[U-Boot] [PATCH v2 1/2] misc: uclass: Add enable/disable function

[Simon Glass <sjg@chromium.org>]

Hi Mario,

On 27 April 2018 at 06:52, Mario Six <mario.six@gdsys.cc> wrote:
> Add generic enable/disable function to the misc uclass.
>
> Signed-off-by: Mario Six <mario.six@gdsys.cc>
> ---
>
> v1 -> v2:
> * Merged the two functions into one function
> * Explained the semantics of enabling/disabling more throughly
>
> ---
>  drivers/misc/misc-uclass.c | 10 ++++++++++
>  include/misc.h             | 25 +++++++++++++++++++++++++
>  2 files changed, 35 insertions(+)
>
> diff --git a/drivers/misc/misc-uclass.c b/drivers/misc/misc-uclass.c
> index d9eea3dac5..0e3e0e8bf7 100644
> --- a/drivers/misc/misc-uclass.c
> +++ b/drivers/misc/misc-uclass.c
> @@ -56,6 +56,16 @@ int misc_call(struct udevice *dev, int msgid, void *tx_msg, int tx_size,
>         return ops->call(dev, msgid, tx_msg, tx_size, rx_msg, rx_size);
>  }
>
> +int misc_set_enabled(struct udevice *dev, bool val)
> +{
> +       const struct misc_ops *ops = device_get_ops(dev);
> +
> +       if (!ops->set_enabled)
> +               return -ENOSYS;
> +
> +       return ops->set_enabled(dev, val);
> +}
> +
>  UCLASS_DRIVER(misc) = {
>         .id             = UCLASS_MISC,
>         .name           = "misc",
> diff --git a/include/misc.h b/include/misc.h
> index 03ef55cdc8..04a4b65155 100644
> --- a/include/misc.h
> +++ b/include/misc.h
> @@ -58,6 +58,22 @@ int misc_ioctl(struct udevice *dev, unsigned long request, void *buf);
>  int misc_call(struct udevice *dev, int msgid, void *tx_msg, int tx_size,
>               void *rx_msg, int rx_size);
>
> +/*
> + * Enable or disable a device.
> + *
> + * The semantics of "disable" and "enable" should be understood here as
> + * activating or deactivating the device's primary function, hence a "disabled"
> + * device should be dormant, but still answer to commands and queries.
> + *
> + * A probed device may start in a disabled or enabled state, depending on the
> + * driver and hardware.

This makes be wonder whether we should have this as a concept
understood by the DM core. But perhaps not until we have more use
cases. So far I know of only display that needs this.

> + *
> + * @dev: the device to enable or disable.
> + * @val: the flag that tells the driver to either enable or disable the device.
> + * @return: 0 if OK, -ve on error
> + */
> +int misc_set_enabled(struct udevice *dev, bool val);
> +
>  /*
>   * struct misc_ops - Driver model Misc operations
>   *
> @@ -109,6 +125,15 @@ struct misc_ops {
>          */
>         int (*call)(struct udevice *dev, int msgid, void *tx_msg, int tx_size,
>                     void *rx_msg, int rx_size);
> +       /*
> +        * Enable or disable a device, optional.
> +        *
> +        * @dev: the device to enable.
> +        * @val: the flag that tells the driver to either enable or disable the
> +        *       device.
> +        * @return: 0 if OK, -ve on error

How about returning the old state (0 or 1)?

> +        */
> +       int (*set_enabled)(struct udevice *dev, bool val);
>  };
>
>  #endif /* _MISC_H_ */
> --
> 2.16.1
>

Regards,
Simon