clk: sunxi-ng: Add fractional lib

Some clocks can be switched to a mode called fractional that have two fixed
output rate you can choose from.

Add a small library to deal with those clocks.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20160629190535.11855-4-maxime.ripard@free-electrons.com
diff --git a/drivers/clk/sunxi-ng/ccu_frac.h b/drivers/clk/sunxi-ng/ccu_frac.h
new file mode 100644
index 0000000..e4c670b
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_frac.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2016 Maxime Ripard. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _CCU_FRAC_H_
+#define _CCU_FRAC_H_
+
+#include <linux/clk-provider.h>
+
+#include "ccu_common.h"
+
+struct _ccu_frac {
+	u32		enable;
+	u32		select;
+
+	unsigned long	rates[2];
+};
+
+#define _SUNXI_CCU_FRAC(_enable, _select, _rate1, _rate2)		\
+	{								\
+		.enable	= _enable,					\
+		.select	= _select,					\
+		.rates = { _rate1, _rate2 },				\
+	}
+
+bool ccu_frac_helper_is_enabled(struct ccu_common *common,
+				struct _ccu_frac *cf);
+void ccu_frac_helper_enable(struct ccu_common *common,
+			    struct _ccu_frac *cf);
+void ccu_frac_helper_disable(struct ccu_common *common,
+			     struct _ccu_frac *cf);
+
+bool ccu_frac_helper_has_rate(struct ccu_common *common,
+			      struct _ccu_frac *cf,
+			      unsigned long rate);
+
+unsigned long ccu_frac_helper_read_rate(struct ccu_common *common,
+					struct _ccu_frac *cf);
+
+int ccu_frac_helper_set_rate(struct ccu_common *common,
+			     struct _ccu_frac *cf,
+			     unsigned long rate);
+
+#endif /* _CCU_FRAC_H_ */