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

Hans de Goede
2017-09-02T12:00:00Z

Hi,

On 02-09-17 12:10, Andy Shevchenko wrote:
> On Sat, Sep 2, 2017 at 12:48 AM, Hans de Goede <hdegoede@redhat.com> 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