diff options
Diffstat (limited to 'drivers/clk/clk.c')
| -rw-r--r-- | drivers/clk/clk.c | 100 |
1 files changed, 83 insertions, 17 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 0ebcf449778a..1fa4aaaa6d65 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -51,9 +51,13 @@ struct clk_core { struct clk_core **parents; u8 num_parents; u8 new_parent_index; + u8 safe_parent_index; unsigned long rate; unsigned long req_rate; + unsigned long old_rate; unsigned long new_rate; + unsigned long safe_freq; + struct clk_core *safe_parent; struct clk_core *new_parent; struct clk_core *new_child; unsigned long flags; @@ -1266,7 +1270,9 @@ out: static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate, struct clk_core *new_parent, u8 p_index) { - struct clk_core *child; + struct clk_core *child, *parent; + struct clk_hw *parent_hw; + unsigned long safe_freq = 0; core->new_rate = new_rate; core->new_parent = new_parent; @@ -1276,6 +1282,23 @@ static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate, if (new_parent && new_parent != core->parent) new_parent->new_child = core; + if (core->ops->get_safe_parent) { + parent_hw = core->ops->get_safe_parent(core->hw, &safe_freq); + if (parent_hw) { + parent = parent_hw->core; + p_index = clk_fetch_parent_index(core, parent); + core->safe_parent_index = p_index; + core->safe_parent = parent; + if (safe_freq) + core->safe_freq = safe_freq; + else + core->safe_freq = 0; + } + } else { + core->safe_parent = NULL; + core->safe_freq = 0; + } + hlist_for_each_entry(child, &core->children, child_node) { child->new_rate = clk_recalc(child, new_rate); clk_calc_subtree(child, child->new_rate, NULL, 0); @@ -1388,14 +1411,51 @@ static struct clk_core *clk_propagate_rate_change(struct clk_core *core, unsigned long event) { struct clk_core *child, *tmp_clk, *fail_clk = NULL; + struct clk_core *old_parent; int ret = NOTIFY_DONE; - if (core->rate == core->new_rate) + if (core->rate == core->new_rate && event != POST_RATE_CHANGE) return NULL; + switch (event) { + case PRE_RATE_CHANGE: + if (core->safe_parent) { + if (core->safe_freq) + core->ops->set_rate_and_parent(core->hw, + core->safe_freq, + core->safe_parent->rate, + core->safe_parent_index); + else + core->ops->set_parent(core->hw, + core->safe_parent_index); + } + core->old_rate = core->rate; + break; + case POST_RATE_CHANGE: + if (core->safe_parent) { + old_parent = __clk_set_parent_before(core, + core->new_parent); + if (core->ops->set_rate_and_parent) { + core->ops->set_rate_and_parent(core->hw, + core->new_rate, + core->new_parent ? + core->new_parent->rate : 0, + core->new_parent_index); + } else if (core->ops->set_parent) { + core->ops->set_parent(core->hw, + core->new_parent_index); + } + __clk_set_parent_after(core, core->new_parent, + old_parent); + } + break; + } + if (core->notifier_count) { - ret = __clk_notify(core, event, core->rate, core->new_rate); - if (ret & NOTIFY_STOP_MASK) + if (event != POST_RATE_CHANGE || core->old_rate != core->rate) + ret = __clk_notify(core, event, core->old_rate, + core->new_rate); + if (ret & NOTIFY_STOP_MASK && event != POST_RATE_CHANGE) fail_clk = core; } @@ -1422,23 +1482,19 @@ static struct clk_core *clk_propagate_rate_change(struct clk_core *core, * walk down a subtree and set the new rates notifying the rate * change on the way */ -static void clk_change_rate(struct clk_core *core) +static void +clk_change_rate(struct clk_core *core, unsigned long best_parent_rate) { struct clk_core *child; struct hlist_node *tmp; unsigned long old_rate; - unsigned long best_parent_rate = 0; bool skip_set_rate = false; struct clk_core *old_parent; old_rate = core->rate; - if (core->new_parent) - best_parent_rate = core->new_parent->rate; - else if (core->parent) - best_parent_rate = core->parent->rate; - - if (core->new_parent && core->new_parent != core->parent) { + if (core->new_parent && core->new_parent != core->parent && + !core->safe_parent) { old_parent = __clk_set_parent_before(core, core->new_parent); trace_clk_set_parent(core, core->new_parent); @@ -1463,6 +1519,7 @@ static void clk_change_rate(struct clk_core *core) trace_clk_set_rate_complete(core, core->new_rate); core->rate = clk_recalc(core, best_parent_rate); + core->rate = core->new_rate; if (core->notifier_count && old_rate != core->rate) __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate); @@ -1478,12 +1535,13 @@ static void clk_change_rate(struct clk_core *core) /* Skip children who will be reparented to another clock */ if (child->new_parent && child->new_parent != core) continue; - clk_change_rate(child); + if (child->new_rate != child->rate) + clk_change_rate(child, core->new_rate); } - /* handle the new child who might not be in core->children yet */ - if (core->new_child) - clk_change_rate(core->new_child); + /* handle the new child who might not be in clk->children yet */ + if (core->new_child && core->new_child->new_rate != core->new_child->rate) + clk_change_rate(core->new_child, core->new_rate); } static int clk_core_set_rate_nolock(struct clk_core *core, @@ -1492,6 +1550,7 @@ static int clk_core_set_rate_nolock(struct clk_core *core, struct clk_core *top, *fail_clk; unsigned long rate = req_rate; int ret = 0; + unsigned long parent_rate; if (!core) return 0; @@ -1517,11 +1576,18 @@ static int clk_core_set_rate_nolock(struct clk_core *core, return -EBUSY; } + if (top->parent) + parent_rate = top->parent->rate; + else + parent_rate = 0; + /* change the rates */ - clk_change_rate(top); + clk_change_rate(top, parent_rate); core->req_rate = req_rate; + clk_propagate_rate_change(top, POST_RATE_CHANGE); + return ret; } |