Messages in this thread | | | Subject | Re: [PATCH 03/11] mux: consumer.h: Add MUX_USB_* state constant defines | From | Hans de Goede <> | Date | Sat, 2 Sep 2017 17:59:14 +0200 |
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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; >> >
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