ptp: introduce programmable pins.

This patch adds a pair of new ioctls to the PTP Hardware Clock device
interface. Using the ioctls, user space programs can query each pin to
find out its current function and also reprogram a different function
if desired.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index df03f2e30ad9..b114a84c63c7 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -48,6 +48,7 @@ struct ptp_clock {
         long dialed_frequency; /* remembers the frequency adjustment */
         struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
         struct mutex tsevq_mux; /* one process at a time reading the fifo */
+        struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
         wait_queue_head_t tsev_wq;
         int defunct; /* tells readers to go away when clock is being removed */
 };
@@ -69,6 +70,10 @@ static inline int queue_cnt(struct timestamp_event_queue *q)
  * see ptp_chardev.c
  */
 
+/* caller must hold pincfg_mux */
+int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
+                    enum ptp_pin_function func, unsigned int chan);
+
 long ptp_ioctl(struct posix_clock *pc,
                unsigned int cmd, unsigned long arg);