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/*
* Copyright 2008-2012 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* Version 2 as published by the Free Software Foundation.
*/
#include <common.h>
#include <asm/fsl_law.h>
#include <asm-generic/div64.h>
#include <mach/clock.h>
#include "ddr.h"
#define ULL_2E12 2000000000000ULL
#define UL_5POW12 244140625UL
#define UL_2POW13 (1UL << 13)
#define ULL_8FS 0xFFFFFFFFULL
/*
* Round up mclk_ps to nearest 1 ps in memory controller code
* if the error is 0.5ps or more.
*
* If an imprecise data rate is too high due to rounding error
* propagation, compute a suitably rounded mclk_ps to compute
* a working memory controller configuration.
*/
uint32_t get_memory_clk_period_ps(void)
{
uint32_t result, data_rate = fsl_get_ddr_freq(0);
/* Round to nearest 10ps, being careful about 64-bit multiply/divide */
uint64_t rem, mclk_ps = ULL_2E12;
/* Now perform the big divide, the result fits in 32-bits */
rem = do_div(mclk_ps, data_rate);
if (rem >= (data_rate >> 1))
result = mclk_ps + 1;
else
result = mclk_ps;
return result;
}
/* Convert picoseconds into DRAM clock cycles (rounding up if needed). */
uint32_t picos_to_mclk(uint32_t picos)
{
uint64_t clks, clks_rem;
uint32_t data_rate = fsl_get_ddr_freq(0);
if (!picos)
return 0;
/* First multiply the time by the data rate (32x32 => 64) */
clks = picos * (uint64_t)data_rate;
/*
* Now divide by 5^12 and track the 32-bit remainder, then divide
* by 2*(2^12) using shifts (and updating the remainder).
*/
clks_rem = do_div(clks, UL_5POW12);
clks_rem += (clks & (UL_2POW13 - 1)) * UL_5POW12;
clks >>= 13;
/* If we had a remainder greater than the 1ps error, then round up */
if (clks_rem > data_rate)
clks++;
if (clks > ULL_8FS)
clks = ULL_8FS;
return (uint32_t)clks;
}
uint32_t mclk_to_picos(unsigned int mclk)
{
return get_memory_clk_period_ps() * mclk;
}
int fsl_ddr_set_lawbar(
const struct common_timing_params_s *params,
uint32_t law_memctl)
{
uint64_t base = params->base_address;
uint64_t size = params->total_mem;
if (!params->ndimms_present)
goto out;
if (base >= MAX_MEM_MAPPED)
goto error;
if ((base + size) >= MAX_MEM_MAPPED)
size = MAX_MEM_MAPPED - base;
if (fsl_set_ddr_laws(base, size, law_memctl) < 0)
goto error;
out:
return 0;
error:
return 1;
}
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