Hi Ricardo,

Le 14/07/2016 à 22:18, Ricardo Ribalda Delgado a écrit :
> Xilinx Spartan-3AN FPGAs contain an In-System Flash 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 (default addressing mode).
> - The spi nor commands used.
> 
> Protocol is described on Xilinx User Guide UG333
> 
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.riba...@gmail.com>
> ---
> v4: 
> -Rebase on top of l2-mtd/master
> 
> v3: 
> -Rebase on top of mtd-next
> -Rename ADDR_NATIVE to ADDR_DEFAULT to follow UG333 naming
> -Fix bug on probe
> 
> v2: Suggested by Brian Norris <computersforpe...@gmail.com>
> 
> -Remove inline qualifier
> -Improve documentation of Default Addressing Mode
> -Convert function callbacks into SNOR_F_
> -Fix missmatch braces
> -Improve documentation of SPI_S3AN flag
> 
>  drivers/mtd/devices/m25p80.c  |   3 ++
>  drivers/mtd/spi-nor/spi-nor.c | 110 
> ++++++++++++++++++++++++++++++++++++++++--
>  include/linux/mtd/spi-nor.h   |  26 ++++++++++
>  3 files changed, 136 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
> index 9cf7fcd28034..a44465f2b73d 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->flags & SNOR_F_S3AN_ADDR_DEFAULT)
> +             addr = spi_nor_s3an_addr_convert(nor, addr);
> +

The address translation is done in spi-nor.c for Page Program and Sector Erase
operations. Why not be consistent and also do that translation in
spi_nor_read() in the very same file for (Fast) Read operations?

No need to modify m25p80.c or to export the spi_nor_s3an_addr_convert()
function.


>       /* 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 d0fc165d7d66..dce0a2f156e1 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -75,6 +75,12 @@ struct flash_info {
>                                        * bit. Must be used with
>                                        * SPI_NOR_HAS_LOCK.
>                                        */
> +#define      SPI_S3AN                BIT(10) /*
> +                                      * Xilinx Spartan 3AN In-System Flash
> +                                      * (MFR cannot be used for probing
> +                                      * because it has the same value as
> +                                      * ATMEL flashes)
> +                                     */
>  };
>  
>  #define JEDEC_MFR(info)      ((info)->id[0])
> @@ -217,6 +223,21 @@ 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 int s3an_sr_ready(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 XRDSR\n", (int) ret);
Maybe substitute "pr_err" with "dev_err(nor->dev, "
It would be more consistent with other error outputs in spi-nor.c.

> +             return ret;
> +     }
> +
> +     return !!(val & XSR_RDY);
> +}
> +
>  static inline int spi_nor_sr_ready(struct spi_nor *nor)
>  {
>       int sr = read_sr(nor);
> @@ -238,7 +259,9 @@ 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->flags & SNOR_F_READY_XSR_RDY ? s3an_sr_ready(nor) :
> +                                              spi_nor_sr_ready(nor);
>       if (sr < 0)
>               return sr;
>       fsr = nor->flags & SNOR_F_USE_FSR ? spi_nor_fsr_ready(nor) : 1;
> @@ -320,6 +343,23 @@ static void spi_nor_unlock_and_unprep(struct spi_nor 
> *nor, enum spi_nor_ops ops)
>  }
>  
>  /*
> + * This code converts an address to the Default Address Mode, that has non
> + * power of two page sizes. We must support this mode because it is the 
> default
> + * mode supported by Xilinx tools, it can access the whole flash area and
> + * changing over to the Power-of-two mode is irreversible and corrupts the
> + * original data.
> + */
> +unsigned int spi_nor_s3an_addr_convert(struct spi_nor *nor, unsigned int 
> addr)
> +{
> +     unsigned int offset;
> +
> +     offset = (nor->page_size == 264) ? (addr % 264) : (addr % 528);
> +
> +     return ((addr - offset) << 1) | offset;
> +}
> +EXPORT_SYMBOL_GPL(spi_nor_s3an_addr_convert);
> +
> +/*
>   * Initiate the erasure of a single sector
>   */
>  static int spi_nor_erase_sector(struct spi_nor *nor, u32 addr)
> @@ -330,6 +370,9 @@ static int spi_nor_erase_sector(struct spi_nor *nor, u32 
> addr)
>       if (nor->erase)
>               return nor->erase(nor, addr);
>  
> +     if (nor->flags & SNOR_F_S3AN_ADDR_DEFAULT)
> +             addr = spi_nor_s3an_addr_convert(nor, addr);
> +

Why not put the address translation before the if (nor->erase) test?

Actually it might be not blocking as I expect m25p80 to be the only driver
that can support S3AN memories and m25p80 no longer implement the .erase() hook
but relies on the .write_reg() hook instead.

Due to the address translation, I guess S3AN memories cannot be used with
system memory mapped SPI controllers.
>       /*
>        * Default implementation, if driver doesn't have a specialized HW
>        * control
> @@ -368,7 +411,7 @@ 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 +825,19 @@ 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.
> @@ -1009,6 +1065,13 @@ 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) },
>       { },
>  };
>  
> @@ -1171,7 +1234,13 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t 
> to, size_t len,
>       for (i = 0; i < len; ) {
>               ssize_t written;
>  
> -             page_offset = (to + i) & (nor->page_size - 1);
> +             if (hweight32(nor->page_size) == 1)
> +                     page_offset = to & (nor->page_size - 1);

The original formula was (to + i) & (nor->page_size - 1) whereas the new
formula is now to & (nor->page_size - 1).

It should be (to + i), shouldn't it? No change should be done for power of 2
page size.

> +             else {
> +                     uint64_t aux = to;
what about i ?
> +
> +                     page_offset = do_div(aux, nor->page_size);
> +             }
>               WARN_ONCE(page_offset,
>                         "Writing at offset %zu into a NOR page. Writing 
> partial pages may decrease reliability and increase wear of NOR flash.",
>                         page_offset);
> @@ -1300,6 +1369,35 @@ static int spi_nor_check(struct spi_nor *nor)
>       return 0;
>  }
>  
> +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 XRDSR\n", (int) ret);
> +             return ret;
> +     }
> +
> +     nor->erase_opcode = SPINOR_OP_XSE;
> +     nor->program_opcode = SPINOR_OP_XPP;
> +     nor->read_opcode = SPINOR_OP_READ;
> +     nor->flags |= SNOR_F_NO_OP_CHIP_ERASE | SNOR_F_READY_XSR_RDY;
> +
> +     /* 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 {
> +             nor->flags |= SNOR_F_S3AN_ADDR_DEFAULT;
> +     }
> +
> +     return 0;
> +}
> +
>  int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
>  {
>       const struct flash_info *info = NULL;
> @@ -1505,6 +1603,12 @@ 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) {
> +             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 c425c7b4c2a0..6378de414bca 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -68,6 +68,15 @@
>  #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 */
> @@ -119,6 +128,9 @@ 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),
> +     SNOR_F_S3AN_ADDR_DEFAULT = BIT(3),
> +     SNOR_F_READY_XSR_RDY    = BIT(4),
>  };
>  
>  /**
> @@ -197,6 +209,20 @@ static inline struct device_node 
> *spi_nor_get_flash_node(struct spi_nor *nor)
>       return mtd_get_of_node(&nor->mtd);
>  }
>  
> +
> +/**
> + * spi_nor_s3an_addr_convert() - convert an address to Default Address Mode
> + * @nor:     the spi_nor structure
> + * @addr:    the contiguous address value
> + *
> + * Spartan-3AN In-System Flash requires an special address mode to access its
> + * whole Flash area. This address mode, named Default Address Mode by Xilinx,
> + * has non power of two page sizes.
> + *
> + * Return: Address in Default Address Mode
> + */
> +unsigned int spi_nor_s3an_addr_convert(struct spi_nor *nor, unsigned int 
> addr);
> +
>  /**
>   * spi_nor_scan() - scan the SPI NOR
>   * @nor:     the spi_nor structure
> 

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