Messages in this thread | | | Date | Tue, 12 Feb 2008 13:31:50 -0500 | From | Jeff Garzik <> | Subject | Re: multiple drivers, single device (was Re: Announce: Linux-next (Or Andrew's dream :-))) |
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Greg KH wrote: > Except that the individual drivers are a lot of the time written by > different people, live in different portions of the tree, and are > combined into different combinations depending on the chipset.
Yes -- the worst case is that people have to work together, and it tweaks people who like to organize source files nicely into directories :)
> For i2c devices, I see the scx200_acb, i2c-elektor, i2c-sis5595, and > i2c-sis630 drivers needing this. The last one happens to share the pci > device with a video driver, that doesn't always need to be / want to be > loaded by users just so they can read the temperature of their > processors.
Sure. Reasonable request, and doable within today's APIs.
> Oh, the EDAC code also needs this, and I know that no one wants to merge > that stuff into their individual drivers :)
So people have to work together... darn :) most drivers these days are organized nicely into nicely modular units anyway, making it easy to write a "shell" driver that simply registers each sub-driver, and helps arbitrate/provide resources to sub-units.
Consider, for example, a PCI driver that loads, and then fills in platform_data to provide a specific set of resources to a platform driver (a common idiom). You would need to create parented struct devices (parent: pci_dev's device), but everything else should work within
I could even forsee a future where most drivers are written in a generic platform-driver style, and PCI|sbus|embedded-bus|blah are simply bus-specific shells that fill in platform data.
All of this should be nicely possible within the existing usage of struct device, platform drivers, generic DMA API, iomap, etc.
Jeff
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