2 * Watchdog driver for Faraday Technology FTWDT010
4 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
6 * Inspired by the out-of-tree drivers from OpenWRT:
7 * Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/bitops.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/of_device.h>
21 #include <linux/platform_device.h>
22 #include <linux/slab.h>
23 #include <linux/watchdog.h>
25 #define FTWDT010_WDCOUNTER 0x0
26 #define FTWDT010_WDLOAD 0x4
27 #define FTWDT010_WDRESTART 0x8
28 #define FTWDT010_WDCR 0xC
30 #define WDRESTART_MAGIC 0x5AB9
32 #define WDCR_CLOCK_5MHZ BIT(4)
33 #define WDCR_WDEXT BIT(3)
34 #define WDCR_WDINTR BIT(2)
35 #define WDCR_SYS_RST BIT(1)
36 #define WDCR_ENABLE BIT(0)
38 #define WDT_CLOCK 5000000 /* 5 MHz */
41 struct watchdog_device wdd;
48 struct ftwdt010_wdt *to_ftwdt010_wdt(struct watchdog_device *wdd)
50 return container_of(wdd, struct ftwdt010_wdt, wdd);
53 static int ftwdt010_wdt_start(struct watchdog_device *wdd)
55 struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);
58 writel(wdd->timeout * WDT_CLOCK, gwdt->base + FTWDT010_WDLOAD);
59 writel(WDRESTART_MAGIC, gwdt->base + FTWDT010_WDRESTART);
60 /* set clock before enabling */
61 enable = WDCR_CLOCK_5MHZ | WDCR_SYS_RST;
62 writel(enable, gwdt->base + FTWDT010_WDCR);
64 enable |= WDCR_WDINTR;
65 enable |= WDCR_ENABLE;
66 writel(enable, gwdt->base + FTWDT010_WDCR);
71 static int ftwdt010_wdt_stop(struct watchdog_device *wdd)
73 struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);
75 writel(0, gwdt->base + FTWDT010_WDCR);
80 static int ftwdt010_wdt_ping(struct watchdog_device *wdd)
82 struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);
84 writel(WDRESTART_MAGIC, gwdt->base + FTWDT010_WDRESTART);
89 static int ftwdt010_wdt_set_timeout(struct watchdog_device *wdd,
92 wdd->timeout = timeout;
93 if (watchdog_active(wdd))
94 ftwdt010_wdt_start(wdd);
99 static irqreturn_t ftwdt010_wdt_interrupt(int irq, void *data)
101 struct ftwdt010_wdt *gwdt = data;
103 watchdog_notify_pretimeout(&gwdt->wdd);
108 static const struct watchdog_ops ftwdt010_wdt_ops = {
109 .start = ftwdt010_wdt_start,
110 .stop = ftwdt010_wdt_stop,
111 .ping = ftwdt010_wdt_ping,
112 .set_timeout = ftwdt010_wdt_set_timeout,
113 .owner = THIS_MODULE,
116 static const struct watchdog_info ftwdt010_wdt_info = {
117 .options = WDIOF_KEEPALIVEPING
120 .identity = KBUILD_MODNAME,
124 static int ftwdt010_wdt_probe(struct platform_device *pdev)
126 struct device *dev = &pdev->dev;
127 struct ftwdt010_wdt *gwdt;
132 gwdt = devm_kzalloc(dev, sizeof(*gwdt), GFP_KERNEL);
136 gwdt->base = devm_platform_ioremap_resource(pdev, 0);
137 if (IS_ERR(gwdt->base))
138 return PTR_ERR(gwdt->base);
141 gwdt->wdd.info = &ftwdt010_wdt_info;
142 gwdt->wdd.ops = &ftwdt010_wdt_ops;
143 gwdt->wdd.min_timeout = 1;
144 gwdt->wdd.max_timeout = 0xFFFFFFFF / WDT_CLOCK;
145 gwdt->wdd.parent = dev;
148 * If 'timeout-sec' unspecified in devicetree, assume a 13 second
151 gwdt->wdd.timeout = 13U;
152 watchdog_init_timeout(&gwdt->wdd, 0, dev);
154 reg = readw(gwdt->base + FTWDT010_WDCR);
155 if (reg & WDCR_ENABLE) {
156 /* Watchdog was enabled by the bootloader, disable it. */
158 writel(reg, gwdt->base + FTWDT010_WDCR);
161 irq = platform_get_irq(pdev, 0);
163 ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0,
164 "watchdog bark", gwdt);
167 gwdt->has_irq = true;
170 ret = devm_watchdog_register_device(dev, &gwdt->wdd);
172 dev_err(dev, "failed to register watchdog\n");
176 /* Set up platform driver data */
177 platform_set_drvdata(pdev, gwdt);
178 dev_info(dev, "FTWDT010 watchdog driver enabled\n");
183 static int __maybe_unused ftwdt010_wdt_suspend(struct device *dev)
185 struct ftwdt010_wdt *gwdt = dev_get_drvdata(dev);
188 reg = readw(gwdt->base + FTWDT010_WDCR);
190 writel(reg, gwdt->base + FTWDT010_WDCR);
195 static int __maybe_unused ftwdt010_wdt_resume(struct device *dev)
197 struct ftwdt010_wdt *gwdt = dev_get_drvdata(dev);
200 if (watchdog_active(&gwdt->wdd)) {
201 reg = readw(gwdt->base + FTWDT010_WDCR);
203 writel(reg, gwdt->base + FTWDT010_WDCR);
209 static const struct dev_pm_ops ftwdt010_wdt_dev_pm_ops = {
210 SET_SYSTEM_SLEEP_PM_OPS(ftwdt010_wdt_suspend,
215 static const struct of_device_id ftwdt010_wdt_match[] = {
216 { .compatible = "faraday,ftwdt010" },
217 { .compatible = "cortina,gemini-watchdog" },
220 MODULE_DEVICE_TABLE(of, ftwdt010_wdt_match);
223 static struct platform_driver ftwdt010_wdt_driver = {
224 .probe = ftwdt010_wdt_probe,
226 .name = "ftwdt010-wdt",
227 .of_match_table = of_match_ptr(ftwdt010_wdt_match),
228 .pm = &ftwdt010_wdt_dev_pm_ops,
231 module_platform_driver(ftwdt010_wdt_driver);
232 MODULE_AUTHOR("Linus Walleij");
233 MODULE_DESCRIPTION("Watchdog driver for Faraday Technology FTWDT010");
234 MODULE_LICENSE("GPL");