th1520-aon-reboot.c

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * T-HEAD TH1520 AON Firmware Reboot Driver
 4 *
 5 * Copyright (c) 2025 Icenowy Zheng <uwu@icenowy.me>
 6 */
 7
 8#include <linux/auxiliary_bus.h>
 9#include <linux/firmware/thead/thead,th1520-aon.h>
10#include <linux/module.h>
11#include <linux/notifier.h>
12#include <linux/of.h>
13#include <linux/reboot.h>
14#include <linux/slab.h>
15
16#define TH1520_AON_REBOOT_PRIORITY 200
17
18struct th1520_aon_msg_empty_body {
19	struct th1520_aon_rpc_msg_hdr hdr;
20	u16 reserved[12];
21} __packed __aligned(1);
22
23static int th1520_aon_pwroff_handler(struct sys_off_data *data)
24{
25	struct th1520_aon_chan *aon_chan = data->cb_data;
26	struct th1520_aon_msg_empty_body msg = {};
27
28	msg.hdr.svc = TH1520_AON_RPC_SVC_WDG;
29	msg.hdr.func = TH1520_AON_WDG_FUNC_POWER_OFF;
30	msg.hdr.size = TH1520_AON_RPC_MSG_NUM;
31
32	th1520_aon_call_rpc(aon_chan, &msg);
33
34	return NOTIFY_DONE;
35}
36
37static int th1520_aon_restart_handler(struct sys_off_data *data)
38{
39	struct th1520_aon_chan *aon_chan = data->cb_data;
40	struct th1520_aon_msg_empty_body msg = {};
41
42	msg.hdr.svc = TH1520_AON_RPC_SVC_WDG;
43	msg.hdr.func = TH1520_AON_WDG_FUNC_RESTART;
44	msg.hdr.size = TH1520_AON_RPC_MSG_NUM;
45
46	th1520_aon_call_rpc(aon_chan, &msg);
47
48	return NOTIFY_DONE;
49}
50
51static int th1520_aon_reboot_probe(struct auxiliary_device *adev,
52				  const struct auxiliary_device_id *id)
53{
54	struct device *dev = &adev->dev;
55	int ret;
56
57	/* Expect struct th1520_aon_chan to be passed via platform_data */
58	ret = devm_register_sys_off_handler(dev, SYS_OFF_MODE_POWER_OFF,
59					    TH1520_AON_REBOOT_PRIORITY,
60					    th1520_aon_pwroff_handler,
61					    adev->dev.platform_data);
62
63	if (ret) {
64		dev_err(dev, "Failed to register power off handler\n");
65		return ret;
66	}
67
68	ret = devm_register_sys_off_handler(dev, SYS_OFF_MODE_RESTART,
69					    TH1520_AON_REBOOT_PRIORITY,
70					    th1520_aon_restart_handler,
71					    adev->dev.platform_data);
72
73	if (ret) {
74		dev_err(dev, "Failed to register restart handler\n");
75		return ret;
76	}
77
78	return 0;
79}
80
81static const struct auxiliary_device_id th1520_aon_reboot_id_table[] = {
82	{ .name = "th1520_pm_domains.reboot" },
83	{},
84};
85MODULE_DEVICE_TABLE(auxiliary, th1520_aon_reboot_id_table);
86
87static struct auxiliary_driver th1520_aon_reboot_driver = {
88	.driver = {
89		.name = "th1520-aon-reboot",
90	},
91	.probe = th1520_aon_reboot_probe,
92	.id_table = th1520_aon_reboot_id_table,
93};
94module_auxiliary_driver(th1520_aon_reboot_driver);
95
96MODULE_AUTHOR("Icenowy Zheng <uwu@icenowy.me>");
97MODULE_DESCRIPTION("T-HEAD TH1520 AON-firmware-based reboot driver");
98MODULE_LICENSE("GPL");