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 */ 18 struct 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_ */ 54