€•6Œsphinx.addnodes”Œdocument”“”)”}”(Œ rawsource”Œ”Œchildren”]”(Œ translations”Œ LanguagesNode”“”)”}”(hhh]”(hŒ pending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ refdomain”Œstd”Œreftype”Œdoc”Œ reftarget”Œ(/translations/zh_CN/driver-api/tty/index”Œmodname”NŒ classname”NŒ refexplicit”ˆuŒtagname”hhh ubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ(/translations/zh_TW/driver-api/tty/index”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ(/translations/it_IT/driver-api/tty/index”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ(/translations/ja_JP/driver-api/tty/index”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ(/translations/ko_KR/driver-api/tty/index”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒPortuguese (Brazilian)”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ(/translations/pt_BR/driver-api/tty/index”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒSpanish”…””}”hh–sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ(/translations/sp_SP/driver-api/tty/index”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h hhŒ _document”hŒsource”NŒline”NubhŒcomment”“”)”}”(hŒ SPDX-License-Identifier: GPL-2.0”h]”hŒ SPDX-License-Identifier: GPL-2.0”…””}”hh·sbah}”(h]”h ]”h"]”h$]”h&]”Œ xml:space”Œpreserve”uh1hµhhh²hh³ŒB/var/lib/git/docbuild/linux/Documentation/driver-api/tty/index.rst”h´KubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒTTY”h]”hŒTTY”…””}”(hhÏh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhhÊh²hh³hÇh´KubhŒ paragraph”“”)”}”(hŒxTeletypewriter (TTY) layer takes care of all those serial devices. Including the virtual ones like pseudoterminal (PTY).”h]”hŒxTeletypewriter (TTY) layer takes care of all those serial devices. Including the virtual ones like pseudoterminal (PTY).”…””}”(hhßh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KhhÊh²hubhÉ)”}”(hhh]”(hÎ)”}”(hŒTTY structures”h]”hŒTTY structures”…””}”(hhðh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhhíh²hh³hÇh´K ubhÞ)”}”(hXõThere are several major TTY structures. Every TTY device in a system has a corresponding struct tty_port. These devices are maintained by a TTY driver which is struct tty_driver. This structure describes the driver but also contains a reference to operations which could be performed on the TTYs. It is struct tty_operations. Then, upon open, a struct tty_struct is allocated and lives until the final close. During this time, several callbacks from struct tty_operations are invoked by the TTY layer.”h]”hXõThere are several major TTY structures. Every TTY device in a system has a corresponding struct tty_port. These devices are maintained by a TTY driver which is struct tty_driver. This structure describes the driver but also contains a reference to operations which could be performed on the TTYs. It is struct tty_operations. Then, upon open, a struct tty_struct is allocated and lives until the final close. During this time, several callbacks from struct tty_operations are invoked by the TTY layer.”…””}”(hhþh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K hhíh²hubhÞ)”}”(hXÆEvery character received by the kernel (both from devices and users) is passed through a preselected :doc:`tty_ldisc` (in short ldisc; in C, struct tty_ldisc_ops). Its task is to transform characters as defined by a particular ldisc or by user too. The default one is n_tty, implementing echoes, signal handling, jobs control, special characters processing, and more. The transformed characters are passed further to user/device, depending on the source.”h]”(hŒeEvery character received by the kernel (both from devices and users) is passed through a preselected ”…””}”(hj h²hh³Nh´Nubh)”}”(hŒ:doc:`tty_ldisc`”h]”hŒinline”“”)”}”(hjh]”hŒ tty_ldisc”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”(Œxref”Œstd”Œstd-doc”eh"]”h$]”h&]”uh1jhjubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”Œdriver-api/tty/index”Œ refdomain”j%Œreftype”Œdoc”Œ refexplicit”‰Œrefwarn”ˆŒ reftarget”Œ tty_ldisc”uh1hh³hÇh´Khj ubhXQ (in short ldisc; in C, struct tty_ldisc_ops). Its task is to transform characters as defined by a particular ldisc or by user too. The default one is n_tty, implementing echoes, signal handling, jobs control, special characters processing, and more. The transformed characters are passed further to user/device, depending on the source.”…””}”(hj h²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´Khhíh²hubhÞ)”}”(hŒKIn-detail description of the named TTY structures is in separate documents:”h]”hŒKIn-detail description of the named TTY structures is in separate documents:”…””}”(hjCh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´Khhíh²hubhŒcompound”“”)”}”(hhh]”hŒtoctree”“”)”}”(hhh]”h}”(h]”h ]”h"]”h$]”h&]”hj1Œentries”]”(NŒdriver-api/tty/tty_driver”†”NŒdriver-api/tty/tty_port”†”NŒdriver-api/tty/tty_struct”†”NŒdriver-api/tty/tty_ldisc”†”NŒdriver-api/tty/tty_buffer”†”NŒdriver-api/tty/tty_ioctl”†”NŒdriver-api/tty/tty_internals”†”NŒdriver-api/tty/console”†”eŒ includefiles”]”(jcjejgjijkjmjojqeŒmaxdepth”KŒcaption”NŒglob”‰Œhidden”‰Œ includehidden”‰Œnumbered”KŒ titlesonly”‰Œ rawentries”]”uh1jVh³hÇh´KhjSubah}”(h]”h ]”Œtoctree-wrapper”ah"]”h$]”h&]”uh1jQhhíh²hh³hÇh´Nubeh}”(h]”Œtty-structures”ah ]”h"]”Œtty structures”ah$]”h&]”uh1hÈhhÊh²hh³hÇh´K ubhÉ)”}”(hhh]”(hÎ)”}”(hŒWriting TTY Driver”h]”hŒWriting TTY Driver”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhjh²hh³hÇh´K,ubhÞ)”}”(hXnBefore one starts writing a TTY driver, they must consider :doc:`Serial <../serial/driver>` and :doc:`USB Serial <../../usb/usb-serial>` layers first. Drivers for serial devices can often use one of these specific layers to implement a serial driver. Only special devices should be handled directly by the TTY Layer. If you are about to write such a driver, read on.”h]”(hŒ;Before one starts writing a TTY driver, they must consider ”…””}”(hjžh²hh³Nh´Nubh)”}”(hŒ :doc:`Serial <../serial/driver>`”h]”j)”}”(hj¨h]”hŒSerial”…””}”(hjªh²hh³Nh´Nubah}”(h]”h ]”(j$Œstd”Œstd-doc”eh"]”h$]”h&]”uh1jhj¦ubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j1Œ refdomain”j´Œreftype”Œdoc”Œ refexplicit”ˆŒrefwarn”ˆj7Œ../serial/driver”uh1hh³hÇh´K.hjžubhŒ and ”…””}”(hjžh²hh³Nh´Nubh)”}”(hŒ(:doc:`USB Serial <../../usb/usb-serial>`”h]”j)”}”(hjÌh]”hŒ USB Serial”…””}”(hjÎh²hh³Nh´Nubah}”(h]”h ]”(j$Œstd”Œstd-doc”eh"]”h$]”h&]”uh1jhjÊubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j1Œ refdomain”jØŒreftype”Œdoc”Œ refexplicit”ˆŒrefwarn”ˆj7Œ../../usb/usb-serial”uh1hh³hÇh´K.hjžubhŒæ layers first. Drivers for serial devices can often use one of these specific layers to implement a serial driver. Only special devices should be handled directly by the TTY Layer. If you are about to write such a driver, read on.”…””}”(hjžh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K.hjh²hubhÞ)”}”(hŒ9A *typical* sequence a TTY driver performs is as follows:”h]”(hŒA ”…””}”(hjôh²hh³Nh´NubhŒemphasis”“”)”}”(hŒ *typical*”h]”hŒtypical”…””}”(hjþh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jühjôubhŒ. sequence a TTY driver performs is as follows:”…””}”(hjôh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K4hjh²hubhŒenumerated_list”“”)”}”(hhh]”(hŒ list_item”“”)”}”(hŒ0Allocate and register a TTY driver (module init)”h]”hÞ)”}”(hjh]”hŒ0Allocate and register a TTY driver (module init)”…””}”(hj!h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K6hjubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjh²hh³hÇh´Nubj)”}”(hŒCCreate and register TTY devices as they are probed (probe function)”h]”hÞ)”}”(hj6h]”hŒCCreate and register TTY devices as they are probed (probe function)”…””}”(hj8h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K7hj4ubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjh²hh³hÇh´Nubj)”}”(hŒeHandle TTY operations and events like interrupts (TTY core invokes the former, the device the latter)”h]”hÞ)”}”(hŒeHandle TTY operations and events like interrupts (TTY core invokes the former, the device the latter)”h]”hŒeHandle TTY operations and events like interrupts (TTY core invokes the former, the device the latter)”…””}”(hjOh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K8hjKubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjh²hh³hÇh´Nubj)”}”(hŒ7Remove devices as they are going away (remove function)”h]”hÞ)”}”(hjeh]”hŒ7Remove devices as they are going away (remove function)”…””}”(hjgh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K:hjcubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjh²hh³hÇh´Nubj)”}”(hŒ1Unregister and free the TTY driver (module exit) ”h]”hÞ)”}”(hŒ0Unregister and free the TTY driver (module exit)”h]”hŒ0Unregister and free the TTY driver (module exit)”…””}”(hj~h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K;hjzubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjh²hh³hÇh´Nubeh}”(h]”h ]”h"]”h$]”h&]”Œenumtype”Œarabic”Œprefix”hŒsuffix”Œ.”uh1jhjh²hh³hÇh´K6ubhÞ)”}”(hŒšSteps regarding driver, i.e. 1., 3., and 5. are described in detail in :doc:`tty_driver`. For the other two (devices handling), look into :doc:`tty_port`.”h]”(hŒGSteps regarding driver, i.e. 1., 3., and 5. are described in detail in ”…””}”(hjh²hh³Nh´Nubh)”}”(hŒ:doc:`tty_driver`”h]”j)”}”(hj§h]”hŒ tty_driver”…””}”(hj©h²hh³Nh´Nubah}”(h]”h ]”(j$Œstd”Œstd-doc”eh"]”h$]”h&]”uh1jhj¥ubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j1Œ refdomain”j³Œreftype”Œdoc”Œ refexplicit”‰Œrefwarn”ˆj7Œ tty_driver”uh1hh³hÇh´K=hjubhŒ2. 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