Re: [PATCH RESEND] mtd: spi-nor: Add support for S3AN spi-nor devices

From: Brian Norris
Date: Thu May 05 2016 - 20:56:27 EST

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On Wed, Apr 27, 2016 at 03:14:22PM +0200, Ricardo Ribalda Delgado wrote:
> Xilinx Spartan-3AN contain an embedded spi device where they keep their
> configuration data and optionally some user data.
>
> The protocol of this flash follows most of the spi-nor standard. With
> the following differences:
>
> - Page size might not be a power of two.
> - The address calculation.
> - The spi nor commands used.
>
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
> ---
>
> I did send this patch 3 months ago with no feedback.
> I have rebased the code to the latest version of mtd/master
>
>
> drivers/mtd/devices/m25p80.c | 3 ++
> drivers/mtd/spi-nor/spi-nor.c | 96 +++++++++++++++++++++++++++++++++++++++++--
> include/linux/mtd/spi-nor.h | 13 ++++++
> 3 files changed, 109 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
> index c9c3b7fa3051..869576735978 100644
> --- a/drivers/mtd/devices/m25p80.c
> +++ b/drivers/mtd/devices/m25p80.c
> @@ -49,6 +49,9 @@ static int m25p80_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len)
>
> static void m25p_addr2cmd(struct spi_nor *nor, unsigned int addr, u8 *cmd)
> {
> + if (nor->addr_convert)
> + addr = nor->addr_convert(nor, addr);
> +
> /* opcode is in cmd[0] */
> cmd[1] = addr >> (nor->addr_width * 8 - 8);
> cmd[2] = addr >> (nor->addr_width * 8 - 16);
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 157841dc3e99..d07d763fcfc4 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -75,6 +75,7 @@ struct flash_info {
> * bit. Must be used with
> * SPI_NOR_HAS_LOCK.
> */
> +#define SPI_S3AN BIT(10) /* Xililnx S3AN Embedded SPI nor*/

Spacing is wrong. Please add a space between "nor" and "*/".

> };
>
> #define JEDEC_MFR(info) ((info)->id[0])
> @@ -217,6 +218,21 @@ static inline int set_4byte(struct spi_nor *nor, const struct flash_info *info,
> return nor->write_reg(nor, SPINOR_OP_BRWR, nor->cmd_buf, 1);
> }
> }
> +
> +static inline int s3an_sr_ready(struct spi_nor *nor)

We should probably remove some of the inline eslewhere. Drop it, and let
the compiler decide.

> +{
> + int ret;
> + u8 val;
> +
> + ret = nor->read_reg(nor, SPINOR_OP_XRDSR, &val, 1);
> + if (ret < 0) {
> + pr_err("error %d reading SR\n", (int) ret);
> + return ret;
> + }
> +
> + return !!(val & XSR_RDY);
> +}
> +
> static inline int spi_nor_sr_ready(struct spi_nor *nor)
> {
> int sr = read_sr(nor);
> @@ -238,7 +254,7 @@ static inline int spi_nor_fsr_ready(struct spi_nor *nor)
> static int spi_nor_ready(struct spi_nor *nor)
> {
> int sr, fsr;
> - sr = spi_nor_sr_ready(nor);
> + sr = nor->sr_ready(nor);
> if (sr < 0)
> return sr;
> fsr = nor->flags & SNOR_F_USE_FSR ? spi_nor_fsr_ready(nor) : 1;
> @@ -334,6 +350,9 @@ static int spi_nor_erase_sector(struct spi_nor *nor, u32 addr)
> * Default implementation, if driver doesn't have a specialized HW
> * control
> */
> + if (nor->addr_convert)
> + addr = nor->addr_convert(nor, addr);
> +
> for (i = nor->addr_width - 1; i >= 0; i--) {
> buf[i] = addr & 0xff;
> addr >>= 8;
> @@ -368,7 +387,7 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
> return ret;
>
> /* whole-chip erase? */
> - if (len == mtd->size) {
> + if (len == mtd->size && !(nor->flags & SNOR_F_NO_OP_CHIP_ERASE)) {
> unsigned long timeout;
>
> write_enable(nor);
> @@ -782,6 +801,19 @@ static int spi_nor_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> .addr_width = (_addr_width), \
> .flags = (_flags),
>
> +#define S3AN_INFO(_jedec_id, _n_sectors, _page_size) \
> + .id = { \
> + ((_jedec_id) >> 16) & 0xff, \
> + ((_jedec_id) >> 8) & 0xff, \
> + (_jedec_id) & 0xff \
> + }, \
> + .id_len = 3, \
> + .sector_size = (8*_page_size), \
> + .n_sectors = (_n_sectors), \
> + .page_size = _page_size, \
> + .addr_width = 3, \
> + .flags = SPI_NOR_NO_FR | SPI_S3AN,
> +
> /* NOTE: double check command sets and memory organization when you add
> * more nor chips. This current list focusses on newer chips, which
> * have been converging on command sets which including JEDEC ID.
> @@ -991,6 +1023,13 @@ static const struct flash_info spi_nor_ids[] = {
> { "cat25c09", CAT25_INFO( 128, 8, 32, 2, SPI_NOR_NO_ERASE | SPI_NOR_NO_FR) },
> { "cat25c17", CAT25_INFO( 256, 8, 32, 2, SPI_NOR_NO_ERASE | SPI_NOR_NO_FR) },
> { "cat25128", CAT25_INFO(2048, 8, 64, 2, SPI_NOR_NO_ERASE | SPI_NOR_NO_FR) },
> +
> + /* Xilinx S3AN Internal Flash */
> + { "3S50AN", S3AN_INFO(0x1f2200, 64, 264) },
> + { "3S200AN", S3AN_INFO(0x1f2400, 256, 264) },
> + { "3S400AN", S3AN_INFO(0x1f2400, 256, 264) },
> + { "3S700AN", S3AN_INFO(0x1f2500, 512, 264) },
> + { "3S1400AN", S3AN_INFO(0x1f2600, 512, 528) },
> { },
> };
>
> @@ -1122,7 +1161,13 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
>
> write_enable(nor);
>
> - page_offset = to & (nor->page_size - 1);
> + if (hweight32(nor->page_size) == 1)
> + page_offset = to & (nor->page_size - 1);
> + else {
> + uint64_t aux = to;
> +
> + page_offset = do_div(aux, nor->page_size);
> + }
>
> /* do all the bytes fit onto one page? */
> if (page_offset + len <= nor->page_size) {
> @@ -1250,6 +1295,43 @@ static int spi_nor_check(struct spi_nor *nor)
> return 0;
> }
>
> +static unsigned int s3an_addr_convert(struct spi_nor *nor, unsigned int addr)
> +{
> + if (nor->page_size == 264)
> + return (addr / 264) * 512 + (addr % 264);
> +
> + return (addr / 528) * 1024 + (addr % 528);
> +}

Whoa this is fugly. Why does this mode exist? Can we ignore it and just
use the poewr-of-two mode? If not, I think we need a bit more verbose of
comments in the code to explain what/why we are doing.

> +
> +static int s3an_nor_scan(const struct flash_info *info, struct spi_nor *nor)
> +{
> + int ret;
> + u8 val;
> +
> + ret = nor->read_reg(nor, SPINOR_OP_XRDSR, &val, 1);
> + if (ret < 0) {
> + pr_err("error %d reading SR\n", (int) ret);
> + return ret;
> + }
> +
> + nor->erase_opcode = SPINOR_OP_XSE;
> + nor->program_opcode = SPINOR_OP_XPP;
> + nor->read_opcode = SPINOR_OP_READ;
> + nor->sr_ready = s3an_sr_ready;

No, we don't need another function callback. Can't we use a SNOR_F_...
flag?

> + nor->flags |= SNOR_F_NO_OP_CHIP_ERASE;
> +
> + /*Flash in Power of 2 mode*/
> + if (val & XSR_PAGESIZE) {
> + nor->page_size = (nor->page_size == 264) ? 256 : 512;
> + nor->mtd.writebufsize = nor->page_size;
> + nor->mtd.size = 8 * nor->page_size * info->n_sectors;
> + nor->mtd.erasesize = 8 * nor->page_size;
> + } else

Mismatching braces? You should use this style:

if (foo) {
more than;
one line;
} else {
just one line;
}

> + nor->addr_convert = s3an_addr_convert;
> +
> + return 0;
> +}
> +
> int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
> {
> const struct flash_info *info = NULL;
> @@ -1415,6 +1497,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
> }
>
> nor->program_opcode = SPINOR_OP_PP;
> + nor->sr_ready = spi_nor_sr_ready;
>
> if (info->addr_width)
> nor->addr_width = info->addr_width;
> @@ -1455,6 +1538,13 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
>
> nor->read_dummy = spi_nor_read_dummy_cycles(nor);
>
> + if (info->flags & SPI_S3AN) {

Maybe instead of this flag, you can just use the mfr ID? So:

if (JEDEC_MFR(info) == SNOR_MFR_...) { // what would you call the "manfacturer" here anyway?

> + ret = s3an_nor_scan(info, nor);
> +
> + if (ret)
> + return ret;
> + }
> +
> dev_info(dev, "%s (%lld Kbytes)\n", info->name,
> (long long)mtd->size >> 10);
>
> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> index 3c36113a88e1..0d4b57a0ccd6 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -67,6 +67,15 @@
> #define SPINOR_OP_WRDI 0x04 /* Write disable */
> #define SPINOR_OP_AAI_WP 0xad /* Auto address increment word program */
>
> +/* Used for S3AN flashes only */
> +#define SPINOR_OP_XSE 0x50 /* Sector erase */
> +#define SPINOR_OP_XPP 0x82 /* Page program */
> +#define SPINOR_OP_XRDSR 0xd7 /* Read status register */
> +
> +#define XSR_PAGESIZE BIT(0) /* Page size in Po2 or Linear */
> +#define XSR_RDY BIT(7) /* Ready */
> +
> +
> /* Used for Macronix and Winbond flashes. */
> #define SPINOR_OP_EN4B 0xb7 /* Enter 4-byte mode */
> #define SPINOR_OP_EX4B 0xe9 /* Exit 4-byte mode */
> @@ -118,6 +127,7 @@ enum spi_nor_ops {
> enum spi_nor_option_flags {
> SNOR_F_USE_FSR = BIT(0),
> SNOR_F_HAS_SR_TB = BIT(1),
> + SNOR_F_NO_OP_CHIP_ERASE = BIT(2),
> };
>
> /**
> @@ -172,6 +182,9 @@ struct spi_nor {
> int (*read_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len);
> int (*write_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len);
>
> + int (*sr_ready)(struct spi_nor *nor);
> + unsigned int (*addr_convert)(struct spi_nor *nor, unsigned int addr);
> +
> int (*read)(struct spi_nor *nor, loff_t from,
> size_t len, size_t *retlen, u_char *read_buf);
> void (*write)(struct spi_nor *nor, loff_t to,

Brian

Next message: Yinghai Lu: "Re: [PATCH v11 04/60] sparc/PCI: Use correct offset for bus address to resource"
Previous message: Andrew Lunn: "Re: [RFC PATCH net-next 13/20] net: dsa: mv88e6xxx: factorize GLOBAL_CONTROL setup"
Next in thread: Ricardo Ribalda Delgado: "Re: [PATCH RESEND] mtd: spi-nor: Add support for S3AN spi-nor devices"
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