ns9xxx: add clock api

Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>

3 files changed, 251 insertions, 1 deletions

diff --git a/arch/arm/mach-ns9xxx/Makefile b/arch/arm/mach-ns9xxx/Makefile
index 67a9e30c8789..41efaf9ad50b 100644
--- a/arch/arm/mach-ns9xxx/Makefile
+++ b/arch/arm/mach-ns9xxx/Makefile
@@ -1,4 +1,4 @@
-obj-y := irq.o generic.o gpio.o
+obj-y := clock.o generic.o gpio.o irq.o
 
 obj-$(CONFIG_MACH_CC9P9360DEV) += mach-cc9p9360dev.o
 obj-$(CONFIG_MACH_CC9P9360JS) += mach-cc9p9360js.o
diff --git a/arch/arm/mach-ns9xxx/clock.c b/arch/arm/mach-ns9xxx/clock.c
new file mode 100644
index 000000000000..f8639161068f
--- /dev/null
+++ b/arch/arm/mach-ns9xxx/clock.c
@@ -0,0 +1,215 @@
+/*
+ * arch/arm/mach-ns9xxx/clock.c
+ *
+ * Copyright (C) 2007 by Digi International Inc.
+ * All rights reserved.
+ *
+ * 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.
+ */
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/clk.h>
+#include <linux/string.h>
+#include <linux/platform_device.h>
+
+#include <asm/semaphore.h>
+#include "clock.h"
+
+static LIST_HEAD(clocks);
+static DEFINE_SPINLOCK(clk_lock);
+
+struct clk *clk_get(struct device *dev, const char *id)
+{
+        struct clk *p, *ret = NULL, *retgen = NULL;
+        unsigned long flags;
+        int idno;
+
+        if (dev == NULL || dev->bus != &platform_bus_type)
+                idno = -1;
+        else
+                idno = to_platform_device(dev)->id;
+
+        spin_lock_irqsave(&clk_lock, flags);
+        list_for_each_entry(p, &clocks, node) {
+                if (strcmp(id, p->name) == 0) {
+                        if (p->id == idno) {
+                                if (!try_module_get(p->owner))
+                                        continue;
+                                ret = p;
+                                break;
+                        } else if (p->id == -1)
+                                /* remember match with id == -1 in case there is
+                                 * no clock for idno */
+                                retgen = p;
+                }
+        }
+
+        if (!ret && retgen && try_module_get(retgen->owner))
+                ret = retgen;
+
+        if (ret)
+                ++ret->refcount;
+
+        spin_unlock_irqrestore(&clk_lock, flags);
+
+        return ret ? ret : ERR_PTR(-ENOENT);
+}
+EXPORT_SYMBOL(clk_get);
+
+void clk_put(struct clk *clk)
+{
+        module_put(clk->owner);
+        --clk->refcount;
+}
+EXPORT_SYMBOL(clk_put);
+
+static int clk_enable_unlocked(struct clk *clk)
+{
+        int ret = 0;
+        if (clk->parent) {
+                ret = clk_enable_unlocked(clk->parent);
+                if (ret)
+                        return ret;
+        }
+
+        if (clk->usage++ == 0 && clk->endisable)
+                ret = clk->endisable(clk, 1);
+
+        return ret;
+}
+
+int clk_enable(struct clk *clk)
+{
+        int ret;
+        unsigned long flags;
+
+        spin_lock_irqsave(&clk_lock, flags);
+
+        ret = clk_enable_unlocked(clk);
+
+        spin_unlock_irqrestore(&clk_lock, flags);
+
+        return ret;
+}
+EXPORT_SYMBOL(clk_enable);
+
+static void clk_disable_unlocked(struct clk *clk)
+{
+        if (--clk->usage == 0 && clk->endisable)
+                clk->endisable(clk, 0);
+
+        if (clk->parent)
+                clk_disable_unlocked(clk->parent);
+}
+
+void clk_disable(struct clk *clk)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&clk_lock, flags);
+
+        clk_disable_unlocked(clk);
+
+        spin_unlock_irqrestore(&clk_lock, flags);
+}
+EXPORT_SYMBOL(clk_disable);
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+        if (clk->get_rate)
+                return clk->get_rate(clk);
+
+        if (clk->rate)
+                return clk->rate;
+
+        if (clk->parent)
+                return clk_get_rate(clk->parent);
+
+        return 0;
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+int clk_register(struct clk *clk)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&clk_lock, flags);
+
+        list_add(&clk->node, &clocks);
+
+        if (clk->parent)
+                ++clk->parent->refcount;
+
+        spin_unlock_irqrestore(&clk_lock, flags);
+
+        return 0;
+}
+
+int clk_unregister(struct clk *clk)
+{
+        int ret = 0;
+        unsigned long flags;
+
+        spin_lock_irqsave(&clk_lock, flags);
+
+        if (clk->usage || clk->refcount)
+                ret = -EBUSY;
+        else
+                list_del(&clk->node);
+
+        if (clk->parent)
+                --clk->parent->refcount;
+
+        spin_unlock_irqrestore(&clk_lock, flags);
+
+        return ret;
+}
+
+#if defined CONFIG_DEBUG_FS
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+static int clk_debugfs_show(struct seq_file *s, void *null)
+{
+        unsigned long flags;
+        struct clk *p;
+
+        spin_lock_irqsave(&clk_lock, flags);
+
+        list_for_each_entry(p, &clocks, node)
+                seq_printf(s, "%s.%d: usage=%lu refcount=%lu rate=%lu\n",
+                                p->name, p->id, p->usage, p->refcount,
+                                p->usage ? clk_get_rate(p) : 0);
+
+        spin_unlock_irqrestore(&clk_lock, flags);
+
+        return 0;
+}
+
+static int clk_debugfs_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, clk_debugfs_show, NULL);
+}
+
+static struct file_operations clk_debugfs_operations = {
+        .open = clk_debugfs_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = single_release,
+};
+
+static int __init clk_debugfs_init(void)
+{
+        struct dentry *dentry;
+
+        dentry = debugfs_create_file("clk", S_IFREG | S_IRUGO, NULL, NULL,
+                        &clk_debugfs_operations);
+        return IS_ERR(dentry) ? PTR_ERR(dentry) : 0;
+}
+subsys_initcall(clk_debugfs_init);
+
+#endif /* if defined CONFIG_DEBUG_FS */
diff --git a/arch/arm/mach-ns9xxx/clock.h b/arch/arm/mach-ns9xxx/clock.h
new file mode 100644
index 000000000000..b86c30dd79eb
--- /dev/null
+++ b/arch/arm/mach-ns9xxx/clock.h
@@ -0,0 +1,35 @@
+/*
+ * arch/arm/mach-ns9xxx/clock.h
+ *
+ * Copyright (C) 2007 by Digi International Inc.
+ * All rights reserved.
+ *
+ * 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.
+ */
+#ifndef __NS9XXX_CLOCK_H
+#define __NS9XXX_CLOCK_H
+
+#include <linux/list.h>
+
+struct clk {
+        struct module *owner;
+        const char *name;
+        int id;
+
+        struct clk *parent;
+
+        unsigned long rate;
+        int (*endisable)(struct clk *, int enable);
+        unsigned long (*get_rate)(struct clk *);
+
+        struct list_head node;
+        unsigned long refcount;
+        unsigned long usage;
+};
+
+int clk_register(struct clk *clk);
+int clk_unregister(struct clk *clk);
+
+#endif /* ifndef __NS9XXX_CLOCK_H */