Telecom Clock—MPCBL0010 SBC

12.4.15Read the Current Reference Clock

To determine the current reference clock used by the telecom clock, use the following:

Function:

IOCTL_READ_CURRENT_REF

Table 137. Reference Clock Values

Current Reference Clock

Value

 

 

Primary Clock

0

 

 

Secondary Clock

q

 

 

12.4.16sysfs Interface

When the Telecom Clock driver is loaded, it creates a sysfs directory under /sys/ devices/platform/telco_clock.

This directory exports the following interfaces as shown in Table 138 where they are mapped to Telecom Clock API functions. (See Section 12.4, “Telecom Clock API” for information about using the Telecom Clock API.)

Table 138. Telecom Clock API Function Mapping for the sysfs Interface

sysfs Interface Name (File Name)

Telecom Clock API Function Name

 

 

alarms

IOCTL_READ_ALARMS

 

 

current_ref

IOCTL_READ_CURRENT_REF

 

 

received_ref_clk3a

IOCTL_SELECT_RECEIVED_REF_CLK3A

 

 

received_ref_clk3b

IOCTL_SELECT_RECEIVED_REF_CLK3B

 

 

enable_clk3a_output

IOCTL_ENABLE_CLK3A_OUTPUT

 

 

enable_clk3b_output

IOCTL_ENABLE_CLK3B_OUTPUT

 

 

enable_clka0_output

IOCTL_ENABLE_CLKA0_OUTPUT

 

 

enable_clka1_output

IOCTL_ENABLE_CLKA1_OUTPUT

 

 

enable_clkb0_output

IOCTL_ENABLE_CLKB0_OUTPUT

 

 

enable_clkb1_output

IOCTL_ENABLE_CLKB1_OUTPUT

 

 

filter_select

IOCTL_FILTER_SELECT

 

 

hardware_switching

IOCTL_HARDWARE_SWITCHING

 

 

hardware_switching_mode

IOCTL_HARDWARE_SWITCHING_MODE

 

 

telclock_version

-

 

 

mode_select

IOCTL_MODE_SELECT

 

 

refalign

IOCTL_REFALIGN

 

 

reset

IOCTL_RESET

 

 

select_amcb1_transmit_clock

IOCTL_SELECT_AMCB1_TRANSMIT_CLOCK

 

 

select_amcb2_transmit_clock

IOCTL_SELECT_AMCB2_TRANSMIT_CLOCK

 

 

select_redundant_clock

IOCTL_SELECT_REDUNDANT_CLOCK

 

 

select_ref_frequency

IOCTL_SELECT_REF_FREQUENCY

 

 

Note: All sysfs interfaces are integers in hex format, i.e., echo 99 > refalign has the same effect as echo 0x99

 

Intel NetStructure® MPCBL0010 Single Board Computer

October 2006

Technical Product Specification

Order Number: 304120

169

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Intel MPCBL0010 Read the Current Reference Clock, Sysfs Interface, Reference Clock Values, Current Reference Clock Value