u-boot/arch/blackfin/lib/clocks.c

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/*
* clocks.c - figure out sclk/cclk/vco and such
*
* Copyright (c) 2005-2008 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
#include <common.h>
#include <asm/clock.h>
/* Get the voltage input multiplier */
u_long get_vco(void)
{
static u_long cached_vco_pll_ctl, cached_vco;
u_long msel, pll_ctl;
pll_ctl = bfin_read_PLL_CTL();
if (pll_ctl == cached_vco_pll_ctl)
return cached_vco;
else
cached_vco_pll_ctl = pll_ctl;
msel = (pll_ctl & MSEL) >> MSEL_P;
if (0 == msel)
msel = (MSEL >> MSEL_P) + 1;
cached_vco = CONFIG_CLKIN_HZ;
cached_vco >>= (pll_ctl & DF);
cached_vco *= msel;
return cached_vco;
}
/* Get the Core clock */
u_long get_cclk(void)
{
static u_long cached_cclk_pll_div, cached_cclk;
u_long div, csel;
#ifndef CGU_DIV
u_long ssel;
#endif
if (pll_is_bypassed())
return CONFIG_CLKIN_HZ;
div = bfin_read_PLL_DIV();
if (div == cached_cclk_pll_div)
return cached_cclk;
else
cached_cclk_pll_div = div;
csel = (div & CSEL) >> CSEL_P;
#ifndef CGU_DIV
ssel = (div & SSEL) >> SSEL_P;
if (ssel && ssel < (1 << csel)) /* SCLK > CCLK */
cached_cclk = get_vco() / ssel;
else
cached_cclk = get_vco() >> csel;
#else
cached_cclk = get_vco() / csel;
#endif
return cached_cclk;
}
/* Get the System clock */
#ifdef CGU_DIV
static u_long cached_sclk_pll_div, cached_sclk;
static u_long cached_sclk0, cached_sclk1, cached_dclk;
static u_long _get_sclk(u_long *cache)
{
u_long div, ssel;
if (pll_is_bypassed())
return CONFIG_CLKIN_HZ;
div = bfin_read_PLL_DIV();
if (div == cached_sclk_pll_div)
return *cache;
else
cached_sclk_pll_div = div;
ssel = (div & SYSSEL) >> SYSSEL_P;
cached_sclk = get_vco() / ssel;
ssel = (div & S0SEL) >> S0SEL_P;
cached_sclk0 = cached_sclk / ssel;
ssel = (div & S1SEL) >> S1SEL_P;
cached_sclk1 = cached_sclk / ssel;
ssel = (div & DSEL) >> DSEL_P;
cached_dclk = get_vco() / ssel;
return *cache;
}
u_long get_sclk(void)
{
return _get_sclk(&cached_sclk);
}
u_long get_sclk0(void)
{
return _get_sclk(&cached_sclk0);
}
u_long get_sclk1(void)
{
return _get_sclk(&cached_sclk1);
}
u_long get_dclk(void)
{
return _get_sclk(&cached_dclk);
}
#else
u_long get_sclk(void)
{
static u_long cached_sclk_pll_div, cached_sclk;
u_long div, ssel;
if (pll_is_bypassed())
return CONFIG_CLKIN_HZ;
div = bfin_read_PLL_DIV();
if (div == cached_sclk_pll_div)
return cached_sclk;
else
cached_sclk_pll_div = div;
ssel = (div & SSEL) >> SSEL_P;
cached_sclk = get_vco() / ssel;
return cached_sclk;
}
#endif