/* called with callback_lock held */
static int
srmcons_do_write(struct tty_port *port, const char *buf, int count)
{
static char str_cr[1] = "\r";
long c, remaining = count;
srmcons_result result;
char *cur;
int need_cr;
for (cur = (char *)buf; remaining > 0; ) {
need_cr = 0;
/*
* Break it up into reasonable size chunks to allow a chance
* for input to get in
*/
for (c = 0; c < min_t(long, 128L, remaining) && !need_cr; c++)
if (cur[c] == '\n')
need_cr = 1;
while (c > 0) {
result.as_long = callback_puts(0, cur, c);
c -= result.bits.c;
remaining -= result.bits.c;
cur += result.bits.c;
/*
* Check for pending input iff a tty port was provided
*/
if (port)
srmcons_do_receive_chars(port);
}
while (need_cr) {
result.as_long = callback_puts(0, str_cr, 1);
if (result.bits.c > 0)
need_cr = 0;
}
}
return count;
}
static void
srmcons_receive_chars(unsigned long data)
{
struct srmcons_private *srmconsp = (struct srmcons_private *)data;
struct tty_port *port = &srmconsp->port;
unsigned long flags;
int incr = 10;
local_irq_save(flags);
if (spin_trylock(&srmcons_callback_lock)) {
if (!srmcons_do_receive_chars(port))
incr = 100;
spin_unlock(&srmcons_callback_lock);
}
spin_lock(&port->lock);
if (port->tty)
mod_timer(&srmconsp->timer, jiffies + incr);
spin_unlock(&port->lock);
local_irq_restore(flags);
}
static void
srmcons_receive_chars(unsigned long data)
{
struct srmcons_private *srmconsp = (struct srmcons_private *)data;
unsigned long flags;
int incr = 10;
local_irq_save(flags);
if (spin_trylock(&srmcons_callback_lock)) {
if (!srmcons_do_receive_chars(srmconsp->tty))
incr = 100;
spin_unlock(&srmcons_callback_lock);
}
spin_lock(&srmconsp->lock);
if (srmconsp->tty) {
srmconsp->timer.expires = jiffies + incr;
add_timer(&srmconsp->timer);
}
spin_unlock(&srmconsp->lock);
local_irq_restore(flags);
}