Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4f5cb243 authored by Christian Riesch's avatar Christian Riesch Committed by Brian Norris
Browse files

mtd: cfi_cmdset_0002: Add support for locking OTP memory 



This patch adds support for the locking of the one time
programmable (OTP) memory of Micron M29EW devices.

Signed-off-by: default avatarChristian Riesch <christian.riesch@omicron.at>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
parent af744750

drivers/mtd/chips/cfi_cmdset_0002.c

+84 −5
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ static int cfi_amdstd_read_user_prot_reg(struct mtd_info *, loff_t, size_t, 
					 size_t *, u_char *);

static int cfi_amdstd_write_user_prot_reg(struct mtd_info *, loff_t, size_t,

					  size_t *, u_char *);

static int cfi_amdstd_lock_user_prot_reg(struct mtd_info *, loff_t, size_t);



static int cfi_amdstd_panic_write(struct mtd_info *mtd, loff_t to, size_t len,

				  size_t *retlen, const u_char *buf);
@@ -533,6 +534,7 @@ struct mtd_info *cfi_cmdset_0002(struct map_info *map, int primary) 
	mtd->_get_fact_prot_info = cfi_amdstd_get_fact_prot_info;

	mtd->_get_user_prot_info = cfi_amdstd_get_user_prot_info;

	mtd->_write_user_prot_reg = cfi_amdstd_write_user_prot_reg;

	mtd->_lock_user_prot_reg = cfi_amdstd_lock_user_prot_reg;

	mtd->flags   = MTD_CAP_NORFLASH;

	mtd->name    = map->name;

	mtd->writesize = 1;
@@ -1153,7 +1155,7 @@ static int cfi_amdstd_read (struct mtd_info *mtd, loff_t from, size_t len, size_ 
}



typedef int (*otp_op_t)(struct map_info *map, struct flchip *chip,

			loff_t adr, size_t len, u_char *buf);

			loff_t adr, size_t len, u_char *buf, size_t grouplen);



static inline void otp_enter(struct map_info *map, struct flchip *chip,

			     loff_t adr, size_t len)
@@ -1187,7 +1189,10 @@ static inline void otp_exit(struct map_info *map, struct flchip *chip, 
	INVALIDATE_CACHED_RANGE(map, chip->start + adr, len);

}



static inline int do_read_secsi_onechip(struct map_info *map, struct flchip *chip, loff_t adr, size_t len, u_char *buf)

static inline int do_read_secsi_onechip(struct map_info *map,

					struct flchip *chip, loff_t adr,

					size_t len, u_char *buf,

					size_t grouplen)

{

	DECLARE_WAITQUEUE(wait, current);

	unsigned long timeo = jiffies + HZ;
@@ -1246,7 +1251,8 @@ static int cfi_amdstd_secsi_read (struct mtd_info *mtd, loff_t from, size_t len, 
		else

			thislen = len;



		ret = do_read_secsi_onechip(map, &cfi->chips[chipnum], ofs, thislen, buf);

		ret = do_read_secsi_onechip(map, &cfi->chips[chipnum], ofs,

					    thislen, buf, 0);

		if (ret)

			break;
@@ -1265,7 +1271,7 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip, 
				     int mode);



static int do_otp_write(struct map_info *map, struct flchip *chip, loff_t adr,

			size_t len, u_char *buf)

			size_t len, u_char *buf, size_t grouplen)

{

	int ret;

	while (len) {
@@ -1294,6 +1300,70 @@ static int do_otp_write(struct map_info *map, struct flchip *chip, loff_t adr, 
	return 0;

}



static int do_otp_lock(struct map_info *map, struct flchip *chip, loff_t adr,

		       size_t len, u_char *buf, size_t grouplen)

{

	struct cfi_private *cfi = map->fldrv_priv;

	uint8_t lockreg;

	unsigned long timeo;

	int ret;



	/* make sure area matches group boundaries */

	if ((adr != 0) || (len != grouplen))

		return -EINVAL;



	mutex_lock(&chip->mutex);

	ret = get_chip(map, chip, chip->start, FL_LOCKING);

	if (ret) {

		mutex_unlock(&chip->mutex);

		return ret;

	}

	chip->state = FL_LOCKING;



	/* Enter lock register command */

	cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chip->start, map, cfi,

			 cfi->device_type, NULL);

	cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chip->start, map, cfi,

			 cfi->device_type, NULL);

	cfi_send_gen_cmd(0x40, cfi->addr_unlock1, chip->start, map, cfi,

			 cfi->device_type, NULL);



	/* read lock register */

	lockreg = cfi_read_query(map, 0);



	/* set bit 0 to protect extended memory block */

	lockreg &= ~0x01;



	/* set bit 0 to protect extended memory block */

	/* write lock register */

	map_write(map, CMD(0xA0), chip->start);

	map_write(map, CMD(lockreg), chip->start);



	/* wait for chip to become ready */

	timeo = jiffies + msecs_to_jiffies(2);

	for (;;) {

		if (chip_ready(map, adr))

			break;



		if (time_after(jiffies, timeo)) {

			pr_err("Waiting for chip to be ready timed out.\n");

			ret = -EIO;

			break;

		}

		UDELAY(map, chip, 0, 1);

	}



	/* exit protection commands */

	map_write(map, CMD(0x90), chip->start);

	map_write(map, CMD(0x00), chip->start);



	chip->state = FL_READY;

	put_chip(map, chip, chip->start);

	mutex_unlock(&chip->mutex);



	return ret;

}



static int cfi_amdstd_otp_walk(struct mtd_info *mtd, loff_t from, size_t len,

			       size_t *retlen, u_char *buf,

			       otp_op_t action, int user_regs)
@@ -1392,7 +1462,8 @@ static int cfi_amdstd_otp_walk(struct mtd_info *mtd, loff_t from, size_t len, 
		} else if ((from < otpsize) && (len > 0)) {

			size_t size;

			size = (len < otpsize - from) ? len : otpsize - from;

			ret = action(map, chip, otpoffset + from, size, buf);

			ret = action(map, chip, otpoffset + from, size, buf,

				     otpsize);

			if (ret < 0)

				return ret;
@@ -1445,6 +1516,14 @@ static int cfi_amdstd_write_user_prot_reg(struct mtd_info *mtd, loff_t from, 
				   do_otp_write, 1);

}



static int cfi_amdstd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,

					 size_t len)

{

	size_t retlen;

	return cfi_amdstd_otp_walk(mtd, from, len, &retlen, NULL,

				   do_otp_lock, 1);

}



static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,

				     unsigned long adr, map_word datum,

				     int mode)