| Russell King | 0318e69 | 2008-11-09 16:32:46 +0000 | [diff] [blame] | 1 | /* |
| 2 | * arch/arm/common/clkdev.c |
| 3 | * |
| 4 | * Copyright (C) 2008 Russell King. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | * Helper for the clk API to assist looking up a struct clk. |
| 11 | */ |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/device.h> |
| 15 | #include <linux/list.h> |
| 16 | #include <linux/errno.h> |
| 17 | #include <linux/err.h> |
| 18 | #include <linux/string.h> |
| 19 | #include <linux/mutex.h> |
| 20 | |
| 21 | #include <asm/clkdev.h> |
| 22 | #include <mach/clkdev.h> |
| 23 | |
| 24 | static LIST_HEAD(clocks); |
| 25 | static DEFINE_MUTEX(clocks_mutex); |
| 26 | |
| 27 | static struct clk *clk_find(const char *dev_id, const char *con_id) |
| 28 | { |
| 29 | struct clk_lookup *p; |
| 30 | struct clk *clk = NULL; |
| 31 | int match, best = 0; |
| 32 | |
| 33 | list_for_each_entry(p, &clocks, node) { |
| 34 | if ((p->dev_id && !dev_id) || (p->con_id && !con_id)) |
| 35 | continue; |
| 36 | match = 0; |
| 37 | if (p->dev_id) |
| 38 | match += 2 * (strcmp(p->dev_id, dev_id) == 0); |
| 39 | if (p->con_id) |
| 40 | match += 1 * (strcmp(p->con_id, con_id) == 0); |
| 41 | if (match == 0) |
| 42 | continue; |
| 43 | |
| 44 | if (match > best) { |
| 45 | clk = p->clk; |
| 46 | best = match; |
| 47 | } |
| 48 | } |
| 49 | return clk; |
| 50 | } |
| 51 | |
| 52 | struct clk *clk_get(struct device *dev, const char *con_id) |
| 53 | { |
| 54 | const char *dev_id = dev ? dev_name(dev) : NULL; |
| 55 | struct clk *clk; |
| 56 | |
| 57 | mutex_lock(&clocks_mutex); |
| 58 | clk = clk_find(dev_id, con_id); |
| 59 | if (clk && !__clk_get(clk)) |
| 60 | clk = NULL; |
| 61 | mutex_unlock(&clocks_mutex); |
| 62 | |
| 63 | return clk ? clk : ERR_PTR(-ENOENT); |
| 64 | } |
| 65 | EXPORT_SYMBOL(clk_get); |
| 66 | |
| 67 | void clk_put(struct clk *clk) |
| 68 | { |
| 69 | __clk_put(clk); |
| 70 | } |
| 71 | EXPORT_SYMBOL(clk_put); |
| 72 | |
| 73 | void clkdev_add(struct clk_lookup *cl) |
| 74 | { |
| 75 | mutex_lock(&clocks_mutex); |
| 76 | list_add_tail(&cl->node, &clocks); |
| 77 | mutex_unlock(&clocks_mutex); |
| 78 | } |
| 79 | EXPORT_SYMBOL(clkdev_add); |
| 80 | |
| 81 | #define MAX_DEV_ID 20 |
| 82 | #define MAX_CON_ID 16 |
| 83 | |
| 84 | struct clk_lookup_alloc { |
| 85 | struct clk_lookup cl; |
| 86 | char dev_id[MAX_DEV_ID]; |
| 87 | char con_id[MAX_CON_ID]; |
| 88 | }; |
| 89 | |
| 90 | struct clk_lookup *clkdev_alloc(struct clk *clk, const char *con_id, |
| 91 | const char *dev_fmt, ...) |
| 92 | { |
| 93 | struct clk_lookup_alloc *cla; |
| 94 | |
| 95 | cla = kzalloc(sizeof(*cla), GFP_KERNEL); |
| 96 | if (!cla) |
| 97 | return NULL; |
| 98 | |
| 99 | cla->cl.clk = clk; |
| 100 | if (con_id) { |
| 101 | strlcpy(cla->con_id, con_id, sizeof(cla->con_id)); |
| 102 | cla->cl.con_id = cla->con_id; |
| 103 | } |
| 104 | |
| 105 | if (dev_fmt) { |
| 106 | va_list ap; |
| 107 | |
| 108 | va_start(ap, dev_fmt); |
| 109 | vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap); |
| 110 | cla->cl.dev_id = cla->dev_id; |
| 111 | va_end(ap); |
| 112 | } |
| 113 | |
| 114 | return &cla->cl; |
| 115 | } |
| 116 | EXPORT_SYMBOL(clkdev_alloc); |
| 117 | |
| 118 | /* |
| 119 | * clkdev_drop - remove a clock dynamically allocated |
| 120 | */ |
| 121 | void clkdev_drop(struct clk_lookup *cl) |
| 122 | { |
| 123 | mutex_lock(&clocks_mutex); |
| 124 | list_del(&cl->node); |
| 125 | mutex_unlock(&clocks_mutex); |
| 126 | kfree(cl); |
| 127 | } |
| 128 | EXPORT_SYMBOL(clkdev_drop); |