diff options
Diffstat (limited to 'drivers/tty/bfin_jtag_comm.c')
-rw-r--r-- | drivers/tty/bfin_jtag_comm.c | 44 |
1 files changed, 22 insertions, 22 deletions
diff --git a/drivers/tty/bfin_jtag_comm.c b/drivers/tty/bfin_jtag_comm.c index 946f799861f5..61fc74fe1747 100644 --- a/drivers/tty/bfin_jtag_comm.c +++ b/drivers/tty/bfin_jtag_comm.c @@ -62,9 +62,7 @@ static inline uint32_t bfin_write_emudat_chars(char a, char b, char c, char d) static struct tty_driver *bfin_jc_driver; static struct task_struct *bfin_jc_kthread; -static struct tty_struct * volatile bfin_jc_tty; -static unsigned long bfin_jc_count; -static DEFINE_MUTEX(bfin_jc_tty_mutex); +static struct tty_port port; static volatile struct circ_buf bfin_jc_write_buf; static int @@ -73,18 +71,21 @@ bfin_jc_emudat_manager(void *arg) uint32_t inbound_len = 0, outbound_len = 0; while (!kthread_should_stop()) { + struct tty_struct *tty = tty_port_tty_get(&port); /* no one left to give data to, so sleep */ - if (bfin_jc_tty == NULL && circ_empty(&bfin_jc_write_buf)) { + if (tty == NULL && circ_empty(&bfin_jc_write_buf)) { pr_debug("waiting for readers\n"); __set_current_state(TASK_UNINTERRUPTIBLE); schedule(); __set_current_state(TASK_RUNNING); + continue; } /* no data available, so just chill */ if (!(bfin_read_DBGSTAT() & EMUDIF) && circ_empty(&bfin_jc_write_buf)) { pr_debug("waiting for data (in_len = %i) (circ: %i %i)\n", inbound_len, bfin_jc_write_buf.tail, bfin_jc_write_buf.head); + tty_kref_put(tty); if (inbound_len) schedule(); else @@ -94,9 +95,6 @@ bfin_jc_emudat_manager(void *arg) /* if incoming data is ready, eat it */ if (bfin_read_DBGSTAT() & EMUDIF) { - struct tty_struct *tty; - mutex_lock(&bfin_jc_tty_mutex); - tty = (struct tty_struct *)bfin_jc_tty; if (tty != NULL) { uint32_t emudat = bfin_read_emudat(); if (inbound_len == 0) { @@ -110,7 +108,6 @@ bfin_jc_emudat_manager(void *arg) tty_flip_buffer_push(tty); } } - mutex_unlock(&bfin_jc_tty_mutex); } /* if outgoing data is ready, post it */ @@ -120,7 +117,6 @@ bfin_jc_emudat_manager(void *arg) bfin_write_emudat(outbound_len); pr_debug("outgoing length: 0x%08x\n", outbound_len); } else { - struct tty_struct *tty; int tail = bfin_jc_write_buf.tail; size_t ate = (4 <= outbound_len ? 4 : outbound_len); uint32_t emudat = @@ -132,14 +128,12 @@ bfin_jc_emudat_manager(void *arg) ); bfin_jc_write_buf.tail += ate; outbound_len -= ate; - mutex_lock(&bfin_jc_tty_mutex); - tty = (struct tty_struct *)bfin_jc_tty; if (tty) tty_wakeup(tty); - mutex_unlock(&bfin_jc_tty_mutex); pr_debug(" outgoing data: 0x%08x (pushing %zu)\n", emudat, ate); } } + tty_kref_put(tty); } __set_current_state(TASK_RUNNING); @@ -149,24 +143,28 @@ bfin_jc_emudat_manager(void *arg) static int bfin_jc_open(struct tty_struct *tty, struct file *filp) { - mutex_lock(&bfin_jc_tty_mutex); - pr_debug("open %lu\n", bfin_jc_count); - ++bfin_jc_count; - bfin_jc_tty = tty; + unsigned long flags; + + spin_lock_irqsave(&port.lock, flags); + port.count++; + spin_unlock_irqrestore(&port.lock, flags); + tty_port_tty_set(&port, tty); wake_up_process(bfin_jc_kthread); - mutex_unlock(&bfin_jc_tty_mutex); return 0; } static void bfin_jc_close(struct tty_struct *tty, struct file *filp) { - mutex_lock(&bfin_jc_tty_mutex); - pr_debug("close %lu\n", bfin_jc_count); - if (--bfin_jc_count == 0) - bfin_jc_tty = NULL; + unsigned long flags; + bool last; + + spin_lock_irqsave(&port.lock, flags); + last = --port.count == 0; + spin_unlock_irqrestore(&port.lock, flags); + if (last) + tty_port_tty_set(&port, NULL); wake_up_process(bfin_jc_kthread); - mutex_unlock(&bfin_jc_tty_mutex); } /* XXX: we dont handle the put_char() case where we must handle count = 1 */ @@ -242,6 +240,8 @@ static int __init bfin_jc_init(void) { int ret; + tty_port_init(&port); + bfin_jc_kthread = kthread_create(bfin_jc_emudat_manager, NULL, DRV_NAME); if (IS_ERR(bfin_jc_kthread)) return PTR_ERR(bfin_jc_kthread); |