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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2008-11-09 16:32:46 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2008-11-27 12:38:21 +0000
commit0318e693d3a56836632bf1a2cfdafb7f34bcc703 (patch)
treef31f9e227681b4a9251381442384aca20e59f840
parented313489badef16d700f5a3be50e8fd8f8294bc8 (diff)
downloadvexpress-lsk-0318e693d3a56836632bf1a2cfdafb7f34bcc703.tar.gz
[ARM] clkdev: add generic clkdev infrastructure
Add some generic infrastructure to assist looking up struct clks for the ARM architecture. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/common/Kconfig3
-rw-r--r--arch/arm/common/Makefile1
-rw-r--r--arch/arm/common/clkdev.c128
-rw-r--r--arch/arm/include/asm/clkdev.h30
4 files changed, 162 insertions, 0 deletions
diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
index 86b5e698266..a2cd9beaf37 100644
--- a/arch/arm/common/Kconfig
+++ b/arch/arm/common/Kconfig
@@ -33,3 +33,6 @@ config SHARPSL_PM
config SHARP_SCOOP
bool
+
+config COMMON_CLKDEV
+ bool
diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index 325e4b6a6af..7cb7961d81c 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -17,3 +17,4 @@ obj-$(CONFIG_SHARP_SCOOP) += scoop.o
obj-$(CONFIG_ARCH_IXP2000) += uengine.o
obj-$(CONFIG_ARCH_IXP23XX) += uengine.o
obj-$(CONFIG_PCI_HOST_ITE8152) += it8152.o
+obj-$(CONFIG_COMMON_CLKDEV) += clkdev.o
diff --git a/arch/arm/common/clkdev.c b/arch/arm/common/clkdev.c
new file mode 100644
index 00000000000..17a17b49a45
--- /dev/null
+++ b/arch/arm/common/clkdev.c
@@ -0,0 +1,128 @@
+/*
+ * 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 <asm/clkdev.h>
+#include <mach/clkdev.h>
+
+static LIST_HEAD(clocks);
+static DEFINE_MUTEX(clocks_mutex);
+
+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) {
+ if ((p->dev_id && !dev_id) || (p->con_id && !con_id))
+ continue;
+ match = 0;
+ if (p->dev_id)
+ match += 2 * (strcmp(p->dev_id, dev_id) == 0);
+ if (p->con_id)
+ match += 1 * (strcmp(p->con_id, con_id) == 0);
+ if (match == 0)
+ continue;
+
+ if (match > best) {
+ clk = p->clk;
+ best = match;
+ }
+ }
+ return clk;
+}
+
+struct clk *clk_get(struct device *dev, const char *con_id)
+{
+ const char *dev_id = dev ? dev_name(dev) : NULL;
+ struct clk *clk;
+
+ mutex_lock(&clocks_mutex);
+ clk = clk_find(dev_id, con_id);
+ if (clk && !__clk_get(clk))
+ clk = NULL;
+ mutex_unlock(&clocks_mutex);
+
+ return clk ? clk : ERR_PTR(-ENOENT);
+}
+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);
+
+#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);
+
+/*
+ * 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);
diff --git a/arch/arm/include/asm/clkdev.h b/arch/arm/include/asm/clkdev.h
new file mode 100644
index 00000000000..b6ec7c627b3
--- /dev/null
+++ b/arch/arm/include/asm/clkdev.h
@@ -0,0 +1,30 @@
+/*
+ * arch/arm/include/asm/clkdev.h
+ *
+ * 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.
+ */
+#ifndef __ASM_CLKDEV_H
+#define __ASM_CLKDEV_H
+
+struct clk;
+
+struct clk_lookup {
+ struct list_head node;
+ const char *dev_id;
+ const char *con_id;
+ struct clk *clk;
+};
+
+struct clk_lookup *clkdev_alloc(struct clk *clk, const char *con_id,
+ const char *dev_fmt, ...);
+
+void clkdev_add(struct clk_lookup *cl);
+void clkdev_drop(struct clk_lookup *cl);
+
+#endif