[v2] mmc: add wp_grp_size node

From: "lin.gui" <lin.gui@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@mediatek.com>
Signed-off-by: Bo Ye <bo.ye@mediatek.com>
---
Change in v2: 
-remove Change-Id
-replace space with tabulation
---
 drivers/mmc/core/mmc.c   | 16 +++++++++++++++-
 include/linux/mmc/card.h |  2 ++
 2 files changed, 17 insertions(+), 1 deletion(-)

On Mon, 18 Dec 2023 at 23:48, Bo Ye <bo.ye@mediatek.com> wrote:
>
> From: "lin.gui" <lin.gui@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@mediatek.com>
> Signed-off-by: Bo Ye <bo.ye@mediatek.com>

Applied for next, thanks!

Note that checkpatch complained about the patch (see below), but I
fixed it up this time.

WARNING: From:/Signed-off-by: email name mismatch: 'From: "lin.gui"
<lin.gui@mediatek.com>' != 'Signed-off-by: Lin Gui
<lin.gui@mediatek.com>'

Kind regards
Uffe



> ---
> Change in v2:
> -remove Change-Id
> -replace space with tabulation
> ---
>  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 705942edacc6..e0d72378ac77 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;
> @@ -790,6 +802,7 @@ 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);
> @@ -850,6 +863,7 @@ 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,
> @@ -1764,7 +1778,7 @@ 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 7b12eebc5586..b9c3c6303a22 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;
> @@ -306,6 +307,7 @@ 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 */
>
>         u32                     raw_cid[4];     /* raw card CID */
>         u32                     raw_csd[4];     /* raw card CSD */
> --
> 2.18.0
>