Hi Sylwester, On Tuesday 08 January 2013 12:37:36 Sylwester Nawrocki wrote: > On 01/08/2013 11:35 AM, Laurent Pinchart wrote: > >>>>> If we need a workaround, I'd rather pass the device name in addition > >>>>> to the I2C adapter number and address, instead of embedding the > >>>>> workaround in this new API. > >>>> > >>>> ...or we can change the I2C subdevice name format. The actual need to > >>>> do > >>>> > >>>> snprintf(clk_name, sizeof(clk_name), "%s %d-%04x", > >>>> asdl->dev->driver->name, > >>>> i2c_adapter_id(client->adapter), client->addr); > >>>> > >>>> in soc-camera now to exactly match the subdevice name, as created by > >>>> v4l2_i2c_subdev_init(), doesn't make me specifically happy either. What > >>>> if the latter changes at some point? Or what if one driver wishes to > >>>> create several subdevices for one I2C device? > >>> > >>> The common clock framework uses %d-%04x, maybe we could use that as well > >>> for clock names ? > >> > >> And preserve the subdevice names? Then matching would be more difficult > >> and less precise. Or change subdevice names too? I think, we can do the > >> latter, since anyway at any time only one driver can be attached to an > >> I2C device. > > > > That's right. Where else is the subdev name used ? > > Subdev names are exposed to user space by the media controller API. > So they are really part of an ABI, aren't they ? They're used to construct the name exposed to userspace, but the media controller core could probably handle that internally by concatenating the driver name and the subdev name. > Also having I2C bus number or I2C slave address as part of the subdev > name makes it more difficult to write portable applications. Hence > in sensor drivers I used to overwrite subdev name to remove I2C bus > and slave address, as the format used v4l2_i2c_subdev_init() seemed > highly unsuitable.. This clearly shows that we need to discuss the matter and agree on a common mode of operation. Aren't applications that use the subdev name directly inherently non-portable anyway ? If you want your application to support different boards/sensors/SoCs you should discover the pipeline and find the sensor by iterating over entities, instead of using the sensor entity name. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
