msm_serial_debugger: fiq-mode serial debugger support

This provides the ability to handle simple debug commands from
an fiq-context uart based debugger.
kmsg - dump printk log
pc - show current PC and mode
regs - show current registers

Other commands are handed off to an IRQ handler which calls the
kernel_debugger() routine provided by KERNEL_DEBUGGER_CORE.

Signed-off-by: Brian Swetland <swetland@google.com>

[ARM] msm_serial_debugger: Better interoperability with shared serial pins.

Introduce debug_enable, debugger will not echo back RX characters until
a CR is received. Other modules can turn off debug_enable via
msm_serial_debug_enable() interface.

Flush when doing TX in FIQ context.
Turn off interrupts and flush when doing TX in IRQ context.

Send a \r with every \n sent by the kernel debugger when processing
console messages.

Signed-off-by: Brian Swetland <swetland@google.com>

[ARM] msm_serial_debugger: irqs command to dump irq count

Signed-off-by: Brian Swetland <swetland@google.com>

[ARM] msm: msm_serial_debugger: Add irq status to 'irqs' fiq debug command.

Also clean up some alignment

Signed-off-by: Nick Pelly <npelly@google.com>

[ARM] msm: fiq_debugger: Add ability to enable / disable debugger at runtime

Signed-off-by: San Mehat <san@android.com>

[ARM] msm_serial_debugger: Support 19.2MHz clock on scorpion.

Signed-off-by: Arve Hjønnevåg <arve@android.com>

[ARM] msm_serial_debugger: Add wakeup irq and disable uart clock when idle

The serial debugger is now inactive by default so we can enter low power
modes. Hit enter twice to activate it for 5 seconds.

Signed-off-by: Arve Hjønnevåg <arve@android.com>

[ARM] msm_serial_debugger: Keep uart clock on when CONFIG_MSM_SERIAL_DEBUGGER_CONSOLE is enabled

Change-Id: I8c4e3c77d429a8f6fde068672d51e750e0f14c1b
Signed-off-by: Arve Hjønnevåg <arve@android.com>

msm_serial_debugger: fix to build without CONFIG_PREEMPT

Change-Id: I71e115a26142cccd809aa979dfa9541f842ae680

[ARM] msm: serial_debugger: move the clock disable to after we enable the fiq

If the uart fifo is not empty when we enable the fiq, the handler will try to
empty it and hang since the clock disabled prior to enabling the fiq.

Signed-off-by: Dima Zavin <dima@android.com>

[ARM] msm_serial_debugger: Add option to keep serial debugger active from boot.

If msm_serial_debugger.no_sleep=1 is added to the kernel command line, or
MSM_SERIAL_DEBUGGER_NO_SLEEP is selected in the config, the serial debugger
is activated on boot and stays active until it receives a sleep command.

Change-Id: Ibf84435af8203360ee808fd903dd6322cf5d9d17
Signed-off-by: Arve Hjønnevåg <arve@android.com>

[ARM] msm_serial_debugger: Fix startup when no_sleep is set

Change-Id: I7e55567d723e30d3e998d625aa7a53f896b55d61

[ARM] msm_serial_debugger: Add option to never disable wakeup IRQ.

This works better if the radio ignores the uart clock request while
power collapsed.

Change-Id: Ib0989e714e883b3667c9ecc4cfd1ebfe014a35df
Signed-off-by: Arve Hjønnevåg <arve@android.com>

[ARM] msm: Fix register dump in fiq debugger

Change-Id: Iff5cd48291c9b09aace30220c4229c157a7db1d0
Signed-off-by: Arve Hjønnevåg <arve@android.com>

[ARM] msm_serial_debugger: Add some debugger commands

Add allregs to dump registers for all modes.
Add bt to get a stackstrace.

Change-Id: Ia85e72b6c8243eba38a04cf4f6cc9cba5342a6de
Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: David Brown <davidb@codeaurora.org>