fix(PeriphDrivers): Fix UART clock source selection for MAX32650/60/65/66

[anilozrenk]

Description

Fixes UART clock source selection across legacy MAX32 microcontrollers and updates the Zephyr wrapper to properly support IBRO (7MHz) clock selection.

Changes

PeriphDrivers

• uart_me10.c (MAX32650) & uart_me14.c (MAX32665/66): Fixed MXC_UART_SetClockSource() to:

  • Validate UART instance before proceeding
  • Enable HIRC8 clock source when using PCLK
  • Correct the inverted usePCLK parameter passed to MXC_UART_RevA_SetClockSource()
  • Enable HIRC8 clock when needed
  • Fix inverted usePCLK parameter

• uart_me11.c (MAX32660): Simplified MXC_UART_SetClockSource() to return E_NO_ERROR since MAX32660 only supports PCLK (no alternative clock source)

• uart_reva.c: Improved clock source switching logic:

  • Added baud rate validation against the selected clock source's maximum capability
  • Falls back to 115200 baud if current baud rate exceeds clock limits
  • Improved error handling for MXC_UART_SetFrequency() calls

Zephyr Wrapper

• wrap_max32_uart.h: Updated Wrap_MXC_UART_SetClockSource() to:
  • Add proper SOC-specific handling for MAX32660 (PCLK only)
  • Enable IBRO and PCLK clock source selection for MAX32650/65/66
  • Call the underlying MXC_UART_SetClockSource() for supported clock sources

Affected Devices

• MAX32650
• MAX32660
• MAX32665/MAX32666

[ttmut]

/clang-format-run

[ttmut]

What happens if we do not fall back to 115200bps? How is the behavior in other parts?

[anilozrenk]

At reset, when baud registers set 0, GetFrequency will return peripheralClock/3. And maximum baudrate can be pclk/8. This part should only run at reset. if baudrate set once. It can getFrequecy properly. Eg. in zephyr uart_max32 driver tries to set clock first and then set baudrate, it fails. What do you suggest? @ttmut

[ttmut]

I see the issue.

Well at least set the baudrate to PeripheralClock / 8 so that it is somewhat consistent with the documentation.

The baud rate generator will automatically be reconfigured to the closest possible baud rate.

[ttmut]

I see the issue.

Well at least set the baudrate to PeripheralClock / 8 so that it is somewhat consistent with the documentation.

The baud rate generator will automatically be reconfigured to the closest possible baud rate.