diff options
Diffstat (limited to 'drivers/clk/clk.c')
| -rw-r--r-- | drivers/clk/clk.c | 178 |
1 files changed, 164 insertions, 14 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index c8d83acda006..647d056df88c 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -21,6 +21,7 @@ #include <linux/of.h> #include <linux/device.h> #include <linux/init.h> +#include <linux/pm_runtime.h> #include <linux/sched.h> #include <linux/clkdev.h> @@ -46,6 +47,7 @@ struct clk_core { const struct clk_ops *ops; struct clk_hw *hw; struct module *owner; + struct device *dev; struct clk_core *parent; const char **parent_names; struct clk_core **parents; @@ -87,6 +89,26 @@ struct clk { struct hlist_node clks_node; }; +/*** runtime pm ***/ +static int clk_pm_runtime_get(struct clk_core *core) +{ + int ret = 0; + + if (!core->dev) + return 0; + + ret = pm_runtime_get_sync(core->dev); + return ret < 0 ? ret : 0; +} + +static void clk_pm_runtime_put(struct clk_core *core) +{ + if (!core->dev) + return; + + pm_runtime_put_sync(core->dev); +} + /*** locking ***/ static void clk_prepare_lock(void) { @@ -150,6 +172,8 @@ static void clk_enable_unlock(unsigned long flags) static bool clk_core_is_prepared(struct clk_core *core) { + bool ret = false; + /* * .is_prepared is optional for clocks that can prepare * fall back to software usage counter if it is missing @@ -157,11 +181,18 @@ static bool clk_core_is_prepared(struct clk_core *core) if (!core->ops->is_prepared) return core->prepare_count; - return core->ops->is_prepared(core->hw); + if (!clk_pm_runtime_get(core)) { + ret = core->ops->is_prepared(core->hw); + clk_pm_runtime_put(core); + } + + return ret; } static bool clk_core_is_enabled(struct clk_core *core) { + bool ret = false; + /* * .is_enabled is only mandatory for clocks that gate * fall back to software usage counter if .is_enabled is missing @@ -169,7 +200,29 @@ static bool clk_core_is_enabled(struct clk_core *core) if (!core->ops->is_enabled) return core->enable_count; - return core->ops->is_enabled(core->hw); + /* + * Check if clock controller's device is runtime active before + * calling .is_enabled callback. If not, assume that clock is + * disabled, because we might be called from atomic context, from + * which pm_runtime_get() is not allowed. + * This function is called mainly from clk_disable_unused_subtree, + * which ensures proper runtime pm activation of controller before + * taking enable spinlock, but the below check is needed if one tries + * to call it from other places. + */ + if (core->dev) { + pm_runtime_get_noresume(core->dev); + if (!pm_runtime_active(core->dev)) { + ret = false; + goto done; + } + } + + ret = core->ops->is_enabled(core->hw); +done: + clk_pm_runtime_put(core); + + return ret; } /*** helper functions ***/ @@ -489,6 +542,8 @@ static void clk_core_unprepare(struct clk_core *core) if (core->ops->unprepare) core->ops->unprepare(core->hw); + clk_pm_runtime_put(core); + trace_clk_unprepare_complete(core); clk_core_unprepare(core->parent); } @@ -530,10 +585,14 @@ static int clk_core_prepare(struct clk_core *core) return 0; if (core->prepare_count == 0) { - ret = clk_core_prepare(core->parent); + ret = clk_pm_runtime_get(core); if (ret) return ret; + ret = clk_core_prepare(core->parent); + if (ret) + goto runtime_put; + trace_clk_prepare(core); if (core->ops->prepare) @@ -541,15 +600,18 @@ static int clk_core_prepare(struct clk_core *core) trace_clk_prepare_complete(core); - if (ret) { - clk_core_unprepare(core->parent); - return ret; - } + if (ret) + goto unprepare; } core->prepare_count++; return 0; +unprepare: + clk_core_unprepare(core->parent); +runtime_put: + clk_pm_runtime_put(core); + return ret; } static int clk_core_prepare_lock(struct clk_core *core) @@ -745,6 +807,9 @@ static void clk_unprepare_unused_subtree(struct clk_core *core) if (core->flags & CLK_IGNORE_UNUSED) return; + if (clk_pm_runtime_get(core)) + return; + if (clk_core_is_prepared(core)) { trace_clk_unprepare(core); if (core->ops->unprepare_unused) @@ -753,6 +818,8 @@ static void clk_unprepare_unused_subtree(struct clk_core *core) core->ops->unprepare(core->hw); trace_clk_unprepare_complete(core); } + + clk_pm_runtime_put(core); } static void clk_disable_unused_subtree(struct clk_core *core) @@ -768,6 +835,9 @@ static void clk_disable_unused_subtree(struct clk_core *core) if (core->flags & CLK_OPS_PARENT_ENABLE) clk_core_prepare_enable(core->parent); + if (clk_pm_runtime_get(core)) + goto unprepare_out; + flags = clk_enable_lock(); if (core->enable_count) @@ -792,6 +862,8 @@ static void clk_disable_unused_subtree(struct clk_core *core) unlock_out: clk_enable_unlock(flags); + clk_pm_runtime_put(core); +unprepare_out: if (core->flags & CLK_OPS_PARENT_ENABLE) clk_core_disable_unprepare(core->parent); } @@ -1038,9 +1110,13 @@ EXPORT_SYMBOL_GPL(clk_get_accuracy); static unsigned long clk_recalc(struct clk_core *core, unsigned long parent_rate) { - if (core->ops->recalc_rate) - return core->ops->recalc_rate(core->hw, parent_rate); - return parent_rate; + unsigned long rate = parent_rate; + + if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) { + rate = core->ops->recalc_rate(core->hw, parent_rate); + clk_pm_runtime_put(core); + } + return rate; } /** @@ -1565,6 +1641,7 @@ 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; if (!core) return 0; @@ -1581,21 +1658,28 @@ static int clk_core_set_rate_nolock(struct clk_core *core, if (!top) return -EINVAL; + ret = clk_pm_runtime_get(core); + if (ret) + return ret; + /* notify that we are about to change rates */ fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); if (fail_clk) { pr_debug("%s: failed to set %s rate\n", __func__, fail_clk->name); clk_propagate_rate_change(top, ABORT_RATE_CHANGE); - return -EBUSY; + ret = -EBUSY; + goto err; } /* change the rates */ clk_change_rate(top); core->req_rate = req_rate; +err: + clk_pm_runtime_put(core); - return 0; + return ret; } /** @@ -1826,12 +1910,16 @@ static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent) p_rate = parent->rate; } + ret = clk_pm_runtime_get(core); + if (ret) + goto out; + /* propagate PRE_RATE_CHANGE notifications */ ret = __clk_speculate_rates(core, p_rate); /* abort if a driver objects */ if (ret & NOTIFY_STOP_MASK) - goto out; + goto runtime_put; /* do the re-parent */ ret = __clk_set_parent(core, parent, p_index); @@ -1844,6 +1932,8 @@ static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent) __clk_recalc_accuracies(core); } +runtime_put: + clk_pm_runtime_put(core); out: clk_prepare_unlock(); @@ -2350,7 +2440,7 @@ static inline void clk_debug_unregister(struct clk_core *core) */ static int __clk_core_init(struct clk_core *core) { - int i, ret = 0; + int i, ret; struct clk_core *orphan; struct hlist_node *tmp2; unsigned long rate; @@ -2360,6 +2450,10 @@ static int __clk_core_init(struct clk_core *core) clk_prepare_lock(); + ret = clk_pm_runtime_get(core); + if (ret) + goto unlock; + /* check to see if a clock with this name is already registered */ if (clk_core_lookup(core->name)) { pr_debug("%s: clk %s already initialized\n", @@ -2512,6 +2606,8 @@ static int __clk_core_init(struct clk_core *core) kref_init(&core->ref); out: + clk_pm_runtime_put(core); +unlock: clk_prepare_unlock(); if (!ret) @@ -2583,6 +2679,8 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) goto fail_name; } core->ops = hw->init->ops; + if (dev && pm_runtime_enabled(dev)) + core->dev = dev; if (dev && dev->driver) core->owner = dev->driver->owner; core->hw = hw; @@ -3177,6 +3275,37 @@ int of_clk_add_hw_provider(struct device_node *np, } EXPORT_SYMBOL_GPL(of_clk_add_hw_provider); +static void devm_of_clk_release_provider(struct device *dev, void *res) +{ + of_clk_del_provider(*(struct device_node **)res); +} + +int devm_of_clk_add_hw_provider(struct device *dev, + struct clk_hw *(*get)(struct of_phandle_args *clkspec, + void *data), + void *data) +{ + struct device_node **ptr, *np; + int ret; + + ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr), + GFP_KERNEL); + if (!ptr) + return -ENOMEM; + + np = dev->of_node; + ret = of_clk_add_hw_provider(np, get, data); + if (!ret) { + *ptr = np; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return ret; +} +EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider); + /** * of_clk_del_provider() - Remove a previously registered clock provider * @np: Device node pointer associated with clock provider @@ -3198,6 +3327,27 @@ void of_clk_del_provider(struct device_node *np) } EXPORT_SYMBOL_GPL(of_clk_del_provider); +static int devm_clk_provider_match(struct device *dev, void *res, void *data) +{ + struct device_node **np = res; + + if (WARN_ON(!np || !*np)) + return 0; + + return *np == data; +} + +void devm_of_clk_del_provider(struct device *dev) +{ + int ret; + + ret = devres_release(dev, devm_of_clk_release_provider, + devm_clk_provider_match, dev->of_node); + + WARN_ON(ret); +} +EXPORT_SYMBOL(devm_of_clk_del_provider); + static struct clk_hw * __of_clk_get_hw_from_provider(struct of_clk_provider *provider, struct of_phandle_args *clkspec) |