starnix_modules_touch_power_policy/
lib.rs

1// Copyright 2024 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use starnix_core::device::DeviceOps;
6use starnix_core::task::dynamic_thread_spawner::SpawnRequestBuilder;
7use starnix_core::task::{CurrentTask, Kernel, LockupDetectorReceiver};
8use starnix_core::vfs::buffers::{InputBuffer, OutputBuffer};
9use starnix_core::vfs::{
10    CloseFreeSafe, FileObject, FileOps, NamespaceNode, fileops_impl_nonseekable,
11    fileops_impl_noop_sync,
12};
13use starnix_logging::{log_error, log_info};
14use starnix_sync::{LockDepMutex, TouchPowerPolicyEnabledLock};
15use starnix_uapi::device_id::DeviceId;
16use starnix_uapi::error;
17use starnix_uapi::errors::Errno;
18use starnix_uapi::open_flags::OpenFlags;
19use std::sync::Arc;
20use std::sync::mpsc::Sender;
21use zerocopy::IntoBytes;
22
23#[derive(Clone)]
24pub struct TouchPowerPolicyDevice {
25    touch_power_file: Arc<TouchPowerPolicyFile>,
26}
27
28impl TouchPowerPolicyDevice {
29    pub fn new(touch_standby_sender: Sender<bool>) -> Self {
30        TouchPowerPolicyDevice { touch_power_file: TouchPowerPolicyFile::new(touch_standby_sender) }
31    }
32
33    pub fn register(self, kernel: &Kernel) {
34        let registry = &kernel.device_registry;
35        registry
36            .register_dyn_device(
37                kernel,
38                "touch_standby".into(),
39                registry.objects.starnix_class(),
40                self,
41            )
42            .expect("can register touch_standby device");
43    }
44
45    pub fn start_relay(
46        &self,
47        kernel: &Kernel,
48        touch_standby_receiver: LockupDetectorReceiver<bool>,
49    ) {
50        let slf = self.clone();
51        let closure = move |_current_task: &CurrentTask| {
52            let mut prev_enabled = true;
53            while let Ok(touch_enabled) = touch_standby_receiver.recv() {
54                if touch_enabled != prev_enabled {
55                    slf.notify_standby_state_changed(touch_enabled);
56                }
57                prev_enabled = touch_enabled;
58            }
59            log_error!("touch_standby relay was terminated unexpectedly.");
60        };
61        let req = SpawnRequestBuilder::new()
62            .with_debug_name("touch-power-policy-relay")
63            .with_sync_closure(closure)
64            .build();
65        kernel.kthreads.spawner().spawn_from_request(req);
66    }
67
68    fn notify_standby_state_changed(&self, touch_enabled: bool) {
69        // TODO(b/341142285): notify input pipeline that touch_standby state has changed
70        log_info!("touch enabled: {:?}", touch_enabled);
71    }
72}
73
74impl DeviceOps for TouchPowerPolicyDevice {
75    fn open(
76        &self,
77        _current_task: &CurrentTask,
78        _devt: DeviceId,
79        _node: &NamespaceNode,
80        _flags: OpenFlags,
81    ) -> Result<Box<dyn FileOps>, Errno> {
82        let touch_policy_file = self.touch_power_file.clone();
83        Ok(Box::new(touch_policy_file))
84    }
85}
86
87pub struct TouchPowerPolicyFile {
88    // When false, Input Pipeline suspends processing of all touch events.
89    touch_enabled: LockDepMutex<bool, TouchPowerPolicyEnabledLock>,
90    // Sender used to send changes to `touch_standby` to the device relay
91    touch_standby_sender: Sender<bool>,
92}
93
94impl TouchPowerPolicyFile {
95    pub fn new(touch_standby_sender: Sender<bool>) -> Arc<Self> {
96        Arc::new(TouchPowerPolicyFile { touch_enabled: true.into(), touch_standby_sender })
97    }
98}
99
100/// `TouchPowerPolicyFile` doesn't implement the `close` method.
101impl CloseFreeSafe for TouchPowerPolicyFile {}
102impl FileOps for TouchPowerPolicyFile {
103    fileops_impl_nonseekable!();
104    fileops_impl_noop_sync!();
105
106    fn read(
107        &self,
108        _file: &FileObject,
109        _current_task: &CurrentTask,
110        offset: usize,
111        data: &mut dyn OutputBuffer,
112    ) -> Result<usize, Errno> {
113        debug_assert!(offset == 0);
114        let touch_enabled = self.touch_enabled.lock().to_owned();
115        data.write_all(touch_enabled.as_bytes())
116    }
117
118    fn write(
119        &self,
120        _file: &FileObject,
121        _current_task: &CurrentTask,
122        _offset: usize,
123        data: &mut dyn InputBuffer,
124    ) -> Result<usize, Errno> {
125        let content = data.read_all()?;
126        let sys_touch_standby = match &*content {
127            b"0" | b"0\n" => false,
128            b"1" | b"1\n" => true,
129            _ => {
130                log_error!("Invalid touch_standby value - must be 0 or 1");
131                return error!(EINVAL);
132            }
133        };
134        *self.touch_enabled.lock() = sys_touch_standby;
135        if let Err(e) = self.touch_standby_sender.send(sys_touch_standby) {
136            log_error!("unable to send recent touch_standby state to device relay: {:?}", e);
137        }
138        Ok(content.len())
139    }
140}
starnix_modules_touch_power_policy/lib.rs

starnix_modules_touch_power_policy/
lib.rs
