NAND: add support for reading ONFI parameters from NAND device

(quoted diff) +13 -0

+/*
+ * sanitize ONFI strings so we can safely print them
+ */
+static void sanitize_string(uint8_t *s, size_t len)
+{
+	ssize_t i;
+
+	/* null terminate */
+	s[len - 1] = 0;
+
+	/* remove non printable chars */
+	for (i = 0; i<  len - 1; i++) {
+		if (s[i]<  ' ' || s[i]>  127)

(quoted diff) +4 -6

@@ -2811,7 +2846,7 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
 
  	/* Read manufacturer and device IDs */
  	*maf_id = chip->read_byte(mtd);
-	dev_id = chip->read_byte(mtd);
+	*dev_id = chip->read_byte(mtd);
 
  	/* Try again to make sure, as some systems the bus-hold or other
  	 * interface concerns can cause random data which looks like a

@@ -2821,15 +2856,13 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
 
  	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
 
-	/* Read entire ID string */
-
-	for (i = 0; i<  8; i++)
+	for (i = 0; i<  2; i++)
  		id_data[i] = chip->read_byte(mtd);
 
-	if (id_data[0] != *maf_id || id_data[1] != dev_id) {
+	if (id_data[0] != *maf_id || id_data[1] != *dev_id) {
  		printk(KERN_INFO "%s: second ID read did not match "
  		       "%02x,%02x against %02x,%02x\n", __func__,
-		       *maf_id, dev_id, id_data[0], id_data[1]);
+		       *maf_id, *dev_id, id_data[0], id_data[1]);
  		return ERR_PTR(-ENODEV);
  	}
 

(quoted diff) +1 -0

+	if (!is_power_of_2(val) || val == 1 || val > (1 << 4)) {

the !is_power_of_2 check does not work for ONFI version 2.1 (3), so I would only keep the two other checks."

Hello,

I've got a few comments and a patch; I cannot test them, though, just build.

On 08/12/2010 05:53 AM, Florian Fainelli wrote:

drivers/mtd/nand/nand_base.c static void nand_set_defaults(struct nand_chip *chip, int busw) · line 2799

Quoted 10 lines

drivers/mtd/nand/nand_base.c +10 -0

+static u16 onfi_crc(u16 crc, unsigned char const *p, size_t len)
+{
+	int i;
+	while (len--) {
+		crc ^= *p++<<  8;
+		for (i = 0; i<  8; i++)
+			crc = (crc<<  1) ^ ((crc&  0x8000) ? 0x8005 : 0);
+	}
+	return crc;
+}

Can this function safely be replaced by the library function crc16? #include <linux/crc16.h>
u16 crc16(u16 crc, u8 const *buffer, size_t len);

Quoted 20 lines

drivers/mtd/nand/nand_base.c +19 -0

+/*
+ * sanitize ONFI strings so we can safely print them
+ */
+static void sanitize_string(uint8_t *s, size_t len)
+{
+	ssize_t i;
+
+	/* null terminate */
+	s[len - 1] = 0;
+
+	/* remove non printable chars */
+	for (i = 0; i<  len - 1; i++) {
+		if (s[i]<  ' ' || s[i]>  127)
+			s[i] = '?';
+	}
+
+	/* remove trailing spaces */
+	for (i = len - 1; i>= 0; i--) {
+		if (s[i]&&  s[i] != ' ')

drivers/mtd/nand/nand_base.c static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd, · line 2897

Quoted 4 lines

drivers/mtd/nand/nand_base.c +4 -0

+			break;
+		s[i] = 0;
+	}
+}

And the "remove trailing spaces" can be accomplished via strim. #include <linux/string.h>
char *strim(char *);

Quoted 39 lines

drivers/mtd/nand/nand_base.c +1 -1

@@ -2811,7 +2846,7 @@ static struct nand_flash_dev
 *nand_get_flash_type(struct mtd_info *mtd,
 
  	/* Read manufacturer and device IDs */
  	*maf_id = chip->read_byte(mtd);
 
-	dev_id = chip->read_byte(mtd);
+	*dev_id = chip->read_byte(mtd);
 

/* Try again to make sure, as some systems the bus-hold or other

* interface concerns can cause random data which looks like a

(quoted diff) +3 -5

@@ -2821,15 +2856,13 @@ static struct nand_flash_dev
 *nand_get_flash_type(struct mtd_info *mtd,
 
  	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
 
-	/* Read entire ID string */
-
-	for (i = 0; i<  8; i++)
+	for (i = 0; i<  2; i++)
 
  		id_data[i] = chip->read_byte(mtd);
 
-	if (id_data[0] != *maf_id || id_data[1] != dev_id) {
+	if (id_data[0] != *maf_id || id_data[1] != *dev_id) {
 
  		printk(KERN_INFO "%s: second ID read did not match "
 
  		       "%02x,%02x against %02x,%02x\n", __func__,
 
-		       *maf_id, dev_id, id_data[0], id_data[1]);
+		       *maf_id, *dev_id, id_data[0], id_data[1]);
 
  		return ERR_PTR(-ENODEV);
 
  	}

<snip>

drivers/mtd/nand/nand_base.c static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd, · line 2940

Quoted 12 lines

drivers/mtd/nand/nand_base.c +8 -0

+
+	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
+
+	/* Read entire ID string */
+
+	for (i = 0; i<  8; i++)
+		id_data[i] = chip->read_byte(mtd);
+
 
  	if (!type->name)
 
  		return ERR_PTR(-ENODEV);

Do we really need a third chance to read the ID bytes? It seems like we can just read the whole string the second time instead of shortening it to two bytes and waiting to reread all 8 bytes until after the ONFI scan.

Review

Quoted 8 lines

(quoted diff) +8 -0

+					if (val&  (1<<  1))
+						chip->onfi_version = 10;
+					else if (val&  (1<<  2))
+						chip->onfi_version = 20;
+					else if (val&  (1<<  3))
+						chip->onfi_version = 21;
+					else
+						chip->onfi_version = 22;

I cannot currently test ONFI on a real chip, but shouldn't the order of these conditionals be switched? It seems possible that the bits could be set high for more the one version (e.g., a chip supports 1.0 and 2.0, so we have val = 00000110 (binary), so the current logic would succeed at 1.0, not realizing that it supports 2.0. Again, I don't know about the actual behavior in a real chip, but anyway, it seems harmless to reverse this.

Quoted 3 lines · you

(quoted diff) +1 -0

+	if (!is_power_of_2(val) || val == 1 || val > (1 << 4)) {

the !is_power_of_2 check does not work for ONFI version 2.1 (3), so I would only keep the two other checks."

So why is it now:

Review

Quoted 1 line

(quoted diff) +1 -0

+	if (is_power_of_2(val) || val == 1 || val > (1 << 4)) {

Is that a typo? Perhaps it's better to throw that test out altogether.

I "fixed" the changes I mentioned as well as a few coding style, logic cleanups, etc. (e.g. too many levels of logic, creating lines > 80 chars). Here's a new patch. I didn't change over the crc function to the library function because that would require configuring the Kbuild options and setting a dependency, which I'm not familiar with. I'm certainly not an expert on most of this, so take my patch with a grain of salt!

Brian

Note: I didn't know what to do on the "Signed-off" when I have edited someone else's patch. Include mine if you'd like:

Signed-off-by Brian Norris <[email protected]>

-------------------------------------------------------------------------

This patch adds support for reading NAND device ONFI parameters and use the ONFI informations to define its geometry. In case the device supports ONFI, the onfi_version field in struct nand_chip contains the version (BCD) and the onfi_params structure can be used by drivers to set up timings and such. We currently only support ONFI 1.0 parameters.

---
 drivers/mtd/nand/nand_base.c |  158
++++++++++++++++++++++++++++++++++-------- include/linux/mtd/nand.h     | 
 66 +++++++++++++++++
 2 files changed, 194 insertions(+), 30 deletions(-)

drivers/mtd/nand/nand_base.c +34 -1

index a3c7473..b6d6121 100644
@@ -33,6 +33,7 @@
  */
 
 #include <linux/module.h>
+#include <linux/crc16.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/err.h>

@@ -2786,15 +2787,47 @@ static void nand_set_defaults(struct nand_chip
 *chip, int busw)
 
 }
 
+static u16 onfi_crc(u16 crc, unsigned char const *p, size_t len)
+{
+	int i;
+	while (len--) {
+		crc ^= *p++ << 8;
+		for (i = 0; i < 8; i++)
+			crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
+	}
+	return crc;
+}
+
+/*
+ * sanitize ONFI strings so we can safely print them
+ */
+static void sanitize_string(uint8_t *s, size_t len)
+{
+	ssize_t i;
+
+	/* null terminate */
+	s[len - 1] = '\0';
+
+	/* remove non-printable chars */
+	for (i = 0; i < len - 1; i++) {
+		if (s[i] < ' ' || s[i] > 127)
+			s[i] = '?';
+	}
+
+	/* remove trailing spaces */
+	strim(s);
+}
+
 /*
  * Get the flash and manufacturer id and lookup if the type is supported
  */
 static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
 						  struct nand_chip *chip,
 						  int busw, int *maf_id,
+						  int *dev_id,
 						  struct nand_flash_dev *type)
 {
-	int i, dev_id, maf_idx;
+	int i, maf_idx;
 	u8 id_data[8];
 

drivers/mtd/nand/nand_base.c +1 -1

 	/* Select the device */

@@ -2811,7 +2844,7 @@ static struct nand_flash_dev
 *nand_get_flash_type(struct mtd_info *mtd,
 
 	/* Read manufacturer and device IDs */
 	*maf_id = chip->read_byte(mtd);
-	dev_id = chip->read_byte(mtd);
+	*dev_id = chip->read_byte(mtd);
 
 	/* Try again to make sure, as some systems the bus-hold or other

drivers/mtd/nand/nand_base.c +83 -5

 	 * interface concerns can cause random data which looks like a

@@ -2822,14 +2855,13 @@ static struct nand_flash_dev
 *nand_get_flash_type(struct mtd_info *mtd, chip->cmdfunc(mtd,
 NAND_CMD_READID, 0x00, -1);
 
 	/* Read entire ID string */
-
 	for (i = 0; i < 8; i++)
 		id_data[i] = chip->read_byte(mtd);
 
-	if (id_data[0] != *maf_id || id_data[1] != dev_id) {
+	if (id_data[0] != *maf_id || id_data[1] != *dev_id) {
 		printk(KERN_INFO "%s: second ID read did not match "
 		       "%02x,%02x against %02x,%02x\n", __func__,
-		       *maf_id, dev_id, id_data[0], id_data[1]);
+		       *maf_id, *dev_id, id_data[0], id_data[1]);
 		return ERR_PTR(-ENODEV);
 	}

@@ -2837,8 +2869,72 @@ static struct nand_flash_dev
 *nand_get_flash_type(struct mtd_info *mtd, type = nand_flash_ids;
 
 	for (; type->name != NULL; type++)
-		if (dev_id == type->id)
-                        break;
+		if (*dev_id == type->id)
+			break;
+
+	chip->onfi_version = 0;
+	/* try ONFI for unknown or large page size chips */
+	if (!type->name || !type->pagesize) {
+		struct nand_onfi_params *p = &chip->onfi_params;
+		int i, val;
+
+		chip->cmdfunc(mtd, NAND_CMD_READID, 0x20, -1);
+		if (chip->read_byte(mtd) == 'O' &&
+			chip->read_byte(mtd) == 'N' &&
+			chip->read_byte(mtd) == 'F' &&
+			chip->read_byte(mtd) == 'I') {
+
+			printk(KERN_INFO "ONFI flash detected\n");
+			chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
+			for (i = 0; i < 3; i++) {
+				chip->read_buf(mtd, (uint8_t *)p, sizeof(*p));
+				if (onfi_crc(0x4F4E, (uint8_t *)p, 254) ==
+						le16_to_cpu(p->crc)) {
+					printk(KERN_INFO "ONFI param page %d"
+						       "valid\n", i);
+					break;
+				}
+			}
+
+			/* check version */
+			val = (i < 3) ? le16_to_cpu(p->revision) : 0;
+			if (val & (4 << 1))
+				chip->onfi_version = 22;
+			else if (val & (1 << 3))
+				chip->onfi_version = 21;
+			else if (val & (1 << 2))
+				chip->onfi_version = 20;
+			else if (val & (1 << 1))
+				chip->onfi_version = 10;
+			else
+				printk(KERN_INFO "%s: unsupported ONFI version:"
+						" %d\n", __func__, val);
+			if (chip->onfi_version) {
+				sanitize_string(p->manufacturer,
+						sizeof(p->manufacturer));
+				sanitize_string(p->model, sizeof(p->model));
+				if (!mtd->name)
+					mtd->name = p->model;
+				mtd->writesize = le32_to_cpu(p->byte_per_page);
+				mtd->erasesize = le32_to_cpu(p->pages_per_block)
+					* mtd->writesize;
+				mtd->oobsize = le16_to_cpu(
+						p->spare_bytes_per_page);
+				chip->chipsize = le32_to_cpu(p->blocks_per_lun)
+					* mtd->erasesize;
+				busw = 0;
+				if (le16_to_cpu(p->features) & 1)
+					busw = NAND_BUSWIDTH_16;
+
+				chip->options &= ~NAND_CHIPOPTIONS_MSK;
+				chip->options |= (NAND_NO_READRDY |
+						NAND_NO_AUTOINCR)
+					& NAND_CHIPOPTIONS_MSK;
+
+				goto ident_done;
+			}
+		}
+	}
 
 	if (!type->name)
 		return ERR_PTR(-ENODEV);

@@ -2900,6 +2996,21 @@ static struct nand_flash_dev
 *nand_get_flash_type(struct mtd_info *mtd, mtd->oobsize = mtd->writesize /
 32;
 		busw = type->options & NAND_BUSWIDTH_16;
 	}
+	/* Get chip options, preserve non chip based options */
+	chip->options &= ~NAND_CHIPOPTIONS_MSK;
+	chip->options |= type->options & NAND_CHIPOPTIONS_MSK;
+
+	/* Check if chip is a not a samsung device. Do not clear the
+	 * options for chips which are not having an extended id.
+	 */
+	if (*maf_id != NAND_MFR_SAMSUNG && !type->pagesize)
+		chip->options &= ~NAND_SAMSUNG_LP_OPTIONS;
+ident_done:
+
+	/*
+	 * Set chip as a default. Board drivers can override it, if necessary
+	 */
+	chip->options |= NAND_NO_AUTOINCR;
 
 	/* Try to identify manufacturer */

drivers/mtd/nand/nand_base.c +3 -18

 	for (maf_idx = 0; nand_manuf_ids[maf_idx].id != 0x0; maf_idx++) {

@@ -2914,10 +3025,10 @@ static struct nand_flash_dev
 *nand_get_flash_type(struct mtd_info *mtd, if (busw != (chip->options &
 NAND_BUSWIDTH_16)) {
 		printk(KERN_INFO "NAND device: Manufacturer ID:"
 		       " 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id,
-		       dev_id, nand_manuf_ids[maf_idx].name, mtd->name);
+		       *dev_id, nand_manuf_ids[maf_idx].name, mtd->name);
 		printk(KERN_WARNING "NAND bus width %d instead %d bit\n",
-		       (chip->options & NAND_BUSWIDTH_16) ? 16 : 8,
-		       busw ? 16 : 8);
+				(chip->options & NAND_BUSWIDTH_16) ? 16 : 8,
+				busw ? 16 : 8);
 		return ERR_PTR(-EINVAL);
 	}

@@ -2943,21 +3054,6 @@ static struct nand_flash_dev
 *nand_get_flash_type(struct mtd_info *mtd, chip->badblockpos =
 NAND_LARGE_BADBLOCK_POS;
 
 
-	/* Get chip options, preserve non chip based options */
-	chip->options &= ~NAND_CHIPOPTIONS_MSK;
-	chip->options |= type->options & NAND_CHIPOPTIONS_MSK;
-
-	/*
-	 * Set chip as a default. Board drivers can override it, if necessary
-	 */
-	chip->options |= NAND_NO_AUTOINCR;
-
-	/* Check if chip is a not a samsung device. Do not clear the
-	 * options for chips which are not having an extended id.
-	 */
-	if (*maf_id != NAND_MFR_SAMSUNG && !type->pagesize)
-		chip->options &= ~NAND_SAMSUNG_LP_OPTIONS;
-
 	/*
 	 * Bad block marker is stored in the last page of each block

drivers/mtd/nand/nand_base.c +4 -2

 	 * on Samsung and Hynix MLC devices; stored in first two pages

@@ -2997,9 +3093,11 @@ static struct nand_flash_dev
 *nand_get_flash_type(struct mtd_info *mtd, if (mtd->writesize > 512 &&
 chip->cmdfunc == nand_command)
 		chip->cmdfunc = nand_command_lp;
 
+	/* TODO onfi flash name */
 	printk(KERN_INFO "NAND device: Manufacturer ID:"
-	       " 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id, dev_id,
-	       nand_manuf_ids[maf_idx].name, type->name);
+		" 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id, *dev_id,
+		nand_manuf_ids[maf_idx].name,
+		chip->onfi_version ? type->name:chip->onfi_params.model);
 
 	return type;

}

drivers/mtd/nand/nand_base.c +2 -2

@@ -3018,7 +3116,7 @@ static struct nand_flash_dev
 *nand_get_flash_type(struct mtd_info *mtd, int nand_scan_ident(struct
 mtd_info *mtd, int maxchips,
 		    struct nand_flash_dev *table)
 {
-	int i, busw, nand_maf_id;
+	int i, busw, nand_maf_id, nand_dev_id;
 	struct nand_chip *chip = mtd->priv;
 	struct nand_flash_dev *type;

@@ -3028,7 +3126,7 @@ int nand_scan_ident(struct mtd_info *mtd, int
 maxchips, nand_set_defaults(chip, busw);
 
 	/* Read the flash type */
-	type = nand_get_flash_type(mtd, chip, busw, &nand_maf_id, table);
+	type = nand_get_flash_type(mtd, chip, busw, &nand_maf_id, &nand_dev_id,
 table);
 
 	if (IS_ERR(type)) {

drivers/mtd/nand/nand_base.c +1 -1

 		if (!(chip->options & NAND_SCAN_SILENT_NODEV))

@@ -3046,7 +3144,7 @@ int nand_scan_ident(struct mtd_info *mtd, int
 maxchips, chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
 		/* Read manufacturer and device IDs */
 		if (nand_maf_id != chip->read_byte(mtd) ||
-		    type->id != chip->read_byte(mtd))
+		    nand_dev_id != chip->read_byte(mtd))
 			break;
 	}
 	if (i > 1)

include/linux/mtd/nand.h +61 -0

index 8b288b6..135576f 100644
@@ -228,6 +228,67 @@ typedef enum {
 /* Keep gcc happy */
 struct nand_chip;
 
+struct nand_onfi_params {
+	/* rev info and features block */
+	u8		sig[4]; /* 'O' 'N' 'F' 'I'  */
+	__le16		revision;
+	__le16		features;
+	__le16		opt_cmd;
+	u8		reserved[22];
+
+	/* manufacturer information block */
+	char		manufacturer[12];
+	char		model[20];
+	u8		jedec_id;
+	__le16		date_code;
+	u8		reserved2[13];
+
+	/* memory organization block */
+	__le32		byte_per_page;
+	__le16		spare_bytes_per_page;
+	__le32		data_bytes_per_ppage;
+	__le16		sparre_bytes_per_ppage;
+	__le32		pages_per_block;
+	__le32		blocks_per_lun;
+	u8		lun_count;
+	u8		addr_cycles;
+	u8		bits_per_cell;
+	__le16		bb_per_lun;
+	__le16		block_endurance;
+	u8		guaranteed_good_blocks;
+	__le16		guaranteed_block_endurance;
+	u8		programs_per_page;
+	u8		ppage_attr;
+	u8		ecc_bits;
+	u8		interleaved_bits;
+	u8		interleaved_ops;
+	u8		reserved3[13];
+
+	/* electrical parameter block */
+	u8		io_pin_capacitance_max;
+	__le16		async_timing_mode;
+	__le16		program_cache_timing_mode;
+	__le16		t_prog;
+	__le16		t_bers;
+	__le16		t_r;
+	__le16		t_ccs;
+	__le16		src_sync_timing_mode;
+	__le16		src_ssync_features;
+	__le16		clk_pin_capacitance_typ;
+	__le16		io_pin_capacitance_typ;
+	__le16		input_pin_capacitance_typ;
+	u8		input_pin_capacitance_max;
+	u8		driver_strenght_support;
+	__le16		t_int_r;
+	__le16		t_ald;
+	u8		reserved4[7];
+
+	/* vendor */
+	u8		reserved5[90];
+
+	__le16 crc;
+} __attribute__((packed));
+
 /**
  * struct nand_hw_control - Control structure for hardware controller (e.g

ECC generator) shared among independent devices * @lock:
protection lock

include/linux/mtd/nand.h +1 -0

@@ -360,6 +421,8 @@ struct nand_buffers {
  * @pagemask:		[INTERN] page number mask = number of (pages / chip) - 1
  * @pagebuf:		[INTERN] holds the pagenumber which is currently in data_buf
  * @subpagesize:	[INTERN] holds the subpagesize
+ * @onfi_version:	[INTERN] holds the chip ONFI version (BCD encoded), non

0 if ONFI supported + * @onfi_params: [INTERN] holds the ONFI page
parameter when ONFI is supported, 0 otherwise * @ecclayout: [REPLACEABLE]
the default ecc placement scheme
* @bbt: [INTERN] bad block table pointer
* @bbt_td: [REPLACEABLE] bad block table descriptor for flash lookup

include/linux/mtd/nand.h +3 -0

@@ -412,6 +475,9 @@ struct nand_chip {
 	int		badblockpos;
 	int		badblockbits;
 
+	int		onfi_version;
+	struct nand_onfi_params	onfi_params;
+
 	flstate_t	state;
 
 	uint8_t		*oob_poi;

Quoted 5 lines

Quoted 3 lines · you

+ if (!is_power_of_2(val) || val == 1 || val > (1 << 4)) {
the !is_power_of_2 check does not work for ONFI version 2.1 (3), so I would only keep the two other checks."

Quoted 4 lines

So why is it now:

Quoted 1 line

+ if (is_power_of_2(val) || val == 1 || val > (1 << 4)) {

Is that a typo? Perhaps it's better to throw that test out altogether.

That was not a typo, I actually misread the ONFI specification and confused bit is set, with the actual value. So this is the correct check, sorry about that.

Quoted 6 lines

I "fixed" the changes I mentioned as well as a few coding style, logic cleanups, etc. (e.g. too many levels of logic, creating lines > 80 chars). Here's a new patch. I didn't change over the crc function to the library function because that would require configuring the Kbuild options and setting a dependency, which I'm not familiar with. I'm certainly not an expert on most of this, so take my patch with a grain of salt!

It is usually as simple as doing the proper select FOO in the related Kconfig.

Hi,

Quoted 13 lines · Florian Fainelli

Quoted 9 lines

Quoted 3 lines · you

+ if (!is_power_of_2(val) || val == 1 || val > (1 << 4)) {
the !is_power_of_2 check does not work for ONFI version 2.1 (3), so I would only keep the two other checks."

So why is it now:

Quoted 1 line

+ if (is_power_of_2(val) || val == 1 || val > (1 << 4)) {

Is that a typo? Perhaps it's better to throw that test out altogether.

That was not a typo, I actually misread the ONFI specification and confused bit is set, with the actual value. So this is the correct check, sorry about that.

Again, I might be mistaken, but it seems that the "is_power_of_2" would weed out ONFI 1.0, since val would be simply 1 << 1, i.e., val == 2. Really, it seems that the ONFI version number may or may not be a power of two. If so, then we should just check individual bits as performed in the other tests (and perhaps include a test to be sure "val & 1 == 0")

Quoted 9 lines

Quoted 8 lines

I "fixed" the changes I mentioned as well as a few coding style, logic cleanups, etc. (e.g. too many levels of logic, creating lines > 80 chars). Here's a new patch. I didn't change over the crc function to the library function because that would require configuring the Kbuild options and setting a dependency, which I'm not familiar with. I'm certainly not an expert on most of this, so take my patch with a grain of salt!

Quoted 2 lines

It is usually as simple as doing the proper select FOO in the related Kconfig.

Thanks for the tip. It worked for me.

Hello Brian,

Quoted 6 lines · Brian Norris

Hello,

I've got a few comments and a patch; I cannot test them, though, just build.

On 08/12/2010 05:53 AM, Florian Fainelli wrote:

Quoted 13 lines

drivers/mtd/nand/nand_base.c static void nand_set_defaults(struct nand_chip *chip, int busw) · line 2799

Quoted 10 lines

drivers/mtd/nand/nand_base.c +10 -0

+static u16 onfi_crc(u16 crc, unsigned char const *p, size_t len)
+{
+   int i;
+   while (len--) {
+           crc ^= *p++<<  8;
+           for (i = 0; i<  8; i++)
+                   crc = (crc<<  1) ^ ((crc&  0x8000) ? 0x8005 : 0);
+   }
+   return crc;
+}

Can this function safely be replaced by the library function crc16? #include <linux/crc16.h>
u16 crc16(u16 crc, u8 const *buffer, size_t len);

Certainly, thanks for noticing.

Quoted 10 lines

Quoted 10 lines

drivers/mtd/nand/nand_base.c +8 -0

+
+   chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
+
+   /* Read entire ID string */
+
+   for (i = 0; i<  8; i++)
+           id_data[i] = chip->read_byte(mtd);
+

Quoted 6 lines

Quoted 3 lines

    if (!type->name)

            return ERR_PTR(-ENODEV);

Do we really need a third chance to read the ID bytes? It seems like we can just read the whole string the second time instead of shortening it to two bytes and waiting to reread all 8 bytes until after the ONFI scan.

Quoted 9 lines

Review

Quoted 9 lines

(quoted diff) +8 -0

+                                   if (val&  (1<<  1))
+                                           chip->onfi_version = 10;
+                                   else if (val&  (1<<  2))
+                                           chip->onfi_version = 20;
+                                   else if (val&  (1<<  3))
+                                           chip->onfi_version = 21;
+                                   else
+                                           chip->onfi_version = 22;

Quoted 6 lines

I cannot currently test ONFI on a real chip, but shouldn't the order of these conditionals be switched? It seems possible that the bits could be set high for more the one version (e.g., a chip supports 1.0 and 2.0, so we have val = 00000110 (binary), so the current logic would succeed at 1.0, not realizing that it supports 2.0. Again, I don't know about the actual behavior in a real chip, but anyway, it seems harmless to reverse this.

I think you are right about this. We only have ONFI 1.0 compliant chips right now, so we can't know for sure, but as you say, this is harmless.

Hello,

Quoted 24 lines · Florian Fainelli

Hello Brian,

Quoted 20 lines · Brian Norris

Hello,

I've got a few comments and a patch; I cannot test them, though, just build.

drivers/mtd/nand/nand_base.c static void nand_set_defaults(struct nand_chip *chip, int busw) · line 2799

Quoted 10 lines · Florian Fainelli

drivers/mtd/nand/nand_base.c +10 -0

+static u16 onfi_crc(u16 crc, unsigned char const *p, size_t len)
+{
+   int i;
+   while (len--) {
+           crc ^= *p++<<  8;
+           for (i = 0; i<  8; i++)
+                   crc = (crc<<  1) ^ ((crc&  0x8000) ? 0x8005 : 0);
+   }
+   return crc;
+}

Can this function safely be replaced by the library function crc16? #include <linux/crc16.h>
u16 crc16(u16 crc, u8 const *buffer, size_t len);

Quoted 1 line

Certainly, thanks for noticing.

No it is not the same crc16 endianness, one is big the other is little.

Quoted 10 lines

Quoted 10 lines

Quoted 10 lines

drivers/mtd/nand/nand_base.c +8 -0

+
+   chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
+
+   /* Read entire ID string */
+
+   for (i = 0; i<  8; i++)
+           id_data[i] = chip->read_byte(mtd);
+

Quoted 8 lines

Quoted 8 lines

Quoted 3 lines

    if (!type->name)
    
            return ERR_PTR(-ENODEV);

Do we really need a third chance to read the ID bytes? It seems like we can just read the whole string the second time instead of shortening it to two bytes and waiting to reread all 8 bytes until after the ONFI scan.

Well onfi define only 2 bytes for id string, I though it was safer to not read beyond specification for onfi nand.

Quoted 17 lines

Quoted 9 lines

Review

Quoted 8 lines

(quoted diff) +8 -0

+                                   if (val&  (1<<  1))
+                                           chip->onfi_version = 10;
+                                   else if (val&  (1<<  2))
+                                           chip->onfi_version = 20;
+                                   else if (val&  (1<<  3))
+                                           chip->onfi_version = 21;
+                                   else
+                                           chip->onfi_version = 22;

Quoted 7 lines

I cannot currently test ONFI on a real chip, but shouldn't the order of these conditionals be switched? It seems possible that the bits could be set high for more the one version (e.g., a chip supports 1.0 and 2.0, so we have val = 00000110 (binary), so the current logic would succeed at 1.0, not realizing that it supports 2.0. Again, I don't know about the actual behavior in a real chip, but anyway, it seems harmless to reverse this.

Quoted 2 lines

I think you are right about this. We only have ONFI 1.0 compliant chips right now, so we can't know for sure, but as you say, this is harmless.

ok

Matthieu

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