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Diffstat (limited to 'rust/hw/char/pl011/src/lib.rs')
| -rw-r--r-- | rust/hw/char/pl011/src/lib.rs | 586 |
1 files changed, 586 insertions, 0 deletions
diff --git a/rust/hw/char/pl011/src/lib.rs b/rust/hw/char/pl011/src/lib.rs new file mode 100644 index 0000000000..2939ee50c9 --- /dev/null +++ b/rust/hw/char/pl011/src/lib.rs @@ -0,0 +1,586 @@ +// Copyright 2024, Linaro Limited +// Author(s): Manos Pitsidianakis <manos.pitsidianakis@linaro.org> +// SPDX-License-Identifier: GPL-2.0-or-later +// +// PL011 QEMU Device Model +// +// This library implements a device model for the PrimeCell® UART (PL011) +// device in QEMU. +// +#![doc = include_str!("../README.md")] +//! # Library crate +//! +//! See [`PL011State`](crate::device::PL011State) for the device model type and +//! the [`registers`] module for register types. + +#![deny( + rustdoc::broken_intra_doc_links, + rustdoc::redundant_explicit_links, + clippy::correctness, + clippy::suspicious, + clippy::complexity, + clippy::perf, + clippy::cargo, + clippy::nursery, + clippy::style, + // restriction group + clippy::dbg_macro, + clippy::as_underscore, + clippy::assertions_on_result_states, + // pedantic group + clippy::doc_markdown, + clippy::borrow_as_ptr, + clippy::cast_lossless, + clippy::option_if_let_else, + clippy::missing_const_for_fn, + clippy::cognitive_complexity, + clippy::missing_safety_doc, + )] + +extern crate bilge; +extern crate bilge_impl; +extern crate qemu_api; + +pub mod device; +pub mod device_class; +pub mod memory_ops; + +pub const TYPE_PL011: &::core::ffi::CStr = c"pl011"; + +/// Offset of each register from the base memory address of the device. +/// +/// # Source +/// ARM DDI 0183G, Table 3-1 p.3-3 +#[doc(alias = "offset")] +#[allow(non_camel_case_types)] +#[repr(u64)] +#[derive(Debug)] +pub enum RegisterOffset { + /// Data Register + /// + /// A write to this register initiates the actual data transmission + #[doc(alias = "UARTDR")] + DR = 0x000, + /// Receive Status Register or Error Clear Register + #[doc(alias = "UARTRSR")] + #[doc(alias = "UARTECR")] + RSR = 0x004, + /// Flag Register + /// + /// A read of this register shows if transmission is complete + #[doc(alias = "UARTFR")] + FR = 0x018, + /// Fractional Baud Rate Register + /// + /// responsible for baud rate speed + #[doc(alias = "UARTFBRD")] + FBRD = 0x028, + /// `IrDA` Low-Power Counter Register + #[doc(alias = "UARTILPR")] + ILPR = 0x020, + /// Integer Baud Rate Register + /// + /// Responsible for baud rate speed + #[doc(alias = "UARTIBRD")] + IBRD = 0x024, + /// line control register (data frame format) + #[doc(alias = "UARTLCR_H")] + LCR_H = 0x02C, + /// Toggle UART, transmission or reception + #[doc(alias = "UARTCR")] + CR = 0x030, + /// Interrupt FIFO Level Select Register + #[doc(alias = "UARTIFLS")] + FLS = 0x034, + /// Interrupt Mask Set/Clear Register + #[doc(alias = "UARTIMSC")] + IMSC = 0x038, + /// Raw Interrupt Status Register + #[doc(alias = "UARTRIS")] + RIS = 0x03C, + /// Masked Interrupt Status Register + #[doc(alias = "UARTMIS")] + MIS = 0x040, + /// Interrupt Clear Register + #[doc(alias = "UARTICR")] + ICR = 0x044, + /// DMA control Register + #[doc(alias = "UARTDMACR")] + DMACR = 0x048, + ///// Reserved, offsets `0x04C` to `0x07C`. + //Reserved = 0x04C, +} + +impl core::convert::TryFrom<u64> for RegisterOffset { + type Error = u64; + + fn try_from(value: u64) -> Result<Self, Self::Error> { + macro_rules! case { + ($($discriminant:ident),*$(,)*) => { + /* check that matching on all macro arguments compiles, which means we are not + * missing any enum value; if the type definition ever changes this will stop + * compiling. + */ + const fn _assert_exhaustive(val: RegisterOffset) { + match val { + $(RegisterOffset::$discriminant => (),)* + } + } + + match value { + $(x if x == Self::$discriminant as u64 => Ok(Self::$discriminant),)* + _ => Err(value), + } + } + } + case! { DR, RSR, FR, FBRD, ILPR, IBRD, LCR_H, CR, FLS, IMSC, RIS, MIS, ICR, DMACR } + } +} + +pub mod registers { + //! Device registers exposed as typed structs which are backed by arbitrary + //! integer bitmaps. [`Data`], [`Control`], [`LineControl`], etc. + //! + //! All PL011 registers are essentially 32-bit wide, but are typed here as + //! bitmaps with only the necessary width. That is, if a struct bitmap + //! in this module is for example 16 bits long, it should be conceived + //! as a 32-bit register where the unmentioned higher bits are always + //! unused thus treated as zero when read or written. + use bilge::prelude::*; + + // TODO: FIFO Mode has different semantics + /// Data Register, `UARTDR` + /// + /// The `UARTDR` register is the data register. + /// + /// For words to be transmitted: + /// + /// - if the FIFOs are enabled, data written to this location is pushed onto + /// the transmit + /// FIFO + /// - if the FIFOs are not enabled, data is stored in the transmitter + /// holding register (the + /// bottom word of the transmit FIFO). + /// + /// The write operation initiates transmission from the UART. The data is + /// prefixed with a start bit, appended with the appropriate parity bit + /// (if parity is enabled), and a stop bit. The resultant word is then + /// transmitted. + /// + /// For received words: + /// + /// - if the FIFOs are enabled, the data byte and the 4-bit status (break, + /// frame, parity, + /// and overrun) is pushed onto the 12-bit wide receive FIFO + /// - if the FIFOs are not enabled, the data byte and status are stored in + /// the receiving + /// holding register (the bottom word of the receive FIFO). + /// + /// The received data byte is read by performing reads from the `UARTDR` + /// register along with the corresponding status information. The status + /// information can also be read by a read of the `UARTRSR/UARTECR` + /// register. + /// + /// # Note + /// + /// You must disable the UART before any of the control registers are + /// reprogrammed. When the UART is disabled in the middle of + /// transmission or reception, it completes the current character before + /// stopping. + /// + /// # Source + /// ARM DDI 0183G 3.3.1 Data Register, UARTDR + #[bitsize(16)] + #[derive(Clone, Copy, DebugBits, FromBits)] + #[doc(alias = "UARTDR")] + pub struct Data { + _reserved: u4, + pub data: u8, + pub framing_error: bool, + pub parity_error: bool, + pub break_error: bool, + pub overrun_error: bool, + } + + // TODO: FIFO Mode has different semantics + /// Receive Status Register / Error Clear Register, `UARTRSR/UARTECR` + /// + /// The UARTRSR/UARTECR register is the receive status register/error clear + /// register. Receive status can also be read from the `UARTRSR` + /// register. If the status is read from this register, then the status + /// information for break, framing and parity corresponds to the + /// data character read from the [Data register](Data), `UARTDR` prior to + /// reading the UARTRSR register. The status information for overrun is + /// set immediately when an overrun condition occurs. + /// + /// + /// # Note + /// The received data character must be read first from the [Data + /// Register](Data), `UARTDR` before reading the error status associated + /// with that data character from the `UARTRSR` register. This read + /// sequence cannot be reversed, because the `UARTRSR` register is + /// updated only when a read occurs from the `UARTDR` register. However, + /// the status information can also be obtained by reading the `UARTDR` + /// register + /// + /// # Source + /// ARM DDI 0183G 3.3.2 Receive Status Register/Error Clear Register, + /// UARTRSR/UARTECR + #[bitsize(8)] + #[derive(Clone, Copy, DebugBits, FromBits)] + pub struct ReceiveStatusErrorClear { + pub framing_error: bool, + pub parity_error: bool, + pub break_error: bool, + pub overrun_error: bool, + _reserved_unpredictable: u4, + } + + impl ReceiveStatusErrorClear { + pub fn reset(&mut self) { + // All the bits are cleared to 0 on reset. + *self = 0.into(); + } + } + + impl Default for ReceiveStatusErrorClear { + fn default() -> Self { + 0.into() + } + } + + #[bitsize(16)] + #[derive(Clone, Copy, DebugBits, FromBits)] + /// Flag Register, `UARTFR` + #[doc(alias = "UARTFR")] + pub struct Flags { + /// CTS Clear to send. This bit is the complement of the UART clear to + /// send, `nUARTCTS`, modem status input. That is, the bit is 1 + /// when `nUARTCTS` is LOW. + pub clear_to_send: bool, + /// DSR Data set ready. This bit is the complement of the UART data set + /// ready, `nUARTDSR`, modem status input. That is, the bit is 1 when + /// `nUARTDSR` is LOW. + pub data_set_ready: bool, + /// DCD Data carrier detect. This bit is the complement of the UART data + /// carrier detect, `nUARTDCD`, modem status input. That is, the bit is + /// 1 when `nUARTDCD` is LOW. + pub data_carrier_detect: bool, + /// BUSY UART busy. If this bit is set to 1, the UART is busy + /// transmitting data. This bit remains set until the complete + /// byte, including all the stop bits, has been sent from the + /// shift register. This bit is set as soon as the transmit FIFO + /// becomes non-empty, regardless of whether the UART is enabled + /// or not. + pub busy: bool, + /// RXFE Receive FIFO empty. The meaning of this bit depends on the + /// state of the FEN bit in the UARTLCR_H register. If the FIFO + /// is disabled, this bit is set when the receive holding + /// register is empty. If the FIFO is enabled, the RXFE bit is + /// set when the receive FIFO is empty. + pub receive_fifo_empty: bool, + /// TXFF Transmit FIFO full. The meaning of this bit depends on the + /// state of the FEN bit in the UARTLCR_H register. If the FIFO + /// is disabled, this bit is set when the transmit holding + /// register is full. If the FIFO is enabled, the TXFF bit is + /// set when the transmit FIFO is full. + pub transmit_fifo_full: bool, + /// RXFF Receive FIFO full. The meaning of this bit depends on the state + /// of the FEN bit in the UARTLCR_H register. If the FIFO is + /// disabled, this bit is set when the receive holding register + /// is full. If the FIFO is enabled, the RXFF bit is set when + /// the receive FIFO is full. + pub receive_fifo_full: bool, + /// Transmit FIFO empty. The meaning of this bit depends on the state of + /// the FEN bit in the [Line Control register](LineControl), + /// `UARTLCR_H`. If the FIFO is disabled, this bit is set when the + /// transmit holding register is empty. If the FIFO is enabled, + /// the TXFE bit is set when the transmit FIFO is empty. This + /// bit does not indicate if there is data in the transmit shift + /// register. + pub transmit_fifo_empty: bool, + /// `RI`, is `true` when `nUARTRI` is `LOW`. + pub ring_indicator: bool, + _reserved_zero_no_modify: u7, + } + + impl Flags { + pub fn reset(&mut self) { + // After reset TXFF, RXFF, and BUSY are 0, and TXFE and RXFE are 1 + self.set_receive_fifo_full(false); + self.set_transmit_fifo_full(false); + self.set_busy(false); + self.set_receive_fifo_empty(true); + self.set_transmit_fifo_empty(true); + } + } + + impl Default for Flags { + fn default() -> Self { + let mut ret: Self = 0.into(); + ret.reset(); + ret + } + } + + #[bitsize(16)] + #[derive(Clone, Copy, DebugBits, FromBits)] + /// Line Control Register, `UARTLCR_H` + #[doc(alias = "UARTLCR_H")] + pub struct LineControl { + /// 15:8 - Reserved, do not modify, read as zero. + _reserved_zero_no_modify: u8, + /// 7 SPS Stick parity select. + /// 0 = stick parity is disabled + /// 1 = either: + /// • if the EPS bit is 0 then the parity bit is transmitted and checked + /// as a 1 • if the EPS bit is 1 then the parity bit is + /// transmitted and checked as a 0. This bit has no effect when + /// the PEN bit disables parity checking and generation. See Table 3-11 + /// on page 3-14 for the parity truth table. + pub sticky_parity: bool, + /// WLEN Word length. These bits indicate the number of data bits + /// transmitted or received in a frame as follows: b11 = 8 bits + /// b10 = 7 bits + /// b01 = 6 bits + /// b00 = 5 bits. + pub word_length: WordLength, + /// FEN Enable FIFOs: + /// 0 = FIFOs are disabled (character mode) that is, the FIFOs become + /// 1-byte-deep holding registers 1 = transmit and receive FIFO + /// buffers are enabled (FIFO mode). + pub fifos_enabled: Mode, + /// 3 STP2 Two stop bits select. If this bit is set to 1, two stop bits + /// are transmitted at the end of the frame. The receive + /// logic does not check for two stop bits being received. + pub two_stops_bits: bool, + /// EPS Even parity select. Controls the type of parity the UART uses + /// during transmission and reception: + /// - 0 = odd parity. The UART generates or checks for an odd number of + /// 1s in the data and parity bits. + /// - 1 = even parity. The UART generates or checks for an even number + /// of 1s in the data and parity bits. + /// This bit has no effect when the `PEN` bit disables parity checking + /// and generation. See Table 3-11 on page 3-14 for the parity + /// truth table. + pub parity: Parity, + /// 1 PEN Parity enable: + /// + /// - 0 = parity is disabled and no parity bit added to the data frame + /// - 1 = parity checking and generation is enabled. + /// + /// See Table 3-11 on page 3-14 for the parity truth table. + pub parity_enabled: bool, + /// BRK Send break. + /// + /// If this bit is set to `1`, a low-level is continually output on the + /// `UARTTXD` output, after completing transmission of the + /// current character. For the proper execution of the break command, + /// the software must set this bit for at least two complete + /// frames. For normal use, this bit must be cleared to `0`. + pub send_break: bool, + } + + impl LineControl { + pub fn reset(&mut self) { + // All the bits are cleared to 0 when reset. + *self = 0.into(); + } + } + + impl Default for LineControl { + fn default() -> Self { + 0.into() + } + } + + #[bitsize(1)] + #[derive(Clone, Copy, Debug, Eq, FromBits, PartialEq)] + /// `EPS` "Even parity select", field of [Line Control + /// register](LineControl). + pub enum Parity { + /// - 0 = odd parity. The UART generates or checks for an odd number of + /// 1s in the data and parity bits. + Odd = 0, + /// - 1 = even parity. The UART generates or checks for an even number + /// of 1s in the data and parity bits. + Even = 1, + } + + #[bitsize(1)] + #[derive(Clone, Copy, Debug, Eq, FromBits, PartialEq)] + /// `FEN` "Enable FIFOs" or Device mode, field of [Line Control + /// register](LineControl). + pub enum Mode { + /// 0 = FIFOs are disabled (character mode) that is, the FIFOs become + /// 1-byte-deep holding registers + Character = 0, + /// 1 = transmit and receive FIFO buffers are enabled (FIFO mode). + FIFO = 1, + } + + impl From<Mode> for bool { + fn from(val: Mode) -> Self { + matches!(val, Mode::FIFO) + } + } + + #[bitsize(2)] + #[derive(Clone, Copy, Debug, Eq, FromBits, PartialEq)] + /// `WLEN` Word length, field of [Line Control register](LineControl). + /// + /// These bits indicate the number of data bits transmitted or received in a + /// frame as follows: + pub enum WordLength { + /// b11 = 8 bits + _8Bits = 0b11, + /// b10 = 7 bits + _7Bits = 0b10, + /// b01 = 6 bits + _6Bits = 0b01, + /// b00 = 5 bits. + _5Bits = 0b00, + } + + /// Control Register, `UARTCR` + /// + /// The `UARTCR` register is the control register. All the bits are cleared + /// to `0` on reset except for bits `9` and `8` that are set to `1`. + /// + /// # Source + /// ARM DDI 0183G, 3.3.8 Control Register, `UARTCR`, Table 3-12 + #[bitsize(16)] + #[doc(alias = "UARTCR")] + #[derive(Clone, Copy, DebugBits, FromBits)] + pub struct Control { + /// `UARTEN` UART enable: 0 = UART is disabled. If the UART is disabled + /// in the middle of transmission or reception, it completes the current + /// character before stopping. 1 = the UART is enabled. Data + /// transmission and reception occurs for either UART signals or SIR + /// signals depending on the setting of the SIREN bit. + pub enable_uart: bool, + /// `SIREN` `SIR` enable: 0 = IrDA SIR ENDEC is disabled. `nSIROUT` + /// remains LOW (no light pulse generated), and signal transitions on + /// SIRIN have no effect. 1 = IrDA SIR ENDEC is enabled. Data is + /// transmitted and received on nSIROUT and SIRIN. UARTTXD remains HIGH, + /// in the marking state. Signal transitions on UARTRXD or modem status + /// inputs have no effect. This bit has no effect if the UARTEN bit + /// disables the UART. + pub enable_sir: bool, + /// `SIRLP` SIR low-power IrDA mode. This bit selects the IrDA encoding + /// mode. If this bit is cleared to 0, low-level bits are transmitted as + /// an active high pulse with a width of 3/ 16th of the bit period. If + /// this bit is set to 1, low-level bits are transmitted with a pulse + /// width that is 3 times the period of the IrLPBaud16 input signal, + /// regardless of the selected bit rate. Setting this bit uses less + /// power, but might reduce transmission distances. + pub sir_lowpower_irda_mode: u1, + /// Reserved, do not modify, read as zero. + _reserved_zero_no_modify: u4, + /// `LBE` Loopback enable. If this bit is set to 1 and the SIREN bit is + /// set to 1 and the SIRTEST bit in the Test Control register, UARTTCR + /// on page 4-5 is set to 1, then the nSIROUT path is inverted, and fed + /// through to the SIRIN path. The SIRTEST bit in the test register must + /// be set to 1 to override the normal half-duplex SIR operation. This + /// must be the requirement for accessing the test registers during + /// normal operation, and SIRTEST must be cleared to 0 when loopback + /// testing is finished. This feature reduces the amount of external + /// coupling required during system test. If this bit is set to 1, and + /// the SIRTEST bit is set to 0, the UARTTXD path is fed through to the + /// UARTRXD path. In either SIR mode or UART mode, when this bit is set, + /// the modem outputs are also fed through to the modem inputs. This bit + /// is cleared to 0 on reset, to disable loopback. + pub enable_loopback: bool, + /// `TXE` Transmit enable. If this bit is set to 1, the transmit section + /// of the UART is enabled. Data transmission occurs for either UART + /// signals, or SIR signals depending on the setting of the SIREN bit. + /// When the UART is disabled in the middle of transmission, it + /// completes the current character before stopping. + pub enable_transmit: bool, + /// `RXE` Receive enable. If this bit is set to 1, the receive section + /// of the UART is enabled. Data reception occurs for either UART + /// signals or SIR signals depending on the setting of the SIREN bit. + /// When the UART is disabled in the middle of reception, it completes + /// the current character before stopping. + pub enable_receive: bool, + /// `DTR` Data transmit ready. This bit is the complement of the UART + /// data transmit ready, `nUARTDTR`, modem status output. That is, when + /// the bit is programmed to a 1 then `nUARTDTR` is LOW. + pub data_transmit_ready: bool, + /// `RTS` Request to send. This bit is the complement of the UART + /// request to send, `nUARTRTS`, modem status output. That is, when the + /// bit is programmed to a 1 then `nUARTRTS` is LOW. + pub request_to_send: bool, + /// `Out1` This bit is the complement of the UART Out1 (`nUARTOut1`) + /// modem status output. That is, when the bit is programmed to a 1 the + /// output is 0. For DTE this can be used as Data Carrier Detect (DCD). + pub out_1: bool, + /// `Out2` This bit is the complement of the UART Out2 (`nUARTOut2`) + /// modem status output. That is, when the bit is programmed to a 1, the + /// output is 0. For DTE this can be used as Ring Indicator (RI). + pub out_2: bool, + /// `RTSEn` RTS hardware flow control enable. If this bit is set to 1, + /// RTS hardware flow control is enabled. Data is only requested when + /// there is space in the receive FIFO for it to be received. + pub rts_hardware_flow_control_enable: bool, + /// `CTSEn` CTS hardware flow control enable. If this bit is set to 1, + /// CTS hardware flow control is enabled. Data is only transmitted when + /// the `nUARTCTS` signal is asserted. + pub cts_hardware_flow_control_enable: bool, + } + + impl Control { + pub fn reset(&mut self) { + *self = 0.into(); + self.set_enable_receive(true); + self.set_enable_transmit(true); + } + } + + impl Default for Control { + fn default() -> Self { + let mut ret: Self = 0.into(); + ret.reset(); + ret + } + } + + /// Interrupt status bits in UARTRIS, UARTMIS, UARTIMSC + pub const INT_OE: u32 = 1 << 10; + pub const INT_BE: u32 = 1 << 9; + pub const INT_PE: u32 = 1 << 8; + pub const INT_FE: u32 = 1 << 7; + pub const INT_RT: u32 = 1 << 6; + pub const INT_TX: u32 = 1 << 5; + pub const INT_RX: u32 = 1 << 4; + pub const INT_DSR: u32 = 1 << 3; + pub const INT_DCD: u32 = 1 << 2; + pub const INT_CTS: u32 = 1 << 1; + pub const INT_RI: u32 = 1 << 0; + pub const INT_E: u32 = INT_OE | INT_BE | INT_PE | INT_FE; + pub const INT_MS: u32 = INT_RI | INT_DSR | INT_DCD | INT_CTS; + + #[repr(u32)] + pub enum Interrupt { + OE = 1 << 10, + BE = 1 << 9, + PE = 1 << 8, + FE = 1 << 7, + RT = 1 << 6, + TX = 1 << 5, + RX = 1 << 4, + DSR = 1 << 3, + DCD = 1 << 2, + CTS = 1 << 1, + RI = 1 << 0, + } + + impl Interrupt { + pub const E: u32 = INT_OE | INT_BE | INT_PE | INT_FE; + pub const MS: u32 = INT_RI | INT_DSR | INT_DCD | INT_CTS; + } +} + +// TODO: You must disable the UART before any of the control registers are +// reprogrammed. When the UART is disabled in the middle of transmission or +// reception, it completes the current character before stopping |