diff mbox series

[v3] mtd: rawnand: Add support for Macronix NAND randomizer

Message ID 1567676229-23414-1-git-send-email-masonccyang@mxic.com.tw
State Changes Requested
Delegated to: Miquel Raynal
Headers show
Series [v3] mtd: rawnand: Add support for Macronix NAND randomizer | expand

Commit Message

Mason Yang Sept. 5, 2019, 9:37 a.m. UTC
Macronix NANDs support randomizer operation for user data scrambled,
which can be enabled with a SET_FEATURE.

User data written to the NAND device without randomizer is still readable
after randomizer function enabled.
The penalty of randomizer are subpage accesses prohibited and more time
period is needed in program operation and entering deep power-down mode.
i.e., tPROG 300us to 340us(randomizer enabled)

For more high-reliability concern, if subpage write not available with
hardware ECC and then to enable randomizer is recommended by default.
Driver checks byte 167 of Vendor Blocks in ONFI parameter page table
to see if this high-reliability function is supported. By adding a new
specific DT property in children nodes to enable randomizer function.
i.e.,

	nand: nand-controller@unit-address {

		nand@0 {
			reg = <0>;
			mxic,enable-randomizer-otp;
		};
	};

--
changelog
v3:
To enable randomizer by specific DT property in children nodes,
mxic,enable-randomizer-otp;

v2:
To enable randomizer by checking chip options NAND_NO_SUBPAGE_WRITE

v1:
To enable randomizer by sys-fs

Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
---
 drivers/mtd/nand/raw/nand_macronix.c | 64 ++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

Comments

Miquel Raynal Oct. 7, 2019, 8:18 a.m. UTC | #1
Hi Mason,

Mason Yang <masonccyang@mxic.com.tw> wrote on Thu,  5 Sep 2019 17:37:09
+0800:

> Macronix NANDs support randomizer operation for user data scrambled,
> which can be enabled with a SET_FEATURE.
> 
> User data written to the NAND device without randomizer is still readable
> after randomizer function enabled.
> The penalty of randomizer are subpage accesses prohibited and more time
> period is needed in program operation and entering deep power-down mode.
> i.e., tPROG 300us to 340us(randomizer enabled)
> 
> For more high-reliability concern, if subpage write not available with
> hardware ECC and then to enable randomizer is recommended by default.
> Driver checks byte 167 of Vendor Blocks in ONFI parameter page table
> to see if this high-reliability function is supported. By adding a new
> specific DT property in children nodes to enable randomizer function.
> i.e.,
> 
> 	nand: nand-controller@unit-address {
> 
> 		nand@0 {
> 			reg = <0>;
> 			mxic,enable-randomizer-otp;
> 		};
> 	};
> 
> --
> changelog
> v3:
> To enable randomizer by specific DT property in children nodes,
> mxic,enable-randomizer-otp;
> 
> v2:
> To enable randomizer by checking chip options NAND_NO_SUBPAGE_WRITE
> 
> v1:
> To enable randomizer by sys-fs
> 
> Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
> ---
>  drivers/mtd/nand/raw/nand_macronix.c | 64 ++++++++++++++++++++++++++++++++++++

As long as you modify bindings, you should write a separate patch to
update the documentation and get it acked by Rob Herring.

>  1 file changed, 64 insertions(+)
> 
> diff --git a/drivers/mtd/nand/raw/nand_macronix.c b/drivers/mtd/nand/raw/nand_macronix.c
> index 58511ae..d5df09a 100644
> --- a/drivers/mtd/nand/raw/nand_macronix.c
> +++ b/drivers/mtd/nand/raw/nand_macronix.c
> @@ -11,6 +11,13 @@
>  #define MACRONIX_READ_RETRY_BIT BIT(0)
>  #define MACRONIX_NUM_READ_RETRY_MODES 6
>  
> +#define MACRONIX_RANDOMIZER_BIT BIT(1)
> +#define ONFI_FEATURE_ADDR_MXIC_RANDOMIZER 0xB0
> +#define MACRONIX_RANDOMIZER_ENPGM BIT(0)
> +#define MACRONIX_RANDOMIZER_RANDEN BIT(1)
> +#define MACRONIX_RANDOMIZER_RANDOPT BIT(2)
> +#define MACRONIX_RANDOMIZER_MODE_EXIT ~MACRONIX_RANDOMIZER_ENPGM

I would rather prefer a 

#define ...RANDOMISER_MODE_ENTER (ENGPM | RANDEN | RANDOPT)
#define ...RANDOMISER_MODE_EXIT (RANDEN | RANDOPT)

> +
>  struct nand_onfi_vendor_macronix {
>  	u8 reserved;
>  	u8 reliability_func;
> @@ -29,15 +36,72 @@ static int macronix_nand_setup_read_retry(struct nand_chip *chip, int mode)
>  	return nand_set_features(chip, ONFI_FEATURE_ADDR_READ_RETRY, feature);
>  }
>  
> +static void macronix_nand_randomizer_check_enable(struct nand_chip *chip)

You should return something and check it from the calling function.

> +{
> +	u8 feature[ONFI_SUBFEATURE_PARAM_LEN];
> +	int ret;
> +
> +	ret = nand_get_features(chip, ONFI_FEATURE_ADDR_MXIC_RANDOMIZER,
> +				feature);
> +	if (feature[0]) {
> +		pr_info("Macronix NAND randomizer enabled:0x%x\n", feature[0]);
> +		return;
> +	}
> +
> +	feature[0] = MACRONIX_RANDOMIZER_ENPGM | MACRONIX_RANDOMIZER_RANDEN |
> +		     MACRONIX_RANDOMIZER_RANDOPT;
> +	ret = nand_set_features(chip, ONFI_FEATURE_ADDR_MXIC_RANDOMIZER,
> +				feature);
> +	if (ret)
> +		goto err;
> +
> +	feature[0] = 0x0;
> +	ret = nand_prog_page_op(chip, 0, 0, feature, 1);

What is this? A comment is needed.

> +	if (ret)
> +		goto err;
> +
> +	ret = nand_get_features(chip, ONFI_FEATURE_ADDR_MXIC_RANDOMIZER,
> +				feature);
> +	if (ret)
> +		goto err;
> +
> +	feature[0] &= MACRONIX_RANDOMIZER_MODE_EXIT;
> +	ret = nand_set_features(chip, ONFI_FEATURE_ADDR_MXIC_RANDOMIZER,
> +				feature);
> +	if (ret)
> +		goto err;
> +
> +	pr_info("Macronix NAND randomizer enable ok\n");

The pr_info "ok" could be dropped, the "failed" one would go in
nand_onfi_init() after a check on the return code.

Then, no more goto's.

> +	return;
> +err:
> +	pr_err("Macronix NAND randomizer enable failed\n");
> +}
> +
>  static void macronix_nand_onfi_init(struct nand_chip *chip)
>  {
>  	struct nand_parameters *p = &chip->parameters;
>  	struct nand_onfi_vendor_macronix *mxic;
> +	struct device_node *dn = nand_get_flash_node(chip);
> +	int rand_otp = 0;
>  
>  	if (!p->onfi)
>  		return;
>  
> +	if (of_find_property(dn, "mxic,enable-randomizer-otp", NULL))
> +		rand_otp = 1;
> +
>  	mxic = (struct nand_onfi_vendor_macronix *)p->onfi->vendor;
> +	if (rand_otp && chip->options & NAND_NO_SUBPAGE_WRITE &&
> +	    mxic->reliability_func & MACRONIX_RANDOMIZER_BIT) {
> +		if (p->supports_set_get_features) {
> +			bitmap_set(p->set_feature_list,
> +				   ONFI_FEATURE_ADDR_MXIC_RANDOMIZER, 1);
> +			bitmap_set(p->get_feature_list,
> +				   ONFI_FEATURE_ADDR_MXIC_RANDOMIZER, 1);
> +			macronix_nand_randomizer_check_enable(chip);
> +		}
> +	}
> +
>  	if ((mxic->reliability_func & MACRONIX_READ_RETRY_BIT) == 0)
>  		return;
>  

Thanks,
Miquèl
Mason Yang Oct. 14, 2019, 9:27 a.m. UTC | #2
Hi Miquel,


> > changelog
> > v3:
> > To enable randomizer by specific DT property in children nodes,
> > mxic,enable-randomizer-otp;
> > 
> > v2:
> > To enable randomizer by checking chip options NAND_NO_SUBPAGE_WRITE
> > 
> > v1:
> > To enable randomizer by sys-fs
> > 
> > Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
> > ---
> >  drivers/mtd/nand/raw/nand_macronix.c | 64 
++++++++++++++++++++++++++++++++++++
> 
> As long as you modify bindings, you should write a separate patch to
> update the documentation and get it acked by Rob Herring.

Do you mean I have to create a new device tree binding file by 
nand_macronix.txt 
for raw NAND device ?

> 
> >  1 file changed, 64 insertions(+)
> > 
> > diff --git a/drivers/mtd/nand/raw/nand_macronix.c 
b/drivers/mtd/nand/raw/
> nand_macronix.c
> > index 58511ae..d5df09a 100644
> > --- a/drivers/mtd/nand/raw/nand_macronix.c
> > +++ b/drivers/mtd/nand/raw/nand_macronix.c
> > @@ -11,6 +11,13 @@
> >  #define MACRONIX_READ_RETRY_BIT BIT(0)
> >  #define MACRONIX_NUM_READ_RETRY_MODES 6
> > 
> > +#define MACRONIX_RANDOMIZER_BIT BIT(1)
> > +#define ONFI_FEATURE_ADDR_MXIC_RANDOMIZER 0xB0
> > +#define MACRONIX_RANDOMIZER_ENPGM BIT(0)
> > +#define MACRONIX_RANDOMIZER_RANDEN BIT(1)
> > +#define MACRONIX_RANDOMIZER_RANDOPT BIT(2)
> > +#define MACRONIX_RANDOMIZER_MODE_EXIT ~MACRONIX_RANDOMIZER_ENPGM
> 
> I would rather prefer a 
> 
> #define ...RANDOMISER_MODE_ENTER (ENGPM | RANDEN | RANDOPT)
> #define ...RANDOMISER_MODE_EXIT (RANDEN | RANDOPT)
> 

okay.

> > +
> >  struct nand_onfi_vendor_macronix {
> >     u8 reserved;
> >     u8 reliability_func;
> > @@ -29,15 +36,72 @@ static int macronix_nand_setup_read_retry(struct 
> nand_chip *chip, int mode)
> >     return nand_set_features(chip, ONFI_FEATURE_ADDR_READ_RETRY, 
feature);
> >  }
> > 
> > +static void macronix_nand_randomizer_check_enable(struct nand_chip 
*chip)
> 
> You should return something and check it from the calling function.

okay, will fix it.

> 
> > +{
> > +   u8 feature[ONFI_SUBFEATURE_PARAM_LEN];
> > +   int ret;
> > +
> > +   ret = nand_get_features(chip, ONFI_FEATURE_ADDR_MXIC_RANDOMIZER,
> > +            feature);
> > +   if (feature[0]) {
> > +      pr_info("Macronix NAND randomizer enabled:0x%x\n", feature[0]);
> > +      return;
> > +   }
> > +
> > +   feature[0] = MACRONIX_RANDOMIZER_ENPGM | 
MACRONIX_RANDOMIZER_RANDEN |
> > +           MACRONIX_RANDOMIZER_RANDOPT;
> > +   ret = nand_set_features(chip, ONFI_FEATURE_ADDR_MXIC_RANDOMIZER,
> > +            feature);
> > +   if (ret)
> > +      goto err;
> > +
> > +   feature[0] = 0x0;
> > +   ret = nand_prog_page_op(chip, 0, 0, feature, 1);
> 
> What is this? A comment is needed.

it's needed for a OTP bit programming flow.

> 
> > +   if (ret)
> > +      goto err;
> > +
> > +   ret = nand_get_features(chip, ONFI_FEATURE_ADDR_MXIC_RANDOMIZER,
> > +            feature);
> > +   if (ret)
> > +      goto err;
> > +
> > +   feature[0] &= MACRONIX_RANDOMIZER_MODE_EXIT;
> > +   ret = nand_set_features(chip, ONFI_FEATURE_ADDR_MXIC_RANDOMIZER,
> > +            feature);
> > +   if (ret)
> > +      goto err;
> > +
> > +   pr_info("Macronix NAND randomizer enable ok\n");
> 
> The pr_info "ok" could be dropped, the "failed" one would go in
> nand_onfi_init() after a check on the return code.
> 
> Then, no more goto's.

got it, will fix it.

thanks for your time and comments.

best regards,
Mason


CONFIDENTIALITY NOTE:

This e-mail and any attachments may contain confidential information 
and/or personal data, which is protected by applicable laws. Please be 
reminded that duplication, disclosure, distribution, or use of this e-mail 
(and/or its attachments) or any part thereof is prohibited. If you receive 
this e-mail in error, please notify us immediately and delete this mail as 
well as its attachment(s) from your system. In addition, please be 
informed that collection, processing, and/or use of personal data is 
prohibited unless expressly permitted by personal data protection laws. 
Thank you for your attention and cooperation.

Macronix International Co., Ltd.

=====================================================================



============================================================================

CONFIDENTIALITY NOTE:

This e-mail and any attachments may contain confidential information and/or personal data, which is protected by applicable laws. Please be reminded that duplication, disclosure, distribution, or use of this e-mail (and/or its attachments) or any part thereof is prohibited. If you receive this e-mail in error, please notify us immediately and delete this mail as well as its attachment(s) from your system. In addition, please be informed that collection, processing, and/or use of personal data is prohibited unless expressly permitted by personal data protection laws. Thank you for your attention and cooperation.

Macronix International Co., Ltd.

=====================================================================
diff mbox series

Patch

diff --git a/drivers/mtd/nand/raw/nand_macronix.c b/drivers/mtd/nand/raw/nand_macronix.c
index 58511ae..d5df09a 100644
--- a/drivers/mtd/nand/raw/nand_macronix.c
+++ b/drivers/mtd/nand/raw/nand_macronix.c
@@ -11,6 +11,13 @@ 
 #define MACRONIX_READ_RETRY_BIT BIT(0)
 #define MACRONIX_NUM_READ_RETRY_MODES 6
 
+#define MACRONIX_RANDOMIZER_BIT BIT(1)
+#define ONFI_FEATURE_ADDR_MXIC_RANDOMIZER 0xB0
+#define MACRONIX_RANDOMIZER_ENPGM BIT(0)
+#define MACRONIX_RANDOMIZER_RANDEN BIT(1)
+#define MACRONIX_RANDOMIZER_RANDOPT BIT(2)
+#define MACRONIX_RANDOMIZER_MODE_EXIT ~MACRONIX_RANDOMIZER_ENPGM
+
 struct nand_onfi_vendor_macronix {
 	u8 reserved;
 	u8 reliability_func;
@@ -29,15 +36,72 @@  static int macronix_nand_setup_read_retry(struct nand_chip *chip, int mode)
 	return nand_set_features(chip, ONFI_FEATURE_ADDR_READ_RETRY, feature);
 }
 
+static void macronix_nand_randomizer_check_enable(struct nand_chip *chip)
+{
+	u8 feature[ONFI_SUBFEATURE_PARAM_LEN];
+	int ret;
+
+	ret = nand_get_features(chip, ONFI_FEATURE_ADDR_MXIC_RANDOMIZER,
+				feature);
+	if (feature[0]) {
+		pr_info("Macronix NAND randomizer enabled:0x%x\n", feature[0]);
+		return;
+	}
+
+	feature[0] = MACRONIX_RANDOMIZER_ENPGM | MACRONIX_RANDOMIZER_RANDEN |
+		     MACRONIX_RANDOMIZER_RANDOPT;
+	ret = nand_set_features(chip, ONFI_FEATURE_ADDR_MXIC_RANDOMIZER,
+				feature);
+	if (ret)
+		goto err;
+
+	feature[0] = 0x0;
+	ret = nand_prog_page_op(chip, 0, 0, feature, 1);
+	if (ret)
+		goto err;
+
+	ret = nand_get_features(chip, ONFI_FEATURE_ADDR_MXIC_RANDOMIZER,
+				feature);
+	if (ret)
+		goto err;
+
+	feature[0] &= MACRONIX_RANDOMIZER_MODE_EXIT;
+	ret = nand_set_features(chip, ONFI_FEATURE_ADDR_MXIC_RANDOMIZER,
+				feature);
+	if (ret)
+		goto err;
+
+	pr_info("Macronix NAND randomizer enable ok\n");
+	return;
+err:
+	pr_err("Macronix NAND randomizer enable failed\n");
+}
+
 static void macronix_nand_onfi_init(struct nand_chip *chip)
 {
 	struct nand_parameters *p = &chip->parameters;
 	struct nand_onfi_vendor_macronix *mxic;
+	struct device_node *dn = nand_get_flash_node(chip);
+	int rand_otp = 0;
 
 	if (!p->onfi)
 		return;
 
+	if (of_find_property(dn, "mxic,enable-randomizer-otp", NULL))
+		rand_otp = 1;
+
 	mxic = (struct nand_onfi_vendor_macronix *)p->onfi->vendor;
+	if (rand_otp && chip->options & NAND_NO_SUBPAGE_WRITE &&
+	    mxic->reliability_func & MACRONIX_RANDOMIZER_BIT) {
+		if (p->supports_set_get_features) {
+			bitmap_set(p->set_feature_list,
+				   ONFI_FEATURE_ADDR_MXIC_RANDOMIZER, 1);
+			bitmap_set(p->get_feature_list,
+				   ONFI_FEATURE_ADDR_MXIC_RANDOMIZER, 1);
+			macronix_nand_randomizer_check_enable(chip);
+		}
+	}
+
 	if ((mxic->reliability_func & MACRONIX_READ_RETRY_BIT) == 0)
 		return;