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path: root/drivers/tty/serial/atmel_serial.c
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2016-06-26tty/serial: atmel: enforce tasklet init and termination sequencesNicolas Ferre1-23/+38
As some race conditions are identified in the termination process of tasklets, enforce the atmel_shutdown() sequence. This way we make sure that no new tasklets or software timer are scheduled during shutdown process. An atomic flag is positioned to give this information throughout the code. We also remove tasklet_disable() calls that were leading to deadlocks while stopping the driver. A simpler init/kill sequence is used. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25tty/serial: atmel: fix RS485 half duplex with DMAAlexandre Belloni1-6/+8
When using DMA, half duplex doesn't work properly because rx is not stopped before starting tx. Ensure we call atmel_stop_rx() in the DMA case. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25tty/serial: atmel: add comment for the ring buffer size macroLudovic Desroches1-0/+6
There is a macro named ATMEL_SERIAL_RINGSIZE which suggesting that it corresponds to the real size of the ring buffer. Let warn people that there is a factor of four since allocation size is sizeof(struct atmel_uart_char) * ATMEL_SERIAL_RINGSIZE. Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25tty/serial: atmel: split tx and rx pathsNicolas Ferre1-19/+34
Split TX and RX paths to not schedule RX tasklet on TX events and vice versa. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25tty/serial: atmel: re-integrate status check in irq handlerNicolas Ferre1-26/+17
The IRQ status check and related actions was done in the tasklet without benefit. So, move it back to the IRQ context to simplify IRQ handling and having the possibility to split the tasklet in two separated ones for receive and transmit actions. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-29tty/serial: atmel: fix hardware handshake selectionAlexandre Belloni1-1/+13
Commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled") actually allowed to enable hardware handshaking. Before, the CRTSCTS flags was silently ignored. As the DMA controller can't drive RTS (as explain in the commit message). Ensure that hardware flow control stays disabled when DMA is used and FIFOs are not available. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Fixes: 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled") Cc: stable <stable@vger.kernel.org> # v4.0+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-08tty/serial: at91: fix bad offset for UART timeout registerLudovic Desroches1-6/+13
With SAMA5D2, the UART has hw timeout but the offset of the register to define this value is not the same as the one for USART. When using the new UART, the value of this register was 0 so we never get timeout irqs. It involves that when using DMA, we were stuck until the execution of the dma callback which happens when a buffer is full (so after receiving 2048 bytes). Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-08tty/serial: at91: restore dynamic driver bindingRomain Izard1-1/+34
In commit c39dfebc7798956fd2140ae6321786ff35da30c3, the modular support code for atmel_serial was removed, as the driver cannot be built as a module. Because no use case was proposed, the dynamic driver binding support was removed as well. The atmel_serial driver can manage up to 7 serial controllers, which are multiplexed with other functions. For example, in the Atmel SAMA5D2, the Flexcom controllers can work as USART, SPI or I2C controllers, and on all Atmel devices serial lines can be reconfigured as GPIOs. My use case uses GPIOs to transfer a firmware update using a custom protocol on the lines used as a serial port during the normal life of the device. If it is not possible to unbind the atmel_serial driver, the GPIO lines remain reserved and prevent this case from working. This patch reinstates the atmel_serial_remove function, and fixes it as it failed to clear the "clk" field on removal, triggering an oops when a device was bound again after being unbound. Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Romain Izard <romain.izard.pro@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07serial: atmel: Use atmel_port consistentlyJaeden Amero1-47/+48
In all functions other than atmel_serial_probe_fifos, atmel_serial_probe, and atmel_console_init, the name "port" is used to refer to an instance of struct uart_port. In many of these functions, "atmel_port" is used to refer to an instance of struct atmel_uart_port. We make the use of the name "port" consistent by making atmel_serial_probe_fifos, atmel_serial_probe, and atmel_console_init use "atmel_port" to refer to an instance of struct atmel_uart_port instead of the previous name of "port". Signed-off-by: Jaeden Amero <jaeden.amero@ni.com> Signed-off-by: Kyle Roeschley <kyle.roeschley@ni.com> Acked-by: Karthik Manamcheri <karthik.manamcheri@ni.com> [nicolas.ferre@atmel.com: fix typo in variable, adapt to newer kernel] Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07serial: atmel: add support for new UART versionNicolas Ferre1-3/+4
Starting with sama5d2, the new UART revision has an hardware timer. So, add it to the IP detection code and set the "has_hw_timer" property for it. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Reported-by: David Mosberger <davidm@egauge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07serial: atmel: trivial: clean the IP version decoding codeNicolas Ferre1-16/+16
No functional change is associated with this patch. A driver property depends on the Atmel serial IP revision. This property is the way the rx timeout is handled: by an hardware or software timer. So, change this property name and setup code so that it's easier to understand and more future proof as the distinction of USART vs. UART is blurrier on newer SoCs. Variable names and debug comments are also adapted to make this code more obvious. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-09drivers/tty/serial: delete unused MODULE_DEVICE_TABLE from atmel_serial.cPaul Gortmaker1-2/+0
In commit c39dfebc7798956fd2140ae6321786ff35da30c3 ("drivers/tty/serial: make serial/atmel_serial.c explicitly non-modular") we removed the code relating to modular support since it currently only supports built in. However, when redoing my build coverage for mips allmodconfig, which sets CONFIG_OF, I noticed a remaining line that needs to be removed, else we will get a build failure for an undefined module macro. Unfortunately this didn't appear for any of the other arch I tested more frequently, such as ARM. Since MODULE_DEVICE_TABLE is a no-op for non-modular code, we can just remove the offending line. Fixes: c39dfebc7798 ("drivers/tty/serial: make serial/atmel_serial.c explicitly non-modular") Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Jiri Slaby <jslaby@suse.com> Reported-by: Sudip Mukherjee <sudip@vectorindia.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Acked-by: Sudip Mukherjee <sudip@vectorindia.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14drivers/tty/serial: make serial/atmel_serial.c explicitly non-modularPaul Gortmaker1-41/+4
The Kconfig currently controlling compilation of this code is: drivers/tty/serial/Kconfig:config SERIAL_ATMEL drivers/tty/serial/Kconfig: bool "AT91 / AT32 on-chip serial port support" ...meaning that it currently is not being built as a module by anyone. Lets remove the modular code that is essentially orphaned, so that when reading the driver there is no doubt it is builtin-only. We explicitly disallow a driver unbind, since that doesn't have a sensible use case anyway, and it allows us to drop the ".remove" code for non-modular drivers. Since module_init translates to device_initcall in the non-modular case, the init ordering remains unchanged with this commit. We don't replace module.h with init.h since the file already has that. We also delete the MODULE_LICENSE tag etc. since all that information is already contained at the top of the file in the comments. Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-serial@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14serial: atmel: convert to irq handling provided mctrl-gpioUwe Kleine-König1-122/+18
Tested-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-18serial: at91, fix rs485 propertiesJiri Slaby1-3/+2
There is a misplaced bracket in atmel_init_rs485 which sets rs485-rx-during-tx and rs485-enabled-at-boot-time only if rs485-rts-delay is set in of. This is clearly a bug, so fix it by moving the bracket to the proper place. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Elen Song <elen.song@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-18serial: atmel: fix compiler warning on address castAndre Przywara1-1/+1
Turning on KVM and LPAE support on top of a multi_v7_defconfig will produce a compiler warning in the Atmel serial driver: drivers/tty/serial/atmel_serial.c: In function 'atmel_verify_port': drivers/tty/serial/atmel_serial.c:2299:6: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] if ((void *)port->mapbase != ser->iomem_base) ^ Fix that by using the cast on the right hand side instead, as similar code already does in other drivers. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-12Merge 4.3-rc5 into tty-nextGreg Kroah-Hartman1-1/+1
We want the tty fixes and reverts in here as well so that people can properly test and use it. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: atmel: fix error path of probe functionUwe Kleine-König1-1/+1
If atmel_init_gpios fails the port has already been marked as busy (in line 2629), so this must be undone in the error path. This bug was introduced because I created the patch that finally became 722ccf416ac2 ("serial: atmel: fix error handling when mctrl_gpio_init fails") on top of 3.19 which didn't have commit 6fbb9bdf0f3f ("tty/serial: at91: fix error handling in atmel_serial_probe()") yet. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Fixes: 722ccf416ac2 ("serial: atmel: fix error handling when mctrl_gpio_init fails") Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: mctrl-gpio: rename init functionUwe Kleine-König1-1/+1
This is done before adding more functionality to the init function with the existing name. As this new functionality conflicts with stuff drivers are required to implement themselves up to I want to convert them one by one to make reviewing and reverting more easy in case I broke something. Once mctrl_gpio_init is there and all drivers are converted mctrl_gpio_init_noauto can be removed again. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04serial: atmel: allow compile testing on non-atmel architecturesUwe Kleine-König1-6/+6
This commit also fixes compiler warnings and errors seen when building on x86_64. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04tty/serial: at91: move ATMEL_MAX_UARTAlexandre Belloni1-0/+6
Move ATMEL_MAX_UART from platform_data/atmel.h to atmel_serial.c as this is the only file using it and it is common practise from tty/serial drivers to define it directly in the driver file. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05tty/serial: at91: fix I/O accesses on RHR and THR for AVR32Cyrille Pitchen1-10/+27
This patch fixes I/O accesses on the Receiver Holding Register and on the Transmitter Holding Register. Indeed AVR32 can only perform 32bit I/O accesses on registers: using 8bit I/O accesses would read or write garbage data. Fixes: commit b5199d468177 ("tty/serial: at91: add support to FIFOs") Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-24tty/serial: at91: use 32bit writes into TX FIFO when DMA is enabledCyrille Pitchen1-15/+51
For now this improvement is only used with TX DMA transfers. The data width must be set properly when configuring the DMA controller. Also the FIFO configuration must be set to match the DMA transfer data width: TXRDYM (Transmitter Ready Mode) and RXRDYM (Receiver Ready Mode) must be set into the FIFO Mode Register. These values are used by the USART to trigger the DMA controller. In single data mode they are not used and should be reset to 0. So the TXRDYM bits are changed to FOUR_DATA; then USART triggers the DMA controller when at least 4 data can be written into the TX FIFO througth the THR. On the other hand the RXRDYM bits are left unchanged to ONE_DATA. Atmel eXtended DMA controller allows us to set a different data width for each part of a scatter-gather transfer. So when calling dmaengine_slave_config() to configure the TX path, we just need to set dst_addr_width to the maximum data width. Then DMA writes into THR are split into up to two parts. The first part carries the first data to be sent and has a length equal to the greatest multiple of 4 (bytes) lower than or equal to the total length of the TX DMA transfer. The second part carries the trailing data (up to 3 bytes). The first part is written by the DMA into THR using 32 bit accesses, whereas 8bit accesses are used for the second part. Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-24tty/serial: at91: add support to FIFOsCyrille Pitchen1-6/+94
Depending on the hardware, TX and RX FIFOs may be available. The RX FIFO can avoid receive overruns, especially when DMA transfers are not used to read data from the Receive Holding Register. For heavy system load, The CPU is likely not be able to fetch data fast enough from the RHR. In addition, the RX FIFO can supersede the DMA/PDC to control the RTS line when the Hardware Handshaking mode is enabled. Two thresholds are to be set for that purpose: - When the number of data in the RX FIFO crosses and becomes lower than or equal to the low threshold, the RTS line is set to low level: the remote peer is requested to send data. - When the number of data in the RX FIFO crosses and becomes greater than or equal to the high threshold, the RTS line is set to high level: the remote peer should stop sending new data. - low threshold <= high threshold Once these two thresholds are set properly, this new feature is enabled by setting the FIFO RTS Control bit of the FIFO Mode Register. FIFOs also introduce a new multiple data mode: the USART works either in multiple data mode or in single data (legacy) mode. If MODE9 bit is set into the Mode Register or if USMODE is set to either LIN_MASTER, LIN_SLAVE or LON_MODE, FIFOs operate in single data mode. Otherwise, they operate in multiple data mode. In this new multiple data mode, accesses to the Receive Holding Register or Transmit Holding Register slightly change. Since this driver implements neither the 9bit data feature (MODE9 bit set into the Mode Register) nor LIN modes, the USART works in multiple data mode whenever FIFOs are available and enabled. We also assume that data are 8bit wide. In single data mode, 32bit access CAN be used to read a single data from RHR or write a single data into THR. However in multiple data mode, a 32bit access to RHR now allows us to read four consecutive data from RX FIFO. Also a 32bit access to THR now allows to write four consecutive data into TX FIFO. So we MUST use 8bit access whenever only one data have to be read/written at a time. Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-24tty/serial: at91: remove bunch of macros to access UART registersCyrille Pitchen1-154/+159
This patch replaces the UART_PUT_*, resp. UART_GET_*, macros by atmel_uart_writel(), resp. atmel_uart_readl(), inline function calls. Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24tty/serial: at91: RS485 mode: 0 is valid for delay_rts_after_sendNicolas Ferre1-6/+3
In RS485 mode, we may want to set the delay_rts_after_send value to 0. In the datasheet, the 0 value is said to "disable" the Transmitter Timeguard but this is exactly the expected behavior if we want no delay... Moreover, if the value was set to non-zero value by device-tree or earlier ioctl command, it was impossible to change it back to zero. Reported-by: Sami Pietikäinen <Sami.Pietikainen@wapice.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: stable@vger.kernel.org # 3.2+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06tty/serial: at91: handle IRQ status more safelyLeilei Zhao1-6/+7
Handle the changed flag of IRQ status in interruption instead of handling it in tasklet due to the tasklet may be scheduled more than once in one interruption. Otherwise, the changed status may be processed more than once which will lead to unexpected result. And seriously, kernel will crash. Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-28tty/serial: at91: maxburst was missing for dma transfersLudovic Desroches1-0/+2
Maxburst was not set when doing the dma slave configuration. This value is checked by the recently introduced xdmac. It causes an error when doing the slave configuration and so prevents from using dma. Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Cc: <stable@vger.kernel.org> # 3.12 and later Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-09Merge 4.0-rc3 into tty-testingGreg Kroah-Hartman1-12/+17
This resolves a merge issue in drivers/tty/serial/8250/8250_pci.c Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07tty/serial: at91: correct the usage of taskletLeilei Zhao1-0/+4
The tasklet may be scheduled and executed after serial port was shutdown, for example, DMA rx callback will schedule the tasklet while serial port is shutting down, especially serial port is sending and receiving data in a higher baud rate and it's killed by external program. In this case, tasklet_kill can only clear the current scheduling out, so tasklet should be disabled to prevent being executed in later scheduling. Otherwise, the tasklet executed after serial port was shutdown can lead to kernel crash. Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07tty/serial: at91: set ops in property init each timeLeilei Zhao1-0/+1
The property in device tree will be reading each time when tty is opened, so the ops of serial port should be set after that instead of setting once in probe. Otherwise, the ops of serial port is inconsistent with the state of serial work manner. For example, the atmel serial driver can't work when switching to PIO mode due to DMA channel is not available. Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07tty/serial: at91: revise the return type of atmel_init_propertyLeilei Zhao1-4/+3
The function of atmel_init_property is to set the work manner of atmel serial ports according to the property in device trees. If DMA or PDC is not set or something goes wrong in getting property, the work manner will switch to general PIO mode, thus there will not be any failure case in this function. It's actually a procedure. So changing the return type from int to void. Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07tty/serial: at91: correct buffer size used in DMALeilei Zhao1-1/+1
The buffer size set in DMA is inconsistent with its allocation. So keep them consistent here. The structure atmel_uart_char is used in PIO mode with its meaning. But here in DMA, all of the buffer is treated as general char. Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07tty/serial: at91: correct check of buf used in DMALeilei Zhao1-2/+2
We only use buf of ring In DMA rx function while using buf of xmit in DMA tx function. So in DMA rx we need definitively to check the buf of ring which is corresponding to DMA rx function. And use macro PAGE_ALIGNED to simplify the expression. Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07serial: atmel: fix error handling when mctrl_gpio_init failsUwe Kleine-König1-5/+6
mctrl_gpio_init at present doesn't return NULL. (It might be used in the future when no gpios are to be used indicating success.) Properly pass error returned and also make driver probing fail on error. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-06tty: serial: atmel: rework interrupt and wakeup handlingBoris BREZILLON1-4/+45
The IRQ line connected to the DBGU UART is often shared with a timer device which request the IRQ with IRQF_NO_SUSPEND. Since the UART driver is correctly disabling IRQs when entering suspend we can safely request the IRQ with IRQF_COND_SUSPEND so that irq core will not complain about mixing IRQF_NO_SUSPEND and !IRQF_NO_SUSPEND. Rework the interrupt handler to wake the system up when an interrupt happens on the DEBUG_UART while the system is suspended. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-10tty/serial: at91: fix typo and indentationCyrille Pitchen1-18/+22
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-10tty/serial: at91: fix RTS line management when hardware handshake is enabledCyrille Pitchen1-30/+61
This patch fixes many bugs in the code dealing with the hardware handshake. As an example, in atmel_set_termios(), we used to test whether the CRTSCTS c_cflag was set. If so, we selected the "Hardware Handshake" mode through the Mode Register. However, few lines below the mode was reset to "Normal" (0). So there was no way to select the "Hardware Handshake" mode. To fix this issue, we moved the CRTSCRTS c_cflag test AFTER the mode has been reset to "Normal". Also setting the RTSEN and RTSDIS bits in the Control Register has different results whether the USART is set in "Normal" or "Hardware Handshake" mode: 1) "Normal" mode - the RTSEN bit forces the RTS line to low level, which tells the remote peer that we are ready to received new data. - the RTSDIS bit forces the RTS line to high level, which tells the remote peer to stop sending new data. 2) "Hardware Handshake" mode - the RTSEN bit forces the RTS line to high level. - the RTSDIS bit lets the hardware control the RTS line. WARNING: when FIFOs are not available or not enabled, the RTS line is controlled by the PDC. This is why using the Hardware Handshake mode requires using the PDC channel for reception. However the Hardware Handshake mode DOES NOT work with DMA controller since it cannot control the RTS line. Future designs with FIFOs will introduce a new feature: the RTS line will be controlled by the RX FIFO using thresholds. This patch was tested with this new design. Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-10tty/serial: at91: fix error handling in atmel_serial_probe()Cyrille Pitchen1-1/+3
-EDEFER error wasn't handle properly by atmel_serial_probe(). As an example, when atmel_serial_probe() is called for the first time, we pass the test_and_set_bit() test to check whether the port has already been initalized. Then we call atmel_init_port(), which may return -EDEFER, possibly returned before by clk_get(). Consequently atmel_serial_probe() used to return this error code WITHOUT clearing the port bit in the "atmel_ports_in_use" mask. When atmel_serial_probe() was called for the second time, it used to fail on the test_and_set_bit() function then returning -EBUSY. When atmel_serial_probe() fails, this patch make it clear the port bit in the "atmel_ports_in_use" mask, if needed, before returning the error code. Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: <stable@vger.kernel.org> # 3.12+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-10tty/serial: at91: enable peripheral clock before accessing I/O registersCyrille Pitchen1-0/+12
atmel_serial_probe() calls atmel_init_port(). In turn, atmel_init_port() calls clk_disable_unprepare() to disable the peripheral clock before returning. Later atmel_serial_probe() accesses some I/O registers such as the Mode and Control registers for RS485 support then the Name and Version registers, through a call to atmel_get_ip_name(), but at that moment the peripheral clock was still disabled. Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: <stable@vger.kernel.org> # 3.12+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-10tty/serial: at91: use correct type for dma_sync_*_for_cpu() and ↵Cyrille Pitchen1-3/+3
dma_sync_*_for_device() dma_sync_*_for_cpu() and dma_sync_*_for_device() use 'enum dma_data_direction', not 'enum dma_transfer_direction' Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-12-15Merge tag 'driver-core-3.19-rc1' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core update from Greg KH: "Here's the set of driver core patches for 3.19-rc1. They are dominated by the removal of the .owner field in platform drivers. They touch a lot of files, but they are "simple" changes, just removing a line in a structure. Other than that, a few minor driver core and debugfs changes. There are some ath9k patches coming in through this tree that have been acked by the wireless maintainers as they relied on the debugfs changes. Everything has been in linux-next for a while" * tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits) Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries" fs: debugfs: add forward declaration for struct device type firmware class: Deletion of an unnecessary check before the function call "vunmap" firmware loader: fix hung task warning dump devcoredump: provide a one-way disable function device: Add dev_<level>_once variants ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries ath: use seq_file api for ath9k debugfs files debugfs: add helper function to create device related seq_file drivers/base: cacheinfo: remove noisy error boot message Revert "core: platform: add warning if driver has no owner" drivers: base: support cpu cache information interface to userspace via sysfs drivers: base: add cpu_device_create to support per-cpu devices topology: replace custom attribute macros with standard DEVICE_ATTR* cpumask: factor out show_cpumap into separate helper function driver core: Fix unbalanced device reference in drivers_probe driver core: fix race with userland in device_add() sysfs/kernfs: make read requests on pre-alloc files use the buffer. sysfs/kernfs: allow attributes to request write buffer be pre-allocated. fs: sysfs: return EGBIG on write if offset is larger than file size ...
2014-11-07tty/serial_core: Introduce lock mechanism for RS485Ricardo Ribalda Delgado1-6/+4
Introduce an homogeneous lock system between setting and using the rs485 data of the uart_port. This patch should not be split into multiple ones in order to avoid leaving the tree in an unstable state. Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Suggested-by: Alan Cox <alan@linux.intel.com> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07serial/atmel: Use the rs485 functions on serial_coreRicardo Ribalda Delgado1-55/+24
In order to unify all the rs485 ioctl handling. Use the implementation of TIOC[GS]RS485 ioctl handling on serial_core. Reviewed-by: Alan Cox <alan@linux.intel.com> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07serial: Test/disable MSIs if switching from N_PPSPeter Hurley1-0/+5
Switching to the N_PPS line discipline may require enabling modem status interrupts; conversely switching from N_PPS may require disabling modem status interrupts. Affected drivers: 8250 amba-pl010 atmel Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07serial: Take uart port lock for direct *_enable_ms()Peter Hurley1-0/+2
Three UART drivers (8250, atmel & amba-pl010) directly call their enable_ms() method; the uart port lock must be acquired before any h/w programming. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07serial: core: Pass termios to set_ldisc() notificationsPeter Hurley1-2/+2
UART drivers which enable modem status interrupts when switching to N_PPS line discipline need to determine if modem status interrupts should be disabled when switching from N_PPS. Specifically, the set_ldisc() notification needs to evaluate UART_ENABLE_MS() which requires termios->c_cflag. Convert in-tree UART drivers to new interface. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07serial: at91: Use dmaengine_slave_config APIMaxime Ripard1-6/+4
We are removing the dmaengine_device_control API, that shouldn't even have been exposed in the first place. Change the callers to use the proper API. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07tty/serial: at91: fix rx ring buffer managementCyrille Pitchen1-39/+55
This patch swaps the use "tail" and "head" to fit the semantic of the linux circular buffer documentation: - head: the point at which the producer (the DMA controller) inserts items. - tail: the point at which the consumer (the serial framework) finds the next item. Besides the former code of the rx ring buffer didn't manage the case where head < tail, which might lead to loss of data. To fix this bug the data are now sent from the DMA buffer to the serial framework in two steps: 1 - First, we test if head < tail. If so, we copy the data from tail to the end of the DMA buffer then reset tail to zero. 2 - Finally, we copy data from tail to head then set tail to head. In addition, since tty_insert_flip_string() may now be called twice, atmel_flip_buffer_rx_dma() becomes less efficient than moving the calls dma_sync_sg_for_cpu(), dma_sync_sg_for_device(), tty_insert_flip_string() and tty_flip_buffer_push() directly into atmel_rx_from_dma(). Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06serial: Refactor uart_flush_buffer() from uart_close()Peter Hurley1-13/+15
In the context of the final tty & port close, flushing the tx ring buffer after the hardware has already been shutdown and the ring buffer freed is neither required nor desirable. uart_flush_buffer() performs 3 operations: 1. Resets tx ring buffer indices, but the tx ring buffer has already been freed and the indices are reset if the port is re-opened. 2. Calls uart driver's flush_buffer() method 5 in-tree uart drivers define flush_buffer() methods: amba-pl011, atmel-serial, imx, serial-tegra, timbuart These have been refactored into the shutdown() method, if required. 3. Kicks the ldisc for more writing, but this is undesirable. The file handle is being released; any waiting writer will will be kicked out by tty_release() with a warning. Further, the N_TTY ldisc may generate SIGIO for a file handle which is no longer valid. Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>