[PATCH] i2c: designware: platdrv: Set class based on dmi

[PATCH] i2c: designware: platdrv: Set class based on dmi

[Ricardo Ribalda]

Current AMD's zen-based APUs use this core for some of its i2c-buses.

With this patch we re-enable autodetection of hwmon-alike devices, so
lm-sensors will be able to work automatically.

It does not affect the boot-time of embedded devices, as the class is
set based on the dmi information.

Signed-off-by: Ricardo Ribalda <ribalda@kernel.org>
---
 drivers/i2c/busses/i2c-designware-platdrv.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index c2efaaaac252..f0a02fc3c135 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -191,6 +191,13 @@ static int dw_i2c_plat_request_regs(struct dw_i2c_dev *dev)
 	return ret;
 }
 
+static bool dw_i2c_hwmon_bus(void)
+{
+	if (strstr(dmi_get_system_info(DMI_PRODUCT_NAME), "QT5222"))
+		return true;
+	return false;
+}
+
 static int dw_i2c_plat_probe(struct platform_device *pdev)
 {
 	struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
@@ -267,7 +274,8 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 
 	adap = &dev->adapter;
 	adap->owner = THIS_MODULE;
-	adap->class = I2C_CLASS_DEPRECATED;
+	adap->class = dw_i2c_hwmon_bus() ? I2C_CLASS_HWMON
+					 : I2C_CLASS_DEPRECATED;
 	ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 	adap->dev.of_node = pdev->dev.of_node;
 	adap->nr = -1;
-- 
2.27.0

Re: [PATCH] i2c: designware: platdrv: Set class based on dmi

[Andy Shevchenko]

On Wed, Jun 24, 2020 at 11:12:39AM +0200, Ricardo Ribalda wrote:
> Current AMD's zen-based APUs use this core for some of its i2c-buses.
> 
> With this patch we re-enable autodetection of hwmon-alike devices, so
> lm-sensors will be able to work automatically.
> 
> It does not affect the boot-time of embedded devices, as the class is
> set based on the dmi information.

Hmm... Do we really need to have DMI? I mean wouldn't be safe just always
provide this to be compatible with HWMON class?

...

> +static bool dw_i2c_hwmon_bus(void)
> +{
> +	if (strstr(dmi_get_system_info(DMI_PRODUCT_NAME), "QT5222"))
> +		return true;
> +	return false;
> +}

I don't like this. Perhaps for now you may simple use dmi_get_system_info()
directly below.

...

> +	adap->class = dw_i2c_hwmon_bus() ? I2C_CLASS_HWMON
> +					 : I2C_CLASS_DEPRECATED;

It's one line.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH] i2c: designware: platdrv: Set class based on dmi

[kernel test robot]

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Hi Ricardo,

I love your patch! Yet something to improve:

[auto build test ERROR on wsa/i2c/for-next]
[also build test ERROR on v5.8-rc2 next-20200624]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Ricardo-Ribalda/i2c-designware-platdrv-Set-class-based-on-dmi/20200624-171557
base:   https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git i2c/for-next
config: arc-allyesconfig (attached as .config)
compiler: arc-elf-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All error/warnings (new ones prefixed by >>):

   drivers/i2c/busses/i2c-designware-platdrv.c: In function 'dw_i2c_hwmon_bus':
>> drivers/i2c/busses/i2c-designware-platdrv.c:196:13: error: implicit declaration of function 'dmi_get_system_info'; did you mean 'acpi_get_system_info'? [-Werror=implicit-function-declaration]
     196 |  if (strstr(dmi_get_system_info(DMI_PRODUCT_NAME), "QT5222"))
         |             ^~~~~~~~~~~~~~~~~~~
         |             acpi_get_system_info
>> drivers/i2c/busses/i2c-designware-platdrv.c:196:13: warning: passing argument 1 of 'strstr' makes pointer from integer without a cast [-Wint-conversion]
     196 |  if (strstr(dmi_get_system_info(DMI_PRODUCT_NAME), "QT5222"))
         |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         |             |
         |             int
   In file included from include/linux/bitmap.h:9,
                    from include/linux/cpumask.h:12,
                    from include/linux/rcupdate.h:31,
                    from include/linux/radix-tree.h:15,
                    from include/linux/idr.h:15,
                    from include/linux/kernfs.h:13,
                    from include/linux/sysfs.h:16,
                    from include/linux/kobject.h:20,
                    from include/linux/of.h:17,
                    from include/linux/irqdomain.h:35,
                    from include/linux/acpi.h:13,
                    from drivers/i2c/busses/i2c-designware-platdrv.c:11:
   include/linux/string.h:82:15: note: expected 'const char *' but argument is of type 'int'
      82 | extern char * strstr(const char *, const char *);
         |               ^~~~~~
   cc1: some warnings being treated as errors

vim +196 drivers/i2c/busses/i2c-designware-platdrv.c

   193	
   194	static bool dw_i2c_hwmon_bus(void)
   195	{
 > 196		if (strstr(dmi_get_system_info(DMI_PRODUCT_NAME), "QT5222"))
   197			return true;
   198		return false;
   199	}
   200	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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Re: [PATCH] i2c: designware: platdrv: Set class based on dmi

[Wolfram Sang]

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On Wed, Jun 24, 2020 at 01:46:55PM +0300, Andy Shevchenko wrote:
> On Wed, Jun 24, 2020 at 11:12:39AM +0200, Ricardo Ribalda wrote:
> > Current AMD's zen-based APUs use this core for some of its i2c-buses.
> > 
> > With this patch we re-enable autodetection of hwmon-alike devices, so
> > lm-sensors will be able to work automatically.
> > 
> > It does not affect the boot-time of embedded devices, as the class is
> > set based on the dmi information.
> 
> Hmm... Do we really need to have DMI? I mean wouldn't be safe just always
> provide this to be compatible with HWMON class?

It is not unsafe. Embedded people might complain about increased boot
time whenever a CLASS_HWMON driver scans the addresses it knows.


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Re: [PATCH] i2c: designware: platdrv: Set class based on dmi

[Ricardo Ribalda Delgado]

Hi Andy

On Wed, Jun 24, 2020 at 12:46 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Wed, Jun 24, 2020 at 11:12:39AM +0200, Ricardo Ribalda wrote:
> > Current AMD's zen-based APUs use this core for some of its i2c-buses.
> >
> > With this patch we re-enable autodetection of hwmon-alike devices, so
> > lm-sensors will be able to work automatically.
> >
> > It does not affect the boot-time of embedded devices, as the class is
> > set based on the dmi information.
>
> Hmm... Do we really need to have DMI? I mean wouldn't be safe just always
> provide this to be compatible with HWMON class?
>

I do not care :), I was just trying to follow the logic of
70fba8302adecfa08a087c6f1dd39537a55f5bd3

If it is decided otherwise I can change it, no problem ;)

> ...
>
> > +static bool dw_i2c_hwmon_bus(void)
> > +{
> > +     if (strstr(dmi_get_system_info(DMI_PRODUCT_NAME), "QT5222"))
> > +             return true;
> > +     return false;
> > +}
>
> I don't like this. Perhaps for now you may simple use dmi_get_system_info()
> directly below.

I just realised that if there is no DMI, then we get a NULL, so we
need to add that check.

With the two ifs, I still prefer to put it on other function like now
(check v2).

If you still dont like it I will move it into the main function.

>
> ...
>
> > +     adap->class = dw_i2c_hwmon_bus() ? I2C_CLASS_HWMON
> > +                                      : I2C_CLASS_DEPRECATED;
>
> It's one line.

Fixed thanks
>
> --
> With Best Regards,
> Andy Shevchenko
>
>

Re: [PATCH] i2c: designware: platdrv: Set class based on dmi

[Andy Shevchenko]

On Wed, Jun 24, 2020 at 01:31:06PM +0200, Ricardo Ribalda Delgado wrote:
> On Wed, Jun 24, 2020 at 12:46 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> >
> > On Wed, Jun 24, 2020 at 11:12:39AM +0200, Ricardo Ribalda wrote:
> > > Current AMD's zen-based APUs use this core for some of its i2c-buses.
> > >
> > > With this patch we re-enable autodetection of hwmon-alike devices, so
> > > lm-sensors will be able to work automatically.
> > >
> > > It does not affect the boot-time of embedded devices, as the class is
> > > set based on the dmi information.
> >
> > Hmm... Do we really need to have DMI? I mean wouldn't be safe just always
> > provide this to be compatible with HWMON class?
> >
> 
> I do not care :), I was just trying to follow the logic of
> 70fba8302adecfa08a087c6f1dd39537a55f5bd3
> 
> If it is decided otherwise I can change it, no problem ;)

I guess you need to send a kinda revert with a fixes tag.

-- 
With Best Regards,
Andy Shevchenko