Without the cast non integer frequencies weren't possible (e.g. with a sampling
frequency of 50Hz we would end up with a signal frequency of 2Hz instead of
2.5Hz). The result were signals which had an incorrect number of samples per
period.
BugLink: http://sigrok.org/bugzilla/show_bug.cgi?id=297
This adds sine wave generation capabilities for the analog channels in the demo
driver. The frequency of the sine wave depends on the configured sample rate of
the demo device. The frequency of the sine wave is always 20 times smaller than
the sample rate, in other words we always have 20 samples per period.
The per-driver API calls no longer have a hw_ prefix (e.g. hw_init()
became init() and so on), so drop the 'hw_' from the std versions
for those API callbacks too.
This is a small helper function which sends the SR_DF_HEADER packet that
drivers usually emit in their hw_dev_acquisition_start() API callback.
It simplifies and shortens the hw_dev_acquisition_start() functions
quite a bit.
It also simplifies the input modules which send an SR_DF_HEADER packet, too.
This patch also automatically removes some unneeded malloc/free in some
drivers for the 'packet' and 'header' structs used for SR_DF_HEADER.
Check the relevant arguments for != NULL before calling the actual
driver-specific function, so that the driver can safely assume those
arguments are non-NULL. This removes the need to duplicate these
checks in every driver.
Also, do some minor whitespace and consistency improvements.
Check the relevant arguments for != NULL before calling the actual
driver-specific function, so that the driver can safely assume those
arguments are non-NULL. This removes the need to duplicate these
checks in every driver.
Also, change one SR_ERR to the more correct SR_ERR_MALLOC, and assign
sr_ctx in the rigol-ds1xx2's hw_init() function, like all the other
drivers do.
Sending an SR_DF_META packet at the start of every stream is not
mandatory; the frontend should ask for what it needs, and any extra
information the driver wants to send will come in due time.