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path: root/drivers/tty/serial/serial_core.c
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2023-06-01serial: core: Don't drop port_mutex in serial_core_remove_one_portSteven Price1-3/+1
Commit 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") required the caller to hold port_mutex rather than taking it locally. However the mutex_unlock() call wasn't removed causing the mutex to be dropped unexpectly. Remove the call to mutex_unlock() (and fix up the early return) to restore correct behaviour. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Signed-off-by: Steven Price <steven.price@arm.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20230601105548.29965-1-steven.price@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-31serial: core: Start managing serial controllers to enable runtime PMTony Lindgren1-21/+171
We want to enable runtime PM for serial port device drivers in a generic way. To do this, we want to have the serial core layer manage the registered physical serial controller devices. To manage serial controllers, let's set up a struct bus and struct device for the serial core controller as suggested by Greg and Jiri. The serial core controller devices are children of the physical serial port device. The serial core controller device is needed to support multiple different kind of ports connected to single physical serial port device. Let's also set up a struct device for the serial core port. The serial core port instances are children of the serial core controller device. With the serial core port device we can now flush pending TX on the runtime PM resume as suggested by Johan. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Jiri Slaby <jirislaby@kernel.org> Suggested-by: Johan Hovold <johan@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230525113034.46880-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30serial: core: lock port for start_rx() in uart_resume_port()John Ogness1-1/+4
The only user of the start_rx() callback (qcom_geni) directly calls its own stop_rx() callback. Since stop_rx() requires that the port->lock is taken and interrupts are disabled, the start_rx() callback has the same requirement. Fixes: cfab87c2c271 ("serial: core: Introduce callback for start_rx and do stop_rx in suspend only if this callback implementation is present.") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230525093159.223817-5-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30serial: core: lock port for stop_rx() in uart_suspend_port()John Ogness1-1/+4
The uarts_ops stop_rx() callback expects that the port->lock is taken and interrupts are disabled. Fixes: c9d2325cdb92 ("serial: core: Do stop_rx in suspend path for console if console_suspend is disabled") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230525093159.223817-3-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-13serial: Make uart_remove_one_port() return voidUwe Kleine-König1-5/+1
The return value is only ever used as a return value for remove callbacks of platform drivers. This return value is ignored by the driver core. (The only effect is an error message, but uart_remove_one_port() already emitted one in this case.) So the return value isn't used at all and uart_remove_one_port() can be changed to return void without any loss. Also this better matches the Linux device model as remove functions are not supposed to fail. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20230512173810.131447-3-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20serial: core: Disable uart_start() on uart_remove_one_port()Tony Lindgren1-1/+1
While rebinding a uart device in a loop I noticed we may see a tx related race on uart_remove_one_port(): uart_write from n_tty_write n_tty_write from file_tty_write.constprop.0 file_tty_write.constprop.0 from vfs_write vfs_write from ksys_write ksys_write from ret_fast_syscall Let's disallow tx on port->UPF_DEAD. This flag gets set before we start tearing down the port in uart_remove_one_port(). Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20230419115423.59957-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20serial: fix TIOCSRS485 lockingJohan Hovold1-2/+2
The RS485 multipoint addressing support for some reason added a new ADDRB termios cflag which is (only!) updated from one of the RS485 ioctls. Make sure to take the termios rw semaphore for the right ioctl (i.e. set, not get). Fixes: ae50bb275283 ("serial: take termios_rwsem for ->rs485_config() & pass termios as param") Cc: stable@vger.kernel.org # 6.0 Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20230412124811.11217-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-29serial: uart_poll_init() should power on the UARTDouglas Anderson1-0/+6
On Qualcomm devices which use the "geni" serial driver, kdb/kgdb won't be very happy if you use it but the resources of the port haven't been powered on. Today kdb/kgdb rely on someone else powering the port on. This could be the normal kernel console or an agetty running. Let's fix this to explicitly power things on when setting up a polling driver. Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230316132027.RESEND.1.I106c39498d8094c6f5e7ada42c7db17aa5c64e48@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17serial: Remove uart_wait_until_sent() forward declarationIlpo Järvinen1-1/+0
Remove unnecessary forward declaration of uart_wait_until_sent(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-9-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17serial: Rename hw_stopped to old_hw_stopped & improve logicIlpo Järvinen1-6/+5
hw_stopped in uart_change_line_settings() stores old hw_stopped, thus rename it appropriately. Alter logic to check first if the hw_stopped was changed, and then pick which function to call if it was because the logic is more obvious that way. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-8-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17serial: Make hw_stopped boolIlpo Järvinen1-3/+3
Convert hw_stopped in uart_port to bool because its more appropriate type for how it is used. Also convert the local variable in uart_change_line_settings() caching old hw_stopped to bool. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17serial: Rename uart_change_speed() to uart_change_line_settings()Ilpo Järvinen1-6/+6
uart_change_speed() changes more than just speed so rename it to more generic uart_change_line_settings(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17serial: Move uart_change_speed() earlierIlpo Järvinen1-48/+46
Move uart_change_speed() earlier to get rid of its forward declaration. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17serial: Use B0 instead of implicit zero assumptionIlpo Järvinen1-2/+2
Compare against B0 rather than assume B0 equals zero, which is true for all archs but explicit B0 makes the code more obvious. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17serial: Use ARRAY_SIZE() with iso7816 reserved arrayIlpo Järvinen1-1/+2
Instead of a literal, size the for loop iteration based on the actual array using ARRAY_SIZE(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-22Merge 6.2-rc5 into tty-nextGreg Kroah-Hartman1-0/+5
We need the serial/tty changes into this branch as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19tty: Call ->dtr_rts() parameter active consistentlyIlpo Järvinen1-4/+4
Convert various parameter names for ->dtr_rts() and related functions from onoff, on, and raise to active. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-12-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19serial: Make uart_handle_cts_change() status param bool activeIlpo Järvinen1-4/+4
Convert uart_handle_cts_change() to bool which is more appropriate than unsigned int. Rename status to active to better describe what the parameter means. While at it, make the comment about the active parameter easier to parse. Cleanup callsites from operations that are not necessary with bool. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-10-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19tty/serial: Make ->dcd_change()+uart_handle_dcd_change() status bool activeIlpo Järvinen1-4/+4
Convert status parameter for ->dcd_change() and uart_handle_dcd_change() to bool which matches to how the parameter is used. Rename status to active to better describe what the parameter means. Acked-by: Rodolfo Giometti <giometti@enneenne.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-9-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19tty: Convert ->dtr_rts() to take bool argumentIlpo Järvinen1-4/+4
Convert the raise/on parameter in ->dtr_rts() to bool through the callchain. The parameter is used like bool. In USB serial, there remains a few implicit bool -> larger type conversions because some devices use u8 in their control messages. In moxa_tiocmget(), dtr variable was reused for line status which requires int so use a separate variable for status. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-8-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19tty: Convert ->carrier_raised() and callchains to boolIlpo Järvinen1-5/+4
Return boolean from ->carrier_raised() instead of 0 and 1. Make the return type change also to tty_port_carrier_raised() that makes the ->carrier_raised() call (+ cd variable in moxa into which its return value is stored). Also cleans up a few unnecessary constructs related to this change: return xx ? 1 : 0; -> return xx; if (xx) return 1; return 0; -> return xx; Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19serial: Convert uart_{,port_}startup() init_hw param to boolIlpo Järvinen1-5/+5
Convert init_hw parameter in uart_startup() and uart_port_startup() to bool as code treats them like bool. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19tty: Cleanup tty_port_set_active() bool parameterIlpo Järvinen1-2/+2
Make callers pass true/false consistently for bool val. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19tty: Cleamup tty_port_set_suspended() bool parameterIlpo Järvinen1-4/+4
Make callers pass true/false consistently for bool val. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19tty: Cleanup tty_port_set_initialized() bool parameterIlpo Järvinen1-3/+3
Make callers pass true/false consistently for bool val. Reviewed-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19serial: core: Add option to output RS485 RX_DURING_TX state via GPIOChristoph Niedermaier1-0/+12
This patch provides a generic GPIO variable for outputting the state of RS485 RX_DURING_TX. The GPIO is defined by the devicetree property "rs485-rx-during-tx-gpios". To use it in a low level serial driver, the evaluation of this variable must be implemented there accordingly. Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com> Link: https://lore.kernel.org/r/20221202104127.122761-2-cniedermaier@dh-electronics.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-16tty: serial: kgdboc: fix mutex locking order for configure_kgdboc()John Ogness1-0/+5
Several mutexes are taken while setting up console serial ports. In particular, the tty_port->mutex and @console_mutex are taken: serial_pnp_probe serial8250_register_8250_port uart_add_one_port (locks tty_port->mutex) uart_configure_port register_console (locks @console_mutex) In order to synchronize kgdb's tty_find_polling_driver() with register_console(), commit 6193bc90849a ("tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console()") takes the @console_mutex. However, this leads to the following call chain (with locking): platform_probe kgdboc_probe configure_kgdboc (locks @console_mutex) tty_find_polling_driver uart_poll_init (locks tty_port->mutex) uart_set_options This is clearly deadlock potential due to the reverse lock ordering. Since uart_set_options() requires holding @console_mutex in order to serialize early initialization of the serial-console lock, take the @console_mutex in uart_poll_init() instead of configure_kgdboc(). Since configure_kgdboc() was using @console_mutex for safe traversal of the console list, change it to use the SRCU iterator instead. Add comments to uart_set_options() kerneldoc mentioning that it requires holding @console_mutex (aka the console_list_lock). Fixes: 6193bc90849a ("tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console()") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> [pmladek@suse.com: Export console_srcu_read_lock_is_held() to fix build kgdboc as a module.] Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230112161213.1434854-1-john.ogness@linutronix.de
2022-12-02serial_core: replace uart_console_enabled() with uart_console_registered()John Ogness1-7/+7
All users of uart_console_enabled() really want to know if a console is registered. It is not reliable to check for CON_ENABLED in order to identify if a console is registered. Use console_is_registered() instead. A _locked() variant is provided because uart_set_options() is always called with the console_list_lock held and must check if a console is registered in order to synchronize with kgdboc. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-23-john.ogness@linutronix.de
2022-09-25serial: Deassert Transmit Enable on probe in driver-specific wayLukas Wunner1-16/+20
When a UART port is newly registered, uart_configure_port() seeks to deassert RS485 Transmit Enable by setting the RTS bit in port->mctrl. However a number of UART drivers interpret a set RTS bit as *assertion* instead of deassertion: Affected drivers include those using serial8250_em485_config() (except 8250_bcm2835aux.c) and some using mctrl_gpio (e.g. imx.c). Since the interpretation of the RTS bit is driver-specific, it is not suitable as a means to centrally deassert Transmit Enable in the serial core. Instead, the serial core must call on drivers to deassert it in their driver-specific way. One way to achieve that is to call ->rs485_config(). It implicitly deasserts Transmit Enable. So amend uart_configure_port() and uart_resume_port() to invoke uart_rs485_config(). That allows removing calls to uart_rs485_config() from drivers' ->probe() hooks and declaring the function static. Skip any invocation of ->set_mctrl() if RS485 is enabled. RS485 has no hardware flow control, so the modem control lines are irrelevant and need not be touched. When leaving RS485 mode, reset the modem control lines to the state stored in port->mctrl. That way, UARTs which are muxed between RS485 and RS232 transceivers drive the lines correctly when switched to RS232. (serial8250_do_startup() historically raises the OUT1 modem signal because otherwise interrupts are not signaled on ancient PC UARTs, but I believe that no longer applies to modern, RS485-capable UARTs and is thus safe to be skipped.) imx.c modifies port->mctrl whenever Transmit Enable is asserted and deasserted. Stop it from doing that so port->mctrl reflects the RS232 line state. 8250_omap.c deasserts Transmit Enable on ->runtime_resume() by calling ->set_mctrl(). Because that is now a no-op in RS485 mode, amend the function to call serial8250_em485_stop_tx(). fsl_lpuart.c retrieves and applies the RS485 device tree properties after registering the UART port. Because applying now happens on registration in uart_configure_port(), move retrieval of the properties ahead of uart_add_one_port(). Link: https://lore.kernel.org/all/20220329085050.311408-1-matthias.schiffer@ew.tq-group.com/ Link: https://lore.kernel.org/all/8f538a8903795f22f9acc94a9a31b03c9c4ccacb.camel@ginzinger.com/ Fixes: d3b3404df318 ("serial: Fix incorrect rs485 polarity on uart open") Cc: stable@vger.kernel.org # v4.14+ Reported-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Reported-by: Roosen Henri <Henri.Roosen@ginzinger.com> Tested-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/2de36eba3fbe11278d5002e4e501afe0ceaca039.1663863805.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30tty: Make ->set_termios() old ktermios constIlpo Järvinen1-3/+3
There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220816115739.10928-9-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30serial: Make ->set_termios() old ktermios constIlpo Järvinen1-1/+1
There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30tty: move from strlcpy with unused retval to strscpyWolfram Sang1-1/+1
Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20220818210113.7469-1-wsa+renesas@sang-engineering.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-08Merge tag 'tty-6.0-rc1' of ↵Linus Torvalds1-156/+296
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial driver updates from Greg KH: "Here is the big set of tty and serial driver changes for 6.0-rc1. It was delayed from last week as I wanted to make sure the last commit here got some good testing in linux-next and elsewhere as it seemed to show up only late in testing for some reason. Nothing major here, just lots of cleanups from Jiri and Ilpo to make the tty core cleaner (Jiri) and the rs485 code simpler to use (Ilpo). Also included in here is the obligatory n_gsm updates from Daniel Starke and lots of tiny driver updates and minor fixes and tweaks for other smaller serial drivers. All of these have been in linux-next for a while with no reported problems" * tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (186 commits) tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements tty: amiserial: Fix comment typo tty: serial: document uart_get_console() tty: serial: serial_core, reformat kernel-doc for functions Documentation: serial: link uart_ops properly Documentation: serial: move GPIO kernel-doc to the functions Documentation: serial: dedup kernel-doc for uart functions Documentation: serial: move uart_ops documentation to the struct dt-bindings: serial: snps-dw-apb-uart: Document Rockchip RV1126 serial: mvebu-uart: uart2 error bits clearing tty: serial: fsl_lpuart: correct the count of break characters serial: stm32: make info structs static to avoid sparse warnings serial: fsl_lpuart: zero out parity bit in CS7 mode tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate. serial: 8250_bcm2835aux: Add missing clk_disable_unprepare() tty: vt: initialize unicode screen buffer serial: remove VR41XX serial driver serial: 8250: lpc18xx: Remove redundant sanity check for RS485 flags serial: 8250_dwlib: remove redundant sanity check for RS485 flags dt_bindings: rs485: Correct delay values ...
2022-07-28tty: serial: document uart_get_console()Jiri Slaby1-4/+9
This was the only function mentioned in the text, but was neither linked nor documented. So document and link it, so that hyperlinking works in the text. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220728061056.20799-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-28tty: serial: serial_core, reformat kernel-doc for functionsJiri Slaby1-54/+53
There are many annotated functions in serial_core.c, but they do not completely conform to the kernel-doc style. So reformat them and link them from the Documentation. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220728061056.20799-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-28Documentation: serial: dedup kernel-doc for uart functionsJiri Slaby1-59/+82
Some of the serial (uart_*) functions are documented twice. Once as kernel-doc along their sources and once in Documentation. So deduplicate these texts, merge them into kernel-doc in the sources, and link them using kernel-doc: from the Documentation. To be properly linked and rendered, tabulators had to be removed from the comments. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220728061056.20799-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-14serial: core: sanitize RS485 delays read from device treeLino Sanfilippo1-0/+2
Currently the RTS delays set via device tree are not clamped to a maximum value although the device tree bindings documentation for RS485 claims that only a maximum of 1000 msecs is allowed. So clamp the values to avoid arbitrary high delay settings. However clamp the values to 100 instead of 1000 msecs to be consistent which the maximum that is allowed when setting the delays from userspace via the UART ioctl TIOCSRS485. Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-6-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-14serial: core: move sanitizing of RS485 delays into own functionLino Sanfilippo1-20/+26
Move the sanitizing of RS485 delays out of uart_sanitize_serial_rs485() into the new function uart_sanitize_serial_rs485_delays(). Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-5-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-14serial: core, 8250: set RS485 termination GPIO in serial coreLino Sanfilippo1-0/+12
In serial8250_em485_config() the termination GPIO is set with the uart_port spinlock held. This is an issue if setting the GPIO line can sleep (e.g. since the concerning GPIO expander is connected via SPI or I2C). Fix this by setting the termination line outside of the uart_port spinlock in the serial core and using gpiod_set_value_cansleep() which instead of gpiod_set_value() allows it to sleep. Beside fixing the termination GPIO line setting for the 8250 driver this change also makes setting the termination GPIO generic for all UART drivers. Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-4-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-08serial: RS485 termination is supported if DT provides oneIlpo Järvinen1-0/+2
When DT provides rs485-term, set termination flag as supported. Reviewed-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220704094515.6831-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-08serial: Embed rs485_supported to uart_portIlpo Järvinen1-4/+4
Embed rs485_supported to uart_port to allow serial core to tweak it as needed. Reviewed-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220704094515.6831-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-30serial: 8250: Fix PM usage_count for console handoverIlpo Järvinen1-5/+0
When console is enabled, univ8250_console_setup() calls serial8250_console_setup() before .dev is set to uart_port. Therefore, it will not call pm_runtime_get_sync(). Later, when the actual driver is going to take over univ8250_console_exit() is called. As .dev is already set, serial8250_console_exit() makes pm_runtime_put_sync() call with usage count being zero triggering PM usage count warning (extra debug for univ8250_console_setup(), univ8250_console_exit(), and serial8250_register_ports()): [ 0.068987] univ8250_console_setup ttyS0 nodev [ 0.499670] printk: console [ttyS0] enabled [ 0.717955] printk: console [ttyS0] printing thread started [ 1.960163] serial8250_register_ports assigned dev for ttyS0 [ 1.976830] printk: console [ttyS0] disabled [ 1.976888] printk: console [ttyS0] printing thread stopped [ 1.977073] univ8250_console_exit ttyS0 usage:0 [ 1.977075] serial8250 serial8250: Runtime PM usage count underflow! [ 1.977429] dw-apb-uart.6: ttyS0 at MMIO 0x4010006000 (irq = 33, base_baud = 115200) is a 16550A [ 1.977812] univ8250_console_setup ttyS0 usage:2 [ 1.978167] printk: console [ttyS0] printing thread started [ 1.978203] printk: console [ttyS0] enabled To fix the issue, call pm_runtime_get_sync() in serial8250_register_ports() as soon as .dev is set for an uart_port if it has console enabled. This problem became apparent only recently because 82586a721595 ("PM: runtime: Avoid device usage count underflows") added the warning printout. I confirmed this problem also occurs with v5.18 (w/o the warning printout, obviously). Fixes: bedb404e91bb ("serial: 8250_port: Don't use power management for kernel console") Cc: stable <stable@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/b4f428e9-491f-daf2-2232-819928dc276e@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27serial: Support for RS-485 multipoint addressesIlpo Järvinen1-1/+21
Add support for RS-485 multipoint addressing using 9th bit [*]. The addressing mode is configured through ->rs485_config(). ADDRB in termios indicates 9th bit addressing mode is enabled. In this mode, 9th bit is used to indicate an address (byte) within the communication line. ADDRB can only be enabled/disabled through ->rs485_config() that is also responsible for setting the destination and receiver (filter) addresses. Add traps to detect unwanted changes to struct serial_rs485 layout using static_assert(). [*] Technically, RS485 is just an electronic spec and does not itself specify the 9th bit addressing mode but 9th bit seems at least "semi-standard" way to do addressing with RS485. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220624204210.11112-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27serial: take termios_rwsem for ->rs485_config() & pass termios as paramIlpo Järvinen1-4/+10
To be able to alter ADDRB within ->rs485_config(), take termios_rwsem before calling ->rs485_config() and pass termios. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220624204210.11112-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27serial: Drop timeout from uart_portIlpo Järvinen1-15/+10
Since commit 31f6bd7fad3b ("serial: Store character timing information to uart_port"), per frame timing information is available on uart_port. Uart port's timeout can be derived from frame_time by multiplying with fifosize. Most callers of uart_poll_timeout are not made under port's lock. To be on the safe side, make sure frame_time is only accessed once. As fifo_size is effectively a constant, it shouldn't cause any issues. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220613113905.22962-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-20Merge tag 'v5.19-rc3' into tty-nextGreg Kroah-Hartman1-3/+6
We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10serial: return -EINVAL for non-legacy RS485 flagsIlpo Järvinen1-0/+24
In order to be add new flags more cleanly and safely, return -EINVAL from TIOCSRS485 ioctl for the flags bits which are not among the current legacy ones. This might cause a regression for userspace as those non-flag bits do not currently trigger -EINVAL. However, it would only occur if the userspace is sending garbage bits so perhaps we'll get away with this change. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220606100433.13793-25-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10serial: Clear rs485 struct when non-RS485 mode is setIlpo Järvinen1-1/+11
When SER_RS485_ENABLED is not set, having any other flag/field set in serial_rs485 struct does not have an effect different from not having them set. Thus, make the serial_rs485 struct also match the behavior for all flags, not just SER_RS485_ENABLED. Some drivers do similar clearing of rs485 struct in their rs485_config() already, but not all. This change makes the behavior consistent across drivers. Don't try to validate rs485 struct further when no RS485 is requested, this silences some bogus warnings. This change has (minor) userspace visible impact. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220606100433.13793-24-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10serial: Sanitize rs485_structIlpo Järvinen1-4/+29
Sanitize serial_rs485 struct before calling into rs485_setup. The drivers provide supported_rs485 to help sanitization of the fields. If neither of SER_RS485_RTS_ON_SEND or SER_RS485_RTS_AFTER_SEND supported, don't pretend they can be set to sane settings but clear them both instead. If only one of them is supported it may look tempting to use the one driver supports to set the other, however, the userspace does not have that information readily available so it wouldn't be helpful. While adjusting the documentation, remove also the claim that TIOCGRS485 would call driver specific code. In reality, it does nothing else than copies the stored serial_rs485 structure from uart_port to userspace. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220606100433.13793-23-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10serial: Move serial_rs485 sanitization into separate functionIlpo Järvinen1-25/+30
Add uart_sanitize_serial_rs485() function for sanitizing serial_rs485 structure fields. No functional changes. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220606100433.13793-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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