ability to read GPIO holder status (IDFGH-14018)

[bryghtlabs-richard]

Is your feature request related to a problem?

I need the ability to read the GPIO holder status per pin, so that I can discover the state of different peripherals after a restart.

Describe the solution you'd like.

I'd like a nice ESP-IDF GPIO interface to take a GPIO number and receive a boolean value if the pin-holder was enabled or disabled.

Describe alternatives you've considered.

No response

Additional context.

No response

[bryghtlabs-richard]

There is a related function, gpio_ll_is_digital_io_hold(), but nothing at the gpio.h level.

[songruo]

Hi @bryghtlabs-richard,

From your PR description, I get your scenario is you need to hold the SPI LCD CS line during a restart (core reset), is that correct? Though you have held the CS pad before restart, after the system restarts, all the signal connection information will still get lost, so you will still have to re-configure the pin (assuming you are using esp_lcd_new_panel_io_spi()), and then eventually release the hold.

Is there any reason why you don't want to call esp_lcd_new_panel_io_spi() after the restart?

[bryghtlabs-richard]

Hi @songruo ,

It's close but not exactly what you described. I'm using esp_lcd_new_panel_io_spi() for every startup.

If the CS/RST pins were held with pin-holders, then I know an earlier software run has already configured the display, so I need to avoid calling esp_lcd_panel_reset() and avoid initial startup register scripts to prevent displaying corruption to user.

If the CS/RST were not held with pin-holders, then the display needs to be fully booted, with esp_lcd_panel_reset() and initial startup register scripts and delays.

[songruo]

@bryghtlabs-richard Do you think checking the chip reset reason with esp_rom_get_reset_reason() can also achieve the purpose?