barebox/arch/arm/mach-pxa/common.c
Sascha Hauer 83b0a5ae05 restart: replace reset_cpu with registered restart handlers
This replaces the reset_cpu() function which every SoC or board must
provide with registered handlers. This makes it possible to have multiple
reset functions for boards which have multiple ways to reset the machine.
Also boards which have no way at all to reset the machine no longer
have to provide a dummy reset_cpu() function.

The problem this solves is that some machines have external PMICs or
similar to reset the system which have to be preferred over the
internal SoC reset, because the PMIC can reset not only the SoC but also
the external devices.

To pick the right way to reset a machine each handler has a priority. The
default priority is 100 and all currently existing restart handlers are
registered with this priority. of_get_restart_priority() allows to retrieve
the priority from the device tree which makes it possible for boards to
give certain restart handlers a higher priority in order to use this one
instead of the default one.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2015-08-27 21:37:03 +02:00

54 lines
1.4 KiB
C

/*
* (C) Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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 program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <common.h>
#include <init.h>
#include <restart.h>
#include <mach/pxa-regs.h>
#include <asm/io.h>
#define OSMR3 0x40A0000C
#define OSCR 0x40A00010
#define OSSR 0x40A00014
#define OWER 0x40A00018
#define OWER_WME (1 << 0) /* Watch-dog Match Enable */
#define OSSR_M3 (1 << 3) /* Match status channel 3 */
extern void pxa_clear_reset_source(void);
static void __noreturn pxa_restart_soc(struct restart_handler *rst)
{
/* Clear last reset source */
pxa_clear_reset_source();
/* Initialize the watchdog and let it fire */
writel(OWER_WME, OWER);
writel(OSSR_M3, OSSR);
writel(readl(OSCR) + 368640, OSMR3); /* ... in 100 ms */
hang();
}
static int restart_register_feature(void)
{
restart_handler_register_fn(pxa_restart_soc);
return 0;
}
coredevice_initcall(restart_register_feature);