This README file is best viewed online.

Run the make command from within the source code directory to build the driver.

cd synccom-linux/
make

If you would like to enable debug prints within the driver you need to add the DEBUG option while building the driver.

make DEBUG=1

Once debugging is enabled you will find extra kernel prints in the /var/log/messages and /var/log/debug log files.

If the kernel header files you would like to build against are not in the default location /lib/modules/$(shell uname -r)/build then you can specify the location with the KDIR option while building the driver.

make KDIR="/location/to/kernel_headers/"

Assuming the driver has been successfully built in the previous step you are now ready to load the driver so you can begin using it. To do this you insert the driver's kernel object file (synccom.ko) into the kernel.

cd synccom-linux/
insmod synccom.ko

You will more than likely need administrator privileges for this and the following commands.

All driver load time options can be set in your modprobe.conf file for using upon system boot

If you would like the driver to automatically load at boot use the included installer.

cd synccom-linux/
make install

This will also install the header (.h) files.

To uninstall, use the included uninstaller.

cd synccom-linux/
make uninstall

There is documentation for each specific function listed below, but lets get started with a quick programming example for fun.

This tutorial has already been set up for you at synccom-linux/examples/tutorial.c.

Create a new C file (named tutorial.c) with the following code.

#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    int fd = 0;
    char odata[] = "Hello world!";
    char idata[20];

    /* Open port 0 */
    fd = open("/dev/synccom0", O_RDWR);

    if (fd == -1) {
        perror("open");
        return EXIT_FAILURE;
    }

    /* Send "Hello world!" text */
    write(fd, odata, sizeof(odata));

    /* Read the data back in (with our loopback connector) */
    read(fd, idata, sizeof(idata));

    fprintf(stdout, "%s\n", idata);

    close(fd);

    return EXIT_SUCCESS;
}

For this example I will use the gcc compiler, but you can use your compiler of choice.

# gcc -I ..\lib\raw\ tutorial.c

Now attach the included loopback connector.

# ./a.out
Hello world!

You have now transmitted and received an HDLC frame!

There are likely other configuration options you will need to set up for your own program. All of these options are described on their respective documentation page.

• Connect
• Append Status
• Clock Frequency
• Memory Cap
• Purge
• Read
• Registers
• RX Multiple
• TX Modifiers
• Write
• Disconnect

There are a couple of possibilities but you should first check /var/log/messages for any helpful information. If that doesn't help you out then continue reading.

One possibility is that there is another driver loaded that has claimed our cards. For example if your kernel is patched to use our card for asynchronous transmission the linux serial driver has more than likely claimed the card and in turn we won't receive the appropriate 'probe' notifications to load our card.

Another possibility is that you have accidentally tried insmod'ing with the 'hot_plug' option enabled and your cards are not actually present. Double check that your card shows up in the output of 'lspci' and make sure to use hot_plug=0.

Whether or not you can read data will be based on if there is at least 1 byte of data available to be read in your current mode of operation. For example, if there is streaming data it will not be considered when in a frame based mode.

Whether or not you can write data will be based on if you have hit your output memory cap.

When executing a purge on either the transmitter or receiver there is a TRES or RRES (command from the CMDR register) happening behind the scenes. If there is no clock available the command will stall until a clock is available. This should work in theory but doesn't in practice. So whenever you need to execute a purge without a clock, first put it into clock mode 7, execute your purge then return to your other clock mode.

• Kernel Build Tools (GCC, make, kernel headers, etc)

• OS: Linux
• Base Installation: >= 2.6.16 (might work with a lower version)
• Sysfs Support: >= 2.6.25

We follow Semantic Versioning when creating releases.

Copyright (C) 2016 Commtech, Inc.

Licensed under the GNU General Public License v3.