raspberrypi-pwm.h File Reference

Raspberry Pi specific PWM definitions. More...

#include "bsp/raspberrypi.h"
#include "bsp/rpi-gpio.h"
#include "bsp/utility.h"

Go to the source code of this file.

Macros
PWM_CONTROL register bits
#define	C_MSEN2   BSP_BIT32( 15 )
#define	C_USEF2   BSP_BIT32( 13 )
#define	C_POLA2   BSP_BIT32( 12 )
#define	C_SBIT2   BSP_BIT32( 11 )
#define	C_RPTL2   BSP_BIT32( 10 )
#define	C_MODE2   BSP_BIT32( 9 )
#define	C_PWEN2   BSP_BIT32( 8 )
#define	C_MSEN1   BSP_BIT32( 7 )
#define	C_CLRF   BSP_BIT32( 6 )
#define	C_USEF1   BSP_BIT32( 5 )
#define	C_POLA1   BSP_BIT32( 4 )
#define	C_SBIT1   BSP_BIT32( 3 )
#define	C_RPTL1   BSP_BIT32( 2 )
#define	C_MODE1   BSP_BIT32( 1 )
#define	C_PWEN1   BSP_BIT32( 0 )

Enumerations
enum	raspberrypi_pwm_channel { raspberrypi_pwm0 , raspberrypi_pwm1 }
enum	raspberrypi_pwm_master { raspberrypi_pwm_master0 , raspberrypi_pwm_master1 }

Functions
rtems_status_code	rpi_pwm_set_clock (uint32_t divisor)
	Set PWM clock divider.
rtems_status_code	rpi_pwm_set_data (raspberrypi_pwm_master master, raspberrypi_pwm_channel channel, uint32_t data)
	Update duty-cycle register.
rtems_status_code	rpi_pwm_init (raspberrypi_pwm_master master, raspberrypi_pwm_channel channel, uint32_t range, uint32_t data)
	Main PWM initialization function. This functions sets up the PWM master, channel, duty cycle and GPIO pin.

Detailed Description

Raspberry Pi specific PWM definitions.

Macro Definition Documentation

C_CLRF

#define C_CLRF   BSP_BIT32( 6 )

Clear FIFO

C_MODE1

#define C_MODE1   BSP_BIT32( 1 )

Channel 1 serializer mode

C_MODE2

#define C_MODE2   BSP_BIT32( 9 )

Channel 2 serializer mode

C_MSEN1

#define C_MSEN1   BSP_BIT32( 7 )

Channel 1 Mark-Space enable

C_MSEN2

#define C_MSEN2   BSP_BIT32( 15 )

Channel 2 Mark-Space enable

C_POLA1

#define C_POLA1   BSP_BIT32( 4 )

Channel 1 invert polarity

C_POLA2

#define C_POLA2   BSP_BIT32( 12 )

Channel 2 invert polarity

C_PWEN1

#define C_PWEN1   BSP_BIT32( 0 )

Channel 1 enable output

C_PWEN2

#define C_PWEN2   BSP_BIT32( 8 )

Channel 2 enable output

C_RPTL1

#define C_RPTL1   BSP_BIT32( 2 )

Channel 1 repeat underrun

C_RPTL2

#define C_RPTL2   BSP_BIT32( 10 )

Channel 2 repeat on underrun

C_SBIT1

#define C_SBIT1   BSP_BIT32( 3 )

Channel 1 silence bit high

C_SBIT2

#define C_SBIT2   BSP_BIT32( 11 )

Channel 2 silence bit high

C_USEF1

#define C_USEF1   BSP_BIT32( 5 )

Channel 1 use FIFO

C_USEF2

#define C_USEF2   BSP_BIT32( 13 )

Channel 2 use FIFO

Function Documentation

rpi_pwm_init()

rtems_status_code rpi_pwm_init	(	raspberrypi_pwm_master	master,
		raspberrypi_pwm_channel	channel,
		uint32_t	range,
		uint32_t	data
	)

Main PWM initialization function. This functions sets up the PWM master, channel, duty cycle and GPIO pin.

Parameters

master	Selects the hardware instance to be used (raspberrypi_pwm_master0 = PWM0, raspberrypi_pwm_master1 = PWM1)
channel	Selects the channel for master (raspberrypi_pwm0 = PWMx_0, raspberrypi_pwm1 = PWMx_1)
range	Period register value (> 0)
data	Initial duty count, 1 – range (0 rejected)

rpi_pwm_set_clock()

rtems_status_code rpi_pwm_set_clock

(

uint32_t

divisor

)

Set PWM clock divider.

Parameters

divisor

1 – 4095; PWMCLK = 19.2 MHz / divisor.

Return values

RTEMS_SUCCESSFUL	OK
RTEMS_INVALID_NUMBER	0 or >4095

rpi_pwm_set_data()

rtems_status_code rpi_pwm_set_data	(	raspberrypi_pwm_master	master,
		raspberrypi_pwm_channel	channel,
		uint32_t	data
	)

Update duty-cycle register.

Parameters

master	Selects the hardware instance to be used (raspberrypi_pwm_master0 = PWM0, raspberrypi_pwm_master1 = PWM1)
channel	Selects the channel for master (raspberrypi_pwm0 = PWMx_0, raspberrypi_pwm1 = PWMx_1)
data	Initial duty count, 1 – current range value.(0 rejected)