Maxim Integrated 73M1822/73M1922 Hardware Module for SMDK412 - Manual (Page 7)

UG_1x22_054 73M1822/73M1922 Hardware Module for SMDK412 User Guide
Rev. 1.1 7
3 Accessing the Driver from the Linux User Space
The driver provides the link between the modem device and the user application via a standard linux
character device. Access to the driver is done via Linux supplied file descriptors The following sections
describe how the driver is brought into action based on the operating system environment.
3.1 mknod
The device descriptors can be created using the mknod command as illustrated below:
mknod -m 660 /dev/tsc_1x22_mafe_0 c 251 0
mknod -m 660 /dev/tsc_1x22_mafe_1 c 251 1
In this example, one descriptor (tsc_1x22_ctl_mafe_0) is created with major number 251, minor
number 0, and one descriptor (tsc_1x22_ctl_mafe_l) is created with major number 251, minor
number 1. The minor number associated with the file descriptor is unused by the driver in this
implementation.
3.2 open
Description
Once the driver is installed and the device descriptors are created, the driver service can be accessed by
user applications via standard C library
open() , and subsequently reversed with close()
Prototype
int open (
const char * path,
int flags);
Parameters
Data Type Name Description
Const char * path Path to the descriptor created by mknod.
int flags O_RDWR.
Return Values
Data Type Description
int File descriptor.