On Wed, Aug 27, 2014 at 10:50 AM, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote: > On 08/27/2014 11:38 AM, Andrew Bresticker wrote: >> >> On Mon, Aug 25, 2014 at 12:01 PM, Stephen Warren <swarren@xxxxxxxxxxxxx> >> wrote: >>> >>> On 08/18/2014 11:08 AM, Andrew Bresticker wrote: >>>> >>>> +static int tegra_xusb_mbox_probe(struct platform_device *pdev) >>> >>> >>> >>>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >>>> >>>> + if (!res) >>>> + return -ENODEV; >>> >>> >>> >>> Should devm_request_mem_region() be called here to claim the region? >> >> >> No, the xHCI host driver also needs to map these registers, so they >> cannot be mapped exclusively here. > > > That's unfortunate. Having multiple drivers with overlapping register > regions is not a good idea. Can we instead have a top-level driver map all > the IO regions, then instantiate the various different sub-components > internally, and divide up the address space. Probably via MFD or similar. > That would prevent multiple drivers from touching the same register region. Perhaps I'm misunderstanding, but I don't see how MFD would prevent us from having to map this register space in two different locations - the XUSB FPCI address space cannot be divided cleanly between host and mailbox registers. Or are you saying that there should be a separate device driver that exposes an API for accessing this register space, like the Tegra fuse or PMC drivers? -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
