1 // SPDX-License-Identifier: GPL-2.0-only
3  * Watchdog driver for TS-4800 based boards
5  * Copyright (c) 2015 - Savoir-faire Linux
15 #include <linux/watchdog.h>
20 	"Watchdog cannot be stopped once started (default="
36  * TS-4800 supports the following timeout values:
39  *   ---------------------
40  *     0    feed for 338ms
43  *     3    disable watchdog
45  * Keep the regmap/timeout map ordered by timeout
48 	const int timeout;  member
55 #define MAX_TIMEOUT_INDEX       (ARRAY_SIZE(ts4800_wdt_map) - 1)
59 	regmap_write(wdt->regmap, wdt->feed_offset, val);  in ts4800_write_feed()
66 	ts4800_write_feed(wdt, wdt->feed_val);  in ts4800_wdt_start()
79 				  unsigned int timeout)  in ts4800_wdt_set_timeout()  argument
85 		if (ts4800_wdt_map[i].timeout >= timeout)  in ts4800_wdt_set_timeout()
89 	wdd->timeout = ts4800_wdt_map[i].timeout;  in ts4800_wdt_set_timeout()
90 	wdt->feed_val = ts4800_wdt_map[i].regval;  in ts4800_wdt_set_timeout()
104 	.identity = "TS-4800 Watchdog",
109 	struct device *dev = &pdev->dev;  in ts4800_wdt_probe()
110 	struct device_node *np = dev->of_node;  in ts4800_wdt_probe()
120 		return -ENODEV;  in ts4800_wdt_probe()
130 	/* allocate memory for watchdog struct */  in ts4800_wdt_probe()
134 		return -ENOMEM;  in ts4800_wdt_probe()
138 	wdt->feed_offset = reg;  in ts4800_wdt_probe()
139 	wdt->regmap = syscon_node_to_regmap(syscon_np);  in ts4800_wdt_probe()
141 	if (IS_ERR(wdt->regmap)) {  in ts4800_wdt_probe()
143 		return PTR_ERR(wdt->regmap);  in ts4800_wdt_probe()
147 	wdd = &wdt->wdd;  in ts4800_wdt_probe()
148 	wdd->parent = dev;  in ts4800_wdt_probe()
149 	wdd->info = &ts4800_wdt_info;  in ts4800_wdt_probe()
150 	wdd->ops = &ts4800_wdt_ops;  in ts4800_wdt_probe()
151 	wdd->min_timeout = ts4800_wdt_map[0].timeout;  in ts4800_wdt_probe()
152 	wdd->max_timeout = ts4800_wdt_map[MAX_TIMEOUT_INDEX].timeout;  in ts4800_wdt_probe()
159 	 * As this watchdog supports only a few values, ts4800_wdt_set_timeout  in ts4800_wdt_probe()
160 	 * must be called to initialize timeout and feed_val with valid values.  in ts4800_wdt_probe()
161 	 * Default to maximum timeout if none, or an invalid one, is provided in  in ts4800_wdt_probe()
164 	if (!wdd->timeout)  in ts4800_wdt_probe()
165 		wdd->timeout = wdd->max_timeout;  in ts4800_wdt_probe()
166 	ts4800_wdt_set_timeout(wdd, wdd->timeout);  in ts4800_wdt_probe()
169 	 * The feed register is write-only, so it is not possible to determine  in ts4800_wdt_probe()
170 	 * watchdog's state. Disable it to be in a known state.  in ts4800_wdt_probe()
180 	dev_info(dev, "initialized (timeout = %d sec, nowayout = %d)\n",  in ts4800_wdt_probe()
181 		 wdd->timeout, nowayout);  in ts4800_wdt_probe()
187 	{ .compatible = "technologic,ts4800-wdt", },