Re: [PATCH v3 2/3] spi: Add SPI_NO_TX/RX support

From: Andy Shevchenko
Date: Fri Nov 27 2020 - 09:22:54 EST


On Fri, Nov 27, 2020 at 4:22 PM Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
> On Fri, Nov 27, 2020 at 3:08 PM Alexandru Ardelean
> <alexandru.ardelean@xxxxxxxxxx> wrote:

...

> > --- a/include/uapi/linux/spi/spi.h
> > +++ b/include/uapi/linux/spi/spi.h
> > @@ -43,5 +43,7 @@
> > #define SPI_TX_OCTAL 0x2000 /* transmit with 8 wires */
> > #define SPI_RX_OCTAL 0x4000 /* receive with 8 wires */
> > #define SPI_3WIRE_HIZ 0x8000 /* high impedance turnaround */
> > +#define SPI_NO_TX 0x10000 /* no transmit wire */
> > +#define SPI_NO_RX 0x20000 /* no receive wire */
>
> Is it really material for uAPI?
> Perhaps we may have something like
> SPI_MODE_USER_MASK in uAPI and
> in internal headers
>
> SPI_MODE_KERNEL_MASK with
> static_assert(_USER_MASK & _KERNEL_MASK); // check conditional
>
> ?

And logically start bits for the kernel from the end (31, 30, ...).

--
With Best Regards,
Andy Shevchenko