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Commit 31f4233b authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Thomas Gleixner
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[MTD] User interface to Protection Registers 



This is implemented using a ioctl to switch the MTD char device into
one of the different OTP "modes", at which point read/write/seek can
operate on the selected OTP area.  Also some extra ioctls to query
for size and lock protection segments or groups.  Some example user
space utilities are provided.

Signed-off-by: default avatarNicolas Pitre <nico@cam.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent f77814dd

drivers/mtd/mtdchar.c

+110 −3
Original line number Diff line number Diff line 
/*

 * $Id: mtdchar.c,v 1.66 2005/01/05 18:05:11 dwmw2 Exp $

 * $Id: mtdchar.c,v 1.67 2005/02/08 17:45:51 nico Exp $

 *

 * Character-device access to raw MTD devices.

 *
@@ -59,6 +59,12 @@ static inline void mtdchar_devfs_exit(void) 
#define mtdchar_devfs_exit() do { } while(0)

#endif





/* Well... let's abuse the unused bits in file->f_mode for those */

#define MTD_MODE_OTP_FACT	0x1000

#define MTD_MODE_OTP_USER	0x2000

#define MTD_MODE_MASK		0xf000



static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)

{

	struct mtd_info *mtd = file->private_data;
@@ -105,6 +111,10 @@ static int mtd_open(struct inode *inode, struct file *file) 
	if ((file->f_mode & 2) && (minor & 1))

		return -EACCES;



	/* make sure the locally abused bits are initialy clear */

	if (file->f_mode & MTD_MODE_MASK)

		return -EWOULDBLOCK;



	mtd = get_mtd_device(NULL, devnum);

	

	if (!mtd)
@@ -178,7 +188,16 @@ static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t 
		if (!kbuf)

			return -ENOMEM;

		

		switch (file->f_mode & MTD_MODE_MASK) {

		case MTD_MODE_OTP_FACT:

			ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);

			break;

		case MTD_MODE_OTP_USER:

			ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);

			break;

		default:

			ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);

		}

		/* Nand returns -EBADMSG on ecc errors, but it returns

		 * the data. For our userspace tools it is important

		 * to dump areas with ecc errors !
@@ -196,6 +215,8 @@ static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t 


			count -= retlen;

			buf += retlen;

			if (retlen == 0)

				count = 0;

		}

		else {

			kfree(kbuf);
@@ -245,7 +266,20 @@ static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count 
			return -EFAULT;

		}

		

		switch (file->f_mode & MTD_MODE_MASK) {

		case MTD_MODE_OTP_FACT:

			ret = -EROFS;

			break;

		case MTD_MODE_OTP_USER:

			if (!mtd->write_user_prot_reg) {

				ret = -EOPNOTSUPP;

				break;

			}

			ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);

			break;

		default:

			ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);

		}

		if (!ret) {

			*ppos += retlen;

			total_retlen += retlen;
@@ -518,6 +552,79 @@ static int mtd_ioctl(struct inode *inode, struct file *file, 
		break;

	}



#ifdef CONFIG_MTD_OTP

	case OTPSELECT:

	{

		int mode;

		if (copy_from_user(&mode, argp, sizeof(int)))

			return -EFAULT;

		file->f_mode &= ~MTD_MODE_MASK;

		switch (mode) {

		case MTD_OTP_FACTORY:

			if (!mtd->read_fact_prot_reg)

				ret = -EOPNOTSUPP;

			else

				file->f_mode |= MTD_MODE_OTP_FACT;

			break;

		case MTD_OTP_USER:

			if (!mtd->read_fact_prot_reg)

				ret = -EOPNOTSUPP;

			else

				file->f_mode |= MTD_MODE_OTP_USER;

			break;

		default:

			ret = -EINVAL;

		case MTD_OTP_OFF:

			break;

		}

		break;

	}



	case OTPGETREGIONCOUNT:

	case OTPGETREGIONINFO:

	{

		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);

		if (!buf)

			return -ENOMEM;

		ret = -EOPNOTSUPP;

		switch (file->f_mode & MTD_MODE_MASK) {

		case MTD_MODE_OTP_FACT:

			if (mtd->get_fact_prot_info)

				ret = mtd->get_fact_prot_info(mtd, buf, 4096);

			break;

		case MTD_MODE_OTP_USER:

			if (mtd->get_user_prot_info)

				ret = mtd->get_user_prot_info(mtd, buf, 4096);

			break;

		}

		if (ret >= 0) {

			if (cmd == OTPGETREGIONCOUNT) {

				int nbr = ret / sizeof(struct otp_info);

				ret = copy_to_user(argp, &nbr, sizeof(int));

			} else

				ret = copy_to_user(argp, buf, ret);

			if (ret)

				ret = -EFAULT;

		}

		kfree(buf);

		break;

	}



	case OTPLOCK:

	{

		struct otp_info info;



		if ((file->f_mode & MTD_MODE_MASK) != MTD_MODE_OTP_USER)

			return -EINVAL;

		if (copy_from_user(&info, argp, sizeof(info)))

			return -EFAULT;

		if (!mtd->lock_user_prot_reg)

			return -EOPNOTSUPP;

		ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);

		break;

	}

#endif



	default:

		ret = -ENOTTY;

	}

include/mtd/mtd-abi.h

+10 −1
Original line number Diff line number Diff line 
/*

 * $Id: mtd-abi.h,v 1.8 2005/02/08 17:11:16 nico Exp $

 * $Id: mtd-abi.h,v 1.9 2005/02/08 17:45:52 nico Exp $

 *

 * Portions of MTD ABI definition which are shared by kernel and user space 

 */
@@ -61,6 +61,11 @@ struct mtd_oob_buf { 
#define MTD_NANDECC_AUTOPLACE	2	// Use the default placement scheme

#define MTD_NANDECC_PLACEONLY	3	// Use the given placement in the structure (Do not store ecc result on read)



/* OTP mode selection */

#define MTD_OTP_OFF		0

#define MTD_OTP_FACTORY		1

#define MTD_OTP_USER		2



struct mtd_info_user {

	uint8_t type;

	uint32_t flags;
@@ -98,6 +103,10 @@ struct otp_info { 
#define MEMGETOOBSEL		_IOR('M', 10, struct nand_oobinfo)

#define MEMGETBADBLOCK		_IOW('M', 11, loff_t)

#define MEMSETBADBLOCK		_IOW('M', 12, loff_t)

#define OTPSELECT		_IOR('M', 13, int)

#define OTPGETREGIONCOUNT	_IOW('M', 14, int)

#define OTPGETREGIONINFO	_IOW('M', 15, struct otp_info)

#define OTPLOCK		_IOR('M', 16, struct otp_info)



struct nand_oobinfo {

	uint32_t useecc;