[RFC,2/6] mmc: block: set fwnode of disk devices

Set fwnode of disk devices to 'block', 'boot0' and 'boot1' subnodes of
the mmc-card. This is done in preparation for having the eMMC act as
NVMEM provider.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
 drivers/mmc/core/block.c | 8 ++++++++
 1 file changed, 8 insertions(+)

On Thu, 20 Jul 2023 at 00:02, Daniel Golle <daniel@makrotopia.org> wrote:
>
> Set fwnode of disk devices to 'block', 'boot0' and 'boot1' subnodes of
> the mmc-card. This is done in preparation for having the eMMC act as
> NVMEM provider.

Sorry, but I don't quite understand what you are trying to do here.
Maybe you should re-order the patches in the series so it becomes
clear why this is needed?

Moreover, I don't see any DT docs being updated as a part of the
series, which looks like it is needed too. That would also help to
understand what you are proposing, I think.

>
> Signed-off-by: Daniel Golle <daniel@makrotopia.org>
> ---
>  drivers/mmc/core/block.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index f701efb1fa785..fc1a9f31bd253 100644
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@ -2413,6 +2413,8 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
>                                               int area_type,
>                                               unsigned int part_type)
>  {
> +       struct fwnode_handle *fwnode;
> +       struct device *ddev;
>         struct mmc_blk_data *md;
>         int devidx, ret;
>         char cap_str[10];
> @@ -2509,6 +2511,12 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
>
>         blk_queue_write_cache(md->queue.queue, cache_enabled, fua_enabled);
>
> +       ddev = disk_to_dev(md->disk);
> +       fwnode = device_get_named_child_node(subname ? md->parent->parent :
> +                                                      md->parent,
> +                                            subname ? subname : "block");
> +       ddev->fwnode = fwnode;
> +
>         string_get_size((u64)size, 512, STRING_UNITS_2,
>                         cap_str, sizeof(cap_str));
>         pr_info("%s: %s %s %s%s\n",

Kind regards
Uffe

Hi Ulf,

thank you for reviewing and suggesting ways to improve this series!

On Mon, Aug 07, 2023 at 03:48:31PM +0200, Ulf Hansson wrote:
> On Thu, 20 Jul 2023 at 00:02, Daniel Golle <daniel@makrotopia.org> wrote:
> >
> > Set fwnode of disk devices to 'block', 'boot0' and 'boot1' subnodes of
> > the mmc-card. This is done in preparation for having the eMMC act as
> > NVMEM provider.
> 
> Sorry, but I don't quite understand what you are trying to do here.
> Maybe you should re-order the patches in the series so it becomes
> clear why this is needed?
> 
> Moreover, I don't see any DT docs being updated as a part of the
> series, which looks like it is needed too. That would also help to
> understand what you are proposing, I think.

I've prepared a tree on Github which now also includes commits adding
dt-bindings for block devices and partitions, so they can be referenced
as nvmem-cells provider.

The dt-schema addition supposedly explaining this specific patch:

https://github.com/dangowrt/linux/commit/b399a758f0e1c444ae9443dc80902a30de54af09

The whole tree:

https://github.com/dangowrt/linux/commits/for-nvmem-next

Most comments have been addressed, however, I still depend on using
either a class_interface *or* adding calls to add/remove the NVMEM
representation of a block device to block/genhd.c as well as
block/partitions/core.c, simply because afaik there isn't any better
way for in-kernel users of block devices to be notified about the
creation or removal of a block device.

Cheers


Daniel

> 
> >
> > Signed-off-by: Daniel Golle <daniel@makrotopia.org>
> > ---
> >  drivers/mmc/core/block.c | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> > index f701efb1fa785..fc1a9f31bd253 100644
> > --- a/drivers/mmc/core/block.c
> > +++ b/drivers/mmc/core/block.c
> > @@ -2413,6 +2413,8 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
> >                                               int area_type,
> >                                               unsigned int part_type)
> >  {
> > +       struct fwnode_handle *fwnode;
> > +       struct device *ddev;
> >         struct mmc_blk_data *md;
> >         int devidx, ret;
> >         char cap_str[10];
> > @@ -2509,6 +2511,12 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
> >
> >         blk_queue_write_cache(md->queue.queue, cache_enabled, fua_enabled);
> >
> > +       ddev = disk_to_dev(md->disk);
> > +       fwnode = device_get_named_child_node(subname ? md->parent->parent :
> > +                                                      md->parent,
> > +                                            subname ? subname : "block");
> > +       ddev->fwnode = fwnode;
> > +
> >         string_get_size((u64)size, 512, STRING_UNITS_2,
> >                         cap_str, sizeof(cap_str));
> >         pr_info("%s: %s %s %s%s\n",
> 
> Kind regards
> Uffe

On Tue, 8 Aug 2023 at 03:02, Daniel Golle <daniel@makrotopia.org> wrote:
>
> Hi Ulf,
>
> thank you for reviewing and suggesting ways to improve this series!
>
> On Mon, Aug 07, 2023 at 03:48:31PM +0200, Ulf Hansson wrote:
> > On Thu, 20 Jul 2023 at 00:02, Daniel Golle <daniel@makrotopia.org> wrote:
> > >
> > > Set fwnode of disk devices to 'block', 'boot0' and 'boot1' subnodes of
> > > the mmc-card. This is done in preparation for having the eMMC act as
> > > NVMEM provider.
> >
> > Sorry, but I don't quite understand what you are trying to do here.
> > Maybe you should re-order the patches in the series so it becomes
> > clear why this is needed?
> >
> > Moreover, I don't see any DT docs being updated as a part of the
> > series, which looks like it is needed too. That would also help to
> > understand what you are proposing, I think.
>
> I've prepared a tree on Github which now also includes commits adding
> dt-bindings for block devices and partitions, so they can be referenced
> as nvmem-cells provider.
>
> The dt-schema addition supposedly explaining this specific patch:
>
> https://github.com/dangowrt/linux/commit/b399a758f0e1c444ae9443dc80902a30de54af09
>
> The whole tree:
>
> https://github.com/dangowrt/linux/commits/for-nvmem-next

Thanks for sharing. However, allow people to review, I suggest you
post a new version with the updated DT bindings included.

The point is, we really need confirmation from the DT maintainers -
otherwise this is simply a no go.

>
> Most comments have been addressed, however, I still depend on using
> either a class_interface *or* adding calls to add/remove the NVMEM
> representation of a block device to block/genhd.c as well as
> block/partitions/core.c, simply because afaik there isn't any better
> way for in-kernel users of block devices to be notified about the
> creation or removal of a block device.

Okay, so that needs further discussions then. I will try to chim in.

[...]

Kind regards
Uffe