refactor(core): provide backlight values from Rust

core/embed/rust/librust_qstr.h

@@ -6,14 +6,20 @@
 
 static void _librust_qstrs(void) {
   MP_QSTR_;
+  MP_QSTR_BacklightLevels;
   MP_QSTR_CANCELLED;
   MP_QSTR_CONFIRMED;
+  MP_QSTR_DIM;
   MP_QSTR_INFO;
+  MP_QSTR_LOW;
   MP_QSTR_LayoutObj;
+  MP_QSTR_MAX;
   MP_QSTR_MESSAGE_NAME;
   MP_QSTR_MESSAGE_WIRE_TYPE;
   MP_QSTR_Msg;
   MP_QSTR_MsgDef;
+  MP_QSTR_NONE;
+  MP_QSTR_NORMAL;
   MP_QSTR_TR;
   MP_QSTR_TranslationsHeader;
   MP_QSTR___dict__;

core/embed/rust/src/ui/backlight.rs

@@ -0,0 +1,43 @@
+use crate::{
+    error::Error,
+    micropython::{ffi, obj::Obj, qstr::Qstr, simple_type::SimpleTypeObj, typ::Type, util},
+    ui::{ui_features::ModelUI, UIFeaturesCommon},
+};
+
+/*
+ * This whole module should be removed, in favor of fully
+ * moving backlight control into Rust. Relatively easy to do, but not
+ * necessary right now. Filed as https://github.com/trezor/trezor-firmware/issues/3849
+ *
+ * Consider this module temporary. (yeah yeah everyone knows "temporary"
+ * things stay forever. Written in May 2024.)
+ */
+
+static BACKLIGHT_LEVELS_TYPE: Type = obj_type! {
+    name: Qstr::MP_QSTR_BacklightLevels,
+    attr_fn: backlight_levels_attr,
+};
+
+unsafe extern "C" fn backlight_levels_attr(_self_in: Obj, attr: ffi::qstr, dest: *mut Obj) {
+    let block = || {
+        let arg = unsafe { dest.read() };
+        if !arg.is_null() {
+            // Null destination would mean a `setattr`.
+            return Err(Error::TypeError);
+        }
+        let attr = Qstr::from_u16(attr as _);
+        let value = match attr {
+            Qstr::MP_QSTR_NONE => ModelUI::get_backlight_none(),
+            Qstr::MP_QSTR_NORMAL => ModelUI::get_backlight_normal(),
+            Qstr::MP_QSTR_LOW => ModelUI::get_backlight_low(),
+            Qstr::MP_QSTR_DIM => ModelUI::get_backlight_dim(),
+            Qstr::MP_QSTR_MAX => ModelUI::get_backlight_max(),
+            _ => return Err(Error::AttributeError(attr)),
+        };
+        unsafe { dest.write(value.into()) };
+        Ok(())
+    };
+    unsafe { util::try_or_raise(block) }
+}
+
+pub static BACKLIGHT_LEVELS_OBJ: SimpleTypeObj = SimpleTypeObj::new(&BACKLIGHT_LEVELS_TYPE);

core/embed/rust/src/ui/mod.rs

@@ -2,6 +2,8 @@
 pub mod macros;
 
 pub mod animation;
+#[cfg(feature = "micropython")]
+pub mod backlight;
 pub mod button_request;
 pub mod component;
 pub mod constant;

core/embed/rust/src/ui/model_mercury/layout.rs

@@ -44,8 +44,8 @@ use super::{
         FidoMsg, Frame, FrameMsg, Homescreen, HomescreenMsg, IconDialog, Lockscreen, MnemonicInput,
         MnemonicKeyboard, MnemonicKeyboardMsg, PassphraseKeyboard, PassphraseKeyboardMsg,
         PinKeyboard, PinKeyboardMsg, Progress, PromptScreen, SelectWordCount, SelectWordCountMsg,
-        SetBrightnessDialog, SimplePage, Slip39Input, StatusScreen, SwipeUpScreen, SwipeUpScreenMsg,
+        SetBrightnessDialog, SimplePage, Slip39Input, StatusScreen, SwipeUpScreen,
-        VerticalMenu, VerticalMenuChoiceMsg,
+        SwipeUpScreenMsg, VerticalMenu, VerticalMenuChoiceMsg,
     },
     flow, theme,
 };
@@ -2033,6 +2033,17 @@ pub static mp_module_trezorui2: Module = obj_module! {
     /// ) -> LayoutObj[UiResult]:
     ///     """Total summary and hold to confirm."""
     Qstr::MP_QSTR_flow_confirm_summary => obj_fn_kw!(0, flow::new_confirm_summary).as_obj(),
+
+    /// class BacklightLevels:
+    ///     """Backlight levels. Values dynamically update based on user settings."""
+    ///     MAX: ClassVar[int]
+    ///     NORMAL: ClassVar[int]
+    ///     LOW: ClassVar[int]
+    ///     DIM: ClassVar[int]
+    ///     NONE: ClassVar[int]
+    ///
+    /// mock:global
+    Qstr::MP_QSTR_BacklightLevels => BACKLIGHT_LEVELS_OBJ.as_obj(),
 };
 
 #[cfg(test)]

core/embed/rust/src/ui/model_mercury/mod.rs

@@ -1,4 +1,5 @@
 use super::{geometry::Rect, UIFeaturesCommon};
+use crate::ui::model_mercury::theme::backlight;
 
 #[cfg(feature = "bootloader")]
 pub mod bootloader;
@@ -16,19 +17,44 @@ pub mod shapes;
 pub struct ModelMercuryFeatures;
 
 impl UIFeaturesCommon for ModelMercuryFeatures {
+    #[cfg(feature = "backlight")]
     fn fadein() {
-        #[cfg(feature = "backlight")]
+        crate::ui::display::fade_backlight_duration(backlight::get_backlight_normal(), 150);
-        crate::ui::display::fade_backlight_duration(theme::backlight::get_backlight_normal(), 150);
     }
 
+    #[cfg(feature = "backlight")]
     fn fadeout() {
-        #[cfg(feature = "backlight")]
+        crate::ui::display::fade_backlight_duration(backlight::get_backlight_dim(), 150);
-        crate::ui::display::fade_backlight_duration(theme::backlight::get_backlight_dim(), 150);
     }
 
-    fn backlight_on() {
     #[cfg(feature = "backlight")]
-        crate::ui::display::set_backlight(theme::backlight::get_backlight_normal());
+    fn backlight_on() {
+        crate::ui::display::set_backlight(backlight::get_backlight_normal());
+    }
+
+    #[cfg(feature = "backlight")]
+    fn get_backlight_none() -> u16 {
+        backlight::get_backlight_none()
+    }
+
+    #[cfg(feature = "backlight")]
+    fn get_backlight_normal() -> u16 {
+        backlight::get_backlight_normal()
+    }
+
+    #[cfg(feature = "backlight")]
+    fn get_backlight_low() -> u16 {
+        backlight::get_backlight_low()
+    }
+
+    #[cfg(feature = "backlight")]
+    fn get_backlight_dim() -> u16 {
+        backlight::get_backlight_dim()
+    }
+
+    #[cfg(feature = "backlight")]
+    fn get_backlight_max() -> u16 {
+        backlight::get_backlight_max()
     }
 
     const SCREEN: Rect = constant::SCREEN;

core/embed/rust/src/ui/model_mercury/theme/backlight.rs

@@ -5,7 +5,7 @@ use crate::storage;
 const BACKLIGHT_NORMAL: u8 = 150;
 const BACKLIGHT_LOW: u8 = 45;
 const BACKLIGHT_DIM: u8 = 5;
-const BACKLIGHT_NONE: u8 = 2;
+const BACKLIGHT_NONE: u8 = 0;
 const BACKLIGHT_MIN: u8 = 10;
 const BACKLIGHT_MAX: u8 = 255;
 

core/embed/rust/src/ui/model_tr/layout.rs

@@ -13,6 +13,7 @@ use crate::{
     translations::TR,
     trezorhal::model,
     ui::{
+        backlight::BACKLIGHT_LEVELS_OBJ,
         component::{
             base::Component,
             connect::Connect,
@@ -2037,4 +2038,15 @@ pub static mp_module_trezorui2: Module = obj_module! {
     /// def show_wait_text(message: str, /) -> None:
     ///     """Show single-line text in the middle of the screen."""
     Qstr::MP_QSTR_show_wait_text => obj_fn_1!(new_show_wait_text).as_obj(),
+
+    /// class BacklightLevels:
+    ///     """Backlight levels. Values dynamically update based on user settings."""
+    ///     MAX: ClassVar[int]
+    ///     NORMAL: ClassVar[int]
+    ///     LOW: ClassVar[int]
+    ///     DIM: ClassVar[int]
+    ///     NONE: ClassVar[int]
+    ///
+    /// mock:global
+    Qstr::MP_QSTR_BacklightLevels => BACKLIGHT_LEVELS_OBJ.as_obj(),
 };

core/embed/rust/src/ui/model_tt/layout.rs

@@ -10,6 +10,7 @@ use crate::{
     translations::TR,
     trezorhal::model,
     ui::{
+        backlight::BACKLIGHT_LEVELS_OBJ,
         component::{
             base::ComponentExt,
             connect::Connect,
@@ -2117,6 +2118,17 @@ pub static mp_module_trezorui2: Module = obj_module! {
     /// def show_wait_text(message: str, /) -> LayoutObj[None]:
     ///     """Show single-line text in the middle of the screen."""
     Qstr::MP_QSTR_show_wait_text => obj_fn_1!(new_show_wait_text).as_obj(),
+
+    /// class BacklightLevels:
+    ///     """Backlight levels. Values dynamically update based on user settings."""
+    ///     MAX: ClassVar[int]
+    ///     NORMAL: ClassVar[int]
+    ///     LOW: ClassVar[int]
+    ///     DIM: ClassVar[int]
+    ///     NONE: ClassVar[int]
+    ///
+    /// mock:global
+    Qstr::MP_QSTR_BacklightLevels => BACKLIGHT_LEVELS_OBJ.as_obj(),
 };
 
 #[cfg(test)]

core/embed/rust/src/ui/model_tt/mod.rs

@@ -20,21 +20,44 @@ use crate::ui::{
 pub struct ModelTTFeatures;
 
 impl UIFeaturesCommon for ModelTTFeatures {
+    #[cfg(feature = "backlight")]
     fn fadein() {
-        #[cfg(feature = "backlight")]
         crate::ui::display::fade_backlight_duration(backlight::get_backlight_normal(), 150);
     }
-
+    #[cfg(feature = "backlight")]
     fn fadeout() {
-        #[cfg(feature = "backlight")]
         crate::ui::display::fade_backlight_duration(backlight::get_backlight_normal(), 150);
     }
-
-    fn backlight_on() {
     #[cfg(feature = "backlight")]
+    fn backlight_on() {
         crate::ui::display::set_backlight(backlight::get_backlight_normal());
     }
 
+    #[cfg(feature = "backlight")]
+    fn get_backlight_none() -> u16 {
+        backlight::get_backlight_none()
+    }
+
+    #[cfg(feature = "backlight")]
+    fn get_backlight_normal() -> u16 {
+        backlight::get_backlight_normal()
+    }
+
+    #[cfg(feature = "backlight")]
+    fn get_backlight_low() -> u16 {
+        backlight::get_backlight_low()
+    }
+
+    #[cfg(feature = "backlight")]
+    fn get_backlight_dim() -> u16 {
+        backlight::get_backlight_dim()
+    }
+
+    #[cfg(feature = "backlight")]
+    fn get_backlight_max() -> u16 {
+        backlight::get_backlight_max()
+    }
+
     const SCREEN: Rect = constant::SCREEN;
 
     fn screen_fatal_error(title: &str, msg: &str, footer: &str) {

core/embed/rust/src/ui/model_tt/theme/backlight.rs

@@ -5,7 +5,7 @@ use crate::storage;
 const BACKLIGHT_NORMAL: u8 = 150;
 const BACKLIGHT_LOW: u8 = 45;
 const BACKLIGHT_DIM: u8 = 5;
-const BACKLIGHT_NONE: u8 = 2;
+const BACKLIGHT_NONE: u8 = 0;
 const BACKLIGHT_MIN: u8 = 10;
 const BACKLIGHT_MAX: u8 = 255;
 

core/embed/rust/src/ui/ui_features.rs

@@ -11,6 +11,22 @@ pub trait UIFeaturesCommon {
     fn fadeout() {}
     fn backlight_on() {}
 
+    fn get_backlight_none() -> u16 {
+        0
+    }
+    fn get_backlight_normal() -> u16 {
+        0
+    }
+    fn get_backlight_low() -> u16 {
+        0
+    }
+    fn get_backlight_dim() -> u16 {
+        0
+    }
+    fn get_backlight_max() -> u16 {
+        0
+    }
+
     const SCREEN: Rect;
 
     fn screen_fatal_error(title: &str, msg: &str, footer: &str);

core/mocks/generated/trezorui2.pyi

@@ -592,6 +592,16 @@ def flow_confirm_summary(
     br_type: str,
 ) -> LayoutObj[UiResult]:
     """Total summary and hold to confirm."""
+
+
+# rust/src/ui/model_mercury/layout.rs
+class BacklightLevels:
+    """Backlight levels. Values dynamically update based on user settings."""
+    MAX: ClassVar[int]
+    NORMAL: ClassVar[int]
+    LOW: ClassVar[int]
+    DIM: ClassVar[int]
+    NONE: ClassVar[int]
 CONFIRMED: UiResult
 CANCELLED: UiResult
 INFO: UiResult
@@ -1586,3 +1596,13 @@ def confirm_firmware_update(
 # rust/src/ui/model_tt/layout.rs
 def show_wait_text(message: str, /) -> LayoutObj[None]:
     """Show single-line text in the middle of the screen."""
+
+
+# rust/src/ui/model_tt/layout.rs
+class BacklightLevels:
+    """Backlight levels. Values dynamically update based on user settings."""
+    MAX: ClassVar[int]
+    NORMAL: ClassVar[int]
+    LOW: ClassVar[int]
+    DIM: ClassVar[int]
+    NONE: ClassVar[int]

core/src/all_modules.py

@@ -195,8 +195,6 @@ trezor.ui.layouts.tt.recovery
 import trezor.ui.layouts.tt.recovery
 trezor.ui.layouts.tt.reset
 import trezor.ui.layouts.tt.reset
-trezor.ui.style
-import trezor.ui.style
 trezor.utils
 import trezor.utils
 trezor.wire

core/src/apps/base.py

@@ -437,7 +437,7 @@ def reload_settings_from_storage() -> None:
     )
     wire.EXPERIMENTAL_ENABLED = storage_device.get_experimental_features()
     if ui.display.orientation() != storage_device.get_rotation():
-        ui.backlight_fade(ui.style.get_backlight_dim())
+        ui.backlight_fade(ui.BacklightLevels.DIM)
         ui.display.orientation(storage_device.get_rotation())
 
 

core/src/boot.py

@@ -49,7 +49,7 @@ async def bootscreen() -> None:
 
             if can_lock_device():
                 enforce_welcome_screen_duration()
-                ui.backlight_fade(ui.style.get_backlight_dim())
+                ui.backlight_fade(ui.BacklightLevels.NONE)
                 ui.display.orientation(storage.device.get_rotation())
                 await lockscreen
                 await verify_user_pin()
@@ -64,7 +64,7 @@ async def bootscreen() -> None:
                 if rotation != ui.display.orientation():
                     # there is a slight delay before next screen is shown,
                     # so we don't fade unless there is a change of orientation
-                    ui.backlight_fade(ui.style.get_backlight_dim())
+                    ui.backlight_fade(ui.BacklightLevels.DIM)
                     ui.display.orientation(rotation)
                 allow_all_loader_messages()
                 return

core/src/trezor/ui/__init__.py

@@ -4,6 +4,7 @@ from trezorui import Display
 from typing import TYPE_CHECKING, Any, Awaitable, Generator
 
 from trezor import loop, utils
+from trezorui2 import BacklightLevels
 
 if TYPE_CHECKING:
     from typing import Generic, TypeVar
@@ -53,21 +54,17 @@ if utils.EMULATOR or utils.INTERNAL_MODEL in ("T1B1", "T2B1"):
     loop.after_step_hook = refresh
 
 
-# import style later to avoid circular dep
-from trezor.ui import style  # isort:skip
-
-
 async def _alert(count: int) -> None:
     short_sleep = loop.sleep(20)
     long_sleep = loop.sleep(80)
     for i in range(count * 2):
         if i % 2 == 0:
-            display.backlight(style.get_backlight_max())
+            display.backlight(BacklightLevels.MAX)
             await short_sleep
         else:
-            display.backlight(style.get_backlight_dim())
+            display.backlight(BacklightLevels.DIM)
             await long_sleep
-    display.backlight(style.get_backlight_normal())
+    display.backlight(BacklightLevels.NORMAL)
     global _alert_in_progress
     _alert_in_progress = False
 

core/src/trezor/ui/layouts/mercury/__init__.py

@@ -38,7 +38,7 @@ class RustLayout(ui.Layout):
         self.timer = loop.Timer()
         self.layout.attach_timer_fn(self.set_timer)
         self._send_button_request()
-        self.backlight_level = ui.style.get_backlight_normal()
+        self.backlight_level = ui.BacklightLevels.NORMAL
 
     def set_timer(self, token: int, deadline: int) -> None:
         self.timer.schedule(deadline, token)
@@ -187,7 +187,7 @@ class RustLayout(ui.Layout):
                 )
 
     def _first_paint(self) -> None:
-        ui.backlight_fade(ui.style.get_backlight_none())
+        ui.backlight_fade(ui.BacklightLevels.NONE)
         self._paint()
 
         if __debug__ and self.should_notify_layout_change:
@@ -263,10 +263,10 @@ def draw_simple(layout: Any) -> None:
         raise RuntimeError
 
     layout.attach_timer_fn(dummy_set_timer)
-    ui.backlight_fade(ui.style.get_backlight_dim())
+    ui.backlight_fade(ui.BacklightLevels.DIM)
     layout.paint()
     ui.refresh()
-    ui.backlight_fade(ui.style.get_backlight_normal())
+    ui.backlight_fade(ui.BacklightLevels.NORMAL)
 
 
 async def raise_if_not_confirmed(

core/src/trezor/ui/layouts/mercury/homescreen.py

@@ -93,9 +93,9 @@ class Lockscreen(HomescreenBase):
         coinjoin_authorized: bool = False,
     ) -> None:
         self.bootscreen = bootscreen
-        self.backlight_level = ui.style.get_backlight_low()
+        self.backlight_level = ui.BacklightLevels.LOW
         if bootscreen:
-            self.backlight_level = ui.style.get_backlight_normal()
+            self.backlight_level = ui.BacklightLevels.NORMAL
 
         skip = (
             not bootscreen and storage_cache.homescreen_shown is self.RENDER_INDICATOR

core/src/trezor/ui/layouts/progress.py

@@ -34,11 +34,11 @@ class RustProgress:
         layout: Any,
     ):
         self.layout = layout
-        ui.backlight_fade(ui.style.get_backlight_dim())
+        ui.backlight_fade(ui.BacklightLevels.DIM)
         self.layout.attach_timer_fn(self.set_timer)
         self.layout.paint()
         ui.refresh()
-        ui.backlight_fade(ui.style.get_backlight_normal())
+        ui.backlight_fade(ui.BacklightLevels.NORMAL)
 
     def set_timer(self, token: int, deadline: int) -> None:
         raise RuntimeError  # progress layouts should not set timers

core/src/trezor/ui/layouts/tt/__init__.py

@@ -44,7 +44,7 @@ class RustLayout(LayoutParentType[T]):
         self.timer = loop.Timer()
         self.layout.attach_timer_fn(self.set_timer)
         self._send_button_request()
-        self.backlight_level = ui.style.get_backlight_normal()
+        self.backlight_level = ui.BacklightLevels.NORMAL
 
     def set_timer(self, token: int, deadline: int) -> None:
         self.timer.schedule(deadline, token)
@@ -193,7 +193,7 @@ class RustLayout(LayoutParentType[T]):
                 )
 
     def _first_paint(self) -> None:
-        ui.backlight_fade(ui.style.get_backlight_none())
+        ui.backlight_fade(ui.BacklightLevels.NONE)
         self._paint()
 
         if __debug__ and self.should_notify_layout_change:
@@ -269,10 +269,10 @@ def draw_simple(layout: trezorui2.LayoutObj[Any]) -> None:
         raise RuntimeError
 
     layout.attach_timer_fn(dummy_set_timer)
-    ui.backlight_fade(ui.style.get_backlight_dim())
+    ui.backlight_fade(ui.BacklightLevels.DIM)
     layout.paint()
     ui.refresh()
-    ui.backlight_fade(ui.style.get_backlight_normal())
+    ui.backlight_fade(ui.BacklightLevels.NORMAL)
 
 
 async def raise_if_not_confirmed(

core/src/trezor/ui/layouts/tt/homescreen.py

@@ -93,9 +93,9 @@ class Lockscreen(HomescreenBase):
         coinjoin_authorized: bool = False,
     ) -> None:
         self.bootscreen = bootscreen
-        self.backlight_level = ui.style.get_backlight_low()
+        self.backlight_level = ui.BacklightLevels.LOW
         if bootscreen:
-            self.backlight_level = ui.style.get_backlight_normal()
+            self.backlight_level = ui.BacklightLevels.NORMAL
 
         skip = (
             not bootscreen and storage_cache.homescreen_shown is self.RENDER_INDICATOR

core/src/trezor/ui/style.py

@@ -1,41 +0,0 @@
-from micropython import const
-
-import storage.device
-
-# backlight brightness
-_BACKLIGHT_NORMAL = const(150)
-_BACKLIGHT_LOW = const(45)
-_BACKLIGHT_DIM = const(5)
-_BACKLIGHT_NONE = const(0)
-_BACKLIGHT_MIN = const(10)
-_BACKLIGHT_MAX = const(255)
-
-
-def get_backlight_normal() -> int:
-    val = storage.device.get_brightness()
-    if val is None:
-        return _BACKLIGHT_NORMAL
-    return val
-
-
-def get_backlight_low() -> int:
-    val = storage.device.get_brightness()
-    if val is None or val > _BACKLIGHT_LOW:
-        return _BACKLIGHT_LOW
-    return val
-
-
-def get_backlight_dim() -> int:
-    return _BACKLIGHT_DIM
-
-
-def get_backlight_none() -> int:
-    return _BACKLIGHT_NONE
-
-
-def get_backlight_min() -> int:
-    return _BACKLIGHT_MIN
-
-
-def get_backlight_max() -> int:
-    return _BACKLIGHT_MAX