Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux

[linux-2.6-microblaze.git] / drivers / reset / core.c

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index a2df88e..34e89aa 100644 (file)
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -208,6 +208,39 @@ static int reset_control_array_reset(struct reset_control_array *resets)
        return 0;
 }
 
+static int reset_control_array_rearm(struct reset_control_array *resets)
+{
+       struct reset_control *rstc;
+       int i;
+
+       for (i = 0; i < resets->num_rstcs; i++) {
+               rstc = resets->rstc[i];
+
+               if (!rstc)
+                       continue;
+
+               if (WARN_ON(IS_ERR(rstc)))
+                       return -EINVAL;
+
+               if (rstc->shared) {
+                       if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
+                               return -EINVAL;
+               } else {
+                       if (!rstc->acquired)
+                               return -EPERM;
+               }
+       }
+
+       for (i = 0; i < resets->num_rstcs; i++) {
+               rstc = resets->rstc[i];
+
+               if (rstc && rstc->shared)
+                       WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);
+       }
+
+       return 0;
+}
+
 static int reset_control_array_assert(struct reset_control_array *resets)
 {
        int ret, i;
@@ -325,6 +358,46 @@ int reset_control_reset(struct reset_control *rstc)
 }
 EXPORT_SYMBOL_GPL(reset_control_reset);
 
+/**
+ * reset_control_rearm - allow shared reset line to be re-triggered"
+ * @rstc: reset controller
+ *
+ * On a shared reset line the actual reset pulse is only triggered once for the
+ * lifetime of the reset_control instance, except if this call is used.
+ *
+ * Calls to this function must be balanced with calls to reset_control_reset,
+ * a warning is thrown in case triggered_count ever dips below 0.
+ *
+ * Consumers must not use reset_control_(de)assert on shared reset lines when
+ * reset_control_reset or reset_control_rearm have been used.
+ *
+ * If rstc is NULL the function will just return 0.
+ */
+int reset_control_rearm(struct reset_control *rstc)
+{
+       if (!rstc)
+               return 0;
+
+       if (WARN_ON(IS_ERR(rstc)))
+               return -EINVAL;
+
+       if (reset_control_is_array(rstc))
+               return reset_control_array_rearm(rstc_to_array(rstc));
+
+       if (rstc->shared) {
+               if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
+                       return -EINVAL;
+
+               WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);
+       } else {
+               if (!rstc->acquired)
+                       return -EPERM;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(reset_control_rearm);
+
 /**
  * reset_control_assert - asserts the reset line
  * @rstc: reset controller