linux-toradex.git/drivers/usb/host/isp1760-hcd.h, branch v3.4.89

usb/isp1760: Allow to optionally trigger low-level chip reset via GPIOLIB.

2011-10-19T20:29:06+00:00

Properly triggering the reset wire is necessary with the ISP1761 used
on Terasic DE4 Altera-FPGA boards using a NIOS2 processor, for example.

This is an optional implementation for the OF binding only. The other
bindings just pass an invalid GPIO to the isp1760_register() routine.

Example, usage in DTS:
        gpios = <&pio_isp1761rst_0 0 1>;
to point to a GPIO controller from within the ISP1761 node: GPIO 0, active low.

Signed-off-by: Joachim Foerster 
Signed-off-by: Greg Kroah-Hartman

usb/isp1760: Use polling instead of SOF interrupts to fix Errata 2

2011-08-22T22:32:45+00:00

Errata 2 for the isp1760 explains that the chip sometimes does not issue
interrupts when an ATL (bulk or control) transfer is completed. There are
several issues with the current work-around (SOF interrupts) for this:

1) It seems the chip sometimes does not even set the done bit for a
   completed transfer, in which case SOF interrupts does not solve
   the problem since we still check the done map to find out which
   transfer descriptors to handle.

2) The above point seems to happen only when ATL and SOF interrupts
   are enabled at the same time. However, disabling ATL interrupts
   increases the latency between transfer completion and handling.
   This is very noticeable in the testusb suite, which take several
   minutes more to run with ATL interrupts disabled.

This patch removes the code to switch on SOF interrupts, and instead
use a kernel timer to periodically check for "old" descriptors that
have their VALID and ACTIVE flags unset, indicating completion, thus
avoiding the dependency on the chip's done map (and SOF interrupts)
to find transfers affected by this HW bug.

[bigeasy@linutronix: 80 lines limit]

Signed-off-by: Arvid Brodin 
Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Greg Kroah-Hartman

usb/isp1760: Improve urb queueing, get rid of BUG():s in normal code paths

2011-05-03T00:03:50+00:00

This patch replaces the code that handles qtds. Intead of directly allocating
chip mem and chip slot, enqueue the transfer in a list of queue heads. Use
a centralized function enqueue_qtds() to prioritize and enqueue transfers.

This removes all of the interrupt context BUG() calls when out of chip
mem or transfer slots. It also makes it possible to efficiently use the
dual-port mem on the chip for double-buffered transfers, which improve
transfer times to/from/between usb sticks by about 40 % on my HW.

With this patch it should also be possible to handle qtd scheduling outside
of the interrupt handler, for significantly improved kernel latency. I have
not implemented this since there are some locking issues which I haven't
had time to look at.

Signed-off-by: Arvid Brodin 
Signed-off-by: Greg Kroah-Hartman

usb/isp1760: Remove unneeded OR map and HcBufferStatus code

2011-05-03T00:02:55+00:00

Since we always set the OR flag for each transfer, we can just as well set all
these bits to 1 at init and be done with it. Also, HcBufferStatus can be set
at init as per the ISP1761 datasheet page 47 with no loss of performance.

Signed-off-by: Arvid Brodin 
Signed-off-by: Greg Kroah-Hartman

usb/isp1760: Consolidate printouts and remove unused code

2011-03-01T03:23:38+00:00

Consolidate printouts to use dev_XXX functions instead of an assortment of
printks and driver specific macros. Remove some unused code snippets and struct
members. Remove some unused function parameters and #defines. Change the
"queue_entry" variable name which has different but related meanings in
different places and use "slot" only.

Signed-off-by: Arvid Brodin 
Signed-off-by: Greg Kroah-Hartman

usb/isp1760: Remove redundant "data_buffer" member from struct inter_packet_info

2011-03-01T03:23:37+00:00

Signed-off-by: Arvid Brodin 
Signed-off-by: Greg Kroah-Hartman

usb/isp1760: Clean up payload address handling

2011-03-01T03:23:37+00:00

Encapsulate payload addresses within qtds.

Signed-off-by: Arvid Brodin 
Signed-off-by: Greg Kroah-Hartman

usb/isp1760: Remove redundant variables and defines

2011-03-01T03:23:36+00:00

Removes the redundant hw_next list pointer from struct isp1760_qtd, removes some
unused #defines, removes redundant "urb" member from struct inter_packet_info.

Signed-off-by: Arvid Brodin 
Signed-off-by: Greg Kroah-Hartman

usb/isp1760: Move to native-endian ptds

2011-03-01T03:23:36+00:00

This helps users with platform-bus-connected isp176xs, big-endian cpu,
and missing byteswapping on the data bus. It does so by collecting all
SW byteswaps in one place and also fixes a bug with non-32-bit io
transfers on this hardware, where payload has to be byteswapped
instead of ptds.

Signed-off-by: Arvid Brodin 
Signed-off-by: Greg Kroah-Hartman

USB: isp1760: Implement solution for erratum 2

2011-02-17T18:47:55+00:00

The document says:
|2.1 Problem description
|    When at least two USB devices are simultaneously running, it is observed that
|    sometimes the INT corresponding to one of the USB devices stops occurring. This may
|    be observed sometimes with USB-to-serial or USB-to-network devices.
|    The problem is not noticed when only USB mass storage devices are running.
|2.2 Implication
|    This issue is because of the clearing of the respective Done Map bit on reading the ATL
|    PTD Done Map register when an INT is generated by another PTD completion, but is not
|    found set on that read access. In this situation, the respective Done Map bit will remain
|    reset and no further INT will be asserted so the data transfer corresponding to that USB
|    device will stop.
|2.3 Workaround
|    An SOF INT can be used instead of an ATL INT with polling on Done bits. A time-out can
|    be implemented and if a certain Done bit is never set, verification of the PTD completion
|    can be done by reading PTD contents (valid bit).
|    This is a proven workaround implemented in software.

Russell King run into this with an USB-to-serial converter. This patch
implements his suggestion to enable the high frequent SOF interrupt only
at the time we have ATL packages queued. It goes even one step further
and enables the SOF interrupt only if we have more than one ATL packet
queued at the same time.

Cc:  # [2.6.35.x, 2.6.36.x, 2.6.37.x]
Tested-by: Russell King 
Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Greg Kroah-Hartman