[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 <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 0:
		break;
	case 1:
		offset += file->f_pos;
		break;
	case 2:
		offset += nvram_len;
		break;
	default:
		offset = -1;
	}
	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	36	switch (origin) {
22735068 JB	37	case 0:
22735068 JB	38	break;
1da177e4 LT	39	case 1:
	40	offset += file->f_pos;
	41	break;
	42	case 2:
d331d830	43	offset += nvram_len;
1da177e4	44	break;
22735068 JB	45	default:
22735068 JB	46	offset = -1;
1da177e4	47	}
6783b9cd	48	if (offset < 0)
1da177e4	49	return -EINVAL;
6783b9cd	50
1da177e4	51	file->f_pos = offset;
6783b9cd	52
1da177e4 LT	53	return file->f_pos;
	54	}
	55
	56	static ssize_t read_nvram(struct file file, char __user buf,
	57	size_t count, loff_t *ppos)
	58	{
	59	unsigned int i;
	60	char __user *p = buf;
	61
	62	if (!access_ok(VERIFY_WRITE, buf, count))
	63	return -EFAULT;
d331d830	64	if (*ppos >= nvram_len)
1da177e4	65	return 0;
d331d830	66	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count)
1da177e4 LT	67	if (__put_user(nvram_read_byte(i), p))
	68	return -EFAULT;
	69	*ppos = i;
	70	return p - buf;
	71	}
	72
	73	static ssize_t write_nvram(struct file file, const char __user buf,
	74	size_t count, loff_t *ppos)
	75	{
	76	unsigned int i;
	77	const char __user *p = buf;
	78	char c;
	79
	80	if (!access_ok(VERIFY_READ, buf, count))
	81	return -EFAULT;
d331d830	82	if (*ppos >= nvram_len)
1da177e4	83	return 0;
d331d830	84	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) {
1da177e4 LT	85	if (__get_user(c, p))
	86	return -EFAULT;
	87	nvram_write_byte(c, i);
	88	}
	89	*ppos = i;
	90	return p - buf;
	91	}
	92
55929332	93	static int nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	94	{
	95	switch(cmd) {
	96	#ifdef CONFIG_PPC_PMAC
	97	case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
	98	printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
	99	case IOC_NVRAM_GET_OFFSET: {
	100	int part, offset;
	101
e8222502	102	if (!machine_is(powermac))
1da177e4 LT	103	return -EINVAL;
	104	if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
	105	return -EFAULT;
	106	if (part < pmac_nvram_OF \|\| part > pmac_nvram_NR)
	107	return -EINVAL;
	108	offset = pmac_get_partition(part);
	109	if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
	110	return -EFAULT;
	111	break;
	112	}
	113	#endif /* CONFIG_PPC_PMAC */
	114	case IOC_NVRAM_SYNC:
	115	nvram_sync();
	116	break;
	117	default:
	118	return -EINVAL;
	119	}
	120
	121	return 0;
	122	}
	123
55929332 AB	124	static long nvram_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	125	{
	126	int ret;
	127
613655fa	128	mutex_lock(&nvram_mutex);
55929332	129	ret = nvram_ioctl(file, cmd, arg);
613655fa	130	mutex_unlock(&nvram_mutex);
55929332 AB	131
	132	return ret;
	133	}
	134
2b8693c0	135	const struct file_operations nvram_fops = {
1da177e4 LT	136	.owner = THIS_MODULE,
	137	.llseek = nvram_llseek,
	138	.read = read_nvram,
	139	.write = write_nvram,
55929332	140	.unlocked_ioctl = nvram_unlocked_ioctl,
1da177e4 LT	141	};
	142
	143	static struct miscdevice nvram_dev = {
	144	NVRAM_MINOR,
	145	"nvram",
	146	&nvram_fops
	147	};
	148
	149	int __init nvram_init(void)
	150	{
d331d830 MW	151	int ret = 0;
d331d830 MW	152
cfc53f65	153	printk(KERN_INFO "Generic non-volatile memory driver v%s\n",
1da177e4	154	NVRAM_VERSION);
d331d830 MW	155	ret = misc_register(&nvram_dev);
	156	if (ret != 0)
	157	goto out;
	158
	159	nvram_len = nvram_get_size();
	160	if (nvram_len < 0)
	161	nvram_len = NVRAM_SIZE;
	162
	163	out:
	164	return ret;
1da177e4 LT	165	}
	166
	167	void __exit nvram_cleanup(void)
	168	{
	169	misc_deregister( &nvram_dev );
	170	}
	171
	172	module_init(nvram_init);
	173	module_exit(nvram_cleanup);
	174	MODULE_LICENSE("GPL");