diff options
author | Jiri Kosina <jkosina@suse.com> | 2025-03-26 13:42:07 +0100 |
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committer | Jiri Kosina <jkosina@suse.com> | 2025-03-26 13:42:07 +0100 |
commit | b3cc7428a32202936904b5b07cf9f135025bafd6 (patch) | |
tree | d4a1a6180ac5939fccd92acd6f8d7d1388575c4a /samples/rust/rust_misc_device.rs | |
parent | db52926fb0be40e1d588a346df73f5ea3a34a4c6 (diff) | |
parent | 01601fdd40ecf4467c8ae4d215dbb7d2a0599a2c (diff) |
Merge branch 'for-6.15/amd_sfh' into for-linus
From: Mario Limonciello <mario.limonciello@amd.com>
Some platforms include a human presence detection (HPD) sensor. When
enabled and a user is detected a wake event will be emitted from the
sensor fusion hub that software can react to.
Example use cases are "wake from suspend on approach" or to "lock
when leaving".
This is currently enabled by default on supported systems, but users
can't control it. This essentially means that wake on approach is
enabled which is a really surprising behavior to users that don't
expect it.
Instead of defaulting to enabled add a sysfs knob that users can
use to enable the feature if desirable and set it to disabled by
default.
Diffstat (limited to 'samples/rust/rust_misc_device.rs')
-rw-r--r-- | samples/rust/rust_misc_device.rs | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/samples/rust/rust_misc_device.rs b/samples/rust/rust_misc_device.rs new file mode 100644 index 0000000000000..40ad7266c2252 --- /dev/null +++ b/samples/rust/rust_misc_device.rs @@ -0,0 +1,238 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2024 Google LLC. + +//! Rust misc device sample. + +/// Below is an example userspace C program that exercises this sample's functionality. +/// +/// ```c +/// #include <stdio.h> +/// #include <stdlib.h> +/// #include <errno.h> +/// #include <fcntl.h> +/// #include <unistd.h> +/// #include <sys/ioctl.h> +/// +/// #define RUST_MISC_DEV_FAIL _IO('|', 0) +/// #define RUST_MISC_DEV_HELLO _IO('|', 0x80) +/// #define RUST_MISC_DEV_GET_VALUE _IOR('|', 0x81, int) +/// #define RUST_MISC_DEV_SET_VALUE _IOW('|', 0x82, int) +/// +/// int main() { +/// int value, new_value; +/// int fd, ret; +/// +/// // Open the device file +/// printf("Opening /dev/rust-misc-device for reading and writing\n"); +/// fd = open("/dev/rust-misc-device", O_RDWR); +/// if (fd < 0) { +/// perror("open"); +/// return errno; +/// } +/// +/// // Make call into driver to say "hello" +/// printf("Calling Hello\n"); +/// ret = ioctl(fd, RUST_MISC_DEV_HELLO, NULL); +/// if (ret < 0) { +/// perror("ioctl: Failed to call into Hello"); +/// close(fd); +/// return errno; +/// } +/// +/// // Get initial value +/// printf("Fetching initial value\n"); +/// ret = ioctl(fd, RUST_MISC_DEV_GET_VALUE, &value); +/// if (ret < 0) { +/// perror("ioctl: Failed to fetch the initial value"); +/// close(fd); +/// return errno; +/// } +/// +/// value++; +/// +/// // Set value to something different +/// printf("Submitting new value (%d)\n", value); +/// ret = ioctl(fd, RUST_MISC_DEV_SET_VALUE, &value); +/// if (ret < 0) { +/// perror("ioctl: Failed to submit new value"); +/// close(fd); +/// return errno; +/// } +/// +/// // Ensure new value was applied +/// printf("Fetching new value\n"); +/// ret = ioctl(fd, RUST_MISC_DEV_GET_VALUE, &new_value); +/// if (ret < 0) { +/// perror("ioctl: Failed to fetch the new value"); +/// close(fd); +/// return errno; +/// } +/// +/// if (value != new_value) { +/// printf("Failed: Committed and retrieved values are different (%d - %d)\n", value, new_value); +/// close(fd); +/// return -1; +/// } +/// +/// // Call the unsuccessful ioctl +/// printf("Attempting to call in to an non-existent IOCTL\n"); +/// ret = ioctl(fd, RUST_MISC_DEV_FAIL, NULL); +/// if (ret < 0) { +/// perror("ioctl: Succeeded to fail - this was expected"); +/// } else { +/// printf("ioctl: Failed to fail\n"); +/// close(fd); +/// return -1; +/// } +/// +/// // Close the device file +/// printf("Closing /dev/rust-misc-device\n"); +/// close(fd); +/// +/// printf("Success\n"); +/// return 0; +/// } +/// ``` +use core::pin::Pin; + +use kernel::{ + c_str, + device::Device, + fs::File, + ioctl::{_IO, _IOC_SIZE, _IOR, _IOW}, + miscdevice::{MiscDevice, MiscDeviceOptions, MiscDeviceRegistration}, + new_mutex, + prelude::*, + sync::Mutex, + types::ARef, + uaccess::{UserSlice, UserSliceReader, UserSliceWriter}, +}; + +const RUST_MISC_DEV_HELLO: u32 = _IO('|' as u32, 0x80); +const RUST_MISC_DEV_GET_VALUE: u32 = _IOR::<i32>('|' as u32, 0x81); +const RUST_MISC_DEV_SET_VALUE: u32 = _IOW::<i32>('|' as u32, 0x82); + +module! { + type: RustMiscDeviceModule, + name: "rust_misc_device", + author: "Lee Jones", + description: "Rust misc device sample", + license: "GPL", +} + +#[pin_data] +struct RustMiscDeviceModule { + #[pin] + _miscdev: MiscDeviceRegistration<RustMiscDevice>, +} + +impl kernel::InPlaceModule for RustMiscDeviceModule { + fn init(_module: &'static ThisModule) -> impl PinInit<Self, Error> { + pr_info!("Initialising Rust Misc Device Sample\n"); + + let options = MiscDeviceOptions { + name: c_str!("rust-misc-device"), + }; + + try_pin_init!(Self { + _miscdev <- MiscDeviceRegistration::register(options), + }) + } +} + +struct Inner { + value: i32, +} + +#[pin_data(PinnedDrop)] +struct RustMiscDevice { + #[pin] + inner: Mutex<Inner>, + dev: ARef<Device>, +} + +#[vtable] +impl MiscDevice for RustMiscDevice { + type Ptr = Pin<KBox<Self>>; + + fn open(_file: &File, misc: &MiscDeviceRegistration<Self>) -> Result<Pin<KBox<Self>>> { + let dev = ARef::from(misc.device()); + + dev_info!(dev, "Opening Rust Misc Device Sample\n"); + + KBox::try_pin_init( + try_pin_init! { + RustMiscDevice { + inner <- new_mutex!( Inner{ value: 0_i32 } ), + dev: dev, + } + }, + GFP_KERNEL, + ) + } + + fn ioctl(me: Pin<&RustMiscDevice>, _file: &File, cmd: u32, arg: usize) -> Result<isize> { + dev_info!(me.dev, "IOCTLing Rust Misc Device Sample\n"); + + let size = _IOC_SIZE(cmd); + + match cmd { + RUST_MISC_DEV_GET_VALUE => me.get_value(UserSlice::new(arg, size).writer())?, + RUST_MISC_DEV_SET_VALUE => me.set_value(UserSlice::new(arg, size).reader())?, + RUST_MISC_DEV_HELLO => me.hello()?, + _ => { + dev_err!(me.dev, "-> IOCTL not recognised: {}\n", cmd); + return Err(ENOTTY); + } + }; + + Ok(0) + } +} + +#[pinned_drop] +impl PinnedDrop for RustMiscDevice { + fn drop(self: Pin<&mut Self>) { + dev_info!(self.dev, "Exiting the Rust Misc Device Sample\n"); + } +} + +impl RustMiscDevice { + fn set_value(&self, mut reader: UserSliceReader) -> Result<isize> { + let new_value = reader.read::<i32>()?; + let mut guard = self.inner.lock(); + + dev_info!( + self.dev, + "-> Copying data from userspace (value: {})\n", + new_value + ); + + guard.value = new_value; + Ok(0) + } + + fn get_value(&self, mut writer: UserSliceWriter) -> Result<isize> { + let guard = self.inner.lock(); + let value = guard.value; + + // Free-up the lock and use our locally cached instance from here + drop(guard); + + dev_info!( + self.dev, + "-> Copying data to userspace (value: {})\n", + &value + ); + + writer.write::<i32>(&value)?; + Ok(0) + } + + fn hello(&self) -> Result<isize> { + dev_info!(self.dev, "-> Hello from the Rust Misc Device\n"); + + Ok(0) + } +} |