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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
26#define BMC_WD_TIMEOUT_MAX 6553
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
81
82
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
134
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");
185
