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ab7d219294
Preparing for isochronous transfers support adding in DDMA mode. In DDMA isochronous transfers are handled differently compared to Slave and BDMA modes. This is caused by fact that isoc requests contain data for one frame/microframe. HW descriptor should contain data of one frame/microframe as well. Hence each DMA descriptor in the chain will correspond to one usb request. Decided to divide endpoints descriptor chain to two halves - while one will be processed by HW, other one will be under SW control. First part will be passed to HW once ISOC traffic needs to be started. In parallel to HW's work SW will keep creating new entries in the other half of chain if new requests arrive in ep_queue routine. This will allow passing of already pre-prepared descriptors to HW immediately after endpoint gets disabled. The endpoint should be disabled once HW closes descriptor with "L" bit set. Afterwards SW will switch to use first part of chain if more requests are arriving. Add two members to the dwc2_hsotg_ep structure to be used in isochronous transfers' handling in DDMA mode: -isoc_chain_num - indicates which half of EP descriptor chain can be used by SW to add new queued requests while HW is processing other half. -next_desc - index which points to next not yet programmed descriptor in the half of descriptor chain which is under SW control. Also add initialization of these fields in function dwc2_hsotg_ep_enable(). Signed-off-by: Vahram Aharonyan <vahrama@synopsys.com> Signed-off-by: John Youn <johnyoun@synopsys.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> |
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| c67x00 | ||
| chipidea | ||
| class | ||
| common | ||
| core | ||
| dwc2 | ||
| dwc3 | ||
| early | ||
| gadget | ||
| host | ||
| image | ||
| isp1760 | ||
| misc | ||
| mon | ||
| musb | ||
| phy | ||
| renesas_usbhs | ||
| serial | ||
| storage | ||
| usbip | ||
| wusbcore | ||
| Kconfig | ||
| Makefile | ||
| README | ||
| usb-skeleton.c | ||
To understand all the Linux-USB framework, you'll use these resources:
* This source code. This is necessarily an evolving work, and
includes kerneldoc that should help you get a current overview.
("make pdfdocs", and then look at "usb.pdf" for host side and
"gadget.pdf" for peripheral side.) Also, Documentation/usb has
more information.
* The USB 2.0 specification (from www.usb.org), with supplements
such as those for USB OTG and the various device classes.
The USB specification has a good overview chapter, and USB
peripherals conform to the widely known "Chapter 9".
* Chip specifications for USB controllers. Examples include
host controllers (on PCs, servers, and more); peripheral
controllers (in devices with Linux firmware, like printers or
cell phones); and hard-wired peripherals like Ethernet adapters.
* Specifications for other protocols implemented by USB peripheral
functions. Some are vendor-specific; others are vendor-neutral
but just standardized outside of the www.usb.org team.
Here is a list of what each subdirectory here is, and what is contained in
them.
core/ - This is for the core USB host code, including the
usbfs files and the hub class driver ("hub_wq").
host/ - This is for USB host controller drivers. This
includes UHCI, OHCI, EHCI, and others that might
be used with more specialized "embedded" systems.
gadget/ - This is for USB peripheral controller drivers and
the various gadget drivers which talk to them.
Individual USB driver directories. A new driver should be added to the
first subdirectory in the list below that it fits into.
image/ - This is for still image drivers, like scanners or
digital cameras.
../input/ - This is for any driver that uses the input subsystem,
like keyboard, mice, touchscreens, tablets, etc.
../media/ - This is for multimedia drivers, like video cameras,
radios, and any other drivers that talk to the v4l
subsystem.
../net/ - This is for network drivers.
serial/ - This is for USB to serial drivers.
storage/ - This is for USB mass-storage drivers.
class/ - This is for all USB device drivers that do not fit
into any of the above categories, and work for a range
of USB Class specified devices.
misc/ - This is for all USB device drivers that do not fit
into any of the above categories.