Simon,
Now I am seeing driver/serial/serial_tegra.c
U_BOOT_DRIVER(serial_ns16550) = { .name = "serial_tegra20", .id = UCLASS_SERIAL, .of_match = tegra_serial_ids, .ofdata_to_platdata = tegra_serial_ofdata_to_platdata, .platdata_auto_alloc_size = sizeof(struct ns16550_platdata), .priv_auto_alloc_size = sizeof(struct NS16550), .probe = ns16550_serial_probe, .ops = &ns16550_serial_ops,
You require sizeof(struct NS16550) (= about 30~ 40 bytes) for .priv_auto_alloc_size.
Seems strange.
It looks like the private date is used as the base address of the hardware
Here,
struct NS16550 *const com_port = dev_get_priv(dev);
If the hardware register has 0x10000 width, do we need to allocation 0x10000 memory for .priv data?
I think 4 byte (or 8 byte on 64bit architectures) is enough to store the base address.
It looks like the memory is allocated for .priv in device_probe() function, but I could not find where .priv is set for pointing to the base address.
Perhaps I am not understanding well yet, but I'm still not convinced how it is working.
Best Regards Masahiro Yamada