Hi all, I'm working on enabling TWI3 (I2C3) on the Allwinner T113-S3 (sun8iw20) in U- Boot.
I set up the pinmux and clock for PG10/PG11 (function 3 for TWI3) using: sunxi_gpio_set_cfgpin(SUNXI_GPG(10), SUN8I_GPG_TWI3); sunxi_gpio_set_cfgpin(SUNXI_GPG(11), SUN8I_GPG_TWI3); clock_twi_onoff(3, 1); I also added the missing macro: #define SUN8I_GPG_TWI3 3 This works fine if I call it in board_late_init(), but if I set it earlier (e.g., i2c_init_board() or board_init()), the PG10/PG11 mux settings get overwritten or cleared later on. I verified the pinctrl register at 0x01C20824 (for PG10/PG11) is reset to 0xFFFFFFFF unless I reapply it in board_late_init(). Curiously, this does not happen to nearby ports like PG0–PG7 (0x01C20820), which remain intact. Is there some known U-Boot path that resets PG10/PG11 mux early on T113-S3? Best regards, Lukas Schmid
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