[patch 0/7] staging: speakup: introduce tty-based comms

[okash . khawaja]

Hi,

This patchset introduces a TTY-based way for the synths to communicate
with devices as an alternate for direct serial comms used by the synths
at the moment. It then migrates some of the synths to the TTY-based
comms. Synths migrated in this patchset are dummy, acntsa, bns and
txprt.

As such, this series is meant to start a discussion on the changes in the
first patch: "tty_port: allow a port to be opened with a tty that has no
file handle". This allows speakup to access tty port early on during boot,
making it possible to start emiting messages as early as possible. This is
demonstrated in patch 6, where it calls tty_open_by_driver, passing in NULL
for inode and filp params.

To wrap up, here is a summary of the patches that follow. Patch 1 enables
kernel access to TTY device. Patches 2 - 5 prepare the code to accomodate
TTY-based comms as an alternate to raw serial I/O for outputting data to
external device. Patch 6 builds upon the changes made in patch 1 and utilises
TTY-subsystem to communicate with external device - currently just over ttyS*
but with plans to expand it to other TTY devices soon. Finally, patch 7 does
actual migration of some of the simple synths from raw serial comms to TTY.

Okash