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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_read_timeout(struct da9062_watchdog *wdt)
39{
40 unsigned int val;
41
42 regmap_read(wdt->hw->regmap, DA9062AA_CONTROL_D, &val);
43
44 return wdt_timeout[val & DA9062AA_TWDSCALE_MASK];
45}
46
47static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
48{
49 unsigned int i;
50
51 for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
52 if (wdt_timeout[i] >= secs)
53 return i;
54 }
55
56 return DA9062_TWDSCALE_MAX;
57}
58
59static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
60{
61 return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F,
62 DA9062AA_WATCHDOG_MASK,
63 DA9062AA_WATCHDOG_MASK);
64}
65
66static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
67 unsigned int regval)
68{
69 struct da9062 *chip = wdt->hw;
70
71 regmap_update_bits(chip->regmap,
72 DA9062AA_CONTROL_D,
73 DA9062AA_TWDSCALE_MASK,
74 DA9062_TWDSCALE_DISABLE);
75
76 usleep_range(150, 300);
77
78 return regmap_update_bits(chip->regmap,
79 DA9062AA_CONTROL_D,
80 DA9062AA_TWDSCALE_MASK,
81 regval);
82}
83
84static int da9062_wdt_start(struct watchdog_device *wdd)
85{
86 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
87 unsigned int selector;
88 int ret;
89
90 selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
91 ret = da9062_wdt_update_timeout_register(wdt, selector);
92 if (ret)
93 dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
94 ret);
95
96 return ret;
97}
98
99static int da9062_wdt_stop(struct watchdog_device *wdd)
100{
101 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
102 int ret;
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
121
122
123
124 if (system_state > SYSTEM_RUNNING)
125 return 0;
126
127 ret = da9062_reset_watchdog_timer(wdt);
128 if (ret)
129 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
130 ret);
131
132 return ret;
133}
134
135static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
136 unsigned int timeout)
137{
138 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
139 unsigned int selector;
140 int ret;
141
142 selector = da9062_wdt_timeout_to_sel(timeout);
143 ret = da9062_wdt_update_timeout_register(wdt, selector);
144 if (ret)
145 dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
146 ret);
147 else
148 wdd->timeout = wdt_timeout[selector];
149
150 return ret;
151}
152
153static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
154 void *data)
155{
156 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
157 struct i2c_client *client = to_i2c_client(wdt->hw->dev);
158 int ret;
159
160
161 ret = i2c_smbus_write_byte_data(client, DA9062AA_CONTROL_F,
162 DA9062AA_SHUTDOWN_MASK);
163 if (ret < 0)
164 dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
165 ret);
166
167
168 mdelay(500);
169
170 return ret;
171}
172
173static const struct watchdog_info da9062_watchdog_info = {
174 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
175 .identity = "DA9062 WDT",
176};
177
178static const struct watchdog_ops da9062_watchdog_ops = {
179 .owner = THIS_MODULE,
180 .start = da9062_wdt_start,
181 .stop = da9062_wdt_stop,
182 .ping = da9062_wdt_ping,
183 .set_timeout = da9062_wdt_set_timeout,
184 .restart = da9062_wdt_restart,
185};
186
187static const struct of_device_id da9062_compatible_id_table[] = {
188 { .compatible = "dlg,da9062-watchdog", },
189 { },
190};
191
192MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
193
194static int da9062_wdt_probe(struct platform_device *pdev)
195{
196 struct device *dev = &pdev->dev;
197 unsigned int timeout;
198 struct da9062 *chip;
199 struct da9062_watchdog *wdt;
200
201 chip = dev_get_drvdata(dev->parent);
202 if (!chip)
203 return -EINVAL;
204
205 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
206 if (!wdt)
207 return -ENOMEM;
208
209 wdt->use_sw_pm = device_property_present(dev, "dlg,use-sw-pm");
210
211 wdt->hw = chip;
212
213 wdt->wdtdev.info = &da9062_watchdog_info;
214 wdt->wdtdev.ops = &da9062_watchdog_ops;
215 wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
216 wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
217 wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
218 wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
219 wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
220 wdt->wdtdev.parent = dev;
221
222 watchdog_set_restart_priority(&wdt->wdtdev, 128);
223
224 watchdog_set_drvdata(&wdt->wdtdev, wdt);
225 dev_set_drvdata(dev, &wdt->wdtdev);
226
227 timeout = da9062_wdt_read_timeout(wdt);
228 if (timeout)
229 wdt->wdtdev.timeout = timeout;
230
231
232 watchdog_init_timeout(&wdt->wdtdev, 0, dev);
233
234 if (timeout) {
235 da9062_wdt_set_timeout(&wdt->wdtdev, wdt->wdtdev.timeout);
236 set_bit(WDOG_HW_RUNNING, &wdt->wdtdev.status);
237 }
238
239 return devm_watchdog_register_device(dev, &wdt->wdtdev);
240}
241
242static int __maybe_unused da9062_wdt_suspend(struct device *dev)
243{
244 struct watchdog_device *wdd = dev_get_drvdata(dev);
245 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
246
247 if (!wdt->use_sw_pm)
248 return 0;
249
250 if (watchdog_active(wdd))
251 return da9062_wdt_stop(wdd);
252
253 return 0;
254}
255
256static int __maybe_unused da9062_wdt_resume(struct device *dev)
257{
258 struct watchdog_device *wdd = dev_get_drvdata(dev);
259 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
260
261 if (!wdt->use_sw_pm)
262 return 0;
263
264 if (watchdog_active(wdd))
265 return da9062_wdt_start(wdd);
266
267 return 0;
268}
269
270static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops,
271 da9062_wdt_suspend, da9062_wdt_resume);
272
273static struct platform_driver da9062_wdt_driver = {
274 .probe = da9062_wdt_probe,
275 .driver = {
276 .name = "da9062-watchdog",
277 .pm = &da9062_wdt_pm_ops,
278 .of_match_table = da9062_compatible_id_table,
279 },
280};
281module_platform_driver(da9062_wdt_driver);
282
283MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
284MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
285MODULE_LICENSE("GPL");
286MODULE_ALIAS("platform:da9062-watchdog");
287
