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

Hans de Goede
2017-09-02T15:59:24Z

Hi,

On 02-09-17 16:59, Guenter Roeck wrote:
> 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 ?

Because the polarity can be or-ed together with any of the other options.
Each option can be selected normal and inverted polarity (connector
inserted upside down).

Regards,

Hans

>> +#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;
>>
>