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* serial: Fix locking for uart driver set_termios() methodPeter Hurley2014-11-051-2/+4
| | | | | | | | | | | | | | | | | | | | | | The low-level uart driver may modify termios settings to override settings that are not compatible with the uart, such as CRTSCTS. Thus, callers of the low-level uart driver's set_termios() method must hold termios_rwsem write lock to prevent concurrent access to termios, in case such override occurs. The termios_rwsem lock requirement does not extend to console setup (ie., uart_set_options), as console setup cannot race with tty operations. Nor does this lock requirement extend to functions which cannot be concurrent with tty ioctls (ie., uart_port_startup() and uart_resume_port()). Further, always claim the port mutex to protect hardware re-reprogramming in the set_termios() uart driver method. Note this is unnecessary for console initialization in uart_set_options() which cannot be concurrent with other uart operations. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Fix send_xchar() handlersPeter Hurley2014-09-081-0/+2
| | | | | | | | | | | | | | | | | START_CHAR() & STOP_CHAR() can be disabled if set to '\0' (__DISABLED_CHAR). UART drivers which define a send_xchar() handler must not transmit __DISABLED_CHAR. Document requirement. Affected drivers: sunsab sunhv cc: David S. Miller <davem@davemloft.net> cc: <sparclinux@vger.kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty/serial: Add GPIOLIB helpers for controlling modem linesRichard Genoud2014-05-281-0/+25
| | | | | | | | | | | | This patch add some helpers to control modem lines (CTS/RTS/DSR...) via GPIO. This will be useful for many boards which have a serial controller that only handle CTS/RTS pins (or even just RX/TX). Signed-off-by: Richard Genoud <richard.genoud@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Yegor Yefremov <yegorslists@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: delete .set_wake() callbackLinus Walleij2013-10-161-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This deletes the .set_wake() callback in the struct uart_ops. Apparently this has been unused since pre-git times. In the old-2.6-bkcvs it is deleted as part of a changeset removing the PM_SET_WAKEUP from pm_request_t which is since also deleted from the kernel. The apropriate way to set wakeups in the kernel is to have a code snippet like this in .suspend() or .runtime_suspend() callbacks: static int foo_suspend(struct device *dev) { if (device_may_wakeup(dev)) { /* Enable wakeups, set internal states */ } } This specific callback is not coming back. Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Kevin Hilman <khilman@deeprootsystems.com> Cc: Dmitry Artamonow <mad_soft@inbox.ru> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Update serial core API documentationKevin Cernekee2013-01-151-0/+39
| | | | | | Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial core: decouple pm states from ACPILinus Walleij2013-01-151-3/+2
| | | | | | | | | | | | The serial core is using power states lifted from ACPI for no good reason. Remove this reference from the documentation and alter all users to use an enum specific to the serial core instead, and define it in <linux/serial_core.h>. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Alan Cox <alan@linux.intel.com> Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial/documentation: fix documented name of DCD cpp symbolUwe Kleine-König2012-01-041-1/+1
| | | | | | | Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Alan Cox <alan@linux.intel.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Subject: [PATCH 1/2] serial: Add flush_buffer() operation to uart_opsHaavard Skinnemoen2008-07-201-0/+11
| | | | | | | | | | | | | | | | | Serial drivers using DMA (like the atmel_serial driver) tend to get very confused when the xmit buffer is flushed and nobody told them. They also tend to spew a lot of garbage since the DMA engine keeps running after the buffer is flushed and possibly refilled with unrelated data. This patch adds a new flush_buffer operation to the uart_ops struct, along with a call to it from uart_flush_buffer() right after the xmit buffer has been cleared. The driver can implement this in order to syncronize its internal DMA state with the xmit buffer when the buffer is flushed. Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [SERIAL] Update parity handling documentationPeter Korsgaard2006-06-021-4/+5
| | | | | | | | Update documentation to match reality. INPCK controls whether input parity checking is enabled. Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] Update serial driver documentationRussell King2006-04-151-4/+18
| | | | | | | | | | | | | Improve serial driver documentation: - Remove CVS id. - Update pointer to reference driver documentation. - Add comments about new uart_write_console function. - Add TIOCM_LOOP modem control bit description. - Add commentry about enable_ms method being called multiple times. - Add commentry about startup/shutdown method calling. - Mention that dereferencing port->info after shutdown is invalid. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] Update serial_core documentationRussell King2005-10-311-9/+57
| | | | Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] Clean up and fix tty transmission start/stopingRussell King2005-08-311-11/+4
| | | | | | | | | | | | | | | | | | | | | | | The start_tx and stop_tx methods were passed a flag to indicate whether the start/stop was from the tty start/stop callbacks, and some drivers used this flag to decide whether to ask the UART to immediately stop transmission (where the UART supports such a feature.) There are other cases when we wish this to occur - when CTS is lowered, or if we change from soft to hard flow control and CTS is inactive. In these cases, this flag was false, and we would allow the transmitter to drain before stopping. There is really only one case where we want to let the transmitter drain before disabling, and that's when we run out of characters to send. Hence, re-jig the start_tx and stop_tx methods to eliminate this flag, and introduce new functions for the special "disable and allow transmitter to drain" case. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [PATCH] Serial: Adjust serial lockingRussell King2005-06-291-2/+2
| | | | | | | | This patch changes the way serial ports are locked when getting modem status. This change is necessary because we will need to atomically read the modem status and take action depending on the CTS status. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+330
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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