Lines Matching +full:full +full:- +full:custom
1 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
7 has low-level support for the CEC bus. Most hardware today will have
8 high-level CEC support where the hardware deals with driving the CEC bus,
13 What makes doing this so interesting is that since we have full control
17 Currently only the cec-gpio driver (when the CEC line is directly
18 connected to a pull-up GPIO line) and the AllWinner A10/A20 drm driver
23 now an ``error-inj`` file.
30 With ``cat error-inj`` you can see both the possible commands and the current
33 $ cat /sys/kernel/debug/cec/cec0/error-inj
36 # rx-clear clear all rx error injections
37 # tx-clear clear all tx error injections
39 # <op> rx-clear clear all rx error injections for <op>
40 # <op> tx-clear clear all tx error injections for <op>
43 # <op>[,<mode>] rx-nack NACK the message instead of sending an ACK
44 # <op>[,<mode>] rx-low-drive <bit> force a low-drive condition at this bit position
45 # <op>[,<mode>] rx-add-byte add a spurious byte to the received CEC message
46 # <op>[,<mode>] rx-remove-byte remove the last byte from the received CEC message
47 # any[,<mode>] rx-arb-lost [<poll>] generate a POLL message to trigger an arbitration lost
50 # tx-ignore-nack-until-eom ignore early NACKs until EOM
51 # tx-custom-low-usecs <usecs> define the 'low' time for the custom pulse
52 # tx-custom-high-usecs <usecs> define the 'high' time for the custom pulse
53 # tx-custom-pulse transmit the custom pulse once the bus is idle
56 # <op>[,<mode>] tx-no-eom don't set the EOM bit
57 # <op>[,<mode>] tx-early-eom set the EOM bit one byte too soon
58 # <op>[,<mode>] tx-add-bytes <num> append <num> (1-255) spurious bytes to the message
59 # <op>[,<mode>] tx-remove-byte drop the last byte from the message
60 # <op>[,<mode>] tx-short-bit <bit> make this bit shorter than allowed
61 # <op>[,<mode>] tx-long-bit <bit> make this bit longer than allowed
62 # <op>[,<mode>] tx-custom-bit <bit> send the custom pulse instead of this bit
63 # <op>[,<mode>] tx-short-start send a start pulse that's too short
64 # <op>[,<mode>] tx-long-start send a start pulse that's too long
65 # <op>[,<mode>] tx-custom-start send the custom pulse instead of the start pulse
66 # <op>[,<mode>] tx-last-bit <bit> stop sending after this bit
67 # <op>[,<mode>] tx-low-drive <bit> force a low-drive condition at this bit position
69 # <op> CEC message opcode (0-255) or 'any'
71 # <bit> CEC message bit (0-159)
72 # 10 bits per 'byte': bits 0-7: data, bit 8: EOM, bit 9: ACK
73 # <poll> CEC poll message used to test arbitration lost (0x00-0xff, default 0x0f)
74 # <usecs> microseconds (0-10000000, default 1000)
78 You can write error injection commands to ``error-inj`` using
79 ``echo 'cmd' >error-inj`` or ``cat cmd.txt >error-inj``. The ``cat error-inj``
81 and use it as an input to ``error-inj`` later.
84 ------------
93 to create custom pulses on the CEC bus.
103 So '``any rx-nack``' will NACK the next received CEC message,
104 '``any,always rx-nack``' will NACK all received CEC messages and
105 '``0x82,toggle rx-nack``' will only NACK if an Active Source message was
109 is cleared automatically, so ``once`` is a one-time deal.
111 All combinations of ``<op>`` and error injection commands can co-exist. So
114 0x9e tx-add-bytes 1
115 0x9e tx-early-eom
116 0x9f tx-add-bytes 2
117 any rx-nack
124 0x9e tx-add-bytes 1
125 0x9e tx-add-bytes 2
130 ----------------------
135 ``rx-clear``
138 ``tx-clear``
144 ``<op> rx-clear``
147 ``<op> tx-clear``
151 ----------------
153 ``<op>[,<mode>] rx-nack``
158 ``<op>[,<mode>] rx-low-drive <bit>``
167 ``<op>[,<mode>] rx-add-byte``
170 the high-level protocol since spurious bytes should be ignored.
172 ``<op>[,<mode>] rx-remove-byte``
174 was at least 2 bytes long. This is useful to test the high-level
177 ``<op>[,<mode>] rx-arb-lost <poll>``
195 -----------------
197 ``tx-ignore-nack-until-eom``
200 specification also allows that the full message is transmitted and only
208 ``<op>[,<mode>] tx-no-eom``
210 (End-Of-Message) bit set. With this command the transmit will just stop
212 handles this case. Normally receivers have a time-out after which
215 ``<op>[,<mode>] tx-early-eom``
217 of two bytes or more. The EOM bit will be set for the second-to-last byte
223 ``<op>[,<mode>] tx-add-bytes <num>``
224 Append ``<num>`` (1-255) spurious bytes to the message. The extra bytes
227 the full message received by the remote CEC adapter is
234 ``<op>[,<mode>] tx-remove-byte``
238 ``<op>[,<mode>] tx-short-bit <bit>``
251 sees a too-short 0 bit.
253 ``<op>[,<mode>] tx-long-bit <bit>``
269 sees a too-long 0 bit.
271 ``<op>[,<mode>] tx-short-start``
278 ``<op>[,<mode>] tx-long-start``
290 ``<op>[,<mode>] tx-last-bit <bit>``
297 ``<op>[,<mode>] tx-low-drive <bit>``
302 positions 0-3 the receiver can interpret this as an Arbitration Lost
305 Custom Pulses
306 -------------
308 ``tx-custom-low-usecs <usecs>``
309 This defines the duration in microseconds that the custom pulse pulls
312 ``tx-custom-high-usecs <usecs>``
313 This defines the duration in microseconds that the custom pulse keeps the
315 The default is 1000 microseconds. The total period of the custom pulse is
316 ``tx-custom-low-usecs + tx-custom-high-usecs``.
318 ``<op>[,<mode>] tx-custom-bit <bit>``
319 Send the custom bit instead of a regular data bit. The bit position cannot
323 ``<op>[,<mode>] tx-custom-start``
324 Send the custom bit instead of a regular start bit.
326 ``tx-custom-pulse``
327 Transmit a single custom pulse as soon as the CEC bus is idle.