Date:   Mon, 30 Jan 2023 12:31:13 +0000
From:   Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To:     Darrell Kavanagh <darrell.kavanagh@gmail.com>
CC:     <linux-iio@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: Bug#1029850: linux: Driver not loaded for ST Microelectronics
 LSM6DS3TR-C accelerometer (acpi:SMO8B30:SMO8B30:)
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On Mon, 30 Jan 2023 03:37:23 +0000
Darrell Kavanagh <darrell.kavanagh@gmail.com> wrote:

> Forwarding because original html messages were rejected by the server...
> 
> ---------- Forwarded message ---------
> From: Darrell Kavanagh <darrell.kavanagh@gmail.com>
> Date: Mon, 30 Jan 2023 at 02:52
> Subject: Re: Bug#1029850: linux: Driver not loaded for ST
> Microelectronics LSM6DS3TR-C accelerometer (acpi:SMO8B30:SMO8B30:)
> To: Jonathan Cameron <jic23@kernel.org>
> Cc: <lorenzo@kernel.org>, <lars@metafoo.de>,
> <linux-iio@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
> <carnil@debian.org>
> 
> 
> Hi Jonathan,
> 
> Thank you. The driver has evolved quite a bit in 6.2 (I read somewhere
> that 6.2 includes some i2c enhancements), but I adapted your changes
> to fit my Debian 6.1 kernel and it works. Two IIO devices are created
> in sysfs, iio-sensor-proxy.service starts up and automatic screen
> rotation in Gnome just works.
> 
> To get the modules to load on boot, I made a small change to your code
> in st_lsm6dsx_i2c to add the acpi alias to modules.alias:
> 
> adding a null element to st_lsm6dsx_i2c_acpi_match:
>     static const struct acpi_device_id st_lsm6dsx_i2c_acpi_match[] = {
>          { "SMO8B30", ST_LSM6DS3TRC_ID, },
>          { },
>     };
> then:
>    MODULE_DEVICE_TABLE(acpi, st_lsm6dsx_i2c_acpi_match);

doh! That was indeed sloppy of me to miss even for an untested hack.


> 
> 
> dmesg shows:
> 
> [ 7366.120208] st_lsm6dsx_i2c i2c-SMO8B30:00: supply vdd not found,
> using dummy regulator
> [ 7366.120260] st_lsm6dsx_i2c i2c-SMO8B30:00: supply vddio not found,
> using dummy regulator
> [ 7366.650839] st_lsm6dsx_i2c i2c-SMO8B30:00: mounting matrix not
> found: using identity...
> 
> Is this a problem?

Those are all fine. For regulators that's expected on ACPI and should
be harmless as it's up to the firmware to manage power (in DT it may
be up to the kernel).
For the mounting matrix, there is often something in ACPI DSDT
(non standard though).  Could you
cat /sys/firmware/acpi/tables/DSDT > ~/dsdt
then run through iasl from acpitools
iasl -d ~/dsdt
and find the bit related to this device.

If you can then share that there may be a _DSM or similar in there that
is effectively the mounting matrix.  If we are lucky it will look like
some existing versions we have code to handle and can add that support
as well.

Either way - I'll spin a formal patch with your fixes above and we can
get this upstream for future kernels.  Mounting matrix can follow
later if needed.

Thanks,

Jonathan


> 
> Thanks again.
> 
> Darrell
> 
> 
> On Sun, 29 Jan 2023 at 18:10, Jonathan Cameron <jic23@kernel.org> wrote:
> >
> > On Sun, 29 Jan 2023 17:03:51 +0000
> > Darrell Kavanagh <darrell.kavanagh@gmail.com> wrote:
> >  
> > > Hi,
> > >
> > > I raised this bug in Debian, and have been asked to raise it upstream and
> > > was given your addresses to do so. Will this email be OK, or should I raise
> > > it in a bug tracking system somewhere?  
> >
> > Email is the right option.
> >  
> > >
> > > Many thanks,
> > > Darrell
> > >
> > >
> > >
> > >
> > > ---------- Forwarded message ---------
> > > From: Salvatore Bonaccorso <carnil@debian.org>
> > > Date: Sat, 28 Jan 2023 at 20:33
> > > Subject: Re: Bug#1029850: linux: Driver not loaded for ST Microelectronics
> > > LSM6DS3TR-C accelerometer (acpi:SMO8B30:SMO8B30:)
> > > To: Darrell Kavanagh <darrell.kavanagh@gmail.com>, <1029850@bugs.debian.org>
> > >
> > >
> > > Hi Darrell,
> > >
> > > On Sat, Jan 28, 2023 at 08:13:16PM +0000, Darrell Kavanagh wrote:  
> > > > Package: src:linux
> > > > Version: 6.1.4-1
> > > > Severity: normal
> > > > File: linux
> > > > X-Debbugs-Cc: darrell.kavanagh@gmail.com
> > > >
> > > > Dear Maintainer,
> > > >
> > > > This is a convertable touchscreen tablet/laptop. The rotation sensor  
> > > device  
> > > > ST Microelectronics LSM6DS3TR-C does not work. It is detected via ACPI  
> > > and the  
> > > > sysfs trees are created at  
> > > devices/pci0000:00/0000:00:17.1/i2c_designware.3/i2c-4/i2c-SMO8B30:00  
> > > > and devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:3c/SMO8B30:00 with
> > > > symlinks bus/acpi/devices/SMO8B30:00 and bus/i2c/devices/i2c-SMO8B30:00,  
> > > but  
> > > > no driver is loaded.  
> >
> > At least this is using the ST PNP ID which is better than average
> > (long story!)
> >
> > The driver in question (ultimately drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i2c.c
> > does not currently have an ACPI support.  It should be straight forwards
> > to add though the driver first needs converting to use
> > device_get_match_data() with appropriate fallback so that it will match on
> > ACPI, OF or original spi_device_id tables
> >
> > Completely untested but something like the following
> > (the offset in the enum is needed to allow us to tell if we got a result when
> > calling device_get_match_data() as it returns NULL on failure IIRC)
> >
> > I'm not sure how sucessful the driver will be at finding any interrupts etc, but
> > it may get you basic functionality.
> >
> > Good luck and others more familiar with the driver may well tell me what I forgot
> > when hacking the below ;)
> >
> > diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
> > index 499fcf8875b4..2617ce236ddc 100644
> > --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
> > +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
> > @@ -39,7 +39,7 @@
> >  #define ST_ISM330IS_DEV_NAME   "ism330is"
> >
> >  enum st_lsm6dsx_hw_id {
> > -       ST_LSM6DS3_ID,
> > +       ST_LSM6DS3_ID = 1,
> >         ST_LSM6DS3H_ID,
> >         ST_LSM6DSL_ID,
> >         ST_LSM6DSM_ID,
> > diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i2c.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i2c.c
> > index df5f60925260..ecfceb2fb3db 100644
> > --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i2c.c
> > +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i2c.c
> > @@ -23,10 +23,15 @@ static const struct regmap_config st_lsm6dsx_i2c_regmap_config = {
> >
> >  static int st_lsm6dsx_i2c_probe(struct i2c_client *client)
> >  {
> > -       const struct i2c_device_id *id = i2c_client_get_device_id(client);
> > -       int hw_id = id->driver_data;
> > +       int hw_id;
> >         struct regmap *regmap;
> >
> > +       hw_id = (kernel_ulong_t)device_get_match_data(&client->dev);
> > +       if (!hw_id)
> > +               hw_id = i2c_client_get_device_id(client)->driver_data;
> > +       if (!hw_id)
> > +               return -EINVAL;
> > +
> >         regmap = devm_regmap_init_i2c(client, &st_lsm6dsx_i2c_regmap_config);
> >         if (IS_ERR(regmap)) {
> >                 dev_err(&client->dev, "Failed to register i2c regmap %ld\n", PTR_ERR(regmap));
> > @@ -129,6 +134,10 @@ static const struct of_device_id st_lsm6dsx_i2c_of_match[] = {
> >  };
> >  MODULE_DEVICE_TABLE(of, st_lsm6dsx_i2c_of_match);
> >
> > +static const struct acpi_device_id st_lsm6dsx_i2c_acpi_match[] = {
> > +       { "SMO8B30", ST_LSM6DS3TRC_ID, },
> > +};
> > +
> >  static const struct i2c_device_id st_lsm6dsx_i2c_id_table[] = {
> >         { ST_LSM6DS3_DEV_NAME, ST_LSM6DS3_ID },
> >         { ST_LSM6DS3H_DEV_NAME, ST_LSM6DS3H_ID },
> > @@ -161,6 +170,7 @@ static struct i2c_driver st_lsm6dsx_driver = {
> >                 .name = "st_lsm6dsx_i2c",
> >                 .pm = pm_sleep_ptr(&st_lsm6dsx_pm_ops),
> >                 .of_match_table = st_lsm6dsx_i2c_of_match,
> > +               .acpi_match_table = st_lsm6dsx_i2c_acpi_match,
> >         },
> >         .probe_new = st_lsm6dsx_i2c_probe,
> >         .id_table = st_lsm6dsx_i2c_id_table,
> >
> >  
> > > >
> > > > The device is identifying itself to the kernel with PNP id SMO8B30:
> > > > physical_node:
> > > >       modalias=acpi:SMO8B30:SMO8B30:
> > > >       name=SMO8B30:00
> > > >       uevent=MODALIAS=acpi:SMO8B30:SMO8B30:
> > > >       waiting_for_supplier=0
> > > > firmware_node:
> > > >       hid=SMO8B30
> > > >       modalias=acpi:SMO8B30:SMO8B30:
> > > >       path=\_SB_.PCI0.I2C5.DEV_
> > > >       status=15
> > > >       uevent=MODALIAS=acpi:SMO8B30:SMO8B30:
> > > >       uid=0
> > > >
> > > > The kernel module for the appropriate driver (st_lsm6dsx_i2c) is not  
> > > loaded on boot.  
> > > > Modprobing it does not associate it with the device, as I would expect as
> > > > the module does not provide an alias for the above acpi/pnp id.  
> > >
> > > Can you report this issue upstream? Gues to reach out are according to
> > > get_maintainers.pl script:
> > >
> > > Lorenzo Bianconi <lorenzo@kernel.org> (maintainer:ST LSM6DSx IMU IIO DRIVER)
> > > Jonathan Cameron <jic23@kernel.org> (maintainer:IIO SUBSYSTEM AND DRIVERS)
> > > Lars-Peter Clausen <lars@metafoo.de> (reviewer:IIO SUBSYSTEM AND DRIVERS)
> > > linux-iio@vger.kernel.org (open list:ST LSM6DSx IMU IIO DRIVER)
> > > linux-kernel@vger.kernel.org (open list)
> > >
> > > Please keep us in the loop.
> > >
> > > Regards,
> > > Salvatore  
> >