For some boards, the linemode (E1/T1/J1) is software selectable but
needs to be configured before the spans were historically registered
since the line mode determines the channel count available on the span.
This change exports a "spantype" attribute from the dahdi_device that
can be used to set E1/T1/J1 before the spans are assigned. When
userspace writes to this attribute (in a <span offset>:<span type
string> format), and if the board driver has implemented a set_spantype
function in it's dahdi_span_ops, then the board driver can optionally
change it's mode before registration.
Also part of this change is breaking out the raw data structure
initialization of the spans / channels via the dahdi_init_device_spans
function since the board drivers may need to reallocate channels / spans
as part of this callback. For example, changing from T1 to E1 mode will
require allocating 7 new channels.
Signed-off-by: Shaun Ruffell <sruffell@digium.com>
git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/trunk@10277 a0bf4364-ded3-4de4-8d8a-66a801d63aff
f9c52bb271