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

Guenter Roeck
2017-09-02T15:00:03Z

On 09/01/2017 02:48 PM, Hans de Goede 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.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> include/linux/mux/consumer.h | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/include/linux/mux/consumer.h b/include/linux/mux/consumer.h
> index 912dd48a3a5d..e3ec9b4db962 100644
> --- a/include/linux/mux/consumer.h
> +++ b/include/linux/mux/consumer.h
> @@ -15,6 +15,22 @@
>
> #include <linux/compiler.h>
>
> +/*
> + * 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 */

Why BIT(0) but (1 << 1) and so on ?

Guenter

> +#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)
> +
> struct device;
> struct mux_control;
>
>