1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * System monitoring driver for DA9052 PMICs.
4 *
5 * Copyright(c) 2012 Dialog Semiconductor Ltd.
6 *
7 * Author: Anthony Olech <Anthony.Olech@diasemi.com>
8 *
9 */
10
11 #include <linux/module.h>
12 #include <linux/delay.h>
13 #include <linux/uaccess.h>
14 #include <linux/platform_device.h>
15 #include <linux/time.h>
16 #include <linux/watchdog.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/jiffies.h>
20
21 #include <linux/mfd/da9052/reg.h>
22 #include <linux/mfd/da9052/da9052.h>
23
24 #define DA9052_DEF_TIMEOUT 4
25 #define DA9052_TWDMIN 256
26
27 struct da9052_wdt_data {
28 struct watchdog_device wdt;
29 struct da9052 *da9052;
30 unsigned long jpast;
31 };
32
33 static bool nowayout = WATCHDOG_NOWAYOUT;
34 module_param(nowayout, bool, 0);
35 MODULE_PARM_DESC(nowayout,
36 "Watchdog cannot be stopped once started (default="
37 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
38
39 static int timeout;
40 module_param(timeout, int, 0);
41 MODULE_PARM_DESC(timeout,
42 "Watchdog timeout in seconds. (default = "
43 __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
44
45 static const struct {
46 u8 reg_val;
47 int time; /* Seconds */
48 } da9052_wdt_maps[] = {
49 { 1, 2 },
50 { 2, 4 },
51 { 3, 8 },
52 { 4, 16 },
53 { 5, 32 },
54 { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */
55 { 6, 65 },
56 { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */
57 { 7, 131 },
58 };
59
60
da9052_wdt_set_timeout(struct watchdog_device * wdt_dev,unsigned int timeout)61 static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev,
62 unsigned int timeout)
63 {
64 struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
65 struct da9052 *da9052 = driver_data->da9052;
66 int ret, i;
67
68 /*
69 * Disable the Watchdog timer before setting
70 * new time out.
71 */
72 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
73 DA9052_CONTROLD_TWDSCALE, 0);
74 if (ret < 0) {
75 dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n",
76 ret);
77 return ret;
78 }
79 if (timeout) {
80 /*
81 * To change the timeout, da9052 needs to
82 * be disabled for at least 150 us.
83 */
84 udelay(150);
85
86 /* Set the desired timeout */
87 for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++)
88 if (da9052_wdt_maps[i].time == timeout)
89 break;
90
91 if (i == ARRAY_SIZE(da9052_wdt_maps))
92 ret = -EINVAL;
93 else
94 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
95 DA9052_CONTROLD_TWDSCALE,
96 da9052_wdt_maps[i].reg_val);
97 if (ret < 0) {
98 dev_err(da9052->dev,
99 "Failed to update timescale bit, %d\n", ret);
100 return ret;
101 }
102
103 wdt_dev->timeout = timeout;
104 driver_data->jpast = jiffies;
105 }
106
107 return 0;
108 }
109
da9052_wdt_start(struct watchdog_device * wdt_dev)110 static int da9052_wdt_start(struct watchdog_device *wdt_dev)
111 {
112 return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
113 }
114
da9052_wdt_stop(struct watchdog_device * wdt_dev)115 static int da9052_wdt_stop(struct watchdog_device *wdt_dev)
116 {
117 return da9052_wdt_set_timeout(wdt_dev, 0);
118 }
119
da9052_wdt_ping(struct watchdog_device * wdt_dev)120 static int da9052_wdt_ping(struct watchdog_device *wdt_dev)
121 {
122 struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
123 struct da9052 *da9052 = driver_data->da9052;
124 unsigned long msec, jnow = jiffies;
125 int ret;
126
127 /*
128 * We have a minimum time for watchdog window called TWDMIN. A write
129 * to the watchdog before this elapsed time should cause an error.
130 */
131 msec = (jnow - driver_data->jpast) * 1000/HZ;
132 if (msec < DA9052_TWDMIN)
133 mdelay(msec);
134
135 /* Reset the watchdog timer */
136 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
137 DA9052_CONTROLD_WATCHDOG, 1 << 7);
138 if (ret < 0)
139 return ret;
140
141 /*
142 * FIXME: Reset the watchdog core, in general PMIC
143 * is supposed to do this
144 */
145 return da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
146 DA9052_CONTROLD_WATCHDOG, 0 << 7);
147 }
148
149 static const struct watchdog_info da9052_wdt_info = {
150 .options = WDIOF_SETTIMEOUT |
151 WDIOF_KEEPALIVEPING |
152 WDIOF_CARDRESET |
153 WDIOF_OVERHEAT |
154 WDIOF_POWERUNDER,
155 .identity = "DA9052 Watchdog",
156 };
157
158 static const struct watchdog_ops da9052_wdt_ops = {
159 .owner = THIS_MODULE,
160 .start = da9052_wdt_start,
161 .stop = da9052_wdt_stop,
162 .ping = da9052_wdt_ping,
163 .set_timeout = da9052_wdt_set_timeout,
164 };
165
166
da9052_wdt_probe(struct platform_device * pdev)167 static int da9052_wdt_probe(struct platform_device *pdev)
168 {
169 struct device *dev = &pdev->dev;
170 struct da9052 *da9052 = dev_get_drvdata(dev->parent);
171 struct da9052_wdt_data *driver_data;
172 struct watchdog_device *da9052_wdt;
173 int ret;
174
175 driver_data = devm_kzalloc(dev, sizeof(*driver_data), GFP_KERNEL);
176 if (!driver_data)
177 return -ENOMEM;
178 driver_data->da9052 = da9052;
179
180 da9052_wdt = &driver_data->wdt;
181
182 da9052_wdt->timeout = DA9052_DEF_TIMEOUT;
183 da9052_wdt->min_hw_heartbeat_ms = DA9052_TWDMIN;
184 da9052_wdt->info = &da9052_wdt_info;
185 da9052_wdt->ops = &da9052_wdt_ops;
186 da9052_wdt->parent = dev;
187 watchdog_set_drvdata(da9052_wdt, driver_data);
188 watchdog_init_timeout(da9052_wdt, timeout, dev);
189 watchdog_set_nowayout(da9052_wdt, nowayout);
190
191 if (da9052->fault_log & DA9052_FAULTLOG_TWDERROR)
192 da9052_wdt->bootstatus |= WDIOF_CARDRESET;
193 if (da9052->fault_log & DA9052_FAULTLOG_TEMPOVER)
194 da9052_wdt->bootstatus |= WDIOF_OVERHEAT;
195 if (da9052->fault_log & DA9052_FAULTLOG_VDDFAULT)
196 da9052_wdt->bootstatus |= WDIOF_POWERUNDER;
197
198 ret = da9052_reg_read(da9052, DA9052_CONTROL_D_REG);
199 if (ret < 0)
200 return ret;
201
202 /* Check if FW enabled the watchdog */
203 if (ret & DA9052_CONTROLD_TWDSCALE) {
204 /* Ensure proper initialization */
205 da9052_wdt_start(da9052_wdt);
206 set_bit(WDOG_HW_RUNNING, &da9052_wdt->status);
207 }
208
209 return devm_watchdog_register_device(dev, &driver_data->wdt);
210 }
211
212 static struct platform_driver da9052_wdt_driver = {
213 .probe = da9052_wdt_probe,
214 .driver = {
215 .name = "da9052-watchdog",
216 },
217 };
218
219 module_platform_driver(da9052_wdt_driver);
220
221 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
222 MODULE_DESCRIPTION("DA9052 SM Device Driver");
223 MODULE_LICENSE("GPL");
224 MODULE_ALIAS("platform:da9052-watchdog");
225