diff options
Diffstat (limited to 'arch/arm/mach-ns9xxx/clock.c')
| -rw-r--r-- | arch/arm/mach-ns9xxx/clock.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/arch/arm/mach-ns9xxx/clock.c b/arch/arm/mach-ns9xxx/clock.c new file mode 100644 index 00000000000..f8639161068 --- /dev/null +++ b/arch/arm/mach-ns9xxx/clock.c @@ -0,0 +1,215 @@ +/* + * arch/arm/mach-ns9xxx/clock.c + * + * Copyright (C) 2007 by Digi International Inc. + * All rights reserved. + * + * 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. + */ +#include <linux/err.h> +#include <linux/module.h> +#include <linux/list.h> +#include <linux/clk.h> +#include <linux/string.h> +#include <linux/platform_device.h> + +#include <asm/semaphore.h> +#include "clock.h" + +static LIST_HEAD(clocks); +static DEFINE_SPINLOCK(clk_lock); + +struct clk *clk_get(struct device *dev, const char *id) +{ + struct clk *p, *ret = NULL, *retgen = NULL; + unsigned long flags; + int idno; + + if (dev == NULL || dev->bus != &platform_bus_type) + idno = -1; + else + idno = to_platform_device(dev)->id; + + spin_lock_irqsave(&clk_lock, flags); + list_for_each_entry(p, &clocks, node) { + if (strcmp(id, p->name) == 0) { + if (p->id == idno) { + if (!try_module_get(p->owner)) + continue; + ret = p; + break; + } else if (p->id == -1) + /* remember match with id == -1 in case there is + * no clock for idno */ + retgen = p; + } + } + + if (!ret && retgen && try_module_get(retgen->owner)) + ret = retgen; + + if (ret) + ++ret->refcount; + + spin_unlock_irqrestore(&clk_lock, flags); + + return ret ? ret : ERR_PTR(-ENOENT); +} +EXPORT_SYMBOL(clk_get); + +void clk_put(struct clk *clk) +{ + module_put(clk->owner); + --clk->refcount; +} +EXPORT_SYMBOL(clk_put); + +static int clk_enable_unlocked(struct clk *clk) +{ + int ret = 0; + if (clk->parent) { + ret = clk_enable_unlocked(clk->parent); + if (ret) + return ret; + } + + if (clk->usage++ == 0 && clk->endisable) + ret = clk->endisable(clk, 1); + + return ret; +} + +int clk_enable(struct clk *clk) +{ + int ret; + unsigned long flags; + + spin_lock_irqsave(&clk_lock, flags); + + ret = clk_enable_unlocked(clk); + + spin_unlock_irqrestore(&clk_lock, flags); + + return ret; +} +EXPORT_SYMBOL(clk_enable); + +static void clk_disable_unlocked(struct clk *clk) +{ + if (--clk->usage == 0 && clk->endisable) + clk->endisable(clk, 0); + + if (clk->parent) + clk_disable_unlocked(clk->parent); +} + +void clk_disable(struct clk *clk) +{ + unsigned long flags; + + spin_lock_irqsave(&clk_lock, flags); + + clk_disable_unlocked(clk); + + spin_unlock_irqrestore(&clk_lock, flags); +} +EXPORT_SYMBOL(clk_disable); + +unsigned long clk_get_rate(struct clk *clk) +{ + if (clk->get_rate) + return clk->get_rate(clk); + + if (clk->rate) + return clk->rate; + + if (clk->parent) + return clk_get_rate(clk->parent); + + return 0; +} +EXPORT_SYMBOL(clk_get_rate); + +int clk_register(struct clk *clk) +{ + unsigned long flags; + + spin_lock_irqsave(&clk_lock, flags); + + list_add(&clk->node, &clocks); + + if (clk->parent) + ++clk->parent->refcount; + + spin_unlock_irqrestore(&clk_lock, flags); + + return 0; +} + +int clk_unregister(struct clk *clk) +{ + int ret = 0; + unsigned long flags; + + spin_lock_irqsave(&clk_lock, flags); + + if (clk->usage || clk->refcount) + ret = -EBUSY; + else + list_del(&clk->node); + + if (clk->parent) + --clk->parent->refcount; + + spin_unlock_irqrestore(&clk_lock, flags); + + return ret; +} + +#if defined CONFIG_DEBUG_FS + +#include <linux/debugfs.h> +#include <linux/seq_file.h> + +static int clk_debugfs_show(struct seq_file *s, void *null) +{ + unsigned long flags; + struct clk *p; + + spin_lock_irqsave(&clk_lock, flags); + + list_for_each_entry(p, &clocks, node) + seq_printf(s, "%s.%d: usage=%lu refcount=%lu rate=%lu\n", + p->name, p->id, p->usage, p->refcount, + p->usage ? clk_get_rate(p) : 0); + + spin_unlock_irqrestore(&clk_lock, flags); + + return 0; +} + +static int clk_debugfs_open(struct inode *inode, struct file *file) +{ + return single_open(file, clk_debugfs_show, NULL); +} + +static struct file_operations clk_debugfs_operations = { + .open = clk_debugfs_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init clk_debugfs_init(void) +{ + struct dentry *dentry; + + dentry = debugfs_create_file("clk", S_IFREG | S_IRUGO, NULL, NULL, + &clk_debugfs_operations); + return IS_ERR(dentry) ? PTR_ERR(dentry) : 0; +} +subsys_initcall(clk_debugfs_init); + +#endif /* if defined CONFIG_DEBUG_FS */ |