diff options
Diffstat (limited to 'drivers/clk/clk.c')
-rw-r--r-- | drivers/clk/clk.c | 67 |
1 files changed, 52 insertions, 15 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index c83e8e5..de6b459 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1363,31 +1363,71 @@ 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; + bool migrated_enable = false; - /* migrate prepare and enable */ + /* migrate prepare */ if (clk->prepare_count) __clk_prepare(parent); - /* FIXME replace with clk_is_enabled(clk) someday */ flags = clk_enable_lock(); - if (clk->enable_count) + + /* migrate enable */ + if (clk->enable_count) { __clk_enable(parent); + migrated_enable = true; + } + + /* update the clk tree topology */ + clk_reparent(clk, parent); + clk_enable_unlock(flags); /* change clock input source */ 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(); - if (clk->enable_count) + if (ret) { + /* + * The error handling is tricky due to that we need to release + * the spinlock while issuing the .set_parent callback. This + * means the new parent might have been enabled/disabled in + * between, which must be considered when doing rollback. + */ + flags = clk_enable_lock(); + + clk_reparent(clk, old_parent); + + if (migrated_enable && clk->enable_count) { + __clk_disable(parent); + } else if (migrated_enable && (clk->enable_count == 0)) { + __clk_disable(old_parent); + } else if (!migrated_enable && clk->enable_count) { + __clk_disable(parent); + __clk_enable(old_parent); + } + + clk_enable_unlock(flags); + + if (clk->prepare_count) + __clk_unprepare(parent); + + return ret; + } + + /* clean up enable for old parent if migration was done */ + if (migrated_enable) { + flags = clk_enable_lock(); __clk_disable(old_parent); - clk_enable_unlock(flags); + clk_enable_unlock(flags); + } + /* clean up prepare for old parent if migration was done */ if (clk->prepare_count) __clk_unprepare(old_parent); - return ret; + /* update debugfs with new clk tree topology */ + clk_debug_reparent(clk, parent); + return 0; } /** @@ -1450,14 +1490,11 @@ int clk_set_parent(struct clk *clk, struct clk *parent) /* do the re-parent */ ret = __clk_set_parent(clk, parent, p_index); - /* propagate ABORT_RATE_CHANGE if .set_parent failed */ - if (ret) { + /* propagate rate recalculation accordingly */ + if (ret) __clk_recalc_rates(clk, ABORT_RATE_CHANGE); - goto out; - } - - /* propagate rate recalculation downstream */ - __clk_reparent(clk, parent); + else + __clk_recalc_rates(clk, POST_RATE_CHANGE); out: clk_prepare_unlock(); |