As ESP32 has 2 I2C interfaces and BMP180 is a I2C sensor, the criterias to use BMP180 in I2C0 or I2C1 are:
1- First, bring-up routines search for BMP180 in I2C0.
If BMP180 is found in I2C0, then /dev/press0 is created.
2- If BMP180 cannot be registered in I2C0, bring-up routines search for it in I2C1.
If BMP180 is found in I2C1, then /dev/press0 is created.
It means only one BMP180 could be suported in Nuttx. In my tests I've observed
that BMP180 example application doesn't seem to work with /dev/press1 BMP180 device,
therefore even BMP180 is found in I2C1, it'll be registered as /dev/press0 device.
It was missing and it wasn't possible to enable I2C (0 and/or 1)
before this fix.
To sum up, this fix implements a I2C register function in ESP32
bring-up routines (esp32_bringup.c) and call if for I2C0 and/or
I2C1 during ESP32 bringup (these function callings are conditioned
by CONFIG_ESP32_I2C (to check if I2C support has been configured),
CONFIG_ESP32_I2C0 (to check if I2C0 support has been configured)
and CONFIG_ESP32_I2C1 (to check if I2C1 support has been configured).
Once this fix is implemented, /dev/i2c0 and/or /dev/i2c1 interfaces
become available and work fine.
