1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright 2024 Google LLC. |
4 | * Author: Lukasz Majczak <lma@chromium.com> |
5 | */ |
6 | |
7 | #include <linux/err.h> |
8 | #include <linux/kernel.h> |
9 | #include <linux/module.h> |
10 | #include <linux/mod_devicetable.h> |
11 | #include <linux/platform_data/cros_ec_commands.h> |
12 | #include <linux/platform_data/cros_ec_proto.h> |
13 | #include <linux/platform_device.h> |
14 | #include <linux/watchdog.h> |
15 | |
16 | #define CROS_EC_WATCHDOG_DEFAULT_TIME 30 /* seconds */ |
17 | #define DRV_NAME "cros-ec-wdt" |
18 | |
19 | union cros_ec_wdt_data { |
20 | struct ec_params_hang_detect req; |
21 | struct ec_response_hang_detect resp; |
22 | } __packed; |
23 | |
24 | static int cros_ec_wdt_send_cmd(struct cros_ec_device *cros_ec, |
25 | union cros_ec_wdt_data *arg) |
26 | { |
27 | int ret; |
28 | struct { |
29 | struct cros_ec_command msg; |
30 | union cros_ec_wdt_data data; |
31 | } __packed buf = { |
32 | .msg = { |
33 | .version = 0, |
34 | .command = EC_CMD_HANG_DETECT, |
35 | .insize = (arg->req.command == EC_HANG_DETECT_CMD_GET_STATUS) ? |
36 | sizeof(struct ec_response_hang_detect) : |
37 | 0, |
38 | .outsize = sizeof(struct ec_params_hang_detect), |
39 | }, |
40 | .data.req = arg->req |
41 | }; |
42 | |
43 | ret = cros_ec_cmd_xfer_status(ec_dev: cros_ec, msg: &buf.msg); |
44 | if (ret < 0) |
45 | return ret; |
46 | |
47 | arg->resp = buf.data.resp; |
48 | |
49 | return 0; |
50 | } |
51 | |
52 | static int cros_ec_wdt_ping(struct watchdog_device *wdd) |
53 | { |
54 | struct cros_ec_device *cros_ec = watchdog_get_drvdata(wdd); |
55 | union cros_ec_wdt_data arg; |
56 | int ret; |
57 | |
58 | arg.req.command = EC_HANG_DETECT_CMD_RELOAD; |
59 | ret = cros_ec_wdt_send_cmd(cros_ec, arg: &arg); |
60 | if (ret < 0) |
61 | dev_dbg(wdd->parent, "Failed to ping watchdog (%d)" , ret); |
62 | |
63 | return ret; |
64 | } |
65 | |
66 | static int cros_ec_wdt_start(struct watchdog_device *wdd) |
67 | { |
68 | struct cros_ec_device *cros_ec = watchdog_get_drvdata(wdd); |
69 | union cros_ec_wdt_data arg; |
70 | int ret; |
71 | |
72 | /* Prepare watchdog on EC side */ |
73 | arg.req.command = EC_HANG_DETECT_CMD_SET_TIMEOUT; |
74 | arg.req.reboot_timeout_sec = wdd->timeout; |
75 | ret = cros_ec_wdt_send_cmd(cros_ec, arg: &arg); |
76 | if (ret < 0) |
77 | dev_dbg(wdd->parent, "Failed to start watchdog (%d)" , ret); |
78 | |
79 | return ret; |
80 | } |
81 | |
82 | static int cros_ec_wdt_stop(struct watchdog_device *wdd) |
83 | { |
84 | struct cros_ec_device *cros_ec = watchdog_get_drvdata(wdd); |
85 | union cros_ec_wdt_data arg; |
86 | int ret; |
87 | |
88 | arg.req.command = EC_HANG_DETECT_CMD_CANCEL; |
89 | ret = cros_ec_wdt_send_cmd(cros_ec, arg: &arg); |
90 | if (ret < 0) |
91 | dev_dbg(wdd->parent, "Failed to stop watchdog (%d)" , ret); |
92 | |
93 | return ret; |
94 | } |
95 | |
96 | static int cros_ec_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t) |
97 | { |
98 | unsigned int old_timeout = wdd->timeout; |
99 | int ret; |
100 | |
101 | wdd->timeout = t; |
102 | ret = cros_ec_wdt_start(wdd); |
103 | if (ret < 0) |
104 | wdd->timeout = old_timeout; |
105 | |
106 | return ret; |
107 | } |
108 | |
109 | static const struct watchdog_info cros_ec_wdt_ident = { |
110 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, |
111 | .firmware_version = 0, |
112 | .identity = DRV_NAME, |
113 | }; |
114 | |
115 | static const struct watchdog_ops cros_ec_wdt_ops = { |
116 | .owner = THIS_MODULE, |
117 | .ping = cros_ec_wdt_ping, |
118 | .start = cros_ec_wdt_start, |
119 | .stop = cros_ec_wdt_stop, |
120 | .set_timeout = cros_ec_wdt_set_timeout, |
121 | }; |
122 | |
123 | static int cros_ec_wdt_probe(struct platform_device *pdev) |
124 | { |
125 | struct device *dev = &pdev->dev; |
126 | struct cros_ec_dev *ec_dev = dev_get_drvdata(dev: dev->parent); |
127 | struct cros_ec_device *cros_ec = ec_dev->ec_dev; |
128 | struct watchdog_device *wdd; |
129 | union cros_ec_wdt_data arg; |
130 | int ret = 0; |
131 | |
132 | wdd = devm_kzalloc(dev: &pdev->dev, size: sizeof(*wdd), GFP_KERNEL); |
133 | if (!wdd) |
134 | return -ENOMEM; |
135 | |
136 | arg.req.command = EC_HANG_DETECT_CMD_GET_STATUS; |
137 | ret = cros_ec_wdt_send_cmd(cros_ec, arg: &arg); |
138 | if (ret < 0) |
139 | return dev_err_probe(dev, err: ret, fmt: "Failed to get watchdog bootstatus" ); |
140 | |
141 | wdd->parent = &pdev->dev; |
142 | wdd->info = &cros_ec_wdt_ident; |
143 | wdd->ops = &cros_ec_wdt_ops; |
144 | wdd->timeout = CROS_EC_WATCHDOG_DEFAULT_TIME; |
145 | wdd->min_timeout = EC_HANG_DETECT_MIN_TIMEOUT; |
146 | wdd->max_timeout = EC_HANG_DETECT_MAX_TIMEOUT; |
147 | if (arg.resp.status == EC_HANG_DETECT_AP_BOOT_EC_WDT) |
148 | wdd->bootstatus = WDIOF_CARDRESET; |
149 | |
150 | arg.req.command = EC_HANG_DETECT_CMD_CLEAR_STATUS; |
151 | ret = cros_ec_wdt_send_cmd(cros_ec, arg: &arg); |
152 | if (ret < 0) |
153 | return dev_err_probe(dev, err: ret, fmt: "Failed to clear watchdog bootstatus" ); |
154 | |
155 | watchdog_stop_on_reboot(wdd); |
156 | watchdog_stop_on_unregister(wdd); |
157 | watchdog_set_drvdata(wdd, data: cros_ec); |
158 | platform_set_drvdata(pdev, data: wdd); |
159 | |
160 | return devm_watchdog_register_device(dev, wdd); |
161 | } |
162 | |
163 | static int __maybe_unused cros_ec_wdt_suspend(struct platform_device *pdev, pm_message_t state) |
164 | { |
165 | struct watchdog_device *wdd = platform_get_drvdata(pdev); |
166 | int ret = 0; |
167 | |
168 | if (watchdog_active(wdd)) |
169 | ret = cros_ec_wdt_stop(wdd); |
170 | |
171 | return ret; |
172 | } |
173 | |
174 | static int __maybe_unused cros_ec_wdt_resume(struct platform_device *pdev) |
175 | { |
176 | struct watchdog_device *wdd = platform_get_drvdata(pdev); |
177 | int ret = 0; |
178 | |
179 | if (watchdog_active(wdd)) |
180 | ret = cros_ec_wdt_start(wdd); |
181 | |
182 | return ret; |
183 | } |
184 | |
185 | static const struct platform_device_id cros_ec_wdt_id[] = { |
186 | { DRV_NAME, 0 }, |
187 | {} |
188 | }; |
189 | |
190 | static struct platform_driver cros_ec_wdt_driver = { |
191 | .probe = cros_ec_wdt_probe, |
192 | .suspend = pm_ptr(cros_ec_wdt_suspend), |
193 | .resume = pm_ptr(cros_ec_wdt_resume), |
194 | .driver = { |
195 | .name = DRV_NAME, |
196 | }, |
197 | .id_table = cros_ec_wdt_id, |
198 | }; |
199 | |
200 | module_platform_driver(cros_ec_wdt_driver); |
201 | |
202 | MODULE_DEVICE_TABLE(platform, cros_ec_wdt_id); |
203 | MODULE_DESCRIPTION("Cros EC Watchdog Device Driver" ); |
204 | MODULE_LICENSE("GPL" ); |
205 | |