xref: /freebsd/usr.sbin/spi/spi.8 (revision 4863a703958fe836b95ae2df8fd6a2f449157044)
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24.\" $FreeBSD$
25.\"
26.Dd August 21, 2020
27.Dt SPI 8
28.Os
29.Sh NAME
30.Nm spi
31.Nd communicate on SPI bus with slave devices
32.Sh SYNOPSIS
33.Nm
34.Op Fl A
35.Op Fl b
36.Op Fl L
37.Op Fl v
38.Op Fl C Ar command-bytes
39.Op Fl c Ar count
40.Op Fl d Cm r Ns | Ns Cm w Ns | Ns Cm rw
41.Op Fl f Ar device
42.Op Fl m Ar mode
43.Op Fl s Ar max-speed
44.Nm
45.Op Fl i
46.Op Fl v
47.Op Fl f Ar device
48.Nm
49.Op Fl h
50.Sh DESCRIPTION
51The
52.Nm
53utility can be used to perform raw data transfers
54.Pq read, write, or simultaneous read/write
55with devices on the SPI bus, via the
56.Xr spigen 4
57device.
58.Pp
59Each
60.Xr spigen 4
61device is associated with a specific
62.Dq chip select
63.Pq cs
64pin on the spibus, and therefore needs to be specified.
65If no device name is specified on the command line,
66.Nm
67assumes
68.Dq spigen0.0 .
69.Pp
70For more information on the spigen device, see
71.Xr spigen 4 .
72.Pp
73The options are as follows:
74.Bl -tag -width "-f device"
75.It Fl A
76Specifies ASCII mode.
77Both read and write data is input and output as
782-character hexadecimal values, optionally separated by white space,
79such as 00 01 02 etc.
80When combined with the
81.Fl b
82flag, the data on stdin remains a sequence of ASCII hexadecimal
83byte values, but the output reverts to binary mode.
84.It Fl b
85Binary
86.Pq output
87mode.
88Only has an effect when
89.Fl A
90has been specified.
91Reverts the output back to binary
92.Pq rather than ASCII ,
93while leaving the input format as-is.
94Use in combination with
95.Fl A
96to allow using something like
97.Dq echo
98to pass hexadecimal values to the SPI device, but output the received data
99on stdout as binary.
100.It Fl C Ar command-bytes
101Sends one or more command bytes,
102skipping any bytes read-in during the transfer.
103The byte values should be specified as a quoted parameter, similar to the
104format for data on stdin for
105.Fl A ,
106that is, 2 character hexadecimal values, optionally separated by white space.
107An SPI device will typically require that a command be sent, followed by
108bytes of data.
109You can use this option to send the command without receiving any data bytes
110during the command sequence.
111.It Fl c Ar count
112The total number of bytes to transfer as a decimal integer.
113If a write or a read/write transaction is being performed, and fewer than
114this number of bytes are read in from stdin, the remaining bytes will be
115sent with a value of
116.Dq 0 .
117If the length can be determined from the input file size, you can use a
118.Ar count
119value of
120.Dq -1
121to base the transfer on the input file's size.
122.It Fl d Cm r Ns | Ns Cm w Ns | Ns Cm rw
123Transfer direction: Use
124.Cm r
125for read,
126.Cm w
127for write, and
128.Cm rw
129for simultaneous read and write.
130.It Fl f Ar device
131SPI device to use
132.Pq default is Pa /dev/spigen0 .
133.It Fl h
134Print help text to stderr, explaining the command line options.
135.It Fl i
136Displays information about the SPI device to stderr.
137Whenever this flag is specified, no data is read or written, and the mode
138and clock speed are not changed.
139.It Fl L
140LSB bit order.
141The default is MSB, i.e., the highest order bit is
142transmitted first.
143Specifying
144.Fl L
145caused the LSB to be transmitted and read first.
146.It Fl m Cm 0 Ns | Ns Cm 1 Ns | Ns Cm 2 Ns | Ns Cm 3
147SPI mode, 0 through 3.
148This defines the clock phase and timing with respect to reading and writing
149data, as per the SPI specification.
150.It Fl s Ar speed
151Specify the maximum speed, in Hz, for the SPI clock.
152The bus will operate at its highest available speed which does not
153exceed this maximum.
154.It Fl v
155Specifies Verbose mode.
156Diagnostics and information are written to stderr.
157You can specify
158.Fl v
159more than once to increase verbosity.
160.El
161.Sh EXAMPLES
162Here are a few examples of using the spi utility:
163.Bl -bullet
164.It
165Get information about the default SPI device
166.Bd -literal
167spi -i
168.Ed
169.It
170Set the maximum clock speed to 200Khz and the mode to 3 on spigen0.1, but do
171not transmit nor receive any data
172.Bd -literal
173spi -f spigen0.1 -s 200000 -m 3
174.Ed
175.It
176Send a command sequence consisting of 2 bytes, and read 2 additional bytes
177from the SPI device, using the current mode and speed on the default device
178.Bd -literal
179spi -d r -C "00 01" -c 2
180.Ed
181.It
182Transmit a byte value of 5, and receive 2 bytes, displaying their values as
1832-byte ASCII hexadecimal, with mode 2, and a maximum clock speed of 500khz.
184.Bd -literal
185echo "05" | spi -A -d rw -m 2 -s 500000 -c 2
186.Ed
187.It
188Send a binary file, and output the SPI result through
189.Xr od 1
190as hexadecimal bytes, using the current maximum clock speed and SPI mode.
191.Bd -literal
192spi -d rw -c -1 <input_file.bin | od -An -t x1
193.Ed
194.It
195Send 2 bytes of data, receive a total of 4 bytes, and output the SPI result
196as binary data, piped through
197.Xr od 1 ,
198displaying it as two hexadecimal unsigned short integer values.
199.Bd -literal
200echo "00 01" | spi -A -b -d rw -c 4 | od -t x2
201.Ed
202.It
203Query the manufacturer ID and size from a standard spiflash device, by
204sending the command byte 0x9f and displaying the 3-byte reply in ASCII hex.
205.Bd -literal
206spi -f spigen0.0 -m 0 -s 1000000 -d r -c 3 -A -C 9f
207.Ed
208.El
209.Sh SEE ALSO
210.Xr spigen 4
211.Sh HISTORY
212The
213.Nm
214utility
215appeared in
216.Fx 11.3 .
217