diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/Makefile | 2 | ||||
| -rw-r--r-- | drivers/clk/Kconfig | 4 | ||||
| -rw-r--r-- | drivers/clk/Makefile | 2 | ||||
| -rw-r--r-- | drivers/clk/clkdev.c | 176 |
5 files changed, 186 insertions, 0 deletions
diff --git a/drivers/Kconfig b/drivers/Kconfig index a2b902f4d437..3d93b3a3d630 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -111,4 +111,6 @@ source "drivers/xen/Kconfig" source "drivers/staging/Kconfig" source "drivers/platform/Kconfig" + +source "drivers/clk/Kconfig" endmenu diff --git a/drivers/Makefile b/drivers/Makefile index 14cf9077bb2b..4af7d5b124ce 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -114,3 +114,5 @@ obj-$(CONFIG_VLYNQ) += vlynq/ obj-$(CONFIG_STAGING) += staging/ obj-y += platform/ obj-y += ieee802154/ +#common clk code +obj-y += clk/ diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig new file mode 100644 index 000000000000..4168c8896e16 --- /dev/null +++ b/drivers/clk/Kconfig @@ -0,0 +1,4 @@ + +config CLKDEV_LOOKUP + bool + select HAVE_CLK diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile new file mode 100644 index 000000000000..07613fa172c9 --- /dev/null +++ b/drivers/clk/Makefile @@ -0,0 +1,2 @@ + +obj-$(CONFIG_CLKDEV_LOOKUP) += clkdev.o diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c new file mode 100644 index 000000000000..0fc0a79852de --- /dev/null +++ b/drivers/clk/clkdev.c @@ -0,0 +1,176 @@ +/* + * drivers/clk/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/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 precedence: 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 > best) { + clk = p->clk; + if (match != 3) + best = match; + else + break; + } + } + 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); + if (clk && !__clk_get(clk)) + clk = NULL; + mutex_unlock(&clocks_mutex); + + return clk ? clk : ERR_PTR(-ENOENT); +} +EXPORT_SYMBOL(clk_get_sys); + +struct clk *clk_get(struct device *dev, const char *con_id) +{ + const char *dev_id = dev ? dev_name(dev) : NULL; + + return clk_get_sys(dev_id, con_id); +} +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); + +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; + + cla = __clkdev_alloc(sizeof(*cla)); + 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); |