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path: root/drivers/tty/Makefile
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2015-03-31TTY: Add MIPS EJTAG Fast Debug Channel TTY driverJames Hogan
Add TTY driver and consoles for the MIPS EJTAG Fast Debug Channel (FDC), which is found on the per-CPU MIPS Common Device Mapped Memory (CDMM) bus. The FDC is a per-CPU device which is used to communicate with an EJTAG probe. RX and TX FIFOs exist, containing 32-bits of data and 4-bit channel numbers. 16 general data streams are implemented on this for TTY and console use by encoding up to 4 bytes on each 32-bit FDC word. The TTY devices are named e.g. /dev/ttyFDC3c2 for channel 2 of the FDC attached to logical CPU 3. These can be used for getting the kernel log, a login prompt, or as a GDB remote transport, all over EJTAG and without needing a serial port. It can have an interrupt to notify of when incoming data is available in the RX FIFO or when the TX FIFO is no longer full. The detection of this interrupt occurs in architecture / platform code, but it may be shared with the timer and/or performance counter interrupt. Due to the per-CPU nature of the hardware, all outgoing TTY data is written out from a kthread which is pinned to the appropriate CPU. The console is not bound to a specific CPU, so output will appear on the chosen channel on whichever CPU the code is executing on. Enable with e.g. console=fdc1 in kernel arguments. /dev/console is bound to the same channel on the boot CPU's FDC if it exists. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9146/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-20tty: Add timed, writer-prioritized rw semaphorePeter Hurley
The semantics of a rw semaphore are almost ideally suited for tty line discipline lifetime management; multiple active threads obtain "references" (read locks) while performing i/o to prevent the loss or change of the current line discipline (write lock). Unfortunately, the existing rw_semaphore is ill-suited in other ways; 1) TIOCSETD ioctl (change line discipline) expects to return an error if the line discipline cannot be exclusively locked within 5 secs. Lock wait timeouts are not supported by rwsem. 2) A tty hangup is expected to halt and scrap pending i/o, so exclusive locking must be prioritized. Writer priority is not supported by rwsem. Add ld_semaphore which implements these requirements in a semantically similar way to rw_semaphore. Writer priority is handled by separate wait lists for readers and writers. Pending write waits are priortized before existing read waits and prevent further read locks. Wait timeouts are trivially added, but obviously change the lock semantics as lock attempts can fail (but only due to timeout). This implementation incorporates the write-lock stealing work of Michel Lespinasse <walken@google.com>. Cc: Michel Lespinasse <walken@google.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-06tty: metag_da: Add metag DA TTY driverJames Hogan
Add a TTY driver for communicating over a Meta DA (Debug Adapter) channel using the bios channel SWITCH operation. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-21goldfish: tty driverArve Hjønnevåg
This provides a console driver for the Goldfish virtual platform. The original is from Arve with changes from Jun Nakajima and Tom Keel. This has been then been ported to the current kernel and to the tty port mechanism by Alan Cox. In the process it gained proper POSIX semantics and vhangup works. The default name is not ttyS as this belongs to the 8250 driver. Instead ttyGFx is now used. In the normal usage case the first port serves as a kernel logging console and the second one carries various other data streams for the emulation. Signed-off-by: Arve Hjønnevåg <arve@google.com> [Cleaned up to handle x86] Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com> Signed-off-by: Xiaohui Xin <xiaohui.xin@intel.com> Signed-off-by: Jun Nakajima <jun.nakajima@intel.com> Signed-off-by: Bruce Beare <bruce.j.beare@intel.com> [Moved to 3.7 and chunks rewritten to use tty_port layer] Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-18tty: Added a CONFIG_TTY option to allow removal of TTYJoe Millenbach
The option allows you to remove TTY and compile without errors. This saves space on systems that won't support TTY interfaces anyway. bloat-o-meter output is below. The bulk of this patch consists of Kconfig changes adding "depends on TTY" to various serial devices and similar drivers that require the TTY layer. Ideally, these dependencies would occur on a common intermediate symbol such as SERIO, but most drivers "select SERIO" rather than "depends on SERIO", and "select" does not respect dependencies. bloat-o-meter output comparing our previous minimal to new minimal by removing TTY. The list is filtered to not show removed entries with awk '$3 != "-"' as the list was very long. add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350) function old new delta chr_dev_init 166 170 +4 allow_signal 80 82 +2 static.__warned 143 142 -1 disallow_signal 63 62 -1 __set_special_pids 95 94 -1 unregister_console 126 121 -5 start_kernel 546 541 -5 register_console 593 588 -5 copy_from_user 45 40 -5 sys_setsid 128 120 -8 sys_vhangup 32 19 -13 do_exit 1543 1526 -17 bitmap_zero 60 40 -20 arch_local_irq_save 137 117 -20 release_task 674 652 -22 static.spin_unlock_irqrestore 308 260 -48 Signed-off-by: Joe Millenbach <jmillenbach@gmail.com> Reviewed-by: Jamey Sharp <jamey@minilop.net> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-08-23tty/powerpc: introduce the ePAPR embedded hypervisor byte channel driverTimur Tabi
The ePAPR embedded hypervisor specification provides an API for "byte channels", which are serial-like virtual devices for sending and receiving streams of bytes. This driver provides Linux kernel support for byte channels via three distinct interfaces: 1) An early-console (udbg) driver. This provides early console output through a byte channel. The byte channel handle must be specified in a Kconfig option. 2) A normal console driver. Output is sent to the byte channel designated for stdout in the device tree. The console driver is for handling kernel printk calls. 3) A tty driver, which is used to handle user-space input and output. The byte channel used for the console is designated as the default tty. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-13n_tracerouter and n_tracesink ldisc additions.J Freyensee
The n_tracerouter and n_tracesink line discpline drivers use the Linux tty line discpline framework to route trace data coming from a tty port (say UART for example) to the trace sink line discipline driver and to another tty port(say USB). Those these two line discipline drivers can be used together, independently from pti.c, they are part of the original implementation solution of the MIPI P1149.7, compact JTAG, PTI solution for Intel mobile platforms starting with the Medfield platform. Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-22tty: move ipwireless driver from drivers/char/pcmcia/ to drivers/tty/Greg Kroah-Hartman
As planned by Arnd Bergmann, this moves the ipwireless driver to the drivers/tty/ directory as that's where it really belongs. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Jiri Slaby <jslaby@suse.cz> Cc: David Sterba <dsterba@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-22tty: move a number of tty drivers from drivers/char/ to drivers/tty/Greg Kroah-Hartman
As planned by Arnd Bergmann, this moves the following drivers from drivers/char/ to drivers/tty/ as that's where they really belong: amiserial nozomi synclink rocket cyclades moxa mxser isicom bfin_jtag_comm Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-13tty: move drivers/serial/ to drivers/tty/serial/Greg Kroah-Hartman
The serial drivers are really just tty drivers, so move them to drivers/tty/ to make things a bit neater overall. This is part of the tty/serial driver movement proceedure as proposed by Arnd Bergmann and approved by everyone involved a number of months ago. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl> Cc: Michael H. Warfield <mhw@wittsend.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-13tty: move hvc drivers to drivers/tty/hvc/Greg Kroah-Hartman
As requested by Arnd Bergmann, the hvc drivers are now moved to the drivers/tty/hvc/ directory. The virtio_console.c driver was also moved, as it required the hvc_console.h file to be able to be built, and it really is a hvc driver. Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-05TTY: create drivers/tty/vt and move the vt code thereGreg Kroah-Hartman
The vt and other related code is moved into the drivers/tty/vt directory. Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-05TTY: create drivers/tty and move the tty core files thereGreg Kroah-Hartman
The tty code should be in its own subdirectory and not in the char driver with all of the cruft that is currently there. Based on work done by Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>