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/*
* Copyright 2010 Freescale Semiconductor, Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <asm/io.h>
#include "ics307_clk.h"
#ifdef CONFIG_FSL_NGPIXIS
#include "ngpixis.h"
#else
#include "pixis.h"
#endif
/* decode S[0-2] to Output Divider (OD) */
static u8 ics307_s_to_od[] = {
10, 2, 8, 4, 5, 7, 3, 6
};
/*
* Calculate frequency being generated by ICS307-02 clock chip based upon
* the control bytes being programmed into it.
*/
static unsigned long ics307_clk_freq(u8 cw0, u8 cw1, u8 cw2)
{
const unsigned long input_freq = CONFIG_ICS307_REFCLK_HZ;
unsigned long vdw = ((cw1 << 1) & 0x1FE) + ((cw2 >> 7) & 1);
unsigned long rdw = cw2 & 0x7F;
unsigned long od = ics307_s_to_od[cw0 & 0x7];
unsigned long freq;
/*
* CLK1 Freq = Input Frequency * 2 * (VDW + 8) / ((RDW + 2) * OD)
*
* cw0: C1 C0 TTL F1 F0 S2 S1 S0
* cw1: V8 V7 V6 V5 V4 V3 V2 V1
* cw2: V0 R6 R5 R4 R3 R2 R1 R0
*
* R6:R0 = Reference Divider Word (RDW)
* V8:V0 = VCO Divider Word (VDW)
* S2:S0 = Output Divider Select (OD)
* F1:F0 = Function of CLK2 Output
* TTL = duty cycle
* C1:C0 = internal load capacitance for cyrstal
*
*/
freq = input_freq * 2 * (vdw + 8) / ((rdw + 2) * od);
debug("ICS307: CW[0-2]: %02X %02X %02X => %lu Hz\n", cw0, cw1, cw2,
freq);
return freq;
}
unsigned long get_board_sys_clk(void)
{
return ics307_clk_freq(
in_8(&pixis->sclk[0]),
in_8(&pixis->sclk[1]),
in_8(&pixis->sclk[2]));
}
unsigned long get_board_ddr_clk(void)
{
return ics307_clk_freq(
in_8(&pixis->dclk[0]),
in_8(&pixis->dclk[1]),
in_8(&pixis->dclk[2]));
}
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