freebsd-dev/sys/arm/freescale/imx/imx_machdep.c
Ian Lepore e0848bbb0c Update the imx5/imx6 cpu_reset() implementation based on a new understanding
of the SRS (software reset) bit in the watchdog control register.  Despite
what the manual seems to imply, this bit DOES trigger an immediate reset, as
opposed to simply flagging the type of reset as software-triggered.
2015-11-21 23:30:47 +00:00

95 lines
2.8 KiB
C

/*-
* Copyright (c) 2013 Ian Lepore <ian@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "opt_platform.h"
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#define _ARM32_BUS_DMA_PRIVATE
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/reboot.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/armreg.h>
#include <machine/bus.h>
#include <machine/devmap.h>
#include <machine/machdep.h>
#include <arm/freescale/imx/imx_machdep.h>
#include <arm/freescale/imx/imx_wdogreg.h>
struct arm32_dma_range *
bus_dma_get_range(void)
{
return (NULL);
}
int
bus_dma_get_range_nb(void)
{
return (0);
}
/*
* This code which manipulates the watchdog hardware is here to implement
* cpu_reset() because the watchdog is the only way for software to reset the
* chip. Why here and not in imx_wdog.c? Because there's no requirement that
* the watchdog driver be compiled in, but it's nice to be able to reboot even
* if it's not.
*/
void
imx_wdog_cpu_reset(vm_offset_t wdcr_physaddr)
{
volatile uint16_t * pcr;
/*
* Trigger an immediate reset by clearing the SRS bit in the watchdog
* control register. The reset happens on the next cycle of the wdog
* 32KHz clock, so hang out in a spin loop until the reset takes effect.
*/
if ((pcr = arm_devmap_ptov(wdcr_physaddr, sizeof(*pcr))) == NULL) {
printf("cpu_reset() can't find its control register... locking up now.");
} else {
*pcr &= ~WDOG_CR_SRS;
}
for (;;)
continue;
}
u_int
imx_soc_family(void)
{
return (imx_soc_type() >> IMXSOC_FAMSHIFT);
}