linux/arch/arm/mach-mvebu/cpu-reset.c

103 lines
2.1 KiB
C

/*
* Copyright (C) 2014 Marvell
*
* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#define pr_fmt(fmt) "mvebu-cpureset: " fmt
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/of_address.h>
#include <linux/io.h>
#include <linux/resource.h>
static void __iomem *cpu_reset_base;
static size_t cpu_reset_size;
#define CPU_RESET_OFFSET(cpu) (cpu * 0x8)
#define CPU_RESET_ASSERT BIT(0)
int mvebu_cpu_reset_deassert(int cpu)
{
u32 reg;
if (!cpu_reset_base)
return -ENODEV;
if (CPU_RESET_OFFSET(cpu) >= cpu_reset_size)
return -EINVAL;
reg = readl(cpu_reset_base + CPU_RESET_OFFSET(cpu));
reg &= ~CPU_RESET_ASSERT;
writel(reg, cpu_reset_base + CPU_RESET_OFFSET(cpu));
return 0;
}
static int mvebu_cpu_reset_map(struct device_node *np, int res_idx)
{
struct resource res;
if (of_address_to_resource(np, res_idx, &res)) {
pr_err("unable to get resource\n");
return -ENOENT;
}
if (!request_mem_region(res.start, resource_size(&res),
np->full_name)) {
pr_err("unable to request region\n");
return -EBUSY;
}
cpu_reset_base = ioremap(res.start, resource_size(&res));
if (!cpu_reset_base) {
pr_err("unable to map registers\n");
release_mem_region(res.start, resource_size(&res));
return -ENOMEM;
}
cpu_reset_size = resource_size(&res);
return 0;
}
static int __init mvebu_cpu_reset_init(void)
{
struct device_node *np;
int res_idx;
int ret;
np = of_find_compatible_node(NULL, NULL,
"marvell,armada-370-cpu-reset");
if (np) {
res_idx = 0;
} else {
/*
* This code is kept for backward compatibility with
* old Device Trees.
*/
np = of_find_compatible_node(NULL, NULL,
"marvell,armada-370-xp-pmsu");
if (np) {
pr_warn(FW_WARN "deprecated pmsu binding\n");
res_idx = 1;
}
}
/* No reset node found */
if (!np)
return -ENODEV;
ret = mvebu_cpu_reset_map(np, res_idx);
of_node_put(np);
return ret;
}
early_initcall(mvebu_cpu_reset_init);