aboutsummaryrefslogtreecommitdiff
path: root/arch/sh/kernel/clkdev.c
diff options
context:
space:
mode:
authorPaul Mundt <lethal@linux-sh.org>2010-03-08 21:45:19 +0900
committerPaul Mundt <lethal@linux-sh.org>2010-03-09 11:57:17 +0900
commit51a5006afcd13176276f0935ee57c4cc6f210e83 (patch)
treea5842fabed2ac33ac5b807d5764687babf5787d3 /arch/sh/kernel/clkdev.c
parent40d1f0048289b1baed859baee06878417fae540e (diff)
sh: Merge clkdev API updates.
This rolls in the remainder of the clkdev API bits from the ARM tree. This can more or less be used verbatim, so we just copy it over and nuke our local version. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/kernel/clkdev.c')
-rw-r--r--arch/sh/kernel/clkdev.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/arch/sh/kernel/clkdev.c b/arch/sh/kernel/clkdev.c
new file mode 100644
index 00000000000..29cd802ac38
--- /dev/null
+++ b/arch/sh/kernel/clkdev.c
@@ -0,0 +1,162 @@
+/*
+ * arch/sh/kernel/clkdev.c
+ *
+ * Cloned from arch/arm/common/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 <asm/clock.h>
+#include <asm/clkdev.h>
+
+static LIST_HEAD(clocks);
+static DEFINE_MUTEX(clocks_mutex);
+
+/*
+ * 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 precidence: dev+con > dev only > con only.
+ */
+static struct clk *clk_find(const char *dev_id, const char *con_id)
+{
+ struct clk_lookup *p;
+ struct clk *clk = NULL;
+ int match, best = 0;
+
+ 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 == 0)
+ continue;
+
+ if (match > best) {
+ clk = p->clk;
+ best = match;
+ }
+ }
+ return clk;
+}
+
+struct clk *clk_get_sys(const char *dev_id, const char *con_id)
+{
+ struct clk *clk;
+
+ mutex_lock(&clocks_mutex);
+ clk = clk_find(dev_id, con_id);
+ mutex_unlock(&clocks_mutex);
+
+ return clk ? clk : ERR_PTR(-ENOENT);
+}
+EXPORT_SYMBOL(clk_get_sys);
+
+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];
+};
+
+struct clk_lookup *clkdev_alloc(struct clk *clk, const char *con_id,
+ const char *dev_fmt, ...)
+{
+ struct clk_lookup_alloc *cla;
+
+ cla = kzalloc(sizeof(*cla), GFP_KERNEL);
+ 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) {
+ 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;
+}
+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);