# Goal of this patch
Use udev to change or detect flash device instead of hardcoded pinephone device file.
Inspired by phosh flash manager because it works in many devices. https://gitlab.gnome.org/World/Phosh/phosh/-/blob/main/src/torch-manager.c?ref_type=heads#L168-198
# Remaining work
- [x] Minimal project for testing
- [x] Try to build for pmOS to test in my device (OP6)
- [x] Need udev rules to work (Require write permission in brightness)
# Stabilization
- [x] read permission removed in max_brightness to check if no crash
> "Failed to read max_brightness from udev device" in log
- [x] read permission removed in brightness to check if no crash
> "Failed to read brightness from udev device" in log
- [x] "Break" match in my side to check if no crash occured when no device found
> "No flashlight found" in log
# Minimal project
It run in my device perfectly, it find device, get current value and max value and toggle flashlight. It require **root** permissions to write in device file.
```cpp
#include <iostream>
#include <cstring>
#include <libudev.h>
#define TORCH_SUBSYSTEM "leds"
int main() {
struct udev* udev = udev_new();
struct udev_enumerate* enumerate = udev_enumerate_new(udev);
// Use to find all devices in subsystem "leds"
// And use match sysname to filter only flash or torch
// Example:
// - /sys/devices/platform/soc@0/c440000.spmi/spmi-0/0-03/c440000.spmi:pmic@3:led-controller@d300/leds/white:flash On OP6
// - /sys/devices/platform/soc@0/c440000.spmi/spmi-0/0-03/c440000.spmi:pmic@3:led-controller@d300/leds/yellow:flash On OP6
// - /sys/devices/platform/led-controller/leds/white:flash/brightness On pinephone
udev_enumerate_add_match_subsystem(enumerate, TORCH_SUBSYSTEM);
udev_enumerate_add_match_sysname(enumerate, "*:torch");
udev_enumerate_add_match_sysname(enumerate, "*:flash");
udev_enumerate_scan_devices(enumerate);
struct udev_list_entry *devices = udev_enumerate_get_list_entry(enumerate);
struct udev_list_entry *entry = udev_list_entry_get_next(devices);
if (entry == nullptr) {
std::cout << "No flashlight found" << std::endl;
return 1;
}
const char *path = udev_list_entry_get_name(entry);
struct udev_device *torch = udev_device_new_from_syspath(udev, path);
const char *max_brightness = udev_device_get_sysattr_value(torch, "max_brightness");
const char *brightness = udev_device_get_sysattr_value(torch, "brightness");
bool enabled = std::strcmp(brightness, "0") != 0;
udev_device_set_sysattr_value(torch, "brightness", const_cast<char*>(enabled ? "0" : max_brightness));
udev_device_unref(torch);
udev_enumerate_unref(enumerate);
udev_unref(udev);
return 0;
}
```
Build with `g++ torch.cpp -ludev -o torch`
Run with `sudo ./torch`
# Important info
- **udev** dependencies added
- destructor for flashlightutil added to unref udev_device
# Require udev rules
Files `/etc/udev/rules.d/99-flashlight.rules`
```bash
# Allow everyone to set brightness of flashlight (Required for plasma-mobile flashlightplugin)
SUBSYSTEMS=="leds", KERNEL=="*:flash|*:torch", RUN+="/bin/chmod 666 %S%p/brightness"
```
pmOS : See to add depends `eudev` and makedepends `eudev-dev`
Upgrading on pmOS from Plasma 5, where we used to ship custom configs seems to have kwin get stuck having the kdecoration plugin disabled. Manually enable it.
The old UI was very confusing to use, I changed it so that:
- Dialogs are used for the time and date picker, with user confirmation for changes
- Tumblers are not used for the time picker, use the time picker component from kclock
- Removed seconds selector (since it was always wrong)
- Fixed the time zone selector (it didn't work before)
- Properly support 24 hour time in the time picker
Fixes https://invent.kde.org/plasma/plasma-mobile/-/issues/286
