1/*
  2 * Copyright (C) ST-Ericsson SA 2011-2013
  3 *
  4 * License Terms: GNU General Public License v2
  5 *
  6 * Author: Mathieu Poirier <mathieu.poirier@linaro.org> for ST-Ericsson
  7 * Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson
  8 */
  9
 10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 11
 12#include <linux/module.h>
 13#include <linux/kernel.h>
 14#include <linux/moduleparam.h>
 15#include <linux/err.h>
 16#include <linux/uaccess.h>
 17#include <linux/watchdog.h>
 18#include <linux/platform_device.h>
 19#include <linux/platform_data/ux500_wdt.h>
 20
 21#include <linux/mfd/dbx500-prcmu.h>
 22
 23#define WATCHDOG_TIMEOUT 600 /* 10 minutes */
 24
 25#define WATCHDOG_MIN	0
 26#define WATCHDOG_MAX28	268435  /* 28 bit resolution in ms == 268435.455 s */
 27#define WATCHDOG_MAX32	4294967 /* 32 bit resolution in ms == 4294967.295 s */
 28
 29static unsigned int timeout = WATCHDOG_TIMEOUT;
 30module_param(timeout, uint, 0);
 31MODULE_PARM_DESC(timeout,
 32	"Watchdog timeout in seconds. default="
 33				__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
 34
 35static bool nowayout = WATCHDOG_NOWAYOUT;
 36module_param(nowayout, bool, 0);
 37MODULE_PARM_DESC(nowayout,
 38	"Watchdog cannot be stopped once started (default="
 39				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 40
 41static int ux500_wdt_start(struct watchdog_device *wdd)
 42{
 43	return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
 44}
 45
 46static int ux500_wdt_stop(struct watchdog_device *wdd)
 47{
 48	return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
 49}
 50
 51static int ux500_wdt_keepalive(struct watchdog_device *wdd)
 52{
 53	return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
 54}
 55
 56static int ux500_wdt_set_timeout(struct watchdog_device *wdd,
 57				 unsigned int timeout)
 58{
 59	ux500_wdt_stop(wdd);
 60	prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
 61	ux500_wdt_start(wdd);
 62
 63	return 0;
 64}
 65
 66static const struct watchdog_info ux500_wdt_info = {
 67	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
 68	.identity = "Ux500 WDT",
 69	.firmware_version = 1,
 70};
 71
 72static const struct watchdog_ops ux500_wdt_ops = {
 73	.owner = THIS_MODULE,
 74	.start = ux500_wdt_start,
 75	.stop  = ux500_wdt_stop,
 76	.ping  = ux500_wdt_keepalive,
 77	.set_timeout = ux500_wdt_set_timeout,
 78};
 79
 80static struct watchdog_device ux500_wdt = {
 81	.info = &ux500_wdt_info,
 82	.ops = &ux500_wdt_ops,
 83	.min_timeout = WATCHDOG_MIN,
 84	.max_timeout = WATCHDOG_MAX32,
 85};
 86
 87static int ux500_wdt_probe(struct platform_device *pdev)
 88{
 89	int ret;
 90	struct ux500_wdt_data *pdata = dev_get_platdata(&pdev->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 = &pdev->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 = watchdog_register_device(&ux500_wdt);
109	if (ret)
110		return ret;
111
112	dev_info(&pdev->dev, "initialized\n");
113
114	return 0;
115}
116
117static int ux500_wdt_remove(struct platform_device *dev)
118{
119	watchdog_unregister_device(&ux500_wdt);
120
121	return 0;
122}
123
124#ifdef CONFIG_PM
125static int ux500_wdt_suspend(struct platform_device *pdev,
126			     pm_message_t state)
127{
128	if (watchdog_active(&ux500_wdt)) {
129		ux500_wdt_stop(&ux500_wdt);
130		prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true);
131
132		prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
133		ux500_wdt_start(&ux500_wdt);
134	}
135	return 0;
136}
137
138static int ux500_wdt_resume(struct platform_device *pdev)
139{
140	if (watchdog_active(&ux500_wdt)) {
141		ux500_wdt_stop(&ux500_wdt);
142		prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
143
144		prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
145		ux500_wdt_start(&ux500_wdt);
146	}
147	return 0;
148}
149#else
150#define ux500_wdt_suspend NULL
151#define ux500_wdt_resume NULL
152#endif
153
154static struct platform_driver ux500_wdt_driver = {
155	.probe		= ux500_wdt_probe,
156	.remove		= ux500_wdt_remove,
157	.suspend	= ux500_wdt_suspend,
158	.resume		= ux500_wdt_resume,
159	.driver		= {
160		.name	= "ux500_wdt",
161	},
162};
163
164module_platform_driver(ux500_wdt_driver);
165
166MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>");
167MODULE_DESCRIPTION("Ux500 Watchdog Driver");
168MODULE_LICENSE("GPL");
169MODULE_ALIAS("platform:ux500_wdt");