1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Mellanox watchdog driver
4 *
5 * Copyright (C) 2019 Mellanox Technologies
6 * Copyright (C) 2019 Michael Shych <mshych@mellanox.com>
7 */
8
9 #include <linux/bitops.h>
10 #include <linux/device.h>
11 #include <linux/errno.h>
12 #include <linux/log2.h>
13 #include <linux/module.h>
14 #include <linux/platform_data/mlxreg.h>
15 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
17 #include <linux/spinlock.h>
18 #include <linux/types.h>
19 #include <linux/watchdog.h>
20
21 #define MLXREG_WDT_CLOCK_SCALE 1000
22 #define MLXREG_WDT_MAX_TIMEOUT_TYPE1 32
23 #define MLXREG_WDT_MAX_TIMEOUT_TYPE2 255
24 #define MLXREG_WDT_MAX_TIMEOUT_TYPE3 65535
25 #define MLXREG_WDT_MIN_TIMEOUT 1
26 #define MLXREG_WDT_OPTIONS_BASE (WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | \
27 WDIOF_SETTIMEOUT)
28
29 /**
30 * struct mlxreg_wdt - wd private data:
31 *
32 * @wdd: watchdog device;
33 * @pdata: data received from platform driver;
34 * @regmap: register map of parent device;
35 * @action_idx: index for direct access to action register;
36 * @timeout_idx:index for direct access to TO register;
37 * @tleft_idx: index for direct access to time left register;
38 * @ping_idx: index for direct access to ping register;
39 * @reset_idx: index for direct access to reset cause register;
40 * @regmap_val_sz: size of value in register map;
41 * @wdt_type: watchdog HW type;
42 */
43 struct mlxreg_wdt {
44 struct watchdog_device wdd;
45 struct mlxreg_core_platform_data *pdata;
46 void *regmap;
47 int action_idx;
48 int timeout_idx;
49 int tleft_idx;
50 int ping_idx;
51 int reset_idx;
52 int regmap_val_sz;
53 enum mlxreg_wdt_type wdt_type;
54 };
55
mlxreg_wdt_check_card_reset(struct mlxreg_wdt * wdt)56 static void mlxreg_wdt_check_card_reset(struct mlxreg_wdt *wdt)
57 {
58 struct mlxreg_core_data *reg_data;
59 u32 regval;
60 int rc;
61
62 if (wdt->reset_idx == -EINVAL)
63 return;
64
65 if (!(wdt->wdd.info->options & WDIOF_CARDRESET))
66 return;
67
68 reg_data = &wdt->pdata->data[wdt->reset_idx];
69 rc = regmap_read(wdt->regmap, reg_data->reg, ®val);
70 if (!rc) {
71 if (regval & ~reg_data->mask) {
72 wdt->wdd.bootstatus = WDIOF_CARDRESET;
73 dev_info(wdt->wdd.parent,
74 "watchdog previously reset the CPU\n");
75 }
76 }
77 }
78
mlxreg_wdt_start(struct watchdog_device * wdd)79 static int mlxreg_wdt_start(struct watchdog_device *wdd)
80 {
81 struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
82 struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->action_idx];
83
84 return regmap_update_bits(wdt->regmap, reg_data->reg, ~reg_data->mask,
85 BIT(reg_data->bit));
86 }
87
mlxreg_wdt_stop(struct watchdog_device * wdd)88 static int mlxreg_wdt_stop(struct watchdog_device *wdd)
89 {
90 struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
91 struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->action_idx];
92
93 return regmap_update_bits(wdt->regmap, reg_data->reg, ~reg_data->mask,
94 ~BIT(reg_data->bit));
95 }
96
mlxreg_wdt_ping(struct watchdog_device * wdd)97 static int mlxreg_wdt_ping(struct watchdog_device *wdd)
98 {
99 struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
100 struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->ping_idx];
101
102 return regmap_write_bits(wdt->regmap, reg_data->reg, ~reg_data->mask,
103 BIT(reg_data->bit));
104 }
105
mlxreg_wdt_set_timeout(struct watchdog_device * wdd,unsigned int timeout)106 static int mlxreg_wdt_set_timeout(struct watchdog_device *wdd,
107 unsigned int timeout)
108 {
109 struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
110 struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->timeout_idx];
111 u32 regval, set_time, hw_timeout;
112 int rc;
113
114 switch (wdt->wdt_type) {
115 case MLX_WDT_TYPE1:
116 rc = regmap_read(wdt->regmap, reg_data->reg, ®val);
117 if (rc)
118 return rc;
119
120 hw_timeout = order_base_2(timeout * MLXREG_WDT_CLOCK_SCALE);
121 regval = (regval & reg_data->mask) | hw_timeout;
122 /* Rowndown to actual closest number of sec. */
123 set_time = BIT(hw_timeout) / MLXREG_WDT_CLOCK_SCALE;
124 rc = regmap_write(wdt->regmap, reg_data->reg, regval);
125 break;
126 case MLX_WDT_TYPE2:
127 set_time = timeout;
128 rc = regmap_write(wdt->regmap, reg_data->reg, timeout);
129 break;
130 case MLX_WDT_TYPE3:
131 /* WD_TYPE3 has 2B set time register */
132 set_time = timeout;
133 if (wdt->regmap_val_sz == 1) {
134 regval = timeout & 0xff;
135 rc = regmap_write(wdt->regmap, reg_data->reg, regval);
136 if (!rc) {
137 regval = (timeout & 0xff00) >> 8;
138 rc = regmap_write(wdt->regmap,
139 reg_data->reg + 1, regval);
140 }
141 } else {
142 rc = regmap_write(wdt->regmap, reg_data->reg, timeout);
143 }
144 break;
145 default:
146 return -EINVAL;
147 }
148
149 wdd->timeout = set_time;
150 if (!rc) {
151 /*
152 * Restart watchdog with new timeout period
153 * if watchdog is already started.
154 */
155 if (watchdog_active(wdd)) {
156 rc = mlxreg_wdt_stop(wdd);
157 if (!rc)
158 rc = mlxreg_wdt_start(wdd);
159 }
160 }
161
162 return rc;
163 }
164
mlxreg_wdt_get_timeleft(struct watchdog_device * wdd)165 static unsigned int mlxreg_wdt_get_timeleft(struct watchdog_device *wdd)
166 {
167 struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
168 struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->tleft_idx];
169 u32 regval, msb, lsb;
170 int rc;
171
172 if (wdt->wdt_type == MLX_WDT_TYPE2) {
173 rc = regmap_read(wdt->regmap, reg_data->reg, ®val);
174 } else {
175 /* WD_TYPE3 has 2 byte timeleft register */
176 if (wdt->regmap_val_sz == 1) {
177 rc = regmap_read(wdt->regmap, reg_data->reg, &lsb);
178 if (!rc) {
179 rc = regmap_read(wdt->regmap,
180 reg_data->reg + 1, &msb);
181 regval = (msb & 0xff) << 8 | (lsb & 0xff);
182 }
183 } else {
184 rc = regmap_read(wdt->regmap, reg_data->reg, ®val);
185 }
186 }
187
188 /* Return 0 timeleft in case of failure register read. */
189 return rc == 0 ? regval : 0;
190 }
191
192 static const struct watchdog_ops mlxreg_wdt_ops_type1 = {
193 .start = mlxreg_wdt_start,
194 .stop = mlxreg_wdt_stop,
195 .ping = mlxreg_wdt_ping,
196 .set_timeout = mlxreg_wdt_set_timeout,
197 .owner = THIS_MODULE,
198 };
199
200 static const struct watchdog_ops mlxreg_wdt_ops_type2 = {
201 .start = mlxreg_wdt_start,
202 .stop = mlxreg_wdt_stop,
203 .ping = mlxreg_wdt_ping,
204 .set_timeout = mlxreg_wdt_set_timeout,
205 .get_timeleft = mlxreg_wdt_get_timeleft,
206 .owner = THIS_MODULE,
207 };
208
209 static const struct watchdog_info mlxreg_wdt_main_info = {
210 .options = MLXREG_WDT_OPTIONS_BASE
211 | WDIOF_CARDRESET,
212 .identity = "mlx-wdt-main",
213 };
214
215 static const struct watchdog_info mlxreg_wdt_aux_info = {
216 .options = MLXREG_WDT_OPTIONS_BASE
217 | WDIOF_ALARMONLY,
218 .identity = "mlx-wdt-aux",
219 };
220
mlxreg_wdt_config(struct mlxreg_wdt * wdt,struct mlxreg_core_platform_data * pdata)221 static void mlxreg_wdt_config(struct mlxreg_wdt *wdt,
222 struct mlxreg_core_platform_data *pdata)
223 {
224 struct mlxreg_core_data *data = pdata->data;
225 int i;
226
227 wdt->reset_idx = -EINVAL;
228 for (i = 0; i < pdata->counter; i++, data++) {
229 if (strnstr(data->label, "action", sizeof(data->label)))
230 wdt->action_idx = i;
231 else if (strnstr(data->label, "timeout", sizeof(data->label)))
232 wdt->timeout_idx = i;
233 else if (strnstr(data->label, "timeleft", sizeof(data->label)))
234 wdt->tleft_idx = i;
235 else if (strnstr(data->label, "ping", sizeof(data->label)))
236 wdt->ping_idx = i;
237 else if (strnstr(data->label, "reset", sizeof(data->label)))
238 wdt->reset_idx = i;
239 }
240
241 wdt->pdata = pdata;
242 if (strnstr(pdata->identity, mlxreg_wdt_main_info.identity,
243 sizeof(mlxreg_wdt_main_info.identity)))
244 wdt->wdd.info = &mlxreg_wdt_main_info;
245 else
246 wdt->wdd.info = &mlxreg_wdt_aux_info;
247
248 wdt->wdt_type = pdata->version;
249 switch (wdt->wdt_type) {
250 case MLX_WDT_TYPE1:
251 wdt->wdd.ops = &mlxreg_wdt_ops_type1;
252 wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE1;
253 break;
254 case MLX_WDT_TYPE2:
255 wdt->wdd.ops = &mlxreg_wdt_ops_type2;
256 wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE2;
257 break;
258 case MLX_WDT_TYPE3:
259 wdt->wdd.ops = &mlxreg_wdt_ops_type2;
260 wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE3;
261 break;
262 default:
263 break;
264 }
265
266 wdt->wdd.min_timeout = MLXREG_WDT_MIN_TIMEOUT;
267 }
268
mlxreg_wdt_init_timeout(struct mlxreg_wdt * wdt,struct mlxreg_core_platform_data * pdata)269 static int mlxreg_wdt_init_timeout(struct mlxreg_wdt *wdt,
270 struct mlxreg_core_platform_data *pdata)
271 {
272 u32 timeout;
273
274 timeout = pdata->data[wdt->timeout_idx].health_cntr;
275 return mlxreg_wdt_set_timeout(&wdt->wdd, timeout);
276 }
277
mlxreg_wdt_probe(struct platform_device * pdev)278 static int mlxreg_wdt_probe(struct platform_device *pdev)
279 {
280 struct device *dev = &pdev->dev;
281 struct mlxreg_core_platform_data *pdata;
282 struct mlxreg_wdt *wdt;
283 int rc;
284
285 pdata = dev_get_platdata(dev);
286 if (!pdata) {
287 dev_err(dev, "Failed to get platform data.\n");
288 return -EINVAL;
289 }
290 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
291 if (!wdt)
292 return -ENOMEM;
293
294 wdt->wdd.parent = dev;
295 wdt->regmap = pdata->regmap;
296 rc = regmap_get_val_bytes(wdt->regmap);
297 if (rc < 0)
298 return -EINVAL;
299
300 wdt->regmap_val_sz = rc;
301 mlxreg_wdt_config(wdt, pdata);
302
303 if ((pdata->features & MLXREG_CORE_WD_FEATURE_NOWAYOUT))
304 watchdog_set_nowayout(&wdt->wdd, WATCHDOG_NOWAYOUT);
305 watchdog_stop_on_reboot(&wdt->wdd);
306 watchdog_stop_on_unregister(&wdt->wdd);
307 watchdog_set_drvdata(&wdt->wdd, wdt);
308 rc = mlxreg_wdt_init_timeout(wdt, pdata);
309 if (rc)
310 goto register_error;
311
312 if ((pdata->features & MLXREG_CORE_WD_FEATURE_START_AT_BOOT)) {
313 rc = mlxreg_wdt_start(&wdt->wdd);
314 if (rc)
315 goto register_error;
316 set_bit(WDOG_HW_RUNNING, &wdt->wdd.status);
317 }
318 mlxreg_wdt_check_card_reset(wdt);
319 rc = devm_watchdog_register_device(dev, &wdt->wdd);
320
321 register_error:
322 if (rc)
323 dev_err(dev, "Cannot register watchdog device (err=%d)\n", rc);
324 return rc;
325 }
326
327 static struct platform_driver mlxreg_wdt_driver = {
328 .probe = mlxreg_wdt_probe,
329 .driver = {
330 .name = "mlx-wdt",
331 },
332 };
333
334 module_platform_driver(mlxreg_wdt_driver);
335
336 MODULE_AUTHOR("Michael Shych <michaelsh@mellanox.com>");
337 MODULE_DESCRIPTION("Mellanox watchdog driver");
338 MODULE_LICENSE("GPL");
339 MODULE_ALIAS("platform:mlx-wdt");
340