Re: [PATCH 12/15] i2c: core: Add new i2c_acpi_new_device helper function

[Hans de Goede]

Hi,

On 17-03-17 18:37, Andy Shevchenko wrote:
> On Fri, 2017-03-17 at 10:55 +0100, Hans de Goede wrote:
> > By default the i2c subsys creates an i2c-client for the first
> > I2cSerialBus
> > resource of an acpi_device, but some acpi_devices have multiple
> > I2cSerialBus resources and the driver may need access to the others.
> >
> > This commit adds a new i2c_acpi_new_device function which can be used
> > by
> > drivers to create an i2c-client for any (other) I2cSerialBus resource
> > of
> > an acpi_device.
> >
> > Note that the other resources may even be on a different i2c bus, so
> > just
> > retrieving the client address is not enough.
>
> Looks sane to me:
>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
>
> Nevertheless, one nit, can you update commit message with real excerpt
> of DSDT?

Sure, will do for v2.

Regards,

Hans


> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> > ---
> >  drivers/i2c/i2c-core.c | 48
> > ++++++++++++++++++++++++++++++++++++++++++++++++
> >  include/linux/i2c.h    |  5 +++++
> >  2 files changed, 53 insertions(+)
> >
> > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> > index 32b58fb..fd45207 100644
> > --- a/drivers/i2c/i2c-core.c
> > +++ b/drivers/i2c/i2c-core.c
> > @@ -421,6 +421,54 @@ static int i2c_acpi_notify(struct notifier_block
> > *nb, unsigned long value,
> >  static struct notifier_block i2c_acpi_notifier = {
> >  	.notifier_call = i2c_acpi_notify,
> >  };
> > +
> > +/**
> > + * i2c_acpi_new_device - Create i2c client for the Nth acpi resource
> > of dev
> > + * @dev:     Device owning the acpi resources to get the client from
> > + * @index:   Index of acpi resource to get
> > + *
> > + * By default the i2c subsys creates an i2c-client for the first
> > I2cSerialBus
> > + * resource of an acpi_device, but some acpi_devices have multiple
> > + * I2cSerialBus resources and the driver may need access to the
> > others.
> > + * This function can be used by drivers to create an i2c-client for
> > any
> > + * resource of an acpi_device.
> > + *
> > + * Returns a pointer to the new i2c-client, or NULL if the resource
> > or
> > + * adapter were not found.
> > + */
> > +struct i2c_client *i2c_acpi_new_device(struct device *dev, int index)
> > +{
> > +	struct i2c_acpi_lookup lookup;
> > +	struct i2c_board_info info;
> > +	struct i2c_adapter *adapter;
> > +	struct acpi_device *adev;
> > +	LIST_HEAD(resource_list);
> > +	int ret;
> > +
> > +	adev = ACPI_COMPANION(dev);
> > +	if (!adev)
> > +		return NULL;
> > +
> > +	memset(&info, 0, sizeof(info));
> > +	memset(&lookup, 0, sizeof(lookup));
> > +	lookup.info = &info;
> > +	lookup.device_handle = acpi_device_handle(adev);
> > +	lookup.index = index;
> > +
> > +	ret = acpi_dev_get_resources(adev, &resource_list,
> > +				     i2c_acpi_fill_info, &lookup);
> > +	acpi_dev_free_resource_list(&resource_list);
> > +
> > +	if (ret < 0 || !info.addr)
> > +		return NULL;
> > +
> > +	adapter =
> > i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
> > +	if (!adapter)
> > +		return NULL;
> > +
> > +	return i2c_new_device(adapter, &info);
> > +}
> > +EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
> >  #else /* CONFIG_ACPI */
> >  static inline void i2c_acpi_register_devices(struct i2c_adapter
> > *adap) { }
> >  extern struct notifier_block i2c_acpi_notifier;
> > diff --git a/include/linux/i2c.h b/include/linux/i2c.h
> > index 6b18352..369ebfa 100644
> > --- a/include/linux/i2c.h
> > +++ b/include/linux/i2c.h
> > @@ -824,11 +824,16 @@ static inline const struct of_device_id
> >
> >  #if IS_ENABLED(CONFIG_ACPI)
> >  u32 i2c_acpi_find_bus_speed(struct device *dev);
> > +struct i2c_client *i2c_acpi_new_device(struct device *dev, int
> > index);
> >  #else
> >  static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
> >  {
> >  	return 0;
> >  }
> > +static inline struct i2c_client *i2c_acpi_new_device(struct device
> > *d, int i)
> > +{
> > +	return NULL;
> > +}
> >  #endif /* CONFIG_ACPI */
> >
> >  #endif /* _LINUX_I2C_H */