[PATCH] mmc: add wp_grp_size node

[AngeloGioacchino Del Regno]

Il 01/11/23 16:49, Bo Ye ha scritto:
> From: "lin.gui" <lin.gui at mediatek.com>
> 
> Detail:
> Add node "wp_grp_size", corresponding to WP_GRP_SIZE
> (write protect group size) of eMMC's CSD register.
> 
> Scenario:
> The eMMC card can be set into write-protected mode to
> prevent data from being accidentally modified or deleted.
> Wp_grp_size (Write Protect Group Size) refers to an
> attribute of the eMMC card, used to manage write protection,
> and is the CSD register  [36:32] of the eMMC device.
> Wp_grp_size (Write Protect Group Size) indicates how many
> eMMC blocks are contained in each write protection group on the eMMC card.
> 
> Final rendered file:
> "/sys/class/mmc_host/mmc0/mmc0:0001/wp_grp_size"
> 
> Signed-off-by: lin.gui <lin.gui at mediatek.com>
> Change-Id: I73952dbde2db375ba918daadb3264380b7863096

The change-id tag means nothing upstream. Please remove.

Also, the recipients list doesn't look right. Please use scripts/get_maintainer.pl
to get the right recipients list, or your patch will be ignored.

> ---
>   drivers/mmc/core/mmc.c   | 16 +++++++++++++++-
>   include/linux/mmc/card.h |  2 ++
>   2 files changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 4a4bab9aa726..9b67e49a9e63 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -136,6 +136,17 @@ static void mmc_set_erase_size(struct mmc_card *card)
>   	mmc_init_erase(card);
>   }
>   
> +
> +static void mmc_set_wp_grp_size(struct mmc_card *card)
> +{
> +	if (card->ext_csd.erase_group_def & 1)
> +		card->wp_grp_size = card->ext_csd.hc_erase_size *
> +			card->ext_csd.raw_hc_erase_gap_size;
> +	else
> +		card->wp_grp_size = card->csd.erase_size *
> +			(card->csd.wp_grp_size + 1);
> +}
> +
>   /*
>    * Given a 128-bit response, decode to our card CSD structure.
>    */
> @@ -186,6 +197,7 @@ static int mmc_decode_csd(struct mmc_card *card)
>   		b = UNSTUFF_BITS(resp, 37, 5);
>   		csd->erase_size = (a + 1) * (b + 1);
>   		csd->erase_size <<= csd->write_blkbits - 9;
> +		csd->wp_grp_size = UNSTUFF_BITS(resp, 32, 5);
>   	}
>   
>   	return 0;
> @@ -791,6 +803,7 @@ MMC_DEV_ATTR(csd, "%08x%08x%08x%08x\n", card->raw_csd[0], card->raw_csd[1],
>   MMC_DEV_ATTR(date, "%02d/%04d\n", card->cid.month, card->cid.year);
>   MMC_DEV_ATTR(erase_size, "%u\n", card->erase_size << 9);
>   MMC_DEV_ATTR(preferred_erase_size, "%u\n", card->pref_erase << 9);
> +MMC_DEV_ATTR(wp_grp_size, "%u\n", card->wp_grp_size << 9);
>   MMC_DEV_ATTR(ffu_capable, "%d\n", card->ext_csd.ffu_capable);
>   MMC_DEV_ATTR(hwrev, "0x%x\n", card->cid.hwrev);
>   MMC_DEV_ATTR(manfid, "0x%06x\n", card->cid.manfid);
> @@ -851,6 +864,7 @@ static struct attribute *mmc_std_attrs[] = {
>   	&dev_attr_date.attr,
>   	&dev_attr_erase_size.attr,
>   	&dev_attr_preferred_erase_size.attr,
> +	&dev_attr_wp_grp_size.attr,
>   	&dev_attr_fwrev.attr,
>   	&dev_attr_ffu_capable.attr,
>   	&dev_attr_hwrev.attr,
> @@ -1759,7 +1773,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>   			mmc_set_erase_size(card);
>   		}
>   	}
> -
> +	mmc_set_wp_grp_size(card);
>   	/*
>   	 * Ensure eMMC user default partition is enabled
>   	 */
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index daa2f40d9ce6..62873ecc52f1 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -32,6 +32,7 @@ struct mmc_csd {
>   	unsigned int		r2w_factor;
>   	unsigned int		max_dtr;
>   	unsigned int		erase_size;		/* In sectors */
> +	unsigned int		wp_grp_size;
>   	unsigned int		read_blkbits;
>   	unsigned int		write_blkbits;
>   	unsigned int		capacity;
> @@ -304,6 +305,7 @@ struct mmc_card {
>   	unsigned int		eg_boundary;	/* don't cross erase-group boundaries */
>   	unsigned int		erase_arg;	/* erase / trim / discard */
>    	u8			erased_byte;	/* value of erased bytes */
> +	unsigned int		wp_grp_size; /* write group size in sectors */

There should be a tabulation before the comment, not a space.

Regards,
Angelo