@@ -55,6 +55,22 @@ contain the following properties.
chip select active high
- spi-3wire - (optional) Empty property indicating device requires
+- spi-tmax-nbits - (optional) Max number of bits slave will use for
+- spi-rmax-nbits - (optional) Max number of bits slave will use for
+So if for example the slave has 4 wires for writting and 2 wires for reading,
+and the spi-tx/rx-nbits property should be set as follows:
+spi-tmax-nbits = <4>;
+spi-rmax-nbits = <2>;
+Now the value that spi-tmax-nbits and spi-rmax-nbits can receive is only
+1(single), 2(dual) and 4(quad). If you don't set spi-tmax-nbits or spi-rmax-nbits,
+spi_device mode will be set in single(1 wire) as default. Another point, if
+property:spi-3wire is set, spi-t/rmax-nbits is forbidden to set to <2 or 4>,
+otherwise, an errro will return.
If a gpio chipselect is used for the SPI slave the gpio number will be passed
via the cs_gpio