lkml.org 
[lkml]   [2020]   [Nov]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRe: [PATCH v6 4/5] mtd: spi-nor: atmel: Fix unlock_all() for AT25FS010/040
Date
On 11/26/20 10:26 PM, Michael Walle wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> These flashes have some weird BP bits mapping which aren't supported in
> the current locking code. Just add a simple unlock op to unprotect the
> entire flash array which is needed for legacy behavior.
>
> Signed-off-by: Michael Walle <michael@walle.cc>
> ---
> changes since v5
> - new patch
>
> drivers/mtd/spi-nor/atmel.c | 53 +++++++++++++++++++++++++++++++++++--
> drivers/mtd/spi-nor/core.c | 2 +-
> drivers/mtd/spi-nor/core.h | 1 +
> 3 files changed, 53 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/atmel.c b/drivers/mtd/spi-nor/atmel.c
> index 49d392c6c8bc..fe6a4653823d 100644
> --- a/drivers/mtd/spi-nor/atmel.c
> +++ b/drivers/mtd/spi-nor/atmel.c
> @@ -8,10 +8,59 @@
>
> #include "core.h"
>
> +/*
> + * The Atmel AT25FS010/AT25FS040 parts have some weird configuration for the
> + * block protection bits. We don't support them. But legacy behaviour in linux
> + * is to unlock the whole flash array on startup. Therefore, we have to support
> + * exactly this operation.
> + */
> +static int atmel_at25fs_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static int atmel_at25fs_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
> +{
> + /* We only support unlocking the whole flash array */
> + if (ofs || len != nor->params->size)
> + return -EINVAL;
> +
> + /*
> + * Write 0x00 to the status register to try to disable the write
> + * protection. This will fail if SRWD (the datasheet calls it WPEN) is
> + * set. But there is nothing we can do.
> + */

can't we do the same as you did in 5/5?
+ ret = spi_nor_read_sr(nor, nor->bouncebuf);
+ if (ret)
+ return ret;
+
+ sr = nor->bouncebuf[0];
+
+ if (sr & SR_SRWD) {
+ sr &= ~SR_SRWD;
+ ret = spi_nor_write_sr_and_check(nor, sr);
+ if (ret)
+ return ret;
+ }

If SRWD is set to 1, we first try to set it to 0. If WP# is asserted, we
will catch this in spi_nor_write_sr_and_check()

> + nor->bouncebuf[0] = 0;
> +
> + return spi_nor_write_sr(nor, nor->bouncebuf, 1);

and then you can use spi_nor_write_sr_and_check here

> +}
> +
> +static int atmel_at25fs_is_locked(struct spi_nor *nor, loff_t ofs, uint64_t len)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static const struct spi_nor_locking_ops atmel_at25fs_locking_ops = {
> + .lock = atmel_at25fs_lock,
> + .unlock = atmel_at25fs_unlock,
> + .is_locked = atmel_at25fs_is_locked,
> +};
> +
> +static void atmel_at25fs_default_init(struct spi_nor *nor)
> +{
> + nor->params->locking_ops = &atmel_at25fs_locking_ops;
> +}
> +
> +static const struct spi_nor_fixups atmel_at25fs_fixups = {
> + .default_init = atmel_at25fs_default_init,
> +};
> +
> static const struct flash_info atmel_parts[] = {
> /* Atmel -- some are (confusingly) marketed as "DataFlash" */
> - { "at25fs010", INFO(0x1f6601, 0, 32 * 1024, 4, SECT_4K | SPI_NOR_HAS_LOCK) },
> - { "at25fs040", INFO(0x1f6604, 0, 64 * 1024, 8, SECT_4K | SPI_NOR_HAS_LOCK) },
> + { "at25fs010", INFO(0x1f6601, 0, 32 * 1024, 4, SECT_4K | SPI_NOR_HAS_LOCK)
> + .fixups = &atmel_at25fs_fixups },
> + { "at25fs040", INFO(0x1f6604, 0, 64 * 1024, 8, SECT_4K | SPI_NOR_HAS_LOCK)
> + .fixups = &atmel_at25fs_fixups },
>
> { "at25df041a", INFO(0x1f4401, 0, 64 * 1024, 8, SECT_4K | SPI_NOR_HAS_LOCK) },
> { "at25df321", INFO(0x1f4700, 0, 64 * 1024, 64, SECT_4K | SPI_NOR_HAS_LOCK) },
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 5bee7c8da4dc..8c06a28a90de 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -861,7 +861,7 @@ int spi_nor_wait_till_ready(struct spi_nor *nor)
> *
> * Return: 0 on success, -errno otherwise.
> */
> -static int spi_nor_write_sr(struct spi_nor *nor, const u8 *sr, size_t len)
> +int spi_nor_write_sr(struct spi_nor *nor, const u8 *sr, size_t len)
> {
> int ret;
>
> diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
> index 0a775a7b5606..16b350e1d865 100644
> --- a/drivers/mtd/spi-nor/core.h
> +++ b/drivers/mtd/spi-nor/core.h
> @@ -430,6 +430,7 @@ void spi_nor_unlock_and_unprep(struct spi_nor *nor);
> int spi_nor_sr1_bit6_quad_enable(struct spi_nor *nor);
> int spi_nor_sr2_bit1_quad_enable(struct spi_nor *nor);
> int spi_nor_sr2_bit7_quad_enable(struct spi_nor *nor);
> +int spi_nor_write_sr(struct spi_nor *nor, const u8 *sr, size_t len);
>
> int spi_nor_xread_sr(struct spi_nor *nor, u8 *sr);
> ssize_t spi_nor_read_data(struct spi_nor *nor, loff_t from, size_t len,
> --
> 2.20.1
>

\
 
 \ /
  Last update: 2020-11-28 23:39    [W:0.097 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site