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

/*
 * Generic /dev/nvram driver for architectures providing some
 * "generic" hooks, that is :
 *
 * nvram_read_byte, nvram_write_byte, nvram_sync, nvram_get_size
 *
 * Note that an additional hook is supported for PowerMac only
 * for getting the nvram "partition" informations
 *
 */

#define NVRAM_VERSION "1.1"

#include <linux/module.h>

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>
#include <asm/nvram.h>
#ifdef CONFIG_PPC_PMAC
#include <asm/machdep.h>
#endif

#define NVRAM_SIZE	8192

static DEFINE_MUTEX(nvram_mutex);
static ssize_t nvram_len;

static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
{
	switch (origin) {
	case 1:
		offset += file->f_pos;
		break;
	case 2:
		offset += nvram_len;
		break;
	}
	if (offset < 0)
		return -EINVAL;

	file->f_pos = offset;

	return file->f_pos;
}

static ssize_t read_nvram(struct file *file, char __user *buf,
			  size_t count, loff_t *ppos)
{
	unsigned int i;
	char __user *p = buf;

	if (!access_ok(VERIFY_WRITE, buf, count))
		return -EFAULT;
	if (*ppos >= nvram_len)
		return 0;
	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count)
		if (__put_user(nvram_read_byte(i), p))
			return -EFAULT;
	*ppos = i;
	return p - buf;
}

static ssize_t write_nvram(struct file *file, const char __user *buf,
			   size_t count, loff_t *ppos)
{
	unsigned int i;
	const char __user *p = buf;
	char c;

	if (!access_ok(VERIFY_READ, buf, count))
		return -EFAULT;
	if (*ppos >= nvram_len)
		return 0;
	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) {
		if (__get_user(c, p))
			return -EFAULT;
		nvram_write_byte(c, i);
	}
	*ppos = i;
	return p - buf;
}

static int nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	switch(cmd) {
#ifdef CONFIG_PPC_PMAC
	case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
		printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
	case IOC_NVRAM_GET_OFFSET: {
		int part, offset;

		if (!machine_is(powermac))
			return -EINVAL;
		if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
			return -EFAULT;
		if (part < pmac_nvram_OF || part > pmac_nvram_NR)
			return -EINVAL;
		offset = pmac_get_partition(part);
		if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
			return -EFAULT;
		break;
	}
#endif /* CONFIG_PPC_PMAC */
	case IOC_NVRAM_SYNC:
		nvram_sync();
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static long nvram_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	int ret;

	mutex_lock(&nvram_mutex);
	ret = nvram_ioctl(file, cmd, arg);
	mutex_unlock(&nvram_mutex);

	return ret;
}

const struct file_operations nvram_fops = {
	.owner		= THIS_MODULE,
	.llseek		= nvram_llseek,
	.read		= read_nvram,
	.write		= write_nvram,
	.unlocked_ioctl	= nvram_unlocked_ioctl,
};

static struct miscdevice nvram_dev = {
	NVRAM_MINOR,
	"nvram",
	&nvram_fops
};

int __init nvram_init(void)
{
	int ret = 0;

	printk(KERN_INFO "Generic non-volatile memory driver v%s\n",
		NVRAM_VERSION);
	ret = misc_register(&nvram_dev);
	if (ret != 0)
		goto out;

	nvram_len = nvram_get_size();
	if (nvram_len < 0)
		nvram_len = NVRAM_SIZE;

out:
	return ret;
}

void __exit nvram_cleanup(void)
{
        misc_deregister( &nvram_dev );
}

module_init(nvram_init);
module_exit(nvram_cleanup);
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Generic /dev/nvram driver for architectures providing some
	3	* "generic" hooks, that is :
	4	*
d331d830	5	* nvram_read_byte, nvram_write_byte, nvram_sync, nvram_get_size
1da177e4 LT	6	*
	7	* Note that an additional hook is supported for PowerMac only
	8	* for getting the nvram "partition" informations
	9	*
	10	*/
	11
	12	#define NVRAM_VERSION "1.1"
	13
	14	#include <linux/module.h>
	15
	16	#include <linux/types.h>
	17	#include <linux/errno.h>
	18	#include <linux/fs.h>
	19	#include <linux/miscdevice.h>
	20	#include <linux/fcntl.h>
	21	#include <linux/init.h>
613655fa	22	#include <linux/mutex.h>
1da177e4 LT	23	#include <asm/uaccess.h>
1da177e4 LT	24	#include <asm/nvram.h>
e8222502 BH	25	#ifdef CONFIG_PPC_PMAC
	26	#include <asm/machdep.h>
	27	#endif
1da177e4 LT	28
	29	#define NVRAM_SIZE 8192
	30
613655fa	31	static DEFINE_MUTEX(nvram_mutex);
d331d830 MW	32	static ssize_t nvram_len;
d331d830 MW	33
1da177e4 LT	34	static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
1da177e4 LT	35	{
1da177e4 LT	36	switch (origin) {
	37	case 1:
	38	offset += file->f_pos;
	39	break;
	40	case 2:
d331d830	41	offset += nvram_len;
1da177e4 LT	42	break;
1da177e4 LT	43	}
6783b9cd	44	if (offset < 0)
1da177e4	45	return -EINVAL;
6783b9cd	46
1da177e4	47	file->f_pos = offset;
6783b9cd	48
1da177e4 LT	49	return file->f_pos;
	50	}
	51
	52	static ssize_t read_nvram(struct file file, char __user buf,
	53	size_t count, loff_t *ppos)
	54	{
	55	unsigned int i;
	56	char __user *p = buf;
	57
	58	if (!access_ok(VERIFY_WRITE, buf, count))
	59	return -EFAULT;
d331d830	60	if (*ppos >= nvram_len)
1da177e4	61	return 0;
d331d830	62	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count)
1da177e4 LT	63	if (__put_user(nvram_read_byte(i), p))
	64	return -EFAULT;
	65	*ppos = i;
	66	return p - buf;
	67	}
	68
	69	static ssize_t write_nvram(struct file file, const char __user buf,
	70	size_t count, loff_t *ppos)
	71	{
	72	unsigned int i;
	73	const char __user *p = buf;
	74	char c;
	75
	76	if (!access_ok(VERIFY_READ, buf, count))
	77	return -EFAULT;
d331d830	78	if (*ppos >= nvram_len)
1da177e4	79	return 0;
d331d830	80	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) {
1da177e4 LT	81	if (__get_user(c, p))
	82	return -EFAULT;
	83	nvram_write_byte(c, i);
	84	}
	85	*ppos = i;
	86	return p - buf;
	87	}
	88
55929332	89	static int nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	90	{
	91	switch(cmd) {
	92	#ifdef CONFIG_PPC_PMAC
	93	case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
	94	printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
	95	case IOC_NVRAM_GET_OFFSET: {
	96	int part, offset;
	97
e8222502	98	if (!machine_is(powermac))
1da177e4 LT	99	return -EINVAL;
	100	if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
	101	return -EFAULT;
	102	if (part < pmac_nvram_OF \|\| part > pmac_nvram_NR)
	103	return -EINVAL;
	104	offset = pmac_get_partition(part);
	105	if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
	106	return -EFAULT;
	107	break;
	108	}
	109	#endif /* CONFIG_PPC_PMAC */
	110	case IOC_NVRAM_SYNC:
	111	nvram_sync();
	112	break;
	113	default:
	114	return -EINVAL;
	115	}
	116
	117	return 0;
	118	}
	119
55929332 AB	120	static long nvram_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	121	{
	122	int ret;
	123
613655fa	124	mutex_lock(&nvram_mutex);
55929332	125	ret = nvram_ioctl(file, cmd, arg);
613655fa	126	mutex_unlock(&nvram_mutex);
55929332 AB	127
	128	return ret;
	129	}
	130
2b8693c0	131	const struct file_operations nvram_fops = {
1da177e4 LT	132	.owner = THIS_MODULE,
	133	.llseek = nvram_llseek,
	134	.read = read_nvram,
	135	.write = write_nvram,
55929332	136	.unlocked_ioctl = nvram_unlocked_ioctl,
1da177e4 LT	137	};
	138
	139	static struct miscdevice nvram_dev = {
	140	NVRAM_MINOR,
	141	"nvram",
	142	&nvram_fops
	143	};
	144
	145	int __init nvram_init(void)
	146	{
d331d830 MW	147	int ret = 0;
d331d830 MW	148
cfc53f65	149	printk(KERN_INFO "Generic non-volatile memory driver v%s\n",
1da177e4	150	NVRAM_VERSION);
d331d830 MW	151	ret = misc_register(&nvram_dev);
	152	if (ret != 0)
	153	goto out;
	154
	155	nvram_len = nvram_get_size();
	156	if (nvram_len < 0)
	157	nvram_len = NVRAM_SIZE;
	158
	159	out:
	160	return ret;
1da177e4 LT	161	}
	162
	163	void __exit nvram_cleanup(void)
	164	{
	165	misc_deregister( &nvram_dev );
	166	}
	167
	168	module_init(nvram_init);
	169	module_exit(nvram_cleanup);
	170	MODULE_LICENSE("GPL");