summaryrefslogtreecommitdiff
path: root/drivers/tty
AgeCommit message (Collapse)Author
2022-05-05serial: pic32: don't assign pic32_sport::cts_gpio twiceJiri Slaby
sport->cts_gpio is first assigned -EINVAL and few lines below using of_get_named_gpio(). Remove the first (useless) assignment. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220503063122.20957-9-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: pic32: convert to_pic32_sport() to an inlineJiri Slaby
'c' is not in wrapped in parentheses in the to_pic32_sport() macro, so it might be problematic wrt macro expansion. Using an inline is always safer in these cases. Both type-wise and macro-expansion-wise. So switch the macro to an inline. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220503063122.20957-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: pic32: remove pic32_get_port() macroJiri Slaby
It's just &sport->port. First, sport was not in parenthesis, so macro expansion could be an issue. Second, it's so simple, that we can expand the macro and make the code really straightforward. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220503063122.20957-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: pic32: simplify pic32_sport::enable_tx_irq handlingJiri Slaby
Make it a bool, so use true+false. And remove the wrap-around macro -- i.e. access the member directly. It makes the code more obvious. BTW the macro did not have 'sport' in parentheses, so it was potentially problematic wrt expansion. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220503063122.20957-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: pic32: simplify clk handlingJiri Slaby
struct pic32_sport::ref_clk is only set, but not read. That means we can remove it. And when we do so, pic32_enable_clock() and pic32_disable_clock() are simple wrappers around clk_prepare_enable() and clk_disable_unprepare() respectively. So we can remove the former two from the code and replace it by the latter two. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220503063122.20957-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: pic32: remove constants from struct pic32_sportJiri Slaby
All the irqflags_* in struct pic32_sport are set to IRQF_NO_THREAD and never updated. So remove pic32_sport::irqflags_* and use the flag directly. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220503063122.20957-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: pic32: move header content to .cJiri Slaby
There is no point keeping the header content separated. So move the content to the appropriate source file. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220503063122.20957-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: pic32: remove unused items from the headerJiri Slaby
struct pic32_console_opt and its support are unused in pic32. So remove all that. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220503063122.20957-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: stm32: Use TC interrupt to deassert GPIO RTS in RS485 modeMarek Vasut
In case the RS485 mode is emulated using GPIO RTS, use the TC interrupt to deassert the GPIO RTS, otherwise the GPIO RTS stays asserted after a transmission ended and the RS485 cannot work. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Erwan Le Ray <erwan.leray@foss.st.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jean Philippe Romain <jean-philippe.romain@foss.st.com> Cc: Valentin Caron <valentin.caron@foss.st.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-stm32@st-md-mailman.stormreply.com To: linux-serial@vger.kernel.org Link: https://lore.kernel.org/r/20220430162845.244655-2-marex@denx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: stm32: Factor out GPIO RTS toggling into separate functionMarek Vasut
Pull out the GPIO RTS enable and disable handling into separate function. Limit the scope of GPIO RTS toggling only to GPIO emulated RS485 too. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Erwan Le Ray <erwan.leray@foss.st.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jean Philippe Romain <jean-philippe.romain@foss.st.com> Cc: Valentin Caron <valentin.caron@foss.st.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-stm32@st-md-mailman.stormreply.com To: linux-serial@vger.kernel.org Link: https://lore.kernel.org/r/20220430162845.244655-1-marex@denx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: sifive: Remove duplicate `clkin_rate' settingMaciej W. Rozycki
The `clkin_rate' member of `struct sifive_serial_port' now duplicates `uartclk' from nested `struct uart_port', so use `uartclk' throughout and remove `clkin_rate'. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204291656150.9383@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: sifive: Report actual baud base rather than fixed 115200Maciej W. Rozycki
The base baud value reported is supposed to be the highest baud rate that can be set for a serial port. The SiFive FU740-C000 SOC's on-chip UART supports baud rates of up to 1/16 of the input clock rate, which is the bus clock `tlclk'[1], often at 130MHz in the case of the HiFive Unmatched board. However the sifive UART driver reports a fixed value of 115200 instead: 10010000.serial: ttySIF0 at MMIO 0x10010000 (irq = 1, base_baud = 115200) is a SiFive UART v0 10011000.serial: ttySIF1 at MMIO 0x10011000 (irq = 2, base_baud = 115200) is a SiFive UART v0 even though we already support setting higher baud rates, e.g.: $ tty /dev/ttySIF1 $ stty speed 230400 The baud base value is computed by the serial core by dividing the UART clock recorded in `struct uart_port' by 16, which is also the minimum value of the clock divider supported, so correct the baud base value reported by setting the UART clock recorded to the input clock rate rather than 115200: 10010000.serial: ttySIF0 at MMIO 0x10010000 (irq = 1, base_baud = 8125000) is a SiFive UART v0 10011000.serial: ttySIF1 at MMIO 0x10011000 (irq = 2, base_baud = 8125000) is a SiFive UART v0 References: [1] "SiFive FU740-C000 Manual", v1p3, SiFive, Inc., August 13, 2021, Section 16.9 "Baud Rate Divisor Register (div)", pp.143-144 Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Fixes: 1f1496a923b6 ("riscv: Fix sifive serial driver") Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204291656280.9383@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: 8250: Add proper clock handling for OxSemi PCIe devicesMaciej W. Rozycki
Oxford Semiconductor PCIe (Tornado) 950 serial port devices are driven by a fixed 62.5MHz clock input derived from the 100MHz PCI Express clock. We currently drive the device using its default oversampling rate of 16 and the clock prescaler disabled, consequently yielding the baud base of 3906250. This base is inadequate for some of the high-speed baud rates such as 460800bps, for which the closest rate possible can be obtained by dividing the baud base by 8, yielding the baud rate of 488281.25bps, which is off by 5.9638%. This is enough for data communication to break with the remote end talking actual 460800bps, where missed stop bits have been observed. We can do better however, by taking advantage of a reduced oversampling rate, which can be set to any integer value from 4 to 16 inclusive by programming the TCR register, and by using the clock prescaler, which can be set to any value from 1 to 63.875 in increments of 0.125 in the CPR/CPR2 register pair. The prescaler has to be explicitly enabled though by setting bit 7 in the MCR or otherwise it is bypassed (in the enhanced mode that we enable) as if the value of 1 was used. Make use of these features then as follows: - Set the baud base to 15625000, reflecting the minimum oversampling rate of 4 with the clock prescaler and divisor both set to 1. - Override the `set_mctrl' and set the MCR shadow there so as to have MCR[7] always set and have the 8250 core propagate these settings. - Override the `get_divisor' handler and determine a good combination of parameters by using a lookup table with predetermined value pairs of the oversampling rate and the clock prescaler and finding a pair that divides the input clock such that the quotient, when rounded to the nearest integer, deviates the least from the exact result. Calculate the clock divisor accordingly. Scale the resulting oversampling rate (only by powers of two) if possible so as to maximise it, reducing the divisor accordingly, and avoid a divisor overflow for very low baud rates by scaling the oversampling rate and/or the prescaler even if that causes some accuracy loss. Also handle the historic spd_cust feature so as to allow one to set all the three parameters manually to arbitrary values, by keeping the low 16 bits for the divisor and then putting TCR in bits 19:16 and CPR/CPR2 in bits 28:20, sanitising the bit pattern supplied such as to clamp CPR/CPR2 values between 0.000 and 0.875 inclusive to 33.875. This preserves compatibility with any existing setups, that is where requesting a custom divisor that only has any bits set among the low 16 the oversampling rate of 16 and the clock prescaler of 33.875 will be used as with the original 8250. Finally abuse the `frac' argument to store the determined bit patterns for the TCR, CPR and CPR2 registers. - Override the `set_divisor' handler so as to set the TCR, CPR and CPR2 registers from the `frac' value supplied. Set the divisor as usual. With the baud base set to 15625000 and the unsigned 16-bit UART_DIV_MAX limitation imposed by `serial8250_get_baud_rate' standard baud rates below 300bps become unavailable in the regular way, e.g. the rate of 200bps requires the baud base to be divided by 78125 and that is beyond the unsigned 16-bit range. The historic spd_cust feature can still be used to obtain such rates if so required. See Documentation/tty/device_drivers/oxsemi-tornado.rst for more details. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181519450.9383@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: 8250: Export ICR access helpers for internal useMaciej W. Rozycki
Make ICR access helpers available outside 8250_port.c, however retain them as ordinary static functions so as not to regress code generation. This is because `serial_icr_write' is currently automatically inlined by GCC, however `serial_icr_read' is not. Making them both static inline would grow code produced, e.g.: $ i386-linux-gnu-size --format=gnu 8250_port-{old,new}.o text data bss total filename 15065 3378 0 18443 8250_port-old.o 15289 3378 0 18667 8250_port-new.o and: $ riscv64-linux-gnu-size --format=gnu 8250_port-{old,new}.o text data bss total filename 16980 5306 0 22286 8250_port-old.o 17124 5306 0 22430 8250_port-new.o while making them external would needlessly add a new module interface and lose the benefit from `serial_icr_write' getting inlined outside 8250_port.o. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181517500.9383@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: 8250: Fold EndRun device support into OxSemi Tornado codeMaciej W. Rozycki
The EndRun PTP/1588 dual serial port device is based on the Oxford Semiconductor OXPCIe952 UART device with the PCI vendor:device ID set for EndRun Technologies and uses the same sequence to determine the number of ports available. Despite that we have duplicate code specific to the EndRun device. Remove redundant code then and factor out OxSemi Tornado device detection. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181516220.9383@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: men_z135_uart: Drop duplicated iotype assignmentIlpo Järvinen
The driver assigns same iotype twice. Drop one of them. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/14b71e1-2396-3d83-3a97-9582765d453@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: 8250: pxa: Remove unneeded <linux/pm_runtime.h>Geert Uytterhoeven
The 8250 PXA driver never used Runtime PM, so there was never a need to include <linux/pm_runtime.h>. Fixes: ab28f51c77cd4618 ("serial: rewrite pxa2xx-uart to use 8250_core") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/9fd96fba9bbbbdeb16af0dc07ae9dee21c8e297c.1651494971.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-05serial: 8250: core: Remove unneeded <linux/pm_runtime.h>Geert Uytterhoeven
The last calls into Runtime PM were moved to 8250_port.c a long time ago. Fixes: b6830f6df8914faa ("serial: 8250: Split base port operations from universal driver") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/2545eaa7fc552013a5d04c4df027255204e64834.1651494971.git.geert+renesas@glider.be 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>
2022-05-02Merge 5.18-rc5 into tty-nextGreg Kroah-Hartman
We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250_dwlib: Implement SW half duplex supportIlpo Järvinen
This patch enables support for SW half-duplex mode using em485. Cc: Eric Tremblay <etremblay@distech-controls.com> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Tested-by: Vicente Bergas <vicencb@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220426122448.38997-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250_dwlib: RS485 HW half & full duplex supportIlpo Järvinen
The Synopsys DesignWare UART can be configured to have HW support for the RS485 protocol from IP version 4.0 onward. Add support for hardware-controlled half duplex and full duplex modes. HW will take care of managing DE and RE, the driver just gives it permission to use either by setting both to 1. To ask for full duplex mode, userspace sets SER_RS485_RX_DURING_TX flag and HW will take care of the rest. Set delay_rts_before_send and delay_rts_after_send to zero for now. The granularity of that ABI is too coarse to be useful. Co-developed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Co-developed-by: Raymond Tan <raymond.tan@intel.com> Signed-off-by: Raymond Tan <raymond.tan@intel.com> Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220426122448.38997-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: Handle UART without interrupt on TEMTIlpo Järvinen
Add UART_CAP_NOTEMT for UARTs that lack interrupt on TEMT but want to use em485. Em485 framework needs to ensure not only FIFO is empty but also that tx shift register is empty. This approach uses Uwe Kleine-König's suggestion on simply using/incrementing stop_tx timer rather than adding another timer. When UART_CAP_NOTEMT is set and THRE is present w/o TEMT, stop tx timer is reused to wait for the emptying of the shift register. This change does not add the UART_CAP_NOTEMT define as it already exist but is currently no-op. See 7a107b2c6b81 (Revert "serial: 8250: Handle UART without interrupt on TEMT using em485") for further details. Vicente Bergas reported that RTS is deasserted roughly one bit too early losing stop bit tx. To address this problem, stop_delay now accounts for one extra bit using rough formula /7 (assumes worst-case of 2+5 bits). I suspect this glitch had to do with when THRE is getting asserted. If FIFO is emptied already during the tx of the stop bit, perhaps it leads to HW asserting THRE early for the normal frame time formula to work accurately. Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Eric Tremblay <etremblay@distech-controls.com> Tested-by: Vicente Bergas <vicencb@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220425143410.12703-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: use THRE & __stop_tx also with DMAIlpo Järvinen
8250 DMA tx complete path lacks calls to normal 8250 stop handling. It does not use THRE to detect true completion of the tx and also doesn't call __stop_tx. This leads to problems with em485 that needs to handle RTS timing. Instead of handling tx stop internally within 8250 dma code, enable THRE when tx'able data runs out and tweak serial8250_handle_irq to call only __stop_tx when uart is using DMA. It also seems bit early to call serial8250_rpm_put_tx from there while tx is still underway(?). Tested-by: Vicente Bergas <vicencb@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220425143410.12703-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: Store character timing information to uart_portIlpo Järvinen
Struct uart_port currently stores FIFO timeout. Having character timing information readily available is useful. Even serial core itself determines char_time from port->timeout using inverse calculation. Store frame_time directly into uart_port. Character time is stored in nanoseconds to have reasonable precision with high rates. To avoid overflow, 64-bit math is necessary. It might be possible to determine timeout from frame_time by multiplying it with fifosize as needed but only part of the users seem to be protected by a lock. Thus, this patch does not pursue storing only frame_time in uart_port. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220425143410.12703-2-ilpo.jarvinen@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: Move the IO accessors to 8250_dwlib.hMiquel Raynal
These accessors should be used instead of the regular readl/writel() helpers. In order to use them also from 8250_dw.c in this directory, move the helpers to 8250_dwlib.h There is no functional change. There is no need for declaring `struct uart_port` or even UPIO_MEM32BE which both are already included in the 8250_dwlib.h header by 8250.h. Suggested-by: Ilpo Järvinen <ilpo.jarvinen@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/20220422180615.9098-8-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: dma: Allow driver operations before starting DMA transfersMiquel Raynal
One situation where this could be used is when configuring the UART controller to be the DMA flow controller. This is a typical case where the driver might need to program a few more registers before starting a DMA transfer. Provide the necessary infrastructure to support this case. 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/20220422180615.9098-6-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Allow to use a fallback CPR value if not synthesizedMiquel Raynal
DW UART controllers can be synthesized without the CPR register. In this case, allow to the platform information to provide a CPR value. Co-developed-by: Phil Edworthy <phil.edworthy@renesas.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/20220422180615.9098-5-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>
2022-04-26sysrq: do not omit current cpu when showing backtrace of all active CPUsChangbin Du
The backtrace of current CPU also should be printed as it is active. This change add stack trace for current CPU and print a hint for idle CPU for the generic workqueue based printing. (x86 already does this) Now it looks like below: [ 279.401567] sysrq: Show backtrace of all active CPUs [ 279.407234] sysrq: CPU5: [ 279.407505] Call Trace: [ 279.408789] [<ffffffff8000606c>] dump_backtrace+0x2c/0x3a [ 279.411698] [<ffffffff800060ac>] show_stack+0x32/0x3e [ 279.411809] [<ffffffff80542258>] sysrq_handle_showallcpus+0x4c/0xc6 [ 279.411929] [<ffffffff80542f16>] __handle_sysrq+0x106/0x26c [ 279.412034] [<ffffffff805436a8>] write_sysrq_trigger+0x64/0x74 [ 279.412139] [<ffffffff8029cd48>] proc_reg_write+0x8e/0xe2 [ 279.412252] [<ffffffff8021a8f8>] vfs_write+0x90/0x2be [ 279.412362] [<ffffffff8021acd2>] ksys_write+0xa6/0xce [ 279.412467] [<ffffffff8021ad24>] sys_write+0x2a/0x38 [ 279.412689] [<ffffffff80003ff8>] ret_from_syscall+0x0/0x2 [ 279.417173] sysrq: CPU6: backtrace skipped as idling [ 279.417185] sysrq: CPU4: backtrace skipped as idling [ 279.417187] sysrq: CPU0: backtrace skipped as idling [ 279.417181] sysrq: CPU7: backtrace skipped as idling [ 279.417190] sysrq: CPU1: backtrace skipped as idling [ 279.417193] sysrq: CPU3: backtrace skipped as idling [ 279.417219] sysrq: CPU2: [ 279.419179] Call Trace: [ 279.419440] [<ffffffff8000606c>] dump_backtrace+0x2c/0x3a [ 279.419782] [<ffffffff800060ac>] show_stack+0x32/0x3e [ 279.420015] [<ffffffff80542b30>] showacpu+0x5c/0x96 [ 279.420317] [<ffffffff800ba71c>] flush_smp_call_function_queue+0xd6/0x218 [ 279.420569] [<ffffffff800bb438>] generic_smp_call_function_single_interrupt+0x14/0x1c [ 279.420798] [<ffffffff800079ae>] handle_IPI+0xaa/0x13a [ 279.421024] [<ffffffff804dcb92>] riscv_intc_irq+0x56/0x70 [ 279.421274] [<ffffffff80a05b70>] generic_handle_arch_irq+0x6a/0xfa [ 279.421518] [<ffffffff80004006>] ret_from_exception+0x0/0x10 [ 279.421750] [<ffffffff80096492>] rcu_idle_enter+0x16/0x1e Signed-off-by: Changbin Du <changbin.du@gmail.com> Link: https://lore.kernel.org/r/20220117154300.2808-1-changbin.du@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26tty: hvcs: simplify if-if to if-elseWan Jiabing
Use if and else instead of if(A) and if (!A) and fix a coding style. Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> Link: https://lore.kernel.org/r/20220424091310.98780-1-wanjiabing@vivo.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26tty/hvc_opal: simplify if-if to if-elseWan Jiabing
Use if and else instead of if(A) and if (!A). Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> Link: https://lore.kernel.org/r/20220426071041.168282-1-wanjiabing@vivo.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26tty: n_gsm: fix sometimes uninitialized warning in gsm_dlci_modem_output()Daniel Starke
'size' may be used uninitialized in gsm_dlci_modem_output() if called with an adaption that is neither 1 nor 2. The function is currently only called by gsm_modem_upd_via_data() and only for adaption 2. Properly handle every invalid case by returning -EINVAL to silence the compiler warning and avoid future regressions. Fixes: c19ffe00fed6 ("tty: n_gsm: fix invalid use of MSC in advanced option") Cc: stable@vger.kernel.org Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220425104726.7986-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22printk: add functions to prefer direct printingJohn Ogness
Once kthread printing is available, console printing will no longer occur in the context of the printk caller. However, there are some special contexts where it is desirable for the printk caller to directly print out kernel messages. Using pr_flush() to wait for threaded printers is only possible if the caller is in a sleepable context and the kthreads are active. That is not always the case. Introduce printk_prefer_direct_enter() and printk_prefer_direct_exit() functions to explicitly (and globally) activate/deactivate preferred direct console printing. The term "direct console printing" refers to printing to all enabled consoles from the context of the printk caller. The term "prefer" is used because this type of printing is only best effort. If the console is currently locked or other printers are already actively printing, the printk caller will need to rely on the other contexts to handle the printing. This preferred direct printing is how all printing has been handled until now (unless it was explicitly deferred). When kthread printing is introduced, there may be some unanticipated problems due to kthreads being unable to flush important messages. In order to minimize such risks, preferred direct printing is activated for the primary important messages when the system experiences general types of major errors. These are: - emergency reboot/shutdown - cpu and rcu stalls - hard and soft lockups - hung tasks - warn - sysrq Note that since kthread printing does not yet exist, no behavior changes result from this commit. This is only implementing the counter and marking the various places where preferred direct printing is active. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> # for RCU Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-13-john.ogness@linutronix.de
2022-04-22serial: 8250: Correct the clock for EndRun PTP/1588 PCIe deviceMaciej W. Rozycki
The EndRun PTP/1588 dual serial port device is based on the Oxford Semiconductor OXPCIe952 UART device with the PCI vendor:device ID set for EndRun Technologies and is therefore driven by a fixed 62.5MHz clock input derived from the 100MHz PCI Express clock. The clock rate is divided by the oversampling rate of 16 as it is supplied to the baud rate generator, yielding the baud base of 3906250. Replace the incorrect baud base of 4000000 with the right value of 3906250 then, complementing commit 6cbe45d8ac93 ("serial: 8250: Correct the clock for OxSemi PCIe devices"). Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Cc: stable <stable@kernel.org> Fixes: 1bc8cde46a159 ("8250_pci: Added driver for Endrun Technologies PTP PCIe card.") Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181515270.9383@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: 8250: Also set sticky MCR bits in console restorationMaciej W. Rozycki
Sticky MCR bits are lost in console restoration if console suspending has been disabled. This currently affects the AFE bit, which works in combination with RTS which we set, so we want to make sure the UART retains control of its FIFO where previously requested. Also specific drivers may need other bits in the future. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Fixes: 4516d50aabed ("serial: 8250: Use canary to restart console after suspend") Cc: stable@vger.kernel.org # v4.0+ Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181518490.9383@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: n_gsm: fix software flow control handlingDaniel Starke
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.4.8.1 states that XON/XOFF characters shall be used instead of Fcon/Fcoff command in advanced option mode to handle flow control. Chapter 5.4.8.2 describes how XON/XOFF characters shall be handled. Basic option mode only used Fcon/Fcoff commands and no XON/XOFF characters. These are treated as data bytes here. The current implementation uses the gsm_mux field 'constipated' to handle flow control from the remote peer and the gsm_dlci field 'constipated' to handle flow control from each DLCI. The later is unrelated to this patch. The gsm_mux field is correctly set for Fcon/Fcoff commands in gsm_control_message(). However, the same is not true for XON/XOFF characters in gsm1_receive(). Disable software flow control handling in the tty to allow explicit handling by n_gsm. Add the missing handling in advanced option mode for gsm_mux in gsm1_receive() to comply with the standard. This patch depends on the following commit: Commit 8838b2af23ca ("tty: n_gsm: fix SW flow control encoding/handling") Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220422071025.5490-3-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: n_gsm: fix invalid use of MSC in advanced optionDaniel Starke
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.4.6.3.7 states that the Modem Status Command (MSC) shall only be used if the basic option was chosen. The current implementation uses MSC frames even if advanced option was chosen to inform the peer about modem line state updates. A standard conform peer may choose to discard these frames in advanced option mode. Furthermore, gsmtty_modem_update() is not part of the 'tty_operations' functions despite its name. Rename gsmtty_modem_update() to gsm_modem_update() to clarify this. Split its function into gsm_modem_upd_via_data() and gsm_modem_upd_via_msc() depending on the encoding and adaption. Introduce gsm_dlci_modem_output() as adaption of gsm_dlci_data_output() to encode and queue empty frames in advanced option mode. Use it in gsm_modem_upd_via_data(). gsm_modem_upd_via_msc() is based on the initial gsmtty_modem_update() function which used only MSC frames to update modem states. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220422071025.5490-2-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: n_gsm: fix broken virtual tty handlingDaniel Starke
Dynamic virtual tty registration was introduced to allow the user to handle these cases with uevent rules. The following commits relate to this: Commit 5b87686e3203 ("tty: n_gsm: Modify gsmtty driver register method when config requester") Commit 0b91b5332368 ("tty: n_gsm: Save dlci address open status when config requester") Commit 46292622ad73 ("tty: n_gsm: clean up indenting in gsm_queue()") However, the following behavior can be seen with this implementation: - n_gsm ldisc is activated via ioctl - all configuration parameters are set to their default value (initiator=0) - the mux gets activated and attached and gsmtty0 is being registered in in gsm_dlci_open() after DLCI 0 was established (DLCI 0 is the control channel) - the user configures n_gsm via ioctl GSMIOC_SETCONF as initiator - this re-attaches the n_gsm mux - no new gsmtty devices are registered in gsmld_attach_gsm() because the mux is already active - the initiator side registered only the control channel as gsmtty0 (which should never happen) and no user channel tty The commits above make it impossible to operate the initiator side as no user channel tty is or will be available. On the other hand, this behavior will make it also impossible to allow DLCI parameter negotiation on responder side in the future. The responder side first needs to provide a device for the application before the application can set its parameters of the associated DLCI via ioctl. Note that the user application is still able to detect a link establishment without relaying to uevent by waiting for DTR open on responder side. This is the same behavior as on a physical serial interface. And on initiator side a tty hangup can be detected if a link establishment request failed. Revert the commits above completely to always register all user channels and no control channel after mux attachment. No other changes are made. Fixes: 5b87686e3203 ("tty: n_gsm: Modify gsmtty driver register method when config requester") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220422071025.5490-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22Revert "serial: sc16is7xx: Clear RS485 bits in the shutdown"Hui Wang
This reverts commit 927728a34f11b5a27f4610bdb7068317d6fdc72a. Once the uart_port->rs485->flag is set to SER_RS485_ENABLED, the port should always work in RS485 mode. If users want the port to leave RS485 mode, they need to call ioctl() to clear SER_RS485_ENABLED. So here we shouldn't clear the RS485 bits in the shutdown(). Fixes: 927728a34f11 ("serial: sc16is7xx: Clear RS485 bits in the shutdown") Signed-off-by: Hui Wang <hui.wang@canonical.com> Link: https://lore.kernel.org/r/20220418094339.678144-1-hui.wang@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: stm32: add earlycon supportValentin Caron
Add early console support in stm32 uart driver. Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220419085330.1178925-4-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: stm32: add KGDB supportValentin Caron
Add support for KGDB in stm32 serial driver by implementing characters polling callbacks (poll_init, poll_get_char and poll_put_char). Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Signed-off-by: Jean Philippe Romain <jean-philippe.romain@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220419085330.1178925-3-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: stm32: remove infinite loop possibility in putchar functionValentin Caron
Rework stm32_usart_console_putchar() function in order to anticipate the case where the character can never be sent. Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220419085330.1178925-2-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: Add function for handling flow control charsIlpo Järvinen
Move receive path flow control character handling to own function. No functional changes. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220411094859.10894-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: core: fix tcdrain() with CTS enabledTomasz Moń
Do not set timeout to twice the approximate amount of time to send the entire FIFO if CTS is enabled. If the caller requested no timeout, e.g. when userspace program called tcdrain(), then wait without any timeout. Premature return from tcdrain() was observed on imx based system which has 32 character long transmitter FIFO with hardware CTS handling. Simple userspace application that reproduces problem has to: * Open tty device, enable hardware flow control (CRTSCTS) * Write data, e.g. 26 bytes * Call tcdrain() to wait for the transmitter * Close tty device The other side of serial connection has to: * Receive some data, e.g. 10 bytes * Set RTS output (CTS input from sender perspective) inactive for at least twice the port timeout * Try to receive remaining data Without this patch, userspace application will finish without any error while the other side of connection will never receive remaining data. Signed-off-by: Tomasz Moń <tomasz.mon@camlingroup.com> Link: https://lore.kernel.org/r/20220228054911.1420221-1-tomasz.mon@camlingroup.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>