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* serial: core: Include console.h from serial_core.hDouglas Anderson2018-11-091-0/+1
| | | | | | | | | | | | | In the static inline function uart_handle_break() in serial_core.h we dereference port->cons. That gives an error unless console.h is also included. This error hasn't shown up till now because everyone who has defined SUPPORT_SYSRQ has also included console.h, but it's a bit ugly to make this requirement. Let's make the include explicit. Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Allow processing sysrq at port unlock timeDouglas Anderson2018-11-091-1/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now serial drivers process sysrq keys deep in their character receiving code. This means that they've already grabbed their port->lock spinlock. This can end up getting in the way if we've go to do serial stuff (especially kgdb) in response to the sysrq. Serial drivers have various hacks in them to handle this. Looking at '8250_port.c' you can see that the console_write() skips locking if we're in the sysrq handler. Looking at 'msm_serial.c' you can see that the port lock is dropped around uart_handle_sysrq_char(). It turns out that these hacks aren't exactly perfect. If you have lockdep turned on and use something like the 8250_port hack you'll get a splat that looks like: WARNING: possible circular locking dependency detected [...] is trying to acquire lock: ... (console_owner){-.-.}, at: console_unlock+0x2e0/0x5e4 but task is already holding lock: ... (&port_lock_key){-.-.}, at: serial8250_handle_irq+0x30/0xe4 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&port_lock_key){-.-.}: _raw_spin_lock_irqsave+0x58/0x70 serial8250_console_write+0xa8/0x250 univ8250_console_write+0x40/0x4c console_unlock+0x528/0x5e4 register_console+0x2c4/0x3b0 uart_add_one_port+0x350/0x478 serial8250_register_8250_port+0x350/0x3a8 dw8250_probe+0x67c/0x754 platform_drv_probe+0x58/0xa4 really_probe+0x150/0x294 driver_probe_device+0xac/0xe8 __driver_attach+0x98/0xd0 bus_for_each_dev+0x84/0xc8 driver_attach+0x2c/0x34 bus_add_driver+0xf0/0x1ec driver_register+0xb4/0x100 __platform_driver_register+0x60/0x6c dw8250_platform_driver_init+0x20/0x28 ... -> #0 (console_owner){-.-.}: lock_acquire+0x1e8/0x214 console_unlock+0x35c/0x5e4 vprintk_emit+0x230/0x274 vprintk_default+0x7c/0x84 vprintk_func+0x190/0x1bc printk+0x80/0xa0 __handle_sysrq+0x104/0x21c handle_sysrq+0x30/0x3c serial8250_read_char+0x15c/0x18c serial8250_rx_chars+0x34/0x74 serial8250_handle_irq+0x9c/0xe4 dw8250_handle_irq+0x98/0xcc serial8250_interrupt+0x50/0xe8 ... other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&port_lock_key); lock(console_owner); lock(&port_lock_key); lock(console_owner); *** DEADLOCK *** The hack used in 'msm_serial.c' doesn't cause the above splats but it seems a bit ugly to unlock / lock our spinlock deep in our irq handler. It seems like we could defer processing the sysrq until the end of the interrupt handler right after we've unlocked the port. With this scheme if a whole batch of sysrq characters comes in one irq then we won't handle them all, but that seems like it should be a fine compromise. Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "serial:serial_core: Allow use of CTS for PPS line discipline"Greg Kroah-Hartman2018-10-041-2/+1
| | | | | | | | | | | | | This reverts commit c550f01c810f2197c98e6e3103f81797f5e063be. Turns out the samsung tty driver is mucking around in the "unused" port fields and this patch breaks that code :( So we need to fix that driver up before this can be accepted. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steve Sakoman <steve@sakoman.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty/serial_core: add ISO7816 infrastructureNicolas Ferre2018-10-021-0/+3
| | | | | | | | | | | Add the ISO7816 ioctl and associated accessors and data structure. Drivers can then use this common implementation to handle ISO7816 (smart cards). Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> [ludovic.desroches@microchip.com: squash and rebase, removal of gpios, checkpatch fixes] Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial:serial_core: Allow use of CTS for PPS line disciplineSteve Sakoman2018-10-021-1/+2
| | | | | | | | | | | | | | | | | Add a "pps_4wire" file to serial ports in sysfs in case the kernel is configured with CONFIG_PPS_CLIENT_LDISC. Writing 1 to the file enables the use of CTS instead of DCD for PPS signal input. This is necessary in case a serial port is not completely wired. Though this affects PPS processing the patch is against the serial core as the source of the serial port PPS event dispatching has to be modified. Furthermore it should be possible to modify the source of serial port PPS event dispatching before changing the line discipline. Signed-off-by: Andreas Steinmetz <ast@domdv.de> Signed-off-by: Steve Sakoman <steve@sakoman.com> Tested-by: Steve Sakoman <steve@sakoman.com> Tested-by: Eric Gallimore <egallimore@ucsd.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: 8250: introduce get_divisor() and set_divisor() hookJisheng Zhang2018-07-121-0/+7
| | | | | | | | | Add these two hooks so that they can be overridden with driver specific implementations. Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge 4.17-rc3 into tty-nextGreg Kroah-Hartman2018-04-301-7/+14
|\ | | | | | | | | | | We want the tty and serial driver fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * earlycon: Use a pointer table to fix __earlycon_table strideDaniel Kurtz2018-04-231-7/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 99492c39f39f ("earlycon: Fix __earlycon_table stride") tried to fix __earlycon_table stride by forcing the earlycon_id struct alignment to 32 and asking the linker to 32-byte align the __earlycon_table symbol. This fix was based on commit 07fca0e57fca92 ("tracing: Properly align linker defined symbols") which tried a similar fix for the tracing subsystem. However, this fix doesn't quite work because there is no guarantee that gcc will place structures packed into an array format. In fact, gcc 4.9 chooses to 64-byte align these structs by inserting additional padding between the entries because it has no clue that they are supposed to be in an array. If we are unlucky, the linker will assign symbol "__earlycon_table" to a 32-byte aligned address which does not correspond to the 64-byte aligned contents of section "__earlycon_table". To address this same problem, the fix to the tracing system was subsequently re-implemented using a more robust table of pointers approach by commits: 3d56e331b653 ("tracing: Replace syscall_meta_data struct array with pointer array") 654986462939 ("tracepoints: Fix section alignment using pointer array") e4a9ea5ee7c8 ("tracing: Replace trace_event struct array with pointer array") Let's use this same "array of pointers to structs" approach for EARLYCON_TABLE. Fixes: 99492c39f39f ("earlycon: Fix __earlycon_table stride") Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Suggested-by: Aaron Durbin <adurbin@chromium.org> Reviewed-by: Rob Herring <robh@kernel.org> Tested-by: Guenter Roeck <groeck@chromium.org> Reviewed-by: Guenter Roeck <groeck@chromium.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: core: Make sure compiler barfs for 16-byte earlycon namesDouglas Anderson2018-04-231-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As part of bringup I ended up wanting to call an earlycon driver by a name that was exactly 16-bytes big, specifically "qcom_geni_serial". Unfortunately, when I tried this I found that things compiled just fine. They just didn't work. Specifically the compiler felt perfectly justified in initting the ".name" field of "struct earlycon_id" with the full 16-bytes and just skipping the '\0'. Needless to say, that behavior didn't seem ideal, but I guess someone must have allowed it for a reason. One way to fix this is to shorten the name field to 15 bytes and then add an extra byte after that nobody touches. This should always be initted to 0 and we're golden. There are, of course, other ways to fix this too. We could audit all the users of the "name" field and make them stop at both null termination or at 16 bytes. We could also just make the name field much bigger so that we're not likely to run into this. ...but both seem like we'll just hit the bug again. Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: Introduce UPSTAT_SYNC_FIFO for synchronised FIFOsJeremy Kerr2018-04-231-0/+1
|/ | | | | | | | | | | | | This change adds a flag to indicate that a UART is has an external means of synchronising its FIFO, without needing CTSRTS or XON/XOFF. This allows us to use the throttle/unthrottle callbacks, without having to claim other methods of flow control. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Tested-by: Eddie James <eajames@linux.vnet.ibm.com> Tested-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc: Mark the variable earlycon_acpi_spcr_enable maybe_unusedMathieu Malaterre2018-03-151-1/+1
| | | | | | | | | | | | | | | | | | Re-use the object-like macro EARLYCON_USED_OR_UNUSED to mark `earlycon_acpi_spcr_enable` as maybe_unused. Fix the following warning (treated as error in W=1) CC arch/powerpc/kernel/setup-common.o In file included from ./include/linux/serial_8250.h:14:0, from arch/powerpc/kernel/setup-common.c:33: ./include/linux/serial_core.h:382:19: error: ‘earlycon_acpi_spcr_enable’ defined but not used [-Werror=unused-const-variable=] static const bool earlycon_acpi_spcr_enable; ^~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'acpi-part2-4.16-rc1' of ↵Linus Torvalds2018-02-091-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more ACPI updates from Rafael Wysocki: "These are mostly fixes and cleanups, a few new quirks, a couple of updates related to the handling of ACPI tables and ACPICA copyrights refreshment. Specifics: - Update the ACPICA kernel code to upstream revision 20180105 including: * Assorted fixes (Jung-uk Kim) * Support for X32 ABI compilation (Anuj Mittal) * Update of ACPICA copyrights to 2018 (Bob Moore) - Prepare for future modifications to avoid executing the _STA control method too early (Hans de Goede) - Make the processor performance control library code ignore _PPC notifications if they cannot be handled and fix up the C1 idle state definition when it is used as a fallback state (Chen Yu, Yazen Ghannam) - Make it possible to use the SPCR table on x86 and to replace the original IORT table with a new one from initrd (Prarit Bhargava, Shunyong Yang) - Add battery-related quirks for Asus UX360UA and UX410UAK and add quirks for table parsing on Dell XPS 9570 and Precision M5530 (Kai Heng Feng) - Address static checker warnings in the CPPC code (Gustavo Silva) - Avoid printing a raw pointer to the kernel log in the smart battery driver (Greg Kroah-Hartman)" * tag 'acpi-part2-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI: sbshc: remove raw pointer from printk() message ACPI: SPCR: Make SPCR available to x86 ACPI / CPPC: Use 64-bit arithmetic instead of 32-bit ACPI / tables: Add IORT to injectable table list ACPI / bus: Parse tables as term_list for Dell XPS 9570 and Precision M5530 ACPICA: Update version to 20180105 ACPICA: All acpica: Update copyrights to 2018 ACPI / processor: Set default C1 idle state description ACPI / battery: Add quirk for Asus UX360UA and UX410UAK ACPI: processor_perflib: Do not send _PPC change notification if not ready ACPI / scan: Use acpi_bus_get_status() to initialize ACPI_TYPE_DEVICE devs ACPI / bus: Do not call _STA on battery devices with unmet dependencies PCI: acpiphp_ibm: prepare for acpi_get_object_info() no longer returning status ACPI: export acpi_bus_get_status_handle() ACPICA: Add a missing pair of parentheses ACPICA: Prefer ACPI_TO_POINTER() over ACPI_ADD_PTR() ACPICA: Avoid NULL pointer arithmetic ACPICA: Linux: add support for X32 ABI compilation ACPI / video: Use true for boolean value
| * ACPI: SPCR: Make SPCR available to x86Prarit Bhargava2018-02-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SPCR is currently only enabled or ARM64 and x86 can use SPCR to setup an early console. General fixes include updating Documentation & Kconfig (for x86), updating comments, and changing parse_spcr() to acpi_parse_spcr(), and earlycon_init_is_deferred to earlycon_acpi_spcr_enable to be more descriptive. On x86, many systems have a valid SPCR table but the table version is not 2 so the table version check must be a warning. On ARM64 when the kernel parameter earlycon is used both the early console and console are enabled. On x86, only the earlycon should be enabled by by default. Modify acpi_parse_spcr() to allow options for initializing the early console and console separately. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Acked-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mark Salter <msalter@redhat.com> Tested-by: Mark Salter <msalter@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | serial: core: Make uart_parse_options take const char* argumentPaul Cercueil2018-01-091-1/+1
| | | | | | | | | | | | | | | | The pointed string is never modified from within uart_parse_options, so it should be marked as const in the function prototype. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: Make retrieval of rs485 properties platform-agnosticLukas Wunner2017-11-281-5/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit ef838a81dd4d ("serial: Add common rs485 device tree parsing function") consolidated retrieval of rs485 OF properties in a common helper function but did not #ifdef it to CONFIG_OF. The function is therefore included on ACPI platforms as well even though it's not used. On the other hand ACPI platforms with rs485 do exist (e.g. Siemens IOT2040) and they may leverage _DSD to store rs485 properties. Likewise, UART platform devices instantiated from an MFD should be able to specify rs485 properties. In fact, the tty subsystem maintainer had asked for a "generic" function during review of commit ef838a81dd4d: https://marc.info/?l=linux-serial&m=150143441725194&w=4 Thus, instead of constraining the helper to OF platforms, make it platform-agnostic by converting it to device_property_*() functions and renaming it accordingly. In imx.c, move the invocation of uart_get_rs485_mode() from serial_imx_probe_dt() to serial_imx_probe() so that it also gets called for non-OF devices. In omap-serial.c, move its invocation further up within serial_omap_probe_rs485() so that the RTS polarity can be overridden with the driver-specific "rs485-rts-active-high" property once we introduce a generic "rs485-rts-active-low" property. Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Lukas Wunner <lukas@wunner.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Add common rs485 device tree parsing functionUwe Kleine-König2017-09-181-0/+5
| | | | | | | | | | Several drivers have the same device tree parsing code. Create a common helper function for it. This patch bases on work done by Sascha Hauer. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: remove unneeded irq_wake flagAndy Shevchenko2017-08-281-1/+0
| | | | | | | | | There is no need to duplicate a flag which IRQ core takes care of. Replace custom flag by IRQ core API that retrieves its state. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: move UPF_NO_TXEN_TEST to quirks and renameAndy Shevchenko2017-07-301-4/+5
| | | | | | | | | | | | First 16 bits in the flags field are user-visible except UPF_NO_TXEN_TEST. To keep it clean we introduce internal quirks and move UPF_NO_TXEN_TEST to them. Rename the constant to UPQ_NO_TXEN_TEST to distinguish with port flags. Users are converted accordingly. The quirks field might be extended later to hold the additional ones. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: 8250: Add flag so drivers can avoid THRE probeJoel Stanley2017-05-181-0/+1
| | | | | | | | | | | | | The probing of THRE irq behaviour assumes the other end will be reading bytes out of the buffer in order to probe the port at driver init. In some cases the other end cannot be relied upon to read these bytes, so provide a flag for them to skip this step. Bit 19 was chosen as the flags are a int and the top bits are taken. Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: constify struct uart_port {name} fieldAndy Shevchenko2017-04-081-1/+1
| | | | | | | Don't allow modifications of port name. It's serial core's business only. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial_core: Add name field to uart_port structVignesh R2017-03-311-0/+1
| | | | | | | | | | | | | | Introduce a field to store name of uart_port that can be used to easily identify UART port instances on a system that has more than one UART instance. The name is of the form ttyXN(eg. ttyS0, ttyAMA0,..) where N is number that particular UART instance. This field will be useful when printing debug info for a particular port or in register IRQs with unique IRQ name. Port name is populated during uart_add_one_port(). Signed-off-by: Vignesh R <vigneshr@ti.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: do not accept sysrq characters via serial portFelix Fietkau2017-01-121-1/+1
| | | | | | | | | many embedded boards have a disconnected TTL level serial which can generate some garbage that can lead to spurious false sysrq detects. Signed-off-by: John Crispin <john@phrozen.org> Signed-off-by: Felix Fietkau <nbd@nbd.name> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* linux: drop __bitwise__ everywhereMichael S. Tsirkin2016-12-161-2/+2
| | | | | | | | | | | | | __bitwise__ used to mean "yes, please enable sparse checks unconditionally", but now that we dropped __CHECK_ENDIAN__ __bitwise is exactly the same. There aren't many users, replace it by __bitwise everywhere. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Stefan Schmidt <stefan@osg.samsung.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Akced-by: Lee Duncan <lduncan@suse.com>
* serial: 8250: Expose set_ldisc functionEd Blake2016-11-161-0/+2
| | | | | | | | Expose set_ldisc() function so that it can be overridden with a platform specific implementation. Signed-off-by: Ed Blake <ed.blake@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ACPI: parse SPCR and enable matching consoleAleksey Makarov2016-09-281-1/+8
| | | | | | | | | | | | | | | | | | | | | | | 'ARM Server Base Boot Requiremets' [1] mentions SPCR (Serial Port Console Redirection Table) [2] as a mandatory ACPI table that specifies the configuration of serial console. Defer initialization of DT earlycon until ACPI/DT decision is made. Parse the ACPI SPCR table, setup earlycon if required, enable specified console. Thanks to Peter Hurley for explaining how this should work. [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html [2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Tested-by: Christopher Covington <cov@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial_core: add tty NULL check to uart_tx_stoppedRob Herring2016-09-151-1/+1
| | | | | | | | | | | | | | Commit 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") created a case where a port used for a console does not get shutdown on tty closing. Then a call to uart_tx_stopped() segfaults because the tty is NULL. This could be fixed to restore old behavior, but we also want to allow tty_ports to work without a tty attached. So this change to allow a NULL tty_struct is needed either way. Fixes: 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") Reported-by: kernel test robot <xiaolong.ye@intel.com> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: earlycon: Extend earlycon command line option to support 64-bit ↵Alexander Sverdlin2016-09-021-1/+1
| | | | | | | | | | | | | | addresses earlycon implementation used "unsigned long" internally, but there are systems (ARM with LPAE) where sizeof(unsigned long) == 4 and uart is mapped beyond 4GiB address range. Switch to resource_size_t internally and replace obsoleted simple_strtoul() with kstrtoull(). Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* earlycon: mark earlycon code as __used iif the caller is built-inMasahiro Yamada2016-06-251-1/+7
| | | | | | | | | | Keep earlycon related symbols only when CONFIG_SERIAL_EARLYCON is enabled and the driver is built-in. This will be helpful to clean up ifdefs surrounding earlycon code in serial drivers. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: 8250: export get_mctrl functionWan Ahmad Zainie2016-04-301-0/+1
| | | | | | | | | | Exposes get_mctrl() function so that it can be overriden with platform specific implementation. Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Prevent unsafe uart port access, part 2Peter Hurley2016-04-301-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | For serial core operations not already excluded by holding port->mutex, use reference counting to protect deferencing the state->uart_port. Introduce helper functions, uart_port_ref() and uart_port_deref(), to wrap uart_port access, and helper macros, uart_port_lock() and uart_port_unlock(), to wrap combination uart_port access with uart port lock sections. Port removal in uart_remove_one_port() waits for reference count to drop to zero before detaching the uart port from struct uart_state. For functions only reading the tx circular buffer indexes (where the uart port lock is claimed to prevent concurrent users), a NULL uart port is simply ignored and the operation completes normally. For functions change the tx circular buffer indexes (where the uart port lock is claimed to prevent concurrent users), the operation is aborted if the uart port is NULL (ie., has been detached). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* of: earlycon: Move address translation to of_setup_earlycon()Peter Hurley2016-02-061-1/+1
| | | | | | | | | | | Cleanup the early DT/earlycon separation; remove the 'addr' parameter from of_setup_earlycon() and get the uart phys addr directly with a new wrapper function, of_flat_dt_translate_addr(). Limit fdt_translate_address() to file scope. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* of: earlycon: Initialize port fields from DT propertiesPeter Hurley2016-02-061-0/+1
| | | | | | | | | | | | | Read the optional "reg-offset", "reg-shift", "reg-io-width" and endianness properties and initialize the respective struct uart_port field if found. NB: These bindings are common to several drivers and the values merely indicate the default value; the registering earlycon setup() method can simply override the values if required. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* of: earlycon: Add options string handlingPeter Hurley2016-02-061-1/+2
| | | | | | | | | Pass-through any options string in the 'stdout-path' property to the earlycon "driver" setup. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* of: earlycon: Fixup earlycon console name and indexPeter Hurley2016-02-061-2/+1
| | | | | | | | | | Use the console name embedded in the OF earlycon table by the OF_EARLYCON_DECLARE() macro to initialize the struct console 'name' and 'index' fields. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* earlycon: Use common framework for earlycon declarationsPeter Hurley2016-02-061-9/+13
| | | | | | | | | | | | | | | | | | | | | | Use a single common table of struct earlycon_id for both command line and devicetree. Re-define OF_EARLYCON_DECLARE() macro to instance a unique earlycon declaration (the declaration is only guaranteed to be unique within a compilation unit; separate compilation units must still use unique earlycon names). The semantics of OF_EARLYCON_DECLARE() is different; it declares an earlycon which can matched either on the command line or by devicetree. EARLYCON_DECLARE() is semantically unchanged; it declares an earlycon which is matched by command line only. Remove redundant instances of EARLYCON_DECLARE(). This enables all earlycons to properly initialize struct console with the appropriate name and index, which improves diagnostics and enables direct earlycon-to-console handoff. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Fix UPIO_MEM commentPeter Hurley2015-12-131-1/+1
| | | | | | | | | | | | | | The original semantics of UPIO_MEM did not include the notion of bitness and endianness; different drivers used UPIO_MEM to refer to their original mmio bitness/endianness. For example, for the 8250 driver this is 8-bit LE but for the amba-pl011 driver this is 16-bit LE. Since UPIO_* values are userspace ABI via TIOCGSERIAL/TIOCSSERIAL ioctls, the original meaning of UPIIO_MEM must remain as it was: the original mmio stride/width/endianness of the driver. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Timur Tabi <timur@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: support 16-bit register interface for consoleMasahiro Yamada2015-12-131-0/+1
| | | | | | | | | | | | Currently, 8-bit (MMIO) and 32-bit (MMIO32) register interfaces are supported for the 8250 console, but the 16-bit (MMIO16) is not. The 8250 UART device on my board is connected to a 16-bit bus and my main motivation is to use earlycon with it. (Refer to arch/arm/boot/dts/uniphier-support-card.dtsi) Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Fix unused variable warnings from uart_console()Peter Hurley2015-05-061-1/+1
| | | | | | | | | | | | | | | | If CONFIG_SERIAL_CORE_CONSOLE=n, build warnings are generated by uart_console() macro expansion: drivers/tty/serial/of_serial.c: In function ‘of_serial_suspend_8250’: drivers/tty/serial/of_serial.c:262:20: warning: unused variable ‘port’ [-Wunused-variable] struct uart_port *port = &port8250->port; ^ drivers/tty/serial/of_serial.c: In function ‘of_serial_resume_8250’: drivers/tty/serial/of_serial.c:272:20: warning: unused variable ‘port’ [-Wunused-variable] struct uart_port *port = &port8250->port; Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* earlycon: Fix __earlycon_table stridePeter Hurley2015-04-101-1/+1
| | | | | | | | | | | The compiler and the linker must agree on the alignment of struct earlycon_id; empirical testing and commit 07fca0e57fca92 ("tracing: Properly align linker defined symbols") suggests 32-byte alignment is the LCD. Reported-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: 8250: allow specifying iomem size in addition to addressMans Rullgard2015-03-261-0/+1
| | | | | | | | | This adds a mapsize field to struct uart_port to be used in conjunction with mapbase. If set, it overrides whatever value serial8250_port_size() would otherwise report. Signed-off-by: Mans Rullgard <mans@mansr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: earlycon: Enable earlycon without command line paramPeter Hurley2015-03-261-8/+11
| | | | | | | | | | | | | | | | | | | | | | | Earlycon matching can only be triggered if 'earlycon=...' has been specified on the kernel command line. To workaround this limitation requires tight coupling between arches and specific serial drivers in order to start an earlycon. Devicetree avoids this limitation with a link table that contains the required data to match earlycons. Mirror this approach for earlycon match by name. Re-purpose EARLYCON_DECLARE to generate a table entry which associates name with setup() function. Re-purpose setup_earlycon() to scan this table for an earlycon match, which is registered if found. Declare one "earlycon" early_param, which calls setup_earlycon(). This design allows setup_earlycon() to be called directly with a param string (as if 'earlycon=...' had been set on the command line). Re-registration (either directly or by early_param) is prevented. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Add minor field to uart_portPeter Hurley2015-03-261-0/+1
| | | | | | | | | | | | | | UART drivers that share ttyS namespace cannot trivially compute the ttyS index from the port->line value since the minor_start may be offset from minor 64. Further, to do so requires a pointer to the uart driver since there is no back pointer from uart_port to uart_driver. Rather than have UART drivers computing the minor value by themselves, encapsulate within the serial core at port registration time. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge 4.0-rc3 into tty-testingGreg Kroah-Hartman2015-03-091-0/+2
|\ | | | | | | | | | | This resolves a merge issue in drivers/tty/serial/8250/8250_pci.c Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: earlycon: Refactor parse_options into serial corePeter Hurley2015-03-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Prepare to support console-defined matching; refactor the command line parameter string processing from parse_options() into a new core function, uart_parse_earlycon(), which decodes command line parameters of the form: earlycon=<name>,io|mmio|mmio32,<addr>,<options> console=<name>,io|mmio|mmio32,<addr>,<options> earlycon=<name>,0x<addr>,<options> console=<name>,0x<addr>,<options> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: uapi: Declare all userspace-visible io typesPeter Hurley2015-03-071-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | ioctl(TIOCGSERIAL|TIOCSSERIAL) report and can change the port->iotype. UART drivers use the UPIO_* definitions, but the uapi header defines parallel values and userspace uses these parallel values for ioctls; thus the userspace values are definitive. Define UPIO_* iotypes in terms of the uapi defines, SERIAL_IO_*; extend the uapi defines to include all values in use by the serial core. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: core: Fix iotype userspace breakagePeter Hurley2015-03-071-3/+3
|/ | | | | | | | | | | | | commit 3ffb1a8193bea ("serial: core: Add big-endian iotype") re-numbered userspace-dependent values; ioctl(TIOCSSERIAL) can assign the port iotype (which is expected to match the selected i/o accessors), so iotype values must not be changed. Cc: Kevin Cernekee <cernekee@gmail.com> Cc: <stable@vger.kernel.org> # 3.19+ Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Reviewed-by: Kevin Cernekee <cernekee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Rework hw-assisted flow control supportPeter Hurley2015-02-021-3/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hw-assisted flow control support was added to the serial core in v3.8 with commits, dba05832cbe4f ("SERIAL: core: add hardware assisted h/w flow control support") 2cbacafd7af0f ("SERIAL: core: add hardware assisted s/w flow control support") 9aba8d5b01119 ("SERIAL: core: add throttle/unthrottle callbacks for hardware assisted flow control") Since then, additional requirements for serial core support have arisen. Specifically, 1. Separate tx and rx flow control settings for UARTs which only support tx flow control (ie., autoCTS). 2. Disable sw-assisted CTS flow control in autoCTS mode 3. Support for RTS flow control by serial core and userspace in autoRTS mode Distinguish mode from capability; introduce UPSTAT_AUTORTS, UPSTAT_AUTOCTS and UPSTAT_AUTOXOFF which, when set by the uart driver, enable serial core support for hw-assisted rx, hw-assisted tx and hw-assisted in-band/IXOFF rx flow control, respectively. [Note: hw-assisted in-band/IXON tx flow control does not require serial core support/intervention and can be enabled by the uart driver when required.] These modes must be set/reset in the driver's set_termios() method, based on termios settings, and thus can be safely queried in any context in which one of the port lock, port mutex or termios rwsem are held. Set these modes in the 2 in-tree drivers, omap-serial and 8250_omap, which currently use UPF_HARD_FLOW/UPF_SOFT_FLOW support. Retain UPF_HARD_FLOW and UPF_SOFT_FLOW as capabilities; re-define UPF_HARD_FLOW as both UPF_AUTO_RTS and UPF_AUTO_CTS to allow for distinct and separate rx and tx flow control capabilities. Disable sw-assisted CTS flow control when UPSTAT_AUTOCTS is enabled. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: omap_8250: Fix RTS handlingPeter Hurley2015-01-091-0/+1
| | | | | | | | | | | | | | | | | | | The OMAP3 UART ignores MCR[1] (ie., UART_MCR_RTS) when in autoRTS mode (UPF_HARD_FLOW + CRTSCTS). This makes it impossible for either the serial core or userspace to manually flow control the sender. Disable autoRTS mode when RTS is lowered and restore the previous mode when RTS is raised. Note that the OMAP3 UART provides no mechanism for switching from autoRTS mode without corrupting incoming data; to access the necessary register, the line control settings must be set to 8-e-2 and thus any data received during that time will be interpreted with those settings. This corruption has been observed in practice. Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Add big-endian iotypeKevin Cernekee2014-11-251-6/+7
| | | | | | | | | Since most drivers interpret UPIO_MEM32 to mean "little-endian" and use readl/writel to access the registers, add a parallel UPIO_MEM32BE to request the use of big-endian MMIO accessors (ioread32be/iowrite32be). Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial_core: Handle TIOC[GS]RS485 ioctls.Ricardo Ribalda Delgado2014-11-061-0/+3
| | | | | | | | | | | | | | | | | | | | | The following drivers: 8250_core, atmel_serial, max310x, mcf, omap-serial and sci16is7xx implement code to handle RS485 ioctls. In order to avoid code duplication, we implement a simple ioctl handler on the serial_core layer. This handler can be used by all the other drivers instead of duplicating code. Until this is the only RS485 ioctl handler, it will try first the rs485_config callback and if it is not present it will call the driver specific ioctl. Reviewed-by: Alan Cox <alan@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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