On Thu, Jul 21, 2011 at 04:52:18PM -0700, Kevin Hilman wrote: > Rather than embedding a struct platform_device inside a struct > omap_device, decouple them, leaving only a pointer to the > platform_device inside the omap_device. > > This patch uses devres to allocate and attach the omap_device to the > struct device, so finding an omap_device from a struct device means > using devres_find(), and the to_omap_device() helper function was > modified accordingly. > > RFC/Hack alert: > > Currently the driver core (drivers/base/dd.c) doesn't expect any > devres resources to exist before the driver's ->probe() is called. In > this patch, I just comment out the warning, but we'll need to > understand why that limitation exists, and if it's a real limitation. > A first glance suggests that it's not really needed. If this is a > true limitation, we'll need to find some way other than devres to > attach an omap_device to a struct device. > > On OMAP, we will need an omap_device attached to a struct device > before probe because device HW may be disabled in probe and drivers > are expected to use runtime PM in ->probe() to activate the hardware > before access. Because the runtime PM API calls use omap_device (via > our PM domain layer), we need omap_device attached to a > platform_device before probe. This feels really wrong to overload devres with this. devres purpose is to provide the device's _drivers_ with a way to allocate and free resources in such a way to avoid leaks on .remove or probe failure. So I think that overloading it with something that has a different lifetime is completely wrong. We could add a new member to struct dev_archdata or pdev_archdata to carry a pointer to this data, which I think would be a far cleaner (and saner) way to deal with this. In much the same way as we already have an of_node member in struct device. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
