Add a driver for the DER EE DE-5000 LCR meter. This meter is based on
the Cyrustek ES51919/ES51920 chipset and communicates with the host
computer via an optional connectivity kit.
The kit uses an optoisolated unidirectional link to connect to the
meter and an USB cable on the host side. Internally the connection is
using the FTDI FT232R USB UART chip i.e. from the host computer point
of view the meter is connected into an RS-232 serial port.
This driver implements just a thin shim layer for registering the
driver and uses the es51919 module for all the actual work.
Set this new parameter to 0 (no timeout) at every call site. This is
consistent with previous behaviour, so cannot cause any regressions.
Waiting forever for a serial operation is clearly always wrong. Without
specific knowledge of each device and driver however, I can't choose
appropriate timeouts for each call. The maintainers of these drivers
will need to do so, and also add appropriate handling of timeouts.
When this commit is merged, a bug should be entered for each driver
that is touched by it.
Previously, sdi->index was used to tell several identical fx2lafw-compatible
devices apart. This was a bit of a hack, so this patch makes it use physical
device connections instead. They're guaranteed to remain the same even if
the USB device reconnects.
These calls are executed from an event handler and were previously nonblocking,
but they have no partial read/write handling. The code is already marked TODO
for improvement.
This call is executed from an event handler and was previously nonblocking,
but has no partial write handling. It sends a short packet so should be OK
to block, most likely the output buffer will be empty anyway.
This call was already nonblocking since the driver opens the port with the
SERIAL_NONBLOCK flag. It only reads one byte, and a zero result is handled
appropriately.
This call was previously explicitly nonblocking, but has no partial write
handling. It sends a short packet so should be OK to block, most likely the
output buffer will be empty anyway.
This call was already nonblocking since the driver opens the port with the
SERIAL_NONBLOCK flag. It only reads one byte, and a zero result is handled
appropriately.
This call is executed from an event handler and was previously nonblocking,
but has no partial write handling. It sends a short packet so should be OK
to block, most likely the output buffer will be empty anyway.
These calls are executed from an event handler and were previously nonblocking,
but have no partial write handling. They send short packets so should be OK to
block, most likely the output buffer will be empty anyway.
Fix error handling for some: serial_write can return any negative error code.
This call was previously nonblocking, but there is no handling of partial
writes. It is called from config_set where it is free to block.
Also fix error handling: serial_write can return any negative error code,
not just -1.
These calls were already nonblocking since the driver opens the port with the
SERIAL_NONBLOCK flag. They only read one byte. A return value of zero is not
handled, but should not occur in theory due to the G_IO_IN check. It might be
good to add handling of a zero return anyway, since I'm not sure if this is
always accurate.
This call was already nonblocking since the driver opens the port with the
SERIAL_NONBLOCK flag. It only reads one byte, and a zero result is handled
appropriately.
Bert Vermeulen
Janne Huttunen
Martin Ling
Soeren Apel