Hi Hans, On Wednesday 07 July 2010 15:04:17 Hans Verkuil wrote: > > On Wednesday 07 July 2010 14:30:45 Hans Verkuil wrote: [snip] > > Some (most ?) I2C sensors need to be accessed during probe. This involves > > powering the sensor up, which is handled by a board code function called > > through a platform data function pointer. > > > > On the OMAP3 ISP the sensor clock can be generated by the ISP. This means > > that board code needs to call an ISP (exported) function to turn the clock > > on. To do so we currently retrieve a pointer to the ISP device through the > > subdev's parent v4l2_device, embedded in the ISP device structure. This > > requires the subdev to be registered, otherwise its parent will be NULL. > > For that reason we're still using the core::s_config operation. > > > > This is obviously not an ideal situation, and I'm open to suggestions on > > how to solve it without core::s_config. One possibility would be to use a > > global ISP device pointer in the board code, as there's only one ISP > > device in the system. It feels a bit hackish though. > > Or make the v4l2_device pointer part of the platform data? That way the > subdev driver has access to the v4l2_device pointer in a fairly clean > manner. As we've discussed on IRC, the platform data should really store hardware properties, not software/driver information. Beside, storing the v4l2_device pointer in the platform data would be quite difficult, as v4l2_device_register_subdev only sees a void * pointer for platform_data. It has no knowledge of the device-specific structure. -- 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
