[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / watchdog / pnx833x_wdt.c

/*
 *  PNX833x Hardware Watchdog Driver
 *  Copyright 2008 NXP Semiconductors
 *  Daniel Laird <daniel.j.laird@nxp.com>
 *  Andre McCurdy <andre.mccurdy@nxp.com>
 *
 *  Heavily based upon - IndyDog	0.3
 *  A Hardware Watchdog Device for SGI IP22
 *
 * (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 * based on softdog.c by Alan Cox <alan@redhat.com>
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <asm/mach-pnx833x/pnx833x.h>

#define PFX "pnx833x: "
#define WATCHDOG_TIMEOUT 30		/* 30 sec Maximum timeout */
#define WATCHDOG_COUNT_FREQUENCY 68000000U /* Watchdog counts at 68MHZ. */

/** CONFIG block */
#define PNX833X_CONFIG                      (0x07000U)
#define PNX833X_CONFIG_CPU_WATCHDOG         (0x54)
#define PNX833X_CONFIG_CPU_WATCHDOG_COMPARE (0x58)
#define PNX833X_CONFIG_CPU_COUNTERS_CONTROL (0x1c)

/** RESET block */
#define PNX833X_RESET                       (0x08000U)
#define PNX833X_RESET_CONFIG                (0x08)

static int pnx833x_wdt_alive;

/* Set default timeout in MHZ.*/
static int pnx833x_wdt_timeout = (WATCHDOG_TIMEOUT * WATCHDOG_COUNT_FREQUENCY);
module_param(pnx833x_wdt_timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default="
			__MODULE_STRING(pnx833x_wdt_timeout) "(30 seconds).");

static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
					__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static int start_enabled = 1;
module_param(start_enabled, int, 0);
MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion "
				"(default=" __MODULE_STRING(start_enabled) ")");

static void pnx833x_wdt_start(void)
{
	/* Enable watchdog causing reset. */
	PNX833X_REG(PNX833X_RESET + PNX833X_RESET_CONFIG) |= 0x1;
	/* Set timeout.*/
	PNX833X_REG(PNX833X_CONFIG +
		PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
	/* Enable watchdog. */
	PNX833X_REG(PNX833X_CONFIG +
				PNX833X_CONFIG_CPU_COUNTERS_CONTROL) |= 0x1;

	printk(KERN_INFO PFX "Started watchdog timer.\n");
}

static void pnx833x_wdt_stop(void)
{
	/* Disable watchdog causing reset. */
	PNX833X_REG(PNX833X_RESET + PNX833X_CONFIG) &= 0xFFFFFFFE;
	/* Disable watchdog.*/
	PNX833X_REG(PNX833X_CONFIG +
			PNX833X_CONFIG_CPU_COUNTERS_CONTROL) &= 0xFFFFFFFE;

	printk(KERN_INFO PFX "Stopped watchdog timer.\n");
}

static void pnx833x_wdt_ping(void)
{
	PNX833X_REG(PNX833X_CONFIG +
		PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
}

/*
 *	Allow only one person to hold it open
 */
static int pnx833x_wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &pnx833x_wdt_alive))
		return -EBUSY;

	if (nowayout)
		__module_get(THIS_MODULE);

	/* Activate timer */
	if (!start_enabled)
		pnx833x_wdt_start();

	pnx833x_wdt_ping();

	printk(KERN_INFO "Started watchdog timer.\n");

	return nonseekable_open(inode, file);
}

static int pnx833x_wdt_release(struct inode *inode, struct file *file)
{
	/* Shut off the timer.
	 * Lock it in if it's a module and we defined ...NOWAYOUT */
	if (!nowayout)
		pnx833x_wdt_stop(); /* Turn the WDT off */

	clear_bit(0, &pnx833x_wdt_alive);
	return 0;
}

static ssize_t pnx833x_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
{
	/* Refresh the timer. */
	if (len)
		pnx833x_wdt_ping();

	return len;
}

static long pnx833x_wdt_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	int options, new_timeout = 0;
	uint32_t timeout, timeout_left = 0;

	static struct watchdog_info ident = {
		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
		.firmware_version = 0,
		.identity = "Hardware Watchdog for PNX833x",
	};

	switch (cmd) {
	default:
		return -ENOTTY;

	case WDIOC_GETSUPPORT:
		if (copy_to_user((struct watchdog_info *)arg,
				 &ident, sizeof(ident)))
			return -EFAULT;
		return 0;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, (int *)arg);

	case WDIOC_SETOPTIONS:
		if (get_user(options, (int *)arg))
			return -EFAULT;

		if (options & WDIOS_DISABLECARD)
			pnx833x_wdt_stop();

		if (options & WDIOS_ENABLECARD)
			pnx833x_wdt_start();

		return 0;

	case WDIOC_KEEPALIVE:
		pnx833x_wdt_ping();
		return 0;

	case WDIOC_SETTIMEOUT:
	{
		if (get_user(new_timeout, (int *)arg))
			return -EFAULT;

		pnx833x_wdt_timeout = new_timeout;
		PNX833X_REG(PNX833X_CONFIG +
			PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = new_timeout;
		return put_user(new_timeout, (int *)arg);
	}

	case WDIOC_GETTIMEOUT:
		timeout = PNX833X_REG(PNX833X_CONFIG +
					PNX833X_CONFIG_CPU_WATCHDOG_COMPARE);
		return put_user(timeout, (int *)arg);

	case WDIOC_GETTIMELEFT:
		timeout_left = PNX833X_REG(PNX833X_CONFIG +
						PNX833X_CONFIG_CPU_WATCHDOG);
		return put_user(timeout_left, (int *)arg);

	}
}

static int pnx833x_wdt_notify_sys(struct notifier_block *this,
					unsigned long code, void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		pnx833x_wdt_stop(); /* Turn the WDT off */

	return NOTIFY_DONE;
}

static const struct file_operations pnx833x_wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= pnx833x_wdt_write,
	.unlocked_ioctl	= pnx833x_wdt_ioctl,
	.open		= pnx833x_wdt_open,
	.release	= pnx833x_wdt_release,
};

static struct miscdevice pnx833x_wdt_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &pnx833x_wdt_fops,
};

static struct notifier_block pnx833x_wdt_notifier = {
	.notifier_call = pnx833x_wdt_notify_sys,
};

static char banner[] __initdata =
	KERN_INFO PFX "Hardware Watchdog Timer for PNX833x: Version 0.1\n";

static int __init watchdog_init(void)
{
	int ret, cause;

	/* Lets check the reason for the reset.*/
	cause = PNX833X_REG(PNX833X_RESET);
	/*If bit 31 is set then watchdog was cause of reset.*/
	if (cause & 0x80000000) {
		printk(KERN_INFO PFX "The system was previously reset due to "
			"the watchdog firing - please investigate...\n");
	}

	ret = register_reboot_notifier(&pnx833x_wdt_notifier);
	if (ret) {
		printk(KERN_ERR PFX
			"cannot register reboot notifier (err=%d)\n", ret);
		return ret;
	}

	ret = misc_register(&pnx833x_wdt_miscdev);
	if (ret) {
		printk(KERN_ERR PFX
			"cannot register miscdev on minor=%d (err=%d)\n",
			WATCHDOG_MINOR, ret);
		unregister_reboot_notifier(&pnx833x_wdt_notifier);
		return ret;
	}

	printk(banner);
	if (start_enabled)
		pnx833x_wdt_start();

	return 0;
}

static void __exit watchdog_exit(void)
{
	misc_deregister(&pnx833x_wdt_miscdev);
	unregister_reboot_notifier(&pnx833x_wdt_notifier);
}

module_init(watchdog_init);
module_exit(watchdog_exit);

MODULE_AUTHOR("Daniel Laird/Andre McCurdy");
MODULE_DESCRIPTION("Hardware Watchdog Device for PNX833x");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
33c050c5 DL	1	/*
	2	* PNX833x Hardware Watchdog Driver
	3	* Copyright 2008 NXP Semiconductors
	4	* Daniel Laird <daniel.j.laird@nxp.com>
	5	* Andre McCurdy <andre.mccurdy@nxp.com>
	6	*
	7	* Heavily based upon - IndyDog 0.3
	8	* A Hardware Watchdog Device for SGI IP22
	9	*
	10	* (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, All Rights Reserved.
	11	*
	12	* This program is free software; you can redistribute it and/or
	13	* modify it under the terms of the GNU General Public License
	14	* as published by the Free Software Foundation; either version
	15	* 2 of the License, or (at your option) any later version.
	16	*
	17	* based on softdog.c by Alan Cox <alan@redhat.com>
	18	*/
	19
	20	#include <linux/module.h>
	21	#include <linux/moduleparam.h>
	22	#include <linux/types.h>
	23	#include <linux/kernel.h>
	24	#include <linux/fs.h>
	25	#include <linux/mm.h>
	26	#include <linux/miscdevice.h>
	27	#include <linux/watchdog.h>
	28	#include <linux/notifier.h>
	29	#include <linux/reboot.h>
	30	#include <linux/init.h>
	31	#include <asm/mach-pnx833x/pnx833x.h>
	32
	33	#define PFX "pnx833x: "
	34	#define WATCHDOG_TIMEOUT 30 /* 30 sec Maximum timeout */
	35	#define WATCHDOG_COUNT_FREQUENCY 68000000U /* Watchdog counts at 68MHZ. */
	36
	37	/** CONFIG block */
	38	#define PNX833X_CONFIG (0x07000U)
	39	#define PNX833X_CONFIG_CPU_WATCHDOG (0x54)
	40	#define PNX833X_CONFIG_CPU_WATCHDOG_COMPARE (0x58)
	41	#define PNX833X_CONFIG_CPU_COUNTERS_CONTROL (0x1c)
	42
	43	/** RESET block */
	44	#define PNX833X_RESET (0x08000U)
	45	#define PNX833X_RESET_CONFIG (0x08)
	46
	47	static int pnx833x_wdt_alive;
	48
	49	/* Set default timeout in MHZ.*/
	50	static int pnx833x_wdt_timeout = (WATCHDOG_TIMEOUT * WATCHDOG_COUNT_FREQUENCY);
	51	module_param(pnx833x_wdt_timeout, int, 0);
	52	MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default="
	53	__MODULE_STRING(pnx833x_wdt_timeout) "(30 seconds).");
	54
	55	static int nowayout = WATCHDOG_NOWAYOUT;
	56	module_param(nowayout, int, 0);
	57	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
	58	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	59
	60	static int start_enabled = 1;
	61	module_param(start_enabled, int, 0);
	62	MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion "
	63	"(default=" __MODULE_STRING(start_enabled) ")");
	64
65	static void pnx833x_wdt_start(void)
66	{
67	/* Enable watchdog causing reset. */
68	PNX833X_REG(PNX833X_RESET + PNX833X_RESET_CONFIG) \|= 0x1;
69	/* Set timeout.*/
70	PNX833X_REG(PNX833X_CONFIG +
71	PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
72	/* Enable watchdog. */
73	PNX833X_REG(PNX833X_CONFIG +
74	PNX833X_CONFIG_CPU_COUNTERS_CONTROL) \|= 0x1;
75
76	printk(KERN_INFO PFX "Started watchdog timer.\n");
77	}
78
79	static void pnx833x_wdt_stop(void)
80	{
81	/* Disable watchdog causing reset. */
82	PNX833X_REG(PNX833X_RESET + PNX833X_CONFIG) &= 0xFFFFFFFE;
83	/* Disable watchdog.*/
84	PNX833X_REG(PNX833X_CONFIG +
85	PNX833X_CONFIG_CPU_COUNTERS_CONTROL) &= 0xFFFFFFFE;
86
87	printk(KERN_INFO PFX "Stopped watchdog timer.\n");
88	}
89
90	static void pnx833x_wdt_ping(void)
91	{
92	PNX833X_REG(PNX833X_CONFIG +
93	PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
94	}
95
96	/*
97	* Allow only one person to hold it open
98	*/
99	static int pnx833x_wdt_open(struct inode inode, struct file file)
100	{
101	if (test_and_set_bit(0, &pnx833x_wdt_alive))
102	return -EBUSY;
103
104	if (nowayout)
105	__module_get(THIS_MODULE);
106
107	/* Activate timer */
108	if (!start_enabled)
109	pnx833x_wdt_start();
110
111	pnx833x_wdt_ping();
112
113	printk(KERN_INFO "Started watchdog timer.\n");
114
115	return nonseekable_open(inode, file);
116	}
117
118	static int pnx833x_wdt_release(struct inode inode, struct file file)
119	{
120	/* Shut off the timer.
121	* Lock it in if it's a module and we defined ...NOWAYOUT */
122	if (!nowayout)
123	pnx833x_wdt_stop(); /* Turn the WDT off */
124
125	clear_bit(0, &pnx833x_wdt_alive);
126	return 0;
127	}
128
129	static ssize_t pnx833x_wdt_write(struct file file, const char data, size_t len, loff_t *ppos)
130	{
131	/* Refresh the timer. */
132	if (len)
133	pnx833x_wdt_ping();
134
135	return len;
136	}
137
138	static long pnx833x_wdt_ioctl(struct file *file, unsigned int cmd,
139	unsigned long arg)
140	{
141	int options, new_timeout = 0;
142	uint32_t timeout, timeout_left = 0;
143
144	static struct watchdog_info ident = {
145	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT,
146	.firmware_version = 0,
147	.identity = "Hardware Watchdog for PNX833x",
148	};
149
150	switch (cmd) {
151	default:
152	return -ENOTTY;
153
154	case WDIOC_GETSUPPORT:
155	if (copy_to_user((struct watchdog_info *)arg,
156	&ident, sizeof(ident)))
157	return -EFAULT;
158	return 0;
159
160	case WDIOC_GETSTATUS:
161	case WDIOC_GETBOOTSTATUS:
162	return put_user(0, (int *)arg);
163
164	case WDIOC_SETOPTIONS:
165	if (get_user(options, (int *)arg))
166	return -EFAULT;
167
168	if (options & WDIOS_DISABLECARD)
169	pnx833x_wdt_stop();
170
171	if (options & WDIOS_ENABLECARD)
172	pnx833x_wdt_start();
173
174	return 0;
175
176	case WDIOC_KEEPALIVE:
177	pnx833x_wdt_ping();
178	return 0;
179
180	case WDIOC_SETTIMEOUT:
181	{
182	if (get_user(new_timeout, (int *)arg))
183	return -EFAULT;
184
185	pnx833x_wdt_timeout = new_timeout;
186	PNX833X_REG(PNX833X_CONFIG +
187	PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = new_timeout;
188	return put_user(new_timeout, (int *)arg);
189	}
190
191	case WDIOC_GETTIMEOUT:
192	timeout = PNX833X_REG(PNX833X_CONFIG +
193	PNX833X_CONFIG_CPU_WATCHDOG_COMPARE);
194	return put_user(timeout, (int *)arg);
195
196	case WDIOC_GETTIMELEFT:
197	timeout_left = PNX833X_REG(PNX833X_CONFIG +
198	PNX833X_CONFIG_CPU_WATCHDOG);
199	return put_user(timeout_left, (int *)arg);
200
201	}
202	}
203
204	static int pnx833x_wdt_notify_sys(struct notifier_block *this,
205	unsigned long code, void *unused)
206	{
207	if (code == SYS_DOWN \|\| code == SYS_HALT)
208	pnx833x_wdt_stop(); /* Turn the WDT off */
209
210	return NOTIFY_DONE;
211	}
212
213	static const struct file_operations pnx833x_wdt_fops = {
214	.owner = THIS_MODULE,
215	.llseek = no_llseek,
216	.write = pnx833x_wdt_write,
217	.unlocked_ioctl = pnx833x_wdt_ioctl,
218	.open = pnx833x_wdt_open,
219	.release = pnx833x_wdt_release,
220	};
221
222	static struct miscdevice pnx833x_wdt_miscdev = {
223	.minor = WATCHDOG_MINOR,
224	.name = "watchdog",
225	.fops = &pnx833x_wdt_fops,
226	};
227
228	static struct notifier_block pnx833x_wdt_notifier = {
229	.notifier_call = pnx833x_wdt_notify_sys,
230	};
231
232	static char banner[] __initdata =
233	KERN_INFO PFX "Hardware Watchdog Timer for PNX833x: Version 0.1\n";
234
235	static int __init watchdog_init(void)
236	{
237	int ret, cause;
238
239	/* Lets check the reason for the reset.*/
240	cause = PNX833X_REG(PNX833X_RESET);
241	/If bit 31 is set then watchdog was cause of reset./
242	if (cause & 0x80000000) {
243	printk(KERN_INFO PFX "The system was previously reset due to "
244	"the watchdog firing - please investigate...\n");
245	}
246
247	ret = register_reboot_notifier(&pnx833x_wdt_notifier);
248	if (ret) {
249	printk(KERN_ERR PFX
250	"cannot register reboot notifier (err=%d)\n", ret);
251	return ret;
252	}
253
254	ret = misc_register(&pnx833x_wdt_miscdev);
255	if (ret) {
256	printk(KERN_ERR PFX
257	"cannot register miscdev on minor=%d (err=%d)\n",
258	WATCHDOG_MINOR, ret);
259	unregister_reboot_notifier(&pnx833x_wdt_notifier);
260	return ret;
261	}
262
263	printk(banner);
264	if (start_enabled)
265	pnx833x_wdt_start();
266
267	return 0;
268	}
269
270	static void __exit watchdog_exit(void)
271	{
272	misc_deregister(&pnx833x_wdt_miscdev);
273	unregister_reboot_notifier(&pnx833x_wdt_notifier);
274	}
275
276	module_init(watchdog_init);
277	module_exit(watchdog_exit);
278
279	MODULE_AUTHOR("Daniel Laird/Andre McCurdy");
280	MODULE_DESCRIPTION("Hardware Watchdog Device for PNX833x");
281	MODULE_LICENSE("GPL");
282	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);