte_wmi_perform_query(command, args, );
> > +   if (ret) {
> > +   goto out;
> 
> I believe if this branch is taken, no buffer is allocated (due to the 
> failure),
> so you can just `return ret;` here and do away with the goto completely - if 
> I'm not mistaken.

Done.

> > +static const struct hwmon_channel_info *gigabyte_wmi_hwmon_info[] = {
> > +   HWMON_CHANNEL_INFO(temp,
> > +   HWMON_T_INPUT,
> > +   HWMON_T_INPUT,
> > +   HWMON_T_INPUT,
> > +   HWMON_T_INPUT,
> > +   HWMON_T_INPUT,
> > +   HWMON_T_INPUT),
> > +   NULL,
> ^
> Minor thing: usually commas after sentinel values are omitted.

Done.

> > +static const struct wmi_device_id gigabyte_wmi_id_table[] = {
> > +   { GIGABYTE_WMI_GUID, NULL },
> > +   { },
>^
> Same here.

Done.

> 
> > +};
> > +
> > +static struct wmi_driver gigabyte_wmi_driver = {
> > +   .driver = {
> > +   .name = "gigabyte-wmi",
> > +   },
> > +   .id_table = gigabyte_wmi_id_table,
> > +   .probe = gigabyte_wmi_probe,
> > +};
> > +module_wmi_driver(gigabyte_wmi_driver);
> > +
> > +MODULE_DEVICE_TABLE(wmi, gigabyte_wmi_id_table);
> > +MODULE_AUTHOR("Thomas Weißschuh ");
> > +MODULE_DESCRIPTION("Gigabyte Temperature WMI Driver");
> 
> It's a very minor thing, but could you please
> synchronize this description with the Kconfig?

Of course.

Thanks again for the review!

Thomas


Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-08 Thread Hans de Goede
Hi,

On 4/7/21 9:43 PM, Thomas Weißschuh wrote:
> Hi Hans,
> 
> On Mi, 2021-04-07T17:54+0200, Hans de Goede wrote:
>> Thank you for your new driver and thank you for the quick respin
>> addressing Barnabás' request to make it a WMI driver.
>>
>> The code looks good, so merging this should be a no-brainer,
>> yet I'm not sure if I should merge this driver as-is, let me
>> explain.
> 
> thanks for the encouraging words.
> 
>> The problem is that I assume that this is based on reverse-engineering?
> 
> Yes, it is completely reverse-engineered.
> Essentially I stumbled upon Matthews comment at
> https://bugzilla.kernel.org/show_bug.cgi?id=204807#c37 and went from there.
> 
>> We have some mixes experiences with reverse-engineered WMI drivers,
>> sometimes a feature is not supported yet the wmi_evaluate_method()
>> call happily succeeds. One example of this causing trouble is:
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1797d588af15174d4a4e7159dac8c800538e4f8c
> 
> There actually are reports of recent, similar mainboards with recent firmware 
> and
> similar sensor chips that do not support the temperature query.
> (https://github.com/t-8ch/linux-gigabyte-wmi-driver/issues/3 and
> https://github.com/t-8ch/linux-gigabyte-wmi-driver/issues/2)
> 
> Unfortunately for unknown WMI queries the firmware does not return any value.
> This ends up as an ACPI integer with value 0 on the driver side.
> (Which I could not yet find documentation for if that is expected)
> In the current version of the driver EIO is returned for 0 values which
> get translated to N/A by lm-sensors.
> 
>> At a minimum I think your driver should check in its
>> probe function that
>>
>> gigabyte_wmi_query_integer(GIGABYTE_WMI_TEMPERATURE_QUERY, ...)
>>
>> actually succeeds on the machine the driver is running on chances
>> are that Gigabyte has been using the DEADBEEF-2001--00A0-C9062910
>> GUID for ages, where as the 0x125 value for GIGABYTE_WMI_TEMPERATURE_QUERY
>> suggests that this is a pretty new API.
> 
> Would it be enough to probe all six sensors and check if all return 0?

I think that failing the probe with -ENODEV, with a dev_info() explaining why 
when
all six sensors return 0 would be good yes, that should also fix those 2
issues on https://github.com/t-8ch/linux-gigabyte-wmi-driver/.

>> It would be good if you can see if you can find some DSDT-s for older
>> gigabyte motherboards attached to various distro's bug-tracking systems
>> or forum posts and see how those respond to an unknown 
>> gigabyte_wmi_commandtype.
> 
> Will do.

Since you alreayd have bugreports of boards where this does not work,
please don't spend too much time on this. I guess those older DSDT-s will
also just return an integer with value 0.

>> Another open question to make sure this driver is suitable
>> as a generic driver (and does not misbehave) is how to figure out
>> how many temperature sensors there actually are.
> 
> So far I could not find out how to query this from the firmware.
> The IT8688 chip can report the state of each sensor but that is not exposed by
> the firmware.
> But even the state information from the IT8688 is not accurate as is.
> One of the sensors that is reported as being active (directly via it87) on my
> machine always reports -55°C (yes, negative).

Ok.

>> Perhaps the WMI interface returns an error when you query an out-of-range
>> temperature channel?
> 
> Also "0" as mentioned above.

Hmm, so maybe this can be used to limit the amount of reported temperature
sensors, IOW if sensors 5 and 6 report 0, only register 4 sensors ?

> 
>> One option here might be to add a DMI matching table and only load on
>> systems on that table for now. That table could then perhaps also provide
>> labels for each of the temperature channels, which is something which
>> would be nice to have regardless of my worries about how well this driver
>> will work on motherboards on which it has not been tested.
> 
> I am collecting reports for working motherboards at
> https://github.com/t-8ch/linux-gigabyte-wmi-driver/issues/1 .

Good, you should probably ask reporters there to provide the output of:

grep . /sys/class/dmi/id/* 2> /dev/null

Ran as a normal user (so that the serial-numbers will be skipped) so that
you will have DMI strings to match on if you decide to go that route.

> 
>> You could combine this DMI matching table with a "force" module option to
>> continue with probing on boards which are not on the table to allow users
>> to test and report their results to you.
>>
>> And hopefully after a while, when we're confident that the code works
>> well on most gigabyte boards we can drop the DMI table, or at least
>> only use it for the channel labels.
> 
> That sounds good.
> 
>> Please don't take this the wrong way; I think it is great that you are
>> working on this. And the quick turnaround of the v2 of this drivers makes
>> me pretty certain that we can figure something out and get this 

Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-07 Thread Thomas Weißschuh
Hi Hans,

On Mi, 2021-04-07T17:54+0200, Hans de Goede wrote:
> Thank you for your new driver and thank you for the quick respin
> addressing Barnabás' request to make it a WMI driver.
> 
> The code looks good, so merging this should be a no-brainer,
> yet I'm not sure if I should merge this driver as-is, let me
> explain.

thanks for the encouraging words.

> The problem is that I assume that this is based on reverse-engineering?

Yes, it is completely reverse-engineered.
Essentially I stumbled upon Matthews comment at
https://bugzilla.kernel.org/show_bug.cgi?id=204807#c37 and went from there.

> We have some mixes experiences with reverse-engineered WMI drivers,
> sometimes a feature is not supported yet the wmi_evaluate_method()
> call happily succeeds. One example of this causing trouble is:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1797d588af15174d4a4e7159dac8c800538e4f8c

There actually are reports of recent, similar mainboards with recent firmware 
and
similar sensor chips that do not support the temperature query.
(https://github.com/t-8ch/linux-gigabyte-wmi-driver/issues/3 and
https://github.com/t-8ch/linux-gigabyte-wmi-driver/issues/2)

Unfortunately for unknown WMI queries the firmware does not return any value.
This ends up as an ACPI integer with value 0 on the driver side.
(Which I could not yet find documentation for if that is expected)
In the current version of the driver EIO is returned for 0 values which
get translated to N/A by lm-sensors.

> At a minimum I think your driver should check in its
> probe function that
> 
> gigabyte_wmi_query_integer(GIGABYTE_WMI_TEMPERATURE_QUERY, ...)
> 
> actually succeeds on the machine the driver is running on chances
> are that Gigabyte has been using the DEADBEEF-2001--00A0-C9062910
> GUID for ages, where as the 0x125 value for GIGABYTE_WMI_TEMPERATURE_QUERY
> suggests that this is a pretty new API.

Would it be enough to probe all six sensors and check if all return 0?

> It would be good if you can see if you can find some DSDT-s for older
> gigabyte motherboards attached to various distro's bug-tracking systems
> or forum posts and see how those respond to an unknown 
> gigabyte_wmi_commandtype.

Will do.

> Another open question to make sure this driver is suitable
> as a generic driver (and does not misbehave) is how to figure out
> how many temperature sensors there actually are.

So far I could not find out how to query this from the firmware.
The IT8688 chip can report the state of each sensor but that is not exposed by
the firmware.
But even the state information from the IT8688 is not accurate as is.
One of the sensors that is reported as being active (directly via it87) on my
machine always reports -55°C (yes, negative).

> Perhaps the WMI interface returns an error when you query an out-of-range
> temperature channel?

Also "0" as mentioned above.

> One option here might be to add a DMI matching table and only load on
> systems on that table for now. That table could then perhaps also provide
> labels for each of the temperature channels, which is something which
> would be nice to have regardless of my worries about how well this driver
> will work on motherboards on which it has not been tested.

I am collecting reports for working motherboards at
https://github.com/t-8ch/linux-gigabyte-wmi-driver/issues/1 .

> You could combine this DMI matching table with a "force" module option to
> continue with probing on boards which are not on the table to allow users
> to test and report their results to you.
>
> And hopefully after a while, when we're confident that the code works
> well on most gigabyte boards we can drop the DMI table, or at least
> only use it for the channel labels.

That sounds good.

> Please don't take this the wrong way; I think it is great that you are
> working on this. And the quick turnaround of the v2 of this drivers makes
> me pretty certain that we can figure something out and get this merged.

Thank you for the feedback!

> Have you tried contacting Gigabyte about this? I don't think the WMI
> interface is something which they need to keep secret for competitive
> reasons, so maybe they can help? Note if they want you to sign a NDA
> of sorts to view docs, then make sure that it contains some language
> about them allowing you to release an opensource driver for their
> hardware based on the "protected" information.

I have not contacted them yet, will do.

As mentioned in the initial patch submission there would be different ways to
access this information firmware:

* Directly call the underlying ACPI methods (these are present in all so far
  observed firmwares, even if not exposed via WMI).
* Directly access the ACPI IndexField representing the it87 chip.
* Directly access the it87 registers while holding the relevant locks via ACPI.

I assume all of those mechanisms have no place in a proper kernel driver but
would like to get your opinion on it.

Thomas


Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-07 Thread Barnabás Pőcze
Hi


2021. április 5., hétfő 22:48 keltezéssel, Thomas Weißschuh írta:

> Changes since v1:
> * Incorporate feedback from Barnabás Pőcze
>   * Use a WMI driver instead of a platform driver
>   * Let the kernel manage the driver lifecycle
>   * Fix errno/ACPI error confusion
>   * Fix resource cleanup
>   * Document reason for integer casting
>
> Thank you Barnabás for your review, it is much appreciated.
>
> -- >8 --
>
> Tested with a X570 I Aorus Pro Wifi.
> The mainboard contains an ITE IT8688E chip for management.
> This chips is also handled by drivers/hwmon/i87.c but as it is also used
> by the firmware itself it needs an ACPI driver.

I gather this means you're getting the

  ACPI Warning: SystemIO range ... conflicts with ...
  ACPI: If an ACPI driver is available for this device, you should use it 
instead of the native driver

warning?


>
> Unfortunately not all sensor registers are handled by the firmware and even
> less are exposed via WMI.
>
> Signed-off-by: Thomas Weißschuh 
> ---
>  drivers/platform/x86/Kconfig|  11 +++
>  drivers/platform/x86/Makefile   |   1 +
>  drivers/platform/x86/gigabyte-wmi.c | 138 
>  3 files changed, 150 insertions(+)
>  create mode 100644 drivers/platform/x86/gigabyte-wmi.c
>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index ad4e630e73e2..96622a2106f7 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -123,6 +123,17 @@ config XIAOMI_WMI
> To compile this driver as a module, choose M here: the module will
> be called xiaomi-wmi.
>
> +config GIGABYTE_WMI
> + tristate "Gigabyte WMI temperature driver"
> + depends on ACPI_WMI
> + depends on HWMON
> + help
> +   Say Y here if you want to support WMI-based temperature reporting on
> +   Gigabyte mainboards.
> +
> +   To compile this driver as a module, choose M here: the module will
> +   be called gigabyte-wmi.
> +
>  config ACERHDF
>   tristate "Acer Aspire One temperature and fan driver"
>   depends on ACPI && THERMAL
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index 60d554073749..1621ebfd04fd 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_INTEL_WMI_THUNDERBOLT) += 
> intel-wmi-thunderbolt.o
>  obj-$(CONFIG_MXM_WMI)+= mxm-wmi.o
>  obj-$(CONFIG_PEAQ_WMI)   += peaq-wmi.o
>  obj-$(CONFIG_XIAOMI_WMI) += xiaomi-wmi.o
> +obj-$(CONFIG_GIGABYTE_WMI)   += gigabyte-wmi.o
>
>  # Acer
>  obj-$(CONFIG_ACERHDF)+= acerhdf.o
> diff --git a/drivers/platform/x86/gigabyte-wmi.c 
> b/drivers/platform/x86/gigabyte-wmi.c
> new file mode 100644
> index ..8618363e3ccf
> --- /dev/null
> +++ b/drivers/platform/x86/gigabyte-wmi.c
> @@ -0,0 +1,138 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + *  Copyright (C) 2021 Thomas Weißschuh 
> + */
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include 
> +#include 
> +#include 
> +#include 
> +
> +#define GIGABYTE_WMI_GUID "DEADBEEF-2001--00A0-C9062910"
> +
> +enum gigabyte_wmi_commandtype {
> + GIGABYTE_WMI_BUILD_DATE_QUERY   =   0x1,
> + GIGABYTE_WMI_MAINBOARD_TYPE_QUERY   =   0x2,
> + GIGABYTE_WMI_FIRMWARE_VERSION_QUERY =   0x4,
> + GIGABYTE_WMI_MAINBOARD_NAME_QUERY   =   0x5,
> + GIGABYTE_WMI_TEMPERATURE_QUERY  = 0x125,
> +};
> +
> +struct gigabyte_wmi_args {
> + u32 arg1;
> +};
> +
> +static int gigabyte_wmi_perform_query(enum gigabyte_wmi_commandtype command,
> + struct gigabyte_wmi_args *args, struct acpi_buffer *out)
> +{
> + const struct acpi_buffer in = {
> + .length = sizeof(*args),
> + .pointer = args,
> + };
> +
> + acpi_status ret = wmi_evaluate_method(GIGABYTE_WMI_GUID, 0x0, command, 
> , out);

Ideally, you'd use the WMI device that was passed to the probe method to do the 
query
using `wmidev_evaluate_method()`. You can pass the WMI device pointer
to `devm_hwmon_device_register_with_info()` in the `drvdata` argument,
then in the ->read() callback you can retrieve it:

  static int gigabyte_wmi_hwmon_read(struct device *dev, ...)
  {
struct wmi_device *wdev = dev_get_drvdata(dev);

and then you can pass that to the other functions.


> + if (ret == AE_OK) {
> + return 0;
> + } else {
> + return -EIO;
> + };

The `;` is not needed. And please use `ACPI_FAILURE()` or `ACPI_SUCCESS()`
to check the returned value. For example:

  acpi_status ret = ...;
  if (ACPI_FAILURE(ret))
return -EIO;

  return 0;


> +}
> +
> +static int gigabyte_wmi_query_integer(enum gigabyte_wmi_commandtype command,
> + struct gigabyte_wmi_args *args, u64 *res)
> +{
> + union acpi_object *obj;
> + struct acpi_buffer result = { ACPI_ALLOCATE_BUFFER, NULL };
> + int ret;
> +
> + ret = 

Re: [PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-07 Thread Hans de Goede
Hi Thomas,

Thank you for your new driver and thank you for the quick respin
addressing Barnabás' request to make it a WMI driver.

The code looks good, so merging this should be a no-brainer,
yet I'm not sure if I should merge this driver as-is, let me
explain.

The problem is that I assume that this is based on reverse-engineering?

We have some mixes experiences with reverse-engineered WMI drivers,
sometimes a feature is not supported yet the wmi_evaluate_method()
call happily succeeds. One example of this causing trouble is:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1797d588af15174d4a4e7159dac8c800538e4f8c

At a minimum I think your driver should check in its
probe function that

gigabyte_wmi_query_integer(GIGABYTE_WMI_TEMPERATURE_QUERY, ...)

actually succeeds on the machine the driver is running on chances
are that Gigabyte has been using the DEADBEEF-2001--00A0-C9062910
GUID for ages, where as the 0x125 value for GIGABYTE_WMI_TEMPERATURE_QUERY
suggests that this is a pretty new API.

It would be good if you can see if you can find some DSDT-s for older
gigabyte motherboards attached to various distro's bug-tracking systems
or forum posts and see how those respond to an unknown gigabyte_wmi_commandtype.

Another open question to make sure this driver is suitable
as a generic driver (and does not misbehave) is how to figure out
how many temperature sensors there actually are.

Perhaps the WMI interface returns an error when you query an out-of-range
temperature channel?

One option here might be to add a DMI matching table and only load on
systems on that table for now. That table could then perhaps also provide
labels for each of the temperature channels, which is something which
would be nice to have regardless of my worries about how well this driver
will work on motherboards on which it has not been tested.

You could combine this DMI matching table with a "force" module option to
continue with probing on boards which are not on the table to allow users
to test and report their results to you.

And hopefully after a while, when we're confident that the code works
well on most gigabyte boards we can drop the DMI table, or at least
only use it for the channel labels.

Please don't take this the wrong way; I think it is great that you are
working on this. And the quick turnaround of the v2 of this drivers makes
me pretty certain that we can figure something out and get this merged.

Have you tried contacting Gigabyte about this? I don't think the WMI
interface is something which they need to keep secret for competitive
reasons, so maybe they can help? Note if they want you to sign a NDA
of sorts to view docs, then make sure that it contains some language
about them allowing you to release an opensource driver for their
hardware based on the "protected" information.

Regards,

Hans









On 4/5/21 10:48 PM, Thomas Weißschuh wrote:
> Changes since v1:
> * Incorporate feedback from Barnabás Pőcze
>   * Use a WMI driver instead of a platform driver
>   * Let the kernel manage the driver lifecycle
>   * Fix errno/ACPI error confusion
>   * Fix resource cleanup
>   * Document reason for integer casting
> 
> Thank you Barnabás for your review, it is much appreciated.
> 
> -- >8 --
> 
> Tested with a X570 I Aorus Pro Wifi.
> The mainboard contains an ITE IT8688E chip for management.
> This chips is also handled by drivers/hwmon/i87.c but as it is also used
> by the firmware itself it needs an ACPI driver.
> 
> Unfortunately not all sensor registers are handled by the firmware and even
> less are exposed via WMI.
> 
> Signed-off-by: Thomas Weißschuh 
> ---
>  drivers/platform/x86/Kconfig|  11 +++
>  drivers/platform/x86/Makefile   |   1 +
>  drivers/platform/x86/gigabyte-wmi.c | 138 
>  3 files changed, 150 insertions(+)
>  create mode 100644 drivers/platform/x86/gigabyte-wmi.c
> 
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index ad4e630e73e2..96622a2106f7 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -123,6 +123,17 @@ config XIAOMI_WMI
> To compile this driver as a module, choose M here: the module will
> be called xiaomi-wmi.
>  
> +config GIGABYTE_WMI
> + tristate "Gigabyte WMI temperature driver"
> + depends on ACPI_WMI
> + depends on HWMON
> + help
> +   Say Y here if you want to support WMI-based temperature reporting on
> +   Gigabyte mainboards.
> +
> +   To compile this driver as a module, choose M here: the module will
> +   be called gigabyte-wmi.
> +
>  config ACERHDF
>   tristate "Acer Aspire One temperature and fan driver"
>   depends on ACPI && THERMAL
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index 60d554073749..1621ebfd04fd 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -15,6 +15,7 @@ 

[PATCH v2] platform/x86: add Gigabyte WMI temperature driver

2021-04-05 Thread Thomas Weißschuh
Changes since v1:
* Incorporate feedback from Barnabás Pőcze
  * Use a WMI driver instead of a platform driver
  * Let the kernel manage the driver lifecycle
  * Fix errno/ACPI error confusion
  * Fix resource cleanup
  * Document reason for integer casting

Thank you Barnabás for your review, it is much appreciated.

-- >8 --

Tested with a X570 I Aorus Pro Wifi.
The mainboard contains an ITE IT8688E chip for management.
This chips is also handled by drivers/hwmon/i87.c but as it is also used
by the firmware itself it needs an ACPI driver.

Unfortunately not all sensor registers are handled by the firmware and even
less are exposed via WMI.

Signed-off-by: Thomas Weißschuh 
---
 drivers/platform/x86/Kconfig|  11 +++
 drivers/platform/x86/Makefile   |   1 +
 drivers/platform/x86/gigabyte-wmi.c | 138 
 3 files changed, 150 insertions(+)
 create mode 100644 drivers/platform/x86/gigabyte-wmi.c

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index ad4e630e73e2..96622a2106f7 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -123,6 +123,17 @@ config XIAOMI_WMI
  To compile this driver as a module, choose M here: the module will
  be called xiaomi-wmi.
 
+config GIGABYTE_WMI
+   tristate "Gigabyte WMI temperature driver"
+   depends on ACPI_WMI
+   depends on HWMON
+   help
+ Say Y here if you want to support WMI-based temperature reporting on
+ Gigabyte mainboards.
+
+ To compile this driver as a module, choose M here: the module will
+ be called gigabyte-wmi.
+
 config ACERHDF
tristate "Acer Aspire One temperature and fan driver"
depends on ACPI && THERMAL
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 60d554073749..1621ebfd04fd 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_INTEL_WMI_THUNDERBOLT)   += 
intel-wmi-thunderbolt.o
 obj-$(CONFIG_MXM_WMI)  += mxm-wmi.o
 obj-$(CONFIG_PEAQ_WMI) += peaq-wmi.o
 obj-$(CONFIG_XIAOMI_WMI)   += xiaomi-wmi.o
+obj-$(CONFIG_GIGABYTE_WMI) += gigabyte-wmi.o
 
 # Acer
 obj-$(CONFIG_ACERHDF)  += acerhdf.o
diff --git a/drivers/platform/x86/gigabyte-wmi.c 
b/drivers/platform/x86/gigabyte-wmi.c
new file mode 100644
index ..8618363e3ccf
--- /dev/null
+++ b/drivers/platform/x86/gigabyte-wmi.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (C) 2021 Thomas Weißschuh 
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include 
+#include 
+#include 
+#include 
+
+#define GIGABYTE_WMI_GUID "DEADBEEF-2001--00A0-C9062910"
+
+enum gigabyte_wmi_commandtype {
+   GIGABYTE_WMI_BUILD_DATE_QUERY   =   0x1,
+   GIGABYTE_WMI_MAINBOARD_TYPE_QUERY   =   0x2,
+   GIGABYTE_WMI_FIRMWARE_VERSION_QUERY =   0x4,
+   GIGABYTE_WMI_MAINBOARD_NAME_QUERY   =   0x5,
+   GIGABYTE_WMI_TEMPERATURE_QUERY  = 0x125,
+};
+
+struct gigabyte_wmi_args {
+   u32 arg1;
+};
+
+static int gigabyte_wmi_perform_query(enum gigabyte_wmi_commandtype command,
+   struct gigabyte_wmi_args *args, struct acpi_buffer *out)
+{
+   const struct acpi_buffer in = {
+   .length = sizeof(*args),
+   .pointer = args,
+   };
+
+   acpi_status ret = wmi_evaluate_method(GIGABYTE_WMI_GUID, 0x0, command, 
, out);
+   if (ret == AE_OK) {
+   return 0;
+   } else {
+   return -EIO;
+   };
+}
+
+static int gigabyte_wmi_query_integer(enum gigabyte_wmi_commandtype command,
+   struct gigabyte_wmi_args *args, u64 *res)
+{
+   union acpi_object *obj;
+   struct acpi_buffer result = { ACPI_ALLOCATE_BUFFER, NULL };
+   int ret;
+
+   ret = gigabyte_wmi_perform_query(command, args, );
+   if (ret) {
+   goto out;
+   }
+   obj = result.pointer;
+   if (obj && obj->type == ACPI_TYPE_INTEGER) {
+   *res = obj->integer.value;
+   ret = 0;
+   } else {
+   ret = -EIO;
+   }
+out:
+   kfree(result.pointer);
+   return ret;
+}
+
+static int gigabyte_wmi_temperature(u8 sensor, long *res)
+{
+   struct gigabyte_wmi_args args = {
+   .arg1 = sensor,
+   };
+   u64 temp;
+   acpi_status ret;
+
+   ret = gigabyte_wmi_query_integer(GIGABYTE_WMI_TEMPERATURE_QUERY, , 
);
+   if (ret == 0)
+   *res = (s8) temp * 1000; // value is a signed 8-bit integer
+   return ret;
+}
+
+static int gigabyte_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types 
type,
+   u32 attr, int channel, long *val)
+{
+   return gigabyte_wmi_temperature(channel, val);
+}
+
+static umode_t gigabyte_wmi_hwmon_is_visible(const void *data, enum 
hwmon_sensor_types type,
+   u32 attr, int channel)
+{
+