xref: /freebsd/usr.sbin/spi/spi.8 (revision cbb3ec25236ba72f91cbdf23f8b78b9d1af0cedf)
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24.Dd August 21, 2020
25.Dt SPI 8
26.Os
27.Sh NAME
28.Nm spi
29.Nd communicate on SPI bus with slave devices
30.Sh SYNOPSIS
31.Nm
32.Op Fl A
33.Op Fl b
34.Op Fl L
35.Op Fl v
36.Op Fl C Ar command-bytes
37.Op Fl c Ar count
38.Op Fl d Cm r Ns | Ns Cm w Ns | Ns Cm rw
39.Op Fl f Ar device
40.Op Fl m Ar mode
41.Op Fl s Ar max-speed
42.Nm
43.Op Fl i
44.Op Fl v
45.Op Fl f Ar device
46.Nm
47.Op Fl h
48.Sh DESCRIPTION
49The
50.Nm
51utility can be used to perform raw data transfers
52.Pq read, write, or simultaneous read/write
53with devices on the SPI bus, via the
54.Xr spigen 4
55device.
56.Pp
57Each
58.Xr spigen 4
59device is associated with a specific
60.Dq chip select
61.Pq cs
62pin on the spibus, and therefore needs to be specified.
63If no device name is specified on the command line,
64.Nm
65assumes
66.Dq spigen0.0 .
67.Pp
68For more information on the spigen device, see
69.Xr spigen 4 .
70.Pp
71The options are as follows:
72.Bl -tag -width "-f device"
73.It Fl A
74Specifies ASCII mode.
75Both read and write data is input and output as
762-character hexadecimal values, optionally separated by white space,
77such as 00 01 02 etc.
78When combined with the
79.Fl b
80flag, the data on stdin remains a sequence of ASCII hexadecimal
81byte values, but the output reverts to binary mode.
82.It Fl b
83Binary
84.Pq output
85mode.
86Only has an effect when
87.Fl A
88has been specified.
89Reverts the output back to binary
90.Pq rather than ASCII ,
91while leaving the input format as-is.
92Use in combination with
93.Fl A
94to allow using something like
95.Dq echo
96to pass hexadecimal values to the SPI device, but output the received data
97on stdout as binary.
98.It Fl C Ar command-bytes
99Sends one or more command bytes,
100skipping any bytes read-in during the transfer.
101The byte values should be specified as a quoted parameter, similar to the
102format for data on stdin for
103.Fl A ,
104that is, 2 character hexadecimal values, optionally separated by white space.
105An SPI device will typically require that a command be sent, followed by
106bytes of data.
107You can use this option to send the command without receiving any data bytes
108during the command sequence.
109.It Fl c Ar count
110The total number of bytes to transfer as a decimal integer.
111If a write or a read/write transaction is being performed, and fewer than
112this number of bytes are read in from stdin, the remaining bytes will be
113sent with a value of
114.Dq 0 .
115If the length can be determined from the input file size, you can use a
116.Ar count
117value of
118.Dq -1
119to base the transfer on the input file's size.
120.It Fl d Cm r Ns | Ns Cm w Ns | Ns Cm rw
121Transfer direction: Use
122.Cm r
123for read,
124.Cm w
125for write, and
126.Cm rw
127for simultaneous read and write.
128.It Fl f Ar device
129SPI device to use
130.Pq default is Pa /dev/spigen0 .
131.It Fl h
132Print help text to stderr, explaining the command line options.
133.It Fl i
134Displays information about the SPI device to stderr.
135Whenever this flag is specified, no data is read or written, and the mode
136and clock speed are not changed.
137.It Fl L
138LSB bit order.
139The default is MSB, i.e., the highest order bit is
140transmitted first.
141Specifying
142.Fl L
143caused the LSB to be transmitted and read first.
144.It Fl m Cm 0 Ns | Ns Cm 1 Ns | Ns Cm 2 Ns | Ns Cm 3
145SPI mode, 0 through 3.
146This defines the clock phase and timing with respect to reading and writing
147data, as per the SPI specification.
148.It Fl s Ar speed
149Specify the maximum speed, in Hz, for the SPI clock.
150The bus will operate at its highest available speed which does not
151exceed this maximum.
152.It Fl v
153Specifies Verbose mode.
154Diagnostics and information are written to stderr.
155You can specify
156.Fl v
157more than once to increase verbosity.
158.El
159.Sh EXAMPLES
160Here are a few examples of using the spi utility:
161.Bl -bullet
162.It
163Get information about the default SPI device
164.Bd -literal
165spi -i
166.Ed
167.It
168Set the maximum clock speed to 200Khz and the mode to 3 on spigen0.1, but do
169not transmit nor receive any data
170.Bd -literal
171spi -f spigen0.1 -s 200000 -m 3
172.Ed
173.It
174Send a command sequence consisting of 2 bytes, and read 2 additional bytes
175from the SPI device, using the current mode and speed on the default device
176.Bd -literal
177spi -d r -C "00 01" -c 2
178.Ed
179.It
180Transmit a byte value of 5, and receive 2 bytes, displaying their values as
1812-byte ASCII hexadecimal, with mode 2, and a maximum clock speed of 500khz.
182.Bd -literal
183echo "05" | spi -A -d rw -m 2 -s 500000 -c 2
184.Ed
185.It
186Send a binary file, and output the SPI result through
187.Xr od 1
188as hexadecimal bytes, using the current maximum clock speed and SPI mode.
189.Bd -literal
190spi -d rw -c -1 <input_file.bin | od -An -t x1
191.Ed
192.It
193Send 2 bytes of data, receive a total of 4 bytes, and output the SPI result
194as binary data, piped through
195.Xr od 1 ,
196displaying it as two hexadecimal unsigned short integer values.
197.Bd -literal
198echo "00 01" | spi -A -b -d rw -c 4 | od -t x2
199.Ed
200.It
201Query the manufacturer ID and size from a standard spiflash device, by
202sending the command byte 0x9f and displaying the 3-byte reply in ASCII hex.
203.Bd -literal
204spi -f spigen0.0 -m 0 -s 1000000 -d r -c 3 -A -C 9f
205.Ed
206.El
207.Sh SEE ALSO
208.Xr spigen 4
209.Sh HISTORY
210The
211.Nm
212utility
213appeared in
214.Fx 11.3 .
215