1 // SPDX-License-Identifier: GPL-2.0+
3 * Watchdog device driver for DA9062 and DA9061 PMICs
4 * Copyright (C) 2015 Dialog Semiconductor Ltd.
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>
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
32 struct da9062_watchdog {
34 struct watchdog_device wdtdev;
38 static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
42 for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
43 if (wdt_timeout[i] >= secs)
47 return DA9062_TWDSCALE_MAX;
50 static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
52 return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F,
53 DA9062AA_WATCHDOG_MASK,
54 DA9062AA_WATCHDOG_MASK);
57 static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
60 struct da9062 *chip = wdt->hw;
63 ret = da9062_reset_watchdog_timer(wdt);
67 regmap_update_bits(chip->regmap,
69 DA9062AA_TWDSCALE_MASK,
70 DA9062_TWDSCALE_DISABLE);
72 usleep_range(150, 300);
74 return regmap_update_bits(chip->regmap,
76 DA9062AA_TWDSCALE_MASK,
80 static int da9062_wdt_start(struct watchdog_device *wdd)
82 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
83 unsigned int selector;
86 selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
87 ret = da9062_wdt_update_timeout_register(wdt, selector);
89 dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
95 static int da9062_wdt_stop(struct watchdog_device *wdd)
97 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
100 ret = regmap_update_bits(wdt->hw->regmap,
102 DA9062AA_TWDSCALE_MASK,
103 DA9062_TWDSCALE_DISABLE);
105 dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
111 static int da9062_wdt_ping(struct watchdog_device *wdd)
113 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
116 ret = da9062_reset_watchdog_timer(wdt);
118 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
124 static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
125 unsigned int timeout)
127 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
128 unsigned int selector;
131 selector = da9062_wdt_timeout_to_sel(timeout);
132 ret = da9062_wdt_update_timeout_register(wdt, selector);
134 dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
137 wdd->timeout = wdt_timeout[selector];
142 static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
145 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
146 struct i2c_client *client = to_i2c_client(wdt->hw->dev);
149 /* Don't use regmap because it is not atomic safe */
150 ret = i2c_smbus_write_byte_data(client, DA9062AA_CONTROL_F,
151 DA9062AA_SHUTDOWN_MASK);
153 dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
156 /* wait for reset to assert... */
162 static const struct watchdog_info da9062_watchdog_info = {
163 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
164 .identity = "DA9062 WDT",
167 static 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,
176 static const struct of_device_id da9062_compatible_id_table[] = {
177 { .compatible = "dlg,da9062-watchdog", },
181 MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
183 static int da9062_wdt_probe(struct platform_device *pdev)
185 struct device *dev = &pdev->dev;
188 struct da9062_watchdog *wdt;
190 chip = dev_get_drvdata(dev->parent);
194 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
198 wdt->use_sw_pm = device_property_present(dev, "dlg,use-sw-pm");
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;
211 watchdog_set_restart_priority(&wdt->wdtdev, 128);
213 watchdog_set_drvdata(&wdt->wdtdev, wdt);
214 dev_set_drvdata(dev, &wdt->wdtdev);
216 ret = devm_watchdog_register_device(dev, &wdt->wdtdev);
220 return da9062_wdt_ping(&wdt->wdtdev);
223 static int __maybe_unused da9062_wdt_suspend(struct device *dev)
225 struct watchdog_device *wdd = dev_get_drvdata(dev);
226 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
231 if (watchdog_active(wdd))
232 return da9062_wdt_stop(wdd);
237 static int __maybe_unused da9062_wdt_resume(struct device *dev)
239 struct watchdog_device *wdd = dev_get_drvdata(dev);
240 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
245 if (watchdog_active(wdd))
246 return da9062_wdt_start(wdd);
251 static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops,
252 da9062_wdt_suspend, da9062_wdt_resume);
254 static struct platform_driver da9062_wdt_driver = {
255 .probe = da9062_wdt_probe,
257 .name = "da9062-watchdog",
258 .pm = &da9062_wdt_pm_ops,
259 .of_match_table = da9062_compatible_id_table,
262 module_platform_driver(da9062_wdt_driver);
264 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
265 MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
266 MODULE_LICENSE("GPL");
267 MODULE_ALIAS("platform:da9062-watchdog");