rockbox/firmware/target/arm/imx31/gigabeat-s/kernel-gigabeat-s.c
Michael Sevakis 0a7d941fb9 i.MX31: Remove long udelay from DVFS interrupt handler
Split the ISR into two parts and alllow quick return from first half.

Introduces a uevent() API to have a callback happen in a specified
number of microseconds. Right now only one event is supported.

Change-Id: Ib1666165be2f6082e5275d64961f083cab104f9f
2013-05-11 21:09:01 -04:00

88 lines
3.2 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2007 by Michael Sevakis
*
* 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "system.h"
#include "avic-imx31.h"
#include "spi-imx31.h"
#include "mc13783.h"
#include "ccm-imx31.h"
#include "sdma-imx31.h"
#include "dvfs_dptc-imx31.h"
#include "kernel.h"
#include "thread.h"
static __attribute__((interrupt("IRQ"))) void EPIT1_HANDLER(void)
{
EPITSR1 = EPITSR_OCIF; /* Clear the pending status */
/* Run through the list of tick tasks */
call_tick_tasks();
}
void INIT_ATTR tick_start(unsigned int interval_in_ms)
{
ccm_module_clock_gating(CG_EPIT1, CGM_ON_RUN_WAIT); /* EPIT1 module
clock ON - before writing
regs! */
EPITCR1 &= ~(EPITCR_OCIEN | EPITCR_EN); /* Disable the counter */
CCM_WIMR0 &= ~CCM_WIMR0_IPI_INT_EPIT1; /* Clear wakeup mask */
/* mcu_main_clk = 528MHz = 27MHz * 2 * ((9 + 7/9) / 1)
* CLKSRC = ipg_clk = 528MHz / 4 / 2 = 66MHz,
* EPIT Output Disconnected,
* Enabled in wait mode
* Prescale 1/2640 for 25KHz
* Reload from modulus register,
* Compare interrupt enabled,
* Count from load value */
EPITCR1 = EPITCR_CLKSRC_IPG_CLK | EPITCR_WAITEN | EPITCR_IOVW |
((2640-1) << EPITCR_PRESCALER_POS) | EPITCR_RLD |
EPITCR_OCIEN | EPITCR_ENMOD;
EPITLR1 = interval_in_ms*25; /* Count down from interval */
EPITCMPR1 = 0; /* Event when counter reaches 0 */
EPITSR1 = EPITSR_OCIF; /* Clear any pending interrupt */
avic_enable_int(INT_EPIT1, INT_TYPE_IRQ, INT_PRIO_DEFAULT,
EPIT1_HANDLER);
EPITCR1 |= EPITCR_EN; /* Enable the counter */
}
void INIT_ATTR kernel_device_init(void)
{
sdma_init();
spi_init();
enable_interrupt(IRQ_FIQ_STATUS);
mc13783_init();
dvfs_dptc_init(); /* Init also sets default points */
#ifndef BOOTLOADER
dvfs_wfi_monitor(true); /* Monitor the WFI signal */
dvfs_start(); /* Should be ok to start even so early */
dptc_start();
#endif
}
void tick_stop(void)
{
avic_disable_int(INT_EPIT1); /* Disable insterrupt */
EPITCR1 &= ~(EPITCR_OCIEN | EPITCR_EN); /* Disable counter */
EPITSR1 = EPITSR_OCIF; /* Clear pending */
ccm_module_clock_gating(CG_EPIT1, CGM_OFF); /* Turn off module clock */
}