/*
* 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 <linux/of.h>
#include <linux/of_address.h>
#include <linux/reset-controller.h>
#include "clk-factors.h"
static DEFINE_SPINLOCK(clk_lock);
/* Maximum number of parents our clocks have */
#define SUNXI_MAX_PARENTS 5
/**
* sun4i_get_pll1_factors() - calculates n, k, m, p factors for PLL1
* PLL1 rate is calculated as follows
* rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
* parent_rate is always 24Mhz
*/
static void sun4i_get_pll1_factors(u32 *freq, u32 parent_rate,
u8 *n, u8 *k, u8 *m, u8 *p)
{
u8 div;
/* Normalize value to a 6M multiple */
div = *freq / 6000000;
*freq = 6000000 * div;
/* we were called to round the frequency, we can now return */
if (n == NULL)
return;
/* m is always zero for pll1 */
*m = 0;
/* k is 1 only on these cases */
if (*freq >= 768000000 || *freq == 42000000 || *freq == 54000000)
*k = 1;
else
*k = 0;
/* p will be 3 for divs under 10 */
if (div < 10)
*p = 3;
/* p will be 2 for divs between 10 - 20 and odd divs under 32 */
else if (div < 20 || (div < 32 && (div & 1)))
*p = 2;
/* p will be 1 for even divs under 32, divs under 40 and odd pairs
* of divs between 40-62 */
else if (div < 40 || (div < 64 && (div & 2)))
*p = 1;
/* any other entries have p = 0 */
else
*p = 0;
/* calculate a suitable n based on k and p */
div <<= *p;
div /= (*k + 1);
*n = div / 4;
}
/**
* sun6i_a31_get_pll1_factors() - calculates n, k and m factors for PLL1
* PLL1 rate is calculated as follows
* rate = parent_rate * (n + 1) * (k + 1) / (m + 1);
* parent_rate should always be 24MHz
*/
static void sun6i_a31_get_pll1_factors(u32 *freq, u32 parent_rate,
u8 *n, u8 *k, u8 *m, u8 *p)
{
/*
* We can operate only on MHz, this will make our life easier
* later.
*/
u32 freq_mhz = *freq / 1000000;
u32 parent_freq_mhz = parent_rate / 1000000;
/*
* Round down the frequency to the closest multiple of either
* 6 or 16
*/
u32 round_freq_6 = round_down(freq_mhz, 6);
u32 round_freq_16 = round_down(freq_mhz, 16);
if (round_freq_6 > round_freq_16)
freq_mhz = round_freq_6;
else
freq_mhz = round_freq_16;
*freq