[PATCH] mtd:spi-nor: Add lock and unlock callback functions to struct spi_nor

[Brian Norris]

Hi Viet,

On Mon, Mar 16, 2015 at 01:15:14AM -0700, vndao at altera.com wrote:
> From: VIET NGA DAO <vndao at altera.com>
> 
> This patch introduces a properly-replaceable spi_nor callback that does
> flash specific lock and unlock. The existing code for spi_nor_lock and
> spi_nor_unlock is moved into their own functions which are stm_lock and
> stm_unlock.

I'm curious; is this a complete ripoff of my code [1]? You haven't
credited my authorship at all. That's a big no-no. Typically you keep
the 'From:' and Signed-off-by of the original author if you're going to
modify/redistribute it. (Admittedly, I didn't provide the S-o-b on my
informal patch.)

Anyway, that's all fine this time, but please avoid doing this in the
future; I can fix up the authorship, etc., and apply it, if it gets an
Ack/Tested-by from one or more reviewers (e.g., you). BTW, I hope you at
least tested this, right?

Brian

[1] http://lists.infradead.org/pipermail/linux-mtd/2015-March/058301.html

> Signed-off-by: VIET NGA DAO <vndao at altera.com>
> ---
>  drivers/mtd/spi-nor/spi-nor.c | 56 ++++++++++++++++++++++++++++---------------
>  include/linux/mtd/spi-nor.h   |  4 ++++
>  2 files changed, 41 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index b6a5a0c..43bb552 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -369,17 +369,13 @@ erase_err:
>  	return ret;
>  }
>  
> -static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> +static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
>  {
> -	struct spi_nor *nor = mtd_to_spi_nor(mtd);
> +	struct mtd_info *mtd = nor->mtd;
>  	uint32_t offset = ofs;
>  	uint8_t status_old, status_new;
>  	int ret = 0;
>  
> -	ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_LOCK);
> -	if (ret)
> -		return ret;
> -
>  	status_old = read_sr(nor);
>  
>  	if (offset < mtd->size - (mtd->size / 2))
> @@ -402,26 +398,18 @@ static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
>  				(status_old & (SR_BP2 | SR_BP1 | SR_BP0))) {
>  		write_enable(nor);
>  		ret = write_sr(nor, status_new);
> -		if (ret)
> -			goto err;
>  	}
>  
> -err:
> -	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
>  	return ret;
>  }
>  
> -static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> +static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
>  {
> -	struct spi_nor *nor = mtd_to_spi_nor(mtd);
> +	struct mtd_info *mtd = nor->mtd;
>  	uint32_t offset = ofs;
>  	uint8_t status_old, status_new;
>  	int ret = 0;
>  
> -	ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_UNLOCK);
> -	if (ret)
> -		return ret;
> -
>  	status_old = read_sr(nor);
>  
>  	if (offset+len > mtd->size - (mtd->size / 64))
> @@ -444,15 +432,41 @@ static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
>  				(status_old & (SR_BP2 | SR_BP1 | SR_BP0))) {
>  		write_enable(nor);
>  		ret = write_sr(nor, status_new);
> -		if (ret)
> -			goto err;
>  	}
>  
> -err:
> +	return ret;
> +}
> +
> +static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> +{
> +	struct spi_nor *nor = mtd_to_spi_nor(mtd);
> +	int ret;
> +
> +	ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_LOCK);
> +	if (ret)
> +		return ret;
> +
> +	ret = nor->flash_lock(nor, ofs, len);
> +
>  	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_UNLOCK);
>  	return ret;
>  }
>  
> +static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> +{
> +	struct spi_nor *nor = mtd_to_spi_nor(mtd);
> +	int ret;
> +
> +	ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_UNLOCK);
> +	if (ret)
> +		return ret;
> +
> +	ret = nor->flash_unlock(nor, ofs, len);
> +
> +	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
> +	return ret;
> +}
> +
>  /* Used when the "_ext_id" is two bytes at most */
>  #define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags)	\
>  	((kernel_ulong_t)&(struct flash_info) {				\
> @@ -1045,6 +1059,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
>  
>  	/* nor protection support for STmicro chips */
>  	if (JEDEC_MFR(info) == CFI_MFR_ST) {
> +		nor->flash_lock = stm_lock;
> +		nor->flash_unlock = stm_unlock;
> +	}
> +	if (nor->flash_lock && nor->flash_unlock) {
>  		mtd->_lock = spi_nor_lock;
>  		mtd->_unlock = spi_nor_unlock;
>  	}
> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> index 4720b86..e4e73d5 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -155,6 +155,8 @@ enum spi_nor_option_flags {
>   * @write:		[DRIVER-SPECIFIC] write data to the SPI NOR
>   * @erase:		[DRIVER-SPECIFIC] erase a sector of the SPI NOR
>   *			at the offset @offs
> + * @lock:		[FLASH-SPECIFIC] lock a region of the SPI NOR
> + * @unlock:		[FLASH-SPECIFIC] unlock a region of the SPI NOR
>   * @priv:		the private data
>   */
>  struct spi_nor {
> @@ -188,6 +190,8 @@ struct spi_nor {
>  	void (*write)(struct spi_nor *nor, loff_t to,
>  			size_t len, size_t *retlen, const u_char *write_buf);
>  	int (*erase)(struct spi_nor *nor, loff_t offs);
> +	int (*flash_lock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
> +	int (*flash_unlock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
>  
>  	void *priv;
>  };
> -- 
> 1.7.11.GIT
>