zig/lib/libc/include/any-linux-any/linux/pwm.h
2025-09-29 22:53:06 +02:00

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1.7 KiB
C
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/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
#ifndef _PWM_H_
#define _PWM_H_
#include <linux/ioctl.h>
#include <linux/types.h>
/**
* struct pwmchip_waveform - Describe a PWM waveform for a pwm_chip's PWM channel
* @hwpwm: per-chip relative index of the PWM device
* @__pad: padding, must be zero
* @period_length_ns: duration of the repeating period.
* A value of 0 represents a disabled PWM.
* @duty_length_ns: duration of the active part in each period
* @duty_offset_ns: offset of the rising edge from a period's start
*/
struct pwmchip_waveform {
__u32 hwpwm;
__u32 __pad;
__u64 period_length_ns;
__u64 duty_length_ns;
__u64 duty_offset_ns;
};
/* Reserves the passed hwpwm for exclusive control. */
#define PWM_IOCTL_REQUEST _IO(0x75, 1)
/* counter part to PWM_IOCTL_REQUEST */
#define PWM_IOCTL_FREE _IO(0x75, 2)
/*
* Modifies the passed wf according to hardware constraints. All parameters are
* rounded down to the next possible value, unless there is no such value, then
* values are rounded up. Note that zero isn't considered for rounding down
* period_length_ns.
*/
#define PWM_IOCTL_ROUNDWF _IOWR(0x75, 3, struct pwmchip_waveform)
/* Get the currently implemented waveform */
#define PWM_IOCTL_GETWF _IOWR(0x75, 4, struct pwmchip_waveform)
/* Like PWM_IOCTL_ROUNDWF + PWM_IOCTL_SETEXACTWF in one go. */
#define PWM_IOCTL_SETROUNDEDWF _IOW(0x75, 5, struct pwmchip_waveform)
/*
* Program the PWM to emit exactly the passed waveform, subject only to rounding
* down each value less than 1 ns. Returns 0 on success, -EDOM if the waveform
* cannot be implemented exactly, or other negative error codes.
*/
#define PWM_IOCTL_SETEXACTWF _IOW(0x75, 6, struct pwmchip_waveform)
#endif /* _PWM_H_ */