do some modification of printk

Signed-off-by: Le Min <lemin9538@gmail.com>
add a member flags to spin_lock_t

when do spin_lock and needed to save the irq
status using its flags to restore the value

Signed-off-by: Le Min <lemin9538@gmail.com>
change spin_lock to spin_lock_irqsave to avoid irq enable early

Signed-off-by: Le Min <lemin9538@gmail.com>
add suspend() to support suspend current process

Signed-off-by: Le Min <lemin9538@gmail.com>
rearch tty driver interface change get_char to get_chars

s3c2440 uart read ops using interrupt mode

Signed-off-by: Le Min <lemin9538@gmail.com>
add () to bit(nr) function to avoid marco error

Signed-off-by: Le Min <lemin9538@gmail.com>
separte subiirq to dedicated irq and allocate one irq num for them

Signed-off-by: Le Min <lemin9538@gmail.com>