u-boot/arch/arm/cpu/arm926ejs/lpc32xx/clk.c

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/*
* Copyright (C) 2011 by Vladimir Zapolskiy <vz@mleia.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#include <common.h>
#include <div64.h>
#include <asm/arch/cpu.h>
#include <asm/arch/clk.h>
#include <asm/io.h>
static struct clk_pm_regs *clk = (struct clk_pm_regs *)CLK_PM_BASE;
unsigned int get_sys_clk_rate(void)
{
if (readl(&clk->sysclk_ctrl) & CLK_SYSCLK_PLL397)
return RTC_CLK_FREQUENCY * 397;
else
return OSC_CLK_FREQUENCY;
}
unsigned int get_hclk_pll_rate(void)
{
unsigned long long fin, fref, fcco, fout;
u32 val, m_div, n_div, p_div;
/*
* Valid frequency ranges:
* 1 * 10^6 <= Fin <= 20 * 10^6
* 1 * 10^6 <= Fref <= 27 * 10^6
* 156 * 10^6 <= Fcco <= 320 * 10^6
*/
fref = fin = get_sys_clk_rate();
if (fin > 20000000ULL || fin < 1000000ULL)
return 0;
val = readl(&clk->hclkpll_ctrl);
m_div = ((val & CLK_HCLK_PLL_FEEDBACK_DIV_MASK) >> 1) + 1;
n_div = ((val & CLK_HCLK_PLL_PREDIV_MASK) >> 9) + 1;
if (val & CLK_HCLK_PLL_DIRECT)
p_div = 0;
else
p_div = ((val & CLK_HCLK_PLL_POSTDIV_MASK) >> 11) + 1;
p_div = 1 << p_div;
if (val & CLK_HCLK_PLL_BYPASS) {
do_div(fin, p_div);
return fin;
}
do_div(fref, n_div);
if (fref > 27000000ULL || fref < 1000000ULL)
return 0;
fout = fref * m_div;
if (val & CLK_HCLK_PLL_FEEDBACK) {
fcco = fout;
do_div(fout, p_div);
} else
fcco = fout * p_div;
if (fcco > 320000000ULL || fcco < 156000000ULL)
return 0;
return fout;
}
unsigned int get_hclk_clk_div(void)
{
u32 val;
val = readl(&clk->hclkdiv_ctrl) & CLK_HCLK_ARM_PLL_DIV_MASK;
return 1 << val;
}
unsigned int get_hclk_clk_rate(void)
{
return get_hclk_pll_rate() / get_hclk_clk_div();
}
unsigned int get_periph_clk_div(void)
{
u32 val;
val = readl(&clk->hclkdiv_ctrl) & CLK_HCLK_PERIPH_DIV_MASK;
return (val >> 2) + 1;
}
unsigned int get_periph_clk_rate(void)
{
if (!(readl(&clk->pwr_ctrl) & CLK_PWR_NORMAL_RUN))
return get_sys_clk_rate();
return get_hclk_pll_rate() / get_periph_clk_div();
}
int get_serial_clock(void)
{
return get_periph_clk_rate();
}