[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 <asm/uaccess.h>
#include <asm/nvram.h>
#ifdef CONFIG_PPC_PMAC
#include <asm/machdep.h>
#endif

#define NVRAM_SIZE	8192

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 inode *inode, 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;
}

const struct file_operations nvram_fops = {
	.owner		= THIS_MODULE,
	.llseek		= nvram_llseek,
	.read		= read_nvram,
	.write		= write_nvram,
	.ioctl		= nvram_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>
1da177e4 LT	22	#include <asm/uaccess.h>
1da177e4 LT	23	#include <asm/nvram.h>
e8222502 BH	24	#ifdef CONFIG_PPC_PMAC
	25	#include <asm/machdep.h>
	26	#endif
1da177e4 LT	27
	28	#define NVRAM_SIZE 8192
	29
d331d830 MW	30	static ssize_t nvram_len;
d331d830 MW	31
1da177e4 LT	32	static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
1da177e4 LT	33	{
1da177e4 LT	34	switch (origin) {
	35	case 1:
	36	offset += file->f_pos;
	37	break;
	38	case 2:
d331d830	39	offset += nvram_len;
1da177e4 LT	40	break;
1da177e4 LT	41	}
6783b9cd	42	if (offset < 0)
1da177e4	43	return -EINVAL;
6783b9cd	44
1da177e4	45	file->f_pos = offset;
6783b9cd	46
1da177e4 LT	47	return file->f_pos;
	48	}
	49
	50	static ssize_t read_nvram(struct file file, char __user buf,
	51	size_t count, loff_t *ppos)
	52	{
	53	unsigned int i;
	54	char __user *p = buf;
	55
	56	if (!access_ok(VERIFY_WRITE, buf, count))
	57	return -EFAULT;
d331d830	58	if (*ppos >= nvram_len)
1da177e4	59	return 0;
d331d830	60	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count)
1da177e4 LT	61	if (__put_user(nvram_read_byte(i), p))
	62	return -EFAULT;
	63	*ppos = i;
	64	return p - buf;
	65	}
	66
	67	static ssize_t write_nvram(struct file file, const char __user buf,
	68	size_t count, loff_t *ppos)
	69	{
	70	unsigned int i;
	71	const char __user *p = buf;
	72	char c;
	73
	74	if (!access_ok(VERIFY_READ, buf, count))
	75	return -EFAULT;
d331d830	76	if (*ppos >= nvram_len)
1da177e4	77	return 0;
d331d830	78	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) {
1da177e4 LT	79	if (__get_user(c, p))
	80	return -EFAULT;
	81	nvram_write_byte(c, i);
	82	}
	83	*ppos = i;
	84	return p - buf;
	85	}
	86
	87	static int nvram_ioctl(struct inode inode, struct file file,
	88	unsigned int cmd, unsigned long arg)
	89	{
	90	switch(cmd) {
	91	#ifdef CONFIG_PPC_PMAC
	92	case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
	93	printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
	94	case IOC_NVRAM_GET_OFFSET: {
	95	int part, offset;
	96
e8222502	97	if (!machine_is(powermac))
1da177e4 LT	98	return -EINVAL;
	99	if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
	100	return -EFAULT;
	101	if (part < pmac_nvram_OF \|\| part > pmac_nvram_NR)
	102	return -EINVAL;
	103	offset = pmac_get_partition(part);
	104	if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
	105	return -EFAULT;
	106	break;
	107	}
	108	#endif /* CONFIG_PPC_PMAC */
	109	case IOC_NVRAM_SYNC:
	110	nvram_sync();
	111	break;
	112	default:
	113	return -EINVAL;
	114	}
	115
	116	return 0;
	117	}
	118
2b8693c0	119	const struct file_operations nvram_fops = {
1da177e4 LT	120	.owner = THIS_MODULE,
	121	.llseek = nvram_llseek,
	122	.read = read_nvram,
	123	.write = write_nvram,
	124	.ioctl = nvram_ioctl,
	125	};
	126
	127	static struct miscdevice nvram_dev = {
	128	NVRAM_MINOR,
	129	"nvram",
	130	&nvram_fops
	131	};
	132
	133	int __init nvram_init(void)
	134	{
d331d830 MW	135	int ret = 0;
d331d830 MW	136
cfc53f65	137	printk(KERN_INFO "Generic non-volatile memory driver v%s\n",
1da177e4	138	NVRAM_VERSION);
d331d830 MW	139	ret = misc_register(&nvram_dev);
	140	if (ret != 0)
	141	goto out;
	142
	143	nvram_len = nvram_get_size();
	144	if (nvram_len < 0)
	145	nvram_len = NVRAM_SIZE;
	146
	147	out:
	148	return ret;
1da177e4 LT	149	}
	150
	151	void __exit nvram_cleanup(void)
	152	{
	153	misc_deregister( &nvram_dev );
	154	}
	155
	156	module_init(nvram_init);
	157	module_exit(nvram_cleanup);
	158	MODULE_LICENSE("GPL");