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