Initial import

1 files changed, 374 insertions, 0 deletions

diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
new file mode 100644
index 000000000..1fcb6ef2c
--- /dev/null
+++ b/drivers/clk/clkdev.c
@@ -0,0 +1,374 @@
+/*
+ * drivers/clk/clkdev.c
+ *
+ *  Copyright (C) 2008 Russell King.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Helper for the clk API to assist looking up a struct clk.
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include <linux/mutex.h>
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.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)
+static struct clk *__of_clk_get(struct device_node *np, int index,
+			       const char *dev_id, const char *con_id)
+{
+	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_from_provider(&clkspec, dev_id, con_id);
+	of_node_put(clkspec.np);
+
+	return clk;
+}
+
+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);
+
+static struct clk *__of_clk_get_by_name(struct device_node *np,
+					const char *dev_id,
+					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, dev_id, name);
+		if (!IS_ERR(clk)) {
+			break;
+		} else if (name && index >= 0) {
+			if (PTR_ERR(clk) != -EPROBE_DEFER)
+				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;
+}
+
+/**
+ * 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_by_name(np, np->full_name, name);
+}
+EXPORT_SYMBOL(of_clk_get_by_name);
+
+#else /* defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) */
+
+static struct clk *__of_clk_get_by_name(struct device_node *np,
+					const char *dev_id,
+					const char *name)
+{
+	return ERR_PTR(-ENOENT);
+}
+#endif
+
+/*
+ * Find the correct struct clk for the device and connection ID.
+ * We do slightly fuzzy matching here:
+ *  An entry with a NULL ID is assumed to be a wildcard.
+ *  If an entry has a device ID, it must match
+ *  If an entry has a connection ID, it must match
+ * Then we take the most specific entry - with the following
+ * order of precedence: dev+con > dev only > con only.
+ */
+static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
+{
+	struct clk_lookup *p, *cl = NULL;
+	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;
+		if (p->dev_id) {
+			if (!dev_id || strcmp(p->dev_id, dev_id))
+				continue;
+			match += 2;
+		}
+		if (p->con_id) {
+			if (!con_id || strcmp(p->con_id, con_id))
+				continue;
+			match += 1;
+		}
+
+		if (match > best_found) {
+			cl = p;
+			if (match != best_possible)
+				best_found = match;
+			else
+				break;
+		}
+	}
+	return cl;
+}
+
+struct clk *clk_get_sys(const char *dev_id, const char *con_id)
+{
+	struct clk_lookup *cl;
+	struct clk *clk = NULL;
+
+	mutex_lock(&clocks_mutex);
+
+	cl = clk_find(dev_id, con_id);
+	if (!cl)
+		goto out;
+
+	clk = __clk_create_clk(__clk_get_hw(cl->clk), dev_id, con_id);
+	if (IS_ERR(clk))
+		goto out;
+
+	if (!__clk_get(clk)) {
+		__clk_free_clk(clk);
+		cl = NULL;
+		goto out;
+	}
+
+out:
+	mutex_unlock(&clocks_mutex);
+
+	return cl ? clk : ERR_PTR(-ENOENT);
+}
+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, dev_id, con_id);
+		if (!IS_ERR(clk) || PTR_ERR(clk) == -EPROBE_DEFER)
+			return clk;
+	}
+
+	return clk_get_sys(dev_id, con_id);
+}
+EXPORT_SYMBOL(clk_get);
+
+void clk_put(struct clk *clk)
+{
+	__clk_put(clk);
+}
+EXPORT_SYMBOL(clk_put);
+
+void clkdev_add(struct clk_lookup *cl)
+{
+	mutex_lock(&clocks_mutex);
+	list_add_tail(&cl->node, &clocks);
+	mutex_unlock(&clocks_mutex);
+}
+EXPORT_SYMBOL(clkdev_add);
+
+void __init clkdev_add_table(struct clk_lookup *cl, size_t num)
+{
+	mutex_lock(&clocks_mutex);
+	while (num--) {
+		list_add_tail(&cl->node, &clocks);
+		cl++;
+	}
+	mutex_unlock(&clocks_mutex);
+}
+
+#define MAX_DEV_ID	20
+#define MAX_CON_ID	16
+
+struct clk_lookup_alloc {
+	struct clk_lookup cl;
+	char	dev_id[MAX_DEV_ID];
+	char	con_id[MAX_CON_ID];
+};
+
+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;
+
+	cla = __clkdev_alloc(sizeof(*cla));
+	if (!cla)
+		return NULL;
+
+	cla->cl.clk = clk;
+	if (con_id) {
+		strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
+		cla->cl.con_id = cla->con_id;
+	}
+
+	if (dev_fmt) {
+		vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
+		cla->cl.dev_id = cla->dev_id;
+	}
+
+	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,
+	struct device *dev)
+{
+	struct clk *r = clk_get(dev, id);
+	struct clk_lookup *l;
+
+	if (IS_ERR(r))
+		return PTR_ERR(r);
+
+	l = clkdev_alloc(r, alias, alias_dev_name);
+	clk_put(r);
+	if (!l)
+		return -ENODEV;
+	clkdev_add(l);
+	return 0;
+}
+EXPORT_SYMBOL(clk_add_alias);
+
+/*
+ * clkdev_drop - remove a clock dynamically allocated
+ */
+void clkdev_drop(struct clk_lookup *cl)
+{
+	mutex_lock(&clocks_mutex);
+	list_del(&cl->node);
+	mutex_unlock(&clocks_mutex);
+	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;
+}
+EXPORT_SYMBOL(clk_register_clkdev);
+
+/**
+ * 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);