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<DIV><SPAN class=509023108-19062012><FONT size=2
face=Arial>Hello,</FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2
face=Arial></FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2 face=Arial>I have a project,
where I have to write a driver for /dev/spidev0.0, but I have problems with
fpioctl.</FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2
face=Arial></FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2 face=Arial>I believe that I
have problems with the parameter passing or type casting of
fpioctl.</FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2 face="Courier New">In some
forums, I've found mysterios Pointer(PtrInt(xx) syntax like that:
fpioctl(fd,funcnum, Pointer(PtrInt(xy)) : </FONT>
<PRE style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px"></SPAN><SPAN class=509023108-19062012><FONT size=2>I have no idea why this construction is necesary</FONT></SPAN>
</PRE><PRE style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px"><SPAN class=509023108-19062012><FONT size=2></FONT></SPAN>
</PRE><PRE style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px"><SPAN class=509023108-19062012><FONT size=2></FONT></SPAN>
</PRE></DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2 face=Arial>My code snipet is
below:</FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2
face=Arial></FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2 face=Arial>spi_ioc_transfer_t =
record<BR>
tx_buf_ptr :
pointer;<BR>
rx_buf_ptr :
pointer;<BR>
len :
longword;<BR>
delay_usec :
word;<BR>
speed_hz :
longword;<BR>
bits_per_word : byte;<BR>
cs_change : byte;<BR>
pad :
longword;<BR>
end;</FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2
face=Arial></FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2 face=Arial>var xfer :
array[0..1] of spi_ioc_transfer_t; rx0,tx0 : array[0..42] of byte;
</FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2
face=Arial></FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2 face=Arial>tx0 [ 0]:=$00; tx0 [
1]:=$00; </FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2 face=Arial>xfer[0].len:=2;
xfer[0].speed_hz:=500000; xfer[0].bits_per_word:=8;<BR>
xfer[0].tx_buf_ptr :=
addr(tx0[ 0]); xfer[0].rx_buf_ptr := addr(rx0[ 0]);</FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2
face=Arial></FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2
face=Arial>fd:=fpOpen('/dev/spidev0.0',O_RdWr);</FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2
face=Arial>...</FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2 face=Arial>result :=
fpioctl(fd, (*SPI_IOC_MESSAGE(1)*) 1075866368, @xfer[0]);</FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2 face=Arial>(* function number
107.. 368 taken from operating c example </FONT></SPAN><SPAN
class=509023108-19062012><FONT size=2 face=Arial>*)</FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2
face=Arial></FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2 face=Arial>I get -1
as result</FONT></SPAN>
</DIV>
<DIV><SPAN class=509023108-19062012><FONT size=2 face=Arial>What's
wrong.</FONT></SPAN>
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