kernel/uart: fix GetChar for PL011

Check RX buffer status when GetChar is called in no-wait mode.
This fixes an 'infinite keypress' issue that used to occur
after 16 keypresses.

Change-Id: I47762de387b07c4fed46cc192cd3b81fdabfb270
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4732
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

kernel/uart: Clean up uarts, make calling convention consistent

Change-Id: I36ef92ef13edb0b006344db74e9d1b3ae52e0127
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4327
Reviewed-by: X512 <danger_mail@list.ru>
Reviewed-by: Jessica Hamilton <jessica.l.hamilton@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>

kernel/uart: Refinements to irq and FIFO management

Style fixes to various parts of the system.

Signed-off-by: Adrien Destugues <pulkomandy@pulkomandy.tk>

This patch was never applied after GSoC 2012. Rebase the parts that
still apply so we can close the ticket.

Fixes #9490.

loader/u-boot: Use FDT serial info to create uart

* drop my fdt tests
* we have to call fdt parsing code *after* cpu_init (why?)
* pass fdt pointer to all FDT support calls to avoid confusion
once we get into the kernel land
* look for PL011 compatible uart and use it
* Add some saftey checks to serial putc code to avoid null*
* fdt_node_check_compatible returns 0 on success not 1
* fdt_get_device_reg needs to add the SOC base to the result
* fdt_get_device_reg might need to add the second range cell
instead of reg?

uart: Style Cleanup, no functional change

Attempt to factor out serial stuff

* introduce a DebugUART baseclass,
* rework 8250 and PL011 implementations from kallisti5 to inherit DebutUART,
* each arch should override the IO methods to access registers.
* on ARM registers are 32bit-aligned.
* U-Boot still works for the verdex target.
* rPi still compiles, needs testing.
* Still some more consolidation needed to allow runtime choice of the UART type (as read from FDT blobs for ex.).
* serial.cpp should probably mostly be made generic as well.
* didn't touch x86 or ppc yet.

loader/u-boot: Use FDT serial info to create uart

* drop my fdt tests
* we have to call fdt parsing code *after* cpu_init (why?)
* pass fdt pointer to all FDT support calls to avoid confusion
once we get into the kernel land
* look for PL011 compatible uart and use it
* Add some saftey checks to serial putc code to avoid null*
* fdt_node_check_compatible returns 0 on success not 1
* fdt_get_device_reg needs to add the SOC base to the result
* fdt_get_device_reg might need to add the second range cell
instead of reg?

uart: Style Cleanup, no functional change

Attempt to factor out serial stuff

* introduce a DebugUART baseclass,
* rework 8250 and PL011 implementations from kallisti5 to inherit DebutUART,
* each arch should override the IO methods to access registers.
* on ARM registers are 32bit-aligned.
* U-Boot still works for the verdex target.
* rPi still compiles, needs testing.
* Still some more consolidation needed to allow runtime choice of the UART type (as read from FDT blobs for ex.).
* serial.cpp should probably mostly be made generic as well.
* didn't touch x86 or ppc yet.