1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * AppliedMicro X-Gene SoC Reboot Driver |
4 | * |
5 | * Copyright (c) 2013, Applied Micro Circuits Corporation |
6 | * 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 designer |
11 | * 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 | |
23 | struct xgene_reboot_context { |
24 | struct device *dev; |
25 | void __iomem *csr; |
26 | u32 mask; |
27 | }; |
28 | |
29 | static 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(val: ctx->mask, addr: ctx->csr); |
35 | |
36 | mdelay(1000); |
37 | |
38 | dev_emerg(ctx->dev, "Unable to restart system\n" ); |
39 | |
40 | return NOTIFY_DONE; |
41 | } |
42 | |
43 | static 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, size: sizeof(*ctx), GFP_KERNEL); |
50 | if (!ctx) |
51 | return -ENOMEM; |
52 | |
53 | ctx->csr = devm_platform_ioremap_resource(pdev, index: 0); |
54 | if (IS_ERR(ptr: ctx->csr)) { |
55 | dev_err(dev, "can not map resource\n" ); |
56 | return PTR_ERR(ptr: ctx->csr); |
57 | } |
58 | |
59 | if (of_property_read_u32(np: dev->of_node, propname: "mask" , out_value: &ctx->mask)) |
60 | ctx->mask = 0xFFFFFFFF; |
61 | |
62 | ctx->dev = dev; |
63 | err = devm_register_sys_off_handler(dev, mode: SYS_OFF_MODE_RESTART, priority: 128, |
64 | callback: xgene_restart_handler, cb_data: ctx); |
65 | if (err) |
66 | dev_err(dev, "cannot register restart handler (err=%d)\n" , err); |
67 | |
68 | return err; |
69 | } |
70 | |
71 | static const struct of_device_id xgene_reboot_of_match[] = { |
72 | { .compatible = "apm,xgene-reboot" }, |
73 | {} |
74 | }; |
75 | |
76 | static 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 | }; |
83 | builtin_platform_driver(xgene_reboot_driver); |
84 | |