Commit | Line | Data |
---|---|---|
50332639 AW |
1 | /* |
2 | * MEN 14F021P00 Board Management Controller (BMC) Watchdog Driver. | |
3 | * | |
4 | * Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the | |
8 | * Free Software Foundation; either version 2 of the License, or (at your | |
9 | * option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/device.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/watchdog.h> | |
16 | #include <linux/platform_device.h> | |
17 | #include <linux/i2c.h> | |
18 | ||
19 | #define DEVNAME "menf21bmc_wdt" | |
20 | ||
21 | #define BMC_CMD_WD_ON 0x11 | |
22 | #define BMC_CMD_WD_OFF 0x12 | |
23 | #define BMC_CMD_WD_TRIG 0x13 | |
24 | #define BMC_CMD_WD_TIME 0x14 | |
25 | #define BMC_CMD_WD_STATE 0x17 | |
26 | #define BMC_WD_OFF_VAL 0x69 | |
27 | #define BMC_CMD_RST_RSN 0x92 | |
28 | ||
29 | #define BMC_WD_TIMEOUT_MIN 1 /* in sec */ | |
30 | #define BMC_WD_TIMEOUT_MAX 6553 /* in sec */ | |
31 | ||
32 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
33 | module_param(nowayout, bool, 0); | |
34 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" | |
35 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
36 | ||
37 | struct menf21bmc_wdt { | |
38 | struct watchdog_device wdt; | |
39 | struct i2c_client *i2c_client; | |
40 | }; | |
41 | ||
42 | static int menf21bmc_wdt_set_bootstatus(struct menf21bmc_wdt *data) | |
43 | { | |
44 | int rst_rsn; | |
45 | ||
46 | rst_rsn = i2c_smbus_read_byte_data(data->i2c_client, BMC_CMD_RST_RSN); | |
47 | if (rst_rsn < 0) | |
48 | return rst_rsn; | |
49 | ||
50 | if (rst_rsn == 0x02) | |
51 | data->wdt.bootstatus |= WDIOF_CARDRESET; | |
52 | else if (rst_rsn == 0x05) | |
53 | data->wdt.bootstatus |= WDIOF_EXTERN1; | |
54 | else if (rst_rsn == 0x06) | |
55 | data->wdt.bootstatus |= WDIOF_EXTERN2; | |
56 | else if (rst_rsn == 0x0A) | |
57 | data->wdt.bootstatus |= WDIOF_POWERUNDER; | |
58 | ||
59 | return 0; | |
60 | } | |
61 | ||
62 | static int menf21bmc_wdt_start(struct watchdog_device *wdt) | |
63 | { | |
64 | struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt); | |
65 | ||
66 | return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_ON); | |
67 | } | |
68 | ||
69 | static int menf21bmc_wdt_stop(struct watchdog_device *wdt) | |
70 | { | |
71 | struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt); | |
72 | ||
73 | return i2c_smbus_write_byte_data(drv_data->i2c_client, | |
74 | BMC_CMD_WD_OFF, BMC_WD_OFF_VAL); | |
75 | } | |
76 | ||
77 | static int | |
78 | menf21bmc_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout) | |
79 | { | |
80 | int ret; | |
81 | struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt); | |
82 | ||
83 | /* | |
84 | * BMC Watchdog does have a resolution of 100ms. | |
85 | * Watchdog API defines the timeout in seconds, so we have to | |
86 | * multiply the value. | |
87 | */ | |
88 | ret = i2c_smbus_write_word_data(drv_data->i2c_client, | |
89 | BMC_CMD_WD_TIME, timeout * 10); | |
90 | if (ret < 0) | |
91 | return ret; | |
92 | ||
93 | wdt->timeout = timeout; | |
94 | ||
95 | return 0; | |
96 | } | |
97 | ||
98 | static int menf21bmc_wdt_ping(struct watchdog_device *wdt) | |
99 | { | |
100 | struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt); | |
101 | ||
102 | return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_TRIG); | |
103 | } | |
104 | ||
105 | static const struct watchdog_info menf21bmc_wdt_info = { | |
106 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
107 | .identity = DEVNAME, | |
108 | }; | |
109 | ||
110 | static const struct watchdog_ops menf21bmc_wdt_ops = { | |
111 | .owner = THIS_MODULE, | |
112 | .start = menf21bmc_wdt_start, | |
113 | .stop = menf21bmc_wdt_stop, | |
114 | .ping = menf21bmc_wdt_ping, | |
115 | .set_timeout = menf21bmc_wdt_settimeout, | |
116 | }; | |
117 | ||
118 | static int menf21bmc_wdt_probe(struct platform_device *pdev) | |
119 | { | |
120 | int ret, bmc_timeout; | |
121 | struct menf21bmc_wdt *drv_data; | |
122 | struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent); | |
123 | ||
124 | drv_data = devm_kzalloc(&pdev->dev, | |
125 | sizeof(struct menf21bmc_wdt), GFP_KERNEL); | |
126 | if (!drv_data) | |
127 | return -ENOMEM; | |
128 | ||
129 | drv_data->wdt.ops = &menf21bmc_wdt_ops; | |
130 | drv_data->wdt.info = &menf21bmc_wdt_info; | |
131 | drv_data->wdt.min_timeout = BMC_WD_TIMEOUT_MIN; | |
132 | drv_data->wdt.max_timeout = BMC_WD_TIMEOUT_MAX; | |
133 | drv_data->i2c_client = i2c_client; | |
134 | ||
135 | /* | |
136 | * Get the current wdt timeout value from the BMC because | |
137 | * the BMC will save the value set before if the system restarts. | |
138 | */ | |
139 | bmc_timeout = i2c_smbus_read_word_data(drv_data->i2c_client, | |
140 | BMC_CMD_WD_TIME); | |
141 | if (bmc_timeout < 0) { | |
142 | dev_err(&pdev->dev, "failed to get current WDT timeout\n"); | |
143 | return bmc_timeout; | |
144 | } | |
145 | ||
146 | watchdog_init_timeout(&drv_data->wdt, bmc_timeout / 10, &pdev->dev); | |
147 | watchdog_set_nowayout(&drv_data->wdt, nowayout); | |
148 | watchdog_set_drvdata(&drv_data->wdt, drv_data); | |
149 | platform_set_drvdata(pdev, drv_data); | |
150 | ||
151 | ret = menf21bmc_wdt_set_bootstatus(drv_data); | |
152 | if (ret < 0) { | |
153 | dev_err(&pdev->dev, "failed to set Watchdog bootstatus\n"); | |
154 | return ret; | |
155 | } | |
156 | ||
157 | ret = watchdog_register_device(&drv_data->wdt); | |
158 | if (ret) { | |
159 | dev_err(&pdev->dev, "failed to register Watchdog device\n"); | |
160 | return ret; | |
161 | } | |
162 | ||
163 | dev_info(&pdev->dev, "MEN 14F021P00 BMC Watchdog device enabled\n"); | |
164 | ||
165 | return 0; | |
166 | } | |
167 | ||
168 | static int menf21bmc_wdt_remove(struct platform_device *pdev) | |
169 | { | |
170 | struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev); | |
171 | ||
172 | dev_warn(&pdev->dev, | |
173 | "Unregister MEN 14F021P00 BMC Watchdog device, board may reset\n"); | |
174 | ||
175 | watchdog_unregister_device(&drv_data->wdt); | |
176 | ||
177 | return 0; | |
178 | } | |
179 | ||
180 | static void menf21bmc_wdt_shutdown(struct platform_device *pdev) | |
181 | { | |
182 | struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev); | |
183 | ||
184 | i2c_smbus_write_word_data(drv_data->i2c_client, | |
185 | BMC_CMD_WD_OFF, BMC_WD_OFF_VAL); | |
186 | } | |
187 | ||
188 | static struct platform_driver menf21bmc_wdt = { | |
189 | .driver = { | |
50332639 AW |
190 | .name = DEVNAME, |
191 | }, | |
192 | .probe = menf21bmc_wdt_probe, | |
193 | .remove = menf21bmc_wdt_remove, | |
194 | .shutdown = menf21bmc_wdt_shutdown, | |
195 | }; | |
196 | ||
197 | module_platform_driver(menf21bmc_wdt); | |
198 | ||
199 | MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver"); | |
200 | MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>"); | |
201 | MODULE_LICENSE("GPL v2"); | |
202 | MODULE_ALIAS("platform:menf21bmc_wdt"); |