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1/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
2
3#ifndef _UAPI_PWM_H_
4#define _UAPI_PWM_H_
5
6#include <linux/ioctl.h>
7#include <linux/types.h>
8
9/**
10 * struct pwmchip_waveform - Describe a PWM waveform for a pwm_chip's PWM channel
11 * @hwpwm: per-chip relative index of the PWM device
12 * @__pad: padding, must be zero
13 * @period_length_ns: duration of the repeating period.
14 * A value of 0 represents a disabled PWM.
15 * @duty_length_ns: duration of the active part in each period
16 * @duty_offset_ns: offset of the rising edge from a period's start
17 */
18struct pwmchip_waveform {
19 __u32 hwpwm;
20 __u32 __pad;
21 __u64 period_length_ns;
22 __u64 duty_length_ns;
23 __u64 duty_offset_ns;
24};
25
26/* Reserves the passed hwpwm for exclusive control. */
27#define PWM_IOCTL_REQUEST _IO(0x75, 1)
28
29/* counter part to PWM_IOCTL_REQUEST */
30#define PWM_IOCTL_FREE _IO(0x75, 2)
31
32/*
33 * Modifies the passed wf according to hardware constraints. All parameters are
34 * rounded down to the next possible value, unless there is no such value, then
35 * values are rounded up. Note that zero isn't considered for rounding down
36 * period_length_ns.
37 */
38#define PWM_IOCTL_ROUNDWF _IOWR(0x75, 3, struct pwmchip_waveform)
39
40/* Get the currently implemented waveform */
41#define PWM_IOCTL_GETWF _IOWR(0x75, 4, struct pwmchip_waveform)
42
43/* Like PWM_IOCTL_ROUNDWF + PWM_IOCTL_SETEXACTWF in one go. */
44#define PWM_IOCTL_SETROUNDEDWF _IOW(0x75, 5, struct pwmchip_waveform)
45
46/*
47 * Program the PWM to emit exactly the passed waveform, subject only to rounding
48 * down each value less than 1 ns. Returns 0 on success, -EDOM if the waveform
49 * cannot be implemented exactly, or other negative error codes.
50 */
51#define PWM_IOCTL_SETEXACTWF _IOW(0x75, 6, struct pwmchip_waveform)
52
53#endif /* _UAPI_PWM_H_ */