[RFC 07/22] dm: blk: add UCLASS_PARTITION

[Simon Glass]

Hi Takahiro,

On Thu, 30 Sept 2021 at 23:03, AKASHI Takahiro
<takahiro.akashi at linaro.org> wrote:
>
> UCLASS_PARTITION device will be created as a child node of
> UCLASS_BLK device.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> ---
>  drivers/block/blk-uclass.c | 111 +++++++++++++++++++++++++++++++++++++
>  include/blk.h              |   9 +++
>  include/dm/uclass-id.h     |   1 +
>  3 files changed, 121 insertions(+)
>
> diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
> index 83682dcc181a..dd7f3c0fe31e 100644
> --- a/drivers/block/blk-uclass.c
> +++ b/drivers/block/blk-uclass.c
> @@ -12,6 +12,7 @@
>  #include <log.h>
>  #include <malloc.h>
>  #include <part.h>
> +#include <string.h>
>  #include <dm/device-internal.h>
>  #include <dm/lists.h>
>  #include <dm/uclass-internal.h>
> @@ -695,6 +696,44 @@ int blk_unbind_all(int if_type)
>         return 0;
>  }
>
> +int blk_create_partitions(struct udevice *parent)
> +{
> +       int part, count;
> +       struct blk_desc *desc = dev_get_uclass_plat(parent);
> +       struct disk_partition info;
> +       struct disk_part *part_data;
> +       char devname[32];
> +       struct udevice *dev;
> +       int ret;
> +
> +       if (!CONFIG_IS_ENABLED(PARTITIONS) ||
> +           !CONFIG_IS_ENABLED(HAVE_BLOCK_DEVICE))
> +               return 0;
> +
> +       /* Add devices for each partition */
> +       for (count = 0, part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
> +               if (part_get_info(desc, part, &info))
> +                       continue;
> +               snprintf(devname, sizeof(devname), "%s:%d", parent->name,
> +                        part);
> +
> +               ret = device_bind_driver(parent, "blk_partition",
> +                                        strdup(devname), &dev);
> +               if (ret)
> +                       return ret;
> +
> +               part_data = dev_get_uclass_plat(dev);
> +               part_data->partnum = part;
> +               part_data->gpt_part_info = info;
> +               count++;
> +
> +               device_probe(dev);
> +       }
> +       debug("%s: %d partitions found in %s\n", __func__, count, parent->name);

log_debug() and drop __func__

> +
> +       return 0;
> +}
> +
>  static int blk_post_probe(struct udevice *dev)
>  {
>         if (IS_ENABLED(CONFIG_PARTITIONS) &&
> @@ -713,3 +752,75 @@ UCLASS_DRIVER(blk) = {
>         .post_probe     = blk_post_probe,
>         .per_device_plat_auto   = sizeof(struct blk_desc),
>  };
> +
> +static ulong blk_part_read(struct udevice *dev, lbaint_t start,
> +                          lbaint_t blkcnt, void *buffer)
> +{

part_blk_read() so that it is clear that this takes a UCLASS_PARTITION
device, not a UCLASS_BLK

> +       struct udevice *parent;
> +       struct disk_part *part;
> +       const struct blk_ops *ops;
> +
> +       parent = dev_get_parent(dev);
> +       ops = blk_get_ops(parent);
> +       if (!ops->read)
> +               return -ENOSYS;
> +
> +       part = dev_get_uclass_plat(dev);
> +       start += part->gpt_part_info.start;
> +
> +       return ops->read(parent, start, blkcnt, buffer);
> +}
> +
> +static ulong blk_part_write(struct udevice *dev, lbaint_t start,
> +                           lbaint_t blkcnt, const void *buffer)
> +{
> +       struct udevice *parent;
> +       struct disk_part *part;
> +       const struct blk_ops *ops;
> +
> +       parent = dev_get_parent(dev);
> +       ops = blk_get_ops(parent);
> +       if (!ops->write)
> +               return -ENOSYS;
> +
> +       part = dev_get_uclass_plat(dev);
> +       start += part->gpt_part_info.start;
> +
> +       return ops->write(parent, start, blkcnt, buffer);
> +}
> +
> +static ulong blk_part_erase(struct udevice *dev, lbaint_t start,
> +                           lbaint_t blkcnt)
> +{
> +       struct udevice *parent;
> +       struct disk_part *part;
> +       const struct blk_ops *ops;
> +
> +       parent = dev_get_parent(dev);
> +       ops = blk_get_ops(parent);
> +       if (!ops->erase)
> +               return -ENOSYS;
> +
> +       part = dev_get_uclass_plat(dev);
> +       start += part->gpt_part_info.start;
> +
> +       return ops->erase(parent, start, blkcnt);
> +}
> +
> +static const struct blk_ops blk_part_ops = {
> +       .read   = blk_part_read,
> +       .write  = blk_part_write,
> +       .erase  = blk_part_erase,
> +};
> +
> +U_BOOT_DRIVER(blk_partition) = {
> +       .name           = "blk_partition",
> +       .id             = UCLASS_PARTITION,
> +       .ops            = &blk_part_ops,
> +};

Can you put this all in a separate part-uclass.c file? This too:

> +
> +UCLASS_DRIVER(partition) = {
> +       .id             = UCLASS_PARTITION,
> +       .per_device_plat_auto   = sizeof(struct disk_part),
> +       .name           = "partition",
> +};
> diff --git a/include/blk.h b/include/blk.h
> index 19bab081c2cd..3d883eb1db64 100644
> --- a/include/blk.h
> +++ b/include/blk.h
> @@ -366,6 +366,15 @@ int blk_create_devicef(struct udevice *parent, const char *drv_name,
>                        const char *name, int if_type, int devnum, int blksz,
>                        lbaint_t lba, struct udevice **devp);
>
> +/**
> + * blk_create_partitions - Create block devices for disk partitions
> + *
> + * Create UCLASS_PARTITION udevices for each of disk partitions in @parent
> + *
> + * @parent:    Whole disk device

UCLASS_BLK?

It is good to document the device types to avoid people getting confused later.

> + */
> +int blk_create_partitions(struct udevice *parent);
> +
>  /**
>   * blk_unbind_all() - Unbind all device of the given interface type
>   *
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> index e7edd409f307..30892d01ce13 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -80,6 +80,7 @@ enum uclass_id {
>         UCLASS_P2SB,            /* (x86) Primary-to-Sideband Bus */
>         UCLASS_PANEL,           /* Display panel, such as an LCD */
>         UCLASS_PANEL_BACKLIGHT, /* Backlight controller for panel */
> +       UCLASS_PARTITION,       /* Logical disk partition device */
>         UCLASS_PCH,             /* x86 platform controller hub */
>         UCLASS_PCI,             /* PCI bus */
>         UCLASS_PCI_EP,          /* PCI endpoint device */
> --
> 2.33.0
>

This is a new uclass so needs a sandbox test.

Regards,
Simon