xgene-reboot.c
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/*
* AppliedMicro X-Gene SoC Reboot Driver
*
* Copyright (c) 2013, Applied Micro Circuits Corporation
* Author: Feng Kan <fkan@apm.com>
* Author: Loc Ho <lho@apm.com>
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
* This driver provides system reboot functionality for APM X-Gene SoC.
* For system shutdown, this is board specify. If a board designer
* implements GPIO shutdown, use the gpio-poweroff.c driver.
*/
#include <linux/io.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <asm/system_misc.h>
struct xgene_reboot_context {
struct platform_device *pdev;
void *csr;
u32 mask;
};
static struct xgene_reboot_context *xgene_restart_ctx;
static void xgene_restart(char str, const char *cmd)
{
struct xgene_reboot_context *ctx = xgene_restart_ctx;
unsigned long timeout;
/* Issue the reboot */
if (ctx)
writel(ctx->mask, ctx->csr);
timeout = jiffies + HZ;
while (time_before(jiffies, timeout))
cpu_relax();
dev_emerg(&ctx->pdev->dev, "Unable to restart system\n");
}
static int xgene_reboot_probe(struct platform_device *pdev)
{
struct xgene_reboot_context *ctx;
ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
if (!ctx) {
dev_err(&pdev->dev, "out of memory for context\n");
return -ENODEV;
}
ctx->csr = of_iomap(pdev->dev.of_node, 0);
if (!ctx->csr) {
devm_kfree(&pdev->dev, ctx);
dev_err(&pdev->dev, "can not map resource\n");
return -ENODEV;
}
if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask))
ctx->mask = 0xFFFFFFFF;
ctx->pdev = pdev;
arm_pm_restart = xgene_restart;
xgene_restart_ctx = ctx;
return 0;
}
static struct of_device_id xgene_reboot_of_match[] = {
{ .compatible = "apm,xgene-reboot" },
{}
};
static struct platform_driver xgene_reboot_driver = {
.probe = xgene_reboot_probe,
.driver = {
.name = "xgene-reboot",
.of_match_table = xgene_reboot_of_match,
},
};
static int __init xgene_reboot_init(void)
{
return platform_driver_register(&xgene_reboot_driver);
}
device_initcall(xgene_reboot_init);