Having issues getting SPI MOSI and Clock output when using TFTDisplay

[anbutle]

I'm working on a prototype hardware device using a ili9341 compatible display, with a RP2350 micro controller. The lora radio and GPS modules are working fine, but I can't seem to get the display to draw anything. I've configured the display settings in the variant.h file:

#define TFT_DC 21
#define TFT_CS 17
#define TFT_SCLK 18
#define TFT_MOSI 19

And I can see the other related GPIOS (like CS and reset) associated with the SPI transactions for the display are working correctly and are visible via a logic analyzer.

But as you can see there is no output on the actual SPI bus for the CLK and MOSI signals when the display calls are made. I have validated that the hardware works in isolation by running a non-meshtastic based test firmware which writes to the display without issue on the same hardware.

I've only just started playing with Meshtastic and find that there are lots of configuration values which aren't clear so perhaps I am just missing something. I debugged all the way down into the LovyanGFX layer where I see that writeData is called so seemingly the device is trying to output SPI data. I wanted to see if anyone had any insight into what might be causing this issue where SPI data isn't being sent out on the bus.

[anbutle]

Following up after some more debugging.

I was unable to find a workaround by simply using the RP Pico SDK calls directly from main-rp2xx0.cpp to configure the various pins required for the TFT spi bus and gpios.

    gpio_set_function(TFT_SCLK, GPIO_FUNC_SPI);
    gpio_set_function(TFT_MOSI, GPIO_FUNC_SPI);

    gpio_init(TFT_CS);
    gpio_set_dir(TFT_CS, GPIO_OUT);
    gpio_put(TFT_CS, 1);

    // Setup the DC pin
    gpio_init(TFT_DC);
    gpio_set_dir(TFT_DC, GPIO_OUT);
    gpio_put(TFT_DC, 1);

    // Reset is acitve-low, so hold high until reset
    gpio_init(TFT_RST);
    gpio_set_dir(TFT_RST, GPIO_OUT);
    gpio_put(TFT_RST, 1);

I haven't had time to debug further, but I suspect there is a bug somewhere in either lgfx or the arduinopico stack related to setting these configurations. Potentially using some incorrect addresses based on the RP2040 MCUs. RP2350 support in meshtastic seems like a WIP currently as the existing 2350 based targets don't even compile on top of tree. Once I'm done with my current prototyping I'll add some PRs to resolve a number of these issues.