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2024-04-16serial: meson+qcom: don't advance the kfifo twiceJiri Slaby (SUSE)1-1/+0
Marek reports, that the -next commit 1788cf6a91d9 (tty: serial: switch from circ_buf to kfifo) broke meson_uart and qcom_geni_serial. The commit mistakenly advanced the kfifo twice: once by uart_fifo_get()/kfifo_out() and second time by uart_xmit_advance(). To advance the fifo only once, drop the superfluous uart_xmit_advance() from both. To count the TX statistics properly, use uart_fifo_out() in qcom_geni_serial (meson_uart_start_tx() already uses that). I checked all other uses of uart_xmit_advance() and they appear correct: either they are finishing DMA transfers or are after peek/linear_ptr (i.e. they do not advance fifo). Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Fixes: 1788cf6a91d9 ("tty: serial: switch from circ_buf to kfifo") Cc: Neil Armstrong <neil.armstrong@linaro.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Jerome Brunet <jbrunet@baylibre.com> Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Link: https://lore.kernel.org/r/20240416054825.6211-1-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09tty: serial: switch from circ_buf to kfifoJiri Slaby (SUSE)1-6/+5
Switch from struct circ_buf to proper kfifo. kfifo provides much better API, esp. when wrap-around of the buffer needs to be taken into account. Look at pl011_dma_tx_refill() or cpm_uart_tx_pump() changes for example. Kfifo API can also fill in scatter-gather DMA structures, so it easier for that use case too. Look at lpuart_dma_tx() for example. Note that not all drivers can be converted to that (like atmel_serial), they handle DMA specially. Note that usb-serial uses kfifo for TX for ages. omap needed a bit more care as it needs to put a char into FIFO to start the DMA transfer when OMAP_DMA_TX_KICK is set. In that case, we have to do kfifo_dma_out_prepare twice: once to find out the tx_size (to find out if it is worths to do DMA at all -- size >= 4), the second time for the actual transfer. All traces of circ_buf are removed from serial_core.h (and its struct uart_state). Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Al Cooper <alcooperx@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Cc: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com> Cc: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: Maciej W. Rozycki <macro@orcam.me.uk> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Neil Armstrong <neil.armstrong@linaro.org> 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: Bjorn Andersson <andersson@kernel.org> Cc: Konrad Dybcio <konrad.dybcio@linaro.org> Cc: Pali Rohár <pali@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Alim Akhtar <alim.akhtar@samsung.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Orson Zhai <orsonzhai@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.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: Hammer Hsieh <hammerh0314@gmail.com> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@kernel.org> Cc: Michal Simek <michal.simek@amd.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Link: https://lore.kernel.org/r/20240405060826.2521-13-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-03serial: meson: Use uart_prepare_sysrq_char().Sebastian Andrzej Siewior1-14/+8
The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT. The driver splits the locking function into two parts: local_irq_save() and uart_port_lock() and this breaks PREEMPT_RT. Delay handling sysrq until port lock is dropped. Remove the special case in the console write routine an always use the complete locking function. Cc: Kevin Hilman <khilman@baylibre.com> Cc: Jerome Brunet <jbrunet@baylibre.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-amlogic@lists.infradead.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://lore.kernel.org/r/20240301215246.891055-5-bigeasy@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-23serial: meson: Convert to platform remove callback returning voidUwe Kleine-König1-5/+3
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20231110152927.70601-24-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-17tty: serial: meson: fix hard LOCKUP on crtscts modePavel Krasavin1-3/+11
There might be hard lockup if we set crtscts mode on port without RTS/CTS configured: # stty -F /dev/ttyAML6 crtscts; echo 1 > /dev/ttyAML6; echo 2 > /dev/ttyAML6 [ 95.890386] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: [ 95.890857] rcu: 3-...0: (201 ticks this GP) idle=e33c/1/0x4000000000000000 softirq=5844/5846 fqs=4984 [ 95.900212] rcu: (detected by 2, t=21016 jiffies, g=7753, q=296 ncpus=4) [ 95.906972] Task dump for CPU 3: [ 95.910178] task:bash state:R running task stack:0 pid:205 ppid:1 flags:0x00000202 [ 95.920059] Call trace: [ 95.922485] __switch_to+0xe4/0x168 [ 95.925951] 0xffffff8003477508 [ 95.974379] watchdog: Watchdog detected hard LOCKUP on cpu 3 [ 95.974424] Modules linked in: 88x2cs(O) rtc_meson_vrtc Possible solution would be to not allow to setup crtscts on such port. Tested on S905X3 based board. Fixes: ff7693d079e5 ("ARM: meson: serial: add MesonX SoC on-chip uart driver") Cc: stable@vger.kernel.org Signed-off-by: Pavel Krasavin <pkrasavin@imaqliq.com> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Reviewed-by: Dmitry Rokosov <ddrokosov@salutedevices.com> v6: stable tag added v5: https://lore.kernel.org/lkml/OF43DA36FF.2BD3BB21-ON00258A47.005A8125-00258A47.005A9513@gdc.ru/ added missed Reviewed-by tags, Fixes tag added according to Dmitry and Neil notes v4: https://lore.kernel.org/lkml/OF55521400.7512350F-ON00258A47.003F7254-00258A47.0040E15C@gdc.ru/ More correct patch subject according to Jiri's note v3: https://lore.kernel.org/lkml/OF6CF5FFA0.CCFD0E8E-ON00258A46.00549EDF-00258A46.0054BB62@gdc.ru/ "From:" line added to the mail v2: https://lore.kernel.org/lkml/OF950BEF72.7F425944-ON00258A46.00488A76-00258A46.00497D44@gdc.ru/ braces for single statement removed according to Dmitry's note v1: https://lore.kernel.org/lkml/OF28B2B8C9.5BC0CD28-ON00258A46.0037688F-00258A46.0039155B@gdc.ru/ Link: https://lore.kernel.org/r/OF66360032.51C36182-ON00258A48.003F656B-00258A48.0040092C@gdc.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-10tty: serial: meson: Add a earlycon for the S4 SoCLucas Tanure1-2/+2
The new Amlogic S4 SoC does not have a always-on uart, so add OF_EARLYCON_DECLARE for it. Amlogic T7 will use this as fallback. Signed-off-by: Lucas Tanure <tanure@linux.com> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Link: https://lore.kernel.org/r/20231009121151.4509-1-tanure@linux.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-18serial: meson: Use port lock wrappersThomas Gleixner1-15/+15
When a serial port is used for kernel console output, then all modifications to the UART registers which are done from other contexts, e.g. getty, termios, are interference points for the kernel console. So far this has been ignored and the printk output is based on the principle of hope. The rework of the console infrastructure which aims to support threaded and atomic consoles, requires to mark sections which modify the UART registers as unsafe. This allows the atomic write function to make informed decisions and eventually to restore operational state. It also allows to prevent the regular UART code from modifying UART registers while printk output is in progress. All modifications of UART registers are guarded by the UART port lock, which provides an obvious synchronization point with the console infrastructure. To avoid adding this functionality to all UART drivers, wrap the spin_[un]lock*() invocations for uart_port::lock into helper functions which just contain the spin_[un]lock*() invocations for now. In a subsequent step these helpers will gain the console synchronization mechanisms. Converted with coccinelle. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Neil Armstrong <neil.armstrong@linaro.org> Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20230914183831.587273-38-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-27Revert "tty: serial: meson: Add a earlycon for the T7 SoC"Lucas Tanure1-2/+0
This reverts commit 6a4197f9763325043abf7690a21124a9facbf52e New SoC will use ttyS0 instead of ttyAML, so T7 SoC doesn't need a OF_EARLYCON_DECLARE. Fixes: 6a4197f97633 ("tty: serial: meson: Add a earlycon for the T7 SoC") Signed-off-by: Lucas Tanure <tanure@linux.com> Link: https://lore.kernel.org/r/20230827082944.5100-1-tanure@linux.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-22tty: serial: meson: Add a earlycon for the T7 SoCLucas Tanure1-0/+2
The new Amlogic T7 SoC does not have a always-on uart, so add OF_EARLYCON_DECLARE for it. Signed-off-by: Lucas Tanure <tanure@linux.com> Acked-by: Neil Armstrong <neil.armstrong@linaro.org> Link: https://lore.kernel.org/r/20230814080128.143613-2-tanure@linux.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-30tty: serial: meson: refactor objects definition for different devnamesDmitry Rokosov1-23/+16
Macroses for name generation are not useful. They hide the real place for object declaration. Instead, use direct names such as 'meson_uart_driver_*' and 'meson_serial_console_*' for all objects. Additionally, rename 'MESON_SERIAL_CONSOLE_DEFINE()' to 'MESON_SERIAL_CONSOLE()', and 'MESON_UART_DRIVER_DEFINE()' to 'MESON_UART_DRIVER()' to simplify the code. Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> Suggested-by: Neil Armstrong <neil.armstrong@linaro.org> Link: https://lore.kernel.org/r/20230728071522.17503-1-ddrokosov@sberdevices.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-25tty: serial: meson: add independent uart_data for A1 SoC familyDmitry Rokosov1-0/+9
Implement separate uart_data to ensure proper devname value for the A1 SoC family. Use 'ttyS' devname, as required by the A1 architecture, instead of the legacy gx architecture. Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Link: https://lore.kernel.org/r/20230705181833.16137-6-ddrokosov@sberdevices.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-25tty: serial: meson: introduce separate uart_data for S4 SoC familyDmitry Rokosov1-1/+6
In order to use the correct devname value for the S4 SoC family, it is imperative that we implement separate uart_data. Unlike the legacy g12a architecture, the S4 architecture should employ the use of 'ttyS' devname. Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Link: https://lore.kernel.org/r/20230705181833.16137-5-ddrokosov@sberdevices.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-25tty: serial: meson: apply ttyS devname instead of ttyAML for new SoCsDmitry Rokosov1-26/+56
It is worth noting that the devname ttyS is a widely recognized tty name and is commonly used by many uart device drivers. Given the established usage and compatibility concerns, it may not be feasible to change the devname for older SoCs. However, for new definitions, it is acceptable and even recommended to use a new devname to help ensure clarity and avoid any potential conflicts on lower or upper software levels. For more information please refer to IRC discussion at [1]. Links: [1]: https://libera.irclog.whitequark.org/linux-amlogic/2023-07-03 Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> Link: https://lore.kernel.org/r/20230705181833.16137-4-ddrokosov@sberdevices.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-25tty: serial: meson: redesign the module to platform_driverDmitry Rokosov1-36/+15
Actually, the meson_uart module is already a platform_driver, but it is currently registered manually and the uart core registration is run outside the probe() scope, which results in some restrictions. For instance, it is not possible to communicate with the OF subsystem because it requires an initialized device object. To address this issue, apply module_platform_driver() instead of direct module init/exit routines. Additionally, move uart_register_driver() to the driver probe(), and destroy manual console registration because it's already run in the uart_register_driver() flow. Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Link: https://lore.kernel.org/r/20230705181833.16137-3-ddrokosov@sberdevices.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-25tty: serial: meson: use dev_err_probeDmitry Rokosov1-2/+2
Use dev_err_probe() helper for error checking and standard logging. It makes the driver's probe() function a little bit shorter. Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Link: https://lore.kernel.org/r/20230705181833.16137-2-ddrokosov@sberdevices.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09tty: serial: meson: Add a new compatible string for the G12A SoCMartin Blumenstingl1-2/+6
Amlogic Meson G12A (and later) SoCs also have the "divide XTAL by 2" bit as the S4 UART controllers. Add a new compatible string for these SoCs and enable the has_xtal_div2 flag for them. Tested-by: Christian Hewitt <christianshewitt@gmail.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Link: https://lore.kernel.org/r/20230307222651.2106615-3-martin.blumenstingl@googlemail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: meson: Use uart_xmit_advance()Ilpo Järvinen1-2/+1
Take advantage of the new uart_xmit_advance() helper. Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Neil Armstrong <neil.armstrong@linaro.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-23-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30serial: Make ->set_termios() old ktermios constIlpo Järvinen1-1/+1
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>
2022-08-30tty: serial: meson: Use devm_clk_get_enabled() helperChristophe JAILLET1-26/+3
The devm_clk_get_enabled() helper: - calls devm_clk_get() - calls clk_prepare_enable() and registers what is needed in order to call clk_disable_unprepare() when needed, as a managed resource. This simplifies the code, the error handling paths and avoid the need of a dedicated function used with devm_add_action_or_reset(). That said, meson_uart_probe_clock() is now more or less the same as devm_clk_get_enabled(), so use this function directly instead. This also fixes an (unlikely) unchecked devm_add_action_or_reset() error. Based on my test with allyesconfig, this reduces the .o size from: text data bss dec hex filename 16350 5016 128 21494 53f6 drivers/tty/serial/meson_uart.o down to: 15415 4784 128 20327 4f67 drivers/tty/serial/meson_uart.o Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Link: https://lore.kernel.org/r/3f18638cb3cf08ed8817addca1402ed5e3bd3602.1661328361.git.christophe.jaillet@wanadoo.fr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27serial: Convert SERIAL_XMIT_SIZE to UART_XMIT_SIZEIlpo Järvinen1-1/+1
Both UART_XMIT_SIZE and SERIAL_XMIT_SIZE are defined. Make them all UART_XMIT_SIZE. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220624205424.12686-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-19serial: meson: acquire port->lock in startup()John Ogness1-0/+13
The uart_ops startup() callback is called without interrupts disabled and without port->lock locked, relatively late during the boot process (from the call path of console_on_rootfs()). If the device is a console, it was already previously registered and could be actively printing messages. Since the startup() callback is reading/writing registers used by the console write() callback (AML_UART_CONTROL), its access must be synchronized using the port->lock. Currently it is not. The startup() callback is the only function that explicitly enables interrupts. Without the synchronization, it is possible that interrupts become accidentally permanently disabled. CPU0 CPU1 meson_serial_console_write meson_uart_startup -------------------------- ------------------ spin_lock(port->lock) val = readl(AML_UART_CONTROL) uart_console_write() writel(INT_EN, AML_UART_CONTROL) writel(val, AML_UART_CONTROL) spin_unlock(port->lock) Add port->lock synchronization to meson_uart_startup() to avoid racing with meson_serial_console_write(). Also add detailed comments to meson_uart_reset() explaining why it is *not* using port->lock synchronization. Link: https://lore.kernel.org/lkml/2a82eae7-a256-f70c-fd82-4e510750906e@samsung.com Fixes: ff7693d079e5 ("ARM: meson: serial: add MesonX SoC on-chip uart driver") Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20220508103547.626355-1-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: serial: meson: Added S4 SOC compatibilityYu Tu1-0/+8
Make UART driver compatible with S4 SOC UART. Meanwhile, the S4 SOC UART uses 12MHz as the clock source for baud rate calculations. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Yu Tu <yu.tu@amlogic.com> Link: https://lore.kernel.org/r/20220422111320.19234-3-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: serial: meson: Add a 12MHz internal clock rate to calculate baud rate ↵Yu Tu1-2/+15
in order to meet the baud rate requirements of special BT modules A /2 divider over XTAL was introduced since G12A, and is preferred to be used over the still present /3 divider since it provides much closer frequencies vs the request baudrate. Especially the BT module uses 3Mhz baud rate. 8Mhz calculations can lead to baud rate bias, causing some problems. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Yu Tu <yu.tu@amlogic.com> Link: https://lore.kernel.org/r/20220422111320.19234-2-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-15tty: serial: meson: Use DIV_ROUND_CLOSEST to calculate baud ratesYu Tu1-2/+2
Due to chip process differences, chip designers recommend using baud rates as close to and larger as possible in order to reduce clock errors. Signed-off-by: Yu Tu <yu.tu@amlogic.com> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Link: https://lore.kernel.org/r/20220407081355.13602-2-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-03serial: make uart_console_write->putchar()'s character an unsigned charJiri Slaby1-1/+1
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>
2022-03-02Revert "tty: serial: meson: *"Greg Kroah-Hartman1-154/+67
This reverts the following commits: 31979060cc07 tty: serial: meson: Fix the compile link error reported by kernel test robot 5427c352a993 tty: serial: meson: Added S4 SOC compatibility 19b2ba0baffc tty: serial: meson: The system stuck when you run the stty command on the console to change the baud rate e5fc2b99840d tty: serial: meson: Make some bit of the REG5 register writable 44023b8e1f14 tty: serial: meson: Describes the calculation of the UART baud rate clock using a clock frame 6436dd8f9b25 tty: serial: meson: Use devm_ioremap_resource to get register mapped memory 841f913e770f tty: serial: meson: Move request the register region to probe They seem to cause lots of problems with existing hardware platforms, and caused build issues, so revert the whole series all at once. Link: https://lore.kernel.org/r/849a95fd-ae81-9a3b-0c06-dd7826af9eb2@baylibre.com Link: https://lore.kernel.org/all/20220225073922.3947-1-yu.tu@amlogic.com/ Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Reported-by: Jerome Brunet <jbrunet@baylibre.com> Cc: Neil Armstrong <narmstrong@baylibre.com> Cc: Yu Tu <yu.tu@amlogic.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-26tty: serial: meson: Added S4 SOC compatibilityYu Tu1-0/+4
Make UART driver compatible with S4 SOC UART. Signed-off-by: Yu Tu <yu.tu@amlogic.com> Link: https://lore.kernel.org/r/20220225073922.3947-7-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-26tty: serial: meson: The system stuck when you run the stty command on the ↵Yu Tu1-0/+5
console to change the baud rate Start the console and run the following commands in turn: stty -F /dev/ttyAML0 115200 and stty -F /dev/ttyAML0 921600. The system will stuck. Signed-off-by: Yu Tu <yu.tu@amlogic.com> Link: https://lore.kernel.org/r/20220225073922.3947-6-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-26tty: serial: meson: Make some bit of the REG5 register writableYu Tu1-2/+2
Make the internal clock source mux and divider writeable, allowing the uart to deviate from the settings intially applied by the ROMCode and using the most appropriate clocks. Signed-off-by: Yu Tu <yu.tu@amlogic.com> Link: https://lore.kernel.org/r/20220225073922.3947-5-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-26tty: serial: meson: Describes the calculation of the UART baud rate clock ↵Yu Tu1-52/+142
using a clock frame Using the common Clock code to describe the UART baud rate clock makes it easier for the UART driver to be compatible with the baud rate requirements of the UART IP on different meson chips. Signed-off-by: Yu Tu <yu.tu@amlogic.com> Link: https://lore.kernel.org/r/20220225073922.3947-4-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-26tty: serial: meson: Use devm_ioremap_resource to get register mapped memoryYu Tu1-9/+1
Replace devm_request_mem_region and devm_ioremap with devm_ioremap_resource to make the code cleaner. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Yu Tu <yu.tu@amlogic.com> Link: https://lore.kernel.org/r/20220225073922.3947-3-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-26tty: serial: meson: Move request the register region to probeYu Tu1-18/+14
This simplifies resetting the UART controller during probe and will make it easier to integrate the common clock code which will require the registers at probe time as well. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Yu Tu <yu.tu@amlogic.com> Link: https://lore.kernel.org/r/20220225073922.3947-2-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30tty: serial: meson: Drop the legacy compatible strings and clock codeYu Tu1-32/+2
All mainline .dts files have been using the stable UART since Linux 4.16. Drop the legacy compatible strings and related clock code. Signed-off-by: Yu Tu <yu.tu@amlogic.com> Link: https://lore.kernel.org/r/20211230102110.3861-2-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30serial: meson: Use platform_get_irq() to get the interruptLad Prabhakar1-5/+6
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static allocation of IRQ resources in DT core code, this causes an issue when using hierarchical interrupt domains using "interrupts" property in the node as this bypasses the hierarchical setup and messes up the irq chaining. In preparation for removal of static setup of IRQ resource from DT core code use platform_get_irq(). Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20211224142917.6966-5-prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20tty: serial: meson: retrieve port FIFO size from DTNeil Armstrong1-1/+4
Now the DT bindings has a property to get the FIFO size for a particular port, retrieve it and use to setup the FIFO interrupts threshold. Reviewed-by: Kevin Hilman <khilman@baylibre.com> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Link: https://lore.kernel.org/r/20210518075833.3736038-3-narmstrong@baylibre.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13serial: meson: remove redundant initialization of variable idColin Ian King1-1/+2
The variable id being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Since id is just being used in a for-loop inside a local scope, move the declaration of id to that scope. Reviewed-by: Kevin Hilman <khilman@baylibre.com> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> Addresses-Coverity: ("Unused value") Link: https://lore.kernel.org/r/20210426101106.9122-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: meson: drop low-latency workaroundJohan Hovold1-2/+0
The meson driver has always carried an unnecessary workaround for the infamous low_latency behaviour of tty_flip_buffer_push(), which had already been removed by the time the driver was added by commit ff7693d079e5 ("ARM: meson: serial: add MesonX SoC on-chip uart driver"). Specifically, since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-15-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-11tty: serial: meson: enable console as moduleKevin Hilman1-1/+7
Enable serial driver to be built as a module. To do so, init the console support on driver/module load instead of using console_initcall(). Signed-off-by: Kevin Hilman <khilman@baylibre.com> Link: https://lore.kernel.org/r/20201211005744.12855-1-khilman@baylibre.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-29Merge tag 'tty-5.6-rc1' of ↵Linus Torvalds1-4/+66
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here are the big set of tty and serial driver updates for 5.6-rc1 Included in here are: - dummy_con cleanups (touches lots of arch code) - sysrq logic cleanups (touches lots of serial drivers) - samsung driver fixes (wasn't really being built) - conmakeshash move to tty subdir out of scripts - lots of small tty/serial driver updates All of these have been in linux-next for a while with no reported issues" * tag 'tty-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (140 commits) tty: n_hdlc: Use flexible-array member and struct_size() helper tty: baudrate: SPARC supports few more baud rates tty: baudrate: Synchronise baud_table[] and baud_bits[] tty: serial: meson_uart: Add support for kernel debugger serial: imx: fix a race condition in receive path serial: 8250_bcm2835aux: Document struct bcm2835aux_data serial: 8250_bcm2835aux: Use generic remapping code serial: 8250_bcm2835aux: Allocate uart_8250_port on stack serial: 8250_bcm2835aux: Suppress register_port error on -EPROBE_DEFER serial: 8250_bcm2835aux: Suppress clk_get error on -EPROBE_DEFER serial: 8250_bcm2835aux: Fix line mismatch on driver unbind serial_core: Remove unused member in uart_port vt: Correct comment documenting do_take_over_console() vt: Delete comment referencing non-existent unbind_con_driver() arch/xtensa/setup: Drop dummy_con initialization arch/x86/setup: Drop dummy_con initialization arch/unicore32/setup: Drop dummy_con initialization arch/sparc/setup: Drop dummy_con initialization arch/sh/setup: Drop dummy_con initialization arch/s390/setup: Drop dummy_con initialization ...
2020-01-22tty: serial: meson_uart: Add support for kernel debuggerJulien Masson1-0/+65
The kgdb invokes the poll_put_char and poll_get_char when communicating with the host. This patch implement the serial polling hooks for the meson_uart to be used for KGDB debugging over serial line. Signed-off-by: Julien Masson <jmasson@baylibre.com> Link: https://lore.kernel.org/r/867e1klo48.fsf@julienm-fedora-R90NQGV9.i-did-not-set--mail-host-address--so-tickle-me Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-06remove ioremap_nocache and devm_ioremap_nocacheChristoph Hellwig1-1/+1
ioremap has provided non-cached semantics by default since the Linux 2.6 days, so remove the additional ioremap_nocache interface. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Arnd Bergmann <arnd@arndb.de>
2019-12-18tty/serial: Migrate meson_uart to use has_sysrqDmitry Safonov1-4/+1
The SUPPORT_SYSRQ ifdeffery is not nice as: - May create misunderstanding about sizeof(struct uart_port) between different objects - Prevents moving functions from serial_core.h - Reduces readability (well, it's ifdeffery - it's hard to follow) In order to remove SUPPORT_SYSRQ, has_sysrq variable has been added. Initialise it in driver's probe and remove ifdeffery. Cc: Kevin Hilman <khilman@baylibre.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-amlogic@lists.infradead.org Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://lore.kernel.org/r/20191213000657.931618-22-dima@arista.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18tty: serial: meson: if no alias specified use an available idLoys Ollivier1-1/+12
At probe, the uart driver tries to get an id from a device tree alias. When no alias was specified, the driver would return an error and probing would fail. Providing an alias for registering a serial device should not be mandatory. If the device tree does not specify an alias, provide an id from a reserved range so that the probing can continue. Suggested-by: Rob Herring <robh@kernel.org> Signed-off-by: Loys Ollivier <lollivier@baylibre.com> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28tty: serial: meson: fix typo in the "stop bit" register definitionMartin Blumenstingl1-6/+6
This simply fixes a typo in the preprocessor macros. No functional changes intended. Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28tty: serial: meson: merge the two register sections for AML_UART_CONTROLMartin Blumenstingl1-9/+7
In the code there are two separate sections which each describe some of the bits in the AML_UART_CONTROL register. Merge these into one section to make the code easier to read. No functional changes intended. Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28tty: serial: meson: remove duplicate "clear error" bit definitionMartin Blumenstingl1-5/+4
The "clear error" bit in the AML_UART_CONTROL register is defined twice. Remove the AML_UART_CLR_ERR definition and replace it with AML_UART_CLEAR_ERR. AML_UART_CLEAR_ERR was chosen to be kept since the datasheet's description for this bit is "Clear Error" (so developer's don't have to translate this to "CLR_ERR"). No functional changes intended. Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-08tty: serial: meson: allow baud-rates lower than 9600Thomas Rohloff1-1/+1
Devices like DCF77 receivers need the baud-rate to be as low as 50. I have tested this on a Meson GXL device with uart_A. Cc: Jiri Slaby <jslaby@suse.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: linux-amlogic@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Thomas Rohloff <v10lator@myway.de> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-08tty: serial: Remove redundant license textGreg Kroah-Hartman1-10/+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>
2017-11-08tty: add SPDX identifiers to all remaining files in drivers/tty/Greg Kroah-Hartman1-0/+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>
2017-09-18serial: meson: add Magic SysRq supportYixun Lan1-2/+16
This dirver try to implement the Magic SysRq support[1] for Amlogic Inc's meson platfo >From the hardware perspective, the UART IP can't detect the 'BREAK' command clearly via the status register. Instead, we rely on the combination of 'FRAME_ERR bit && ch == 0', and it works fine. [1] Documentation/admin-guide/sysrq.rst Signed-off-by: Yixun Lan <dlan@gentoo.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>