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path: root/drivers/tty/serial/8250/8250_dw.c
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2022-08-30serial: Make ->set_termios() old ktermios constIlpo Järvinen
There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-08Merge tag 'tty-6.0-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial driver updates from Greg KH: "Here is the big set of tty and serial driver changes for 6.0-rc1. It was delayed from last week as I wanted to make sure the last commit here got some good testing in linux-next and elsewhere as it seemed to show up only late in testing for some reason. Nothing major here, just lots of cleanups from Jiri and Ilpo to make the tty core cleaner (Jiri) and the rs485 code simpler to use (Ilpo). Also included in here is the obligatory n_gsm updates from Daniel Starke and lots of tiny driver updates and minor fixes and tweaks for other smaller serial drivers. All of these have been in linux-next for a while with no reported problems" * tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (186 commits) tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements tty: amiserial: Fix comment typo tty: serial: document uart_get_console() tty: serial: serial_core, reformat kernel-doc for functions Documentation: serial: link uart_ops properly Documentation: serial: move GPIO kernel-doc to the functions Documentation: serial: dedup kernel-doc for uart functions Documentation: serial: move uart_ops documentation to the struct dt-bindings: serial: snps-dw-apb-uart: Document Rockchip RV1126 serial: mvebu-uart: uart2 error bits clearing tty: serial: fsl_lpuart: correct the count of break characters serial: stm32: make info structs static to avoid sparse warnings serial: fsl_lpuart: zero out parity bit in CS7 mode tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate. serial: 8250_bcm2835aux: Add missing clk_disable_unprepare() tty: vt: initialize unicode screen buffer serial: remove VR41XX serial driver serial: 8250: lpc18xx: Remove redundant sanity check for RS485 flags serial: 8250_dwlib: remove redundant sanity check for RS485 flags dt_bindings: rs485: Correct delay values ...
2022-07-14serial: 8250_dw: Avoid pslverr on reading empty receiver fifoVAMSHI GAJJELA
With PSLVERR_RESP_EN parameter set to 1, the device generates an error response when an attempt to read an empty RBR with FIFO enabled. This happens when LCR writes are ignored when UART is busy. dw8250_check_lcr() in retries to update LCR, invokes dw8250_force_idle() to clear and reset FIFO and eventually reads UART_RX causing the error. Avoid this by not reading RBR/UART_RX when no data is available. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: VAMSHI GAJJELA <vamshigajjela@google.com> Link: https://lore.kernel.org/r/20220713131722.2316829-1-vamshigajjela@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-30serial: 8250: dw: Fix the macro RZN1_UART_xDMACR_8_WORD_BURSTBiju Das
As per RZ/N1 peripheral user manual(r01uh0752ej0100-rzn1-peripheral.pdf) rev 1.0.0 Mar,2019, the value for 8_WORD_BURST is 4(b2,b1=2’b10). This patch fixes the macro as per the user manual. Fixes: aa63d786cea2 ("serial: 8250: dw: Add support for DMA flow controlling devices") Reviewed-by: Phil Edworthy <phil.edworthy@renesas.com> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> Link: https://lore.kernel.org/r/20220630083909.4294-1-biju.das.jz@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-30serial: 8250_dw: Use dw8250_serial_out() in dw8250_serial_out38x()Ilpo Järvinen
Place dw8250_serial_out() before dw8250_serial_out38x() so that it can be called from dw8250_serial_out38x() to do the actual write. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220628134234.53771-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-30serial: 8250_dw: Drop PM ifdefferyAndy Shevchenko
Drop CONFIG_PM and CONFIG_PM_SLEEP ifdeffery while converting dw8250_pm_ops to use new PM macros. Since we are using runtime PM, wrap dw8250_pm_ops into pm_ptr(). Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220630100507.31113-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-30serial: 8250_dw: Sort headers alphabeticallyAndy Shevchenko
For the sake of better maintenance, sort included headers alphabetically. While at it, split the serial group of headers which makes clear the subsystem the driver belongs to. Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220630093816.28271-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-30serial: 8250_dw: Take port lock while accessing LSRIlpo Järvinen
Accessing LSR requires port lock because it mutates lsr_saved_flags in serial_lsr_in(). Fixes: 197eb5c416ff ("serial: 8250_dw: Use serial_lsr_in() in dw8250_handle_irq()") Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/c5879db7-bee9-93f-526e-872a292442@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27serial: 8250: dw: enable using pdata with ACPIMarcin Wojtas
Commit ffd381445eac ("serial: 8250: dw: Move the USR register to pdata") caused NULL-pointer dereference when booting with ACPI by unconditional usage of the recently added pdata. In order to fix that and prevent similar issues in future, hook the default version of this structure in dw8250_acpi_match table. While at it, sort all entries alphabetically. Fixes: ffd381445eac ("serial: 8250: dw: Move the USR register to pdata") Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Marcin Wojtas <mw@semihalf.com> Link: https://lore.kernel.org/r/20220620121046.1307412-1-mw@semihalf.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27serial: 8250: create lsr_save_maskIlpo Järvinen
Allow drivers to alter LSR save mask. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220624204210.11112-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10serial: 8250_dw: Store LSR into lsr_saved_flags in dw8250_tx_wait_empty()Ilpo Järvinen
Make sure LSR flags are preserved in dw8250_tx_wait_empty(). This function is called from a low-level out function and therefore cannot call serial_lsr_in() as it would lead to infinite recursion. It is borderline if the flags need to be saved here at all since this code relates to writing LCR register which usually implies no important characters should be arriving. Fixes: 914eaf935ec7 ("serial: 8250_dw: Allow TX FIFO to drain before writing to UART_LCR") Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220608095431.18376-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10serial: 8250_dw: Use serial_lsr_in() in dw8250_handle_irq()Ilpo Järvinen
dw8250_handle_irq() reads LSR under a few conditions, convert both to use serial_lsr_in() in order to preserve LSR flags properly across reads. Fixes: 424d79183af0 ("serial: 8250_dw: Avoid "too much work" from bogus rx timeout interrupt") Fixes: aa63d786cea2 ("serial: 8250: dw: Add support for DMA flow controlling devices") Cc: Douglas Anderson <dianders@chromium.org> Cc: Phil Edworthy <phil.edworthy@renesas.com> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220608095431.18376-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-19serial: 8250_dw: Use dev_err_probe()Andy Shevchenko
Simplify the error path in ->probe() a bit by using dev_err_probe(). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220509172129.37770-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-19serial: 8250_dw: Use devm_add_action_or_reset()Andy Shevchenko
Slightly simplify ->probe() and drop a few goto labels by using devm_add_action_or_reset() for clock and reset cleanup. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220509172129.37770-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-19serial: 8250_dw: Update the list of OF headers used by driverAndy Shevchenko
The of_irq.h and of_platform.h are not used by the driver. On the other hand, the mod_devicetable.h missed. Drop the former two and add the latter one. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220509161911.37164-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: 8250: dw: Fix NULL pointer dereferenceHeikki Krogerus
dw8250_platform_data is only used on DT platforms for now. Fixes: 4a218b277fdb ("serial: 8250: dw: Create a generic platform data structure") Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220502115621.77985-1-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Improve RZN1 supportPhil Edworthy
Renesas RZ/N1 SoC features a slightly modified DW UART. On this SoC, the CPR register value is known but not synthetized in hardware. We hence need to provide a CPR value in the platform data. This version of the controller also relies on acting as flow controller when using DMA, so we need to provide the "is dma flow controller" quirk. Co-developed-by: Miquel Raynal <miquel.raynal@bootlin.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-10-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Add support for DMA flow controlling devicesPhil Edworthy
DW based controllers like the one on Renesas RZ/N1 must be programmed as flow controllers when using DMA. * Table 11.45 of the system manual, "Flow Control Combinations", states that using UART with DMA requires setting the DMA in the peripheral flow controller mode regardless of the direction. * Chapter 11.6.1.3 of the system manual, "Basic Interface Definitions", explains that the burst size in the above case must be configured in the peripheral's register DEST/SRC_BURST_SIZE. Experiments shown that upon Rx timeout, the DMA transaction needed to be manually cleared as well. Co-developed-by: Miquel Raynal <miquel.raynal@bootlin.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-9-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Introduce an rx_timeout variable in the IRQ pathMiquel Raynal
In a next change we are going to need the same Rx timeout condition as we already have in the IRQ handling code. Let's just create a boolean to clarify what this operation does before reusing it. There is no functional change. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-7-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Move the USR register to pdataMiquel Raynal
This offset is a good candidate to pdata's because it changes depending on the vendor implementation. Let's move the usr_reg entry from regular to pdata. This way we can drop initializing it at run time. Let's also use a define for it instead of defining only the default value. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-4-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Create a generic platform data structureEmil Renner Berthing
Use device tree match data rather than multiple calls to of_device_is_compatible() by introducing a platform data structure and adding a quirks mask. Provide a stub to the compatibles without quirks to simplify the handling of the upcoming changes. Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Emil Renner Berthing <kernel@esmil.dk> [<miquel.raynal@bootlin.com: Minor changes + creation of a real pdata structure] Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-3-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Move definitions to the shared headerPhil Edworthy
Move the per-device structure and a helper out of the main .c file, into a shared header as they will both be reused from another .c file. There is no functional change. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> [miquel.raynal@bootlin.com: Extracted from a bigger change] Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-2-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-16serial: 8250_dw: Add StarFive JH7100 quirkEmil Renner Berthing
On the StarFive JH7100 RISC-V SoC the UART core clocks can't be set to exactly 16 * 115200Hz and many other common bitrates. Trying this will only result in a higher input clock, but low enough that the UART's internal divisor can't come close enough to the baud rate target. So rather than try to set the input clock it's better to skip the clk_set_rate call and rely solely on the UART's internal divisor. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
2021-10-21serial: 8250_dw: drop bogus uartclk optimisationJohan Hovold
The driver was updating the port uartclk before setting the new rate in an attempt to avoid having the clock notifier redundantly update the divisors. The set_termios() callback is however called under the termios semaphore and tty-port mutex so the worker scheduled by the clock notifier will block in serial8250_update_uartclk() until the uartclk and divisors have been updated anyway. Drop the unnecessary swaps and incorrect comment and simply update the uartclk field if the clock-rate change was successful. Tested-by: Serge Semin <fancer.lancer@gmail.com> Reviewed-by: Serge Semin <fancer.lancer@gmail.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20211015111422.1027-4-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-10serial: 8250_lpss: Extract dw8250_do_set_termios() for common useAndy Shevchenko
Some of the code currently used in dw8250_set_termios(), byt_set_termios() may be reused by other methods in the future. Extract it to a common helper function. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211005133026.21488-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-10serial: 8250_dw: Fix the trivial typo in the commentAndy Shevchenko
Fix the trivial typo in the comment: Premilinary --> Preliminary. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211005134529.23256-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-10serial: 8250_dw: Re-use temporary variable for of_nodeAndy Shevchenko
In couple of places we may re-use temporary variable instead of dereferencing it. No functional changes intended. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211005134529.23256-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-10serial: 8250_dw: Drop wrong use of ACPI_PTR()Andy Shevchenko
ACPI_PTR() is more harmful than helpful. For example, in this case if CONFIG_ACPI=n, the ID table left unused which is not what we want. Instead of adding ifdeffery here and there, drop ACPI_PTR(). Fixes: 6a7320c4669f ("serial: 8250_dw: Add ACPI 5.0 support") Reported-by: Daniel Palmer <daniel@0x0f.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211005134516.23218-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13serial: 8250_dw: Add device HID for new AMD UART controllerMaximilian Luz
Add device HID AMDI0022 to the AMD UART controller driver match table and create a platform device for it. This controller can be found on Microsoft Surface Laptop 4 devices and seems similar enough that we can just copy the existing AMDI0020 entries. Cc: <stable@vger.kernel.org> # 5.10+ Tested-by: Sachi King <nakato@nakato.io> Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # for 8250_dw part Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com> Link: https://lore.kernel.org/r/20210512210413.1982933-1-luzmaximilian@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-30serial: 8250_dw: Fix clk-notifier/port suspend deadlockSerge Semin
It has been discovered that there is a potential deadlock between the clock-change-notifier thread and the UART port suspending one: CPU0 (suspend CPU/UART) CPU1 (update clock) ---- ---- lock(&port->mutex); lock((work_completion)(&data->clk_work)); lock(&port->mutex); lock((work_completion)(&data->clk_work)); *** DEADLOCK *** The best way to fix this is to eliminate the CPU0 port->mutex/work-completion scenario. So we suggest to register and unregister the clock-notifier during the DW APB UART port probe/remove procedures, instead of doing that at the points of the port startup/shutdown. Link: https://lore.kernel.org/linux-serial/f1cd5c75-9cda-6896-a4e2-42c5bfc3f5c3@redhat.com Fixes: cc816969d7b5 ("serial: 8250_dw: Fix common clocks usage race condition") Reported-by: Hans de Goede <hdegoede@redhat.com> Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20200923161950.6237-4-Sergey.Semin@baikalelectronics.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29serial: 8250_dw: Fix common clocks usage race conditionSerge Semin
The race condition may happen if the UART reference clock is shared with some other device (on Baikal-T1 SoC it's another DW UART port). In this case if that device changes the clock rate while serial console is using it the DW 8250 UART port might not only end up with an invalid uartclk value saved, but may also experience a distorted output data since baud-clock could have been changed. In order to fix this lets at least try to adjust the 8250 port setting like UART clock rate in case if the reference clock rate change is discovered. The driver will call the new method to update 8250 UART port clock rate settings. It's done by means of the clock event notifier registered at the port startup and unregistered in the shutdown callback method. Note 1. In order to avoid deadlocks we had to execute the UART port update method in a dedicated deferred work. This is due to (in my opinion redundant) the clock update implemented in the dw8250_set_termios() method. Note 2. Before the ref clock is manually changed by the custom set_termios() function we swap the port uartclk value with new rate adjusted to be suitable for the requested baud. It is necessary in order to effectively disable a functionality of the ref clock events handler for the current UART port, since uartclk update will be done a bit further in the generic serial8250_do_set_termios() function. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20200723003357.26897-5-Sergey.Semin@baikalelectronics.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29serial: 8250_dw: Pass the same rate to the clk round and set rate methodsSerge Semin
Indeed according to the clk API if clk_round_rate() has successfully accepted a rate, then in order setup the clock with value returned by the clk_round_rate() the clk_set_rate() method must be called with the original rate value. Suggested-by: Russell King <linux@armlinux.org.uk> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20200723003357.26897-4-Sergey.Semin@baikalelectronics.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29serial: 8250_dw: Simplify the ref clock rate setting procedureSerge Semin
Really instead of twice checking the clk_round_rate() return value we could do it once, and if it isn't error the clock rate can be changed. By doing so we decrease a number of ret-value tests and remove a weird goto-based construction implemented in the dw8250_set_termios() method. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20200723003357.26897-3-Sergey.Semin@baikalelectronics.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-04serial: 8250_dw: Avoid double error messaging when IRQ absentAndy Shevchenko
Since the commit 7723f4c5ecdb ("driver core: platform: Add an error message to platform_get_irq*()") platform_get_irq() started issuing an error message. Thus, there is no need to have the same in the driver Fixes: 7723f4c5ecdb ("driver core: platform: Add an error message to platform_get_irq*()") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191023103558.51862-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-04serial: 8250_dw: Use devm_clk_get_optional() to get the input clockAndy Shevchenko
Simplify the code which fetches the input clock by using devm_clk_get_optional(). This comes with a small functional change: previously all errors were ignored except deferred probe. Now all errors are treated as errors. If no input clock is present devm_clk_get_optional() will return NULL instead of an error which matches the behavior of the old code. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20190925162617.30368-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04serial: 8250_dw: switch to use 8250_dwlib libraryAndy Shevchenko
Since we have a common library module for Synopsys DesignWare UART, let us use it. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20190806094322.64987-4-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04serial: 8250_dw: use pointer to uart local variableAndy Shevchenko
The use of pointer will simplify enabling runtime PM for the driver. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20190806094322.64987-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04serial: 8250_dw: Use a unified new dev variable in removeAndy Shevchenko
The commit 2cb78eab2376 ("serial: 8250_dw: Use a unified new dev variable in probe") introduced a local dev variable in ->probe(). Do the same in ->remove() in order to prepare for sequential patches. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Link: https://lore.kernel.org/r/20190806094322.64987-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-21dmaengine: idma64: Use actual device for DMA transfersAndy Shevchenko
Intel IOMMU, when enabled, tries to find the domain of the device, assuming it's a PCI one, during DMA operations, such as mapping or unmapping. Since we are splitting the actual PCI device to couple of children via MFD framework (see drivers/mfd/intel-lpss.c for details), the DMA device appears to be a platform one, and thus not an actual one that performs DMA. In a such situation IOMMU can't find or allocate a proper domain for its operations. As a result, all DMA operations are failed. In order to fix this, supply parent of the platform device to the DMA engine framework and fix filter functions accordingly. We may rely on the fact that parent is a real PCI device, because no other configuration is present in the wild. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [for tty parts] Signed-off-by: Vinod Koul <vkoul@kernel.org>
2018-10-02Revert "serial: 8250_dw: Fix runtime PM handling"Guenter Roeck
This reverts commit d76c74387e1c978b6c5524a146ab0f3f72206f98. While commit d76c74387e1c ("serial: 8250_dw: Fix runtime PM handling") fixes runtime PM handling when using kgdb, it introduces a traceback for everyone else. BUG: sleeping function called from invalid context at /mnt/host/source/src/third_party/kernel/next/drivers/base/power/runtime.c:1034 in_atomic(): 1, irqs_disabled(): 1, pid: 1, name: swapper/0 7 locks held by swapper/0/1: #0: 000000005ec5bc72 (&dev->mutex){....}, at: __driver_attach+0xb5/0x12b #1: 000000005d5fa9e5 (&dev->mutex){....}, at: __device_attach+0x3e/0x15b #2: 0000000047e93286 (serial_mutex){+.+.}, at: serial8250_register_8250_port+0x51/0x8bb #3: 000000003b328f07 (port_mutex){+.+.}, at: uart_add_one_port+0xab/0x8b0 #4: 00000000fa313d4d (&port->mutex){+.+.}, at: uart_add_one_port+0xcc/0x8b0 #5: 00000000090983ca (console_lock){+.+.}, at: vprintk_emit+0xdb/0x217 #6: 00000000c743e583 (console_owner){-...}, at: console_unlock+0x211/0x60f irq event stamp: 735222 __down_trylock_console_sem+0x4a/0x84 console_unlock+0x338/0x60f __do_softirq+0x4a4/0x50d irq_exit+0x64/0xe2 CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc5 #6 Hardware name: Google Caroline/Caroline, BIOS Google_Caroline.7820.286.0 03/15/2017 Call Trace: dump_stack+0x7d/0xbd ___might_sleep+0x238/0x259 __pm_runtime_resume+0x4e/0xa4 ? serial8250_rpm_get+0x2e/0x44 serial8250_console_write+0x44/0x301 ? lock_acquire+0x1b8/0x1fa console_unlock+0x577/0x60f vprintk_emit+0x1f0/0x217 printk+0x52/0x6e register_console+0x43b/0x524 uart_add_one_port+0x672/0x8b0 ? set_io_from_upio+0x150/0x162 serial8250_register_8250_port+0x825/0x8bb dw8250_probe+0x80c/0x8b0 ? dw8250_serial_inq+0x8e/0x8e ? dw8250_check_lcr+0x108/0x108 ? dw8250_runtime_resume+0x5b/0x5b ? dw8250_serial_outq+0xa1/0xa1 ? dw8250_remove+0x115/0x115 platform_drv_probe+0x76/0xc5 really_probe+0x1f1/0x3ee ? driver_allows_async_probing+0x5d/0x5d driver_probe_device+0xd6/0x112 ? driver_allows_async_probing+0x5d/0x5d bus_for_each_drv+0xbe/0xe5 __device_attach+0xdd/0x15b bus_probe_device+0x5a/0x10b device_add+0x501/0x894 ? _raw_write_unlock+0x27/0x3a platform_device_add+0x224/0x2b7 mfd_add_device+0x718/0x75b ? __kmalloc+0x144/0x16a ? mfd_add_devices+0x38/0xdb mfd_add_devices+0x9b/0xdb intel_lpss_probe+0x7d4/0x8ee intel_lpss_pci_probe+0xac/0xd4 pci_device_probe+0x101/0x18e ... Revert the offending patch until a more comprehensive solution is available. Cc: Tony Lindgren <tony@atomide.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Phil Edworthy <phil.edworthy@renesas.com> Fixes: d76c74387e1c ("serial: 8250_dw: Fix runtime PM handling") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-02serial: 8250_dw: Add ACPI support for uart on Broadcom SoCSrinath Mannam
Add ACPI identifier HID for UART DW 8250 on Broadcom SoCs to match the HID passed through ACPI tables to enable UART controller. Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com> Reviewed-by: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com> Tested-by: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com> Reviewed-by: Ray Jui <ray.jui@broadcom.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-02serial: 8250_dw: always set baud rate in dw8250_set_termiosChen Hu
dw8250_set_termios() doesn't set baud rate if the arg "old ktermios" is NULL. This happens during resume. Call Trace: ... [ 54.928108] dw8250_set_termios+0x162/0x170 [ 54.928114] serial8250_set_termios+0x17/0x20 [ 54.928117] uart_change_speed+0x64/0x160 [ 54.928119] uart_resume_port ... So the baud rate is not restored after S3 and breaks the apps who use UART, for example, console and bluetooth etc. We address this issue by setting the baud rate irrespective of arg "old", just like the drivers for other 8250 IPs. This is tested with Intel Broxton platform. Signed-off-by: Chen Hu <hu1.chen@intel.com> Fixes: 4e26b134bd17 ("serial: 8250_dw: clock rate handling for all ACPI platforms") Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: stable <stable@vger.kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-21serial: 8250_dw: Add compatible string for Renesas RZ/N1 UARTPhil Edworthy
The Renesas RZ/N1 UART is based on the Synopsys DW UART, but has additional registers for DMA. This patch does not address the changes required for DMA support, it simply adds the compatible string. Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-12serial: 8250_dw: add fractional divisor supportJisheng Zhang
For Synopsys DesignWare 8250 uart which version >= 4.00a, there's a valid divisor latch fraction register. The fractional divisor width is 4bits ~ 6bits. Now the preparation is done, it's easy to add the feature support. This patch firstly tries to get the fractional divisor width during probe, then setups dw specific get_divisor() and set_divisor() hook. Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-07serial: 8250_dw: Introduce IO accessors to extended registersAndy Shevchenko
There are several extended (in comparison to the traditional 16550) registers are present in Synopsys DesignWare UART. All of them are 32-bit ones. Introduce helpers to simplify access to them and convert existing users. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14serial: 8250_dw: Fix runtime PM handlingPhil Edworthy
When using kgdb, you get an abort when accessing the UART registers. This is because the driver has already entered runtime PM and so turned off the bus clock needed to access the registers. To fix this, set the capability indicating Runtime PM is active while idle. Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23serial: 8250_dw: Limit dw8250_tx_wait_empty quirk to armada-38x devicesJoshua Scott
The previous implementation has had a detrimental effect on devices using high bitrates (bluetooth), as the fifo being non-empty for a single check would result in a 10 µs delay. Limit the change to devices with the new "marvell,armada-38x-uart" compatible string. Also update the code to allow the first 1000 retries to not perform a delay. The maximum duration of retries has been increased to cover a worst-case seen on the Armada 385 SoC. "dmesg ; resize", will fill the buffer with text to output before doing a resize. At 9600 baud this took up to 13 ms to flush all characters and avoid some getting lost. Signed-off-by: Joshua Scott <joshua.scott@alliedtelesis.co.nz> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: 8250_dw: Switch to use acpi_dev_present()Andy Shevchenko
Special settings for APMC0D08 are applied when device is present in the system. To check its presence we may use acpi_dev_present() instead of current open coded variant. Cc: Feng Kan <fkan@apm.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: 8250_dw: Allow TX FIFO to drain before writing to UART_LCRJoshua Scott
An issue has been observed on the Marvell Armada 38x serial port. Writes to UART_LCR can result in characters that are currently held in the TX FIFO being lost rather than sent, even if the userspace process has attempted to flush them. This is most visible when using the "resize" command (tested on Busybox), where we have observed the escape code for restoring cursor position becoming mangled. Signed-off-by: Joshua Scott <joshua.scott@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-22serial: 8250_dw: Revert "Improve clock rate setting"Andy Shevchenko
The commit de9e33bdfa22 ("serial: 8250_dw: Improve clock rate setting") obviously tries to cure symptoms, and not a root cause. The root cause is the non-flexible rate calculation inside the corresponding clock driver. What we need is to provide maximum UART divisor value to the clock driver to allow it do the job transparently to the caller. Since from the initial commit message I have got no clue which clock driver actually needs to be amended, I leave this exercise to the people who know better the case. Moreover, it seems [1] the fix introduced a regression. And possible even one more [2]. Taking above, revert the commit de9e33bdfa22 for now. [1]: https://www.spinics.net/lists/linux-serial/msg28872.html [2]: https://github.com/Dunedan/mbp-2016-linux/issues/29#issuecomment-357583782 Fixes: de9e33bdfa22 ("serial: 8250_dw: Improve clock rate setting") Cc: stable <stable@vger.kernel.org> # 4.15 Cc: Ed Blake <ed.blake@sondrel.com> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: Lukas Wunner <lukas@wunner.de> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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