[net-next-2.6.git] / drivers / char / watchdog / mv64x60_wdt.c

/*
 * mv64x60_wdt.c - MV64X60 (Marvell Discovery) watchdog userspace interface
 *
 * Author: James Chapman <jchapman@katalix.com>
 *
 * Platform-specific setup code should configure the dog to generate
 * interrupt or reset as required.  This code only enables/disables
 * and services the watchdog.
 *
 * Derived from mpc8xx_wdt.c, with the following copyright.
 * 
 * 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under
 * the terms of the GNU General Public License version 2. This program
 * is licensed "as is" without any warranty of any kind, whether express
 * or implied.
 */

#include <linux/config.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <asm/mv64x60.h>
#include <asm/uaccess.h>
#include <asm/io.h>

/* MV64x60 WDC (config) register access definitions */
#define MV64x60_WDC_CTL1_MASK	(3 << 24)
#define MV64x60_WDC_CTL1(val)	((val & 3) << 24)
#define MV64x60_WDC_CTL2_MASK	(3 << 26)
#define MV64x60_WDC_CTL2(val)	((val & 3) << 26)

/* Flags bits */
#define MV64x60_WDOG_FLAG_OPENED	0
#define MV64x60_WDOG_FLAG_ENABLED	1

static unsigned long wdt_flags;
static int wdt_status;
static void __iomem *mv64x60_regs;
static int mv64x60_wdt_timeout;

static void mv64x60_wdt_reg_write(u32 val)
{
	/* Allow write only to CTL1 / CTL2 fields, retaining values in
	 * other fields.
	 */
	u32 data = readl(mv64x60_regs + MV64x60_WDT_WDC);
	data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK);
	data |= val;
	writel(data, mv64x60_regs + MV64x60_WDT_WDC);
}

static void mv64x60_wdt_service(void)
{
	/* Write 01 followed by 10 to CTL2 */
	mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01));
	mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02));
}

static void mv64x60_wdt_handler_disable(void)
{
	if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
		/* Write 01 followed by 10 to CTL1 */
		mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
		mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
		printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n");
	}
}

static void mv64x60_wdt_handler_enable(void)
{
	if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
		/* Write 01 followed by 10 to CTL1 */
		mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
		mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
		printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n");
	}
}

static int mv64x60_wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags))
		return -EBUSY;

	mv64x60_wdt_service();
	mv64x60_wdt_handler_enable();

	return 0;
}

static int mv64x60_wdt_release(struct inode *inode, struct file *file)
{
	mv64x60_wdt_service();

#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
	mv64x60_wdt_handler_disable();
#endif

	clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags);

	return 0;
}

static ssize_t mv64x60_wdt_write(struct file *file, const char *data,
				 size_t len, loff_t * ppos)
{
	if (*ppos != file->f_pos)
		return -ESPIPE;

	if (len)
		mv64x60_wdt_service();

	return len;
}

static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file,
			     unsigned int cmd, unsigned long arg)
{
	int timeout;
	static struct watchdog_info info = {
		.options = WDIOF_KEEPALIVEPING,
		.firmware_version = 0,
		.identity = "MV64x60 watchdog",
	};

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		if (copy_to_user((void *)arg, &info, sizeof(info)))
			return -EFAULT;
		break;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		if (put_user(wdt_status, (int *)arg))
			return -EFAULT;
		wdt_status &= ~WDIOF_KEEPALIVEPING;
		break;

	case WDIOC_GETTEMP:
		return -EOPNOTSUPP;

	case WDIOC_SETOPTIONS:
		return -EOPNOTSUPP;

	case WDIOC_KEEPALIVE:
		mv64x60_wdt_service();
		wdt_status |= WDIOF_KEEPALIVEPING;
		break;

	case WDIOC_SETTIMEOUT:
		return -EOPNOTSUPP;

	case WDIOC_GETTIMEOUT:
		timeout = mv64x60_wdt_timeout * HZ;
		if (put_user(timeout, (int *)arg))
			return -EFAULT;
		break;

	default:
		return -ENOIOCTLCMD;
	}

	return 0;
}

static struct file_operations mv64x60_wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = mv64x60_wdt_write,
	.ioctl = mv64x60_wdt_ioctl,
	.open = mv64x60_wdt_open,
	.release = mv64x60_wdt_release,
};

static struct miscdevice mv64x60_wdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &mv64x60_wdt_fops,
};

static int __devinit mv64x60_wdt_probe(struct device *dev)
{
	struct platform_device *pd = to_platform_device(dev);
	struct mv64x60_wdt_pdata *pdata = pd->dev.platform_data;
	int bus_clk = 133;

	mv64x60_wdt_timeout = 10;
	if (pdata) {
		mv64x60_wdt_timeout = pdata->timeout;
		bus_clk = pdata->bus_clk;
	}

	mv64x60_regs = mv64x60_get_bridge_vbase();

	writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8,
	       mv64x60_regs + MV64x60_WDT_WDC);

	return misc_register(&mv64x60_wdt_miscdev);
}

static int __devexit mv64x60_wdt_remove(struct device *dev)
{
	misc_deregister(&mv64x60_wdt_miscdev);

	mv64x60_wdt_service();
	mv64x60_wdt_handler_disable();

	return 0;
}

static struct device_driver mv64x60_wdt_driver = {
	.name = MV64x60_WDT_NAME,
	.bus = &platform_bus_type,
	.probe = mv64x60_wdt_probe,
	.remove = __devexit_p(mv64x60_wdt_remove),
};

static struct platform_device *mv64x60_wdt_dev;

static int __init mv64x60_wdt_init(void)
{
	int ret;

	printk(KERN_INFO "MV64x60 watchdog driver\n");

	mv64x60_wdt_dev = platform_device_register_simple(MV64x60_WDT_NAME,
							  -1, NULL, 0);
	if (IS_ERR(mv64x60_wdt_dev)) {
		ret = PTR_ERR(mv64x60_wdt_dev);
		goto out;
	}

	ret = driver_register(&mv64x60_wdt_driver);
      out:
	return ret;
}

static void __exit mv64x60_wdt_exit(void)
{
	driver_unregister(&mv64x60_wdt_driver);
	platform_device_unregister(mv64x60_wdt_dev);
}

module_init(mv64x60_wdt_init);
module_exit(mv64x60_wdt_exit);

MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
MODULE_DESCRIPTION("MV64x60 watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
3be10211 JC	1	/*
	2	* mv64x60_wdt.c - MV64X60 (Marvell Discovery) watchdog userspace interface
	3	*
	4	* Author: James Chapman <jchapman@katalix.com>
	5	*
	6	* Platform-specific setup code should configure the dog to generate
	7	* interrupt or reset as required. This code only enables/disables
	8	* and services the watchdog.
	9	*
	10	* Derived from mpc8xx_wdt.c, with the following copyright.
	11	*
	12	* 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under
	13	* the terms of the GNU General Public License version 2. This program
	14	* is licensed "as is" without any warranty of any kind, whether express
	15	* or implied.
	16	*/
	17
	18	#include <linux/config.h>
	19	#include <linux/fs.h>
	20	#include <linux/init.h>
	21	#include <linux/kernel.h>
	22	#include <linux/miscdevice.h>
	23	#include <linux/module.h>
	24	#include <linux/watchdog.h>
	25	#include <asm/mv64x60.h>
	26	#include <asm/uaccess.h>
	27	#include <asm/io.h>
	28
	29	/* MV64x60 WDC (config) register access definitions */
	30	#define MV64x60_WDC_CTL1_MASK (3 << 24)
	31	#define MV64x60_WDC_CTL1(val) ((val & 3) << 24)
	32	#define MV64x60_WDC_CTL2_MASK (3 << 26)
	33	#define MV64x60_WDC_CTL2(val) ((val & 3) << 26)
	34
	35	/* Flags bits */
	36	#define MV64x60_WDOG_FLAG_OPENED 0
	37	#define MV64x60_WDOG_FLAG_ENABLED 1
	38
	39	static unsigned long wdt_flags;
	40	static int wdt_status;
	41	static void __iomem *mv64x60_regs;
	42	static int mv64x60_wdt_timeout;
	43
	44	static void mv64x60_wdt_reg_write(u32 val)
	45	{
	46	/* Allow write only to CTL1 / CTL2 fields, retaining values in
	47	* other fields.
	48	*/
	49	u32 data = readl(mv64x60_regs + MV64x60_WDT_WDC);
	50	data &= ~(MV64x60_WDC_CTL1_MASK \| MV64x60_WDC_CTL2_MASK);
	51	data \|= val;
	52	writel(data, mv64x60_regs + MV64x60_WDT_WDC);
	53	}
	54
	55	static void mv64x60_wdt_service(void)
	56	{
	57	/* Write 01 followed by 10 to CTL2 */
	58	mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01));
	59	mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02));
	60	}
	61
	62	static void mv64x60_wdt_handler_disable(void)
	63	{
	64	if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
65	/* Write 01 followed by 10 to CTL1 */
66	mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
67	mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
68	printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n");
69	}
70	}
71
72	static void mv64x60_wdt_handler_enable(void)
73	{
74	if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
75	/* Write 01 followed by 10 to CTL1 */
76	mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
77	mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
78	printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n");
79	}
80	}
81
82	static int mv64x60_wdt_open(struct inode inode, struct file file)
83	{
84	if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags))
85	return -EBUSY;
86
87	mv64x60_wdt_service();
88	mv64x60_wdt_handler_enable();
89
90	return 0;
91	}
92
93	static int mv64x60_wdt_release(struct inode inode, struct file file)
94	{
95	mv64x60_wdt_service();
96
97	#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
98	mv64x60_wdt_handler_disable();
99	#endif
100
101	clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags);
102
103	return 0;
104	}
105
106	static ssize_t mv64x60_wdt_write(struct file file, const char data,
107	size_t len, loff_t * ppos)
108	{
109	if (*ppos != file->f_pos)
110	return -ESPIPE;
111
112	if (len)
113	mv64x60_wdt_service();
114
115	return len;
116	}
117
118	static int mv64x60_wdt_ioctl(struct inode inode, struct file file,
119	unsigned int cmd, unsigned long arg)
120	{
121	int timeout;
122	static struct watchdog_info info = {
123	.options = WDIOF_KEEPALIVEPING,
124	.firmware_version = 0,
125	.identity = "MV64x60 watchdog",
126	};
127
128	switch (cmd) {
129	case WDIOC_GETSUPPORT:
130	if (copy_to_user((void *)arg, &info, sizeof(info)))
131	return -EFAULT;
132	break;
133
134	case WDIOC_GETSTATUS:
135	case WDIOC_GETBOOTSTATUS:
136	if (put_user(wdt_status, (int *)arg))
137	return -EFAULT;
138	wdt_status &= ~WDIOF_KEEPALIVEPING;
139	break;
140
141	case WDIOC_GETTEMP:
142	return -EOPNOTSUPP;
143
144	case WDIOC_SETOPTIONS:
145	return -EOPNOTSUPP;
146
147	case WDIOC_KEEPALIVE:
148	mv64x60_wdt_service();
149	wdt_status \|= WDIOF_KEEPALIVEPING;
150	break;
151
152	case WDIOC_SETTIMEOUT:
153	return -EOPNOTSUPP;
154
155	case WDIOC_GETTIMEOUT:
156	timeout = mv64x60_wdt_timeout * HZ;
157	if (put_user(timeout, (int *)arg))
158	return -EFAULT;
159	break;
160
161	default:
162	return -ENOIOCTLCMD;
163	}
164
165	return 0;
166	}
167
168	static struct file_operations mv64x60_wdt_fops = {
169	.owner = THIS_MODULE,
170	.llseek = no_llseek,
171	.write = mv64x60_wdt_write,
172	.ioctl = mv64x60_wdt_ioctl,
173	.open = mv64x60_wdt_open,
174	.release = mv64x60_wdt_release,
175	};
176
177	static struct miscdevice mv64x60_wdt_miscdev = {
178	.minor = WATCHDOG_MINOR,
179	.name = "watchdog",
180	.fops = &mv64x60_wdt_fops,
181	};
182
183	static int __devinit mv64x60_wdt_probe(struct device *dev)
184	{
185	struct platform_device *pd = to_platform_device(dev);
186	struct mv64x60_wdt_pdata *pdata = pd->dev.platform_data;
187	int bus_clk = 133;
188
189	mv64x60_wdt_timeout = 10;
190	if (pdata) {
191	mv64x60_wdt_timeout = pdata->timeout;
192	bus_clk = pdata->bus_clk;
193	}
194
195	mv64x60_regs = mv64x60_get_bridge_vbase();
196
197	writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8,
198	mv64x60_regs + MV64x60_WDT_WDC);
199
200	return misc_register(&mv64x60_wdt_miscdev);
201	}
202
203	static int __devexit mv64x60_wdt_remove(struct device *dev)
204	{
205	misc_deregister(&mv64x60_wdt_miscdev);
206
207	mv64x60_wdt_service();
208	mv64x60_wdt_handler_disable();
209
210	return 0;
211	}
212
213	static struct device_driver mv64x60_wdt_driver = {
214	.name = MV64x60_WDT_NAME,
215	.bus = &platform_bus_type,
216	.probe = mv64x60_wdt_probe,
217	.remove = __devexit_p(mv64x60_wdt_remove),
218	};
219
220	static struct platform_device *mv64x60_wdt_dev;
221
222	static int __init mv64x60_wdt_init(void)
223	{
224	int ret;
225
226	printk(KERN_INFO "MV64x60 watchdog driver\n");
227
228	mv64x60_wdt_dev = platform_device_register_simple(MV64x60_WDT_NAME,
229	-1, NULL, 0);
230	if (IS_ERR(mv64x60_wdt_dev)) {
231	ret = PTR_ERR(mv64x60_wdt_dev);
232	goto out;
233	}
234
235	ret = driver_register(&mv64x60_wdt_driver);
236	out:
237	return ret;
238	}
239
240	static void __exit mv64x60_wdt_exit(void)
241	{
242	driver_unregister(&mv64x60_wdt_driver);
243	platform_device_unregister(mv64x60_wdt_dev);
244	}
245
246	module_init(mv64x60_wdt_init);
247	module_exit(mv64x60_wdt_exit);
248
249	MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
250	MODULE_DESCRIPTION("MV64x60 watchdog driver");
251	MODULE_LICENSE("GPL");
252	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);