[linux.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 <linux/pagemap.h>
#include <linux/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)
{
	return generic_file_llseek_size(file, offset, origin,
					MAX_LFS_FILESIZE, nvram_len);
}

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>
b808b1d6	23	#include <linux/pagemap.h>
7c0f6ba6	24	#include <linux/uaccess.h>
1da177e4	25	#include <asm/nvram.h>
e8222502 BH	26	#ifdef CONFIG_PPC_PMAC
	27	#include <asm/machdep.h>
	28	#endif
1da177e4 LT	29
	30	#define NVRAM_SIZE 8192
	31
613655fa	32	static DEFINE_MUTEX(nvram_mutex);
d331d830 MW	33	static ssize_t nvram_len;
d331d830 MW	34
1da177e4 LT	35	static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
1da177e4 LT	36	{
b808b1d6 AV	37	return generic_file_llseek_size(file, offset, origin,
b808b1d6 AV	38	MAX_LFS_FILESIZE, nvram_len);
1da177e4 LT	39	}
	40
	41	static ssize_t read_nvram(struct file file, char __user buf,
	42	size_t count, loff_t *ppos)
	43	{
	44	unsigned int i;
	45	char __user *p = buf;
	46
	47	if (!access_ok(VERIFY_WRITE, buf, count))
	48	return -EFAULT;
d331d830	49	if (*ppos >= nvram_len)
1da177e4	50	return 0;
d331d830	51	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count)
1da177e4 LT	52	if (__put_user(nvram_read_byte(i), p))
	53	return -EFAULT;
	54	*ppos = i;
	55	return p - buf;
	56	}
	57
	58	static ssize_t write_nvram(struct file file, const char __user buf,
	59	size_t count, loff_t *ppos)
	60	{
	61	unsigned int i;
	62	const char __user *p = buf;
	63	char c;
	64
	65	if (!access_ok(VERIFY_READ, buf, count))
	66	return -EFAULT;
d331d830	67	if (*ppos >= nvram_len)
1da177e4	68	return 0;
d331d830	69	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) {
1da177e4 LT	70	if (__get_user(c, p))
	71	return -EFAULT;
	72	nvram_write_byte(c, i);
	73	}
	74	*ppos = i;
	75	return p - buf;
	76	}
	77
55929332	78	static int nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	79	{
	80	switch(cmd) {
	81	#ifdef CONFIG_PPC_PMAC
	82	case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
	83	printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
	84	case IOC_NVRAM_GET_OFFSET: {
	85	int part, offset;
	86
e8222502	87	if (!machine_is(powermac))
1da177e4 LT	88	return -EINVAL;
	89	if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
	90	return -EFAULT;
	91	if (part < pmac_nvram_OF \|\| part > pmac_nvram_NR)
	92	return -EINVAL;
	93	offset = pmac_get_partition(part);
	94	if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
	95	return -EFAULT;
	96	break;
	97	}
	98	#endif /* CONFIG_PPC_PMAC */
	99	case IOC_NVRAM_SYNC:
	100	nvram_sync();
	101	break;
	102	default:
	103	return -EINVAL;
	104	}
	105
	106	return 0;
	107	}
	108
55929332 AB	109	static long nvram_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	110	{
	111	int ret;
	112
613655fa	113	mutex_lock(&nvram_mutex);
55929332	114	ret = nvram_ioctl(file, cmd, arg);
613655fa	115	mutex_unlock(&nvram_mutex);
55929332 AB	116
	117	return ret;
	118	}
	119
2b8693c0	120	const struct file_operations nvram_fops = {
1da177e4 LT	121	.owner = THIS_MODULE,
	122	.llseek = nvram_llseek,
	123	.read = read_nvram,
	124	.write = write_nvram,
55929332	125	.unlocked_ioctl = nvram_unlocked_ioctl,
1da177e4 LT	126	};
	127
	128	static struct miscdevice nvram_dev = {
	129	NVRAM_MINOR,
	130	"nvram",
	131	&nvram_fops
	132	};
	133
	134	int __init nvram_init(void)
	135	{
d331d830 MW	136	int ret = 0;
d331d830 MW	137
cfc53f65	138	printk(KERN_INFO "Generic non-volatile memory driver v%s\n",
1da177e4	139	NVRAM_VERSION);
d331d830 MW	140	ret = misc_register(&nvram_dev);
	141	if (ret != 0)
	142	goto out;
	143
	144	nvram_len = nvram_get_size();
	145	if (nvram_len < 0)
	146	nvram_len = NVRAM_SIZE;
	147
	148	out:
	149	return ret;
1da177e4 LT	150	}
	151
	152	void __exit nvram_cleanup(void)
	153	{
	154	misc_deregister( &nvram_dev );
	155	}
	156
	157	module_init(nvram_init);
	158	module_exit(nvram_cleanup);
	159	MODULE_LICENSE("GPL");