diff options
Diffstat (limited to 'arch/arm/plat-tcc/clock.c')
| -rw-r--r-- | arch/arm/plat-tcc/clock.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/arch/arm/plat-tcc/clock.c b/arch/arm/plat-tcc/clock.c new file mode 100644 index 00000000000..f3ced10d527 --- /dev/null +++ b/arch/arm/plat-tcc/clock.c | |||
| @@ -0,0 +1,179 @@ | |||
| 1 | /* | ||
| 2 | * Clock framework for Telechips SoCs | ||
| 3 | * Based on arch/arm/plat-mxc/clock.c | ||
| 4 | * | ||
| 5 | * Copyright (C) 2004 - 2005 Nokia corporation | ||
| 6 | * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com> | ||
| 7 | * Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com> | ||
| 8 | * Copyright 2007 Freescale Semiconductor, Inc. All Rights Reserved. | ||
| 9 | * Copyright 2008 Juergen Beisert, kernel@pengutronix.de | ||
| 10 | * Copyright 2010 Hans J. Koch, hjk@linutronix.de | ||
| 11 | * | ||
| 12 | * Licensed under the terms of the GPL v2. | ||
| 13 | */ | ||
| 14 | |||
| 15 | #include <linux/clk.h> | ||
| 16 | #include <linux/err.h> | ||
| 17 | #include <linux/errno.h> | ||
| 18 | #include <linux/module.h> | ||
| 19 | #include <linux/mutex.h> | ||
| 20 | #include <linux/string.h> | ||
| 21 | |||
| 22 | #include <mach/clock.h> | ||
| 23 | #include <mach/hardware.h> | ||
| 24 | |||
| 25 | static DEFINE_MUTEX(clocks_mutex); | ||
| 26 | |||
| 27 | /*------------------------------------------------------------------------- | ||
| 28 | * Standard clock functions defined in include/linux/clk.h | ||
| 29 | *-------------------------------------------------------------------------*/ | ||
| 30 | |||
| 31 | static void __clk_disable(struct clk *clk) | ||
| 32 | { | ||
| 33 | BUG_ON(clk->refcount == 0); | ||
| 34 | |||
| 35 | if (!(--clk->refcount) && clk->disable) { | ||
| 36 | /* Unconditionally disable the clock in hardware */ | ||
| 37 | clk->disable(clk); | ||
| 38 | /* recursively disable parents */ | ||
| 39 | if (clk->parent) | ||
| 40 | __clk_disable(clk->parent); | ||
| 41 | } | ||
| 42 | } | ||
| 43 | |||
| 44 | static int __clk_enable(struct clk *clk) | ||
| 45 | { | ||
| 46 | int ret = 0; | ||
| 47 | |||
| 48 | if (clk->refcount++ == 0 && clk->enable) { | ||
| 49 | if (clk->parent) | ||
| 50 | ret = __clk_enable(clk->parent); | ||
| 51 | if (ret) | ||
| 52 | return ret; | ||
| 53 | else | ||
| 54 | return clk->enable(clk); | ||
| 55 | } | ||
| 56 | |||
| 57 | return 0; | ||
| 58 | } | ||
| 59 | |||
| 60 | /* This function increments the reference count on the clock and enables the | ||
| 61 | * clock if not already enabled. The parent clock tree is recursively enabled | ||
| 62 | */ | ||
| 63 | int clk_enable(struct clk *clk) | ||
| 64 | { | ||
| 65 | int ret = 0; | ||
| 66 | |||
| 67 | if (!clk) | ||
| 68 | return -EINVAL; | ||
| 69 | |||
| 70 | mutex_lock(&clocks_mutex); | ||
| 71 | ret = __clk_enable(clk); | ||
| 72 | mutex_unlock(&clocks_mutex); | ||
| 73 | |||
| 74 | return ret; | ||
| 75 | } | ||
| 76 | EXPORT_SYMBOL_GPL(clk_enable); | ||
| 77 | |||
| 78 | /* This function decrements the reference count on the clock and disables | ||
| 79 | * the clock when reference count is 0. The parent clock tree is | ||
| 80 | * recursively disabled | ||
| 81 | */ | ||
| 82 | void clk_disable(struct clk *clk) | ||
| 83 | { | ||
| 84 | if (!clk) | ||
| 85 | return; | ||
| 86 | |||
| 87 | mutex_lock(&clocks_mutex); | ||
| 88 | __clk_disable(clk); | ||
| 89 | mutex_unlock(&clocks_mutex); | ||
| 90 | } | ||
| 91 | EXPORT_SYMBOL_GPL(clk_disable); | ||
| 92 | |||
| 93 | /* Retrieve the *current* clock rate. If the clock itself | ||
| 94 | * does not provide a special calculation routine, ask | ||
| 95 | * its parent and so on, until one is able to return | ||
| 96 | * a valid clock rate | ||
| 97 | */ | ||
| 98 | unsigned long clk_get_rate(struct clk *clk) | ||
| 99 | { | ||
| 100 | if (!clk) | ||
| 101 | return 0UL; | ||
| 102 | |||
| 103 | if (clk->get_rate) | ||
| 104 | return clk->get_rate(clk); | ||
| 105 | |||
| 106 | return clk_get_rate(clk->parent); | ||
| 107 | } | ||
| 108 | EXPORT_SYMBOL_GPL(clk_get_rate); | ||
| 109 | |||
| 110 | /* Round the requested clock rate to the nearest supported | ||
| 111 | * rate that is less than or equal to the requested rate. | ||
| 112 | * This is dependent on the clock's current parent. | ||
| 113 | */ | ||
| 114 | long clk_round_rate(struct clk *clk, unsigned long rate) | ||
| 115 | { | ||
| 116 | if (!clk) | ||
| 117 | return 0; | ||
| 118 | if (!clk->round_rate) | ||
| 119 | return 0; | ||
| 120 | |||
| 121 | return clk->round_rate(clk, rate); | ||
| 122 | } | ||
| 123 | EXPORT_SYMBOL_GPL(clk_round_rate); | ||
| 124 | |||
| 125 | /* Set the clock to the requested clock rate. The rate must | ||
| 126 | * match a supported rate exactly based on what clk_round_rate returns | ||
| 127 | */ | ||
| 128 | int clk_set_rate(struct clk *clk, unsigned long rate) | ||
| 129 | { | ||
| 130 | int ret = -EINVAL; | ||
| 131 | |||
| 132 | if (!clk) | ||
| 133 | return ret; | ||
| 134 | if (!clk->set_rate || !rate) | ||
| 135 | return ret; | ||
| 136 | |||
| 137 | mutex_lock(&clocks_mutex); | ||
| 138 | ret = clk->set_rate(clk, rate); | ||
| 139 | mutex_unlock(&clocks_mutex); | ||
| 140 | |||
| 141 | return ret; | ||
| 142 | } | ||
| 143 | EXPORT_SYMBOL_GPL(clk_set_rate); | ||
| 144 | |||
| 145 | /* Set the clock's parent to another clock source */ | ||
| 146 | int clk_set_parent(struct clk *clk, struct clk *parent) | ||
| 147 | { | ||
| 148 | struct clk *old; | ||
| 149 | int ret = -EINVAL; | ||
| 150 | |||
| 151 | if (!clk) | ||
| 152 | return ret; | ||
| 153 | if (!clk->set_parent || !parent) | ||
| 154 | return ret; | ||
| 155 | |||
| 156 | mutex_lock(&clocks_mutex); | ||
| 157 | old = clk->parent; | ||
| 158 | if (clk->refcount) | ||
| 159 | __clk_enable(parent); | ||
| 160 | ret = clk->set_parent(clk, parent); | ||
| 161 | if (ret) | ||
| 162 | old = parent; | ||
| 163 | if (clk->refcount) | ||
| 164 | __clk_disable(old); | ||
| 165 | mutex_unlock(&clocks_mutex); | ||
| 166 | |||
| 167 | return ret; | ||
| 168 | } | ||
| 169 | EXPORT_SYMBOL_GPL(clk_set_parent); | ||
| 170 | |||
| 171 | /* Retrieve the clock's parent clock source */ | ||
| 172 | struct clk *clk_get_parent(struct clk *clk) | ||
| 173 | { | ||
| 174 | if (!clk) | ||
| 175 | return NULL; | ||
| 176 | |||
| 177 | return clk->parent; | ||
| 178 | } | ||
| 179 | EXPORT_SYMBOL_GPL(clk_get_parent); | ||
