1 files changed, 82 insertions, 0 deletions
diff --git a/drivers/clk/sunxi/clk-mod0.c b/drivers/clk/sunxi/clk-mod0.c
new file mode 100644
index 00000000000..bce09a84ab4
--- /dev/null
+++ b/drivers/clk/sunxi/clk-mod0.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright 2013 Emilio López
+ *
+ * Emilio López <emilio@elopez.com.ar>
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+
+#include "clk-factors.h"
+
+/**
+ * sun4i_get_mod0_factors() - calculates m, n factors for MOD0-style clocks
+ * MOD0 rate is calculated as follows
+ * rate = (parent_rate >> p) / (m + 1);
+ */
+
+static void sun4i_a10_get_mod0_factors(u32 *freq, u32 parent_rate,
+				       u8 *n, u8 *k, u8 *m, u8 *p)
+{
+	u8 div, calcm, calcp;
+
+	/* These clocks can only divide, so we will never be able to achieve
+	 * frequencies higher than the parent frequency */
+	if (*freq > parent_rate)
+		*freq = parent_rate;
+
+	div = DIV_ROUND_UP(parent_rate, *freq);
+
+	if (div < 16)
+		calcp = 0;
+	else if (div / 2 < 16)
+		calcp = 1;
+	else if (div / 4 < 16)
+		calcp = 2;
+	else
+		calcp = 3;
+
+	calcm = DIV_ROUND_UP(div, 1 << calcp);
+
+	*freq = (parent_rate >> calcp) / calcm;
+
+	/* we were called to round the frequency, we can now return */
+	if (n == NULL)
+		return;
+
+	*m = calcm - 1;
+	*p = calcp;
+}
+
+/* user manual says "n" but it's really "p" */
+static struct clk_factors_config sun4i_a10_mod0_config = {
+	.mshift = 0,
+	.mwidth = 4,
+	.pshift = 16,
+	.pwidth = 2,
+};
+
+static const struct factors_data sun4i_a10_mod0_data __initconst = {
+	.enable = 31,
+	.mux = 24,
+	.table = &sun4i_a10_mod0_config,
+	.getter = sun4i_a10_get_mod0_factors,
+};
+
+static DEFINE_SPINLOCK(sun4i_a10_mod0_lock);
+
+static void __init sun4i_a10_mod0_setup(struct device_node *node)
+{
+	sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun4i_a10_mod0_lock);
+}
+CLK_OF_DECLARE(sun4i_a10_mod0, "allwinner,sun4i-a10-mod0-clk", sun4i_a10_mod0_setup);