1 files changed, 194 insertions, 10 deletions

diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index 6db161f64ae..f890b901c6b 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -19,10 +19,108 @@
 #include <linux/mutex.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>
+#include <linux/of.h>
+
+#include "clk.h"
 
 static LIST_HEAD(clocks);
 static DEFINE_MUTEX(clocks_mutex);
 
+#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
+
+/**
+ * of_clk_get_by_clkspec() - Lookup a clock form a clock provider
+ * @clkspec: pointer to a clock specifier data structure
+ *
+ * This function looks up a struct clk from the registered list of clock
+ * providers, an input is a clock specifier data structure as returned
+ * from the of_parse_phandle_with_args() function call.
+ */
+struct clk *of_clk_get_by_clkspec(struct of_phandle_args *clkspec)
+{
+	struct clk *clk;
+
+	if (!clkspec)
+		return ERR_PTR(-EINVAL);
+
+	of_clk_lock();
+	clk = __of_clk_get_from_provider(clkspec);
+
+	if (!IS_ERR(clk) && !__clk_get(clk))
+		clk = ERR_PTR(-ENOENT);
+
+	of_clk_unlock();
+	return clk;
+}
+
+struct clk *of_clk_get(struct device_node *np, int index)
+{
+	struct of_phandle_args clkspec;
+	struct clk *clk;
+	int rc;
+
+	if (index < 0)
+		return ERR_PTR(-EINVAL);
+
+	rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
+					&clkspec);
+	if (rc)
+		return ERR_PTR(rc);
+
+	clk = of_clk_get_by_clkspec(&clkspec);
+	of_node_put(clkspec.np);
+	return clk;
+}
+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)
+{
+	struct clk *clk = ERR_PTR(-ENOENT);
+
+	/* Walk up the tree of devices looking for a clock that matches */
+	while (np) {
+		int index = 0;
+
+		/*
+		 * 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_clk_get() will fail.
+		 */
+		if (name)
+			index = of_property_match_string(np, "clock-names", name);
+		clk = of_clk_get(np, index);
+		if (!IS_ERR(clk))
+			break;
+		else if (name && index >= 0) {
+			pr_err("ERROR: could not get clock %s:%s(%i)\n",
+				np->full_name, name ? name : "", index);
+			return clk;
+		}
+
+		/*
+		 * 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;
+	}
+
+	return clk;
+}
+EXPORT_SYMBOL(of_clk_get_by_name);
+#endif
+
 /*
  * Find the correct struct clk for the device and connection ID.
  * We do slightly fuzzy matching here:
@@ -35,7 +133,12 @@ static DEFINE_MUTEX(clocks_mutex);
 static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
 {
 	struct clk_lookup *p, *cl = NULL;
-	int match, best = 0;
+	int match, best_found = 0, best_possible = 0;
+
+	if (dev_id)
+		best_possible += 2;
+	if (con_id)
+		best_possible += 1;
 
 	list_for_each_entry(p, &clocks, node) {
 		match = 0;
@@ -50,10 +153,10 @@ static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
 			match += 1;
 		}
 
-		if (match > best) {
+		if (match > best_found) {
 			cl = p;
-			if (match != 3)
-				best = match;
+			if (match != best_possible)
+				best_found = match;
 			else
 				break;
 		}
@@ -78,6 +181,15 @@ EXPORT_SYMBOL(clk_get_sys);
 struct clk *clk_get(struct device *dev, const char *con_id)
 {
 	const char *dev_id = dev ? dev_name(dev) : NULL;
+	struct clk *clk;
+
+	if (dev) {
+		clk = of_clk_get_by_name(dev->of_node, con_id);
+		if (!IS_ERR(clk))
+			return clk;
+		if (PTR_ERR(clk) == -EPROBE_DEFER)
+			return clk;
+	}
 
 	return clk_get_sys(dev_id, con_id);
 }
@@ -116,8 +228,9 @@ struct clk_lookup_alloc {
 	char	con_id[MAX_CON_ID];
 };
 
-struct clk_lookup * __init_refok
-clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
+static struct clk_lookup * __init_refok
+vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt,
+	va_list ap)
 {
 	struct clk_lookup_alloc *cla;
 
@@ -132,16 +245,25 @@ clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
 	}
 
 	if (dev_fmt) {
-		va_list ap;
-
-		va_start(ap, dev_fmt);
 		vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
 		cla->cl.dev_id = cla->dev_id;
-		va_end(ap);
 	}
 
 	return &cla->cl;
 }
+
+struct clk_lookup * __init_refok
+clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
+{
+	struct clk_lookup *cl;
+	va_list ap;
+
+	va_start(ap, dev_fmt);
+	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
+	va_end(ap);
+
+	return cl;
+}
 EXPORT_SYMBOL(clkdev_alloc);
 
 int clk_add_alias(const char *alias, const char *alias_dev_name, char *id,
@@ -173,3 +295,65 @@ void clkdev_drop(struct clk_lookup *cl)
 	kfree(cl);
 }
 EXPORT_SYMBOL(clkdev_drop);
+
+/**
+ * clk_register_clkdev - register one clock lookup for a struct clk
+ * @clk: struct clk to associate with all clk_lookups
+ * @con_id: connection ID string on device
+ * @dev_id: format string describing device name
+ *
+ * con_id or dev_id may be NULL as a wildcard, just as in the rest of
+ * clkdev.
+ *
+ * To make things easier for mass registration, we detect error clks
+ * from a previous clk_register() call, and return the error code for
+ * those.  This is to permit this function to be called immediately
+ * after clk_register().
+ */
+int clk_register_clkdev(struct clk *clk, const char *con_id,
+	const char *dev_fmt, ...)
+{
+	struct clk_lookup *cl;
+	va_list ap;
+
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	va_start(ap, dev_fmt);
+	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
+	va_end(ap);
+
+	if (!cl)
+		return -ENOMEM;
+
+	clkdev_add(cl);
+
+	return 0;
+}
+
+/**
+ * clk_register_clkdevs - register a set of clk_lookup for a struct clk
+ * @clk: struct clk to associate with all clk_lookups
+ * @cl: array of clk_lookup structures with con_id and dev_id pre-initialized
+ * @num: number of clk_lookup structures to register
+ *
+ * To make things easier for mass registration, we detect error clks
+ * from a previous clk_register() call, and return the error code for
+ * those.  This is to permit this function to be called immediately
+ * after clk_register().
+ */
+int clk_register_clkdevs(struct clk *clk, struct clk_lookup *cl, size_t num)
+{
+	unsigned i;
+
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	for (i = 0; i < num; i++, cl++) {
+		cl->clk = clk;
+		clkdev_add(cl);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(clk_register_clkdevs);