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#include <linux/platform_data/ux500_wdt.h>
 19
 20#include <linux/mfd/dbx500-prcmu.h>
 21
 22#define WATCHDOG_TIMEOUT 600 /* 10 minutes */
 23
 24#define WATCHDOG_MIN	0
 25#define WATCHDOG_MAX28	268435  /* 28 bit resolution in ms == 268435.455 s */
 26#define WATCHDOG_MAX32	4294967 /* 32 bit resolution in ms == 4294967.295 s */
 27
 28static unsigned int timeout = WATCHDOG_TIMEOUT;
 29module_param(timeout, uint, 0);
 30MODULE_PARM_DESC(timeout,
 31	"Watchdog timeout in seconds. default="
 32				__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
 33
 34static bool nowayout = WATCHDOG_NOWAYOUT;
 35module_param(nowayout, bool, 0);
 36MODULE_PARM_DESC(nowayout,
 37	"Watchdog cannot be stopped once started (default="
 38				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 39
 40static int ux500_wdt_start(struct watchdog_device *wdd)
 41{
 42	return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
 43}
 44
 45static int ux500_wdt_stop(struct watchdog_device *wdd)
 46{
 47	return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
 48}
 49
 50static int ux500_wdt_keepalive(struct watchdog_device *wdd)
 51{
 52	return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
 53}
 54
 55static int ux500_wdt_set_timeout(struct watchdog_device *wdd,
 56				 unsigned int timeout)
 57{
 58	ux500_wdt_stop(wdd);
 59	prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
 60	ux500_wdt_start(wdd);
 61
 62	return 0;
 63}
 64
 65static const struct watchdog_info ux500_wdt_info = {
 66	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
 67	.identity = "Ux500 WDT",
 68	.firmware_version = 1,
 69};
 70
 71static const struct watchdog_ops ux500_wdt_ops = {
 72	.owner = THIS_MODULE,
 73	.start = ux500_wdt_start,
 74	.stop  = ux500_wdt_stop,
 75	.ping  = ux500_wdt_keepalive,
 76	.set_timeout = ux500_wdt_set_timeout,
 77};
 78
 79static struct watchdog_device ux500_wdt = {
 80	.info = &ux500_wdt_info,
 81	.ops = &ux500_wdt_ops,
 82	.min_timeout = WATCHDOG_MIN,
 83	.max_timeout = WATCHDOG_MAX32,
 84};
 85
 86static int ux500_wdt_probe(struct platform_device *pdev)
 87{
 88	struct device *dev = &pdev->dev;
 89	int ret;
 90	struct ux500_wdt_data *pdata = dev_get_platdata(dev);
 91
 92	if (pdata) {
 93		if (pdata->timeout > 0)
 94			timeout = pdata->timeout;
 95		if (pdata->has_28_bits_resolution)
 96			ux500_wdt.max_timeout = WATCHDOG_MAX28;
 97	}
 98
 99	ux500_wdt.parent = dev;
100	watchdog_set_nowayout(&ux500_wdt, nowayout);
101
102	/* disable auto off on sleep */
103	prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
104
105	/* set HW initial value */
106	prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
107
108	ret = devm_watchdog_register_device(dev, &ux500_wdt);
109	if (ret)
110		return ret;
111
112	dev_info(dev, "initialized\n");
113
114	return 0;
115}
116
117#ifdef CONFIG_PM
118static int ux500_wdt_suspend(struct platform_device *pdev,
119			     pm_message_t state)
120{
121	if (watchdog_active(&ux500_wdt)) {
122		ux500_wdt_stop(&ux500_wdt);
123		prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true);
124
125		prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
126		ux500_wdt_start(&ux500_wdt);
127	}
128	return 0;
129}
130
131static int ux500_wdt_resume(struct platform_device *pdev)
132{
133	if (watchdog_active(&ux500_wdt)) {
134		ux500_wdt_stop(&ux500_wdt);
135		prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
136
137		prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
138		ux500_wdt_start(&ux500_wdt);
139	}
140	return 0;
141}
142#else
143#define ux500_wdt_suspend NULL
144#define ux500_wdt_resume NULL
145#endif
146
147static struct platform_driver ux500_wdt_driver = {
148	.probe		= ux500_wdt_probe,
149	.suspend	= ux500_wdt_suspend,
150	.resume		= ux500_wdt_resume,
151	.driver		= {
152		.name	= "ux500_wdt",
153	},
154};
155
156module_platform_driver(ux500_wdt_driver);
157
158MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>");
159MODULE_DESCRIPTION("Ux500 Watchdog Driver");
160MODULE_LICENSE("GPL");
161MODULE_ALIAS("platform:ux500_wdt");