• Dirk Brandewie's avatar
    ce4100: Add errata fixes for UART on CE4100 · 5ec6960f
    Dirk Brandewie authored
    This patch enables the UART on the CE4100. The UART has a couple of
    issues that need to be worked around. First the UART is mostly PC
    compatible except that it is clocked eight times faster than a
    standard PC so the default configuration provided in
    arch/x86/include/asm/serial.h needs to be overridden. Second the TX
    interrupt may not be set correctly all the time. Lastly accessing the
    UART via I/O space for early_prink() hangs the chip when the IOAPIC is
    enabled.
    
    A custom mem_serial_in() is provided to work around the TX interrupt
    issue. The configuration issues are dealt with in the call back
    registered with the 8250 driver via serial8250_set_isa_configurator()
    Signed-off-by: default avatarDirk Brandewie <dirk.brandewie@gmail.com>
    LKML-Reference: <1290436128-17958-1-git-send-email-dirk.brandewie@gmail.com>
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    5ec6960f
ce4100.c 3.43 KB