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Diffstat (limited to 'arch/arm/mach-sa1100/clock.c')
-rw-r--r--arch/arm/mach-sa1100/clock.c132
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 @@
+/*
+ * linux/arch/arm/mach-sa1100/clock.c
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include <linux/clk.h>
+#include <linux/spinlock.h>
+
+#include <asm/hardware.h>
+#include <asm/semaphore.h>
+
+struct clk {
+ struct list_head node;
+ unsigned long rate;
+ struct module *owner;
+ const char *name;
+ unsigned int enabled;
+ void (*enable)(void);
+ void (*disable)(void);
+};
+
+static LIST_HEAD(clocks);
+static DECLARE_MUTEX(clocks_sem);
+static DEFINE_SPINLOCK(clocks_lock);
+
+struct clk *clk_get(struct device *dev, const char *id)
+{
+ struct clk *p, *clk = ERR_PTR(-ENOENT);
+
+ down(&clocks_sem);
+ list_for_each_entry(p, &clocks, node) {
+ if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
+ clk = p;
+ break;
+ }
+ }
+ up(&clocks_sem);
+
+ return clk;
+}
+EXPORT_SYMBOL(clk_get);
+
+void clk_put(struct clk *clk)
+{
+ module_put(clk->owner);
+}
+EXPORT_SYMBOL(clk_put);
+
+int clk_enable(struct clk *clk)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&clocks_lock, flags);
+ if (clk->enabled++ == 0)
+ clk->enable();
+ spin_unlock_irqrestore(&clocks_lock, flags);
+ return 0;
+}
+EXPORT_SYMBOL(clk_enable);
+
+void clk_disable(struct clk *clk)
+{
+ unsigned long flags;
+
+ WARN_ON(clk->enabled == 0);
+
+ spin_lock_irqsave(&clocks_lock, flags);
+ if (--clk->enabled == 0)
+ clk->disable();
+ spin_unlock_irqrestore(&clocks_lock, flags);
+}
+EXPORT_SYMBOL(clk_disable);
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+ return clk->rate;
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+
+static void clk_gpio27_enable(void)
+{
+ /*
+ * First, set up the 3.6864MHz clock on GPIO 27 for the SA-1111:
+ * (SA-1110 Developer's Manual, section 9.1.2.1)
+ */
+ GAFR |= GPIO_32_768kHz;
+ GPDR |= GPIO_32_768kHz;
+ TUCR = TUCR_3_6864MHz;
+}
+
+static void clk_gpio27_disable(void)
+{
+ TUCR = 0;
+ GPDR &= ~GPIO_32_768kHz;
+ GAFR &= ~GPIO_32_768kHz;
+}
+
+static struct clk clk_gpio27 = {
+ .name = "GPIO27_CLK",
+ .rate = 3686400,
+ .enable = clk_gpio27_enable,
+ .disable = clk_gpio27_disable,
+};
+
+int clk_register(struct clk *clk)
+{
+ down(&clocks_sem);
+ list_add(&clk->node, &clocks);
+ up(&clocks_sem);
+ return 0;
+}
+EXPORT_SYMBOL(clk_register);
+
+void clk_unregister(struct clk *clk)
+{
+ down(&clocks_sem);
+ list_del(&clk->node);
+ up(&clocks_sem);
+}
+EXPORT_SYMBOL(clk_unregister);
+
+static int __init clk_init(void)
+{
+ clk_register(&clk_gpio27);
+ return 0;
+}
+arch_initcall(clk_init);