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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
50332639 AW |
2 | /* |
3 | * MEN 14F021P00 Board Management Controller (BMC) Watchdog Driver. | |
4 | * | |
5 | * Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH | |
50332639 AW |
6 | */ |
7 | ||
8 | #include <linux/kernel.h> | |
9 | #include <linux/device.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/watchdog.h> | |
12 | #include <linux/platform_device.h> | |
13 | #include <linux/i2c.h> | |
14 | ||
15 | #define DEVNAME "menf21bmc_wdt" | |
16 | ||
17 | #define BMC_CMD_WD_ON 0x11 | |
18 | #define BMC_CMD_WD_OFF 0x12 | |
19 | #define BMC_CMD_WD_TRIG 0x13 | |
20 | #define BMC_CMD_WD_TIME 0x14 | |
21 | #define BMC_CMD_WD_STATE 0x17 | |
22 | #define BMC_WD_OFF_VAL 0x69 | |
23 | #define BMC_CMD_RST_RSN 0x92 | |
24 | ||
25 | #define BMC_WD_TIMEOUT_MIN 1 /* in sec */ | |
26 | #define BMC_WD_TIMEOUT_MAX 6553 /* in sec */ | |
27 | ||
28 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
29 | module_param(nowayout, bool, 0); | |
30 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" | |
31 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
32 | ||
33 | struct menf21bmc_wdt { | |
34 | struct watchdog_device wdt; | |
35 | struct i2c_client *i2c_client; | |
36 | }; | |
37 | ||
38 | static int menf21bmc_wdt_set_bootstatus(struct menf21bmc_wdt *data) | |
39 | { | |
40 | int rst_rsn; | |
41 | ||
42 | rst_rsn = i2c_smbus_read_byte_data(data->i2c_client, BMC_CMD_RST_RSN); | |
43 | if (rst_rsn < 0) | |
44 | return rst_rsn; | |
45 | ||
46 | if (rst_rsn == 0x02) | |
47 | data->wdt.bootstatus |= WDIOF_CARDRESET; | |
48 | else if (rst_rsn == 0x05) | |
49 | data->wdt.bootstatus |= WDIOF_EXTERN1; | |
50 | else if (rst_rsn == 0x06) | |
51 | data->wdt.bootstatus |= WDIOF_EXTERN2; | |
52 | else if (rst_rsn == 0x0A) | |
53 | data->wdt.bootstatus |= WDIOF_POWERUNDER; | |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | static int menf21bmc_wdt_start(struct watchdog_device *wdt) | |
59 | { | |
60 | struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt); | |
61 | ||
62 | return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_ON); | |
63 | } | |
64 | ||
65 | static int menf21bmc_wdt_stop(struct watchdog_device *wdt) | |
66 | { | |
67 | struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt); | |
68 | ||
69 | return i2c_smbus_write_byte_data(drv_data->i2c_client, | |
70 | BMC_CMD_WD_OFF, BMC_WD_OFF_VAL); | |
71 | } | |
72 | ||
73 | static int | |
74 | menf21bmc_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout) | |
75 | { | |
76 | int ret; | |
77 | struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt); | |
78 | ||
79 | /* | |
80 | * BMC Watchdog does have a resolution of 100ms. | |
81 | * Watchdog API defines the timeout in seconds, so we have to | |
82 | * multiply the value. | |
83 | */ | |
84 | ret = i2c_smbus_write_word_data(drv_data->i2c_client, | |
85 | BMC_CMD_WD_TIME, timeout * 10); | |
86 | if (ret < 0) | |
87 | return ret; | |
88 | ||
89 | wdt->timeout = timeout; | |
90 | ||
91 | return 0; | |
92 | } | |
93 | ||
94 | static int menf21bmc_wdt_ping(struct watchdog_device *wdt) | |
95 | { | |
96 | struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt); | |
97 | ||
98 | return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_TRIG); | |
99 | } | |
100 | ||
101 | static const struct watchdog_info menf21bmc_wdt_info = { | |
102 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
103 | .identity = DEVNAME, | |
104 | }; | |
105 | ||
106 | static const struct watchdog_ops menf21bmc_wdt_ops = { | |
107 | .owner = THIS_MODULE, | |
108 | .start = menf21bmc_wdt_start, | |
109 | .stop = menf21bmc_wdt_stop, | |
110 | .ping = menf21bmc_wdt_ping, | |
111 | .set_timeout = menf21bmc_wdt_settimeout, | |
112 | }; | |
113 | ||
114 | static int menf21bmc_wdt_probe(struct platform_device *pdev) | |
115 | { | |
0c4ece9b | 116 | struct device *dev = &pdev->dev; |
50332639 AW |
117 | int ret, bmc_timeout; |
118 | struct menf21bmc_wdt *drv_data; | |
0c4ece9b | 119 | struct i2c_client *i2c_client = to_i2c_client(dev->parent); |
50332639 | 120 | |
0c4ece9b | 121 | drv_data = devm_kzalloc(dev, sizeof(struct menf21bmc_wdt), GFP_KERNEL); |
50332639 AW |
122 | if (!drv_data) |
123 | return -ENOMEM; | |
124 | ||
125 | drv_data->wdt.ops = &menf21bmc_wdt_ops; | |
126 | drv_data->wdt.info = &menf21bmc_wdt_info; | |
127 | drv_data->wdt.min_timeout = BMC_WD_TIMEOUT_MIN; | |
128 | drv_data->wdt.max_timeout = BMC_WD_TIMEOUT_MAX; | |
0c4ece9b | 129 | drv_data->wdt.parent = dev; |
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130 | drv_data->i2c_client = i2c_client; |
131 | ||
132 | /* | |
133 | * Get the current wdt timeout value from the BMC because | |
134 | * the BMC will save the value set before if the system restarts. | |
135 | */ | |
136 | bmc_timeout = i2c_smbus_read_word_data(drv_data->i2c_client, | |
137 | BMC_CMD_WD_TIME); | |
138 | if (bmc_timeout < 0) { | |
0c4ece9b | 139 | dev_err(dev, "failed to get current WDT timeout\n"); |
50332639 AW |
140 | return bmc_timeout; |
141 | } | |
142 | ||
0c4ece9b | 143 | watchdog_init_timeout(&drv_data->wdt, bmc_timeout / 10, dev); |
50332639 AW |
144 | watchdog_set_nowayout(&drv_data->wdt, nowayout); |
145 | watchdog_set_drvdata(&drv_data->wdt, drv_data); | |
146 | platform_set_drvdata(pdev, drv_data); | |
147 | ||
148 | ret = menf21bmc_wdt_set_bootstatus(drv_data); | |
149 | if (ret < 0) { | |
0c4ece9b | 150 | dev_err(dev, "failed to set Watchdog bootstatus\n"); |
50332639 AW |
151 | return ret; |
152 | } | |
153 | ||
0c4ece9b | 154 | ret = devm_watchdog_register_device(dev, &drv_data->wdt); |
50332639 | 155 | if (ret) { |
0c4ece9b | 156 | dev_err(dev, "failed to register Watchdog device\n"); |
50332639 AW |
157 | return ret; |
158 | } | |
159 | ||
0c4ece9b | 160 | dev_info(dev, "MEN 14F021P00 BMC Watchdog device enabled\n"); |
50332639 AW |
161 | |
162 | return 0; | |
163 | } | |
164 | ||
165 | static void menf21bmc_wdt_shutdown(struct platform_device *pdev) | |
166 | { | |
167 | struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev); | |
168 | ||
169 | i2c_smbus_write_word_data(drv_data->i2c_client, | |
170 | BMC_CMD_WD_OFF, BMC_WD_OFF_VAL); | |
171 | } | |
172 | ||
173 | static struct platform_driver menf21bmc_wdt = { | |
174 | .driver = { | |
50332639 AW |
175 | .name = DEVNAME, |
176 | }, | |
177 | .probe = menf21bmc_wdt_probe, | |
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178 | .shutdown = menf21bmc_wdt_shutdown, |
179 | }; | |
180 | ||
181 | module_platform_driver(menf21bmc_wdt); | |
182 | ||
183 | MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver"); | |
184 | MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>"); | |
185 | MODULE_LICENSE("GPL v2"); | |
186 | MODULE_ALIAS("platform:menf21bmc_wdt"); |