Re: [patch 2.6.24-rc1] resource_len() utility function

From: Jeff Garzik
Date: Wed Oct 24 2007 - 22:08:34 EST


Alan Cox wrote:
On Wed, 24 Oct 2007 18:20:52 -0700
David Brownell <david-b@xxxxxxxxxxx> wrote:

Add a new resource_len() function, so drivers can start using this
instead of driver-private code for a common idiom. The call can be
useful with at least:

- request_region(), release_region()
- request_mem_region(), release_mem_region()
- ioremap()

Candidate drivers include those using platform or PNP busses, and
maybe some others. PCI already has a similar function.

This patch also updates a representative set of drivers in two
subsystems to use this call (SPI, and USB peripheral/gadget).

PCI also increasingly is using functions that allow the user to choose to
map a resource as a resource (eg pci_iomap). So is it better to have
functions request_mem_resource(res) free_mem_resource(res) and similar
instead or as well ?


With regards to resource reservation... IMO we should mimic struct pci_dev and add struct resource[] to struct device.

Just like we have pci_request_regions(), we should also be able to easily to a dev_request_regions(). the implementation should be very close to pci_request_region() and pci_release_region().

Then a dev_iomap() analogue to pci_iomap() should be pretty straightforward to create.

Jeff


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/