diff options
| -rw-r--r-- | drivers/clk/clk.c | 56 |
1 files changed, 36 insertions, 20 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 013a3c7fea5b..c83e8e543bab 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1332,15 +1332,10 @@ void __clk_reparent(struct clk *clk, struct clk *new_parent) __clk_recalc_rates(clk, POST_RATE_CHANGE); } -static int __clk_set_parent(struct clk *clk, struct clk *parent) +static u8 clk_fetch_parent_index(struct clk *clk, struct clk *parent) { - struct clk *old_parent; - unsigned long flags; - int ret = -EINVAL; u8 i; - old_parent = clk->parent; - if (!clk->parents) clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), GFP_KERNEL); @@ -1360,11 +1355,14 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent) } } - if (i == clk->num_parents) { - pr_debug("%s: clock %s is not a possible parent of clock %s\n", - __func__, parent->name, clk->name); - goto out; - } + return i; +} + +static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) +{ + unsigned long flags; + int ret = 0; + struct clk *old_parent = clk->parent; /* migrate prepare and enable */ if (clk->prepare_count) @@ -1377,7 +1375,8 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent) clk_enable_unlock(flags); /* change clock input source */ - ret = clk->ops->set_parent(clk->hw, i); + if (parent && clk->ops->set_parent) + ret = clk->ops->set_parent(clk->hw, p_index); /* clean up old prepare and enable */ flags = clk_enable_lock(); @@ -1388,7 +1387,6 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent) if (clk->prepare_count) __clk_unprepare(old_parent); -out: return ret; } @@ -1407,11 +1405,14 @@ out: int clk_set_parent(struct clk *clk, struct clk *parent) { int ret = 0; + u8 p_index = 0; + unsigned long p_rate = 0; if (!clk || !clk->ops) return -EINVAL; - if (!clk->ops->set_parent) + /* verify ops for for multi-parent clks */ + if ((clk->num_parents > 1) && (!clk->ops->set_parent)) return -ENOSYS; /* prevent racing with updates to the clock topology */ @@ -1420,19 +1421,34 @@ int clk_set_parent(struct clk *clk, struct clk *parent) if (clk->parent == parent) goto out; + /* check that we are allowed to re-parent if the clock is in use */ + if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { + ret = -EBUSY; + goto out; + } + + /* try finding the new parent index */ + if (parent) { + p_index = clk_fetch_parent_index(clk, parent); + p_rate = parent->rate; + if (p_index == clk->num_parents) { + pr_debug("%s: clk %s can not be parent of clk %s\n", + __func__, parent->name, clk->name); + ret = -EINVAL; + goto out; + } + } + /* propagate PRE_RATE_CHANGE notifications */ if (clk->notifier_count) - ret = __clk_speculate_rates(clk, parent->rate); + ret = __clk_speculate_rates(clk, p_rate); /* abort if a driver objects */ if (ret == NOTIFY_STOP) goto out; - /* only re-parent if the clock is not in use */ - if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) - ret = -EBUSY; - else - ret = __clk_set_parent(clk, parent); + /* do the re-parent */ + ret = __clk_set_parent(clk, parent, p_index); /* propagate ABORT_RATE_CHANGE if .set_parent failed */ if (ret) { |