esp32s3 t-display-s3: emulate external pullups

Emulate the external pullup resistors on
the GPIO0/GPIO14 buttons of the T-Display-S3.

On the physical t-display-s3, this works:

pin0 = Pin(0, Pin.IN)
pin0.value() # returns 1 (as it should because it's pulled high by an external resistor)

But on the emulator, the same code behaves differently:

pin0 = Pin(0, Pin.IN)
pin0.value() # returns 0 because external pullups weren't emulated

Internal pullups have been implemented already in commit cbb15d7
at https://github.com/a159x36/qemu/pull/2/changes so this works:

pin0 = Pin(0, Pin.IN, Pin.PULL_UP)
pin0.value() # returns 1 when internal pullups are supported

Obviously, the more the emulator mimicks the real hardware, the better,
so this is another step in the right direction.

Author: ThomasFarstrike

hw/gpio/esp32s3_gpio.c

@@ -992,6 +992,8 @@ static void ESP32S3_GPIO_reset(Object *dev, ResetType type) {
         if(reset_type==4) {
             if(i<32) s->gpio_enable=1<<i; else s->gpio_enable1=1<<(i-32);
         }
+        // Emulate the external pullup resistors on the GPIO0/GPIO14 buttons of the T-Display-S3
+        if (i == 0 || i == 14) v = FIELD_DP32(v, IO_MUX, FUN_WPU, 1);
         s->iomux_regs[i+1]=v;
     }
     for (int i = 0; i < N_GPIOS; i++) {