IB/ipath: Support blinking LEDs with an led_override file

When we want to find an InfiniPath HCA in a rack of nodes, it is often
expeditious to blink the status LEDs via a userspace /sys file.

A write-only led_override "file" is published per device. Writes to
this file are interpreted as (string form) numbers, and the resulting
value sent to ipath_set_led_override(). The upper eight bits are
interpretted as a 4.4 fixed-point "frequency in Hertz", and the bottom
two 4-bit values are alternately (D0..3, then D4..7) used by the
board-specific LED-setting function to override the normal state.

Signed-off-by: Michael Albaugh <michael.albaugh@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_iba6110.c b/drivers/infiniband/hw/ipath/ipath_iba6110.c
index ba73dd0a06cd..4372c6c50ff6 100644
--- a/drivers/infiniband/hw/ipath/ipath_iba6110.c
+++ b/drivers/infiniband/hw/ipath/ipath_iba6110.c
@@ -1065,6 +1065,16 @@ static void ipath_setup_ht_setextled(struct ipath_devdata *dd,
         if (ipath_diag_inuse)
                 return;
 
+        /* Allow override of LED display for, e.g. Locating system in rack */
+        if (dd->ipath_led_override) {
+                ltst = (dd->ipath_led_override & IPATH_LED_PHYS)
+                        ? INFINIPATH_IBCS_LT_STATE_LINKUP
+                        : INFINIPATH_IBCS_LT_STATE_DISABLED;
+                lst = (dd->ipath_led_override & IPATH_LED_LOG)
+                        ? INFINIPATH_IBCS_L_STATE_ACTIVE
+                        : INFINIPATH_IBCS_L_STATE_DOWN;
+        }
+
         /*
          * start by setting both LED control bits to off, then turn
          * on the appropriate bit(s).