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Diffstat (limited to 'static/netbsd/man9/spi.9')
| -rw-r--r-- | static/netbsd/man9/spi.9 | 171 |
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diff --git a/static/netbsd/man9/spi.9 b/static/netbsd/man9/spi.9 new file mode 100644 index 00000000..fe4a0bb4 --- /dev/null +++ b/static/netbsd/man9/spi.9 @@ -0,0 +1,171 @@ +.\" $NetBSD: spi.9,v 1.3 2025/10/10 18:36:17 brad Exp $ +.\" +.\" Copyright (c) 2019 The NetBSD Foundation +.\" All rights reserved. +.\" +.\" Written by Michael van Elst +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC +.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +.\" POSSIBILITY OF SUCH DAMAGE. +.\" +.Dd February 23, 2019 +.Dt SPI 9 +.Os +.Sh NAME +.Nm spi_configure , +.Nm spi_transfer , +.Nm spi_transfer_init , +.Nm spi_chunk_init , +.Nm spi_transfer_add , +.Nm spi_wait , +.Nm spi_done , +.Nm spi_send , +.Nm spi_sendv , +.Nm spi_recv , +.Nm spi_send_recv +.Nd Serial Peripheral Interface (SPI) kernel interface +.Sh SYNOPSIS +.In dev/spi/spivar.h +.Ft int +.Fo spi_configure +.Fa "struct spi_handle *sh" +.Fa "int mode" +.Fa "int speed" +.Fc +.Ft int +.Fo spi_transfer +.Fa "struct spi_handle *sh" +.Fa "struct spi_transfer *st" +.Fc +.Ft void +.Fo spi_transfer_init +.Fa "struct spi_transfer *st" +.Fc +.Ft void +.Fo spi_chunk_init +.Fa "struct spi_chunk *chunk" +.Fa "int cnt" +.Fa "const uint8_t *wptr" +.Fa "uint8_t *rptr" +.Fc +.Ft void +.Fo spi_transfer_add +.Fa "struct spi_transfer *st" +.Fa "struct spi_chunk *chunk" +.Fc +.Ft void +.Fo spi_wait +.Fa "struct spi_transfer *st" +.Fc +.Ft void +.Fo spi_done +.Fa "struct spi_transfer *st" +.Fa "int err" +.Fc +.Ft int +.Fo spi_recv +.Fa "struct spi_handle *sh" +.Fa "int cnt" +.Fa "uint8_t *data" +.Fc +.Ft int +.Fo spi_send +.Fa "struct spi_handle *sh" +.Fa "int cnt" +.Fa "const uint8_t *data" +.Fc +.Ft int +.Fo spi_sendv +.Fa "struct spi_handle *sh" +.Fa "struct iovec *iov" +.Fa "int iovcnt" +.Fc +.Ft int +.Fo spi_send_recv +.Fa "struct spi_handle *sh" +.Fa "int scnt" +.Fa "const uint8_t *snd" +.Fa "int rcnt" +.Fa "uint8_t *rcv" +.Fc +.Sh DESCRIPTION +SPI is a 4-wire synchronous full-duplex serial bus. +It is commonly used for connecting devices such as EEPROMs, +displays, and other types of integrated circuits. +The +.Nm spi +interface provides a means of communicating with SPI-connected devices. +.Sh FUNCTIONS +The following functions comprise the API provided to drivers of +SPI-connected devices. +.Pp +The +.Fa struct spi_handle +corresponding to the device is passed in the driver attachment. +.Bl -tag -width spi_transfer_init +.It Fn spi_configure "sh" "mode" "speed" +Sets mode and speed for subsequent communication with a SPI slave. +.It Fn spi_transfer "sh" "st" +Queue transfer to SPI controller. +.Fn spi_transfer +returns an errno value when the transfer couldn't be queued. +.It Fn spi_transfer_init "st" +Initialize a transfer structure. +.It Fn spi_chunk_init "chunk" "cnt" "wptr" rptr" +Initialize a chunk structure, each chunk corresponds to +a possibly bi-directional transfer where the same amount +of bytes is shifted in and out. +.It Fn spi_transfer_add "st" "chunk" +Append a chunk to transfer structure. +.It Fn spi_wait "st" +Wait for a transfer to complete. +When the transfer has failed for some reason, the field +.Va st->st_errno +is set to a non-zero value. +.It Fn spi_done "st" "err" +Called back machine-dependent backend to signal completion +of a transfer. +.El +.Pp +For simplicity there are convenience functions that combine +common operations. +These functions return an errno value when the transfer failed. +.Bl -tag -width spi_transfer_init +.It Fn spi_recv "sh" "cnt" "data" +Prepares a chunk for receiving data, queues a transfer and +waits for it to complete. +.It Fn spi_send "sh" "cnt" "data" +Prepares a chunk for sending data, queues a transfer and +waits for it to complete. +.It Fn spi_sendv "sh" "iov" "iovcnt" +Prepare and queue a scatter of chunks and wait for them to complete. +.It Fn spi_send_recv "sh" "scnt" "snd" "rcnt" "rcv" +Prepares two chunks for sending data first and then receiving +an answer, queues a transfer and waits for it to complete. +This is not a full-duplex operation. +.El +.Sh SEE ALSO +.Xr spi 4 +.Sh HISTORY +The +.Nm spi +API first appeared in +.Nx 4.0 . |