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ebf9d5261e
We have several boards that use the same ICS307 CLK chip to drive the System clock and DDR clock. Move the code into a common location so we share it. Convert the P2020DS board as the first to use the new common ICS307 code. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Acked-by: Timur Tabi <timur@freescale.com>
88 lines
2.3 KiB
C
88 lines
2.3 KiB
C
/*
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* Copyright 2010 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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#include <common.h>
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#include <asm/io.h>
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#include "ics307_clk.h"
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#ifdef CONFIG_FSL_NGPIXIS
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#include "ngpixis.h"
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#else
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#include "pixis.h"
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#endif
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/* decode S[0-2] to Output Divider (OD) */
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static u8 ics307_s_to_od[] = {
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10, 2, 8, 4, 5, 7, 3, 6
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};
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/*
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* Calculate frequency being generated by ICS307-02 clock chip based upon
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* the control bytes being programmed into it.
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*/
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static unsigned long ics307_clk_freq(u8 cw0, u8 cw1, u8 cw2)
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{
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const unsigned long input_freq = CONFIG_ICS307_REFCLK_HZ;
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unsigned long vdw = ((cw1 << 1) & 0x1FE) + ((cw2 >> 7) & 1);
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unsigned long rdw = cw2 & 0x7F;
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unsigned long od = ics307_s_to_od[cw0 & 0x7];
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unsigned long freq;
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/*
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* CLK1 Freq = Input Frequency * 2 * (VDW + 8) / ((RDW + 2) * OD)
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*
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* cw0: C1 C0 TTL F1 F0 S2 S1 S0
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* cw1: V8 V7 V6 V5 V4 V3 V2 V1
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* cw2: V0 R6 R5 R4 R3 R2 R1 R0
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*
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* R6:R0 = Reference Divider Word (RDW)
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* V8:V0 = VCO Divider Word (VDW)
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* S2:S0 = Output Divider Select (OD)
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* F1:F0 = Function of CLK2 Output
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* TTL = duty cycle
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* C1:C0 = internal load capacitance for cyrstal
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*
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*/
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freq = input_freq * 2 * (vdw + 8) / ((rdw + 2) * od);
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debug("ICS307: CW[0-2]: %02X %02X %02X => %lu Hz\n", cw0, cw1, cw2,
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freq);
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return freq;
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}
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unsigned long get_board_sys_clk(void)
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{
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return ics307_clk_freq(
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in_8(&pixis->sclk[0]),
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in_8(&pixis->sclk[1]),
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in_8(&pixis->sclk[2]));
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}
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unsigned long get_board_ddr_clk(void)
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{
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return ics307_clk_freq(
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in_8(&pixis->dclk[0]),
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in_8(&pixis->dclk[1]),
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in_8(&pixis->dclk[2]));
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}
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