diff options
Diffstat (limited to 'include/uapi/linux/pwm.h')
| -rw-r--r-- | include/uapi/linux/pwm.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/include/uapi/linux/pwm.h b/include/uapi/linux/pwm.h new file mode 100644 index 000000000000..182d59cc07ee --- /dev/null +++ b/include/uapi/linux/pwm.h @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ + +#ifndef _UAPI_PWM_H_ +#define _UAPI_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 /* _UAPI_PWM_H_ */ |