diff options
Diffstat (limited to 'drivers/clk/clk.c')
-rw-r--r-- | drivers/clk/clk.c | 144 |
1 files changed, 118 insertions, 26 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 5517944495d8..dff0373f53c1 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -277,6 +277,10 @@ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) if (!d) goto err_out; + if (clk->ops->debug_init) + if (clk->ops->debug_init(clk->hw, clk->dentry)) + goto err_out; + ret = 0; goto out; @@ -1339,8 +1343,11 @@ static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) if (clk->notifier_count) ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); - if (ret & NOTIFY_STOP_MASK) + if (ret & NOTIFY_STOP_MASK) { + pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n", + __func__, clk->name, ret); goto out; + } hlist_for_each_entry(child, &clk->children, child_node) { ret = __clk_speculate_rates(child, new_rate); @@ -1588,7 +1595,7 @@ int clk_set_rate(struct clk *clk, unsigned long rate) /* notify that we are about to change rates */ fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); if (fail_clk) { - pr_warn("%s: failed to set %s rate\n", __func__, + pr_debug("%s: failed to set %s rate\n", __func__, fail_clk->name); clk_propagate_rate_change(top, ABORT_RATE_CHANGE); ret = -EBUSY; @@ -2226,24 +2233,25 @@ EXPORT_SYMBOL_GPL(devm_clk_unregister); */ int __clk_get(struct clk *clk) { - if (clk && !try_module_get(clk->owner)) - return 0; + if (clk) { + if (!try_module_get(clk->owner)) + return 0; - kref_get(&clk->ref); + kref_get(&clk->ref); + } return 1; } void __clk_put(struct clk *clk) { - if (WARN_ON_ONCE(IS_ERR(clk))) + if (!clk || WARN_ON_ONCE(IS_ERR(clk))) return; clk_prepare_lock(); kref_put(&clk->ref, __clk_release); clk_prepare_unlock(); - if (clk) - module_put(clk->owner); + module_put(clk->owner); } /*** clk rate change notifiers ***/ @@ -2259,20 +2267,11 @@ void __clk_put(struct clk *clk) * re-enter into the clk framework by calling any top-level clk APIs; * this will cause a nested prepare_lock mutex. * - * Pre-change notifier callbacks will be passed the current, pre-change - * rate of the clk via struct clk_notifier_data.old_rate. The new, - * post-change rate of the clk is passed via struct + * In all notification cases cases (pre, post and abort rate change) the + * original clock rate is passed to the callback via struct + * clk_notifier_data.old_rate and the new frequency is passed via struct * clk_notifier_data.new_rate. * - * Post-change notifiers will pass the now-current, post-change rate of - * the clk in both struct clk_notifier_data.old_rate and struct - * clk_notifier_data.new_rate. - * - * Abort-change notifiers are effectively the opposite of pre-change - * notifiers: the original pre-change clk rate is passed in via struct - * clk_notifier_data.new_rate and the failed post-change rate is passed - * in via struct clk_notifier_data.old_rate. - * * clk_notifier_register() must be called from non-atomic context. * Returns -EINVAL if called with null arguments, -ENOMEM upon * allocation failure; otherwise, passes along the return value of @@ -2472,7 +2471,7 @@ EXPORT_SYMBOL_GPL(of_clk_del_provider); struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec) { struct of_clk_provider *provider; - struct clk *clk = ERR_PTR(-ENOENT); + struct clk *clk = ERR_PTR(-EPROBE_DEFER); /* Check if we have such a provider in our array */ list_for_each_entry(provider, &of_clk_providers, link) { @@ -2505,8 +2504,12 @@ EXPORT_SYMBOL_GPL(of_clk_get_parent_count); const char *of_clk_get_parent_name(struct device_node *np, int index) { struct of_phandle_args clkspec; + struct property *prop; const char *clk_name; + const __be32 *vp; + u32 pv; int rc; + int count; if (index < 0) return NULL; @@ -2516,8 +2519,22 @@ const char *of_clk_get_parent_name(struct device_node *np, int index) if (rc) return NULL; + index = clkspec.args_count ? clkspec.args[0] : 0; + count = 0; + + /* if there is an indices property, use it to transfer the index + * specified into an array offset for the clock-output-names property. + */ + of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) { + if (index == pv) { + index = count; + break; + } + count++; + } + if (of_property_read_string_index(clkspec.np, "clock-output-names", - clkspec.args_count ? clkspec.args[0] : 0, + index, &clk_name) < 0) clk_name = clkspec.np->name; @@ -2526,24 +2543,99 @@ const char *of_clk_get_parent_name(struct device_node *np, int index) } EXPORT_SYMBOL_GPL(of_clk_get_parent_name); +struct clock_provider { + of_clk_init_cb_t clk_init_cb; + struct device_node *np; + struct list_head node; +}; + +static LIST_HEAD(clk_provider_list); + +/* + * This function looks for a parent clock. If there is one, then it + * checks that the provider for this parent clock was initialized, in + * this case the parent clock will be ready. + */ +static int parent_ready(struct device_node *np) +{ + int i = 0; + + while (true) { + struct clk *clk = of_clk_get(np, i); + + /* this parent is ready we can check the next one */ + if (!IS_ERR(clk)) { + clk_put(clk); + i++; + continue; + } + + /* at least one parent is not ready, we exit now */ + if (PTR_ERR(clk) == -EPROBE_DEFER) + return 0; + + /* + * Here we make assumption that the device tree is + * written correctly. So an error means that there is + * no more parent. As we didn't exit yet, then the + * previous parent are ready. If there is no clock + * parent, no need to wait for them, then we can + * consider their absence as being ready + */ + return 1; + } +} + /** * of_clk_init() - Scan and init clock providers from the DT * @matches: array of compatible values and init functions for providers. * - * This function scans the device tree for matching clock providers and - * calls their initialization functions + * This function scans the device tree for matching clock providers + * and calls their initialization functions. It also does it by trying + * to follow the dependencies. */ void __init of_clk_init(const struct of_device_id *matches) { const struct of_device_id *match; struct device_node *np; + struct clock_provider *clk_provider, *next; + bool is_init_done; + bool force = false; if (!matches) matches = &__clk_of_table; + /* First prepare the list of the clocks providers */ for_each_matching_node_and_match(np, matches, &match) { - of_clk_init_cb_t clk_init_cb = match->data; - clk_init_cb(np); + struct clock_provider *parent = + kzalloc(sizeof(struct clock_provider), GFP_KERNEL); + + parent->clk_init_cb = match->data; + parent->np = np; + list_add_tail(&parent->node, &clk_provider_list); + } + + while (!list_empty(&clk_provider_list)) { + is_init_done = false; + list_for_each_entry_safe(clk_provider, next, + &clk_provider_list, node) { + if (force || parent_ready(clk_provider->np)) { + clk_provider->clk_init_cb(clk_provider->np); + list_del(&clk_provider->node); + kfree(clk_provider); + is_init_done = true; + } + } + + /* + * We didn't manage to initialize any of the + * remaining providers during the last loop, so now we + * initialize all the remaining ones unconditionally + * in case the clock parent was not mandatory + */ + if (!is_init_done) + force = true; + } } #endif |