freebsd-dev/sys/arm/freescale/imx/imx_machdep.c
Ian Lepore 83988d944b Handle imx6 erratum ERR004346... to reboot, clear the SRS bit twice within
the same cycle of the 32khz clock.

I've never actually noticed this error happening, but it's an easy fix.
2017-01-24 02:09:30 +00:00

113 lines
3.7 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("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/reboot.h>
#include <sys/devmap.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/armreg.h>
#include <machine/bus.h>
#include <machine/machdep.h>
#include <arm/freescale/imx/imx_machdep.h>
#include <arm/freescale/imx/imx_wdogreg.h>
SYSCTL_NODE(_hw, OID_AUTO, imx, CTLFLAG_RW, NULL, "i.MX container");
static int last_reset_status;
SYSCTL_UINT(_hw_imx, OID_AUTO, last_reset_status, CTLFLAG_RD,
&last_reset_status, 0, "Last reset status register");
SYSCTL_STRING(_hw_imx, OID_AUTO, last_reset_reason, CTLFLAG_RD,
"unknown", 0, "Last reset reason");
/*
* 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.
*
* Imx6 erratum ERR004346 says the SRS bit has to be cleared twice
* within the same cycle of the 32khz clock to reliably trigger the
* reset. Writing it 3 times in a row ensures at least 2 of the writes
* happen in the same 32k clock cycle.
*/
if ((pcr = devmap_ptov(wdcr_physaddr, sizeof(*pcr))) == NULL) {
printf("cpu_reset() can't find its control register... locking up now.");
} else {
*pcr &= ~WDOG_CR_SRS;
*pcr &= ~WDOG_CR_SRS;
*pcr &= ~WDOG_CR_SRS;
}
for (;;)
continue;
}
void
imx_wdog_init_last_reset(vm_offset_t wdsr_phys)
{
volatile uint16_t * psr;
if ((psr = devmap_ptov(wdsr_phys, sizeof(*psr))) == NULL)
return;
last_reset_status = *psr;
if (last_reset_status & WDOG_RSR_SFTW) {
sysctl___hw_imx_last_reset_reason.oid_arg1 = "SoftwareReset";
} else if (last_reset_status & WDOG_RSR_TOUT) {
sysctl___hw_imx_last_reset_reason.oid_arg1 = "WatchdogTimeout";
} else if (last_reset_status & WDOG_RSR_POR) {
sysctl___hw_imx_last_reset_reason.oid_arg1 = "PowerOnReset";
}
}
u_int
imx_soc_family(void)
{
return (imx_soc_type() >> IMXSOC_FAMSHIFT);
}