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+/*
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+ * Copyright 2013 Emilio López
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+ *
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+ * Emilio López <emilio@elopez.com.ar>
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+ *
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+ * This program is free software; you can redistribute it and/or modify
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+ * it under the terms of the GNU General Public License as published by
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+ * the Free Software Foundation; either version 2 of the License, or
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+ * (at your option) any later version.
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+ *
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+ * This program is distributed in the hope that it will be useful,
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+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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+ * GNU General Public License for more details.
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+ */
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+
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+#include <linux/clk-provider.h>
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+#include <linux/clkdev.h>
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+
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+#include "clk-factors.h"
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+
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+/**
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+ * sun4i_get_mod0_factors() - calculates m, n factors for MOD0-style clocks
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+ * MOD0 rate is calculated as follows
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+ * rate = (parent_rate >> p) / (m + 1);
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+ */
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+
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+static void sun4i_a10_get_mod0_factors(u32 *freq, u32 parent_rate,
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+ u8 *n, u8 *k, u8 *m, u8 *p)
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+{
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+ u8 div, calcm, calcp;
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+
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+ /* These clocks can only divide, so we will never be able to achieve
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+ * frequencies higher than the parent frequency */
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+ if (*freq > parent_rate)
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+ *freq = parent_rate;
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+
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+ div = DIV_ROUND_UP(parent_rate, *freq);
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+
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+ if (div < 16)
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+ calcp = 0;
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+ else if (div / 2 < 16)
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+ calcp = 1;
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+ else if (div / 4 < 16)
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+ calcp = 2;
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+ else
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+ calcp = 3;
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+
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+ calcm = DIV_ROUND_UP(div, 1 << calcp);
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+
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+ *freq = (parent_rate >> calcp) / calcm;
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+
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+ /* we were called to round the frequency, we can now return */
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+ if (n == NULL)
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+ return;
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+
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+ *m = calcm - 1;
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+ *p = calcp;
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+}
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+
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+/* user manual says "n" but it's really "p" */
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+static struct clk_factors_config sun4i_a10_mod0_config = {
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+ .mshift = 0,
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+ .mwidth = 4,
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+ .pshift = 16,
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+ .pwidth = 2,
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+};
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+
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+static const struct factors_data sun4i_a10_mod0_data __initconst = {
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+ .enable = 31,
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+ .mux = 24,
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+ .table = &sun4i_a10_mod0_config,
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+ .getter = sun4i_a10_get_mod0_factors,
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+};
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+
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+static DEFINE_SPINLOCK(sun4i_a10_mod0_lock);
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+
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+static void __init sun4i_a10_mod0_setup(struct device_node *node)
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+{
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+ sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun4i_a10_mod0_lock);
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+}
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+CLK_OF_DECLARE(sun4i_a10_mod0, "allwinner,sun4i-a10-mod0-clk", sun4i_a10_mod0_setup);
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