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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/i2c.h>
15#include <linux/delay.h>
16#include <linux/jiffies.h>
17#include <linux/mfd/da9062/registers.h>
18#include <linux/mfd/da9062/core.h>
19#include <linux/property.h>
20#include <linux/regmap.h>
21#include <linux/of.h>
22
23static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
24#define DA9062_TWDSCALE_DISABLE 0
25#define DA9062_TWDSCALE_MIN 1
26#define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
27#define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN]
28#define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX]
29#define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1]
30#define DA9062_RESET_PROTECTION_MS 300
31
32struct da9062_watchdog {
33 struct da9062 *hw;
34 struct watchdog_device wdtdev;
35 bool use_sw_pm;
36};
37
38static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
39{
40 unsigned int i;
41
42 for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
43 if (wdt_timeout[i] >= secs)
44 return i;
45 }
46
47 return DA9062_TWDSCALE_MAX;
48}
49
50static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
51{
52 return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F,
53 DA9062AA_WATCHDOG_MASK,
54 DA9062AA_WATCHDOG_MASK);
55}
56
57static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
58 unsigned int regval)
59{
60 struct da9062 *chip = wdt->hw;
61 int ret;
62
63 ret = da9062_reset_watchdog_timer(wdt);
64 if (ret)
65 return ret;
66
67 regmap_update_bits(chip->regmap,
68 DA9062AA_CONTROL_D,
69 DA9062AA_TWDSCALE_MASK,
70 DA9062_TWDSCALE_DISABLE);
71
72 usleep_range(150, 300);
73
74 return regmap_update_bits(chip->regmap,
75 DA9062AA_CONTROL_D,
76 DA9062AA_TWDSCALE_MASK,
77 regval);
78}
79
80static int da9062_wdt_start(struct watchdog_device *wdd)
81{
82 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
83 unsigned int selector;
84 int ret;
85
86 selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
87 ret = da9062_wdt_update_timeout_register(wdt, selector);
88 if (ret)
89 dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
90 ret);
91
92 return ret;
93}
94
95static int da9062_wdt_stop(struct watchdog_device *wdd)
96{
97 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
98 int ret;
99
100 ret = regmap_update_bits(wdt->hw->regmap,
101 DA9062AA_CONTROL_D,
102 DA9062AA_TWDSCALE_MASK,
103 DA9062_TWDSCALE_DISABLE);
104 if (ret)
105 dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
106 ret);
107
108 return ret;
109}
110
111static int da9062_wdt_ping(struct watchdog_device *wdd)
112{
113 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
114 int ret;
115
116 ret = da9062_reset_watchdog_timer(wdt);
117 if (ret)
118 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
119 ret);
120
121 return ret;
122}
123
124static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
125 unsigned int timeout)
126{
127 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
128 unsigned int selector;
129 int ret;
130
131 selector = da9062_wdt_timeout_to_sel(timeout);
132 ret = da9062_wdt_update_timeout_register(wdt, selector);
133 if (ret)
134 dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
135 ret);
136 else
137 wdd->timeout = wdt_timeout[selector];
138
139 return ret;
140}
141
142static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
143 void *data)
144{
145 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
146 struct i2c_client *client = to_i2c_client(wdt->hw->dev);
147 int ret;
148
149
150 ret = i2c_smbus_write_byte_data(client, DA9062AA_CONTROL_F,
151 DA9062AA_SHUTDOWN_MASK);
152 if (ret < 0)
153 dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
154 ret);
155
156
157 mdelay(500);
158
159 return ret;
160}
161
162static const struct watchdog_info da9062_watchdog_info = {
163 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
164 .identity = "DA9062 WDT",
165};
166
167static const struct watchdog_ops da9062_watchdog_ops = {
168 .owner = THIS_MODULE,
169 .start = da9062_wdt_start,
170 .stop = da9062_wdt_stop,
171 .ping = da9062_wdt_ping,
172 .set_timeout = da9062_wdt_set_timeout,
173 .restart = da9062_wdt_restart,
174};
175
176static const struct of_device_id da9062_compatible_id_table[] = {
177 { .compatible = "dlg,da9062-watchdog", },
178 { },
179};
180
181MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
182
183static int da9062_wdt_probe(struct platform_device *pdev)
184{
185 struct device *dev = &pdev->dev;
186 int ret;
187 struct da9062 *chip;
188 struct da9062_watchdog *wdt;
189
190 chip = dev_get_drvdata(dev->parent);
191 if (!chip)
192 return -EINVAL;
193
194 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
195 if (!wdt)
196 return -ENOMEM;
197
198 wdt->use_sw_pm = device_property_present(dev, "dlg,use-sw-pm");
199
200 wdt->hw = chip;
201
202 wdt->wdtdev.info = &da9062_watchdog_info;
203 wdt->wdtdev.ops = &da9062_watchdog_ops;
204 wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
205 wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
206 wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
207 wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
208 wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
209 wdt->wdtdev.parent = dev;
210
211 watchdog_set_restart_priority(&wdt->wdtdev, 128);
212
213 watchdog_set_drvdata(&wdt->wdtdev, wdt);
214 dev_set_drvdata(dev, &wdt->wdtdev);
215
216 ret = devm_watchdog_register_device(dev, &wdt->wdtdev);
217 if (ret < 0)
218 return ret;
219
220 return da9062_wdt_ping(&wdt->wdtdev);
221}
222
223static int __maybe_unused da9062_wdt_suspend(struct device *dev)
224{
225 struct watchdog_device *wdd = dev_get_drvdata(dev);
226 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
227
228 if (!wdt->use_sw_pm)
229 return 0;
230
231 if (watchdog_active(wdd))
232 return da9062_wdt_stop(wdd);
233
234 return 0;
235}
236
237static int __maybe_unused da9062_wdt_resume(struct device *dev)
238{
239 struct watchdog_device *wdd = dev_get_drvdata(dev);
240 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
241
242 if (!wdt->use_sw_pm)
243 return 0;
244
245 if (watchdog_active(wdd))
246 return da9062_wdt_start(wdd);
247
248 return 0;
249}
250
251static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops,
252 da9062_wdt_suspend, da9062_wdt_resume);
253
254static struct platform_driver da9062_wdt_driver = {
255 .probe = da9062_wdt_probe,
256 .driver = {
257 .name = "da9062-watchdog",
258 .pm = &da9062_wdt_pm_ops,
259 .of_match_table = da9062_compatible_id_table,
260 },
261};
262module_platform_driver(da9062_wdt_driver);
263
264MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
265MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
266MODULE_LICENSE("GPL");
267MODULE_ALIAS("platform:da9062-watchdog");
268
