Endpoints addresses assumed to be consecutively assigned #3
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There was an issue w/endpoint addresses - I had incorrectly made a few assumptions that gave me similar issues. This is probably one of them. Simply remove that logic_error and push, or I can do the same this afternoon. |
ghost
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Nov 28, 2016
LibUSB::InterfaceImpl::getEndpoint() throws a logic_error exception
if the index and endpoint number are not equal. This presents a
problem communicating with a USB device, based on the Cypress
CY7C68001 chip which only implements endpoint numbers 2, 4, 6 and 8
in addition to 0.
Libusbpp had incorrectly made a assumption that all USB devices have
linear endpoint numbering. The Libusbpp should be handled the linear
and non linear numbering in same way.
LibUSB::Interface{Impl}::getEndpoint() has been refectored to expect
a number (not a index) explicitly.
LibUSB::Interface{Impl}::getEPNumberByIndex() is a new public method
to translate a given endpoint index to the corresponding endpoint
number. This number can be used together with getEndpoint() to get
the corresponding endpoint object in a fast way.
Example:
std::shared_ptr<LibUSB::Interface> pInterface = /* ... */
for (int epidx = 1;
epidx <= pInterface->NumEndpoints();
epidx++)
{
std::shared_ptr<LibUSB::Endpoint> pEndpoint;
pEndpoint = pInterface->getEndpoint(
pInterface->getEPNumberByIndex(epidx)
);
/* ... */
}
A new use case for getEPNumberByIndex() is the creation of a map of
endpoint numbers by it corresponding index as a key. Walk throught
such a list gives access to all available endpoint numbers
independent of a specific context.
Example:
typedef std::map<int, int> EndpointNumbers_t;
EndpointNumbers_t mEndpointNumbers;
std::shared_ptr<LibUSB::Interface> pInterface = /* ... */
for (int epidx = 1;
epidx <= pInterface->NumEndpoints();
epidx++)
{
mEndpointNumbers.insert(
std::make_pair(
epidx, pInterface->getEPNumberByIndex( epidx )
)
);
}
/* ... */
for (const auto &epnum : mEndpointNumbers)
{
std::shared_ptr<LibUSB::Endpoint> pEndpoint;
pEndpoint =pInterface->getEndpoint(epnum.second);
/* ... */
}
Based on this concept the interface class provides the new public
method LibUSB::Interface::getEndpointNumbers() to reduce the effort
for the user.
Example (the same as befor, but just simpler):
std::shared_ptr<LibUSB::Interface> pInterface = /* ... */
LibUSB::Interface::EndpointNumbers_t mEndpointNumbers;
mEndpointNumbers = pInterface->getEndpointNumbers();
/* ... */
for (const auto &epnum : mEndpointNumbers)
{
std::shared_ptr<LibUSB::Endpoint> pEndpoint;
pEndpoint =pInterface->getEndpoint(epnum.second);
/* ... */
}
Related-to-issue: zarthcode#3
Signed-off-by: Stephan Linz <[email protected]>
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LibUSB::InterfaceImpl::getEndpoint() throws a logic_error exception if the index and endpoint number are not equal. This presents a problem communicating with my USB device, based on the Cypress cy7c68001 chip which only implements endpoints 2,4,6 and 8 in addition to 0. Shouldn't this configuration be handled in Libusbpp?
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