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