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/*
* 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);
static DEFINE_SPINLOCK(sun5i_a13_mbus_lock);
static void __init sun5i_a13_mbus_setup(struct device_node *node)
{
struct clk *mbus = sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun5i_a13_mbus_lock);
/* The MBUS clocks needs to be always enabled */
__clk_get(mbus);
clk_prepare_enable(mbus);
}
CLK_OF_DECLARE(sun5i_a13_mbus, "allwinner,sun5i-a13-mbus-clk", sun5i_a13_mbus_setup);
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