diff options
Diffstat (limited to 'arch/sh/kernel/clkdev.c')
-rw-r--r-- | arch/sh/kernel/clkdev.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/arch/sh/kernel/clkdev.c b/arch/sh/kernel/clkdev.c new file mode 100644 index 000000000000..defdd6e30908 --- /dev/null +++ b/arch/sh/kernel/clkdev.c @@ -0,0 +1,169 @@ +/* + * 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 <linux/slab.h> +#include <linux/bootmem.h> +#include <linux/mm.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 * __init_refok +clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...) +{ + struct clk_lookup_alloc *cla; + + if (!slab_is_available()) + cla = alloc_bootmem_low_pages(sizeof(*cla)); + else + 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); |