> -----Original Message----- > From: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > Sent: Friday, November 27, 2020 4:24 PM > To: Ardelean, Alexandru <alexandru.Ardelean@xxxxxxxxxx> > Cc: linux-spi <linux-spi@xxxxxxxxxxxxxxx>; devicetree > <devicetree@xxxxxxxxxxxxxxx>; Linux Kernel Mailing List <linux- > kernel@xxxxxxxxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; Mark Brown > <broonie@xxxxxxxxxx>; Bogdan, Dragos <Dragos.Bogdan@xxxxxxxxxx> > Subject: Re: [PATCH v3 2/3] spi: Add SPI_NO_TX/RX support > > 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 Hmm, in a way this could make sense for some SPIDEVs as well, to set these flags and get an error if they try to TX with the NO_TX flag set. Not really sure about this. Initially I mechanically added these here as an inertia to the previous patch which is just unifying the headers. Any other opinions? Thoughts? Mark? > > > > 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
