LXR linux/drivers/power/reset/xgene-reboot.c

   1/*
   2 * AppliedMicro X-Gene SoC Reboot Driver
   3 *
   4 * Copyright (c) 2013, Applied Micro Circuits Corporation
   5 * Author: Feng Kan <fkan@apm.com>
   6 * Author: Loc Ho <lho@apm.com>
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License as
  10 * published by the Free Software Foundation; either version 2 of
  11 * the License, or (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the Free Software
  20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21 * MA 02111-1307 USA
  22 *
  23 * This driver provides system reboot functionality for APM X-Gene SoC.
  24 * For system shutdown, this is board specify. If a board designer
  25 * implements GPIO shutdown, use the gpio-poweroff.c driver.
  26 */
  27#include <linux/delay.h>
  28#include <linux/io.h>
  29#include <linux/notifier.h>
  30#include <linux/of_device.h>
  31#include <linux/of_address.h>
  32#include <linux/platform_device.h>
  33#include <linux/reboot.h>
  34#include <linux/stat.h>
  35#include <linux/slab.h>
  36
  37struct xgene_reboot_context {
  38        struct device *dev;
  39        void *csr;
  40        u32 mask;
  41        struct notifier_block restart_handler;
  42};
  43
  44static int xgene_restart_handler(struct notifier_block *this,
  45                                 unsigned long mode, void *cmd)
  46{
  47        struct xgene_reboot_context *ctx =
  48                container_of(this, struct xgene_reboot_context,
  49                             restart_handler);
  50
  51        /* Issue the reboot */
  52        writel(ctx->mask, ctx->csr);
  53
  54        mdelay(1000);
  55
  56        dev_emerg(ctx->dev, "Unable to restart system\n");
  57
  58        return NOTIFY_DONE;
  59}
  60
  61static int xgene_reboot_probe(struct platform_device *pdev)
  62{
  63        struct xgene_reboot_context *ctx;
  64        struct device *dev = &pdev->dev;
  65        int err;
  66
  67        ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
  68        if (!ctx)
  69                return -ENOMEM;
  70
  71        ctx->csr = of_iomap(dev->of_node, 0);
  72        if (!ctx->csr) {
  73                dev_err(dev, "can not map resource\n");
  74                return -ENODEV;
  75        }
  76
  77        if (of_property_read_u32(dev->of_node, "mask", &ctx->mask))
  78                ctx->mask = 0xFFFFFFFF;
  79
  80        ctx->dev = dev;
  81        ctx->restart_handler.notifier_call = xgene_restart_handler;
  82        ctx->restart_handler.priority = 128;
  83        err = register_restart_handler(&ctx->restart_handler);
  84        if (err) {
  85                iounmap(ctx->csr);
  86                dev_err(dev, "cannot register restart handler (err=%d)\n", err);
  87        }
  88
  89        return err;
  90}
  91
  92static const struct of_device_id xgene_reboot_of_match[] = {
  93        { .compatible = "apm,xgene-reboot" },
  94        {}
  95};
  96
  97static struct platform_driver xgene_reboot_driver = {
  98        .probe = xgene_reboot_probe,
  99        .driver = {
 100                .name = "xgene-reboot",
 101                .of_match_table = xgene_reboot_of_match,
 102        },
 103};
 104
 105static int __init xgene_reboot_init(void)
 106{
 107        return platform_driver_register(&xgene_reboot_driver);
 108}
 109device_initcall(xgene_reboot_init);
 110