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>

2 files changed, 1 insertions, 26 deletions

diff --git a/arch/arm/mach-digic/Makefile b/arch/arm/mach-digic/Makefile
index 820eb10ac2..16a218658a 100644
--- a/arch/arm/mach-digic/Makefile
+++ b/arch/arm/mach-digic/Makefile
@@ -1 +1 @@
-obj-y += core.o
+obj- := __dummy__.o
diff --git a/arch/arm/mach-digic/core.c b/arch/arm/mach-digic/core.c
deleted file mode 100644
index b1caec0bc8..0000000000
--- a/arch/arm/mach-digic/core.c
+++ /dev/null
@@ -1,25 +0,0 @@
-/*
- * Copyright (C) 2013 Antony Pavlov <antonynpavlov@gmail.com>
- *
- * This file is part of barebox.
- * 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 version 2
- * as published by the Free Software Foundation.
- *
- * 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>
-
-void __noreturn reset_cpu(unsigned long ignored)
-{
-	pr_err("%s: unimplemented\n", __func__);
-	hang();
-}
-EXPORT_SYMBOL(reset_cpu);