From d21f68bbd588f46c23066eb8d227b51e4823de41 Mon Sep 17 00:00:00 2001 From: Patrick Georgi Date: Tue, 2 Sep 2008 16:06:22 +0000 Subject: This patch adds USB capabilities to libpayload. It requires some memalign implementation (eg. the one I sent yesterday). Features: - UHCI controller driver - UHCI root hub driver - USB MSC (Mass Storage Class) driver - skeleton of a USB HID driver (requires better interrupt transfer handling, which is TODO) - skeleton of a USB hub driver (needs several blank spots filled in, eg. power management. Again: TODO) OHCI and EHCI are not supported, though OHCI support should be rather easy as the stack provides reasonable abstractions (or so I hope). EHCI will probably be more complicated. Isochronous transfers (eg. webcams, audio stuff, ...) are not supported. They can be, but I doubt we'll have a reason for that in the boot environment. The MSC driver was tested against a couple of USB flash drives, and should be reasonably tolerant by now. But I probably underestimate the amount of bugs present in USB flash drives, so feedback is welcome. Signed-off-by: Patrick Georgi Acked-by: Jordan Crouse git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3560 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1 --- payloads/libpayload/drivers/usb/TODO | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 payloads/libpayload/drivers/usb/TODO (limited to 'payloads/libpayload/drivers/usb/TODO') diff --git a/payloads/libpayload/drivers/usb/TODO b/payloads/libpayload/drivers/usb/TODO new file mode 100644 index 0000000000..1dfc9d40ab --- /dev/null +++ b/payloads/libpayload/drivers/usb/TODO @@ -0,0 +1,22 @@ +- handle error conditions +- handle disconnect more gracefully (ie. make calling layer aware that the device doesn't exist somehow) +- usbhub: + - proper client enumeration (esp. detach) + - change detection + - power management +- handle interrupts more cleverly: + create a new queue for the interrupt with a couple of TD sequences, + - each ending with "breadth first" flag + - linked as a chain + add that queue at the appropriate times in front of the default structure so the max latency is honored + - only one intr chain per framelist item, so it must be arranged appropriately + reads from usb device just look at "invalidated" tds and the results they got + handled tds get reactivated as a ring structure + - added as child of the oldest td + - queue header already dropped the td, so no issue there + + this setup ensures that: + - the max latency of the device is honored + - the client knows the right order of the data + - there is no need for an interrupt handler + - but must be polled at least max latency * num tds times -> more tds = less time pressure -- cgit v1.2.3