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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * MEN 14F021P00 Board Management Controller (BMC) Watchdog Driver.
4 *
5 * Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
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
28static bool nowayout = WATCHDOG_NOWAYOUT;
29module_param(nowayout, bool, 0);
30MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
31 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
32
33struct menf21bmc_wdt {
34 struct watchdog_device wdt;
35 struct i2c_client *i2c_client;
36};
37
38static 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
58static 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
65static 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
73static int
74menf21bmc_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
94static 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
101static const struct watchdog_info menf21bmc_wdt_info = {
102 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
103 .identity = DEVNAME,
104};
105
106static 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
114static int menf21bmc_wdt_probe(struct platform_device *pdev)
115{
116 struct device *dev = &pdev->dev;
117 int ret, bmc_timeout;
118 struct menf21bmc_wdt *drv_data;
119 struct i2c_client *i2c_client = to_i2c_client(dev->parent);
120
121 drv_data = devm_kzalloc(dev, sizeof(struct menf21bmc_wdt), GFP_KERNEL);
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;
129 drv_data->wdt.parent = dev;
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) {
139 dev_err(dev, "failed to get current WDT timeout\n");
140 return bmc_timeout;
141 }
142
143 watchdog_init_timeout(&drv_data->wdt, bmc_timeout / 10, dev);
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) {
150 dev_err(dev, "failed to set Watchdog bootstatus\n");
151 return ret;
152 }
153
154 ret = devm_watchdog_register_device(dev, &drv_data->wdt);
155 if (ret)
156 return ret;
157
158 dev_info(dev, "MEN 14F021P00 BMC Watchdog device enabled\n");
159
160 return 0;
161}
162
163static void menf21bmc_wdt_shutdown(struct platform_device *pdev)
164{
165 struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
166
167 i2c_smbus_write_word_data(drv_data->i2c_client,
168 BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
169}
170
171static struct platform_driver menf21bmc_wdt = {
172 .driver = {
173 .name = DEVNAME,
174 },
175 .probe = menf21bmc_wdt_probe,
176 .shutdown = menf21bmc_wdt_shutdown,
177};
178
179module_platform_driver(menf21bmc_wdt);
180
181MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver");
182MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
183MODULE_LICENSE("GPL v2");
184MODULE_ALIAS("platform:menf21bmc_wdt");
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
32static bool nowayout = WATCHDOG_NOWAYOUT;
33module_param(nowayout, bool, 0);
34MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
35 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
36
37struct menf21bmc_wdt {
38 struct watchdog_device wdt;
39 struct i2c_client *i2c_client;
40};
41
42static 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
62static 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
69static 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
77static int
78menf21bmc_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
98static 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
105static const struct watchdog_info menf21bmc_wdt_info = {
106 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
107 .identity = DEVNAME,
108};
109
110static 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
118static 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->wdt.parent = &pdev->dev;
134 drv_data->i2c_client = i2c_client;
135
136 /*
137 * Get the current wdt timeout value from the BMC because
138 * the BMC will save the value set before if the system restarts.
139 */
140 bmc_timeout = i2c_smbus_read_word_data(drv_data->i2c_client,
141 BMC_CMD_WD_TIME);
142 if (bmc_timeout < 0) {
143 dev_err(&pdev->dev, "failed to get current WDT timeout\n");
144 return bmc_timeout;
145 }
146
147 watchdog_init_timeout(&drv_data->wdt, bmc_timeout / 10, &pdev->dev);
148 watchdog_set_nowayout(&drv_data->wdt, nowayout);
149 watchdog_set_drvdata(&drv_data->wdt, drv_data);
150 platform_set_drvdata(pdev, drv_data);
151
152 ret = menf21bmc_wdt_set_bootstatus(drv_data);
153 if (ret < 0) {
154 dev_err(&pdev->dev, "failed to set Watchdog bootstatus\n");
155 return ret;
156 }
157
158 ret = watchdog_register_device(&drv_data->wdt);
159 if (ret) {
160 dev_err(&pdev->dev, "failed to register Watchdog device\n");
161 return ret;
162 }
163
164 dev_info(&pdev->dev, "MEN 14F021P00 BMC Watchdog device enabled\n");
165
166 return 0;
167}
168
169static int menf21bmc_wdt_remove(struct platform_device *pdev)
170{
171 struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
172
173 dev_warn(&pdev->dev,
174 "Unregister MEN 14F021P00 BMC Watchdog device, board may reset\n");
175
176 watchdog_unregister_device(&drv_data->wdt);
177
178 return 0;
179}
180
181static void menf21bmc_wdt_shutdown(struct platform_device *pdev)
182{
183 struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
184
185 i2c_smbus_write_word_data(drv_data->i2c_client,
186 BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
187}
188
189static struct platform_driver menf21bmc_wdt = {
190 .driver = {
191 .name = DEVNAME,
192 },
193 .probe = menf21bmc_wdt_probe,
194 .remove = menf21bmc_wdt_remove,
195 .shutdown = menf21bmc_wdt_shutdown,
196};
197
198module_platform_driver(menf21bmc_wdt);
199
200MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver");
201MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
202MODULE_LICENSE("GPL v2");
203MODULE_ALIAS("platform:menf21bmc_wdt");