diff options
Diffstat (limited to 'drivers/clk/clk.c')
-rw-r--r-- | drivers/clk/clk.c | 259 |
1 files changed, 203 insertions, 56 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index af3882f04080..14cbf239d9b2 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -57,6 +57,7 @@ struct clk_core { struct clk_core *new_child; unsigned long flags; bool orphan; + bool rpm_enabled; unsigned int enable_count; unsigned int prepare_count; unsigned int protect_count; @@ -81,6 +82,7 @@ struct clk_core { struct clk { struct clk_core *core; + struct device *dev; const char *dev_id; const char *con_id; unsigned long min_rate; @@ -92,9 +94,9 @@ struct clk { /*** runtime pm ***/ static int clk_pm_runtime_get(struct clk_core *core) { - int ret = 0; + int ret; - if (!core->dev) + if (!core->rpm_enabled) return 0; ret = pm_runtime_get_sync(core->dev); @@ -103,7 +105,7 @@ static int clk_pm_runtime_get(struct clk_core *core) static void clk_pm_runtime_put(struct clk_core *core) { - if (!core->dev) + if (!core->rpm_enabled) return; pm_runtime_put_sync(core->dev); @@ -223,7 +225,7 @@ static bool clk_core_is_enabled(struct clk_core *core) * taking enable spinlock, but the below check is needed if one tries * to call it from other places. */ - if (core->dev) { + if (core->rpm_enabled) { pm_runtime_get_noresume(core->dev); if (!pm_runtime_active(core->dev)) { ret = false; @@ -233,7 +235,7 @@ static bool clk_core_is_enabled(struct clk_core *core) ret = core->ops->is_enabled(core->hw); done: - if (core->dev) + if (core->rpm_enabled) pm_runtime_put(core->dev); return ret; @@ -3212,43 +3214,106 @@ unlock: return ret; } -struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id, +/** + * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core + * @core: clk to add consumer to + * @clk: consumer to link to a clk + */ +static void clk_core_link_consumer(struct clk_core *core, struct clk *clk) +{ + clk_prepare_lock(); + hlist_add_head(&clk->clks_node, &core->clks); + clk_prepare_unlock(); +} + +/** + * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core + * @clk: consumer to unlink + */ +static void clk_core_unlink_consumer(struct clk *clk) +{ + lockdep_assert_held(&prepare_lock); + hlist_del(&clk->clks_node); +} + +/** + * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core + * @core: clk to allocate a consumer for + * @dev_id: string describing device name + * @con_id: connection ID string on device + * + * Returns: clk consumer left unlinked from the consumer list + */ +static struct clk *alloc_clk(struct clk_core *core, const char *dev_id, const char *con_id) { struct clk *clk; - /* This is to allow this function to be chained to others */ - if (IS_ERR_OR_NULL(hw)) - return ERR_CAST(hw); - clk = kzalloc(sizeof(*clk), GFP_KERNEL); if (!clk) return ERR_PTR(-ENOMEM); - clk->core = hw->core; + clk->core = core; clk->dev_id = dev_id; clk->con_id = kstrdup_const(con_id, GFP_KERNEL); clk->max_rate = ULONG_MAX; - clk_prepare_lock(); - hlist_add_head(&clk->clks_node, &hw->core->clks); - clk_prepare_unlock(); - return clk; } -/* keep in sync with __clk_put */ -void __clk_free_clk(struct clk *clk) +/** + * free_clk - Free a clk consumer + * @clk: clk consumer to free + * + * Note, this assumes the clk has been unlinked from the clk_core consumer + * list. + */ +static void free_clk(struct clk *clk) { - clk_prepare_lock(); - hlist_del(&clk->clks_node); - clk_prepare_unlock(); - kfree_const(clk->con_id); kfree(clk); } /** + * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given + * a clk_hw + * @dev: clk consumer device + * @hw: clk_hw associated with the clk being consumed + * @dev_id: string describing device name + * @con_id: connection ID string on device + * + * This is the main function used to create a clk pointer for use by clk + * consumers. It connects a consumer to the clk_core and clk_hw structures + * used by the framework and clk provider respectively. + */ +struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw, + const char *dev_id, const char *con_id) +{ + struct clk *clk; + struct clk_core *core; + + /* This is to allow this function to be chained to others */ + if (IS_ERR_OR_NULL(hw)) + return ERR_CAST(hw); + + core = hw->core; + clk = alloc_clk(core, dev_id, con_id); + if (IS_ERR(clk)) + return clk; + clk->dev = dev; + + if (!try_module_get(core->owner)) { + free_clk(clk); + return ERR_PTR(-ENOENT); + } + + kref_get(&core->ref); + clk_core_link_consumer(core, clk); + + return clk; +} + +/** * clk_register - allocate a new clock, register it and return an opaque cookie * @dev: device that is registering this clock * @hw: link to hardware-specific clock data @@ -3283,7 +3348,8 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) core->ops = hw->init->ops; if (dev && pm_runtime_enabled(dev)) - core->dev = dev; + core->rpm_enabled = true; + core->dev = dev; if (dev && dev->driver) core->owner = dev->driver->owner; core->hw = hw; @@ -3323,17 +3389,27 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) INIT_HLIST_HEAD(&core->clks); - hw->clk = __clk_create_clk(hw, NULL, NULL); + /* + * Don't call clk_hw_create_clk() here because that would pin the + * provider module to itself and prevent it from ever being removed. + */ + hw->clk = alloc_clk(core, NULL, NULL); if (IS_ERR(hw->clk)) { ret = PTR_ERR(hw->clk); goto fail_parents; } + clk_core_link_consumer(hw->core, hw->clk); + ret = __clk_core_init(core); if (!ret) return hw->clk; - __clk_free_clk(hw->clk); + clk_prepare_lock(); + clk_core_unlink_consumer(hw->clk); + clk_prepare_unlock(); + + free_clk(hw->clk); hw->clk = NULL; fail_parents: @@ -3604,20 +3680,7 @@ EXPORT_SYMBOL_GPL(devm_clk_hw_unregister); /* * clkdev helpers */ -int __clk_get(struct clk *clk) -{ - struct clk_core *core = !clk ? NULL : clk->core; - - if (core) { - if (!try_module_get(core->owner)) - return 0; - kref_get(&core->ref); - } - return 1; -} - -/* keep in sync with __clk_free_clk */ void __clk_put(struct clk *clk) { struct module *owner; @@ -3651,8 +3714,7 @@ void __clk_put(struct clk *clk) module_put(owner); - kfree_const(clk->con_id); - kfree(clk); + free_clk(clk); } /*** clk rate change notifiers ***/ @@ -4009,6 +4071,49 @@ void devm_of_clk_del_provider(struct device *dev) } EXPORT_SYMBOL(devm_of_clk_del_provider); +/* + * Beware the return values when np is valid, but no clock provider is found. + * If name == NULL, the function returns -ENOENT. + * If name != NULL, the function returns -EINVAL. This is because + * of_parse_phandle_with_args() is called even if of_property_match_string() + * returns an error. + */ +static int of_parse_clkspec(const struct device_node *np, int index, + const char *name, struct of_phandle_args *out_args) +{ + int ret = -ENOENT; + + /* Walk up the tree of devices looking for a clock property that matches */ + while (np) { + /* + * For named clocks, first look up the name in the + * "clock-names" property. If it cannot be found, then index + * will be an error code and of_parse_phandle_with_args() will + * return -EINVAL. + */ + if (name) + index = of_property_match_string(np, "clock-names", name); + ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells", + index, out_args); + if (!ret) + break; + if (name && index >= 0) + break; + + /* + * No matching clock found on this node. If the parent node + * has a "clock-ranges" property, then we can try one of its + * clocks. + */ + np = np->parent; + if (np && !of_get_property(np, "clock-ranges", NULL)) + break; + index = 0; + } + + return ret; +} + static struct clk_hw * __of_clk_get_hw_from_provider(struct of_clk_provider *provider, struct of_phandle_args *clkspec) @@ -4024,36 +4129,26 @@ __of_clk_get_hw_from_provider(struct of_clk_provider *provider, return __clk_get_hw(clk); } -struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec, - const char *dev_id, const char *con_id) +static struct clk_hw * +of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec) { struct of_clk_provider *provider; - struct clk *clk = ERR_PTR(-EPROBE_DEFER); - struct clk_hw *hw; + struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER); if (!clkspec) return ERR_PTR(-EINVAL); - /* Check if we have such a provider in our array */ mutex_lock(&of_clk_mutex); list_for_each_entry(provider, &of_clk_providers, link) { if (provider->node == clkspec->np) { hw = __of_clk_get_hw_from_provider(provider, clkspec); - clk = __clk_create_clk(hw, dev_id, con_id); - } - - if (!IS_ERR(clk)) { - if (!__clk_get(clk)) { - __clk_free_clk(clk); - clk = ERR_PTR(-ENOENT); - } - - break; + if (!IS_ERR(hw)) + break; } } mutex_unlock(&of_clk_mutex); - return clk; + return hw; } /** @@ -4066,10 +4161,62 @@ struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec, */ struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) { - return __of_clk_get_from_provider(clkspec, NULL, __func__); + struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec); + + return clk_hw_create_clk(NULL, hw, NULL, __func__); } EXPORT_SYMBOL_GPL(of_clk_get_from_provider); +struct clk_hw *of_clk_get_hw(struct device_node *np, int index, + const char *con_id) +{ + int ret; + struct clk_hw *hw; + struct of_phandle_args clkspec; + + ret = of_parse_clkspec(np, index, con_id, &clkspec); + if (ret) + return ERR_PTR(ret); + + hw = of_clk_get_hw_from_clkspec(&clkspec); + of_node_put(clkspec.np); + + return hw; +} + +static struct clk *__of_clk_get(struct device_node *np, + int index, const char *dev_id, + const char *con_id) +{ + struct clk_hw *hw = of_clk_get_hw(np, index, con_id); + + return clk_hw_create_clk(NULL, hw, dev_id, con_id); +} + +struct clk *of_clk_get(struct device_node *np, int index) +{ + return __of_clk_get(np, index, np->full_name, NULL); +} +EXPORT_SYMBOL(of_clk_get); + +/** + * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node + * @np: pointer to clock consumer node + * @name: name of consumer's clock input, or NULL for the first clock reference + * + * This function parses the clocks and clock-names properties, + * and uses them to look up the struct clk from the registered list of clock + * providers. + */ +struct clk *of_clk_get_by_name(struct device_node *np, const char *name) +{ + if (!np) + return ERR_PTR(-ENOENT); + + return __of_clk_get(np, -1, np->full_name, name); +} +EXPORT_SYMBOL(of_clk_get_by_name); + /** * of_clk_get_parent_count() - Count the number of clocks a device node has * @np: device node to count |