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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 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
59static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
60 unsigned int regval)
61{
62 struct da9062 *chip = wdt->hw;
63 int ret;
64
65 ret = da9062_reset_watchdog_timer(wdt);
66 if (ret)
67 return ret;
68
69 regmap_update_bits(chip->regmap,
70 DA9062AA_CONTROL_D,
71 DA9062AA_TWDSCALE_MASK,
72 DA9062_TWDSCALE_DISABLE);
73
74 usleep_range(150, 300);
75
76 return regmap_update_bits(chip->regmap,
77 DA9062AA_CONTROL_D,
78 DA9062AA_TWDSCALE_MASK,
79 regval);
80}
81
82static int da9062_wdt_start(struct watchdog_device *wdd)
83{
84 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
85 unsigned int selector;
86 int ret;
87
88 selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
89 ret = da9062_wdt_update_timeout_register(wdt, selector);
90 if (ret)
91 dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
92 ret);
93
94 return ret;
95}
96
97static int da9062_wdt_stop(struct watchdog_device *wdd)
98{
99 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
100 int ret;
101
102 ret = da9062_reset_watchdog_timer(wdt);
103 if (ret) {
104 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
105 ret);
106 return ret;
107 }
108
109 ret = regmap_update_bits(wdt->hw->regmap,
110 DA9062AA_CONTROL_D,
111 DA9062AA_TWDSCALE_MASK,
112 DA9062_TWDSCALE_DISABLE);
113 if (ret)
114 dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
115 ret);
116
117 return ret;
118}
119
120static int da9062_wdt_ping(struct watchdog_device *wdd)
121{
122 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
123 int ret;
124
125 ret = da9062_reset_watchdog_timer(wdt);
126 if (ret)
127 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
128 ret);
129
130 return ret;
131}
132
133static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
134 unsigned int timeout)
135{
136 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
137 unsigned int selector;
138 int ret;
139
140 selector = da9062_wdt_timeout_to_sel(timeout);
141 ret = da9062_wdt_update_timeout_register(wdt, selector);
142 if (ret)
143 dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
144 ret);
145 else
146 wdd->timeout = wdt_timeout[selector];
147
148 return ret;
149}
150
151static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
152 void *data)
153{
154 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
155 int ret;
156
157 ret = regmap_write(wdt->hw->regmap,
158 DA9062AA_CONTROL_F,
159 DA9062AA_SHUTDOWN_MASK);
160 if (ret)
161 dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
162 ret);
163
164
165 mdelay(500);
166
167 return ret;
168}
169
170static const struct watchdog_info da9062_watchdog_info = {
171 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
172 .identity = "DA9062 WDT",
173};
174
175static const struct watchdog_ops da9062_watchdog_ops = {
176 .owner = THIS_MODULE,
177 .start = da9062_wdt_start,
178 .stop = da9062_wdt_stop,
179 .ping = da9062_wdt_ping,
180 .set_timeout = da9062_wdt_set_timeout,
181 .restart = da9062_wdt_restart,
182};
183
184static const struct of_device_id da9062_compatible_id_table[] = {
185 { .compatible = "dlg,da9062-watchdog", },
186 { },
187};
188
189MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
190
191static int da9062_wdt_probe(struct platform_device *pdev)
192{
193 int ret;
194 struct da9062 *chip;
195 struct da9062_watchdog *wdt;
196
197 chip = dev_get_drvdata(pdev->dev.parent);
198 if (!chip)
199 return -EINVAL;
200
201 wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
202 if (!wdt)
203 return -ENOMEM;
204
205 wdt->hw = chip;
206
207 wdt->wdtdev.info = &da9062_watchdog_info;
208 wdt->wdtdev.ops = &da9062_watchdog_ops;
209 wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
210 wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
211 wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
212 wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
213 wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
214 wdt->wdtdev.parent = &pdev->dev;
215
216 watchdog_set_restart_priority(&wdt->wdtdev, 128);
217
218 watchdog_set_drvdata(&wdt->wdtdev, wdt);
219
220 ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev);
221 if (ret < 0) {
222 dev_err(wdt->hw->dev,
223 "watchdog registration failed (%d)\n", ret);
224 return ret;
225 }
226
227 return da9062_wdt_ping(&wdt->wdtdev);
228}
229
230static struct platform_driver da9062_wdt_driver = {
231 .probe = da9062_wdt_probe,
232 .driver = {
233 .name = "da9062-watchdog",
234 .of_match_table = da9062_compatible_id_table,
235 },
236};
237module_platform_driver(da9062_wdt_driver);
238
239MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
240MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
241MODULE_LICENSE("GPL");
242MODULE_ALIAS("platform:da9062-watchdog");
243
