clockManager.cpp File Reference

Interface to the clock manager peripheral. More...

#include <memoryManagement/addressing.h>
#include <memoryManagement/physMemoryManagement.h>
#include <CCRCodingUtils/include/errorManagement.h>
#include <peripherals/clockManager.h>
#include <CCRCodingUtils/include/utils.h>
#include <unistd.h>

Macros
#define	CLOCK_MANAGER_BASE_ADDR_PHYS   (peripheralsBaseAddressPhys + 0x101000)
	Physical base address of the clock manager peripheral.
#define	CLOCK_MANAGER_AREA_LEN   0x100
	Length in bytes of the memory area dedicated to the clock manager.
#define	REG_CM_GP0CTL_OFF   (0x70)
	Offset to the general purpose clock 0 control register.
#define	REG_CM_GP1CTL_OFF   (0x78)
	Offset to the general purpose clock 1 control register.
#define	REG_CM_GP2CTL_OFF   (0x80)
	Offset to the general purpose clock 2 control register.
#define	REG_CM_PCMCTL_OFF   (0x98)
	Offset to the PCM clock control register.
#define	REG_CM_PWMCTL_OFF   (0xa0)
	Offset to the PWM clock control register.
#define	REG_CM_GP0DIV_OFF   (0x74)
	Offset to the general purpose clock 0 divisor register.
#define	REG_CM_GP1DIV_OFF   (0x7c)
	Offset to the general purpose clock 1 divisor register.
#define	REG_CM_GP2DIV_OFF   (0x84)
	Offset to the general purpose clock 2 divisor register.
#define	REG_CM_PCMDIV_OFF   (0x9c)
	Offset to the PCM clock divisor register.
#define	REG_CM_PWMDIV_OFF   (0xa4)
	Offset to the PWM clock divisor register.
#define	CM_PASSWORD   (0x5a<<24)
	clock manager password. You must OR this to every write you make to the clock manager registers
#define	CM_CTL_MASH_MASK   (3<<9)
	Control register mask: mash filter level.
#define	CM_CTL_FLIP_MASK   (1<<8)
	Control register mask: Invert the clock output.
#define	CM_CTL_BUSY_MASK   (1<<7)
	Control register mask: Clock generator is running.
#define	CM_CTL_KILL_MASK   (1<<6)
	Control register mask: Kill the clock.
#define	CM_CTL_ENAB_MASK   (1<<4)
	Control register mask: Enable the clock generator.
#define	CM_CTL_SRC_MASK   (0xf)
	Control register mask: Clock source.

Functions
int	clkMan_init ()
	Initializes this peripheral interface, to use before any other function in this file. More...
int	clkMan_isInit ()
	true if clkMan_init has been called with success
int	clkMan_setClock_gp0 (int clockSrc, int divisorInt, int divisorFrac)
	sets the clock for the general purpouse clock 0 More...
int	clkMan_setClock_gp1 (int clockSrc, int divisorInt, int divisorFrac)
	sets the clock for the general purpouse clock 1 More...
int	clkMan_setClock_gp2 (int clockSrc, int divisorInt, int divisorFrac)
	sets the clock for the general purpouse clock 2 More...
int	clkMan_setClock_pcm (int clockSrc, int divisorInt, int divisorFrac)
	sets the clock for the pcm peripheral More...
int	clkMan_setClock_pwm (int clockSrc, int divisorInt, int divisorFrac)
	sets the clock for the pwm peripheral More...

Detailed Description

Interface to the clock manager peripheral.

If you haven't already, see clockManager.h You can find the documentation on the BCM2835 at page 105. The documentation about pwm and pcm clocks is missing in the official doc, there's a pdf by G.J Van Loo with the missing info at https://www.scribd.com/doc/127599939/BCM2835-Audio-clocks

Function Documentation

int clkMan_init

(

)

Initializes this peripheral interface, to use before any other function in this file.

Returns

negative in case of error

int clkMan_setClock_gp0	(	int	clockSrc,
		int	divisorInt,
		int	divisorFrac
	)

sets the clock for the general purpouse clock 0

Parameters

clockSrc	The desired clock source (use the CLK_SRC_* macros)
divisorInt	Integer part of the divisor
divisorFrac	Fractional part of the divisor

Returns

negative in case of error

int clkMan_setClock_gp1	(	int	clockSrc,
		int	divisorInt,
		int	divisorFrac
	)

sets the clock for the general purpouse clock 1

Parameters

clockSrc	The desired clock source (use the CLK_SRC_* macros)
divisorInt	Integer part of the divisor
divisorFrac	Fractional part of the divisor

Returns

negative in case of error

int clkMan_setClock_gp2	(	int	clockSrc,
		int	divisorInt,
		int	divisorFrac
	)

sets the clock for the general purpouse clock 2

Parameters

clockSrc	The desired clock source (use the CLK_SRC_* macros)
divisorInt	Integer part of the divisor
divisorFrac	Fractional part of the divisor

Returns

negative in case of error

int clkMan_setClock_pcm	(	int	clockSrc,
		int	divisorInt,
		int	divisorFrac
	)

sets the clock for the pcm peripheral

Parameters

clockSrc	The desired clock source (use the CLK_SRC_* macros)
divisorInt	Integer part of the divisor
divisorFrac	Fractional part of the divisor

Returns

negative in case of error

int clkMan_setClock_pwm	(	int	clockSrc,
		int	divisorInt,
		int	divisorFrac
	)

sets the clock for the pwm peripheral

Parameters

clockSrc	The desired clock source (use the CLK_SRC_* macros)
divisorInt	Integer part of the divisor
divisorFrac	Fractional part of the divisor

Returns

negative in case of error