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* serial: make uart_console_write->putchar()'s character an unsigned charJiri Slaby2022-03-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, uart_console_write->putchar's second parameter (the character) is of type int. It makes little sense, provided uart_console_write() accepts the input string as "const char *s" and passes its content -- the characters -- to putchar(). So switch the character's type to unsigned char. We don't use char as that is signed on some platforms. That would cause troubles for drivers which (implicitly) cast the char to u16 when writing to the device. Sign extension would happen in that case and the value written would be completely different to the provided char. DZ is an example of such a driver -- on MIPS, it uses u16 for dz_out in dz_console_putchar(). Note we do the char -> uchar conversion implicitly in uart_console_write(). Provided we do not change size of the data type, sign extension does not happen there, so the problem is void. This makes the types consistent and unified with the rest of the uart layer, which uses unsigned char in most places already. One exception is xmit_buf, but that is going to be converted later. Cc: Paul Cercueil <paul@crapouillou.net> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Ludovic Desroches <ludovic.desroches@microchip.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@orcam.me.uk> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: NXP Linux Team <linux-imx@nxp.com> Cc: Karol Gugala <kgugala@antmicro.com> Cc: Mateusz Holenko <mholenko@antmicro.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Neil Armstrong <narmstrong@baylibre.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Jerome Brunet <jbrunet@baylibre.com> Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Cc: Taichi Sugaya <sugaya.taichi@socionext.com> Cc: Takao Orito <orito.takao@socionext.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Andy Gross <agross@kernel.org> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Cc: Orson Zhai <orsonzhai@gmail.com> Cc: Baolin Wang <baolin.wang7@gmail.com> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Patrice Chotard <patrice.chotard@foss.st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <peter@korsgaard.com> Cc: Michal Simek <michal.simek@xilinx.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> [atmel_serial] Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Paul Cercueil <paul@crapouillou.net> Acked-by: Neil Armstrong <narmstrong@baylibre.com> # meson_serial Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220303080831.21783-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: fix return value check in mvebu_uart_clock_probe()Wei Yongjun2022-03-011-4/+4
| | | | | | | | | | | | | In case of error, the function devm_ioremap() returns NULL pointer not ERR_PTR(). The IS_ERR() test in the return value check should be replaced with NULL test. Fixes: b7e2b5360f9b ("serial: mvebu-uart: implement UART clock driver for configuring UART base clock") Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Pali Rohár <pali@kernel.org> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Link: https://lore.kernel.org/r/20220301075806.3950108-1-weiyongjun1@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: implement support for baudrates higher than 230400 BdPali Rohár2022-02-251-18/+65
| | | | | | | | | | | | | | | | | | | | | | Implement simple usage of fractional divisor. When main divisor D is too large to represent requested baudrate then use divisor M from the fractional divisor feature. All the M prescalers are set to the same and maximal value 63, so the fractional part of the fractional divisor is not used at all. We also determine upper limit for possible baudrates. Experiments show that UART at baudrate 1500000 Bd with this configuration is stable. So there is no need to implement complicated calculation of fractional coefficients yet. To use this feature with higher baudrates, it is required to use UART clock provided by UART clock driver. Default boot xtal clock is not capable of higher baudrates. Reviewed-by: Marek Behún <kabel@kernel.org> Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Marek Behún <kabel@kernel.org> Link: https://lore.kernel.org/r/20220219152818.4319-6-kabel@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: implement UART clock driver for configuring UART base clockPali Rohár2022-02-251-2/+519
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement a new device driver for controlling UART clocks on Marvell Armada 3700 SoC. This device driver is loaded for devices which match the compatible string "marvell,armada-3700-uart-clock". There are more pitfalls related to UART clocks: - both UARTs use same parent clock source (which can be xtal or one of the TBG clocks), - if a TBG clock is used as the parent clock, there are two additional divisors that can both be configured to divide the rate by 1, 2, ... 6, but these divisors are again shared between the two UART controllers on the SOC, - the configuration of the parent clock source and divisors is done in the address space of the first UART controller, UART1. Clocks can be gated separately for UART1 and UART2, but this setting also lives in the address space of UART1, - Marvell's Functional Specification for Armada 3720 document has the clock gating bits swapped, so the one described to gate UART1 clock actually gates UART2 and vice versa, - each UART has it's own "special divisor", and this uses the parent clock described above. These divisors are configure in each UART's address space separately. Thus the driver for UART2 controller needs to have access to UART1 address space, since UART1 address space contains some bits exclusive for UART2 and also some bits which are shared between UART1 and UART2. Also, during boot, when early console is active on one of the UARTs, and we want to switch parent clock from xtal (default) to TBG (to be more flexible with baudrates), the driver changing UART clocks also needs to be able to change the "special divisor", so that the baudrate of earlycon is not changed when swtiching to normal console. Thus the clock driver also needs to be able to access UART2 register space, for UART2's "special divisor". For these reasons, this new UART clock driver does not use ioremap_resource(), but only ioremap() to prevent resource conflicts between UART clock driver and UART driver. We need to share only two 32-bit registers between the UART driver and the UART clock driver: - UART Clock Control - UART 2 Baud Rate Divisor Access to these two registers are protected by one spinlock to prevent any conflicts. Access is required only during probing, when changing baudrate or during suspend/resume. Hardware can be configured to use one of following clocks as UART parent clock: TBG-A-P, TBG-B-P, TBG-A-S, TBG-B-S, xtal. Not every clock is usable for higher buadrates. Any subset can be specified in the device-tree and the driver will choose the best one which also still supports the mandatory baudrate of 9600 Bd. For smooth boot log output it is needed to specify clock used by early console, otherwise garbage would be printed on UART during probe of UART clock driver and transitioning from early console to normal console. We are implementing this to be able to configure TBG clock as UART parent clock, which is required to be able to achieve higher baudrates than 230400 Bd. We achieve this by referencing this new UART clock device node in UART's device node. UART clock device driver automatically chooses the best clock source for UART driver. Until now, UART's device-tree node needed to reference one of the static clocks (xtal or one of the TBGs) as parent clock in the `clocks` phandle - the parent clock which was configured before booting the kernel. If bootloader changed UART's parent clock, it needed to change the `clocks` phandle in DTB correspondingly before booting. From now on both the old mechanism (xtal or TBG referenced as parent clock in `clocks` phandle) and the new one (UART clock referenced in the `clocks` phandle) are supported, to provide full backward compatibility with existing DTS files, full backward compatibility with existing boot loaders, and to provide new features (runtime clock configuration to allow higher baudrates than 230400 Bd). New features are available only with new DTS files. There was also a discussion about how the UART node and the clock-controller node could be wrapped together in a new binding [1, 2]. As explained there, this is not possible if we want to keep backwards compatibility with existing bootloaders, and thus we are doing this by putting the UART clock-controller node inside the UART1 node. [1] https://lore.kernel.org/linux-serial/20220120000651.in7s6nazif5qjkme@pali/ [2] https://lore.kernel.org/linux-serial/20220125204006.A6D09C340E0@smtp.kernel.org/ Reviewed-by: Marek Behún <kabel@kernel.org> Reviewed-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Marek Behún <kabel@kernel.org> Link: https://lore.kernel.org/r/20220219152818.4319-4-kabel@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: fix driver's tx_empty callbackPali Rohár2021-09-141-1/+1
| | | | | | | | | | | | | | | | | | | | Driver's tx_empty callback should signal when the transmit shift register is empty. So when the last character has been sent. STAT_TX_FIFO_EMP bit signals only that HW transmit FIFO is empty, which happens when the last byte is loaded into transmit shift register. STAT_TX_EMP bit signals when the both HW transmit FIFO and transmit shift register are empty. So replace STAT_TX_FIFO_EMP check by STAT_TX_EMP in mvebu_uart_tx_empty() callback function. Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Cc: stable <stable@vger.kernel.org> Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20210911132017.25505-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: remove unused member nb from struct mvebu_uartPali Rohár2021-06-251-1/+0
| | | | | | | | Member nb in struct mvebu_uart is not set nor read. So remove it completely. Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20210624224909.6350-7-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: correctly calculate minimal possible baudratePali Rohár2021-06-251-3/+8
| | | | | | | | | | | | For default (x16) scheme which is currently used by mvebu-uart.c driver, maximal divisor of UART base clock is 1023*16. Therefore there is limit for minimal supported baudrate. This change calculate it correctly and prevents setting invalid divisor 0 into hardware registers. Signed-off-by: Pali Rohár <pali@kernel.org> Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate") Link: https://lore.kernel.org/r/20210624224909.6350-4-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: do not allow changing baudrate when uartclk is not availablePali Rohár2021-06-251-3/+2
| | | | | | | | | | | | | | | | | | Testing mvuart->clk for non-error is not enough as mvuart->clk may contain valid clk pointer but when clk_prepare_enable(mvuart->clk) failed then port->uartclk is zero. When mvuart->clk is not available then port->uartclk is zero too. Parent clock rate port->uartclk is needed to calculate UART clock divisor and without it is not possible to change baudrate. So fix test condition when it is possible to change baudrate. Signed-off-by: Pali Rohár <pali@kernel.org> Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate") Link: https://lore.kernel.org/r/20210624224909.6350-3-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: fix calculation of clock divisorPali Rohár2021-06-251-1/+1
| | | | | | | | | | The clock divisor should be rounded to the closest value. Signed-off-by: Pali Rohár <pali@kernel.org> Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate") Cc: stable@vger.kernel.org # 0e4cf69ede87 ("serial: mvebu-uart: clarify the baud rate derivation") Link: https://lore.kernel.org/r/20210624224909.6350-2-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Prefer unsigned int to bare use of unsignedJinchao Wang2021-06-241-1/+1
| | | | | | | | | Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' Signed-off-by: Jinchao Wang <wjc@cdjrlc.com> Link: https://lore.kernel.org/r/20210624021207.58059-1-wjc@cdjrlc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "serial: mvebu-uart: Fix to avoid a potential NULL pointer dereference"Greg Kroah-Hartman2021-05-131-3/+0
| | | | | | | | | | | | | | | | | | | This reverts commit 32f47179833b63de72427131169809065db6745e. Because of recent interactions with developers from @umn.edu, all commits from them have been recently re-reviewed to ensure if they were correct or not. Upon review, this commit was found to be not be needed at all as the change was useless because this function can only be called when of_match_device matched on something. So it should be reverted. Cc: Aditya Pakki <pakki001@umn.edu> Cc: stable <stable@vger.kernel.org> Fixes: 32f47179833b ("serial: mvebu-uart: Fix to avoid a potential NULL pointer dereference") Acked-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20210503115736.2104747-6-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: fix tx lost characters at power offPali Rohár2020-12-281-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | Commit c685af1108d7 ("serial: mvebu-uart: fix tx lost characters") fixed tx lost characters at low baud rates but started causing tx lost characters when kernel is going to power off or reboot. TX_EMP tells us when transmit queue is empty therefore all characters were transmitted. TX_RDY tells us when CPU can send a new character. Therefore we need to use different check prior transmitting new character and different check after all characters were sent. This patch splits polling code into two functions: wait_for_xmitr() which waits for TX_RDY and wait_for_xmite() which waits for TX_EMP. When rebooting A3720 platform without this patch on UART is print only: [ 42.699� And with this patch on UART is full output: [ 39.530216] reboot: Restarting system Fixes: c685af1108d7 ("serial: mvebu-uart: fix tx lost characters") Signed-off-by: Pali Rohár <pali@kernel.org> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20201223191931.18343-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: fix unused variable warningQinglang Miao2020-09-291-1/+1
| | | | | | | | | | | | There's a warning shows that 'ret' becomes an unused variable after simplify the return expression of mvebu_uart_probe(). So remove it. Fixes: b63537020db3 ("serial: mvebu-uart: simplify the return expression of mvebu_uart_probe()") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> Link: https://lore.kernel.org/r/20200929085651.158283-1-miaoqinglang@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: simplify the return expression of mvebu_uart_probe()Qinglang Miao2020-09-271-4/+1
| | | | | | | | Simplify the return expression. Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> Link: https://lore.kernel.org/r/20200921131105.93177-1-miaoqinglang@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty:serial:mvebu-uart:fix a wrong returntangbin2020-03-051-1/+1
| | | | | | | | | | | | in this place, the function should return a negative value and the PTR_ERR already returns a negative,so return -PTR_ERR() is wrong. Signed-off-by: tangbin <tangbin@cmss.chinamobile.com> Cc: stable <stable@vger.kernel.org> Acked-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200305013823.20976-1-tangbin@cmss.chinamobile.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Remove dev_err() usage after platform_get_irq()Stephen Boyd2019-09-041-9/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We don't need dev_err() messages when platform_get_irq() fails now that platform_get_irq() prints an error message itself when something goes wrong. Let's remove these prints with a simple semantic patch. // <smpl> @@ expression ret; struct platform_device *E; @@ ret = ( platform_get_irq(E, ...) | platform_get_irq_byname(E, ...) ); if ( \( ret < 0 \| ret <= 0 \) ) { ( -if (ret != -EPROBE_DEFER) -{ ... -dev_err(...); -... } | ... -dev_err(...); ) ... } // </smpl> While we're here, remove braces on if statements that only have one statement (manually). Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20190730181557.90391-45-swboyd@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: Fix to avoid a potential NULL pointer dereferenceAditya Pakki2019-03-191-0/+3
| | | | | | | | | of_match_device on failure to find a matching device can return a NULL pointer. The patch checks for such a scenrio and passes the error upstream. Signed-off-by: Aditya Pakki <pakki001@umn.edu> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: initialize over sampling stack registerMiquel Raynal2018-11-271-1/+6
| | | | | | | | | | | | | | | | The baudrate derivation relies on the state of the programmable over sampling stack (OSAMP register) being empty, while never initializing it. Set all the fields of this register to 0 (except reserved areas) to ensure a x16 divisor, as assumed by the driver. The suspend/resume callbacks are untouched because they already save/restore correctly this register. Suggested-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: clarify the baud rate derivationMiquel Raynal2018-11-271-8/+14
| | | | | | | | | | | The current comment in ->set_baud_rate() is rather incomplete as it fails to describe what are the actual stages for the baudrate derivation. Replace this comment with something more explicit and close to the functional specification. Also adapt the variable names to it. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: Fix reporting of effective CSIZE to userspaceJan Kiszka2018-09-181-0/+1
| | | | | | | | | | | | | | | Apparently, this driver (or the hardware) does not support character length settings. It's apparently running in 8-bit mode, but it makes userspace believe it's in 5-bit mode. That makes tcsetattr with CS8 incorrectly fail, breaking e.g. getty from busybox, thus the login shell on ttyMVx. Fix by hard-wiring CS8 into c_cflag. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Cc: stable <stable@vger.kernel.org> # 4.6+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge 4.17-rc3 into tty-nextGreg Kroah-Hartman2018-04-301-1/+0
|\ | | | | | | | | | | We want the tty and serial driver fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: mvebu-uart: Fix local flags handling on termios updateMarc Zyngier2018-04-221-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 68a0db1d7da2 reworked the baud rate selection, but also added a (not so) subtle change in the way the local flags (c_lflag in the termios structure) are handled, forcing the new flags to always be the same as the old ones. The reason for that particular change is both obscure and undocumented. It also completely breaks userspace. Something as trivial as getty is unusable: <example> Debian GNU/Linux 9 sy-borg ttyMV0 sy-borg login: root root [timeout] Debian GNU/Linux 9 sy-borg ttyMV0 </example> which is quite obvious in retrospect: getty cannot get in control of the echo mode, is stuck in canonical mode, and times out without ever seeing anything valid. It also begs the question of how this change was ever tested. The fix is pretty obvious: stop messing with c_lflag, and the world will be a happier place. Cc: stable@vger.kernel.org # 4.15+ Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate") Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: mvebu-uart: add suspend/resume supportMiquel Raynal2018-04-221-0/+64
|/ | | | | | | | | | | | Add suspend and resume hooks to save/restore the registers content during S2RAM operation. Also save/restore the oversampling rate register (OSAMP) as earlier stages already tuned that register to get a precise UART clock. Suggested-by: Allen Yan <yanwei@marvell.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: fix tx lost charactersGabriel Matni2018-03-221-1/+1
| | | | | | | | | | | | | | | | Fixes missing characters on kernel console at low baud rates (i.e.9600). The driver should poll TX_RDY or TX_FIFO_EMP instead of TX_EMP to ensure that the transmitter holding register (THR) is ready to receive a new byte. TX_EMP tells us when it is possible to send a break sequence via SND_BRK_SEQ. While this also indicates that both the THR and the TSR are empty, it does not guarantee that a new byte can be written just yet. Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Acked-by: Gregory CLEMENT <gregory.clement@bootlin.com> Signed-off-by: Gabriel Matni <gabriel.matni@exfo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: remove duplicated bit-wise or of STAT_FRM_ERRColin Ian King2018-02-281-1/+1
| | | | | | | | Bit pattern STAT_FRM_ERR is being bit-wise or'd twice; remove the redundant 2nd STAT_FRM_ERR Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial: Remove redundant license textGreg Kroah-Hartman2017-11-081-12/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the SPDX tag is in all tty files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Jiri Slaby <jslaby@suse.com> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: add SPDX identifiers to all remaining files in drivers/tty/Greg Kroah-Hartman2017-11-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby <jslaby@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: James Hogan <jhogan@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: "Uwe Kleine-König" <kernel@pengutronix.de> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: drop incorrect memsetArnd Bergmann2017-11-041-1/+0
| | | | | | | | | | | | | | | gcc points out that the length passed into memset here is wrong: drivers/tty/serial/mvebu-uart.c: In function 'mvebu_uart_probe': arch/x86/include/asm/string_32.h:324:29: error: 'memset' used with length equal to number of elements without multiplication by element size [-Werror=memset-elt-size] Moreover, the structure was allocated with kzalloc a few lines earlier, so that memset is also unnecessary. Let's drop it to shut up the compiler warning. Fixes: 95f787685a22 ("serial: mvebu-uart: dissociate RX and TX interrupts") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: support extended port registers layoutMiquel Raynal2017-10-201-0/+24
| | | | | | | | | | Define the missing register offsets and bit fields for the extended UART port. Add a second driver data structure filled with its port data, selected with the right compatible (marvell,armada-3700-uart-ext). Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com> Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: augment the maximum number of portsMiquel Raynal2017-10-201-1/+1
| | | | | | | | | A3700 boards may have up to two UART ports. Set the new limit to two maximum UART ports. Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com> Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: dissociate RX and TX interruptsMiquel Raynal2017-10-201-12/+119
| | | | | | | | | | | | | | | | | While the standard UART port can use a single IRQ that 'sums' both RX and TX interrupts, the extended port cannot and has to use two different ISR, one for each direction. The standard port also has the hability to use two separate interrupts (one for each direction). The logic is then: either there is only one unnamed interrupt on the standard port and this interrupt must be used for both directions (this is legacy bindings); or all the interrupts must be described and named 'uart-sum' (if available), 'uart-rx', 'uart-tx' and two separate handlers for each direction will be used. Suggested-by: Allen Yan <yanwei@marvell.com> Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: add TX interrupt trigger for pulse interruptsAllen Yan2017-10-201-1/+9
| | | | | | | | | | | | | Pulse interrupts (extended UART only) needs a change of state to trigger the TX interrupt. In addition to enabling the TX_READY_INT_EN flag, produce a FIFO state change from 'empty' to 'not full'. For this, write only one data byte in TX start, making the TX FIFO not empty, and wait for the TX interrupt to continue the transfer. Signed-off-by: Allen Yan <yanwei@marvell.com> Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com> Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: clear state register before IRQ requestAllen Yan2017-10-201-0/+6
| | | | | | | | | | | | | | | | When receiving data on RX pin before ->uart_startup() is called, some error bits in the state register could be set up (like BRK_DET). This is harmless when using only the standard UART (error bits are read-only), but may procude an endless loop once in the extended UART RX interrupt handler (error bits must be cleared). Clear the status register in ->uart_startup() to avoid this situation. Signed-off-by: Allen Yan <yanwei@marvell.com> Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com> Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: add function to change baudrateAllen Yan2017-10-201-4/+65
| | | | | | | | | | | | | | | | | | Until now, the first UART port baudrate was set by the bootloader. Add a function allowing to change the baudrate. Changes may be done from userspace but also at probe time by the kernel. Use the simplest method: baudrate divisor. Works for all UART ports until 230400 baud. To achieve higher baudrates, software should implement the fractional divisor feature that allows more accuracy for higher rates. Signed-off-by: Allen Yan <yanwei@marvell.com> [<miquel.raynal@free-electrons.com>: changed termios handling] Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com> Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: add soft reset at probeAllen Yan2017-10-201-0/+5
| | | | | | | | | | | | The existing UART driver relies on the bootloader to initialize the port(s). However, the secondary uart port may not be initialized properly in early boot stage. This patch adds the UART soft reset when probing, for all ports. Signed-off-by: Allen Yan <yanwei@marvell.com> Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com> Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: use a generic way to access the registersMiquel Raynal2017-10-201-73/+140
| | | | | | | | | | | | | | | | | | There are two UART ports on Armada3700. The second UART is based on the first one, plus additional features, but it has a different register layout (some bit fields are also moved inside the registers). Clearly separate register offsets and bit fields that differ between the standard and the extended IP. Access them in a generic way. Rename the defines with the "STD" prefix for future distinction with "EXT" defines. Point to these defines in the main driver data structure. The early console only uses the standard port (not extended). Suggested-by: Wilson Ding <dingwei@marvell.com> Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com> Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: support probe of multiple portsAllen Yan2017-10-201-3/+19
| | | | | | | | | | | | | | Until now, the mvebu-uart driver only supported probing a single UART port. However, some platforms have multiple instances of this UART controller, and therefore the driver should support multiple ports. In order to achieve this, we make sure to assign port->line properly, instead of hardcoding it to zero. Signed-off-by: Allen Yan <yanwei@marvell.com> Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com> Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: use driver name when requesting an interruptYehuda Yitschak2017-10-201-3/+4
| | | | | | | | | | | | Use the driver name when requesting an interrupt for consistency. Avoids possible confusion with DW8250 driver interrupt names in /proc/interrupts. Signed-off-by: Yehuda Yitschak <yehuday@marvell.com> Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com> Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: free the IRQ in ->shutdown()Thomas Petazzoni2016-06-251-0/+2
| | | | | | | | | | | | | | | | | | | As suggested by the serial port infrastructure documentation, the IRQ is requested in ->startup(). However, it is never freed in the ->shutdown() hook. With simple systems that open the serial port once for all and always have at least one process that keep the serial port opened, there was no problem. But with a more complicated system (*cough* systemd *cough*), the serial port is opened/closed many times, which at some point no processes having the serial port open at all. Due to this ->startup() gets called again, tries to request_irq() again, which fails. Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Cc: <stable@vger.kernel.org> Cc: Ofer Heifetz <oferh@marvell.com> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers/tty: make serial/mvebu-uart.c explicitly non-modularPaul Gortmaker2016-04-301-25/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Kconfig currently controlling compilation of this code is: drivers/tty/serial/Kconfig:config SERIAL_MVEBU_UART drivers/tty/serial/Kconfig: bool "Marvell EBU 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 the code wasn't using module_init to begin with, the init ordering remains unchanged with this commit. Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code. We also delete the MODULE_LICENSE tag etc. since all that information was (or is now) contained at the top of the file in the comments. Cc: Wilson Ding <dingwei@marvell.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: fix platform_no_drv_owner.cocci warningsJulia Lawall2016-04-301-1/+0
| | | | | | | | | | | No need to set .owner here. The core will do it. Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci CC: Wilson Ding <dingwei@marvell.com> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: mvebu-uart: initial support for Armada-3700 serial portWilson Ding2016-03-081-0/+650
Armada-3700's uart is a simple serial port, which doesn't support. Configuring the modem control lines. The uart port has a 32 bytes Tx FIFO and a 64 bytes Rx FIFO The uart driver implements the uart core operations. It also support the system (early) console based on Armada-3700's serial port. Known Issue: The uart driver currently doesn't support clock programming, which means the baud-rate stays with the default value configured by the bootloader at boot time [gregory.clement@free-electrons.com: Rewrite many part which are too long to enumerate] Signed-off-by: Wilson Ding <dingwei@marvell.com> Signed-off-by: Nadav Haklai <nadavh@marvell.com> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>