1 // SPDX-License-Identifier: GPL-2.0+
3 * Watchdog driver for DA9063 PMICs.
5 * Copyright(c) 2012 Dialog Semiconductor Ltd.
7 * Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/watchdog.h>
14 #include <linux/platform_device.h>
15 #include <linux/uaccess.h>
16 #include <linux/slab.h>
17 #include <linux/delay.h>
18 #include <linux/mfd/da9063/registers.h>
19 #include <linux/mfd/da9063/core.h>
20 #include <linux/regmap.h>
23 * Watchdog selector to timeout in seconds.
25 * others: timeout = 2048 ms * 2^(TWDSCALE-1).
27 static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
28 #define DA9063_TWDSCALE_DISABLE 0
29 #define DA9063_TWDSCALE_MIN 1
30 #define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
31 #define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN]
32 #define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX]
33 #define DA9063_WDG_TIMEOUT wdt_timeout[3]
34 #define DA9063_RESET_PROTECTION_MS 256
36 static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
40 for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) {
41 if (wdt_timeout[i] >= secs)
45 return DA9063_TWDSCALE_MAX;
49 * Return 0 if watchdog is disabled, else non zero.
51 static unsigned int da9063_wdt_is_running(struct da9063 *da9063)
55 regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val);
57 return val & DA9063_TWDSCALE_MASK;
60 static int da9063_wdt_disable_timer(struct da9063 *da9063)
62 return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
64 DA9063_TWDSCALE_DISABLE);
68 da9063_wdt_update_timeout(struct da9063 *da9063, unsigned int timeout)
74 * The watchdog triggers a reboot if a timeout value is already
75 * programmed because the timeout value combines two functions
76 * in one: indicating the counter limit and starting the watchdog.
77 * The watchdog must be disabled to be able to change the timeout
78 * value if the watchdog is already running. Then we can set the
79 * new timeout value which enables the watchdog again.
81 ret = da9063_wdt_disable_timer(da9063);
85 usleep_range(150, 300);
86 regval = da9063_wdt_timeout_to_sel(timeout);
88 return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
89 DA9063_TWDSCALE_MASK, regval);
92 static int da9063_wdt_start(struct watchdog_device *wdd)
94 struct da9063 *da9063 = watchdog_get_drvdata(wdd);
97 ret = da9063_wdt_update_timeout(da9063, wdd->timeout);
99 dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n",
105 static int da9063_wdt_stop(struct watchdog_device *wdd)
107 struct da9063 *da9063 = watchdog_get_drvdata(wdd);
110 ret = da9063_wdt_disable_timer(da9063);
112 dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n",
118 static int da9063_wdt_ping(struct watchdog_device *wdd)
120 struct da9063 *da9063 = watchdog_get_drvdata(wdd);
123 ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
126 dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n",
132 static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
133 unsigned int timeout)
135 struct da9063 *da9063 = watchdog_get_drvdata(wdd);
139 * There are two cases when a set_timeout() will be called:
140 * 1. The watchdog is off and someone wants to set the timeout for the
142 * 2. The watchdog is already running and a new timeout value should be
145 * The watchdog can't store a timeout value not equal zero without
146 * enabling the watchdog, so the timeout must be buffered by the driver.
148 if (watchdog_active(wdd))
149 ret = da9063_wdt_update_timeout(da9063, timeout);
152 dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
155 wdd->timeout = wdt_timeout[da9063_wdt_timeout_to_sel(timeout)];
160 static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action,
163 struct da9063 *da9063 = watchdog_get_drvdata(wdd);
166 ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
169 dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n",
175 static const struct watchdog_info da9063_watchdog_info = {
176 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
177 .identity = "DA9063 Watchdog",
180 static const struct watchdog_ops da9063_watchdog_ops = {
181 .owner = THIS_MODULE,
182 .start = da9063_wdt_start,
183 .stop = da9063_wdt_stop,
184 .ping = da9063_wdt_ping,
185 .set_timeout = da9063_wdt_set_timeout,
186 .restart = da9063_wdt_restart,
189 static int da9063_wdt_probe(struct platform_device *pdev)
191 struct device *dev = &pdev->dev;
192 struct da9063 *da9063;
193 struct watchdog_device *wdd;
198 da9063 = dev_get_drvdata(dev->parent);
202 wdd = devm_kzalloc(dev, sizeof(*wdd), GFP_KERNEL);
206 wdd->info = &da9063_watchdog_info;
207 wdd->ops = &da9063_watchdog_ops;
208 wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT;
209 wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT;
210 wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS;
212 wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS;
214 watchdog_set_restart_priority(wdd, 128);
215 watchdog_set_drvdata(wdd, da9063);
217 /* Set default timeout, maybe override it with DT value, scale it */
218 wdd->timeout = DA9063_WDG_TIMEOUT;
219 watchdog_init_timeout(wdd, 0, dev);
220 da9063_wdt_set_timeout(wdd, wdd->timeout);
222 /* Change the timeout to the default value if the watchdog is running */
223 if (da9063_wdt_is_running(da9063)) {
224 da9063_wdt_update_timeout(da9063, wdd->timeout);
225 set_bit(WDOG_HW_RUNNING, &wdd->status);
228 return devm_watchdog_register_device(dev, wdd);
231 static struct platform_driver da9063_wdt_driver = {
232 .probe = da9063_wdt_probe,
234 .name = DA9063_DRVNAME_WATCHDOG,
237 module_platform_driver(da9063_wdt_driver);
239 MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
240 MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
241 MODULE_LICENSE("GPL");
242 MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);