6 ioctl commands description, 1 initialization and configuration ioctls, Ioctl commands description – Maxim Integrated 73M1822/73M1922 Control Module User Manual

Page 21: Initialization and configuration ioctls

UG_1x22_053

73M1822/73M1922 Control Module User Guide

Rev. 1.0

6 IOCTL Commands Description

Upon successful opening of a device or channel descriptor the application layer can control the operation
of the device and the modem channel. The application in user space communicates with the driver via
standard Linux driver interface IOCTL calls.

Unless specified, in general, the IOCTL function returns zero (0) for successful request, or a negative
value of EFAULT (-EFAULT) if any error is detected during the processing of the IOCTL. The more detail
cause of error, or also known as error code, is stored internally and can be retrieved with the
M1X22_ERROR_CODE_GET

IOCTL. The driver keeps only the last error code of the last IOCTL per device

or channel descriptor. Therefore, if required, the error code must be retrieved immediately after the
execution of the IOCTL or before the next IOCTL is executed. The error codes are listed in

Section 7.4

The following sections describe the detail of each IOCTL command. The driver IOCTL belongs to one of
the following categories:

• Initialization
• Event and Status Services
• modem Hook Switch Control Services
• Caller-ID Services
• Ring Detection Services
• Line State Analysis Services
• GPIO Services
• Miscellaneous Service

6.1 Initialization and Configuration IOCTLs

The following IOCTLs are defined to configure the 73M1x22. Table 1 provides a summary of the IOCTLs.

Table 1: Summary of Initialization IOCTLs

IOCTL Name

Description

Descriptor

M1X22_CH_INIT

Initializing modem channel for operation.

Channel

M1X22_CNTRY_NMBR_

GET

Convert ASCII two-character country code
into country code index used by the driver.