Message ID | 1362415655-13073-1-git-send-email-u.kleine-koenig@pengutronix.de |
---|---|
State | Changes Requested |
Headers | show |
Hello, I forgot to add Huang Shijie to Cc: and copied the wrong Message-Id for the --in-reply-to parameter to git-send-email. @Huang Shijie: I didn't carry over your Ack to this new patch. Are you still happy with this one? Sorry, Uwe On Mon, Mar 04, 2013 at 05:47:35PM +0100, Uwe Kleine-König wrote: > According to the Open NAND Flash Interface Specification (ONFI) Revision > 3.1 "Parameters are always transferred on the lower 8-bits of the data > bus." for the Get Features and Set Features commands. > > So using read_buf and write_buf is wrong for 16-bit wide nand chips as > they use I/O[15:0]. The Get Features command is easily fixed using 4 > times the read_byte callback. For Set Features implement a new > overwritable callback "write_byte". Still I expect the default to work > just fine for all controllers. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > > Notes: > v1 got an > Acked-by: Huang Shijie <b32955@freescale.com> > > Changes since (implicit) v1, sent with > Message-Id:1361977852-18233-1-git-send-email-u.kleine-koenig@pengutronix.de: > > - implement a new write_byte callback to also fix > nand_onfi_set_features (instead of returning -ENOSUPP in v1) > > drivers/mtd/nand/nand_base.c | 60 +++++++++++++++++++++++++++++++++++++++++--- > include/linux/mtd/nand.h | 3 +++ > 2 files changed, 59 insertions(+), 4 deletions(-) > > diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c > index 3766682..956b499 100644 > --- a/drivers/mtd/nand/nand_base.c > +++ b/drivers/mtd/nand/nand_base.c > @@ -205,6 +205,50 @@ static void nand_select_chip(struct mtd_info *mtd, int chipnr) > } > > /** > + * nand_write_byte - [DEFAULT] write single byte to chip > + * @mtd: MTD device structure > + * @byte: value to write > + * > + * Default function to write a byte to I/O[7:0] > + */ > +static void nand_write_byte(struct mtd_info *mtd, uint8_t byte) > +{ > + struct nand_chip *chip = mtd->priv; > + > + chip->write_buf(mtd, &byte, 1); > +} > + > +/** > + * nand_write_byte16 - [DEFAULT] write single byte to a chip with width 16 > + * @mtd: MTD device structure > + * @byte: value to write > + * > + * Default function to write a byte to I/O[7:0] on a 16-bit wide chip. > + */ > +static void nand_write_byte16(struct mtd_info *mtd, uint8_t byte) > +{ > + struct nand_chip *chip = mtd->priv; > + > + /* > + * It's not entirely clear what should happen to I/O[15:8] when writing > + * a byte. The ONFi spec (Revision 3.1; 2012-09-19, Section 2.16) reads: > + * > + * When the host supports a 16-bit bus width, only data is > + * transferred at the 16-bit width. All address and command line > + * transfers shall use only the lower 8-bits of the data bus. During > + * command transfers, the host may place any value on the upper > + * 8-bits of the data bus. During address transfers, the host shall > + * set the upper 8-bits of the data bus to 00h. > + * > + * One user of the write_byte callback is nand_onfi_set_features. The > + * four parameters are specified to be written to I/O[7:0], but this is > + * neither an address nor a command transfer. Let's assume a 0 on the > + * upper I/O lines is OK. > + */ > + chip->write_buf(mtd, (uint8_t[]){ byte, 0 }, 2); > +} > + > +/** > * nand_write_buf - [DEFAULT] write buffer to chip > * @mtd: MTD device structure > * @buf: data buffer > @@ -2710,7 +2754,7 @@ static int nand_block_markbad(struct mtd_info *mtd, loff_t ofs) > } > > /** > - * nand_onfi_set_features- [REPLACEABLE] set features for ONFI nand > + * nand_onfi_set_features - [REPLACEABLE] set features for ONFI nand > * @mtd: MTD device structure > * @chip: nand chip info structure > * @addr: feature address. > @@ -2720,12 +2764,15 @@ static int nand_onfi_set_features(struct mtd_info *mtd, struct nand_chip *chip, > int addr, uint8_t *subfeature_param) > { > int status; > + int i; > > if (!chip->onfi_version) > return -EINVAL; > > chip->cmdfunc(mtd, NAND_CMD_SET_FEATURES, addr, -1); > - chip->write_buf(mtd, subfeature_param, ONFI_SUBFEATURE_PARAM_LEN); > + for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i) > + chip->write_byte(mtd, subfeature_param[i]); > + > status = chip->waitfunc(mtd, chip); > if (status & NAND_STATUS_FAIL) > return -EIO; > @@ -2733,7 +2780,7 @@ static int nand_onfi_set_features(struct mtd_info *mtd, struct nand_chip *chip, > } > > /** > - * nand_onfi_get_features- [REPLACEABLE] get features for ONFI nand > + * nand_onfi_get_features - [REPLACEABLE] get features for ONFI nand > * @mtd: MTD device structure > * @chip: nand chip info structure > * @addr: feature address. > @@ -2742,6 +2789,8 @@ static int nand_onfi_set_features(struct mtd_info *mtd, struct nand_chip *chip, > static int nand_onfi_get_features(struct mtd_info *mtd, struct nand_chip *chip, > int addr, uint8_t *subfeature_param) > { > + int i; > + > if (!chip->onfi_version) > return -EINVAL; > > @@ -2749,7 +2798,8 @@ static int nand_onfi_get_features(struct mtd_info *mtd, struct nand_chip *chip, > memset(subfeature_param, 0, ONFI_SUBFEATURE_PARAM_LEN); > > chip->cmdfunc(mtd, NAND_CMD_GET_FEATURES, addr, -1); > - chip->read_buf(mtd, subfeature_param, ONFI_SUBFEATURE_PARAM_LEN); > + for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i) > + *subfeature_param++ = chip->read_byte(mtd); > return 0; > } > > @@ -2804,6 +2854,8 @@ static void nand_set_defaults(struct nand_chip *chip, int busw) > chip->block_markbad = nand_default_block_markbad; > if (!chip->write_buf) > chip->write_buf = busw ? nand_write_buf16 : nand_write_buf; > + if (!chip->write_byte) > + chip->write_byte = busw ? nand_write_byte16 : nand_write_byte; > if (!chip->read_buf) > chip->read_buf = busw ? nand_read_buf16 : nand_read_buf; > if (!chip->scan_bbt) > diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h > index 7ccb3c5..8ee4ed1 100644 > --- a/include/linux/mtd/nand.h > +++ b/include/linux/mtd/nand.h > @@ -419,6 +419,8 @@ struct nand_buffers { > * flash device. > * @read_byte: [REPLACEABLE] read one byte from the chip > * @read_word: [REPLACEABLE] read one word from the chip > + * @write_byte [REPLACEABLE] write a single byte to the chip on the > + * low 8 I/O lines > * @write_buf: [REPLACEABLE] write data from the buffer to the chip > * @read_buf: [REPLACEABLE] read data from the chip into the buffer > * @select_chip: [REPLACEABLE] select chip nr > @@ -503,6 +505,7 @@ struct nand_chip { > > uint8_t (*read_byte)(struct mtd_info *mtd); > u16 (*read_word)(struct mtd_info *mtd); > + void (*write_byte)(struct mtd_info *mtd, uint8_t byte); > void (*write_buf)(struct mtd_info *mtd, const uint8_t *buf, int len); > void (*read_buf)(struct mtd_info *mtd, uint8_t *buf, int len); > void (*select_chip)(struct mtd_info *mtd, int chip); > -- > 1.8.2.rc2 > >
于 2013年03月05日 00:50, Uwe Kleine-König 写道: > @Huang Shijie: I didn't carry over your Ack to this new patch. Are you > still happy with this one? it's ok. :) thanks Huang Shijie
On Mon, 2013-03-04 at 17:47 +0100, Uwe Kleine-König wrote: > diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h > index 7ccb3c5..8ee4ed1 100644 > --- a/include/linux/mtd/nand.h > +++ b/include/linux/mtd/nand.h > @@ -419,6 +419,8 @@ struct nand_buffers { > * flash device. > * @read_byte: [REPLACEABLE] read one byte from the chip > * @read_word: [REPLACEABLE] read one word from the chip > + * @write_byte [REPLACEABLE] write a single byte to the chip on the > + * low 8 I/O lines > * @write_buf: [REPLACEABLE] write data from the buffer to the chip > * @read_buf: [REPLACEABLE] read data from the chip into the buffer > * @select_chip: [REPLACEABLE] select chip nr > @@ -503,6 +505,7 @@ struct nand_chip { > > uint8_t (*read_byte)(struct mtd_info *mtd); > u16 (*read_word)(struct mtd_info *mtd); > + void (*write_byte)(struct mtd_info *mtd, uint8_t byte); > void (*write_buf)(struct mtd_info *mtd, const uint8_t *buf, int len); > void (*read_buf)(struct mtd_info *mtd, uint8_t *buf, int len); > void (*select_chip)(struct mtd_info *mtd, int chip); I would like to make the interface symmetric for read and write. I do not have any 16 bit flashes, so need to somehow encouredge someone who has one to do this. Namely, I'd like to kill 'read_word()', if possible. What's your take on this?
On Mon, 2013-03-04 at 17:47 +0100, Uwe Kleine-König wrote: > According to the Open NAND Flash Interface Specification (ONFI) Revision > 3.1 "Parameters are always transferred on the lower 8-bits of the data > bus." for the Get Features and Set Features commands. > > So using read_buf and write_buf is wrong for 16-bit wide nand chips as > they use I/O[15:0]. The Get Features command is easily fixed using 4 > times the read_byte callback. For Set Features implement a new > overwritable callback "write_byte". Still I expect the default to work > just fine for all controllers. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Pushed to l2-mtd.git, thanks!
On Mon, 2013-03-04 at 17:47 +0100, Uwe Kleine-König wrote: > + */ > +static void nand_write_byte16(struct mtd_info *mtd, uint8_t byte) > +{ > + struct nand_chip *chip = mtd->priv; > + > + /* > + * It's not entirely clear what should happen to I/O[15:8] when writing > + * a byte. The ONFi spec (Revision 3.1; 2012-09-19, Section 2.16) reads: > + * > + * When the host supports a 16-bit bus width, only data is > + * transferred at the 16-bit width. All address and command line > + * transfers shall use only the lower 8-bits of the data bus. During > + * command transfers, the host may place any value on the upper > + * 8-bits of the data bus. During address transfers, the host shall > + * set the upper 8-bits of the data bus to 00h. > + * > + * One user of the write_byte callback is nand_onfi_set_features. The > + * four parameters are specified to be written to I/O[7:0], but this is > + * neither an address nor a command transfer. Let's assume a 0 on the > + * upper I/O lines is OK. > + */ > + chip->write_buf(mtd, (uint8_t[]){ byte, 0 }, 2); Ick. Can you declare that array separately, rather than in the function call please? And also this seems broken on big-endian. nand_write_buf16() will cast the 'buf' pointer to a uint16_t *, load a single uint16_t from it (for example 0x5a00 if byte==0x5a), and proceed to write the 'byte' value on the *high* side of the data bus, not the low side. Won't it?
On Wed, Mar 13, 2013 at 11:33:04AM +0200, Artem Bityutskiy wrote: > On Mon, 2013-03-04 at 17:47 +0100, Uwe Kleine-König wrote: > > diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h > > index 7ccb3c5..8ee4ed1 100644 > > --- a/include/linux/mtd/nand.h > > +++ b/include/linux/mtd/nand.h > > @@ -419,6 +419,8 @@ struct nand_buffers { > > * flash device. > > * @read_byte: [REPLACEABLE] read one byte from the chip > > * @read_word: [REPLACEABLE] read one word from the chip > > + * @write_byte [REPLACEABLE] write a single byte to the chip on the > > + * low 8 I/O lines > > * @write_buf: [REPLACEABLE] write data from the buffer to the chip > > * @read_buf: [REPLACEABLE] read data from the chip into the buffer > > * @select_chip: [REPLACEABLE] select chip nr > > @@ -503,6 +505,7 @@ struct nand_chip { > > > > uint8_t (*read_byte)(struct mtd_info *mtd); > > u16 (*read_word)(struct mtd_info *mtd); > > + void (*write_byte)(struct mtd_info *mtd, uint8_t byte); > > void (*write_buf)(struct mtd_info *mtd, const uint8_t *buf, int len); > > void (*read_buf)(struct mtd_info *mtd, uint8_t *buf, int len); > > void (*select_chip)(struct mtd_info *mtd, int chip); > > I would like to make the interface symmetric for read and write. I do > not have any 16 bit flashes, so need to somehow encouredge someone who > has one to do this. Namely, I'd like to kill 'read_word()', if possible. > What's your take on this? I don't have a 16 bit flash, so I have the same excuse as you do :-) Uwe
+ Pekon, Ezequiel On Tue, Nov 26, 2013 at 10:03:41PM +0100, Uwe Kleine-König wrote: > On Wed, Mar 13, 2013 at 11:33:04AM +0200, Artem Bityutskiy wrote: Resurrecting a really old thread, eh? :) I like it! > > On Mon, 2013-03-04 at 17:47 +0100, Uwe Kleine-König wrote: > > > diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h > > > index 7ccb3c5..8ee4ed1 100644 > > > --- a/include/linux/mtd/nand.h > > > +++ b/include/linux/mtd/nand.h > > > @@ -419,6 +419,8 @@ struct nand_buffers { > > > * flash device. > > > * @read_byte: [REPLACEABLE] read one byte from the chip > > > * @read_word: [REPLACEABLE] read one word from the chip > > > + * @write_byte [REPLACEABLE] write a single byte to the chip on the > > > + * low 8 I/O lines > > > * @write_buf: [REPLACEABLE] write data from the buffer to the chip > > > * @read_buf: [REPLACEABLE] read data from the chip into the buffer > > > * @select_chip: [REPLACEABLE] select chip nr > > > @@ -503,6 +505,7 @@ struct nand_chip { > > > > > > uint8_t (*read_byte)(struct mtd_info *mtd); > > > u16 (*read_word)(struct mtd_info *mtd); > > > + void (*write_byte)(struct mtd_info *mtd, uint8_t byte); > > > void (*write_buf)(struct mtd_info *mtd, const uint8_t *buf, int len); > > > void (*read_buf)(struct mtd_info *mtd, uint8_t *buf, int len); > > > void (*select_chip)(struct mtd_info *mtd, int chip); > > > > I would like to make the interface symmetric for read and write. I do > > not have any 16 bit flashes, so need to somehow encouredge someone who > > has one to do this. Namely, I'd like to kill 'read_word()', if possible. > > What's your take on this? > I don't have a 16 bit flash, so I have the same excuse as you do :-) Ezequiel and Pekon have 16-bit devices and can do testing, I think. They also may be interested in your v3 patch. Brian
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 3766682..956b499 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -205,6 +205,50 @@ static void nand_select_chip(struct mtd_info *mtd, int chipnr) } /** + * nand_write_byte - [DEFAULT] write single byte to chip + * @mtd: MTD device structure + * @byte: value to write + * + * Default function to write a byte to I/O[7:0] + */ +static void nand_write_byte(struct mtd_info *mtd, uint8_t byte) +{ + struct nand_chip *chip = mtd->priv; + + chip->write_buf(mtd, &byte, 1); +} + +/** + * nand_write_byte16 - [DEFAULT] write single byte to a chip with width 16 + * @mtd: MTD device structure + * @byte: value to write + * + * Default function to write a byte to I/O[7:0] on a 16-bit wide chip. + */ +static void nand_write_byte16(struct mtd_info *mtd, uint8_t byte) +{ + struct nand_chip *chip = mtd->priv; + + /* + * It's not entirely clear what should happen to I/O[15:8] when writing + * a byte. The ONFi spec (Revision 3.1; 2012-09-19, Section 2.16) reads: + * + * When the host supports a 16-bit bus width, only data is + * transferred at the 16-bit width. All address and command line + * transfers shall use only the lower 8-bits of the data bus. During + * command transfers, the host may place any value on the upper + * 8-bits of the data bus. During address transfers, the host shall + * set the upper 8-bits of the data bus to 00h. + * + * One user of the write_byte callback is nand_onfi_set_features. The + * four parameters are specified to be written to I/O[7:0], but this is + * neither an address nor a command transfer. Let's assume a 0 on the + * upper I/O lines is OK. + */ + chip->write_buf(mtd, (uint8_t[]){ byte, 0 }, 2); +} + +/** * nand_write_buf - [DEFAULT] write buffer to chip * @mtd: MTD device structure * @buf: data buffer @@ -2710,7 +2754,7 @@ static int nand_block_markbad(struct mtd_info *mtd, loff_t ofs) } /** - * nand_onfi_set_features- [REPLACEABLE] set features for ONFI nand + * nand_onfi_set_features - [REPLACEABLE] set features for ONFI nand * @mtd: MTD device structure * @chip: nand chip info structure * @addr: feature address. @@ -2720,12 +2764,15 @@ static int nand_onfi_set_features(struct mtd_info *mtd, struct nand_chip *chip, int addr, uint8_t *subfeature_param) { int status; + int i; if (!chip->onfi_version) return -EINVAL; chip->cmdfunc(mtd, NAND_CMD_SET_FEATURES, addr, -1); - chip->write_buf(mtd, subfeature_param, ONFI_SUBFEATURE_PARAM_LEN); + for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i) + chip->write_byte(mtd, subfeature_param[i]); + status = chip->waitfunc(mtd, chip); if (status & NAND_STATUS_FAIL) return -EIO; @@ -2733,7 +2780,7 @@ static int nand_onfi_set_features(struct mtd_info *mtd, struct nand_chip *chip, } /** - * nand_onfi_get_features- [REPLACEABLE] get features for ONFI nand + * nand_onfi_get_features - [REPLACEABLE] get features for ONFI nand * @mtd: MTD device structure * @chip: nand chip info structure * @addr: feature address. @@ -2742,6 +2789,8 @@ static int nand_onfi_set_features(struct mtd_info *mtd, struct nand_chip *chip, static int nand_onfi_get_features(struct mtd_info *mtd, struct nand_chip *chip, int addr, uint8_t *subfeature_param) { + int i; + if (!chip->onfi_version) return -EINVAL; @@ -2749,7 +2798,8 @@ static int nand_onfi_get_features(struct mtd_info *mtd, struct nand_chip *chip, memset(subfeature_param, 0, ONFI_SUBFEATURE_PARAM_LEN); chip->cmdfunc(mtd, NAND_CMD_GET_FEATURES, addr, -1); - chip->read_buf(mtd, subfeature_param, ONFI_SUBFEATURE_PARAM_LEN); + for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i) + *subfeature_param++ = chip->read_byte(mtd); return 0; } @@ -2804,6 +2854,8 @@ static void nand_set_defaults(struct nand_chip *chip, int busw) chip->block_markbad = nand_default_block_markbad; if (!chip->write_buf) chip->write_buf = busw ? nand_write_buf16 : nand_write_buf; + if (!chip->write_byte) + chip->write_byte = busw ? nand_write_byte16 : nand_write_byte; if (!chip->read_buf) chip->read_buf = busw ? nand_read_buf16 : nand_read_buf; if (!chip->scan_bbt) diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 7ccb3c5..8ee4ed1 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -419,6 +419,8 @@ struct nand_buffers { * flash device. * @read_byte: [REPLACEABLE] read one byte from the chip * @read_word: [REPLACEABLE] read one word from the chip + * @write_byte [REPLACEABLE] write a single byte to the chip on the + * low 8 I/O lines * @write_buf: [REPLACEABLE] write data from the buffer to the chip * @read_buf: [REPLACEABLE] read data from the chip into the buffer * @select_chip: [REPLACEABLE] select chip nr @@ -503,6 +505,7 @@ struct nand_chip { uint8_t (*read_byte)(struct mtd_info *mtd); u16 (*read_word)(struct mtd_info *mtd); + void (*write_byte)(struct mtd_info *mtd, uint8_t byte); void (*write_buf)(struct mtd_info *mtd, const uint8_t *buf, int len); void (*read_buf)(struct mtd_info *mtd, uint8_t *buf, int len); void (*select_chip)(struct mtd_info *mtd, int chip);