[U-Boot] [PATCH v2 02/12] dm: device: add function device_get_first_child_by_uclass_id()

[Simon Glass]

Hi Przemyslaw,

On 3 March 2015 at 09:24, Przemyslaw Marczak <p.marczak at samsung.com> wrote:
>
> To implement functionality for devices connected by some external
> interface, sometimes there is need to implement more then one,
> and different uclass type drivers.
>
> But only one i2c/spi dm chip can exists, per each bus i2c address
> or spi select. Then, it seems to be useful, to get the child device
> by uclass type, for the parent with known chip address.
>
> So, this change will be useful for the pmic case:
> |- i2c bus
>   '- pmic i2c chip (parent)
>     '- uclass regulator (child 1)
>     '- uclass charger (child 2)
>
> This will allow to get the regulator or charger device if knows only parent
> i2c/spi address.
>
> Signed-off-by: Przemyslaw Marczak <p.marczak at samsung.com>
> ---
> Changes V2:
> - new commit
> ---
>  drivers/core/device.c | 15 +++++++++++++++
>  include/dm/device.h   | 16 ++++++++++++++++
>  2 files changed, 31 insertions(+)
>
> diff --git a/drivers/core/device.c b/drivers/core/device.c
> index 73c3e07..76b22cf 100644
> --- a/drivers/core/device.c
> +++ b/drivers/core/device.c
> @@ -397,6 +397,21 @@ int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
>         return -ENODEV;
>  }
>
> +int device_get_first_child_by_uclass_id(struct udevice *parent, int uclass_id,

Can you please use the enum here instead of int?

>
> +                                       struct udevice **devp)
> +{
> +       struct udevice *dev;
> +
> +       *devp = NULL;
> +
> +       list_for_each_entry(dev, &parent->child_head, sibling_node) {
> +               if (dev->driver->id == uclass_id)
> +                       return device_get_device_tail(dev, 0, devp);
> +       }
> +
> +       return -ENODEV;
> +}
> +
>  int device_get_child_by_of_offset(struct udevice *parent, int seq,
>                                   struct udevice **devp)
>  {
> diff --git a/include/dm/device.h b/include/dm/device.h
> index 7a48eb8..9f0d6ce 100644
> --- a/include/dm/device.h
> +++ b/include/dm/device.h
> @@ -335,6 +335,22 @@ int device_get_child_by_of_offset(struct udevice *parent, int seq,
>                                   struct udevice **devp);
>
>  /**
> + * device_get_first_child_by_uclass_id() - Get the first child device based
> + *                                         on UCLASS_ID
> + *
> + * Locates a child device by its uclass id.
> + *
> + * The device is probed to activate it ready for use.
> + *
> + * @parent: Parent device
> + * @uclass_id: child uclass id
> + * @devp: Returns pointer to device if found, otherwise this is set to NULL
> + * @return 0 if OK, -ve on error
> + */
> +int device_get_first_child_by_uclass_id(struct udevice *parent, int uclass_id,
> +                                       struct udevice **devp);
> +
> +/**
>   * device_find_first_child() - Find the first child of a device
>   *
>   * @parent: Parent device to search
> --
> 1.9.1
>

Regards,
Simon