Linux 内核clk 添加clk provider

内核把所有的clk  provider管理维护起来，这些存放在of_clk_providers链表当中，

这个provider定义如下：

struct of_clk_provider { struct list_head link;
 struct device_node *node; struct clk *(*get)(struct of_phandle_args *clkspec, void *data); struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data); void *data;};

static LIST_HEAD(of_clk_providers);static DEFINE_MUTEX(of_clk_lock);

添加函数：

/** * of_clk_add_provider() - Register a clock provider for a node * @np: Device node pointer associated with clock provider * @clk_src_get: callback for decoding clock * @data: context pointer for @clk_src_get callback. */int of_clk_add_provider(struct device_node *np,   struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,         void *data),   void *data){ struct of_clk_provider *cp;
 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); if (!cp)  return -ENOMEM;
 cp->node = of_node_get(np); cp->data = data; cp->get = clk_src_get;
 mutex_lock(&of_clk_lock); list_add(&cp->link, &of_clk_providers); mutex_unlock(&of_clk_lock); pr_debug("Added clock from %s\n", np->full_name);
 return 0;}
删除操作/** * of_clk_del_provider() - Remove a previously registered clock provider * @np: Device node pointer associated with clock provider */void of_clk_del_provider(struct device_node *np){ struct of_clk_provider *cp;
 mutex_lock(&of_clk_lock); list_for_each_entry(cp, &of_clk_providers, link) {  if (cp->node == np) {   list_del(&cp->link);   of_node_put(cp->node);   kfree(cp);   break;  } } mutex_unlock(&of_clk_lock);}
获取clk：
struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec){ struct of_clk_provider *provider; struct clk *clk = ERR_PTR(-ENOENT);
 /* Check if we have such a provider in our array */ mutex_lock(&of_clk_lock); list_for_each_entry(provider, &of_clk_providers, link) {  if (provider->node == clkspec->np)   clk = provider->get(clkspec, provider->data);  if (!IS_ERR(clk))   break; } mutex_unlock(&of_clk_lock);
 return clk;}