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-rw-r--r--drivers/sh/clk.c91
-rw-r--r--include/linux/sh_clk.h10
2 files changed, 99 insertions, 2 deletions
diff --git a/drivers/sh/clk.c b/drivers/sh/clk.c
index 661a801126ad..813d97cdad49 100644
--- a/drivers/sh/clk.c
+++ b/drivers/sh/clk.c
@@ -25,7 +25,7 @@
#include <linux/sysdev.h>
#include <linux/seq_file.h>
#include <linux/err.h>
-#include <linux/platform_device.h>
+#include <linux/io.h>
#include <linux/debugfs.h>
#include <linux/cpufreq.h>
#include <linux/clk.h>
@@ -251,8 +251,88 @@ void recalculate_root_clocks(void)
}
}
+static struct clk_mapping dummy_mapping;
+
+static struct clk *lookup_root_clock(struct clk *clk)
+{
+ while (clk->parent)
+ clk = clk->parent;
+
+ return clk;
+}
+
+static int clk_establish_mapping(struct clk *clk)
+{
+ struct clk_mapping *mapping = clk->mapping;
+
+ /*
+ * Propagate mappings.
+ */
+ if (!mapping) {
+ struct clk *clkp;
+
+ /*
+ * dummy mapping for root clocks with no specified ranges
+ */
+ if (!clk->parent) {
+ clk->mapping = &dummy_mapping;
+ return 0;
+ }
+
+ /*
+ * If we're on a child clock and it provides no mapping of its
+ * own, inherit the mapping from its root clock.
+ */
+ clkp = lookup_root_clock(clk);
+ mapping = clkp->mapping;
+ BUG_ON(!mapping);
+ }
+
+ /*
+ * Establish initial mapping.
+ */
+ if (!mapping->base && mapping->phys) {
+ kref_init(&mapping->ref);
+
+ mapping->base = ioremap_nocache(mapping->phys, mapping->len);
+ if (unlikely(!mapping->base))
+ return -ENXIO;
+ } else if (mapping->base) {
+ /*
+ * Bump the refcount for an existing mapping
+ */
+ kref_get(&mapping->ref);
+ }
+
+ clk->mapping = mapping;
+ return 0;
+}
+
+static void clk_destroy_mapping(struct kref *kref)
+{
+ struct clk_mapping *mapping;
+
+ mapping = container_of(kref, struct clk_mapping, ref);
+
+ iounmap(mapping->base);
+}
+
+static void clk_teardown_mapping(struct clk *clk)
+{
+ struct clk_mapping *mapping = clk->mapping;
+
+ /* Nothing to do */
+ if (mapping == &dummy_mapping)
+ return;
+
+ kref_put(&mapping->ref, clk_destroy_mapping);
+ clk->mapping = NULL;
+}
+
int clk_register(struct clk *clk)
{
+ int ret;
+
if (clk == NULL || IS_ERR(clk))
return -EINVAL;
@@ -267,6 +347,10 @@ int clk_register(struct clk *clk)
INIT_LIST_HEAD(&clk->children);
clk->usecount = 0;
+ ret = clk_establish_mapping(clk);
+ if (unlikely(ret))
+ goto out_unlock;
+
if (clk->parent)
list_add(&clk->sibling, &clk->parent->children);
else
@@ -275,9 +359,11 @@ int clk_register(struct clk *clk)
list_add(&clk->node, &clock_list);
if (clk->ops && clk->ops->init)
clk->ops->init(clk);
+
+out_unlock:
mutex_unlock(&clock_list_sem);
- return 0;
+ return ret;
}
EXPORT_SYMBOL_GPL(clk_register);
@@ -286,6 +372,7 @@ void clk_unregister(struct clk *clk)
mutex_lock(&clock_list_sem);
list_del(&clk->sibling);
list_del(&clk->node);
+ clk_teardown_mapping(clk);
mutex_unlock(&clock_list_sem);
}
EXPORT_SYMBOL_GPL(clk_unregister);
diff --git a/include/linux/sh_clk.h b/include/linux/sh_clk.h
index ecdfea54a49e..8ae37707a4a4 100644
--- a/include/linux/sh_clk.h
+++ b/include/linux/sh_clk.h
@@ -4,11 +4,20 @@
#include <linux/list.h>
#include <linux/seq_file.h>
#include <linux/cpufreq.h>
+#include <linux/types.h>
+#include <linux/kref.h>
#include <linux/clk.h>
#include <linux/err.h>
struct clk;
+struct clk_mapping {
+ phys_addr_t phys;
+ void __iomem *base;
+ unsigned long len;
+ struct kref ref;
+};
+
struct clk_ops {
void (*init)(struct clk *clk);
int (*enable)(struct clk *clk);
@@ -42,6 +51,7 @@ struct clk {
unsigned long arch_flags;
void *priv;
struct dentry *dentry;
+ struct clk_mapping *mapping;
struct cpufreq_frequency_table *freq_table;
};