1  \# Author Andy Pugh
 2  \# Issued under the terms of the GPL v2 License or any later version
 3  
 4  .TH hm2_bspi_set_write_function "3hm2" "2011-05-31" "LinuxCNC Documentation" "Hostmot2"
 5  .SH NAME
 6  
 7  hm2_bspi_set_write_function \- Register a function to handle the tram write phase
 8  of a hostmot2 buffered SPI driver. 
 9  .SH SYNTAX
10  .nf
11  .B #include <hostmot2-serial.h>
12  .HP
13  int hm2_bspi_set_write_function(char *name, void *func, void *subdata)
14  
15  .SH DESCRIPTION
16  \fBhm2_bspi_set_write_function\fR registers a function in an external driver
17  to be called every time that the main Hostmot2
18  driver calls the generic "prepare_tram_write" functions. 
19  The names of the available channels are printed with rtapi_print_msg during the
20  driver loading process and take the form:
21  .RS
22  hm2_<board name>.<board index>.bspi.<index>
23  .RE
24  For example hm2_5i23.0.bspi.0.
25  
26  "func" should be a pointer to a function in the sub driver which is to be
27  called to process the pins into BSPI write registers prior to the regular TRAM
28  write phase. The function must take a single argument, a pointer to an
29  individual instance of the internal driver. If defined in comp then the 
30  function must \fBnot\fP use the FUNCTION() convenience macro, and the argument
31  to the function in the definition  must \fBalways\fP be (struct state *inst).
32  
33  "subdata" is a pointer to the driver instance internal data. In the case of a
34  driver written in comp this will always be "inst" in the function call.
35  
36  If using comp then the call to this function should be anywhere in the
37  EXTRA_SETUP code. 
38  
39  .SH REALTIME CONSIDERATIONS
40  Call only from realtime init code, not from user space or realtime code.
41  
42  .SH RETURN VALUE
43  Returns 0 on success and \-1 on failure.
44  
45  .SH SEE ALSO
46  \fBhm2_allocate_bspi_tram(3hm2)\fR,
47  \fBhm2_bspi_set_read_function(3hm2)\fR,
48  \fBhm2_bspi_setup_chan(3hm2)\fR,
49  \fBhm2_bspi_write_chan(3hm2)\fR,
50  \fBhm2_tram_add_bspi_frame(3hm2)\fR,
51  src/hal/drivers mesa_7i65.comp in the LinuxCNC source distribution.