79 lines
1.6 KiB
C
79 lines
1.6 KiB
C
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/*
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* Copyright (C) 2012 Analog Devices Inc.
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* Licensed under the GPL-2 or later.
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*/
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#ifndef __CLOCK_H__
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#define __CLOCK_H__
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#include <asm/blackfin.h>
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#ifdef PLL_CTL
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#include <asm/mach-common/bits/pll.h>
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# define pll_is_bypassed() (bfin_read_PLL_CTL() & BYPASS)
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#else
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#include <asm/mach-common/bits/cgu.h>
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# define pll_is_bypassed() (bfin_read_CGU_STAT() & PLLBP)
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# define bfin_read_PLL_CTL() bfin_read_CGU_CTL()
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# define bfin_read_PLL_DIV() bfin_read_CGU_DIV()
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# define SSEL SYSSEL
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# define SSEL_P SYSSEL_P
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#endif
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__attribute__((always_inline))
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static inline uint32_t early_division(uint32_t dividend, uint32_t divisor)
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{
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uint32_t quotient;
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uint32_t i, j;
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for (quotient = 1, i = 1; dividend > divisor; ++i) {
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j = divisor << i;
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if (j > dividend || (j & 0x80000000)) {
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--i;
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quotient += (1 << i);
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dividend -= (divisor << i);
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i = 0;
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}
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}
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return quotient;
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}
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__attribute__((always_inline))
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static inline uint32_t early_get_uart_clk(void)
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{
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uint32_t msel, pll_ctl, vco;
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uint32_t div, ssel, sclk, uclk;
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pll_ctl = bfin_read_PLL_CTL();
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msel = (pll_ctl & MSEL) >> MSEL_P;
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if (msel == 0)
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msel = (MSEL >> MSEL_P) + 1;
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vco = (CONFIG_CLKIN_HZ >> (pll_ctl & DF)) * msel;
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sclk = vco;
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if (!pll_is_bypassed()) {
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div = bfin_read_PLL_DIV();
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ssel = (div & SSEL) >> SSEL_P;
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#if CONFIG_BFIN_BOOT_MODE == BFIN_BOOT_BYPASS
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sclk = vco/ssel;
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#else
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sclk = early_division(vco, ssel);
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#endif
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}
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uclk = sclk;
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#ifdef CGU_DIV
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ssel = (div & S0SEL) >> S0SEL_P;
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uclk = early_division(sclk, ssel);
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#endif
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return uclk;
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}
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#ifdef CGU_DIV
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# define get_uart_clk get_sclk0
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#else
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# define get_uart_clk get_sclk
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#endif
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#endif
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