Re: [PATCH v3 4/4] i2c: Add multi-instantiate pseudo driver

[Hans de Goede]

Hi,

On 07-08-18 14:46, John Garry wrote:
> On 07/08/2018 09:05, Hans de Goede wrote:
> > On systems with ACPI instantiated i2c-clients, normally there is 1 fw_node
> > per i2c-device and that fw-node contains 1 I2cSerialBus resource for that 1
> > i2c-device.
> >
> > But in some rare cases the manufacturer has decided to describe multiple
> > i2c-devices in a single ACPI fwnode with multiple I2cSerialBus resources.
> >
> > An earlier attempt to fix this in the i2c-core resulted in a lot of extra
> > code to support this corner-case.
> >
> > This commit introduces a new i2c-multi-instantiate driver which fixes this
> > in a different way. This new driver can be built as a module which will
> > only loaded on affected systems.
> >
> > This driver will instantiate a new i2c-client per I2cSerialBus resource,
> > using the driver_data from the acpi_device_id it is binding to to tell it
> > which chip-type (and optional irq-resource) to use when instantiating.
> >
> > Note this driver depends on a platform device being instantiated for the
> > ACPI fwnode, see the i2c_multi_instantiate_ids list of ACPI device-ids in
> > drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
> >
> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> > ---
> >  MAINTAINERS                                  |   6 +
> >  drivers/platform/x86/Kconfig                 |  11 ++
> >  drivers/platform/x86/Makefile                |   1 +
> >  drivers/platform/x86/i2c-multi-instantiate.c | 131 +++++++++++++++++++
> >  4 files changed, 149 insertions(+)
> >  create mode 100644 drivers/platform/x86/i2c-multi-instantiate.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 9b377508f24f..09e16d76cab7 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -6657,6 +6657,12 @@ F:    drivers/i2c/i2c-mux.c
> >  F:    drivers/i2c/muxes/
> >  F:    include/linux/i2c-mux.h
> >
> > +I2C MULTI INSTANTIATE DRIVER
> > +M:    Hans de Goede <hdegoede@xxxxxxxxxx>
> > +L:    linux-i2c@xxxxxxxxxxxxxxx
> > +S:    Maintained
> > +F:    drivers/drivers/platform/x86/i2c-multi-instantiate.c
>
> This path looks incorrect
>
> > +
> >  I2C MV64XXX MARVELL AND ALLWINNER DRIVER
> >  M:    Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>
> >  L:    linux-i2c@xxxxxxxxxxxxxxx
> > diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> > index 85a93453237c..8256629f58f7 100644
> > --- a/drivers/platform/x86/Kconfig
> > +++ b/drivers/platform/x86/Kconfig
> > @@ -1219,6 +1219,17 @@ config INTEL_CHTDC_TI_PWRBTN
> >        To compile this driver as a module, choose M here: the module
> >        will be called intel_chtdc_ti_pwrbtn.
> >
> > +config I2C_MULTI_INSTANTIATE
> > +    tristate "I2C multi instantiate pseudo device driver"
> > +    depends on I2C && ACPI
> > +    help
> > +      Some ACPI bases systems list multiple i2c-devices in a single ACPI
>
> I guess that this should be "Some ACPI-based systems"

Thanks, both fixed for v4 of the patchset.

Regards,

Hans


> > +      firmware-node. This driver will instantiate separate i2c-clients
> > +      for each device in the firmware-node.
> > +
> > +      To compile this driver as a module, choose M here: the module
> > +      will be called i2c-multi-instantiate.
> > +
>
> Thanks,
> John