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 * @device: basic device;
34 * @pdata: data received from platform driver;
35 * @regmap: register map of parent device;
36 * @timeout: defined timeout in sec.;
37 * @action_idx: index for direct access to action register;
38 * @timeout_idx:index for direct access to TO register;
39 * @tleft_idx: index for direct access to time left register;
40 * @ping_idx: index for direct access to ping register;
41 * @reset_idx: index for direct access to reset cause register;
42 * @wd_type: watchdog HW type;
43 */
44 struct mlxreg_wdt {
45 struct watchdog_device wdd;
46 struct mlxreg_core_platform_data *pdata;
47 void *regmap;
48 int action_idx;
49 int timeout_idx;
50 int tleft_idx;
51 int ping_idx;
52 int reset_idx;
53 int regmap_val_sz;
54 enum mlxreg_wdt_type wdt_type;
55 };
56
mlxreg_wdt_check_card_reset(struct mlxreg_wdt * wdt)57 static void mlxreg_wdt_check_card_reset(struct mlxreg_wdt *wdt)
58 {
59 struct mlxreg_core_data *reg_data;
60 u32 regval;
61 int rc;
62
63 if (wdt->reset_idx == -EINVAL)
64 return;
65
66 if (!(wdt->wdd.info->options & WDIOF_CARDRESET))
67 return;
68
69 reg_data = &wdt->pdata->data[wdt->reset_idx];
70 rc = regmap_read(wdt->regmap, reg_data->reg, ®val);
71 if (!rc) {
72 if (regval & ~reg_data->mask) {
73 wdt->wdd.bootstatus = WDIOF_CARDRESET;
74 dev_info(wdt->wdd.parent,
75 "watchdog previously reset the CPU\n");
76 }
77 }
78 }
79
mlxreg_wdt_start(struct watchdog_device * wdd)80 static int mlxreg_wdt_start(struct watchdog_device *wdd)
81 {
82 struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
83 struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->action_idx];
84
85 return regmap_update_bits(wdt->regmap, reg_data->reg, ~reg_data->mask,
86 BIT(reg_data->bit));
87 }
88
mlxreg_wdt_stop(struct watchdog_device * wdd)89 static int mlxreg_wdt_stop(struct watchdog_device *wdd)
90 {
91 struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
92 struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->action_idx];
93
94 return regmap_update_bits(wdt->regmap, reg_data->reg, ~reg_data->mask,
95 ~BIT(reg_data->bit));
96 }
97
mlxreg_wdt_ping(struct watchdog_device * wdd)98 static int mlxreg_wdt_ping(struct watchdog_device *wdd)
99 {
100 struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
101 struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->ping_idx];
102
103 return regmap_update_bits_base(wdt->regmap, reg_data->reg,
104 ~reg_data->mask, BIT(reg_data->bit),
105 NULL, false, true);
106 }
107
mlxreg_wdt_set_timeout(struct watchdog_device * wdd,unsigned int timeout)108 static int mlxreg_wdt_set_timeout(struct watchdog_device *wdd,
109 unsigned int timeout)
110 {
111 struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
112 struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->timeout_idx];
113 u32 regval, set_time, hw_timeout;
114 int rc;
115
116 switch (wdt->wdt_type) {
117 case MLX_WDT_TYPE1:
118 rc = regmap_read(wdt->regmap, reg_data->reg, ®val);
119 if (rc)
120 return rc;
121
122 hw_timeout = order_base_2(timeout * MLXREG_WDT_CLOCK_SCALE);
123 regval = (regval & reg_data->mask) | hw_timeout;
124 /* Rowndown to actual closest number of sec. */
125 set_time = BIT(hw_timeout) / MLXREG_WDT_CLOCK_SCALE;
126 rc = regmap_write(wdt->regmap, reg_data->reg, regval);
127 break;
128 case MLX_WDT_TYPE2:
129 set_time = timeout;
130 rc = regmap_write(wdt->regmap, reg_data->reg, timeout);
131 break;
132 case MLX_WDT_TYPE3:
133 /* WD_TYPE3 has 2B set time register */
134 set_time = timeout;
135 if (wdt->regmap_val_sz == 1) {
136 regval = timeout & 0xff;
137 rc = regmap_write(wdt->regmap, reg_data->reg, regval);
138 if (!rc) {
139 regval = (timeout & 0xff00) >> 8;
140 rc = regmap_write(wdt->regmap,
141 reg_data->reg + 1, regval);
142 }
143 } else {
144 rc = regmap_write(wdt->regmap, reg_data->reg, timeout);
145 }
146 break;
147 default:
148 return -EINVAL;
149 }
150
151 wdd->timeout = set_time;
152 if (!rc) {
153 /*
154 * Restart watchdog with new timeout period
155 * if watchdog is already started.
156 */
157 if (watchdog_active(wdd)) {
158 rc = mlxreg_wdt_stop(wdd);
159 if (!rc)
160 rc = mlxreg_wdt_start(wdd);
161 }
162 }
163
164 return rc;
165 }
166
mlxreg_wdt_get_timeleft(struct watchdog_device * wdd)167 static unsigned int mlxreg_wdt_get_timeleft(struct watchdog_device *wdd)
168 {
169 struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
170 struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->tleft_idx];
171 u32 regval, msb, lsb;
172 int rc;
173
174 if (wdt->wdt_type == MLX_WDT_TYPE2) {
175 rc = regmap_read(wdt->regmap, reg_data->reg, ®val);
176 } else {
177 /* WD_TYPE3 has 2 byte timeleft register */
178 if (wdt->regmap_val_sz == 1) {
179 rc = regmap_read(wdt->regmap, reg_data->reg, &lsb);
180 if (!rc) {
181 rc = regmap_read(wdt->regmap,
182 reg_data->reg + 1, &msb);
183 regval = (msb & 0xff) << 8 | (lsb & 0xff);
184 }
185 } else {
186 rc = regmap_read(wdt->regmap, reg_data->reg, ®val);
187 }
188 }
189
190 /* Return 0 timeleft in case of failure register read. */
191 return rc == 0 ? regval : 0;
192 }
193
194 static const struct watchdog_ops mlxreg_wdt_ops_type1 = {
195 .start = mlxreg_wdt_start,
196 .stop = mlxreg_wdt_stop,
197 .ping = mlxreg_wdt_ping,
198 .set_timeout = mlxreg_wdt_set_timeout,
199 .owner = THIS_MODULE,
200 };
201
202 static const struct watchdog_ops mlxreg_wdt_ops_type2 = {
203 .start = mlxreg_wdt_start,
204 .stop = mlxreg_wdt_stop,
205 .ping = mlxreg_wdt_ping,
206 .set_timeout = mlxreg_wdt_set_timeout,
207 .get_timeleft = mlxreg_wdt_get_timeleft,
208 .owner = THIS_MODULE,
209 };
210
211 static const struct watchdog_info mlxreg_wdt_main_info = {
212 .options = MLXREG_WDT_OPTIONS_BASE
213 | WDIOF_CARDRESET,
214 .identity = "mlx-wdt-main",
215 };
216
217 static const struct watchdog_info mlxreg_wdt_aux_info = {
218 .options = MLXREG_WDT_OPTIONS_BASE
219 | WDIOF_ALARMONLY,
220 .identity = "mlx-wdt-aux",
221 };
222
mlxreg_wdt_config(struct mlxreg_wdt * wdt,struct mlxreg_core_platform_data * pdata)223 static void mlxreg_wdt_config(struct mlxreg_wdt *wdt,
224 struct mlxreg_core_platform_data *pdata)
225 {
226 struct mlxreg_core_data *data = pdata->data;
227 int i;
228
229 wdt->reset_idx = -EINVAL;
230 for (i = 0; i < pdata->counter; i++, data++) {
231 if (strnstr(data->label, "action", sizeof(data->label)))
232 wdt->action_idx = i;
233 else if (strnstr(data->label, "timeout", sizeof(data->label)))
234 wdt->timeout_idx = i;
235 else if (strnstr(data->label, "timeleft", sizeof(data->label)))
236 wdt->tleft_idx = i;
237 else if (strnstr(data->label, "ping", sizeof(data->label)))
238 wdt->ping_idx = i;
239 else if (strnstr(data->label, "reset", sizeof(data->label)))
240 wdt->reset_idx = i;
241 }
242
243 wdt->pdata = pdata;
244 if (strnstr(pdata->identity, mlxreg_wdt_main_info.identity,
245 sizeof(mlxreg_wdt_main_info.identity)))
246 wdt->wdd.info = &mlxreg_wdt_main_info;
247 else
248 wdt->wdd.info = &mlxreg_wdt_aux_info;
249
250 wdt->wdt_type = pdata->version;
251 switch (wdt->wdt_type) {
252 case MLX_WDT_TYPE1:
253 wdt->wdd.ops = &mlxreg_wdt_ops_type1;
254 wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE1;
255 break;
256 case MLX_WDT_TYPE2:
257 wdt->wdd.ops = &mlxreg_wdt_ops_type2;
258 wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE2;
259 break;
260 case MLX_WDT_TYPE3:
261 wdt->wdd.ops = &mlxreg_wdt_ops_type2;
262 wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE3;
263 break;
264 default:
265 break;
266 }
267
268 wdt->wdd.min_timeout = MLXREG_WDT_MIN_TIMEOUT;
269 }
270
mlxreg_wdt_init_timeout(struct mlxreg_wdt * wdt,struct mlxreg_core_platform_data * pdata)271 static int mlxreg_wdt_init_timeout(struct mlxreg_wdt *wdt,
272 struct mlxreg_core_platform_data *pdata)
273 {
274 u32 timeout;
275
276 timeout = pdata->data[wdt->timeout_idx].health_cntr;
277 return mlxreg_wdt_set_timeout(&wdt->wdd, timeout);
278 }
279
mlxreg_wdt_probe(struct platform_device * pdev)280 static int mlxreg_wdt_probe(struct platform_device *pdev)
281 {
282 struct device *dev = &pdev->dev;
283 struct mlxreg_core_platform_data *pdata;
284 struct mlxreg_wdt *wdt;
285 int rc;
286
287 pdata = dev_get_platdata(dev);
288 if (!pdata) {
289 dev_err(dev, "Failed to get platform data.\n");
290 return -EINVAL;
291 }
292 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
293 if (!wdt)
294 return -ENOMEM;
295
296 wdt->wdd.parent = dev;
297 wdt->regmap = pdata->regmap;
298 rc = regmap_get_val_bytes(wdt->regmap);
299 if (rc < 0)
300 return -EINVAL;
301
302 wdt->regmap_val_sz = rc;
303 mlxreg_wdt_config(wdt, pdata);
304
305 if ((pdata->features & MLXREG_CORE_WD_FEATURE_NOWAYOUT))
306 watchdog_set_nowayout(&wdt->wdd, WATCHDOG_NOWAYOUT);
307 watchdog_stop_on_reboot(&wdt->wdd);
308 watchdog_stop_on_unregister(&wdt->wdd);
309 watchdog_set_drvdata(&wdt->wdd, wdt);
310 rc = mlxreg_wdt_init_timeout(wdt, pdata);
311 if (rc)
312 goto register_error;
313
314 if ((pdata->features & MLXREG_CORE_WD_FEATURE_START_AT_BOOT)) {
315 rc = mlxreg_wdt_start(&wdt->wdd);
316 if (rc)
317 goto register_error;
318 set_bit(WDOG_HW_RUNNING, &wdt->wdd.status);
319 }
320 mlxreg_wdt_check_card_reset(wdt);
321 rc = devm_watchdog_register_device(dev, &wdt->wdd);
322
323 register_error:
324 if (rc)
325 dev_err(dev, "Cannot register watchdog device (err=%d)\n", rc);
326 return rc;
327 }
328
329 static struct platform_driver mlxreg_wdt_driver = {
330 .probe = mlxreg_wdt_probe,
331 .driver = {
332 .name = "mlx-wdt",
333 },
334 };
335
336 module_platform_driver(mlxreg_wdt_driver);
337
338 MODULE_AUTHOR("Michael Shych <michaelsh@mellanox.com>");
339 MODULE_DESCRIPTION("Mellanox watchdog driver");
340 MODULE_LICENSE("GPL");
341 MODULE_ALIAS("platform:mlx-wdt");
342