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  • Andre Przywara's avatar
    drivers: PL011: add support for the ARM SBSA generic UART · 0dd1e247
    Andre Przywara authored
    
    
    The ARM Server Base System Architecture[1] document describes a
    generic UART which is a subset of the PL011 UART.
    It lacks DMA support, baud rate control and modem status line
    control, among other things.
    The idea is to move the UART initialization and setup into the
    firmware (which does this job today already) and let the kernel just
    use the UART for sending and receiving characters.
    
    We use the recent refactoring to build a new struct uart_ops
    variable which points to some new functions avoiding access to the
    missing registers. We reuse as much existing PL011 code as possible.
    
    In contrast to the PL011 the SBSA UART does not define any AMBA or
    PrimeCell relations, so we go with a pretty generic probe function
    which only uses platform device functions.
    A DT binding is provided with this patch, ACPI support is added in a
    separate one.
    
    Signed-off-by: default avatarAndre Przywara <andre.przywara@arm.com>
    Tested-by: default avatarMark Langsdorf <mlangsdo@redhat.com>
    Tested-by: default avatarNaresh Bhat <nbhat@cavium.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    0dd1e247