Add enums to the OpenBIOS SIO module and basic cleanup

[NotExactlySiev]

I copy pasted the enums from Psyqo. Tested it on Duckstation and it seems to be working fine.

[coderabbitai]

Walkthrough

The changes remove the legacy SIO interface and its associated files while introducing a new SIO header with a refined interface. In detail, the old struct SIO and its macro in hwregs.h, along with the sio1.c and sio1.h files, have been deleted. A new header (sio.h) now defines a SIOPort structure, updated enumerations, and an inline function (exchangeByte) to manage SIO operations. Additionally, references to the deprecated files have been removed from the build system, and related driver files have been refactored to use the new constants and function.

Changes

File(s)	Change Summary
src/mips/common/hardware/hwregs.h, src/mips/common/hardware/sio1.c, src/mips/common/hardware/sio1.h	Removed legacy SIO interface definitions, including the struct SIO, associated macro, and SIO1 initialization and transmission functions/declarations.
src/mips/common/hardware/sio.h	Introduced a new SIO interface with the SIOPort structure, a new SIOS macro, enumerations for control and status flags, and a static inline function exchangeByte for SIO data exchange.
src/mips/openbios/Makefile	Removed the reference to the deprecated sio1.c file from the build sources.
src/mips/openbios/sio0/card.c	Refactored SIO operations by replacing direct hardware register manipulation with calls to exchangeByte and using defined SIO control/status constants, streamlining the handling of serial communications.
src/mips/openbios/sio0/driver.c	Updated control register assignments by replacing hardcoded values with defined SIO control and status constants, enhancing clarity in hardware communication operations.

Sequence Diagram(s)

sequenceDiagram
    participant App as Application (card.c/driver.c)
    participant Ex as exchangeByte
    participant SIO as SIO Hardware (SIOPort)

    App->>Ex: Call exchangeByte(byte)
    Ex->>SIO: Read current FIFO value
    Ex->>SIO: Write new byte to FIFO
    Ex-->>App: Return exchanged byte

Loading

Poem

In a burrow of code, I hopped around,
Bidding farewell to old structures once found.
With fresh fields and flags so bright,
My inline hops made everything light.
Code now sings in a new array—happy bugs, I'll never stay!
🐇💻

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📜 Recent review details

Configuration used: .coderabbit.yaml
Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 0e6eda7 and b8a9080.

📒 Files selected for processing (7)

• src/mips/common/hardware/hwregs.h (0 hunks)
• src/mips/common/hardware/sio.h (1 hunks)
• src/mips/common/hardware/sio1.c (0 hunks)
• src/mips/common/hardware/sio1.h (0 hunks)
• src/mips/openbios/Makefile (0 hunks)
• src/mips/openbios/sio0/card.c (7 hunks)
• src/mips/openbios/sio0/driver.c (10 hunks)

💤 Files with no reviewable changes (4)

• src/mips/openbios/Makefile
• src/mips/common/hardware/sio1.c
• src/mips/common/hardware/sio1.h
• src/mips/common/hardware/hwregs.h

🧰 Additional context used

🧬 Code Graph Analysis (1)

src/mips/openbios/sio0/card.c (1)

src/mips/common/hardware/sio.h (1)

• exchangeByte (73-73)

⏰ Context from checks skipped due to timeout of 90000ms (11)

• GitHub Check: pcsx-redux (x86_64-linux)
• GitHub Check: pcsx-redux (aarch64-linux)
• GitHub Check: Codacy Static Code Analysis
• GitHub Check: build
• GitHub Check: macos-build-and-test-toolchain
• GitHub Check: cross-arm64
• GitHub Check: coverage
• GitHub Check: aur-build
• GitHub Check: asan
• GitHub Check: build-openbios
• GitHub Check: toolchain

🔇 Additional comments (20)

src/mips/openbios/sio0/card.c (6)

33-33: Good addition of the new SIO header

Including the new SIO header is essential for accessing the new SIOPort structure and constants.

---

99-102: Good use of SIO constants to improve readability

Replacing hardcoded values with named constants (SIO_CTRL_PORTSEL, SIO_CTRL_TXEN, SIO_CTRL_ACKIRQEN, SIO_CTRL_DTR) makes the code more readable and maintainable.

---

103-161: Excellent refactoring with exchangeByte

The replacement of direct FIFO manipulations with calls to the exchangeByte function significantly improves code readability and maintainability. This change also centralizes the error reset and interrupt clearing logic, reducing the chance of inconsistencies.

---

179-181: Consistent use of enumeration constants

The consistent use of SIO_CTRL_* constants throughout both handler functions demonstrates good coding practice for hardware register manipulation.

Also applies to: 262-262

---

161-161: Improved readability with SIO_STAT_RXRDY

Replacing raw bit masks with the SIO_STAT_RXRDY enum constant makes the code more self-documenting and easier to maintain.

Also applies to: 228-228

---

280-280: Appropriate use of SIO_CTRL_ERRRES

Using SIO_CTRL_ERRRES instead of a hardcoded value for error reset improves code readability.

src/mips/openbios/sio0/driver.c (8)

29-29: Good inclusion of the new SIO header

Adding the SIO header provides access to the new SIOPort structure, constants, and utility functions.

---

99-99: Improved readability with SIO constants

Replacing hardcoded bit values with SIO_CTRL_DTR and SIO_CTRL_PORTSEL makes the control register manipulation more understandable.

---

109-110: Better mask expression using SIO constants

Using SIO_CTRL_PORTSEL for the mask and SIO_CTRL_DTR for the control register makes the code's intent clearer.

---

116-117: Enhanced control register setup with constants

Using bit flag constants for the control register setup and status check improves code readability and maintainability.

---

121-123: Consistent error handling and status checking

The consistent use of SIO_CTRL_ERRRES for error reset and SIO_STAT_RXRDY/SIO_STAT_TXRDY for status checks throughout the file makes the code more uniform and easier to maintain.

Also applies to: 137-140, 157-160, 180-187, 205-208

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255-255: Improved mcHandler control register manipulation

Using the SIO constants for the control register in mcHandler enhances code readability.

---

319-321: Better SIO initialization in firstStageCardAction

Using SIO_CTRL_IR and calculating the baud rate rather than using magic numbers improves maintainability.

---

381-389: Cleaner SIO initialization in setupSIO0

The use of SIO constants for control register manipulation in setupSIO0 makes the initialization process more readable and maintainable.

src/mips/common/hardware/sio.h (6)

1-31: Well-structured header with proper licensing

The header includes the necessary MIT license and appropriate includes.

---

32-42: Good SIOPort structure definition

The SIOPort structure properly defines the memory layout for the serial port registers, which is essential for hardware interaction.

---

43-43: Appropriate use of volatile for hardware registers

The SIOS macro correctly uses volatile for accessing memory-mapped hardware registers, which is necessary to prevent compiler optimizations from affecting hardware interactions.

---

45-58: Excellent control register flag definitions

The enumeration for control register flags with descriptive comments greatly improves code readability and maintainability. Each flag's purpose is clearly documented.

---

60-71: Well-documented status register flags

The status register flag enumeration with clear comments makes it easy to understand the different status conditions that can be checked.

---

73-79: Efficient exchangeByte implementation

The inline exchangeByte function efficiently encapsulates the common pattern of reading from and writing to the SIO FIFO, while handling error reset and interrupt clearing. The always_inline attribute ensures optimal performance for this frequently called function.

✨ Finishing Touches

• 📝 Generate Docstrings

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[Copilot]

Copilot reviewed 6 out of 7 changed files in this pull request and generated no comments.

Files not reviewed (1)

• src/mips/openbios/Makefile: Language not supported

Comments suppressed due to low confidence (2)

src/mips/openbios/sio0/driver.c:101

• [nitpick] The busyloop delay values (e.g., 10, 20, 40) are used as magic numbers; consider defining named constants to improve readability and maintainability.

busyloop(10);

src/mips/openbios/sio0/card.c:110

• [nitpick] Consider removing or revising the informal comment ('durr?') to provide a clearer, more professional explanation of the rationale behind resetting g_skipErrorOnNewCard.

g_skipErrorOnNewCard = 0;  // durr?