diff options
author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-11-27 12:39:14 +0000 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-11-27 12:39:14 +0000 |
commit | e902be56cbf2a48d96d11d6884767e638d41c712 (patch) | |
tree | e4d79479a1280ad4841005680e37119d6694c3bf /arch/arm/common/clkdev.c | |
parent | c750815e2d436f4379c7af8a8770ef2ae71c5607 (diff) | |
parent | 5e1dbdb458ada37f7e97265cb2ea87c55fd5d034 (diff) |
Merge branches 'core' and 'clks' into devel
Diffstat (limited to 'arch/arm/common/clkdev.c')
-rw-r--r-- | arch/arm/common/clkdev.c | 128 |
1 files changed, 128 insertions, 0 deletions
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); |