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2015-07-24serial: core: Fix crashes while echoing when closingPeter Hurley1-1/+2
While closing, new rx data may be received after the input buffers have been flushed but before stop_rx() halts receiving [1]. The new data might not be processed by flush_to_ldisc() until after uart_shutdown() and normal input processing is re-enabled (ie., tty->closing = 0). The race is outlined below: CPU 0 | CPU 1 | uart_close() | tty_port_close_start() | tty->closing = 1 | tty_ldisc_flush() | | => IRQ | while (LSR & data ready) | uart_insert_char() | tty_flip_buffer_push() | <= EOI stop_rx() | . uart_shutdown() | . free xmit.buf | . tty_port_tty_set(NULL) | . tty->closing = 0 | . | flush_to_ldisc() | n_tty_receive_buf_common() | __receive_buf() | ... | commit_echoes() | uart_flush_chars() | __uart_start() | ** OOPS on port.tty deref ** tty_ldisc_flush() | Input processing must be prevented from echoing (tty->closing = 1) until _after_ the input buffers have been flushed again at the end of uart_close(). [1] In fact, some input may actually be buffered _after_ stop_rx() since the rx interrupt may have already triggered but not yet been handled when stop_rx() disables rx interrupts. Fixes: 2e758910832d ("serial: core: Flush ldisc after dropping port mutex in uart_close()") Reported-by: Robert Elliott <elliott@hp.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-24Revert "serial: imx: initialized DMA w/o HW flow enabled"David Jander1-8/+7
This reverts commit 068500e08dc87ea9a453cc4a500cf3ab28d0f936. According to some tests, SDMA support is broken at least for i.MX6 without HW flow control. Different forms of data-corruption appear either with the ROM firmware for the SDMA controller as well as when loading Freescale provided SDMA firmware versions 1.1 or 3.1. Signed-off-by: David Jander <david@protonic.nl> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-24sc16is7xx: fix FIFO address of secondary UARTBo Svangård1-7/+23
Calls to regmap_raw_read/write needed register rewrite in a similar way as function calls to regmap_read/write already had. This enables reading/writing the serial datastream to the device. Signed-off-by: Bo Svangård <bo.svangard@embeddedart.se> Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Jon Ringle <jringle@gridpoint.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-24sc16is7xx: fix Kconfig dependenciesJakub Kicinski1-1/+1
When I2C=m and SPI=y or-ing them will produce =y while what we need is the lower bound, i.e. =m. Fortunately SPI is a boolean so we need to handle only one special case. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-24serial: etraxfs-uart: Fix release etraxfs_uart_portsAxel Lin1-1/+1
In probe, we use dev_id as array index of etraxfs_uart_ports and store the index in port->line. So etraxfs_uart_ports[port->line] should be released when unload the module. Signed-off-by: Axel Lin <axel.lin@ingics.com> Acked-by: Niklas Cassel <nks@flawful.org> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-24serial: amba-pl011: Fix devm_ioremap_resource return value checkKrzysztof Kozlowski1-2/+2
Value returned by devm_ioremap_resource() was checked for non-NULL but devm_ioremap_resource() returns IOMEM_ERR_PTR, not NULL. In case of error this could lead to dereference of ERR_PTR. Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com> Cc: <stable@vger.kernel.org> Fixes: 3873e2d7f63a ("drivers: PL011: refactor pl011_probe()") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-03Merge tag 'armsoc-late' of ↵Linus Torvalds2-85/+8
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull ARM SoC late fixes and dependencies from Kevin Hilman: "This is a collection of a few late fixes and other misc stuff that had dependencies on things being merged from other trees. Other than the fixes, the primary feature being added is the conversion of some OMAP drivers to the new generic wakeirq interface" * tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: ARM: multi_v7_defconfig: Enable BRCMNAND driver ARM: BCM: Do not select CONFIG_MTD_NAND_BRCMNAND ARM: at91/dt: update udc compatible strings ARM: at91/dt: trivial: fix USB udc compatible string arm64: dts: Add APM X-Gene standby GPIO controller DTS entries soc: qcom: spm: Fix idle on THUMB2 kernels ARM: dove: fix legacy dove IRQ numbers ARM: mvebu: fix suspend to RAM on big-endian configurations ARM: mvebu: adjust Armada XP DT spi muxing after pinctrl function rename serial: 8250_omap: Move wake-up interrupt to generic wakeirq serial: omap: Switch wake-up interrupt to generic wakeirq mmc: omap_hsmmc: Change wake-up interrupt to use generic wakeirq
2015-06-27Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds3-0/+278
Pull MIPS updates from Ralf Baechle: - Improvements to the tlb_dump code - KVM fixes - Add support for appended DTB - Minor improvements to the R12000 support - Minor improvements to the R12000 support - Various platform improvments for BCM47xx - The usual pile of minor cleanups - A number of BPF fixes and improvments - Some improvments to the support for R3000 and DECstations - Some improvments to the ATH79 platform support - A major patchset for the JZ4740 SOC adding support for the CI20 platform - Add support for the Pistachio SOC - Minor BMIPS/BCM63xx platform support improvments. - Avoid "SYNC 0" as memory barrier when unlocking spinlocks - Add support for the XWR-1750 board. - Paul's __cpuinit/__cpuinitdata cleanups. - New Malta CPU board support large memory so enable ZONE_DMA32. * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (131 commits) MIPS: spinlock: Adjust arch_spin_lock back-off time MIPS: asmmacro: Ensure 64-bit FP registers are used with MSA MIPS: BCM47xx: Simplify handling SPROM revisions MIPS: Cobalt Don't use module_init in non-modular MTD registration. MIPS: BCM47xx: Move NVRAM driver to the drivers/firmware/ MIPS: use for_each_sg() MIPS: BCM47xx: Don't select BCMA_HOST_PCI MIPS: BCM47xx: Add helper variable for storing NVRAM length MIPS: IRQ/IP27: Move IRQ allocation API to platform code. MIPS: Replace smp_mb with release barrier function in unlocks. MIPS: i8259: DT support MIPS: Malta: Basic DT plumbing MIPS: include errno.h for ENODEV in mips-cm.h MIPS: Define GCR_GIC_STATUS register fields MIPS: BPF: Introduce BPF ASM helpers MIPS: BPF: Use BPF register names to describe the ABI MIPS: BPF: Move register definition to the BPF header MIPS: net: BPF: Replace RSIZE with SZREG MIPS: BPF: Free up some callee-saved registers MIPS: Xtalk: Update xwidget.h with known Xtalk device numbers ...
2015-06-27Merge tag 'tty-4.2-rc1' of ↵Linus Torvalds46-1367/+2895
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here's the tty and serial driver patches for 4.2-rc1. A number of individual driver updates, some code cleanups, and other minor things, full details in the shortlog. All have been in linux-next for a while with no reported issues" * tag 'tty-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (152 commits) Doc: serial-rs485.txt: update RS485 driver interface Doc: tty.txt: remove mention of the BKL MAINTAINERS: tty: add serial docs directory serial: sprd: check for NULL after calling devm_clk_get serial: 8250_pci: Correct uartclk for xr17v35x expansion chips serial: 8250_pci: Add support for 12 port Exar boards serial: 8250_uniphier: add bindings document for UniPhier UART serial: core: cleanup in uart_get_baud_rate() serial: stm32-usart: Add STM32 USART Driver tty/serial: kill off set_irq_flags usage tty: move linux/gsmmux.h to uapi doc: dt: add documentation for nxp,lpc1850-uart serial: 8250: add LPC18xx/43xx UART driver serial: 8250_uniphier: add UniPhier serial driver serial: 8250_dw: support ACPI platforms with integrated DMA engine serial: of_serial: check the return value of clk_prepare_enable() serial: of_serial: use devm_clk_get() instead of clk_get() serial: earlycon: Add support for big-endian MMIO accesses serial: sirf: use hrtimer for data rx serial: sirf: correct the fifo empty_bit ...
2015-06-25Merge tag 'for-4.2' of git://git.sourceforge.jp/gitroot/uclinux-h8/linuxLinus Torvalds2-22/+20
Pull Renesas H8/300 architecture re-introduction from Yoshinori Sato. We dropped arch/h8300 two years ago as stale and old, this is a new and more modern rewritten arch support for the same architecture. * tag 'for-4.2' of git://git.sourceforge.jp/gitroot/uclinux-h8/linux: (27 commits) h8300: fix typo. h8300: Always build dtb h8300: Remove ARCH_WANT_IPC_PARSE_VERSION sh-sci: Get register size from platform device clk: h8300: fix error handling in h8s2678_pll_clk_setup() h8300: Symbol name fix h8300: devicetree source h8300: configs h8300: IRQ chip driver h8300: clocksource h8300: clock driver h8300: Build scripts h8300: library functions h8300: Memory management h8300: miscellaneous functions h8300: process helpers h8300: compressed image support h8300: Low level entry h8300: kernel startup h8300: Interrupt and exceptions ...
2015-06-23Merge tag 'gpio-v4.2-1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio Pull gpio updates from Linus Walleij: "This is the big bulk of GPIO changes queued for the v4.2 kernel series: - a big set of cleanups to the aged sysfs interface from Johan Hovold. To get these in, v4.1-rc3 was merged into the tree as the first patch in that series had to go into stable. This makes the locking much more fine-grained (get rid of the "big GPIO lock(s)" and store states in the GPIO descriptors. - rename gpiod_[g|s]et_array() to gpiod_[g|s]et_array_value() to avoid confusions. - New drivers for: * NXP LPC18xx (currently LPC1850) * NetLogic XLP * Broadcom STB SoC's * Axis ETRAXFS * Zynq Ultrascale+ (subdriver) - ACPI: * make it possible to retrieve GpioInt resources from a GPIO device using acpi_dev_gpio_irq_get() * merge some dependent I2C changes exploiting this. * support the ARM X-Gene GPIO standby driver. - make it possible for the generic GPIO driver to read back the value set registers to reflect current status. - loads of OMAP IRQ handling fixes. - incremental improvements to Kona, max732x, OMAP, MXC, RCAR, PCA953x, STP-XWAY, PCF857x, Crystalcove, TB10x. - janitorial (constification, checkpatch cleanups)" * tag 'gpio-v4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (71 commits) gpio: Fix checkpatch.pl issues gpio: pcf857x: handle only enabled irqs gpio / ACPI: Return -EPROBE_DEFER if the gpiochip was not found GPIO / ACPI: export acpi_gpiochip_request(free)_interrupts for module use gpio: improve error reporting on own descriptors gpio: promote own request failure to pr_err() gpio: Added support to Zynq Ultrascale+ MPSoC gpio: add ETRAXFS GPIO driver fix documentation after renaming gpiod_set_array to gpiod_set_array_value gpio: Add GPIO support for Broadcom STB SoCs gpio: xgene: add ACPI support for APM X-Gene GPIO standby driver gpio: tb10x: Drop unneeded free_irq() call gpio: crystalcove: set IRQCHIP_SKIP_SET_WAKE for the irqchip gpio: stp-xway: Use the of_property_read_u32 helper gpio: pcf857x: Check for irq_set_irq_wake() failures gpio-stp-xway: Fix enabling the highest bit of the PHY LEDs gpio: Prevent an integer overflow in the pca953x driver gpio: omap: rework omap_gpio_irq_startup to handle current pin state properly gpio: omap: rework omap_gpio_request to touch only gpio specific registers gpio: omap: rework omap_x_irq_shutdown to touch only irqs specific registers ...
2015-06-23sh-sci: Get register size from platform deviceYoshinori Sato1-21/+13
There is much SCI of SoC having within, and the register size is also different in everyone. So get from platform device. Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp> Acked-by: by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
2015-06-23sh-sci: Add h8300 SCIYoshinori Sato2-1/+7
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
2015-06-21serial: 8250_ingenic: support for Ingenic SoC UARTsPaul Burton3-0/+278
Introduce a driver suitable for use with the UARTs present in Ingenic SoCs such as the JZ4740 & JZ4780. These are described as being ns16550 compatible but aren't quite - they require the setting of an extra bit in the FCR register to enable the UART module. The serial_out implementation is the same as that in arch/mips/jz4740/serial.c - which will shortly be removed. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: linux-serial@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Alan Cox <alan@linux.intel.com> Cc: linux-kernel@vger.kernel.org Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Cc: Tony Lindgren <tony@atomide.com> Cc: John Crispin <blogic@openwrt.org> Patchwork: https://patchwork.linux-mips.org/patch/10159/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-06-13serial: sprd: check for NULL after calling devm_clk_getFernando Guzman Lugo1-1/+1
In platforms which does not use CLK framework (HAVE_CLK not set), the clk_* functions return NULL instead of an error. This patch handles that scenario. Signed-off-by: Fernando Guzman Lugo <fernando.guzman.lugo@intel.com> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-13serial: 8250_pci: Correct uartclk for xr17v35x expansion chipsSoeren Grunewald1-3/+19
The internal clock of the master chip, which is usually 125MHz, is only half (62.5MHz) for the slave chips. So we have to adjust the uartclk for all the slave ports. Therefor we add a new function to determine if a slave chip is present and update pci_xr17v35x_setup accordingly. Signed-off-by: Soeren Grunewald <soeren.grunewald@desy.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-13serial: 8250_pci: Add support for 12 port Exar boardsSoeren Grunewald1-0/+21
The Exar XR17V358 can also be combined with a XR17V354 chip to act as a single 12 port chip. This works the same way as the combining two XR17V358 chips. But the reported device id then is 0x4358. Signed-off-by: Soeren Grunewald <soeren.grunewald@desy.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-13serial: core: cleanup in uart_get_baud_rate()Joakim Nordell1-5/+16
Align with coding guidelines: Replaced a chain of "else if" by a switch case. Signed-off-by: Joakim Nordell <joakim.nordell@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-11serial: stm32-usart: Add STM32 USART DriverMaxime Coquelin3-0/+757
This drivers adds support to the STM32 USART controller, which is a standard serial driver. Tested-by: Chanwoo Choi <cw00.choi@samsung.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Reviewed-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-10serial: 8250_omap: Move wake-up interrupt to generic wakeirqTony Lindgren1-54/+4
We can now use generic wakeirq handling and remove the custom handling for the wake-up interrupts. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tony Lindgren <tony@atomide.com>
2015-06-10serial: omap: Switch wake-up interrupt to generic wakeirqTony Lindgren1-31/+4
We can now use generic wakeirq handling and remove the custom handling for the wake-up interrupts. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tony Lindgren <tony@atomide.com>
2015-06-09tty/serial: kill off set_irq_flags usageRob Herring2-4/+4
set_irq_flags is ARM specific with custom flags which have genirq equivalents. Convert drivers to use the genirq interfaces directly, so we can kill off set_irq_flags. The translation of flags is as follows: IRQF_VALID -> !IRQ_NOREQUEST IRQF_PROBE -> !IRQ_NOPROBE IRQF_NOAUTOEN -> IRQ_NOAUTOEN For IRQs managed by an irqdomain, the irqdomain core code handles clearing and setting IRQ_NOREQUEST already, so there is no need to do this in .map() functions and we can simply remove the set_irq_flags calls. Some users also set IRQ_NOPROBE and this has been maintained although it is not clear that is really needed. There appears to be a great deal of blind copy and paste of this code. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Barry Song <baohua@kernel.org> Cc: linux-serial@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-08Merge 4.1-rc7 into tty-nextGreg Kroah-Hartman1-0/+8
This fixes up a merge issue with the amba-pl011.c driver, and we want the fixes in this branch as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01gpiolib: rename gpiod_set_array to gpiod_set_array_valueRojhalat Ibrahim1-1/+1
There have been concerns that the function names gpiod_set_array() and gpiod_get_array() might be confusing to users. One might expect gpiod_get_array() to return array values, while it is actually the array counterpart of gpiod_get(). To be consistent with the single descriptor API we could rename gpiod_set_array() to gpiod_set_array_value(). This makes some function names a bit lengthy: gpiod_set_raw_array_value_cansleep(). Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-01serial: 8250_omap: provide complete custom startup & shutdown callbacksSebastian Andrzej Siewior1-9/+73
The currently in-use port->startup and port->shutdown are "okay". The startup part for instance does the tiny omap extra part and invokes serial8250_do_startup() for the remaining pieces. The workflow in serial8250_do_startup() is okay except for the part where UART_RX is read without a check if there is something to read. I tried to workaround it in commit 0aa525d11859 ("tty: serial: 8250_core: read only RX if there is something in the FIFO") but then reverted it later in commit ca8bb4aefb9 ("serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is something in the FIFO""). This is the second attempt to get it to work on older OMAPs without breaking other chips this time Peter Hurley suggested to pull in the few needed lines from serial8250_do_startup() and drop everything else that is not required including making it simpler like using just request_irq() instead the chain handler like it is doing now. So lets try that. Fixes: ca8bb4aefb93 ("serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is something in the FIFO"") Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01serial: 8250: add LPC18xx/43xx UART driverJoachim Eastwood3-0/+239
Serial port driver for the 8250-based UART found on LPC18xx/43xx devices. The UART is 16550A compatible with additional features like RS485 support, synchronous mode, IrDA, and DMA. For now only basic UART and RS485 operation is supported. Signed-off-by: Joachim Eastwood <manabian@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01serial: 8250_uniphier: add UniPhier serial driverMasahiro Yamada3-0/+265
Add the driver for on-chip UART used on UniPhier SoCs. This hardware is similar to 8250, but the register mapping is slightly different: - The offset to FCR, MCR is different. - The divisor latch access bit does not exist. Instead, the divisor latch register is available at offset 9. This driver overrides serial_{in,out}, dl_{read,write} callbacks, but wants to borrow most of code from 8250_core.c. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01serial: 8250_dw: support ACPI platforms with integrated DMA engineHeikki Krogerus1-1/+18
On many new Intel SoCs the UART has an integrated DMA engine (iDMA). In order to use it a special filter function is needed. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01serial: of_serial: check the return value of clk_prepare_enable()Masahiro Yamada1-1/+4
The function clk_prepare_enable() may fail, and in that case it does not make sense to proceed. Let's check its return code and error out if it is a negative value. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01serial: of_serial: use devm_clk_get() instead of clk_get()Masahiro Yamada1-1/+1
The probe method of this driver calls clk_get(), but clk_put() is missing from the remove callback. Using the managed clk function is easier than fixing other parts. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01serial: earlycon: Add support for big-endian MMIO accessesNoam Camus2-5/+11
Support command line parameters of the form: earlycon=<name>,io|mmio|mmio32|mmio32be,<addr>,<options> This commit seem to be needed even after commit: serial: 8250: Add support for big-endian MMIO accesses c627f2ceb692e8a9358b64ac2d139314e7bb0d17 Signed-off-by: Noam Camus <noamc@ezchip.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01serial: sirf: use hrtimer for data rxQipan Li2-226/+135
when the serial works as a bluetooth sink, due to audio realtime requirement, the driver should have something similar with ALSA: 1. one big DMA buffer to easy the schedule jitter 2. split this big DMA buffer to multiple small periods, for each period, we get a DMA interrupt, then push the data to userspace. the small periods will easy the audio latency. so ALSA generally uses a cyclic chained DMA. but for sirfsoc, the dma hardware has the limitation: we have only two loops in the cyclic mode, so we can only support two small periods to switch. if we make the DMA buffer too big, we get long latency, if we make the DMA buffer too little, we get miss in scheduling for audio realtime. so this patch moves to use a hrtimer to simulate the cyclic DMA, then we can have a big buffer, and also have a timely data push to users as the hrtimer can generate in small period then actual HW interrupts. with this patch, we also delete a lot of complex codes to handle loop buffers, and RX timeout interrupt since the RX work can be completely handled from hrtimer interrupt. tests show using this way will make our bad audio streaming be- come smooth. Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01serial: sirf: correct the fifo empty_bitQipan Li1-1/+1
Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01serial: sirf: fix system hung on console log outputQipan Li1-1/+1
A corner case exists in the current driver. if an app opens the console device, and before writing to console device, and there are huge kernel ogs to print out, system will hang on sirfsoc_uart_console_putchar: while (rd_regl(port, ureg->sirfsoc_tx_fifo_status) & ufifo_st->ff_full(port->line)) cpu_relax(); as in sirfsoc_uart_startup(), the driver assigns tx_fifo_op to 0 will stop TX FIFO, this loop will be endless. Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01serial: 8250: remove return statements from void functionMasahiro Yamada1-2/+3
serial8250_set_mctrl() is a void type function. Returning something does not look nice. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01sc16is7xx: use kworker for RS-485 configurationJakub Kicinski1-12/+29
RS-485 configuration is also done under the spinlock so no blocking I/O allowed. Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01sc16is7xx: use kworker to update ier bitsJakub Kicinski1-10/+19
.stop_rx/tx() are called in atomic context, we cannot use blocking I/O. While at it correct the name of RX bit and '*' placement in pointer declarations. Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01sc16is7xx: use kworker for md_procJakub Kicinski1-16/+31
Convert md_proc into general async reconfiguration procedure. Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01sc16is7xx: move RTS delay to workqueueJakub Kicinski1-8/+6
Instead of spinning under port->lock let's just sleep inside the kthread. It should be equivalent as TX cannot proceed when thread is blocked. Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01sc16is7xx: use kthread_worker for tx_work and irqJakub Kicinski1-23/+43
Convert workqueue usage to a real-time kworker. The problem with workqueues is that we cannot set real-time priorities on our work and asynchronous reconfiguration can be blocked by less important tasks. We need kthread for the interrupt anyway and because we will now be using single kthread for all TX-related operations we can get rid of the port mutex. Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01sc16is7xx: use LSR_TEMT_BIT in .tx_empty()Jakub Kicinski1-3/+2
LSR_TEMT_BIT (LSR bit 6) provides us exactly the information we need to determine if transmission is finished - FIFO level and shift register empty. We can save ourselves reading FIFO level explicitly if we use this bit. Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01sc16is7xx: add missing compatible stringsJakub Kicinski1-0/+4
Without matching bus-specific strings driver will not be loaded automatically. Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01sc16is7xx: remove RS-485 delay RTS handlingJakub Kicinski1-15/+8
Users of RS-485 can request via ioctl that RTS signals should be activated selected number of milliseconds before the actual data transmission or delay reception certain number of milli- seconds after the transmission is finished. In sc16is7xx, however, RTS signalling is handled by the hardware and driver has no way of providing this feature. We still try to provide .delay_rts_before_send by delaying transmission but without actual effect on the RTS line. Note: this change will make the driver return -EINVAL when the feature is requested (.delay_rts_after_send is set). Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01sc16is7xx: spi interface is addedRama Kiran Kumar Indrakanti3-10/+140
spi interface for sc16is7xx is added along with Kconfig flag to enable spi or i2c, thus in a instance we can have either spi or i2c or both, in sync to the hw. Signed-off-by: Rama Kiran Kumar Indrakanti <indrakanti_ram@hotmail.com> Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24drivers: PL011: add ACPI probing for SBSA UARTGraeme Gregory1-0/+8
Add the necessary driver boilerplate to let the driver be used when the respective ACPI table is discovered by the ACPI subsystem. [Andre: change table name, add MODULE_DEVICE_TABLE entry and improve commit message] Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24drivers: PL011: add support for the ARM SBSA generic UARTAndre Przywara1-0/+171
The ARM Server Base System Architecture[1] document describes a generic UART which is a subset of the PL011 UART. It lacks DMA support, baud rate control and modem status line control, among other things. The idea is to move the UART initialization and setup into the firmware (which does this job today already) and let the kernel just use the UART for sending and receiving characters. We use the recent refactoring to build a new struct uart_ops variable which points to some new functions avoiding access to the missing registers. We reuse as much existing PL011 code as possible. In contrast to the PL011 the SBSA UART does not define any AMBA or PrimeCell relations, so we go with a pretty generic probe function which only uses platform device functions. A DT binding is provided with this patch, ACPI support is added in a separate one. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24drivers: PL011: allow to supply fixed option stringAndre Przywara1-4/+13
The SBSA UART has a fixed baud rate and flow control setting, which cannot be changed or queried by software. Add a vendor specific property to always return fixed values when trying to read the console options. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24drivers: PL011: allow avoiding UART enabling/disablingAndre Przywara1-6/+12
The SBSA UART should not be enabled or disabled (it is always on), and consequently the spec lacks the UART_CR register. Add a vendor specific property to skip disabling or enabling of the UART. This will be used later by the SBSA UART support. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24drivers: PL011: move cts_event workaround into separate functionAndre Przywara1-13/+20
To avoid lines with more than 80 characters and to make the pl011_int() function more readable, move the workaround out into a separate function. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24drivers: PL011: replace UART_MIS reading with _RIS & _IMSCAndre Przywara1-2/+4
The PL011 register UART_MIS is actually a bitwise AND of the UART_RIS and the UART_MISC register. Since the SBSA UART does not include the _MIS register, use the two separate registers to get the same behaviour. Since we are inside the spinlock and we read the _IMSC register only once, there should be no race issue. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Naresh Bhat <nbhat@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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