Lines Matching +full:data +full:- +full:bus

21 .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 .Bd -ragged -offset indent
45 .Bd -literal -offset indent
51 driver provides direct access to a slave device on the SPI bus.
54 device is associated with a single chip-select
55 line on the bus, and all I/O performed through that instance is done
56 with that chip-select line asserted.
58 SPI data transfers are inherently bi-directional; there are no separate
60 When commands and data are sent to a device, data also comes back from
61 the device, although in some cases the data may not be useful (or even
63 Likewise on a read operation, whatever data is in the buffer at the start
75 .Bl -tag -width indent
77 Transfer a command and optional associated data to/from the device,
82 to zero if there is no data associated with the command.
83 .Bd -literal
90 Transfer a command and optional associated data to/from the device.
91 The buffers for the transfer are a previously-mmap'd region.
92 The length of the command and data within that region are described by the
100 is non-zero, the data appears in the memory region immediately
104 .Bd -literal
111 Get the maximum clock speed (bus frequency in Hertz) to be used
114 Set the maximum clock speed (bus frequency in Hertz) to be used
118 The actual bus frequency may be lower due to hardware limitations
119 of the SPI bus controller device.
136 .Bl -tag -width indent
142 The maximum bus frequency to use when communicating with this device.
143 Actual bus speed may be lower, depending on the capabilities of the SPI
146 The chip-select number to assert when performing I/O for this device.
149 The SPI mode (0-3) to use when communicating with this device.
155 of the SPI bus controller node.
161 The most commonly-used ones are documented below.
166 .Bl -tag -width indent
171 .It Va spi-max-frequency
172 The maximum bus frequency to use when communicating with this slave device.
173 Actual bus speed may be lower, depending on the capabilities of the SPI
180 .Bl -tag -width indent
181 .It Va spi-cpha
184 .It Va spi-cpol
187 .It Va spi-cs-high
191 .Bl -tag -width -compact