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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
21static 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
30struct da9062_watchdog {
31 struct da9062 *hw;
32 struct watchdog_device wdtdev;
33};
34
35static 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
47static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
48{
49 return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F,
50 DA9062AA_WATCHDOG_MASK,
51 DA9062AA_WATCHDOG_MASK);
52}
53
54static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
55 unsigned int regval)
56{
57 struct da9062 *chip = wdt->hw;
58 int ret;
59
60 ret = da9062_reset_watchdog_timer(wdt);
61 if (ret)
62 return ret;
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
77static 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
92static int da9062_wdt_stop(struct watchdog_device *wdd)
93{
94 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
95 int ret;
96
97 ret = da9062_reset_watchdog_timer(wdt);
98 if (ret) {
99 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
100 ret);
101 return ret;
102 }
103
104 ret = regmap_update_bits(wdt->hw->regmap,
105 DA9062AA_CONTROL_D,
106 DA9062AA_TWDSCALE_MASK,
107 DA9062_TWDSCALE_DISABLE);
108 if (ret)
109 dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
110 ret);
111
112 return ret;
113}
114
115static int da9062_wdt_ping(struct watchdog_device *wdd)
116{
117 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
118 int ret;
119
120 ret = da9062_reset_watchdog_timer(wdt);
121 if (ret)
122 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
123 ret);
124
125 return ret;
126}
127
128static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
129 unsigned int timeout)
130{
131 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
132 unsigned int selector;
133 int ret;
134
135 selector = da9062_wdt_timeout_to_sel(timeout);
136 ret = da9062_wdt_update_timeout_register(wdt, selector);
137 if (ret)
138 dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
139 ret);
140 else
141 wdd->timeout = wdt_timeout[selector];
142
143 return ret;
144}
145
146static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
147 void *data)
148{
149 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
150 int ret;
151
152 ret = regmap_write(wdt->hw->regmap,
153 DA9062AA_CONTROL_F,
154 DA9062AA_SHUTDOWN_MASK);
155 if (ret)
156 dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
157 ret);
158
159
160 mdelay(500);
161
162 return ret;
163}
164
165static const struct watchdog_info da9062_watchdog_info = {
166 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
167 .identity = "DA9062 WDT",
168};
169
170static const struct watchdog_ops da9062_watchdog_ops = {
171 .owner = THIS_MODULE,
172 .start = da9062_wdt_start,
173 .stop = da9062_wdt_stop,
174 .ping = da9062_wdt_ping,
175 .set_timeout = da9062_wdt_set_timeout,
176 .restart = da9062_wdt_restart,
177};
178
179static const struct of_device_id da9062_compatible_id_table[] = {
180 { .compatible = "dlg,da9062-watchdog", },
181 { },
182};
183
184MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
185
186static int da9062_wdt_probe(struct platform_device *pdev)
187{
188 struct device *dev = &pdev->dev;
189 int ret;
190 struct da9062 *chip;
191 struct da9062_watchdog *wdt;
192
193 chip = dev_get_drvdata(dev->parent);
194 if (!chip)
195 return -EINVAL;
196
197 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
198 if (!wdt)
199 return -ENOMEM;
200
201 wdt->hw = chip;
202
203 wdt->wdtdev.info = &da9062_watchdog_info;
204 wdt->wdtdev.ops = &da9062_watchdog_ops;
205 wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
206 wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
207 wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
208 wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
209 wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
210 wdt->wdtdev.parent = dev;
211
212 watchdog_set_restart_priority(&wdt->wdtdev, 128);
213
214 watchdog_set_drvdata(&wdt->wdtdev, wdt);
215
216 ret = devm_watchdog_register_device(dev, &wdt->wdtdev);
217 if (ret < 0) {
218 dev_err(wdt->hw->dev,
219 "watchdog registration failed (%d)\n", ret);
220 return ret;
221 }
222
223 return da9062_wdt_ping(&wdt->wdtdev);
224}
225
226static struct platform_driver da9062_wdt_driver = {
227 .probe = da9062_wdt_probe,
228 .driver = {
229 .name = "da9062-watchdog",
230 .of_match_table = da9062_compatible_id_table,
231 },
232};
233module_platform_driver(da9062_wdt_driver);
234
235MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
236MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
237MODULE_LICENSE("GPL");
238MODULE_ALIAS("platform:da9062-watchdog");
239
