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/regmap.h>
22 static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
23 #define DA9062_TWDSCALE_DISABLE 0
24 #define DA9062_TWDSCALE_MIN 1
25 #define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
26 #define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN]
27 #define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX]
28 #define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1]
29 #define DA9062_RESET_PROTECTION_MS 300
31 struct da9062_watchdog {
33 struct watchdog_device wdtdev;
36 static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
40 for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
41 if (wdt_timeout[i] >= secs)
45 return DA9062_TWDSCALE_MAX;
48 static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
50 return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F,
51 DA9062AA_WATCHDOG_MASK,
52 DA9062AA_WATCHDOG_MASK);
55 static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
58 struct da9062 *chip = wdt->hw;
61 ret = da9062_reset_watchdog_timer(wdt);
65 regmap_update_bits(chip->regmap,
67 DA9062AA_TWDSCALE_MASK,
68 DA9062_TWDSCALE_DISABLE);
70 usleep_range(150, 300);
72 return regmap_update_bits(chip->regmap,
74 DA9062AA_TWDSCALE_MASK,
78 static int da9062_wdt_start(struct watchdog_device *wdd)
80 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
81 unsigned int selector;
84 selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
85 ret = da9062_wdt_update_timeout_register(wdt, selector);
87 dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
93 static int da9062_wdt_stop(struct watchdog_device *wdd)
95 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
98 ret = da9062_reset_watchdog_timer(wdt);
100 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
105 ret = regmap_update_bits(wdt->hw->regmap,
107 DA9062AA_TWDSCALE_MASK,
108 DA9062_TWDSCALE_DISABLE);
110 dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
116 static int da9062_wdt_ping(struct watchdog_device *wdd)
118 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
121 ret = da9062_reset_watchdog_timer(wdt);
123 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
129 static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
130 unsigned int timeout)
132 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
133 unsigned int selector;
136 selector = da9062_wdt_timeout_to_sel(timeout);
137 ret = da9062_wdt_update_timeout_register(wdt, selector);
139 dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
142 wdd->timeout = wdt_timeout[selector];
147 static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
150 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
151 struct i2c_client *client = to_i2c_client(wdt->hw->dev);
154 /* Don't use regmap because it is not atomic safe */
155 ret = i2c_smbus_write_byte_data(client, DA9062AA_CONTROL_F,
156 DA9062AA_SHUTDOWN_MASK);
158 dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
161 /* wait for reset to assert... */
167 static const struct watchdog_info da9062_watchdog_info = {
168 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
169 .identity = "DA9062 WDT",
172 static const struct watchdog_ops da9062_watchdog_ops = {
173 .owner = THIS_MODULE,
174 .start = da9062_wdt_start,
175 .stop = da9062_wdt_stop,
176 .ping = da9062_wdt_ping,
177 .set_timeout = da9062_wdt_set_timeout,
178 .restart = da9062_wdt_restart,
181 static const struct of_device_id da9062_compatible_id_table[] = {
182 { .compatible = "dlg,da9062-watchdog", },
186 MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
188 static int da9062_wdt_probe(struct platform_device *pdev)
190 struct device *dev = &pdev->dev;
193 struct da9062_watchdog *wdt;
195 chip = dev_get_drvdata(dev->parent);
199 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
205 wdt->wdtdev.info = &da9062_watchdog_info;
206 wdt->wdtdev.ops = &da9062_watchdog_ops;
207 wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
208 wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
209 wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
210 wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
211 wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
212 wdt->wdtdev.parent = dev;
214 watchdog_set_restart_priority(&wdt->wdtdev, 128);
216 watchdog_set_drvdata(&wdt->wdtdev, wdt);
217 dev_set_drvdata(dev, &wdt->wdtdev);
219 ret = devm_watchdog_register_device(dev, &wdt->wdtdev);
223 return da9062_wdt_ping(&wdt->wdtdev);
226 static int __maybe_unused da9062_wdt_suspend(struct device *dev)
228 struct watchdog_device *wdd = dev_get_drvdata(dev);
230 if (watchdog_active(wdd))
231 return da9062_wdt_stop(wdd);
236 static int __maybe_unused da9062_wdt_resume(struct device *dev)
238 struct watchdog_device *wdd = dev_get_drvdata(dev);
240 if (watchdog_active(wdd))
241 return da9062_wdt_start(wdd);
246 static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops,
247 da9062_wdt_suspend, da9062_wdt_resume);
249 static struct platform_driver da9062_wdt_driver = {
250 .probe = da9062_wdt_probe,
252 .name = "da9062-watchdog",
253 .pm = &da9062_wdt_pm_ops,
254 .of_match_table = da9062_compatible_id_table,
257 module_platform_driver(da9062_wdt_driver);
259 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
260 MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
261 MODULE_LICENSE("GPL");
262 MODULE_ALIAS("platform:da9062-watchdog");