components/
text_screen.rs

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1// Licensed under the Apache License, Version 2.0 or the MIT License.
2// SPDX-License-Identifier: Apache-2.0 OR MIT
3// Copyright Tock Contributors 2022.
4
5//! Components for the Text Screen.
6//!
7//! Buffer Size
8//! -----------
9//!
10//! Displays can receive a large amount of data and having larger transfer buffers
11//! optimizes the number of bus writes.
12//!
13//! As memory is limited on some MCUs, the `components::screen_buffer_size``
14//! macro allows users to define the size of the screen buffer.
15//!
16//! Usage
17//! -----
18//!
19//! ```rust
20//! let text_screen =
21//!     components::text_screen::TextScreenComponent::new(board_kernel, tft)
22//!         .finalize(components::text_screen_component_static!(40960));
23//! ```
24//!
25
26use capsules_extra::text_screen::TextScreen;
27use core::mem::MaybeUninit;
28use kernel::capabilities;
29use kernel::component::Component;
30use kernel::create_capability;
31
32#[macro_export]
33macro_rules! text_screen_component_static {
34    ($s:literal $(,)?) => {{
35        let buffer = kernel::static_buf!([u8; $s]);
36        let screen = kernel::static_buf!(capsules_extra::text_screen::TextScreen);
37
38        (buffer, screen)
39    };};
40}
41
42pub struct TextScreenComponent<const SCREEN_BUF_LEN: usize> {
43    board_kernel: &'static kernel::Kernel,
44    driver_num: usize,
45    text_screen: &'static dyn kernel::hil::text_screen::TextScreen<'static>,
46}
47
48impl<const SCREEN_BUF_LEN: usize> TextScreenComponent<SCREEN_BUF_LEN> {
49    pub fn new(
50        board_kernel: &'static kernel::Kernel,
51        driver_num: usize,
52        text_screen: &'static dyn kernel::hil::text_screen::TextScreen<'static>,
53    ) -> TextScreenComponent<SCREEN_BUF_LEN> {
54        TextScreenComponent {
55            board_kernel,
56            driver_num,
57            text_screen,
58        }
59    }
60}
61
62impl<const SCREEN_BUF_LEN: usize> Component for TextScreenComponent<SCREEN_BUF_LEN> {
63    type StaticInput = (
64        &'static mut MaybeUninit<[u8; SCREEN_BUF_LEN]>,
65        &'static mut MaybeUninit<TextScreen<'static>>,
66    );
67    type Output = &'static TextScreen<'static>;
68
69    fn finalize(self, static_input: Self::StaticInput) -> Self::Output {
70        let grant_cap = create_capability!(capabilities::MemoryAllocationCapability);
71        let grant_text_screen = self.board_kernel.create_grant(self.driver_num, &grant_cap);
72
73        let buffer = static_input.0.write([0; SCREEN_BUF_LEN]);
74
75        let text_screen =
76            static_input
77                .1
78                .write(TextScreen::new(self.text_screen, buffer, grant_text_screen));
79
80        kernel::hil::text_screen::TextScreen::set_client(self.text_screen, Some(text_screen));
81
82        text_screen
83    }
84}
components/text_screen.rs

components/
text_screen.rs
