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path: root/drivers/tty/serial/amba-pl011.c
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2014-07-09serial: amba-pl011: Remove redundant labelTushar Behera
The label 'out' is only used to return the error code. We can return the error code directly and remove 'out' label. Signed-off-by: Tushar Behera <tushar.b@samsung.com> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-19serial: Fix IGNBRK handlingPeter Hurley
If IGNBRK is set without either BRKINT or PARMRK set, some uart drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the line discipline, when it should send either nothing or the TTYBREAK flag set. This happens because the read_status_mask masks out the BI condition, which uart_insert_char() then interprets as a normal 0x00 byte. SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General Terminal Interface - Input Modes, states: "If IGNBRK is set, a break condition detected on input shall be ignored; that is, not put on the input queue and therefore not read by any process." Fix read_status_mask to include the BI bit if IGNBRK is set; the lsr status retains the BI bit if a BREAK is recv'd, which is subsequently ignored in uart_insert_char() when masked with the ignore_status_mask. Affected drivers: 8250 - all serial_txx9 mfd amba-pl010 amba-pl011 atmel_serial bfin_uart dz ip22zilog max310x mxs-auart netx-serial pnx8xxx_uart pxa sb1250-duart sccnxp serial_ks8695 sirfsoc_uart st-asc vr41xx_siu zs sunzilog fsl_lpuart sunsab ucc_uart bcm63xx_uart sunsu efm32-uart pmac_zilog mpsc msm_serial m32r_sio Unaffected drivers: omap-serial rp2 sa1100 imx icom Annotated for fixes: altera_uart mcf Drivers without break detection: 21285 xilinx-uartps altera_jtaguart apbuart arc-uart clps711x max3100 uartlite msm_serial_hs nwpserial lantiq vt8500_serial Unknown: samsung mpc52xx_uart bfin_sport_uart cpm_uart/core Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag' Reported-by: Ivan <athlon_@mail.ru> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-20tty/serial: pl011: add DT based earlycon supportRob Herring
Enable DT based earlycon initialization for the pl011 uart. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: Grant Likely <grant.likely@linaro.org>
2014-04-24tty/serial: pl011: add generic earlycon supportRob Herring
Add earlycon support for the pl011 serial port. This allows enabling the pl011 for console when early_params are processed. This is based on the arm64 earlyprintk support and is intended to replace it. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-16serial: amba-pl011: fix regression, causing an Oops on rmmodGuennadi Liakhovetski
A recent commit ef2889f7ffee67f0aed49e854c72be63f1466759 "serial: pl011: Move uart_register_driver call to device probe" introduced a regression, causing the pl011 driver to Oops if more than 1 port have been probed. Fix the Oops by only calling uart_unregister_driver() once after the last port has been removed. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-16serial: pl011: change Rx burst size to half of trigger levelGuennadi Liakhovetski
The amba-pl011.c driver sets DMA burst size equal to FIFO trigger level. If now exactly DMA burst size bytes are received, the DMAC will retrieve them all and no Rx timeout interrupt will be generated. To fix that set the burst size to half the FIFO trigger level. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13serial: pl011: Move uart_register_driver call to device probeTushar Behera
uart_register_driver call binds the driver to a specific device node through tty_register_driver call. This should typically happen during device probe call. In a multiplatform scenario, it is possible that multiple serial drivers are part of the kernel. Currently the driver registration fails if multiple serial drivers with same default major/minor numbers are included in the kernel. A typical case is observed with amba-pl011 and samsung-uart drivers. Signed-off-by: Tushar Behera <tushar.behera@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-17serial: pl011: fix fall back from DMA to interrupt modeGuennadi Liakhovetski
When falling back from DMA to interrupt mode the receive interrupt has to be re-enabled to catch new incoming data. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-17serial: pl011: (cosmetic) remove superfluous register writeGuennadi Liakhovetski
In pl011_rx_chars() if pl011_dma_rx_trigger_dma() succeeds it will disable the receive interrupt, no need to do this again. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-17serial: amba-pl011: preseserve hardware settings during initialisationJon Medhurst
During initialisation, a UART may already be in use for a console, so take care to preserve things like baud rate and data format to avoid corrupting console output. Signed-off-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-17serial: amba-pl011: factor out code for writing LCR_H registerJon Medhurst
The code to cope with a split tx/rx LCR_H register is non-trivial so put it into it's own function to avoid duplication. Signed-off-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-17serial: amba-pl011: use port lock to guard control register accessJon Medhurst
When the pl011 is being used for a console, pl011_console_write forces the control register (CR) to enable the UART for transmission and then restores this to the original value afterwards. It does this while holding the port lock. Unfortunately, when the uart is started or shutdown - say in response to userland using the serial device for a terminal - then this updates the control register without any locking. This means we can have pl011_console_write Save CR pl011_startup Initialise CR, e.g. enable receive pl011_console_write Restore old CR with receive not enabled this result is a serial port which doesn't respond to any input. A similar race in reverse could happen when the device is shutdown. We can fix these problems by taking the port lock when updating CR. Signed-off-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-17Revert "serial: pl011: use DMA RX polling by default"Greg Kroah-Hartman
This reverts commit 17438217a6f5e33d920ed3821a4b857311cc2872 on request of Linus Walleij: Greg can you please drop or revert commit 17438217a6f5e33d920ed3821a4b857311cc2872 "serial: pl011: use DMA RX polling by default" from the TTY tree until this has been sorted out? Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: pl011: use DMA RX polling by defaultLinus Walleij
Making DMA RX polling optional when DMA is on was just over-cautious: there is one single system in the kernel tree using this facility, Ux500 and after some testing I turned this on also for Ux500, which means it should simply be on by default if DMA is enabled. Cc: Jongsung Kim <neidhard.kim@lge.com> Cc: Chanho Min <chanho.min@lge.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: pl011: Convert to modern PM opsUlf Hansson
Convert to modern PM ops and use the SIMPLE_DEV_PM_OPS macro to set up the PM callbacks. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: pl011: remove redundant early amba_ports declarationBaruch Siach
This early amba_ports declaration was introduced by commit c16d51a32 (amba pl011: workaround for uart registers lockup) for use in the pl011_lockup_wa() routine. This routine was later removed by commit 4fd0690bb (serial: pl011: implement workaround for CTS clear event issue). Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-03serial: Remove unnecessary amba_set_drvdata()Michal Simek
Driver core clears the driver data to NULL after device_release or on probe failure, so just remove it from here. Driver core change: "device-core: Ensure drvdata = NULL when no driver is bound" (sha1: 0998d0631001288a5974afc0b2a5f568bcdecb4d) Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12serial: amba-pl011: Use __releases/__acquires annotationsFabio Estevam
Fix the following sparse warnings: drivers/tty/serial/amba-pl011.c:687:20: warning: context imbalance in 'pl011_dma_flush_buffer' - unexpected unlock drivers/tty/serial/amba-pl011.c:1200:13: warning: context imbalance in 'pl011_rx_chars' - unexpected unlock Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-31serial: use dev_get_platdata()Jingoo Han
Use the wrapper function for retrieving the platform data instead of accessing dev->platform_data directly. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-03Merge tag 'pinctrl-for-v3.11-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl Pull pin control changes from Linus Walleij: - A large slew of improvements of the Genric pin configuration support, and deployment in four different platforms: Rockchip, Super-H PFC, ABx500 and TZ1090. Support BIAS_BUS_HOLD, get device tree parsing and debugfs support into shape. - We also have device tree support with generic naming conventions for the generic pin configuration. - Delete the unused and confusing direct pinconf API. Now state transitions is *the* way to control pins and multiplexing. - New drivers for Rockchip, TZ1090, and TZ1090 PDC. - Two pin control states related to power management are now handled in the device core: "sleep" and "idle", removing a lot of boilerplate code in drivers. We do not yet know if this is the final word for pin PM, but it already make things a lot easier to handle. - Handle sparse GPIO ranges passing a list of disparate pins, and utilize these in the new BayTrail (x86 Atom SoC) driver. - Make the sunxi (AllWinner) driver handle external interrupts. - Make it possible for pinctrl-single to handle the case where several pins are managed by a single register, and augment it to handle sleep modes. - Cleanups and improvements for the abx500 drivers. - Move Sirf pin control drivers to their own directory, support save/restore of context and add support for the SiRFatlas6 SoC. - PMU muxing for the Dove pinctrl driver. - Finalization and support for VF610 in the i.MX6 pinctrl driver. - Smoothen out various Exynos rough edges. - Generic cleanups of various kinds. * tag 'pinctrl-for-v3.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (82 commits) pinctrl: vt8500: wmt: remove redundant dev_err call in wmt_pinctrl_probe() pinctrl: remove bindings for pinconf options needing more thought pinctrl: remove slew-rate parameter from tz1090 pinctrl: set unit for debounce time pinconfig to usec pinctrl: more clarifications for generic pull configs pinctrl: rip out the direct pinconf API pinctrl-tz1090-pdc: add TZ1090 PDC pinctrl driver pinctrl-tz1090: add TZ1090 pinctrl driver pinctrl: samsung: Staticize drvdata_list pinctrl: rockchip: Add missing irq_gc_unlock() call before return error pinctrl: abx500: rework error path pinctrl: abx500: suppress hardcoded value pinctrl: abx500: factorize code pinctrl: abx500: fix abx500_gpio_get() pinctrl: abx500: fix abx500_pin_config_set() pinctrl: abx500: Add device tree support sh-pfc: Guard DT parsing with #ifdef CONFIG_OF pinctrl: add Intel BayTrail GPIO/pinctrl support pinctrl: fix pinconf_ops::pin_config_dbg_parse_modify kerneldoc pinctrl: Staticize local symbols ... Conflicts: drivers/net/ethernet/ti/davinci_mdio.c drivers/pinctrl/Makefile
2013-06-16tty: serial: modify PL011 driver to use pinctrl PM helpersLinus Walleij
This augments the PL011 UART driver to utilize the new pinctrl core PM helpers to transition the driver to default and sleep states, cutting away some boilerplate code. Cc: Hebbar Gururaja <gururaja.hebbar@ti.com> Cc: Mark Brown <broonie@kernel.org> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-05-27Merge 3.10-rc3 into tty-nextGreg Kroah-Hartman
We want these fixes. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-20serial: pl011: protect attribute read from NULL platform data structLee Jones
It's completely feasible that platform data will be empty i.e. when booting with Device Tree with no device AUXDATA. So we must protect it's use in these use-cases, or risk a kernel Oops. Cc: Russell King <linux@arm.linux.org.uk> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Lee Jones <lee.jones@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-20tty: serial: amba-pl011: revise to use amba_rev macroJongsung Kim
This patch replaces the ugly bit-operations with the convenient amba_rev macro from the get_fifosize_arm function. The type of get_fifosize member function is also slightly changed to take a pointer to the amba_device. Signed-off-by: Jongsung Kim <neidhard.kim@lge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-07Merge tag 'cleanup-for-linus-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull ARM SoC late cleanups from Arnd Bergmann: "These are cleanups and smaller changes that either depend on earlier feature branches or came in late during the development cycle. We normally try to get all cleanups early, so these are the exceptions: - A follow-up on the clocksource reworks, hopefully the last time we need to merge clocksource subsystem changes through arm-soc. A first set of patches was part of the original 3.10 arm-soc cleanup series because of interdependencies with timer drivers now moved out of arch/arm. - Migrating the SPEAr13xx platform away from using auxdata for DMA channel descriptions towards using information in device tree, based on the earlier SPEAr multiplatform series - A few follow-ups on the Atmel SAMA5 support and other changes for Atmel at91 based on the larger at91 reworks. - Moving the armada irqchip implementation to drivers/irqchip - Several OMAP cleanups following up on the larger series already merged in 3.10." * tag 'cleanup-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (50 commits) ARM: OMAP4: change the device names in usb_bind_phy ARM: OMAP2+: Fix mismerge for timer.c between ff931c82 and da4a686a ARM: SPEAr: conditionalize SMP code ARM: arch_timer: Silence debug preempt warnings ARM: OMAP: remove unused variable serial: amba-pl011: fix !CONFIG_DMA_ENGINE case ata: arasan: remove the need for platform_data ARM: at91/sama5d34ek.dts: remove not needed compatibility string ARM: at91: dts: add MCI DMA support ARM: at91: dts: add i2c dma support ARM: at91: dts: set #dma-cells to the correct value ARM: at91: suspend both memory controllers on at91sam9263 irqchip: armada-370-xp: slightly cleanup irq controller driver irqchip: armada-370-xp: move IRQ handler to avoid forward declaration irqchip: move IRQ driver for Armada 370/XP ARM: mvebu: move L2 cache initialization in init_early() devtree: add binding documentation for sp804 ARM: integrator-cp: convert use CLKSRC_OF for timer init ARM: versatile: use OF init for sp804 timer ARM: versatile: add versatile dtbs to dtbs target ...
2013-04-20serial: amba-pl011: fix !CONFIG_DMA_ENGINE caseArnd Bergmann
I changed the prototype of the function earlier but only in the section for CONFIG_DMA_ENGINE, not the alternative. This makes the driver build again, e.g. for vexpress_defconfig. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2013-04-17ARM: PL011: add support for extended FIFO-size of PL011-r1p5Jongsung Kim
The latest r1p5-revision of the ARM PL011 UART has 32-byte FIFOs, while all earlier ones have 16-byte FIFOs. This patch suggests a way to set the FIFO-size correctly & flexibly by using a member function named get_fifosize, rather than using the fifosize member variable. The function takes the UARTPeriphID, and returns the correct FIFO size. Signed-off-by: Jongsung Kim <neidhard.kim@lge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-03amba-pl011: fix build error if CONFIG_DMA_ENGINE is not enabledChanho Min
Following patch will fix build error if CONFIG_DMA_ENGINE is unset. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Chanho Min <chanho.min@lge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-29ARM: PL011: Add support for Rx DMA buffer polling.Chanho Min
In DMA support, The received data is not pushed to tty until the DMA buffer is filled. But some megabyte rate chips such as BT expect fast response and data should be pushed immediately. In order to fix this issue, We suggest the use of the timer for polling DMA buffer. In our test, no data loss occurred at high-baudrate as compared with interrupt- driven (We tested with 3Mbps). We changes: - We add timer for polling. If we set poll_timer to 10, every 10ms, timer handler checks the residue in the dma buffer and transfer data to the tty. Also, last_residue is updated for the next polling. - poll_timeout is used to prevent the timer's system cost. If poll_timeout is set to 3000 and no data is received in 3 seconds, we inactivate poll timer and driver falls back to interrupt-driven. When data is received again in FIFO and UART irq is occurred, we switch back to DMA mode and start polling. - We use consistent DMA mappings to avoid from the frequent cache operation of the timer function for default. - pl011_dma_rx_chars is modified. the pending size is recalculated because data can be taken by polling. - the polling time is adjusted if dma rx poll is enabled but no rate is specified. Ideal polling interval to push 1 character at every interval is the reciprocal of 'baud rate / 10 line bits per character / 1000 ms per sec'. But It is very aggressive to system. Experimentally, '10000000 / baud' is suitable to receive dozens of characters. the poll rate can be specified statically by dma_rx_poll_rate of the platform data as well. Changes compared to v1: - Use of consistent DMA mappings. - Added dma_rx_poll_rate in platform data to specify the polling interval. - Added dma_rx_poll_timeout in platform data to specify the polling timeout. Changes compared to v2: - Use of consistent DMA mappings for default. - Added dma_rx_poll_enable in platform data to adjust the polling time according to the baud rate. - remove unnecessary lock from the polling function. Signed-off-by: Chanho Min <chanho.min@lge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-12serial: pl011: use generic DMA slave configuration if possibleArnd Bergmann
With the new OF DMA binding, it is possible to completely avoid the need for platform_data for configuring a DMA channel. In cases where the platform has already been converted, calling dma_request_slave_channel should get all the necessary information from the device tree. This also adds a binding document specific to the pl011 controller, and extends the generic primecell binding to mention "dmas" and other common properties. Like the patch that converts the dw_dma controller, this is completely untested and is looking for someone to try it out. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: devicetree-discuss@lists.ozlabs.org Cc: linux-arm-kernel@lists.infradead.org
2013-01-15TTY: switch tty_flip_buffer_pushJiri Slaby
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. Now, the one where most of tty_port_tty_get gets removed: tty_flip_buffer_push. IOW we also closed all the races in drivers not using tty_port_tty_get at all yet. Also we move tty_flip_buffer_push declaration from include/linux/tty.h to include/linux/tty_flip.h to all others while we are changing it anyway. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15TTY: switch tty_insert_flip_stringJiri Slaby
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. tty_insert_flip_string this time. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-25serial/amba-pl011: use devm_* managed resourcesLinus Walleij
This switches a bunch of allocation and remapping to use the devm_* garbage collected methods and cleans up the error path and remove() paths consequently. devm_ioremap() is only in <linux/io.h> so fix up the erroneous <asm/*> include as well. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Domenico Andreoli <domenico.andreoli@linux.com> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-26tty/serial/amba-pl011: Quiesce interrupts in poll_get_charAnton Vorontsov
We need to quiesce interrupts in the poll_get_char routine, otherwise, if used with KGDB NMI debugger, we'll keep reentering the NMI. Quiescing interrupts is pretty straightforward, except for TXIM interrupt. The interrupt has "ready to transmit" meaning, so it's almost always raised, and the only way to silence it is to mask it. But that's OK, ops->start_tx will unmask it. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-26tty/serial/amba-pl011: Implement poll_init callbackAnton Vorontsov
The callback is used to initialize the hardware, nothing else should be done, i.e. we should not request interrupts (but we can and do unmask some of them, as they might be useful for NMI entry). As a side-effect, the patch also fixes a division by zero[1] when booting with kgdboc options specified (e.g. kgdboc=ttyAMA0,115200n8). The issue happens because serial core calls set_termios callback, but the driver doesn't know clock frequency, and thus cannot calculate proper baud rate values. [1] WARNING: at drivers/tty/serial/serial_core.c:400 uart_get_baud_rate+0xe8/0x14c() Modules linked in: [<c0018e50>] (unwind_backtrace+0x0/0xf0) from [<c0020ae8>] (warn_slowpath_common+0x4c/0x64) [<c0020ae8>] (warn_slowpath_common+0x4c/0x64) from [<c0020b1c>] (warn_slowpath_null+0x1c/0x24) [<c0020b1c>] (warn_slowpath_null+0x1c/0x24) from [<c0185ed8>] (uart_get_baud_rate+0xe8/0x14c) [<c0185ed8>] (uart_get_baud_rate+0xe8/0x14c) from [<c0187078>] (pl011_set_termios+0x48/0x278) [<c0187078>] (pl011_set_termios+0x48/0x278) from [<c01850b0>] (uart_set_options+0xe8/0x114) [<c01850b0>] (uart_set_options+0xe8/0x114) from [<c0185de4>] (uart_poll_init+0xd4/0xe0) [<c0185de4>] (uart_poll_init+0xd4/0xe0) from [<c016da8c>] (tty_find_polling_driver+0x100/0x17c) [<c016da8c>] (tty_find_polling_driver+0x100/0x17c) from [<c0188538>] (configure_kgdboc+0xc8/0x1b8) [<c0188538>] (configure_kgdboc+0xc8/0x1b8) from [<c00088a4>] (do_one_initcall+0x30/0x168) [<c00088a4>] (do_one_initcall+0x30/0x168) from [<c033784c>] (do_basic_setup+0x94/0xc8) [<c033784c>] (do_basic_setup+0x94/0xc8) from [<c03378e0>] (kernel_init+0x60/0xf4) [<c03378e0>] (kernel_init+0x60/0xf4) from [<c00144a0>] (kernel_thread_exit+0x0/0x8) ---[ end trace 7d41c9186f342c40 ]--- Division by zero in kernel. [<c0018e50>] (unwind_backtrace+0x0/0xf0) from [<c014546c>] (Ldiv0+0x8/0x10) [<c014546c>] (Ldiv0+0x8/0x10) from [<c0187098>] (pl011_set_termios+0x68/0x278) [<c0187098>] (pl011_set_termios+0x68/0x278) from [<c01850b0>] (uart_set_options+0xe8/0x114) [<c01850b0>] (uart_set_options+0xe8/0x114) from [<c0185de4>] (uart_poll_init+0xd4/0xe0) [<c0185de4>] (uart_poll_init+0xd4/0xe0) from [<c016da8c>] (tty_find_polling_driver+0x100/0x17c) [<c016da8c>] (tty_find_polling_driver+0x100/0x17c) from [<c0188538>] (configure_kgdboc+0xc8/0x1b8) [<c0188538>] (configure_kgdboc+0xc8/0x1b8) from [<c00088a4>] (do_one_initcall+0x30/0x168) [<c00088a4>] (do_one_initcall+0x30/0x168) from [<c033784c>] (do_basic_setup+0x94/0xc8) [<c033784c>] (do_basic_setup+0x94/0xc8) from [<c03378e0>] (kernel_init+0x60/0xf4) [<c03378e0>] (kernel_init+0x60/0xf4) from [<c00144a0>] (kernel_thread_exit+0x0/0x8) Division by zero in kernel. [<c0018e50>] (unwind_backtrace+0x0/0xf0) from [<c014546c>] (Ldiv0+0x8/0x10) [<c014546c>] (Ldiv0+0x8/0x10) from [<c0183a98>] (uart_update_timeout+0x4c/0x5c) [<c0183a98>] (uart_update_timeout+0x4c/0x5c) from [<c01870f8>] (pl011_set_termios+0xc8/0x278) [<c01870f8>] (pl011_set_termios+0xc8/0x278) from [<c01850b0>] (uart_set_options+0xe8/0x114) [<c01850b0>] (uart_set_options+0xe8/0x114) from [<c0185de4>] (uart_poll_init+0xd4/0xe0) [<c0185de4>] (uart_poll_init+0xd4/0xe0) from [<c016da8c>] (tty_find_polling_driver+0x100/0x17c) [<c016da8c>] (tty_find_polling_driver+0x100/0x17c) from [<c0188538>] (configure_kgdboc+0xc8/0x1b8) [<c0188538>] (configure_kgdboc+0xc8/0x1b8) from [<c00088a4>] (do_one_initcall+0x30/0x168) [<c00088a4>] (do_one_initcall+0x30/0x168) from [<c033784c>] (do_basic_setup+0x94/0xc8) [<c033784c>] (do_basic_setup+0x94/0xc8) from [<c03378e0>] (kernel_init+0x60/0xf4) [<c03378e0>] (kernel_init+0x60/0xf4) from [<c00144a0>] (kernel_thread_exit+0x0/0x8) Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-26serial: pl011: handle corruption at high clock speedsLinus Walleij
This works around a few glitches in the ST version of the PL011 serial driver when using very high baud rates, as we do in the Ux500: 3, 3.25, 4 and 4.05 Mbps. Problem Observed/rootcause: When using high baud-rates, and the baudrate*8 is getting close to the provided clock frequency (so a division factor close to 1), when using bursts of characters (so they are abutted), then it seems as if there is not enough time to detect the beginning of the start-bit which is a timing reference for the entire character, and thus the sampling moment of character bits is moving towards the end of each bit, instead of the middle. Fix: Increase slightly the RX baud rate of the UART above the theoretical baudrate by 5%. This will definitely give more margin time to the UART_RX to correctly sample the data at the middle of the bit period. Also fix the ages old copy-paste error in the very stressed comment, it's referencing the registers used in the PL010 driver rather than the PL011 ones. Signed-off-by: Guillaume Jaunet <guillaume.jaunet@stericsson.com> Signed-off-by: Christophe Arnal <christophe.arnal@stericsson.com> Signed-off-by: Matthias Locher <matthias.locher@stericsson.com> Signed-off-by: Rajanikanth HV <rajanikanth.hv@stericsson.com> Cc: stable <stable@vger.kernel.org> Cc: Bibek Basu <bibek.basu@stericsson.com> Cc: Par-Gunnar Hjalmdahl <par-gunnar.hjalmdahl@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-10serial: pl011: delete dangling bug flagLinus Walleij
The bug flag .interrupt_may_hang is not used since commit 4fd0690bb0c3955983560bb2767ee82e2b197f9b "serial: pl011: implement workaround for CTS clear event issue" so delete it. Cc: Rajanikanth H.V <rajanikanth.hv@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-05serial: pl011: honour serial aliases in device treeMatthew Leach
If the order of UART nodes is changed in the device tree, then tty dev devices are attached to different serial ports causing the console to be directed to a different physical serial port. The "serial" aliases in the device tree should prevent this. This patch ensures that the UART driver creates tty devices that honour these aliases if a device tree is present. Acked-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Rob Herring <rob.herring@calxeda.com> Signed-off-by: Matthew Leach <matthew.leach@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-05drivers/tty/serial/amba-pl0{10,11}.c: use clk_prepare_enable and ↵Julia Lawall
clk_disable_unprepare Clk_prepare_enable and clk_disable_unprepare combine clk_prepare and clk_enable, and clk_disable and clk_unprepare. The9 make the code more concise, and ensure that clk_unprepare is called when clk_enable fails. A simplified version of the semantic patch that introduces calls to these functions is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression e; @@ - clk_prepare(e); - clk_enable(e); + clk_prepare_enable(e); @@ expression e; @@ - clk_disable(e); - clk_unprepare(e); + clk_disable_unprepare(e); // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-06Merge tty-next into 3.6-rc1Greg Kroah-Hartman
This handles the merge issue in: arch/um/drivers/line.c arch/um/drivers/line.h And resolves the duplicate patches that were in both trees do to the tty-next branch not getting merged into 3.6-rc1. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-27Merge branches 'audit', 'delay', 'fixes', 'misc' and 'sta2x11' into for-linusRussell King
2012-06-28ARM: 7433/1: serial: use the new linux/sizes.hAlessandro Rubini
Signed-off-by: Alessandro Rubini <rubini@gnudd.com> Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-06-26Merge 3.5-rc4 into tty-nextGreg Kroah-Hartman
This is to pick up the serial port and tty changes in Linus's tree to allow everyone to sync up. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-18serial/amba-pl011: fix ages old copy-paste errorsLinus Walleij
The PL011 driver has a number of symbols referring to "pl01x" (probably once shared with the pl010 driver) and some even named "pl010" (probably a pure copy-paste artifact). Lets name all local static functions with the prefix pl011_* for clarity. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-12serial/amba-pl011: move custom pin control to driverLinus Walleij
We had a boot regression in Ux500 in the merge window because two orthogonal pin control schemes for the PL011 were merged at the same time: - One using the .init() and .exit() hooks into the platform for Ux500 putting the pins into default vs sleep state respectively as the port was started/stopped. commit a09806607fd20bed2f8c41fe22793386790a14aa "ARM: ux500: switch to using pinctrl for uart0" - One hogging the default setting at PL011 probe() commit 258e055111d3cde2607e0d04eb91da2f7a59b591 "serial: amba-pl011: adopt pinctrl support" To get a solution that works for both let's scrap the stuff in the platform callbacks, instead have the driver itself select default and sleep states when the port is started/stopped. Hopefully this works for all clients. Platform callbacks are bad for device tree migration anyway, so this rids us of another problem in Ux500. Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Reported-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-22Merge tag 'tty-3.5-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull TTY updates from Greg Kroah-Hartman: "Here's the big TTY/serial driver pull request for the 3.5-rc1 merge window. Nothing major in here, just lots of incremental changes from Alan and Jiri reworking some tty core things to behave better and to get a more solid grasp on some of the nasty tty locking issues. There are a few tty and serial driver updates in here as well. All of this has been in the linux-next releases for a while with no problems. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" * tag 'tty-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (115 commits) serial: bfin_uart: Make MMR access compatible with 32 bits bf609 style controller. serial: bfin_uart: RTS and CTS MMRs can be either 16-bit width or 32-bit width. serial: bfin_uart: narrow the reboot condition in DMA tx interrupt serial: bfin_uart: Adapt bf5xx serial driver to bf60x serial4 controller. Revert "serial_core: Update buffer overrun statistics." tty: hvc_xen: NULL dereference on allocation failure tty: Fix LED error return tty: Allow uart_register/unregister/register tty: move global ldisc idle waitqueue to the individual ldisc serial8250-em: Add DT support serial8250-em: clk_get() IS_ERR() error handling fix serial_core: Update buffer overrun statistics. tty: drop the pty lock during hangup cris: fix missing tty arg in wait_event_interruptible_tty call tty/amiserial: Add missing argument for tty_unlock() tty_lock: Localise the lock pty: Lock the devpts bits privately tty_lock: undo the old tty_lock use on the ctty serial8250-em: Emma Mobile UART driver V2 Add missing call to uart_update_timeout() ...
2012-05-12serial: amba-pl011: adopt pinctrl supportShawn Guo
Cc: linux-serial@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-04-18Merge 3.4-rc3 into tty-nextGreg Kroah-Hartman
This allows us to pick up some changes needed for other serial patches. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-18serial: pl011: implement workaround for CTS clear event issueRajanikanth H.V
Problem Observed: - interrupt status is set by rising or falling edge on CTS line - interrupt status is cleared on a .0. to .1. transition of the interrupt-clear register bit 1. - interrupt-clear register is reset by hardware once the interrupt status is .0.. Remark: It seems not possible to read this register back by the CPU though, but internally this register exists. - when simultaneous set and reset event on the interrupt status happens, then the set-event has priority and the status remains .1.. As a result the interrupt-clear register is not reset to .0., and no new .0. to .1. transition can be detected on it when writing a .1. to it. This implies race condition, the clear must be performed at least one UARTCLK the riding edge of CTS RIS interrupt. Fix: Instead of resetting UART as done in commit c16d51a32bbb61ac8fd96f78b5ce2fccfe0fb4c3 "amba pl011: workaround for uart registers lockup" do the following: write .0. and then .1. to the interrupt-clear register to make sure that this transition is detected. According to the datasheet writing a .0. does not have any effect, but actually it allows to reset the internal interrupt-clear register. Take into account: The .0. needs to last at least for one clk_uart clock period (~ 38 MHz, 26.08ns) This way we can do away with the tasklet and keep only a tiny fix triggered by the variant flag introduced in this patch. Signed-off-by: Guillaume Jaunet <guillaume.jaunet@stericsson.com> Signed-off-by: Christophe Arnal <christophe.arnal@stericsson.com> Signed-off-by: Matthias Locher <Matthias.Locher@stericsson.com> Signed-off-by: Rajanikanth H.V <rajanikanth.hv@stericsson.com> Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-06serial: PL011: move interrupt clearingLinus Walleij
Commit 360f748b204275229f8398cb2f9f53955db1503b "serial: PL011: clear pending interrupts" attempts to clear interrupts by writing to a yet-unassigned memory address. This fixes the issue. The breaking patch is marked for stable so should be carried along with the other patch. Cc: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: stable <stable@vger.kernel.org> Cc: Nicolas Pitre <nico@fluxnic.net> Reported-by: Viresh Kumar <viresh.kumar@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>