diff options
Diffstat (limited to 'drivers/clk/clk.c')
| -rw-r--r-- | drivers/clk/clk.c | 221 |
1 files changed, 80 insertions, 141 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index b4db67a446c8..fb74dc1f7520 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -350,13 +350,12 @@ static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core, { if (!core || index >= core->num_parents) return NULL; - else if (!core->parents) - return clk_core_lookup(core->parent_names[index]); - else if (!core->parents[index]) - return core->parents[index] = - clk_core_lookup(core->parent_names[index]); - else - return core->parents[index]; + + if (!core->parents[index]) + core->parents[index] = + clk_core_lookup(core->parent_names[index]); + + return core->parents[index]; } struct clk_hw * @@ -386,7 +385,7 @@ static unsigned long clk_core_get_rate_nolock(struct clk_core *core) ret = core->rate; - if (core->flags & CLK_IS_ROOT) + if (!core->num_parents) goto out; if (!core->parent) @@ -1067,30 +1066,12 @@ static int clk_fetch_parent_index(struct clk_core *core, { int i; - if (!core->parents) { - core->parents = kcalloc(core->num_parents, - sizeof(struct clk *), GFP_KERNEL); - if (!core->parents) - return -ENOMEM; - } - - /* - * find index of new parent clock using cached parent ptrs, - * or if not yet cached, use string name comparison and cache - * them now to avoid future calls to clk_core_lookup. - */ - for (i = 0; i < core->num_parents; i++) { - if (core->parents[i] == parent) - return i; - - if (core->parents[i]) - continue; + if (!parent) + return -EINVAL; - if (!strcmp(core->parent_names[i], parent->name)) { - core->parents[i] = clk_core_lookup(parent->name); + for (i = 0; i < core->num_parents; i++) + if (clk_core_get_parent_by_index(core, i) == parent) return i; - } - } return -EINVAL; } @@ -1677,56 +1658,14 @@ struct clk *clk_get_parent(struct clk *clk) } EXPORT_SYMBOL_GPL(clk_get_parent); -/* - * .get_parent is mandatory for clocks with multiple possible parents. It is - * optional for single-parent clocks. Always call .get_parent if it is - * available and WARN if it is missing for multi-parent clocks. - * - * For single-parent clocks without .get_parent, first check to see if the - * .parents array exists, and if so use it to avoid an expensive tree - * traversal. If .parents does not exist then walk the tree. - */ static struct clk_core *__clk_init_parent(struct clk_core *core) { - struct clk_core *ret = NULL; - u8 index; + u8 index = 0; - /* handle the trivial cases */ + if (core->num_parents > 1 && core->ops->get_parent) + index = core->ops->get_parent(core->hw); - if (!core->num_parents) - goto out; - - if (core->num_parents == 1) { - if (IS_ERR_OR_NULL(core->parent)) - core->parent = clk_core_lookup(core->parent_names[0]); - ret = core->parent; - goto out; - } - - if (!core->ops->get_parent) { - WARN(!core->ops->get_parent, - "%s: multi-parent clocks must implement .get_parent\n", - __func__); - goto out; - } - - /* - * Do our best to cache parent clocks in core->parents. This prevents - * unnecessary and expensive lookups. We don't set core->parent here; - * that is done by the calling function. - */ - - index = core->ops->get_parent(core->hw); - - if (!core->parents) - core->parents = - kcalloc(core->num_parents, sizeof(struct clk *), - GFP_KERNEL); - - ret = clk_core_get_parent_by_index(core, index); - -out: - return ret; + return clk_core_get_parent_by_index(core, index); } static void clk_core_reparent(struct clk_core *core, @@ -1809,13 +1748,13 @@ static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent) /* try finding the new parent index */ if (parent) { p_index = clk_fetch_parent_index(core, parent); - p_rate = parent->rate; if (p_index < 0) { pr_debug("%s: clk %s can not be parent of clk %s\n", __func__, parent->name, core->name); ret = p_index; goto out; } + p_rate = parent->rate; } /* propagate PRE_RATE_CHANGE notifications */ @@ -1902,6 +1841,10 @@ int clk_set_phase(struct clk *clk, int degrees) clk_prepare_lock(); + /* bail early if nothing to do */ + if (degrees == clk->core->phase) + goto out; + trace_clk_set_phase(clk->core, degrees); if (clk->core->ops->set_phase) @@ -1912,6 +1855,7 @@ int clk_set_phase(struct clk *clk, int degrees) if (!ret) clk->core->phase = degrees; +out: clk_prepare_unlock(); return ret; @@ -2218,7 +2162,7 @@ unlock: * * Dynamically removes a clk and all its child nodes from the * debugfs clk directory if clk->dentry points to debugfs created by - * clk_debug_register in __clk_init. + * clk_debug_register in __clk_core_init. */ static void clk_debug_unregister(struct clk_core *core) { @@ -2303,26 +2247,22 @@ static inline void clk_debug_unregister(struct clk_core *core) #endif /** - * __clk_init - initialize the data structures in a struct clk - * @dev: device initializing this clk, placeholder for now - * @clk: clk being initialized + * __clk_core_init - initialize the data structures in a struct clk_core + * @core: clk_core being initialized * * Initializes the lists in struct clk_core, queries the hardware for the * parent and rate and sets them both. */ -static int __clk_init(struct device *dev, struct clk *clk_user) +static int __clk_core_init(struct clk_core *core) { int i, ret = 0; struct clk_core *orphan; struct hlist_node *tmp2; - struct clk_core *core; unsigned long rate; - if (!clk_user) + if (!core) return -EINVAL; - core = clk_user->core; - clk_prepare_lock(); /* check to see if a clock with this name is already registered */ @@ -2337,22 +2277,29 @@ static int __clk_init(struct device *dev, struct clk *clk_user) if (core->ops->set_rate && !((core->ops->round_rate || core->ops->determine_rate) && core->ops->recalc_rate)) { - pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n", - __func__, core->name); + pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n", + __func__, core->name); ret = -EINVAL; goto out; } if (core->ops->set_parent && !core->ops->get_parent) { - pr_warning("%s: %s must implement .get_parent & .set_parent\n", - __func__, core->name); + pr_err("%s: %s must implement .get_parent & .set_parent\n", + __func__, core->name); + ret = -EINVAL; + goto out; + } + + if (core->num_parents > 1 && !core->ops->get_parent) { + pr_err("%s: %s must implement .get_parent as it has multi parents\n", + __func__, core->name); ret = -EINVAL; goto out; } if (core->ops->set_rate_and_parent && !(core->ops->set_parent && core->ops->set_rate)) { - pr_warn("%s: %s must implement .set_parent & .set_rate\n", + pr_err("%s: %s must implement .set_parent & .set_rate\n", __func__, core->name); ret = -EINVAL; goto out; @@ -2364,37 +2311,12 @@ static int __clk_init(struct device *dev, struct clk *clk_user) "%s: invalid NULL in %s's .parent_names\n", __func__, core->name); - /* - * Allocate an array of struct clk *'s to avoid unnecessary string - * look-ups of clk's possible parents. This can fail for clocks passed - * in to clk_init during early boot; thus any access to core->parents[] - * must always check for a NULL pointer and try to populate it if - * necessary. - * - * If core->parents is not NULL we skip this entire block. This allows - * for clock drivers to statically initialize core->parents. - */ - if (core->num_parents > 1 && !core->parents) { - core->parents = kcalloc(core->num_parents, sizeof(struct clk *), - GFP_KERNEL); - /* - * clk_core_lookup returns NULL for parents that have not been - * clk_init'd; thus any access to clk->parents[] must check - * for a NULL pointer. We can always perform lazy lookups for - * missing parents later on. - */ - if (core->parents) - for (i = 0; i < core->num_parents; i++) - core->parents[i] = - clk_core_lookup(core->parent_names[i]); - } - core->parent = __clk_init_parent(core); /* - * Populate core->parent if parent has already been __clk_init'd. If - * parent has not yet been __clk_init'd then place clk in the orphan - * list. If clk has set the CLK_IS_ROOT flag then place it in the root + * Populate core->parent if parent has already been clk_core_init'd. If + * parent has not yet been clk_core_init'd then place clk in the orphan + * list. If clk doesn't have any parents then place it in the root * clk list. * * Every time a new clk is clk_init'd then we walk the list of orphan @@ -2405,7 +2327,7 @@ static int __clk_init(struct device *dev, struct clk *clk_user) hlist_add_head(&core->child_node, &core->parent->children); core->orphan = core->parent->orphan; - } else if (core->flags & CLK_IS_ROOT) { + } else if (!core->num_parents) { hlist_add_head(&core->child_node, &clk_root_list); core->orphan = false; } else { @@ -2454,24 +2376,15 @@ static int __clk_init(struct device *dev, struct clk *clk_user) core->rate = core->req_rate = rate; /* - * walk the list of orphan clocks and reparent any that are children of - * this clock + * walk the list of orphan clocks and reparent any that newly finds a + * parent. */ hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { - if (orphan->num_parents && orphan->ops->get_parent) { - i = orphan->ops->get_parent(orphan->hw); - if (i >= 0 && i < orphan->num_parents && - !strcmp(core->name, orphan->parent_names[i])) - clk_core_reparent(orphan, core); - continue; - } + struct clk_core *parent = __clk_init_parent(orphan); - for (i = 0; i < orphan->num_parents; i++) - if (!strcmp(core->name, orphan->parent_names[i])) { - clk_core_reparent(orphan, core); - break; - } - } + if (parent) + clk_core_reparent(orphan, parent); + } /* * optional platform-specific magic @@ -2585,21 +2498,31 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) } } + /* avoid unnecessary string look-ups of clk_core's possible parents. */ + core->parents = kcalloc(core->num_parents, sizeof(*core->parents), + GFP_KERNEL); + if (!core->parents) { + ret = -ENOMEM; + goto fail_parents; + }; + INIT_HLIST_HEAD(&core->clks); hw->clk = __clk_create_clk(hw, NULL, NULL); if (IS_ERR(hw->clk)) { ret = PTR_ERR(hw->clk); - goto fail_parent_names_copy; + goto fail_parents; } - ret = __clk_init(dev, hw->clk); + ret = __clk_core_init(core); if (!ret) return hw->clk; __clk_free_clk(hw->clk); hw->clk = NULL; +fail_parents: + kfree(core->parents); fail_parent_names_copy: while (--i >= 0) kfree_const(core->parent_names[i]); @@ -2683,7 +2606,7 @@ void clk_unregister(struct clk *clk) if (clk->core->ops == &clk_nodrv_ops) { pr_err("%s: unregistered clock: %s\n", __func__, clk->core->name); - return; + goto unlock; } /* * Assign empty clock ops for consumers that might still hold @@ -2709,7 +2632,7 @@ void clk_unregister(struct clk *clk) pr_warn("%s: unregistering prepared clock: %s\n", __func__, clk->core->name); kref_put(&clk->core->ref, __clk_release); - +unlock: clk_prepare_unlock(); } EXPORT_SYMBOL_GPL(clk_unregister); @@ -3061,10 +2984,23 @@ struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) { return __of_clk_get_from_provider(clkspec, NULL, __func__); } +EXPORT_SYMBOL_GPL(of_clk_get_from_provider); -int of_clk_get_parent_count(struct device_node *np) +/** + * of_clk_get_parent_count() - Count the number of clocks a device node has + * @np: device node to count + * + * Returns: The number of clocks that are possible parents of this node + */ +unsigned int of_clk_get_parent_count(struct device_node *np) { - return of_count_phandle_with_args(np, "clocks", "#clock-cells"); + int count; + + count = of_count_phandle_with_args(np, "clocks", "#clock-cells"); + if (count < 0) + return 0; + + return count; } EXPORT_SYMBOL_GPL(of_clk_get_parent_count); @@ -3214,6 +3150,9 @@ void __init of_clk_init(const struct of_device_id *matches) for_each_matching_node_and_match(np, matches, &match) { struct clock_provider *parent; + if (!of_device_is_available(np)) + continue; + parent = kzalloc(sizeof(*parent), GFP_KERNEL); if (!parent) { list_for_each_entry_safe(clk_provider, next, |