[PATCH V3] mtd: move support for struct flash_platform_data into m25p80

[Brian Norris]

Hi Rafal,

On Sun, Sep 28, 2014 at 10:36:54PM +0200, Rafał Miłecki wrote:
> This "type" seems to be an extra hint for m25p80 about the flash. Some
> archs register flash_platform_data with "name" set to "m25p80" and then
> with a real flash name set in "type". It seems to be a trick specific
> to the m25p80 so let's move it out of spi-nor.
> Btw switch to the spi_nor_match_id instead of iterating spi_nor_ids.
> 
> Signed-off-by: Rafał Miłecki <zajec5 at gmail.com>
> ---
> V2: Comment usage of data->type
>     Set mtd.name in m25p80
> V3: Fix "respect" spelling in the comment
> 
> Brian: do you think this comment about "name" and "type" is clear
> enough now? If so, could you pick this patch, please?

I think the comments and patch look good now.

Unfortunately, I've delayed this a bit long, and in the meantime, we
have another issue cropping up here that may cause conflicts:

  http://lists.infradead.org/pipermail/linux-mtd/2014-September/055323.html

But anyway, I think his patch set is not quite ready, and this patch may
get us in a better position to resolve his, so:

Applied to l2-mtd.git.

Ben, please base your work on l2-mtd.git/master. If we need to get your
patch #1 into stable, then we can mark this patch as a dependency, I
think.

Brian

> ---
>  drivers/mtd/devices/m25p80.c  | 22 ++++++++++++++++++++--
>  drivers/mtd/spi-nor/spi-nor.c | 28 +---------------------------
>  2 files changed, 21 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
> index ed7e0a1b..dcda628 100644
> --- a/drivers/mtd/devices/m25p80.c
> +++ b/drivers/mtd/devices/m25p80.c
> @@ -193,11 +193,14 @@ static int m25p_probe(struct spi_device *spi)
>  {
>  	struct mtd_part_parser_data	ppdata;
>  	struct flash_platform_data	*data;
> +	const struct spi_device_id *id = NULL;
>  	struct m25p *flash;
>  	struct spi_nor *nor;
>  	enum read_mode mode = SPI_NOR_NORMAL;
>  	int ret;
>  
> +	data = dev_get_platdata(&spi->dev);
> +
>  	flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
>  	if (!flash)
>  		return -ENOMEM;
> @@ -223,11 +226,26 @@ static int m25p_probe(struct spi_device *spi)
>  		mode = SPI_NOR_QUAD;
>  	else if (spi->mode & SPI_RX_DUAL)
>  		mode = SPI_NOR_DUAL;
> -	ret = spi_nor_scan(nor, spi_get_device_id(spi), mode);
> +
> +	if (data && data->name)
> +		flash->mtd.name = data->name;
> +
> +	/* For some (historical?) reason many platforms provide two different
> +	 * names in flash_platform_data: "name" and "type". Quite often name is
> +	 * set to "m25p80" and then "type" provides a real chip name.
> +	 * If that's the case, respect "type" and ignore a "name".
> +	 */
> +	if (data && data->type)
> +		id = spi_nor_match_id(data->type);
> +
> +	/* If we didn't get name from platform, simply use "modalias". */
> +	if (!id)
> +		id = spi_get_device_id(spi);
> +
> +	ret = spi_nor_scan(nor, id, mode);
>  	if (ret)
>  		return ret;
>  
> -	data = dev_get_platdata(&spi->dev);
>  	ppdata.of_node = spi->dev.of_node;
>  
>  	return mtd_device_parse_register(&flash->mtd, NULL, &ppdata,
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 11459f6..ae16aa2 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -915,7 +915,6 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id,
>  			enum read_mode mode)
>  {
>  	struct flash_info		*info;
> -	struct flash_platform_data	*data;
>  	struct device *dev = nor->dev;
>  	struct mtd_info *mtd = nor->mtd;
>  	struct device_node *np = dev->of_node;
> @@ -926,28 +925,6 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id,
>  	if (ret)
>  		return ret;
>  
> -	/* Platform data helps sort out which chip type we have, as
> -	 * well as how this board partitions it.  If we don't have
> -	 * a chip ID, try the JEDEC id commands; they'll work for most
> -	 * newer chips, even if we don't recognize the particular chip.
> -	 */
> -	data = dev_get_platdata(dev);
> -	if (data && data->type) {
> -		const struct spi_device_id *plat_id;
> -
> -		for (i = 0; i < ARRAY_SIZE(spi_nor_ids) - 1; i++) {
> -			plat_id = &spi_nor_ids[i];
> -			if (strcmp(data->type, plat_id->name))
> -				continue;
> -			break;
> -		}
> -
> -		if (i < ARRAY_SIZE(spi_nor_ids) - 1)
> -			id = plat_id;
> -		else
> -			dev_warn(dev, "unrecognized id %s\n", data->type);
> -	}
> -
>  	info = (void *)id->driver_data;
>  
>  	if (info->jedec_id) {
> @@ -985,11 +962,8 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id,
>  		write_sr(nor, 0);
>  	}
>  
> -	if (data && data->name)
> -		mtd->name = data->name;
> -	else
> +	if (!mtd->name)
>  		mtd->name = dev_name(dev);
> -
>  	mtd->type = MTD_NORFLASH;
>  	mtd->writesize = 1;
>  	mtd->flags = MTD_CAP_NORFLASH;