[GitHub/mt8127/android_kernel_alcatel_ttab.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/smp_lock.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)
{
	lock_kernel();
	switch (origin) {
	case 1:
		offset += file->f_pos;
		break;
	case 2:
		offset += nvram_len;
		break;
	}
	if (offset < 0) {
		unlock_kernel();
		return -EINVAL;
	}
	file->f_pos = offset;
	unlock_kernel();
	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>
	22	#include <linux/smp_lock.h>
	23	#include <asm/uaccess.h>
	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
d331d830 MW	31	static ssize_t nvram_len;
d331d830 MW	32
1da177e4 LT	33	static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
	34	{
	35	lock_kernel();
	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;
	43	}
	44	if (offset < 0) {
	45	unlock_kernel();
	46	return -EINVAL;
	47	}
	48	file->f_pos = offset;
	49	unlock_kernel();
	50	return file->f_pos;
	51	}
	52
	53	static ssize_t read_nvram(struct file file, char __user buf,
	54	size_t count, loff_t *ppos)
	55	{
	56	unsigned int i;
	57	char __user *p = buf;
	58
	59	if (!access_ok(VERIFY_WRITE, buf, count))
	60	return -EFAULT;
d331d830	61	if (*ppos >= nvram_len)
1da177e4	62	return 0;
d331d830	63	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count)
1da177e4 LT	64	if (__put_user(nvram_read_byte(i), p))
	65	return -EFAULT;
	66	*ppos = i;
	67	return p - buf;
	68	}
	69
	70	static ssize_t write_nvram(struct file file, const char __user buf,
	71	size_t count, loff_t *ppos)
	72	{
	73	unsigned int i;
	74	const char __user *p = buf;
	75	char c;
	76
	77	if (!access_ok(VERIFY_READ, buf, count))
	78	return -EFAULT;
d331d830	79	if (*ppos >= nvram_len)
1da177e4	80	return 0;
d331d830	81	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) {
1da177e4 LT	82	if (__get_user(c, p))
	83	return -EFAULT;
	84	nvram_write_byte(c, i);
	85	}
	86	*ppos = i;
	87	return p - buf;
	88	}
	89
	90	static int nvram_ioctl(struct inode inode, struct file file,
	91	unsigned int cmd, unsigned long arg)
	92	{
	93	switch(cmd) {
	94	#ifdef CONFIG_PPC_PMAC
	95	case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
	96	printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
	97	case IOC_NVRAM_GET_OFFSET: {
	98	int part, offset;
	99
e8222502	100	if (!machine_is(powermac))
1da177e4 LT	101	return -EINVAL;
	102	if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
	103	return -EFAULT;
	104	if (part < pmac_nvram_OF \|\| part > pmac_nvram_NR)
	105	return -EINVAL;
	106	offset = pmac_get_partition(part);
	107	if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
	108	return -EFAULT;
	109	break;
	110	}
	111	#endif /* CONFIG_PPC_PMAC */
	112	case IOC_NVRAM_SYNC:
	113	nvram_sync();
	114	break;
	115	default:
	116	return -EINVAL;
	117	}
	118
	119	return 0;
	120	}
	121
2b8693c0	122	const struct file_operations nvram_fops = {
1da177e4 LT	123	.owner = THIS_MODULE,
	124	.llseek = nvram_llseek,
	125	.read = read_nvram,
	126	.write = write_nvram,
	127	.ioctl = nvram_ioctl,
	128	};
	129
	130	static struct miscdevice nvram_dev = {
	131	NVRAM_MINOR,
	132	"nvram",
	133	&nvram_fops
	134	};
	135
	136	int __init nvram_init(void)
	137	{
d331d830 MW	138	int ret = 0;
d331d830 MW	139
cfc53f65	140	printk(KERN_INFO "Generic non-volatile memory driver v%s\n",
1da177e4	141	NVRAM_VERSION);
d331d830 MW	142	ret = misc_register(&nvram_dev);
	143	if (ret != 0)
	144	goto out;
	145
	146	nvram_len = nvram_get_size();
	147	if (nvram_len < 0)
	148	nvram_len = NVRAM_SIZE;
	149
	150	out:
	151	return ret;
1da177e4 LT	152	}
	153
	154	void __exit nvram_cleanup(void)
	155	{
	156	misc_deregister( &nvram_dev );
	157	}
	158
	159	module_init(nvram_init);
	160	module_exit(nvram_cleanup);
	161	MODULE_LICENSE("GPL");