Re: [PATCH 03/11] mux: consumer.h: Add MUX_USB_* state constant defines

[Hans de Goede]

Hi,

On 02-09-17 12:10, Andy Shevchenko wrote:
> On Sat, Sep 2, 2017 at 12:48 AM, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> > Add MUX_USB_* state constant defines, which can be used by USB
> > device/host and Type-C polarity/role/altmode mux drivers and consumers
> > to ensure that they agree on the meaning of the mux_control_select()
> > state argument.
>
> > +/*
> > + * Mux state values for USB muxes, used for both USB device/host role muxes
> > + * as well as for Type-C polarity/role/altmode muxes.
> > + *
> > + * MUX_USB_POLARITY_INV may be or-ed together with any other mux-state as
> > + * inverted-polarity (Type-C plugged in upside down) can happen with any
> > + * other mux-state.
> > + */
> > +#define MUX_USB_POLARITY_INV   BIT(0)   /* Polarity inverted bit */
> > +#define MUX_USB_NONE           (1 << 1) /* Mux open / not connected */
> > +#define MUX_USB_DEVICE         (2 << 1) /* USB device mode */
> > +#define MUX_USB_HOST           (3 << 1) /* USB host mode */
> > +#define MUX_USB_HOST_AND_DP_SRC        (4 << 1) /* USB host + 2 lanes Display Port */
> > +#define MUX_USB_DP_SRC         (5 << 1) /* 4 lanes Display Port source */
> > +#define MUX_USB_STATES         (6 << 1)
>
> I would put OR'ed bits higher.
>
> Like allocate 4 (8) bits for states and start special flags from bit
> 8 and so on.

That is not an option because the mux framework expects a mux to declare
how much states it has (which is where the MUX_USB_STATES define comes in)
and any attemp to set a state higher then max_states will return with
-EINVAL.

Regards,

Hans