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/*
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powerpc/mpc85xx: Set SYSCLK to the required frequency
For ICS307-02, there is one general expression to generate SYSCLK:
CLK1Frequency = InputFrequency * 2 * (VDW + 8) / ((RDW + 2) * OD)
If we want the required frequency for SYSCLK, we must find one solution
to generate this frequency, this solution includes VDW, RDW and OD.
For OD, there are only eight option value: 10, 2, 8, 4, 5, 7, 3, 6.
For RDW, the range is 1 to 127.
For VDW, the range is 4 to 511.
First, we use one OD, RDW and required SYSCLK to calculate the VDW,
if VDW is in it's range, we will calculate the CLK1Frequency with
the OD, RDW and VDW calculated, and we will check this percent
(CLK1Frequency / required SYSCLK), and the precision is 1/1000.
if the percent is less than 1/1000, we think the CLK1Frequency is we want.
Otherwise, We will continue to calculate it with the next OD and RDW.
Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
13 years ago
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* Copyright 2010-2011 Freescale Semiconductor, Inc.
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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#ifndef __ICS_CLK_H_
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#define __ICS_CLK_H_ 1
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#ifndef __ASSEMBLY__
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powerpc/mpc85xx: Set SYSCLK to the required frequency
For ICS307-02, there is one general expression to generate SYSCLK:
CLK1Frequency = InputFrequency * 2 * (VDW + 8) / ((RDW + 2) * OD)
If we want the required frequency for SYSCLK, we must find one solution
to generate this frequency, this solution includes VDW, RDW and OD.
For OD, there are only eight option value: 10, 2, 8, 4, 5, 7, 3, 6.
For RDW, the range is 1 to 127.
For VDW, the range is 4 to 511.
First, we use one OD, RDW and required SYSCLK to calculate the VDW,
if VDW is in it's range, we will calculate the CLK1Frequency with
the OD, RDW and VDW calculated, and we will check this percent
(CLK1Frequency / required SYSCLK), and the precision is 1/1000.
if the percent is less than 1/1000, we think the CLK1Frequency is we want.
Otherwise, We will continue to calculate it with the next OD and RDW.
Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
13 years ago
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extern unsigned long get_board_sys_clk(void);
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extern unsigned long get_board_ddr_clk(void);
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powerpc/mpc85xx: Set SYSCLK to the required frequency
For ICS307-02, there is one general expression to generate SYSCLK:
CLK1Frequency = InputFrequency * 2 * (VDW + 8) / ((RDW + 2) * OD)
If we want the required frequency for SYSCLK, we must find one solution
to generate this frequency, this solution includes VDW, RDW and OD.
For OD, there are only eight option value: 10, 2, 8, 4, 5, 7, 3, 6.
For RDW, the range is 1 to 127.
For VDW, the range is 4 to 511.
First, we use one OD, RDW and required SYSCLK to calculate the VDW,
if VDW is in it's range, we will calculate the CLK1Frequency with
the OD, RDW and VDW calculated, and we will check this percent
(CLK1Frequency / required SYSCLK), and the precision is 1/1000.
if the percent is less than 1/1000, we think the CLK1Frequency is we want.
Otherwise, We will continue to calculate it with the next OD and RDW.
Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
13 years ago
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extern unsigned long ics307_sysclk_calculator(unsigned long out_freq);
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#endif
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#endif /* __ICS_CLK_H_ */
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