Merge tag 'mips_5.14_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux
[linux-2.6-microblaze.git] / drivers / watchdog / da9062_wdt.c
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/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
23 static 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
32 struct da9062_watchdog {
33         struct da9062 *hw;
34         struct watchdog_device wdtdev;
35         bool use_sw_pm;
36 };
37
38 static 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
47 static 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
59 static 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
66 static 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
84 static 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
99 static 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
115 static 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
128 static 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
146 static 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         struct i2c_client *client = to_i2c_client(wdt->hw->dev);
151         int ret;
152
153         /* Don't use regmap because it is not atomic safe */
154         ret = i2c_smbus_write_byte_data(client, DA9062AA_CONTROL_F,
155                                         DA9062AA_SHUTDOWN_MASK);
156         if (ret < 0)
157                 dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
158                           ret);
159
160         /* wait for reset to assert... */
161         mdelay(500);
162
163         return ret;
164 }
165
166 static const struct watchdog_info da9062_watchdog_info = {
167         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
168         .identity = "DA9062 WDT",
169 };
170
171 static const struct watchdog_ops da9062_watchdog_ops = {
172         .owner = THIS_MODULE,
173         .start = da9062_wdt_start,
174         .stop = da9062_wdt_stop,
175         .ping = da9062_wdt_ping,
176         .set_timeout = da9062_wdt_set_timeout,
177         .restart = da9062_wdt_restart,
178 };
179
180 static const struct of_device_id da9062_compatible_id_table[] = {
181         { .compatible = "dlg,da9062-watchdog", },
182         { },
183 };
184
185 MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
186
187 static int da9062_wdt_probe(struct platform_device *pdev)
188 {
189         struct device *dev = &pdev->dev;
190         unsigned int timeout;
191         struct da9062 *chip;
192         struct da9062_watchdog *wdt;
193
194         chip = dev_get_drvdata(dev->parent);
195         if (!chip)
196                 return -EINVAL;
197
198         wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
199         if (!wdt)
200                 return -ENOMEM;
201
202         wdt->use_sw_pm = device_property_present(dev, "dlg,use-sw-pm");
203
204         wdt->hw = chip;
205
206         wdt->wdtdev.info = &da9062_watchdog_info;
207         wdt->wdtdev.ops = &da9062_watchdog_ops;
208         wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
209         wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
210         wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
211         wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
212         wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
213         wdt->wdtdev.parent = dev;
214
215         watchdog_set_restart_priority(&wdt->wdtdev, 128);
216
217         watchdog_set_drvdata(&wdt->wdtdev, wdt);
218         dev_set_drvdata(dev, &wdt->wdtdev);
219
220         timeout = da9062_wdt_read_timeout(wdt);
221         if (timeout)
222                 wdt->wdtdev.timeout = timeout;
223
224         /* Set timeout from DT value if available */
225         watchdog_init_timeout(&wdt->wdtdev, 0, dev);
226
227         if (timeout) {
228                 da9062_wdt_set_timeout(&wdt->wdtdev, wdt->wdtdev.timeout);
229                 set_bit(WDOG_HW_RUNNING, &wdt->wdtdev.status);
230         }
231
232         return devm_watchdog_register_device(dev, &wdt->wdtdev);
233 }
234
235 static int __maybe_unused da9062_wdt_suspend(struct device *dev)
236 {
237         struct watchdog_device *wdd = dev_get_drvdata(dev);
238         struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
239
240         if (!wdt->use_sw_pm)
241                 return 0;
242
243         if (watchdog_active(wdd))
244                 return da9062_wdt_stop(wdd);
245
246         return 0;
247 }
248
249 static int __maybe_unused da9062_wdt_resume(struct device *dev)
250 {
251         struct watchdog_device *wdd = dev_get_drvdata(dev);
252         struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
253
254         if (!wdt->use_sw_pm)
255                 return 0;
256
257         if (watchdog_active(wdd))
258                 return da9062_wdt_start(wdd);
259
260         return 0;
261 }
262
263 static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops,
264                          da9062_wdt_suspend, da9062_wdt_resume);
265
266 static struct platform_driver da9062_wdt_driver = {
267         .probe = da9062_wdt_probe,
268         .driver = {
269                 .name = "da9062-watchdog",
270                 .pm = &da9062_wdt_pm_ops,
271                 .of_match_table = da9062_compatible_id_table,
272         },
273 };
274 module_platform_driver(da9062_wdt_driver);
275
276 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
277 MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
278 MODULE_LICENSE("GPL");
279 MODULE_ALIAS("platform:da9062-watchdog");