On Wed, Dec 05, 2012 at 07:07:52AM +0000, Zheng, Lv wrote: > > On Tue, Dec 04, 2012 at 07:50:30PM +0000, Alan Cox wrote: > > > > And if we have enumerated the UART controller from ACPI (it is > > > > probably attached to the platform bus) we can find the tty device it > > > > exports like: > > > > > > The property should not be in any ACPI specific form or space - just > > > attach it directly to the tty from ACPI, DT, driver internal > > > knowledge, PCI id, whatever > > > > The only property that comes into mind is _HID/_CID (referring to the ACPI > > ID) that can be used by userspace to find out type of the device behind the > > UART port. I don't know what name would be generic enough for the property, > > though. > > > > There are other resources as well in addition to the UartSerialBus(). For > > example we might have two GPIO lines connected to the bluetooth chip and > > these are represented as GpioIo ACPI resources. > > > > Since the bluetooth is mostly handled by the N_HCI line discipline, should the > > GPIO handling be done there as well? It can distinguish between DT and ACPI > > enumerated devices by comparing dev->of_node and ACPI_HANDLE(dev) so it > > can get the resources from both DT and ACPI but I'm not sure if it really > > belongs there. Or should this be in a separate driver? > > IMO, > For ACPI enumerated target devices, ACPI can provide GPIO enumeration API > by feeding ACPI_HANDLE(tty->target) to obtain the GPIO resources while OF > can offer its own implementation. > Then there are 2 possible solutions can be found by calling such APIs: > 1. implement GPIO enabling in the kernel side N_HCI proto driver. > 2. implement GPIO enabling in the kernel side UART driver on TIOCSETD. OK. > Same issues can be found for the ACPI enumerated SPI/I2C target devices. > Thus the GpioIrq and GpioIo is not handled in this patch set. Yeah, I wasn't expecting that this series addresses that :-) However, this is something we need to solve at some point - we probably don't want that userspace deals with the GPIOs. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
