LinuxPWM Class Reference

Implementation of a single PWM channel using the linux sysfs API. More...

#include <LinuxPWM.hxx>

Inheritance diagram for LinuxPWM:

Public Member Functions
	LinuxPWM (int chip, int channel)
	Constructor.
void	export_pin ()
	Call this once after instantiating the object but before using any of the PWM apis.
void	set_period (uint32_t counts) override
	Set PWM period.
uint32_t	get_period () override
	Get PWM period.
void	set_duty (uint32_t counts) override
	Sets the duty cycle.
uint32_t	get_duty () override
	Gets the duty cycle.
uint32_t	get_period_max () override
	Get max period supported.
uint32_t	get_period_min () override
	Get min period supported.
void	enable ()
	Enables the output PWM waveform.
void	disable ()
	Disables the output PWM waveform.
bool	enabled ()
	Returns whether the output PWM waveform is enabled or not.
Public Member Functions inherited from PWM
void	set_duty_percent (uint8_t percent)
	Sets the duty cycle.
uint8_t	get_duty_percent ()
	Gets the duty cycle.

Private Member Functions
uint32_t	get_sysfs_file_value (const char *basename)
	Returns a single file's content from the channel directory on sysfs.
void	set_sysfs_file_value (const char *basename, uint32_t value)
	Writes a single integer into a sysfs file of the channel directory.

Private Attributes
const uint32_t	chip_
	Kernel number of the chip.
const uint32_t	channel_
	Number of the channel in the chip.
const string	pwmdir_
	Diretory path of the channel, with trailing /.

Static Private Attributes
static constexpr const char *	ENABLE_FILE = "enable"
	Basename for sysfs file for enabling the channel.
static constexpr const char *	PERIOD_FILE = "period"
	Basename for sysfs file for setting the period.
static constexpr const char *	DUTY_CYCLE_FILE = "duty_cycle"
	Basename for sysfs file for setting the duty cycle.

Additional Inherited Members
Protected Member Functions inherited from PWM
constexpr	PWM ()=default
	Constructor.
	~PWM ()=default
	Destructor.

Detailed Description

Implementation of a single PWM channel using the linux sysfs API.

Definition at line 58 of file LinuxPWM.hxx.

Constructor & Destructor Documentation

LinuxPWM()

LinuxPWM::LinuxPWM ( int  chip, int  channel  )

inline

Constructor.

Parameters

chip	is an integer, the index in the kernel where the PWM chip is registered.
channel	the index of the output channel on the specific chip to use.

Definition at line 66 of file LinuxPWM.hxx.

Member Function Documentation

disable()

void LinuxPWM::disable ( )

inline

Disables the output PWM waveform.

Definition at line 162 of file LinuxPWM.hxx.

enable()

void LinuxPWM::enable ( )

inline

Enables the output PWM waveform.

Definition at line 156 of file LinuxPWM.hxx.

enabled()

bool LinuxPWM::enabled ( )

inline

Returns whether the output PWM waveform is enabled or not.

Definition at line 168 of file LinuxPWM.hxx.

export_pin()

void LinuxPWM::export_pin ( )

inline

Call this once after instantiating the object but before using any of the PWM apis.

Definition at line 76 of file LinuxPWM.hxx.

get_duty()

uint32_t LinuxPWM::get_duty ( )

inlineoverridevirtual

Gets the duty cycle.

Returns

counts duty cycle in counts

Implements PWM.

Definition at line 137 of file LinuxPWM.hxx.

get_period()

uint32_t LinuxPWM::get_period ( )

inlineoverridevirtual

Get PWM period.

Returns

PWM period in counts

Implements PWM.

Definition at line 115 of file LinuxPWM.hxx.

get_period_max()

uint32_t LinuxPWM::get_period_max ( )

inlineoverridevirtual

Get max period supported.

Returns

period in counts

Implements PWM.

Definition at line 144 of file LinuxPWM.hxx.

get_period_min()

uint32_t LinuxPWM::get_period_min ( )

inlineoverridevirtual

Get min period supported.

Returns

period in counts

Implements PWM.

Definition at line 149 of file LinuxPWM.hxx.

get_sysfs_file_value()

uint32_t LinuxPWM::get_sysfs_file_value ( const char *  basename )

inlineprivate

Returns a single file's content from the channel directory on sysfs.

Parameters

basename

is the name of the file (e.g. "period")

Returns

the contents of the file converted to integer.

Definition at line 193 of file LinuxPWM.hxx.

set_duty()

void LinuxPWM::set_duty ( uint32_t  counts )

inlineoverridevirtual

Sets the duty cycle.

Parameters

counts

duty cycle in counts

Implements PWM.

Definition at line 122 of file LinuxPWM.hxx.

set_period()

void LinuxPWM::set_period ( uint32_t  counts )

inlineoverridevirtual

Set PWM period.

Parameters

PWM	period in counts

Implements PWM.

Definition at line 99 of file LinuxPWM.hxx.

set_sysfs_file_value()

void LinuxPWM::set_sysfs_file_value ( const char *  basename, uint32_t  value  )

inlineprivate

Writes a single integer into a sysfs file of the channel directory.

Parameters

basename	is the name of the file (e.g. "period")
value	is the number to write.

Definition at line 214 of file LinuxPWM.hxx.

Member Data Documentation

channel_

const uint32_t LinuxPWM::channel_

private

Number of the channel in the chip.

Definition at line 186 of file LinuxPWM.hxx.

chip_

const uint32_t LinuxPWM::chip_

private

Kernel number of the chip.

Definition at line 184 of file LinuxPWM.hxx.

DUTY_CYCLE_FILE

constexpr const char* LinuxPWM::DUTY_CYCLE_FILE = "duty_cycle"

staticconstexprprivate

Basename for sysfs file for setting the duty cycle.

Definition at line 181 of file LinuxPWM.hxx.

ENABLE_FILE

constexpr const char* LinuxPWM::ENABLE_FILE = "enable"

staticconstexprprivate

Basename for sysfs file for enabling the channel.

Definition at line 177 of file LinuxPWM.hxx.

PERIOD_FILE

constexpr const char* LinuxPWM::PERIOD_FILE = "period"

staticconstexprprivate

Basename for sysfs file for setting the period.

Definition at line 179 of file LinuxPWM.hxx.

pwmdir_

const string LinuxPWM::pwmdir_

private

Diretory path of the channel, with trailing /.

Definition at line 188 of file LinuxPWM.hxx.

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The documentation for this class was generated from the following file:

• LinuxPWM.hxx