/*
* called in protocol stack drivers
* via the write function pointer
*/
long st_write(struct sk_buff *skb)
{
struct st_data_s *st_gdata;
long len;
st_kim_ref(&st_gdata, 0);
if (unlikely(skb == NULL || st_gdata == NULL
|| st_gdata->tty == NULL)) {
pr_err("data/tty unavailable to perform write");
return -EINVAL;
}
pr_debug("%d to be written", skb->len);
len = skb->len;
/*
* Refresh inactivity timeout for Power Management protection mechanism
* It will prevent from S3 sleeping for a while as it is very likely
* some incoming data will be received soon.
*/
wake_lock_timeout(&st_gdata->wake_lock,
ST_PM_PROTECT_INACTIVITY_TIMEOUT);
/* st_ll to decide where to enqueue the skb */
st_int_enqueue(st_gdata, skb);
/* wake up */
st_tx_wakeup(st_gdata);
/* return number of bytes written */
return len;
}
/*
* internal wakeup function
* called from either
* - TTY layer when write's finished
* - st_write (in context of the protocol stack)
*/
static void work_fn_write_wakeup(struct work_struct *work)
{
struct st_data_s *st_gdata = container_of(work, struct st_data_s,
work_write_wakeup);
st_tx_wakeup((void *)st_gdata);
}
/* wake-up function called in from the TTY layer
* inside the internal wakeup function will be called
*/
static void st_tty_wakeup(struct tty_struct *tty)
{
struct st_data_s *st_gdata = tty->disc_data;
pr_debug("%s ", __func__);
/* don't do an wakeup for now */
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
/* call our internal wakeup */
st_tx_wakeup((void *)st_gdata);
}
/**
* st_wakeup_ack - internal function for action when wake-up ack
* received
*/
static inline void st_wakeup_ack(struct st_data_s *st_gdata,
unsigned char cmd)
{
struct sk_buff *waiting_skb;
unsigned long flags = 0;
spin_lock_irqsave(&st_gdata->lock, flags);
/* de-Q from waitQ and Q in txQ now that the
* chip is awake
*/
while ((waiting_skb = skb_dequeue(&st_gdata->tx_waitq)))
skb_queue_tail(&st_gdata->txq, waiting_skb);
/* state forwarded to ST LL */
st_ll_sleep_state(st_gdata, (unsigned long)cmd);
spin_unlock_irqrestore(&st_gdata->lock, flags);
/* wake up to send the recently copied skbs from waitQ */
st_tx_wakeup(st_gdata);
}
/*
* called in protocol stack drivers
* via the write function pointer
*/
long st_write(struct sk_buff *skb)
{
struct st_data_s *st_gdata;
long len;
st_kim_ref(&st_gdata, 0);
if (unlikely(skb == NULL || st_gdata == NULL
|| st_gdata->tty == NULL)) {
pr_err("data/tty unavailable to perform write");
return -EINVAL;
}
pr_debug("%d to be written", skb->len);
len = skb->len;
/* st_ll to decide where to enqueue the skb */
st_int_enqueue(st_gdata, skb);
/* wake up */
st_tx_wakeup(st_gdata);
/* return number of bytes written */
return len;
}