On Wednesday 10 October 2012 10:50:20 Stephen Warren wrote: > On 10/10/2012 07:18 AM, Laurent Pinchart wrote: > > On Monday 08 October 2012 17:15:53 Guennadi Liakhovetski wrote: > ... > > >> But how do you get the subdev pointer? With the notifier I get it from > >> i2c_get_clientdata(client) and what do you do without it? How do you get > >> to the client? > >> > >>> And can't it get that from DT as well? > >> > >> No, I don't think there is a way to get a device pointer from a DT node. > > I don't believe there's a generic API for this (although perhaps there > could be), but it can be implemented quite easily. > > For example, on Tegra, the SMMU needs to flip a bit in the AHB register > space in order to enable itself. The SMMU DT node contains a phandle > that points at the AHB DT node. The SMMU driver parses the phandle and > passes the DT node pointer to the AHB driver. The AHB driver looks up > the struct device that was instantiated for that node. See > drivers/amba/tegra-ahb.c:tegra_ahb_enable_smmu(). There are a few other > cases of similar code in the kernel, although I can't remember the others! That's a very naive approach, but what about storing the struct device in struct device_node when the device is instantiated ? It's so simple that there's probably a good reason why that hasn't been implemented though. -- 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
