MIPS: JZ4740: Add clock API support.

Add support for managing the clocks found on JZ4740 SoC through the
Linux clock API.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1466/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 109 insertions, 0 deletions

diff --git a/arch/mips/jz4740/clock-debugfs.c b/arch/mips/jz4740/clock-debugfs.c
new file mode 100644
index 000000000000..330a0f2bf17b
--- /dev/null
+++ b/arch/mips/jz4740/clock-debugfs.c
@@ -0,0 +1,109 @@
+/*
+ *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *  JZ4740 SoC clock support debugfs entries
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under  the terms of the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+
+#include <asm/mach-jz4740/clock.h>
+#include "clock.h"
+
+static struct dentry *jz4740_clock_debugfs;
+
+static int jz4740_clock_debugfs_show_enabled(void *data, uint64_t *value)
+{
+        struct clk *clk = data;
+        *value = clk_is_enabled(clk);
+
+        return 0;
+}
+
+static int jz4740_clock_debugfs_set_enabled(void *data, uint64_t value)
+{
+        struct clk *clk = data;
+
+        if (value)
+                return clk_enable(clk);
+        else
+                clk_disable(clk);
+
+        return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(jz4740_clock_debugfs_ops_enabled,
+        jz4740_clock_debugfs_show_enabled,
+        jz4740_clock_debugfs_set_enabled,
+        "%llu\n");
+
+static int jz4740_clock_debugfs_show_rate(void *data, uint64_t *value)
+{
+        struct clk *clk = data;
+        *value = clk_get_rate(clk);
+
+        return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(jz4740_clock_debugfs_ops_rate,
+        jz4740_clock_debugfs_show_rate,
+        NULL,
+        "%llu\n");
+
+void jz4740_clock_debugfs_add_clk(struct clk *clk)
+{
+        if (!jz4740_clock_debugfs)
+                return;
+
+        clk->debugfs_entry = debugfs_create_dir(clk->name, jz4740_clock_debugfs);
+        debugfs_create_file("rate", S_IWUGO | S_IRUGO, clk->debugfs_entry, clk,
+                                &jz4740_clock_debugfs_ops_rate);
+        debugfs_create_file("enabled", S_IRUGO, clk->debugfs_entry, clk,
+                                &jz4740_clock_debugfs_ops_enabled);
+
+        if (clk->parent) {
+                char parent_path[100];
+                snprintf(parent_path, 100, "../%s", clk->parent->name);
+                clk->debugfs_parent_entry = debugfs_create_symlink("parent",
+                                                clk->debugfs_entry,
+                                                parent_path);
+        }
+}
+
+/* TODO: Locking */
+void jz4740_clock_debugfs_update_parent(struct clk *clk)
+{
+        if (clk->debugfs_parent_entry)
+                debugfs_remove(clk->debugfs_parent_entry);
+
+        if (clk->parent) {
+                char parent_path[100];
+                snprintf(parent_path, 100, "../%s", clk->parent->name);
+                clk->debugfs_parent_entry = debugfs_create_symlink("parent",
+                                                clk->debugfs_entry,
+                                                parent_path);
+        } else {
+                clk->debugfs_parent_entry = NULL;
+        }
+}
+
+void jz4740_clock_debugfs_init(void)
+{
+        jz4740_clock_debugfs = debugfs_create_dir("jz4740-clock", NULL);
+        if (IS_ERR(jz4740_clock_debugfs))
+                jz4740_clock_debugfs = NULL;
+}