Commit 0318e693 authored by Russell King's avatar Russell King Committed by Russell King
Browse files

[ARM] clkdev: add generic clkdev infrastructure



Add some generic infrastructure to assist looking up struct clks
for the ARM architecture.
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent ed313489
......@@ -33,3 +33,6 @@ config SHARPSL_PM
config SHARP_SCOOP
bool
config COMMON_CLKDEV
bool
......@@ -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
/*
* 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);
/*
* 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
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