diff options
Diffstat (limited to 'arch/arm/mach-sa1100/clock.c')
| -rw-r--r-- | arch/arm/mach-sa1100/clock.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/arch/arm/mach-sa1100/clock.c b/arch/arm/mach-sa1100/clock.c new file mode 100644 index 000000000000..b1e8fd766c1a --- /dev/null +++ b/arch/arm/mach-sa1100/clock.c | |||
| @@ -0,0 +1,132 @@ | |||
| 1 | /* | ||
| 2 | * linux/arch/arm/mach-sa1100/clock.c | ||
| 3 | */ | ||
| 4 | #include <linux/module.h> | ||
| 5 | #include <linux/kernel.h> | ||
| 6 | #include <linux/list.h> | ||
| 7 | #include <linux/errno.h> | ||
| 8 | #include <linux/err.h> | ||
| 9 | #include <linux/string.h> | ||
| 10 | #include <linux/clk.h> | ||
| 11 | #include <linux/spinlock.h> | ||
| 12 | |||
| 13 | #include <asm/hardware.h> | ||
| 14 | #include <asm/semaphore.h> | ||
| 15 | |||
| 16 | struct clk { | ||
| 17 | struct list_head node; | ||
| 18 | unsigned long rate; | ||
| 19 | struct module *owner; | ||
| 20 | const char *name; | ||
| 21 | unsigned int enabled; | ||
| 22 | void (*enable)(void); | ||
| 23 | void (*disable)(void); | ||
| 24 | }; | ||
| 25 | |||
| 26 | static LIST_HEAD(clocks); | ||
| 27 | static DECLARE_MUTEX(clocks_sem); | ||
| 28 | static DEFINE_SPINLOCK(clocks_lock); | ||
| 29 | |||
| 30 | struct clk *clk_get(struct device *dev, const char *id) | ||
| 31 | { | ||
| 32 | struct clk *p, *clk = ERR_PTR(-ENOENT); | ||
| 33 | |||
| 34 | down(&clocks_sem); | ||
| 35 | list_for_each_entry(p, &clocks, node) { | ||
| 36 | if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) { | ||
| 37 | clk = p; | ||
| 38 | break; | ||
| 39 | } | ||
| 40 | } | ||
| 41 | up(&clocks_sem); | ||
| 42 | |||
| 43 | return clk; | ||
| 44 | } | ||
| 45 | EXPORT_SYMBOL(clk_get); | ||
| 46 | |||
| 47 | void clk_put(struct clk *clk) | ||
| 48 | { | ||
| 49 | module_put(clk->owner); | ||
| 50 | } | ||
| 51 | EXPORT_SYMBOL(clk_put); | ||
| 52 | |||
| 53 | int clk_enable(struct clk *clk) | ||
| 54 | { | ||
| 55 | unsigned long flags; | ||
| 56 | |||
| 57 | spin_lock_irqsave(&clocks_lock, flags); | ||
| 58 | if (clk->enabled++ == 0) | ||
| 59 | clk->enable(); | ||
| 60 | spin_unlock_irqrestore(&clocks_lock, flags); | ||
| 61 | return 0; | ||
| 62 | } | ||
| 63 | EXPORT_SYMBOL(clk_enable); | ||
| 64 | |||
| 65 | void clk_disable(struct clk *clk) | ||
| 66 | { | ||
| 67 | unsigned long flags; | ||
| 68 | |||
| 69 | WARN_ON(clk->enabled == 0); | ||
| 70 | |||
| 71 | spin_lock_irqsave(&clocks_lock, flags); | ||
| 72 | if (--clk->enabled == 0) | ||
| 73 | clk->disable(); | ||
| 74 | spin_unlock_irqrestore(&clocks_lock, flags); | ||
| 75 | } | ||
| 76 | EXPORT_SYMBOL(clk_disable); | ||
| 77 | |||
| 78 | unsigned long clk_get_rate(struct clk *clk) | ||
| 79 | { | ||
| 80 | return clk->rate; | ||
| 81 | } | ||
| 82 | EXPORT_SYMBOL(clk_get_rate); | ||
| 83 | |||
| 84 | |||
| 85 | static void clk_gpio27_enable(void) | ||
| 86 | { | ||
| 87 | /* | ||
| 88 | * First, set up the 3.6864MHz clock on GPIO 27 for the SA-1111: | ||
| 89 | * (SA-1110 Developer's Manual, section 9.1.2.1) | ||
| 90 | */ | ||
| 91 | GAFR |= GPIO_32_768kHz; | ||
| 92 | GPDR |= GPIO_32_768kHz; | ||
| 93 | TUCR = TUCR_3_6864MHz; | ||
| 94 | } | ||
| 95 | |||
| 96 | static void clk_gpio27_disable(void) | ||
| 97 | { | ||
| 98 | TUCR = 0; | ||
| 99 | GPDR &= ~GPIO_32_768kHz; | ||
| 100 | GAFR &= ~GPIO_32_768kHz; | ||
| 101 | } | ||
| 102 | |||
| 103 | static struct clk clk_gpio27 = { | ||
| 104 | .name = "GPIO27_CLK", | ||
| 105 | .rate = 3686400, | ||
| 106 | .enable = clk_gpio27_enable, | ||
| 107 | .disable = clk_gpio27_disable, | ||
| 108 | }; | ||
| 109 | |||
| 110 | int clk_register(struct clk *clk) | ||
| 111 | { | ||
| 112 | down(&clocks_sem); | ||
| 113 | list_add(&clk->node, &clocks); | ||
| 114 | up(&clocks_sem); | ||
| 115 | return 0; | ||
| 116 | } | ||
| 117 | EXPORT_SYMBOL(clk_register); | ||
| 118 | |||
| 119 | void clk_unregister(struct clk *clk) | ||
| 120 | { | ||
| 121 | down(&clocks_sem); | ||
| 122 | list_del(&clk->node); | ||
| 123 | up(&clocks_sem); | ||
| 124 | } | ||
| 125 | EXPORT_SYMBOL(clk_unregister); | ||
| 126 | |||
| 127 | static int __init clk_init(void) | ||
| 128 | { | ||
| 129 | clk_register(&clk_gpio27); | ||
| 130 | return 0; | ||
| 131 | } | ||
| 132 | arch_initcall(clk_init); | ||
