1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) ST-Ericsson SA 2011-2013
  4 *
  5 * Author: Mathieu Poirier <mathieu.poirier@linaro.org> for ST-Ericsson
  6 * Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson
  7 */
  8
  9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 10
 11#include <linux/module.h>
 12#include <linux/kernel.h>
 13#include <linux/moduleparam.h>
 14#include <linux/err.h>
 15#include <linux/uaccess.h>
 16#include <linux/watchdog.h>
 17#include <linux/platform_device.h>
 18
 19#include <linux/mfd/dbx500-prcmu.h>
 20
 21#define WATCHDOG_TIMEOUT 600 /* 10 minutes */
 22
 23#define WATCHDOG_MIN	0
 24#define WATCHDOG_MAX28	268435  /* 28 bit resolution in ms == 268435.455 s */
 25
 26static unsigned int timeout = WATCHDOG_TIMEOUT;
 27module_param(timeout, uint, 0);
 28MODULE_PARM_DESC(timeout,
 29	"Watchdog timeout in seconds. default="
 30				__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
 31
 32static bool nowayout = WATCHDOG_NOWAYOUT;
 33module_param(nowayout, bool, 0);
 34MODULE_PARM_DESC(nowayout,
 35	"Watchdog cannot be stopped once started (default="
 36				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 37
 38static int db8500_wdt_start(struct watchdog_device *wdd)
 39{
 40	return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
 41}
 42
 43static int db8500_wdt_stop(struct watchdog_device *wdd)
 44{
 45	return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
 46}
 47
 48static int db8500_wdt_keepalive(struct watchdog_device *wdd)
 49{
 50	return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
 51}
 52
 53static int db8500_wdt_set_timeout(struct watchdog_device *wdd,
 54				 unsigned int timeout)
 55{
 56	db8500_wdt_stop(wdd);
 57	prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
 58	db8500_wdt_start(wdd);
 59
 60	return 0;
 61}
 62
 63static const struct watchdog_info db8500_wdt_info = {
 64	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
 65	.identity = "DB8500 WDT",
 66	.firmware_version = 1,
 67};
 68
 69static const struct watchdog_ops db8500_wdt_ops = {
 70	.owner = THIS_MODULE,
 71	.start = db8500_wdt_start,
 72	.stop  = db8500_wdt_stop,
 73	.ping  = db8500_wdt_keepalive,
 74	.set_timeout = db8500_wdt_set_timeout,
 75};
 76
 77static struct watchdog_device db8500_wdt = {
 78	.info = &db8500_wdt_info,
 79	.ops = &db8500_wdt_ops,
 80	.min_timeout = WATCHDOG_MIN,
 81	.max_timeout = WATCHDOG_MAX28,
 82};
 83
 84static int db8500_wdt_probe(struct platform_device *pdev)
 85{
 86	struct device *dev = &pdev->dev;
 87	int ret;
 88
 89	timeout = 600; /* Default to 10 minutes */
 90	db8500_wdt.parent = dev;
 91	watchdog_set_nowayout(&db8500_wdt, nowayout);
 92
 93	/* disable auto off on sleep */
 94	prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
 95
 96	/* set HW initial value */
 97	prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
 98
 99	ret = devm_watchdog_register_device(dev, &db8500_wdt);
100	if (ret)
101		return ret;
102
103	dev_info(dev, "initialized\n");
104
105	return 0;
106}
107
108static int db8500_wdt_suspend(struct platform_device *pdev,
109			     pm_message_t state)
110{
111	if (watchdog_active(&db8500_wdt)) {
112		db8500_wdt_stop(&db8500_wdt);
113		prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true);
114
115		prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
116		db8500_wdt_start(&db8500_wdt);
117	}
118	return 0;
119}
120
121static int db8500_wdt_resume(struct platform_device *pdev)
122{
123	if (watchdog_active(&db8500_wdt)) {
124		db8500_wdt_stop(&db8500_wdt);
125		prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
126
127		prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
128		db8500_wdt_start(&db8500_wdt);
129	}
130	return 0;
131}
132
133static struct platform_driver db8500_wdt_driver = {
134	.probe		= db8500_wdt_probe,
135	.suspend	= pm_ptr(db8500_wdt_suspend),
136	.resume		= pm_ptr(db8500_wdt_resume),
137	.driver		= {
138		.name	= "db8500_wdt",
139	},
140};
141
142module_platform_driver(db8500_wdt_driver);
143
144MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>");
145MODULE_DESCRIPTION("DB8500 Watchdog Driver");
146MODULE_LICENSE("GPL");
147MODULE_ALIAS("platform:db8500_wdt");