Clean up the mcs7715 port setup by using the new endpoint-remap
functionality provided by core. Instead of poking around in internal
port-structure fields, simply swap the endpoint descriptors of the two
ports in calc_num_ports before the port structures are even allocated.

Note that we still need to override the default interrupt completion
handler.
Signed-off-by: Johan Hovold <johan@kernel.org>

Drop the redundant read-urb check from open. The presence of a bulk-in
endpoint is now verified during probe and core has allocated the
corresponding resources.
Signed-off-by: Johan Hovold <johan@kernel.org>

Verify that the required interrupt endpoint is present at probe rather
than at open to avoid allocating resources for an unusable device.

Note that the endpoint is only required when in download mode.
Signed-off-by: Johan Hovold <johan@kernel.org>

These devices always require at least one bulk-out endpoint so let core
verify that.

This avoids attempting to send bulk data to the default pipe when
downloading firmware in boot mode.

Note that further endpoints are still needed when not in boot mode.
Signed-off-by: Johan Hovold <johan@kernel.org>

Use the calc_num_ports rather than attach callback to verify that the
required endpoints are present when in download mode.

This avoids allocating port resources for interfaces that won't be bound.
Signed-off-by: Johan Hovold <johan@kernel.org>

Use the calc_num_ports callback to ignore unused endpoints.

The driver binds to any interface with at least one bulk-in and one
bulk-out endpoint, but some devices can have three or more endpoints of
which only either the first or second pair of endpoints is needed.

This avoids allocating resources for unused endpoints, and specifically
a port is no longer registered for the unused first endpoint pair when
there are more than three endpoints.
Signed-off-by: Johan Hovold <johan@kernel.org>

Use the calc_num_ports rather than attach callback to determine which
interface to bind to in order to avoid allocating port-resources for
interfaces that won't be bound.
Signed-off-by: Johan Hovold <johan@kernel.org>

We can now abort probe early after an error in calc_num_ports by
returning an errno instead of attempting to continue probing but not
register any ports.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present and moving the max-packet check to
calc_num_ports.
Signed-off-by: Johan Hovold <johan@kernel.org>

Use the calc_num_ports rather than probe callback to determine which
interface to bind to.

This allows us to remove some duplicate code.
Signed-off-by: Johan Hovold <johan@kernel.org>

Implement the "horrible endpoint hack" for some legacy devices as a
quirk and clean up the code somewhat.

Note that the bulk-endpoint check can be removed as core will already
have verified this.
Signed-off-by: Johan Hovold <johan@kernel.org>

Some pl2303 devices require the use of the interrupt endpoint of an
unrelated interface. This has so far been dealt with in usb-serial core,
but can now be moved to a driver calc_num_ports callback.

Note that we relax the endpoint requirements checked by core and instead
verify that we have an interrupt-in endpoint in calc_num_ports for all
devices so that the hack can first be applied.
Signed-off-by: Johan Hovold <johan@kernel.org>

Relax the generic driver bulk-endpoint requirement. The driver handles
devices without bulk-out endpoints just fine these days.
Signed-off-by: Johan Hovold <johan@kernel.org>

Add a calc_num_ports callback to the generic driver and verify that the
device has the required endpoints there instead of in core.

Note that the generic driver num_ports field was never used.
Signed-off-by: Johan Hovold <johan@kernel.org>

Add a probe callback to the generic driver and print the
only-for-testing message there.

This is a first step in getting rid of the CONFIG_USB_SERIAL_GENERIC
ifdef from usb-serial core.
Signed-off-by: Johan Hovold <johan@kernel.org>

Allow subdrivers to modify the port-endpoint mapping by passing the
endpoint descriptors to calc_num_ports.

The callback can now also be used to verify that the required endpoints
exists and abort probing otherwise.

This will allow us to get rid of a few hacks in subdrivers that are
already modifying the port-endpoint mapping (or aborting probe due to
missing endpoints), but only after the port structures have been setup.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.

Note that the driver registers four ports but uses five bulk-endpoint
pairs.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.

Note that the driver uses the second bulk-out endpoint for writing.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.

Note that the driver expects two bulk-endpoint pairs also for mcs7715
devices for which only one serial port is registered.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.

Also require the presence of a bulk-out endpoint, something which
prevents the driver from trying to send bulk messages over the control
pipe should a bulk-out endpoint be missing.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.

Note that this driver uses an additional bulk-endpoint pair as an
out-of-band port.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.
Signed-off-by: Johan Hovold <johan@kernel.org>

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.
Signed-off-by: Johan Hovold <johan@kernel.org>

Allow drivers to specify a minimum number of endpoints per type, which
USB serial core will verify after subdriver probe has returned (where
the current alternate setting may have been changed).
Signed-off-by: Johan Hovold <johan@kernel.org>

Since commit 0a8fd134 ("USB: fix problems with duplicate endpoint
addresses") USB core guarantees that there are no more than 15 endpoint
descriptors per type (and altsetting) so the corresponding overflow
checks can now be replaced with a compile-time check on the array sizes
(and indirectly the maximum number of ports).
Signed-off-by: Johan Hovold <johan@kernel.org>

Raise the arbitrary limit of how many ports a single device can claim
from eight to 16.

This specifically enables the upper eight ports of some mxuport devices.
Signed-off-by: Johan Hovold <johan@kernel.org>

Refactor and clean up endpoint handling.

This specifically moves the endpoint-descriptor arrays of the stack.

Note that an err_free_epds label is not yet added to avoid a compilation
warning when neither CONFIG_USB_SERIAL_PL2303 or
CONFIG_USB_SERIAL_GENERIC is selected.
Signed-off-by: Johan Hovold <johan@kernel.org>

Use unsigned-char type for the endpoint and port counters.
Signed-off-by: Johan Hovold <johan@kernel.org>

Clean up the probe error paths by adding a couple of new error labels.
Signed-off-by: Johan Hovold <johan@kernel.org>

The 'store' function for the "event_char" device attribute currently
expects a base 10 value.  The value is composed of an enable bit in bit
8 and an 8-bit "event character" code in bits 7 to 0.  It seems
reasonable to allow hexadecimal and octal numbers to be written to the
device attribute in addition to decimal.  Make it so.

Change the debug message to show the value in hexadecimal, rather than
decimal.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Johan Hovold <johan@kernel.org>

The "event_char" device attribute value, when written, is interpreted as
an enable bit in bit 8, and an "event character" in bits 7 to 0.

Return an error -EINVAL for out-of-range values.  Use kstrtouint() to
parse the integer instead of the obsolete simple_strtoul().
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Johan Hovold <johan@kernel.org>

Valid latency timer values are between 1 ms and 255 ms in 1 ms steps.
The store function for the "latency_timer" device attribute currently
allows any value, although only the lower 16 bits will be sent to the
device, and the device only stores the lower 8 bits.  The hardware
appears to accept the (invalid) value 0 and treats it the same as 1
(resulting in a latency of 1 ms).

Change the latency_timer_store() function to accept only the values 0 to
255, returning an error -EINVAL for out-of-range values.  Call
kstrtou8() to parse the integer instead of the obsolete
simple_strtoul().
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Johan Hovold <johan@kernel.org>