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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * AppliedMicro X-Gene SoC Reboot Driver4 *5 * Copyright (c) 2013, Applied Micro Circuits Corporation6 * Author: Feng Kan <fkan@apm.com>7 * Author: Loc Ho <lho@apm.com>8 *9 * This driver provides system reboot functionality for APM X-Gene SoC.10 * For system shutdown, this is board specify. If a board designer11 * implements GPIO shutdown, use the gpio-poweroff.c driver.12 */13#include <linux/delay.h>14#include <linux/io.h>15#include <linux/notifier.h>16#include <linux/of.h>17#include <linux/of_address.h>18#include <linux/platform_device.h>19#include <linux/reboot.h>20#include <linux/stat.h>21#include <linux/slab.h>22 23struct xgene_reboot_context {24 struct device *dev;25 void __iomem *csr;26 u32 mask;27};28 29static int xgene_restart_handler(struct sys_off_data *data)30{31 struct xgene_reboot_context *ctx = data->cb_data;32 33 /* Issue the reboot */34 writel(ctx->mask, ctx->csr);35 36 mdelay(1000);37 38 dev_emerg(ctx->dev, "Unable to restart system\n");39 40 return NOTIFY_DONE;41}42 43static int xgene_reboot_probe(struct platform_device *pdev)44{45 struct xgene_reboot_context *ctx;46 struct device *dev = &pdev->dev;47 int err;48 49 ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);50 if (!ctx)51 return -ENOMEM;52 53 ctx->csr = devm_platform_ioremap_resource(pdev, 0);54 if (IS_ERR(ctx->csr)) {55 dev_err(dev, "can not map resource\n");56 return PTR_ERR(ctx->csr);57 }58 59 if (of_property_read_u32(dev->of_node, "mask", &ctx->mask))60 ctx->mask = 0xFFFFFFFF;61 62 ctx->dev = dev;63 err = devm_register_sys_off_handler(dev, SYS_OFF_MODE_RESTART, 128,64 xgene_restart_handler, ctx);65 if (err)66 dev_err(dev, "cannot register restart handler (err=%d)\n", err);67 68 return err;69}70 71static const struct of_device_id xgene_reboot_of_match[] = {72 { .compatible = "apm,xgene-reboot" },73 {}74};75 76static struct platform_driver xgene_reboot_driver = {77 .probe = xgene_reboot_probe,78 .driver = {79 .name = "xgene-reboot",80 .of_match_table = xgene_reboot_of_match,81 },82};83builtin_platform_driver(xgene_reboot_driver);84