1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Watchdog device driver for DA9062 and DA9061 PMICs
4 * Copyright (C) 2015 Dialog Semiconductor Ltd.
5 *
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/watchdog.h>
11 #include <linux/platform_device.h>
12 #include <linux/uaccess.h>
13 #include <linux/slab.h>
14 #include <linux/delay.h>
15 #include <linux/jiffies.h>
16 #include <linux/mfd/da9062/registers.h>
17 #include <linux/mfd/da9062/core.h>
18 #include <linux/regmap.h>
19 #include <linux/of.h>
20
21 static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
22 #define DA9062_TWDSCALE_DISABLE 0
23 #define DA9062_TWDSCALE_MIN 1
24 #define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
25 #define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN]
26 #define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX]
27 #define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1]
28 #define DA9062_RESET_PROTECTION_MS 300
29
30 struct da9062_watchdog {
31 struct da9062 *hw;
32 struct watchdog_device wdtdev;
33 };
34
da9062_wdt_timeout_to_sel(unsigned int secs)35 static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
36 {
37 unsigned int i;
38
39 for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
40 if (wdt_timeout[i] >= secs)
41 return i;
42 }
43
44 return DA9062_TWDSCALE_MAX;
45 }
46
da9062_reset_watchdog_timer(struct da9062_watchdog * wdt)47 static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
48 {
49 int ret;
50
51 ret = regmap_update_bits(wdt->hw->regmap,
52 DA9062AA_CONTROL_F,
53 DA9062AA_WATCHDOG_MASK,
54 DA9062AA_WATCHDOG_MASK);
55
56 return ret;
57 }
58
da9062_wdt_update_timeout_register(struct da9062_watchdog * wdt,unsigned int regval)59 static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
60 unsigned int regval)
61 {
62 struct da9062 *chip = wdt->hw;
63
64 regmap_update_bits(chip->regmap,
65 DA9062AA_CONTROL_D,
66 DA9062AA_TWDSCALE_MASK,
67 DA9062_TWDSCALE_DISABLE);
68
69 usleep_range(150, 300);
70
71 return regmap_update_bits(chip->regmap,
72 DA9062AA_CONTROL_D,
73 DA9062AA_TWDSCALE_MASK,
74 regval);
75 }
76
da9062_wdt_start(struct watchdog_device * wdd)77 static int da9062_wdt_start(struct watchdog_device *wdd)
78 {
79 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
80 unsigned int selector;
81 int ret;
82
83 selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
84 ret = da9062_wdt_update_timeout_register(wdt, selector);
85 if (ret)
86 dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
87 ret);
88
89 return ret;
90 }
91
da9062_wdt_stop(struct watchdog_device * wdd)92 static int da9062_wdt_stop(struct watchdog_device *wdd)
93 {
94 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
95 int ret;
96
97 ret = regmap_update_bits(wdt->hw->regmap,
98 DA9062AA_CONTROL_D,
99 DA9062AA_TWDSCALE_MASK,
100 DA9062_TWDSCALE_DISABLE);
101 if (ret)
102 dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
103 ret);
104
105 return ret;
106 }
107
da9062_wdt_ping(struct watchdog_device * wdd)108 static int da9062_wdt_ping(struct watchdog_device *wdd)
109 {
110 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
111 int ret;
112
113 ret = da9062_reset_watchdog_timer(wdt);
114 if (ret)
115 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
116 ret);
117
118 return ret;
119 }
120
da9062_wdt_set_timeout(struct watchdog_device * wdd,unsigned int timeout)121 static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
122 unsigned int timeout)
123 {
124 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
125 unsigned int selector;
126 int ret;
127
128 selector = da9062_wdt_timeout_to_sel(timeout);
129 ret = da9062_wdt_update_timeout_register(wdt, selector);
130 if (ret)
131 dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
132 ret);
133 else
134 wdd->timeout = wdt_timeout[selector];
135
136 return ret;
137 }
138
da9062_wdt_restart(struct watchdog_device * wdd,unsigned long action,void * data)139 static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
140 void *data)
141 {
142 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
143 int ret;
144
145 ret = regmap_write(wdt->hw->regmap,
146 DA9062AA_CONTROL_F,
147 DA9062AA_SHUTDOWN_MASK);
148 if (ret)
149 dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
150 ret);
151
152 /* wait for reset to assert... */
153 mdelay(500);
154
155 return ret;
156 }
157
158 static const struct watchdog_info da9062_watchdog_info = {
159 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
160 .identity = "DA9062 WDT",
161 };
162
163 static const struct watchdog_ops da9062_watchdog_ops = {
164 .owner = THIS_MODULE,
165 .start = da9062_wdt_start,
166 .stop = da9062_wdt_stop,
167 .ping = da9062_wdt_ping,
168 .set_timeout = da9062_wdt_set_timeout,
169 .restart = da9062_wdt_restart,
170 };
171
172 static const struct of_device_id da9062_compatible_id_table[] = {
173 { .compatible = "dlg,da9062-watchdog", },
174 { },
175 };
176
177 MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
178
da9062_wdt_probe(struct platform_device * pdev)179 static int da9062_wdt_probe(struct platform_device *pdev)
180 {
181 int ret;
182 struct da9062 *chip;
183 struct da9062_watchdog *wdt;
184
185 chip = dev_get_drvdata(pdev->dev.parent);
186 if (!chip)
187 return -EINVAL;
188
189 wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
190 if (!wdt)
191 return -ENOMEM;
192
193 wdt->hw = chip;
194
195 wdt->wdtdev.info = &da9062_watchdog_info;
196 wdt->wdtdev.ops = &da9062_watchdog_ops;
197 wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
198 wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
199 wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
200 wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
201 wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
202 wdt->wdtdev.parent = &pdev->dev;
203
204 watchdog_set_restart_priority(&wdt->wdtdev, 128);
205
206 watchdog_set_drvdata(&wdt->wdtdev, wdt);
207
208 ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev);
209 if (ret < 0) {
210 dev_err(wdt->hw->dev,
211 "watchdog registration failed (%d)\n", ret);
212 return ret;
213 }
214
215 return da9062_wdt_ping(&wdt->wdtdev);
216 }
217
218 static struct platform_driver da9062_wdt_driver = {
219 .probe = da9062_wdt_probe,
220 .driver = {
221 .name = "da9062-watchdog",
222 .of_match_table = da9062_compatible_id_table,
223 },
224 };
225 module_platform_driver(da9062_wdt_driver);
226
227 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
228 MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
229 MODULE_LICENSE("GPL");
230 MODULE_ALIAS("platform:da9062-watchdog");
231