a85780bacc
This patch implements HAVE_ADJUSTABLE_CPU_FREQ, it modifies the following parameters when CPU is unboosted: - s5l8702 voltage is decreased: 1.200V -> 1.050V - CPU frequency is divided by 4: 216MHz -> 54MHz - AHB frequency is divided by 2: 108MHz -> 54MHz Change-Id: I2285b83efb7e1567864ac288f2d4ba55f058f7c5
57 lines
2 KiB
C
57 lines
2 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id: kernel-s5l8700.c 28795 2010-12-11 17:52:52Z Buschel $
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*
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* Copyright © 2009 Bertrik Sikken
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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
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#include "config.h"
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#include "system.h"
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#include "kernel.h"
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/* S5L8702 driver for the kernel timer
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Timer B is configured as a 10 kHz timer
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*/
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void INT_TIMERB(void)
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{
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/* clear interrupt */
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TBCON = TBCON;
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call_tick_tasks(); /* Run through the list of tick tasks */
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}
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void tick_start(unsigned int interval_in_ms)
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{
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int cycles = 10 * interval_in_ms;
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/* configure timer for 10 kHz (external source) */
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TBCMD = (1 << 1); /* TB_CLR */
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TBPRE = 75 - 1; /* prescaler */ /* 12 MHz / 16 / 75 = 10 KHz */
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TBCON = (0 << 13) | /* TB_INT1_EN */
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(1 << 12) | /* TB_INT0_EN */
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(0 << 11) | /* TB_START */
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(2 << 8) | /* TB_CS = PCLK / 16 */
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(1 << 6) | /* UNKNOWN bit */ /* external 12 MHz clock (?) */
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(0 << 4); /* TB_MODE_SEL = interval mode */
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TBDATA0 = cycles; /* set interval period */
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TBCMD = (1 << 0); /* TB_EN */
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/* enable timer interrupt */
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VIC0INTENABLE = 1 << IRQ_TIMER;
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}
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