xref: /linux/Documentation/ABI/testing/sysfs-tty (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
1fbc92a34SKay SieversWhat:		/sys/class/tty/console/active
2fbc92a34SKay SieversDate:		Nov 2010
3fbc92a34SKay SieversContact:	Kay Sievers <kay.sievers@vrfy.org>
4fbc92a34SKay SieversDescription:
5fbc92a34SKay Sievers		 Shows the list of currently configured
65c0a2450SGreg Kroah-Hartman		 console devices, like 'tty1 ttyS0'.
7fbc92a34SKay Sievers		 The last entry in the file is the active
8fbc92a34SKay Sievers		 device connected to /dev/console.
9fbc92a34SKay Sievers		 The file supports poll() to detect virtual
10fbc92a34SKay Sievers		 console switches.
11fbc92a34SKay Sievers
1205d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/tty<x>/active
13fbc92a34SKay SieversDate:		Nov 2010
14fbc92a34SKay SieversContact:	Kay Sievers <kay.sievers@vrfy.org>
15fbc92a34SKay SieversDescription:
16fbc92a34SKay Sievers		 Shows the currently active virtual console
17fbc92a34SKay Sievers		 device, like 'tty1'.
18fbc92a34SKay Sievers		 The file supports poll() to detect virtual
19fbc92a34SKay Sievers		 console switches.
206915c0e4STomas Hlavacek
2105d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/uartclk
226915c0e4STomas HlavacekDate:		Sep 2012
236915c0e4STomas HlavacekContact:	Tomas Hlavacek <tmshlvck@gmail.com>
246915c0e4STomas HlavacekDescription:
256915c0e4STomas Hlavacek		 Shows the current uartclk value associated with the
266915c0e4STomas Hlavacek		 UART port in serial_core, that is bound to TTY like ttyS0.
276915c0e4STomas Hlavacek		 uartclk = 16 * baud_base
286915c0e4STomas Hlavacek
29373bac4cSAlan Cox		 These sysfs values expose the TIOCGSERIAL interface via
30373bac4cSAlan Cox		 sysfs rather than via ioctls.
31373bac4cSAlan Cox
3205d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/type
33373bac4cSAlan CoxDate:		October 2012
34373bac4cSAlan CoxContact:	Alan Cox <alan@linux.intel.com>
35373bac4cSAlan CoxDescription:
36373bac4cSAlan Cox		 Shows the current tty type for this port.
37373bac4cSAlan Cox
38373bac4cSAlan Cox		 These sysfs values expose the TIOCGSERIAL interface via
39373bac4cSAlan Cox		 sysfs rather than via ioctls.
40373bac4cSAlan Cox
4105d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/line
42373bac4cSAlan CoxDate:		October 2012
43373bac4cSAlan CoxContact:	Alan Cox <alan@linux.intel.com>
44373bac4cSAlan CoxDescription:
45373bac4cSAlan Cox		 Shows the current tty line number for this port.
46373bac4cSAlan Cox
47373bac4cSAlan Cox		 These sysfs values expose the TIOCGSERIAL interface via
48373bac4cSAlan Cox		 sysfs rather than via ioctls.
49373bac4cSAlan Cox
5005d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/port
51373bac4cSAlan CoxDate:		October 2012
52373bac4cSAlan CoxContact:	Alan Cox <alan@linux.intel.com>
53373bac4cSAlan CoxDescription:
54373bac4cSAlan Cox		 Shows the current tty port I/O address for this port.
55373bac4cSAlan Cox
56373bac4cSAlan Cox		 These sysfs values expose the TIOCGSERIAL interface via
57373bac4cSAlan Cox		 sysfs rather than via ioctls.
58373bac4cSAlan Cox
5905d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/irq
60373bac4cSAlan CoxDate:		October 2012
61373bac4cSAlan CoxContact:	Alan Cox <alan@linux.intel.com>
62373bac4cSAlan CoxDescription:
63373bac4cSAlan Cox		 Shows the current primary interrupt for this port.
64373bac4cSAlan Cox
65373bac4cSAlan Cox		 These sysfs values expose the TIOCGSERIAL interface via
66373bac4cSAlan Cox		 sysfs rather than via ioctls.
67373bac4cSAlan Cox
6805d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/flags
69373bac4cSAlan CoxDate:		October 2012
70373bac4cSAlan CoxContact:	Alan Cox <alan@linux.intel.com>
71373bac4cSAlan CoxDescription:
72373bac4cSAlan Cox		 Show the tty port status flags for this port.
73373bac4cSAlan Cox
74373bac4cSAlan Cox		 These sysfs values expose the TIOCGSERIAL interface via
75373bac4cSAlan Cox		 sysfs rather than via ioctls.
76373bac4cSAlan Cox
7705d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/xmit_fifo_size
78373bac4cSAlan CoxDate:		October 2012
79373bac4cSAlan CoxContact:	Alan Cox <alan@linux.intel.com>
80373bac4cSAlan CoxDescription:
81373bac4cSAlan Cox		 Show the transmit FIFO size for this port.
82373bac4cSAlan Cox
83373bac4cSAlan Cox		 These sysfs values expose the TIOCGSERIAL interface via
84373bac4cSAlan Cox		 sysfs rather than via ioctls.
85373bac4cSAlan Cox
8605d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/close_delay
87373bac4cSAlan CoxDate:		October 2012
88373bac4cSAlan CoxContact:	Alan Cox <alan@linux.intel.com>
89373bac4cSAlan CoxDescription:
90*d8a5c0d6SSimon Arlott		Show the closing delay time for this port in centiseconds.
91373bac4cSAlan Cox
92373bac4cSAlan Cox		These sysfs values expose the TIOCGSERIAL interface via
93373bac4cSAlan Cox		sysfs rather than via ioctls.
94373bac4cSAlan Cox
9505d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/closing_wait
96373bac4cSAlan CoxDate:		October 2012
97373bac4cSAlan CoxContact:	Alan Cox <alan@linux.intel.com>
98373bac4cSAlan CoxDescription:
99*d8a5c0d6SSimon Arlott		Show the close wait time for this port in centiseconds.
100*d8a5c0d6SSimon Arlott
101*d8a5c0d6SSimon Arlott		Waiting forever is represented as 0. If waiting on close is
102*d8a5c0d6SSimon Arlott		disabled then the value is 65535.
103373bac4cSAlan Cox
104373bac4cSAlan Cox		These sysfs values expose the TIOCGSERIAL interface via
105373bac4cSAlan Cox		sysfs rather than via ioctls.
106373bac4cSAlan Cox
10705d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/custom_divisor
108373bac4cSAlan CoxDate:		October 2012
109373bac4cSAlan CoxContact:	Alan Cox <alan@linux.intel.com>
110373bac4cSAlan CoxDescription:
111373bac4cSAlan Cox		 Show the custom divisor if any that is set on this port.
112373bac4cSAlan Cox
113373bac4cSAlan Cox		 These sysfs values expose the TIOCGSERIAL interface via
114373bac4cSAlan Cox		 sysfs rather than via ioctls.
115373bac4cSAlan Cox
11605d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/io_type
117373bac4cSAlan CoxDate:		October 2012
118373bac4cSAlan CoxContact:	Alan Cox <alan@linux.intel.com>
119373bac4cSAlan CoxDescription:
120373bac4cSAlan Cox		 Show the I/O type that is to be used with the iomem base
121373bac4cSAlan Cox		 address.
122373bac4cSAlan Cox
123373bac4cSAlan Cox		 These sysfs values expose the TIOCGSERIAL interface via
124373bac4cSAlan Cox		 sysfs rather than via ioctls.
125373bac4cSAlan Cox
12605d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/iomem_base
127373bac4cSAlan CoxDate:		October 2012
128373bac4cSAlan CoxContact:	Alan Cox <alan@linux.intel.com>
129373bac4cSAlan CoxDescription:
130373bac4cSAlan Cox		 The I/O memory base for this port.
131373bac4cSAlan Cox
132373bac4cSAlan Cox		 These sysfs values expose the TIOCGSERIAL interface via
133373bac4cSAlan Cox		 sysfs rather than via ioctls.
134373bac4cSAlan Cox
13505d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/iomem_reg_shift
136373bac4cSAlan CoxDate:		October 2012
137373bac4cSAlan CoxContact:	Alan Cox <alan@linux.intel.com>
138373bac4cSAlan CoxDescription:
139373bac4cSAlan Cox		 Show the register shift indicating the spacing to be used
140373bac4cSAlan Cox		 for accesses on this iomem address.
141373bac4cSAlan Cox
142373bac4cSAlan Cox		 These sysfs values expose the TIOCGSERIAL interface via
143373bac4cSAlan Cox		 sysfs rather than via ioctls.
144aef9a7bdSYoshihiro YUNOMAE
14505d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/rx_trig_bytes
146aef9a7bdSYoshihiro YUNOMAEDate:		May 2014
147aef9a7bdSYoshihiro YUNOMAEContact:	Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
148aef9a7bdSYoshihiro YUNOMAEDescription:
149aef9a7bdSYoshihiro YUNOMAE		 Shows current RX interrupt trigger bytes or sets the
150aef9a7bdSYoshihiro YUNOMAE		 user specified value to change it for the FIFO buffer.
151aef9a7bdSYoshihiro YUNOMAE		 Users can show or set this value regardless of opening the
152aef9a7bdSYoshihiro YUNOMAE		 serial device file or not.
153aef9a7bdSYoshihiro YUNOMAE
154aef9a7bdSYoshihiro YUNOMAE		 The RX trigger can be set one of four kinds of values for UART
155aef9a7bdSYoshihiro YUNOMAE		 serials. When users input a meaning less value to this I/F,
156aef9a7bdSYoshihiro YUNOMAE		 the RX trigger is changed to the nearest lower value for the
157aef9a7bdSYoshihiro YUNOMAE		 device specification. For example, when user sets 7bytes on
158aef9a7bdSYoshihiro YUNOMAE		 16550A, which has 1/4/8/14 bytes trigger, the RX trigger is
159aef9a7bdSYoshihiro YUNOMAE		 automatically changed to 4 bytes.
160a3cb39d2SAndy Shevchenko
16105d2024aSMauro Carvalho ChehabWhat:		/sys/class/tty/ttyS<x>/console
162a3cb39d2SAndy ShevchenkoDate:		February 2020
163a3cb39d2SAndy ShevchenkoContact:	Andy Shevchenko <andriy.shevchenko@linux.intel.com>
164a3cb39d2SAndy ShevchenkoDescription:
165a3cb39d2SAndy Shevchenko		 Allows user to detach or attach back the given device as
166a3cb39d2SAndy Shevchenko		 kernel console. It shows and accepts a boolean variable.
167