[U-Boot] [PATCH v4 16/16] spi: Add SPI NOR protection mechanism

[Jagan Teki <jteki@openedev.com>]

Hi Fabio,

On 26 October 2015 at 21:41, Fabio Estevam <fabio.estevam@freescale.com> wrote:
> Many SPI flashes have protection bits (BP2, BP1 and BP0) in the
> status register that can protect selected regions of the SPI NOR.
>
> Take these bits into account when performing erase operations,
> making sure that the protected areas are skipped.
>
> Tested on a mx6qsabresd:
>
> => sf probe
> SF: Detected M25P32 with page size 256 Bytes, erase size 64 KiB, total 4 MiB
> => sf protect lock  0x3f0000 0x10000
> => sf erase 0x3f0000 0x10000
> offset 0x3f0000 is protected and cannot be erased
> SF: 65536 bytes @ 0x3f0000 Erased: ERROR
> => sf protect unlock  0x3f0000 0x10000
> => sf erase 0x3f0000 0x10000
> SF: 65536 bytes @ 0x3f0000 Erased: OK
>
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
> Reviewed-by: Tom Rini <trini@konsulko.com>
> Reviewed-by: Heiko Schocher <hs@denx.de>
> ---
> Changes since v3:
> - None
>
>  common/cmd_sf.c               | 35 +++++++++++++++++++++++++++++++++++
>  drivers/mtd/spi/sf-uclass.c   |  8 ++++++++
>  drivers/mtd/spi/sf_internal.h |  8 ++++++++
>  drivers/mtd/spi/sf_ops.c      | 25 +++++++++++++++++++++++++
>  drivers/mtd/spi/sf_probe.c    | 31 +++++++++++++++++++++++++++++++
>  include/spi_flash.h           | 41 +++++++++++++++++++++++++++++++++++++++++
>  6 files changed, 148 insertions(+)
>
> diff --git a/common/cmd_sf.c b/common/cmd_sf.c
> index ac7f5df..42862d9 100644
> --- a/common/cmd_sf.c
> +++ b/common/cmd_sf.c
> @@ -348,6 +348,37 @@ static int do_spi_flash_erase(int argc, char * const argv[])
>         return ret == 0 ? 0 : 1;
>  }
>
> +static int do_spi_protect(int argc, char * const argv[])
> +{
> +       int ret = 0;
> +       loff_t start, len;
> +       bool prot = false;
> +
> +       if (argc != 4)
> +               return -1;
> +
> +       if (!str2off(argv[2], &start)) {
> +               puts("start sector is not a valid number\n");
> +               return 1;
> +       }
> +
> +       if (!str2off(argv[3], &len)) {
> +               puts("len is not a valid number\n");
> +               return 1;
> +       }
> +
> +       if (strcmp(argv[1], "lock") == 0)
> +               prot = true;
> +       else if (strcmp(argv[1], "unlock") == 0)
> +               prot = false;
> +       else

Don't we have is_locked command from user? may be we can all this one as well.

> +               return -1;  /* Unknown parameter */
> +
> +       ret = spi_flash_protect(flash, start, len, prot);
> +
> +       return ret == 0 ? 0 : 1;
> +}
> +
>  #ifdef CONFIG_CMD_SF_TEST
>  enum {
>         STAGE_ERASE,
> @@ -540,6 +571,8 @@ static int do_spi_flash(cmd_tbl_t *cmdtp, int flag, int argc,
>                 ret = do_spi_flash_read_write(argc, argv);
>         else if (strcmp(cmd, "erase") == 0)
>                 ret = do_spi_flash_erase(argc, argv);
> +       else if (strcmp(cmd, "protect") == 0)
> +               ret = do_spi_protect(argc, argv);
>  #ifdef CONFIG_CMD_SF_TEST
>         else if (!strcmp(cmd, "test"))
>                 ret = do_spi_flash_test(argc, argv);
> @@ -579,5 +612,7 @@ U_BOOT_CMD(
>         "sf update addr offset|partition len    - erase and write `len' bytes from memory\n"
>         "                                         at `addr' to flash at `offset'\n"
>         "                                         or to start of mtd `partition'\n"
> +       "sf protect lock/unlock sector len      - protect/unprotect 'len' bytes starting\n"
> +       "                                         at address 'sector'\n"
>         SF_TEST_HELP
>  );
> diff --git a/drivers/mtd/spi/sf-uclass.c b/drivers/mtd/spi/sf-uclass.c
> index 350e21a..7663885 100644
> --- a/drivers/mtd/spi/sf-uclass.c
> +++ b/drivers/mtd/spi/sf-uclass.c
> @@ -27,6 +27,14 @@ int spi_flash_erase_dm(struct udevice *dev, u32 offset, size_t len)
>         return sf_get_ops(dev)->erase(dev, offset, len);
>  }
>
> +int spi_flash_protect_dm(struct udevice *dev, u32 offset, size_t len, bool prot)
> +{
> +       if (prot)
> +               return sf_get_ops(dev)->lock(dev, offset, len);
> +       else
> +               return sf_get_ops(dev)->unlock(dev, offset, len);
> +}
> +
>  /*
>   * TODO(sjg at chromium.org): This is an old-style function. We should remove
>   * it when all SPI flash drivers use dm
> diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
> index 9c95d56..33be598 100644
> --- a/drivers/mtd/spi/sf_internal.h
> +++ b/drivers/mtd/spi/sf_internal.h
> @@ -168,6 +168,10 @@ int spi_flash_cmd_read_status(struct spi_flash *flash, u8 *rs);
>  /* Program the status register */
>  int spi_flash_cmd_write_status(struct spi_flash *flash, u8 ws);
>
> +int stm_is_locked(struct spi_flash *nor, loff_t ofs, u32 len);
> +int stm_lock(struct spi_flash *nor, u32 ofs, u32 len);
> +int stm_unlock(struct spi_flash *nor, u32 ofs, u32 len);
> +
>  /* Read the config register */
>  int spi_flash_cmd_read_config(struct spi_flash *flash, u8 *rc);
>
> @@ -222,6 +226,10 @@ int spi_flash_read_common(struct spi_flash *flash, const u8 *cmd,
>  int spi_flash_cmd_read_ops(struct spi_flash *flash, u32 offset,
>                 size_t len, void *data);
>
> +int spi_flash_cmd_lock_ops(struct spi_flash *flash, u32 offset, size_t len);
> +int spi_flash_cmd_unlock_ops(struct spi_flash *flash, u32 offset, size_t len);
> +int spi_flash_cmd_is_locked_ops(struct spi_flash *flash, u32 offset, size_t len);
> +
>  #ifdef CONFIG_SPI_FLASH_MTD
>  int spi_flash_mtd_register(struct spi_flash *flash);
>  void spi_flash_mtd_unregister(void);
> diff --git a/drivers/mtd/spi/sf_ops.c b/drivers/mtd/spi/sf_ops.c
> index 928f9c1..ee23bb2 100644
> --- a/drivers/mtd/spi/sf_ops.c
> +++ b/drivers/mtd/spi/sf_ops.c
> @@ -277,6 +277,11 @@ int spi_flash_cmd_erase_ops(struct spi_flash *flash, u32 offset, size_t len)
>                 return -1;
>         }
>
> +       if (flash->is_locked(flash, offset, len) > 0) {
> +               printf("offset 0x%x is protected and cannot be erased\n", offset);
> +               return -EINVAL;
> +       }
> +
>         cmd[0] = flash->erase_cmd;
>         while (len) {
>                 erase_addr = offset;
> @@ -319,6 +324,11 @@ int spi_flash_cmd_write_ops(struct spi_flash *flash, u32 offset,
>
>         page_size = flash->page_size;
>
> +       if (flash->is_locked(flash, offset, len) > 0) {
> +               printf("offset 0x%x is protected and cannot be written\n", offset);
> +               return -EINVAL;
> +       }
> +
>         cmd[0] = flash->write_cmd;
>         for (actual = 0; actual < len; actual += chunk_len) {
>                 write_addr = offset;
> @@ -357,6 +367,21 @@ int spi_flash_cmd_write_ops(struct spi_flash *flash, u32 offset,
>         return ret;
>  }
>
> +int spi_flash_cmd_lock_ops(struct spi_flash *flash, u32 offset, size_t len)
> +{
> +       return stm_lock(flash, offset, len);
> +}
> +
> +int spi_flash_cmd_unlock_ops(struct spi_flash *flash, u32 offset, size_t len)
> +{
> +       return stm_unlock(flash, offset, len);
> +}
> +
> +int spi_flash_cmd_is_locked_ops(struct spi_flash *flash, u32 offset, size_t len)
> +{
> +       return stm_is_locked(flash, offset, len);
> +}
> +
>  int spi_flash_read_common(struct spi_flash *flash, const u8 *cmd,
>                 size_t cmd_len, void *data, size_t data_len)
>  {
> diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
> index 954376d..0975a2f 100644
> --- a/drivers/mtd/spi/sf_probe.c
> +++ b/drivers/mtd/spi/sf_probe.c
> @@ -149,6 +149,11 @@ static int spi_flash_validate_params(struct spi_slave *spi, u8 *idcode,
>  #endif
>         flash->erase = spi_flash_cmd_erase_ops;
>         flash->read = spi_flash_cmd_read_ops;
> +#if defined(CONFIG_SPI_FLASH_STMICRO)
> +       flash->lock = spi_flash_cmd_lock_ops;
> +       flash->unlock = spi_flash_cmd_unlock_ops;
> +       flash->is_locked = spi_flash_cmd_is_locked_ops;
> +#endif

We need to check the idcode as well because if we compile other flash
vendor with micron, non-micron flash got initialized with these lock
ops' and also assign stm_* calls if the idcode is micro.

>  #endif
>
>         /* Compute the flash size */
> @@ -469,6 +474,27 @@ int spi_flash_std_erase(struct udevice *dev, u32 offset, size_t len)
>         return spi_flash_cmd_erase_ops(flash, offset, len);
>  }
>
> +int spi_flash_std_lock(struct udevice *dev, u32 offset, size_t len)
> +{
> +       struct spi_flash *flash = dev_get_uclass_priv(dev);
> +
> +       return spi_flash_cmd_lock_ops(flash, offset, len);
> +}
> +
> +int spi_flash_std_unlock(struct udevice *dev, u32 offset, size_t len)
> +{
> +       struct spi_flash *flash = dev_get_uclass_priv(dev);
> +
> +       return spi_flash_cmd_unlock_ops(flash, offset, len);
> +}
> +
> +int spi_flash_std_is_locked(struct udevice *dev, u32 offset, size_t len)
> +{
> +       struct spi_flash *flash = dev_get_uclass_priv(dev);
> +
> +       return spi_flash_cmd_is_locked_ops(flash, offset, len);
> +}
> +
>  int spi_flash_std_probe(struct udevice *dev)
>  {
>         struct spi_slave *slave = dev_get_parentdata(dev);
> @@ -485,6 +511,11 @@ static const struct dm_spi_flash_ops spi_flash_std_ops = {
>         .read = spi_flash_std_read,
>         .write = spi_flash_std_write,
>         .erase = spi_flash_std_erase,
> +#if defined(CONFIG_SPI_FLASH_STMICRO)
> +       .lock = spi_flash_std_lock,
> +       .unlock = spi_flash_std_unlock,
> +       .is_locked = spi_flash_std_is_locked,
> +#endif

This should be changes as I pointed above with non-dm, probably we can
assign lock func_ptr's in probe by checking idcode.

>  };
>
>  static const struct udevice_id spi_flash_std_ids[] = {
> diff --git a/include/spi_flash.h b/include/spi_flash.h
> index 73b2b0a..4d55ba7 100644
> --- a/include/spi_flash.h
> +++ b/include/spi_flash.h
> @@ -110,6 +110,9 @@ struct spi_flash {
>                         const void *buf);
>         int (*erase)(struct spi_flash *flash, u32 offset, size_t len);
>  #endif
> +       int (*lock)(struct spi_flash *flash, u32 offset, size_t len);
> +       int (*unlock)(struct spi_flash *flash, u32 offset, size_t len);
> +       int (*is_locked)(struct spi_flash *flash, u32 offset, size_t len);
>  };
>
>  struct dm_spi_flash_ops {
> @@ -117,6 +120,9 @@ struct dm_spi_flash_ops {
>         int (*write)(struct udevice *dev, u32 offset, size_t len,
>                      const void *buf);
>         int (*erase)(struct udevice *dev, u32 offset, size_t len);
> +       int (*lock)(struct udevice *dev, u32 offset, size_t len);
> +       int (*unlock)(struct udevice *dev, u32 offset, size_t len);
> +       int (*is_locked)(struct udevice *dev, u32 offset, size_t len);
>  };
>
>  /* Access the serial operations for a device */
> @@ -158,6 +164,20 @@ int spi_flash_write_dm(struct udevice *dev, u32 offset, size_t len,
>   */
>  int spi_flash_erase_dm(struct udevice *dev, u32 offset, size_t len);
>
> +/**
> + * spi_flash_protect_dm() - Protect/unprotect blocks of the SPI flash
> + *
> + * Note that @len must be a muiltiple of the flash sector size.
> + *
> + * @dev:       SPI flash device
> + * @offset:    Offset into device in bytes to start erasing
> + * @len:       Number of bytes to erase
> + * @prot:      True: lock the block or False: unlock the block
> + * @return 0 if OK, -ve on error
> + */
> +int spi_flash_protect_dm(struct udevice *dev, u32 offset, size_t len,
> +                        bool prot);
> +
>  int spi_flash_probe_bus_cs(unsigned int busnum, unsigned int cs,
>                            unsigned int max_hz, unsigned int spi_mode,
>                            struct udevice **devp);
> @@ -189,6 +209,15 @@ static inline int spi_flash_erase(struct spi_flash *flash, u32 offset,
>         return spi_flash_erase_dm(flash->dev, offset, len);
>  }
>
> +static inline int spi_flash_protect(struct spi_flash *flash, loff_t ofs,
> +                                   u32 len, bool prot)
> +{
> +       if (!flash->lock)
> +               return -EOPNOTSUPP;
> +
> +       return spi_flash_protect_dm(flash->dev, ofs, len, prot);
> +}
> +
>  struct sandbox_state;
>
>  int sandbox_sf_bind_emul(struct sandbox_state *state, int busnum, int cs,
> @@ -231,6 +260,18 @@ static inline int spi_flash_erase(struct spi_flash *flash, u32 offset,
>  {
>         return flash->erase(flash, offset, len);
>  }
> +
> +static inline int spi_flash_protect(struct spi_flash *flash, u32 ofs, u32 len,
> +                                   bool prot)
> +{
> +       if (!flash->lock)
> +               return -EOPNOTSUPP;
> +
> +       if (prot)
> +               return flash->lock(flash, ofs, len);
> +       else
> +               return flash->unlock(flash, ofs, len);
> +}
>  #endif
>
>  void spi_boot(void) __noreturn;
> --
> 1.9.1
>

thanks!
-- 
Jagan | openedev.