Hi,
Having trouble with UART4. Using Debian stretch image from the downloads section on an sdcard. UART4 or ttyS2 i believe doesn’t seem to be working.
dmesg | grep tty returns
[ 0.000000] Kernel command line: earlyprintk console=ttyfIQ0,1500000n8 rw root=PARTUUID=b921b045-1d rootfstype=ext4 init=/sbin/init rootwait
[ 0.136627] Registered fIQ tty driver
[ 0.218979] console [ttyfIQ0] enabled
[ 0.219484] Registered fiq debugger ttyfIQ0
[ 0.986006] ff180000.serial: ttyS0 at MMIO 0xff180000 (irq = 36, base_baud = 1500000) is a 16550A
[ 0.987405] ff1a0000.serial: ttyS2 at MMIO 0xff1a0000 (irq = 37, base_baud = 1500000) is a 16550A
Looks good to me. But when i run something like this
stty -f /dev/ttyS2 -a
I get
stty: /dev/ttyS2: Input/output error
When I run it for ttyS0
stty -f /dev/ttyS0 -a
I get the info for the port
speed 9600 baud; rows 0; columns 0; line = 0;
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; eol = ; eol2 = ; swtch = ; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0;
-parenb -parodd -cmspar cs8 hupcl -cstopb cread clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff -iuclc -ixany -imaxbel -iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke -flusho -extproc
At a loss as to why it would show up in dmesg but not be available to configure. Any help would be greatly appreciated.
Thanks
Mike