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* Merge 6.9-rc5 into tty-nextGreg Kroah-Hartman2024-04-231-2/+11
|\ | | | | | | | | | | | | | | | | We want the tty fixes in here as well, and it resolves a merge conflict in: drivers/tty/serial/serial_core.c as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: stm32: Reset .throttled state in .startup()Uwe Kleine-König2024-04-171-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When an UART is opened that still has .throttled set from a previous open, the RX interrupt is enabled but the irq handler doesn't consider it. This easily results in a stuck irq with the effect to occupy the CPU in a tight loop. So reset the throttle state in .startup() to ensure that RX irqs are handled. Fixes: d1ec8a2eabe9 ("serial: stm32: update throttle and unthrottle ops for dma mode") Cc: stable@vger.kernel.org Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/a784f80d3414f7db723b2ec66efc56e1ad666cbf.1713344161.git.u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: stm32: Return IRQ_NONE in the ISR if no handling happendUwe Kleine-König2024-04-171-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If there is a stuck irq that the handler doesn't address, returning IRQ_HANDLED unconditionally makes it impossible for the irq core to detect the problem and disable the irq. So only return IRQ_HANDLED if an event was handled. A stuck irq is still problematic, but with this change at least it only makes the UART nonfunctional instead of occupying the (usually only) CPU by 100% and so stall the whole machine. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Cc: stable@vger.kernel.org Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/5f92603d0dfd8a5b8014b2b10a902d91e0bb881f.1713344161.git.u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | tty: serial: switch from circ_buf to kfifoJiri Slaby (SUSE)2024-04-091-32/+20
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge 6.8-rc6 into tty-nextGreg Kroah-Hartman2024-02-271-1/+3
|\ | | | | | | | | | | We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: stm32: do not always set SER_RS485_RX_DURING_TX if RS485 is enabledLino Sanfilippo2024-02-191-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before commit 07c30ea5861f ("serial: Do not hold the port lock when setting rx-during-tx GPIO") the SER_RS485_RX_DURING_TX flag was only set if the rx-during-tx mode was not controlled by a GPIO. Now the flag is set unconditionally when RS485 is enabled. This results in an incorrect setting if the rx-during-tx GPIO is not asserted. Fix this by setting the flag only if the rx-during-tx mode is not controlled by a GPIO and thus restore the correct behaviour. Cc: stable@vger.kernel.org # 6.6+ Fixes: 07c30ea5861f ("serial: Do not hold the port lock when setting rx-during-tx GPIO") Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240216224709.9928-1-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: stm32: get FIFO size from hwcfg registerValentin Caron2024-01-271-69/+89
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Since STM32MP25, FIFO size could vary regarding the STM32MPxx version. So we get this size from "hwcfgr1" register and compute threshold values corresponding to the ratio given by reference manual. As STM32MP1x, STM32MP25 and STM32H7 share the same compatible and STM32H7 doesn't have a register to get FIFO size, we force FIFO size to 16 in case of zero read from hwcfgr1 register. Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20240112095300.2004878-5-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: stm32: implement prescaler tuning to compute low baudrateValentin Caron2024-01-271-21/+50
|/ | | | | | | | | | | | In the case of high USART input clock and low baud rate, BRR value is not enough to get correct baud rate. So here we use USART prescaler to divide USART input clock to get the correct baud rate. PRESC register is only available since stm32h7. Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20240112095300.2004878-2-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Do not hold the port lock when setting rx-during-tx GPIOLino Sanfilippo2024-01-041-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Both the imx and stm32 driver set the rx-during-tx GPIO in rs485_config(). Since this function is called with the port lock held, this can be a problem in case that setting the GPIO line can sleep (e.g. if a GPIO expander is used which is connected via SPI or I2C). Avoid this issue by moving the GPIO setting outside of the port lock into the serial core and thus making it a generic feature. Also with commit c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") the SER_RS485_RX_DURING_TX flag is only set if a rx-during-tx GPIO is _not_ available, which is wrong. Fix this, too. Furthermore reset old GPIO settings in case that changing the RS485 configuration failed. Fixes: c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") Fixes: ca530cfa968c ("serial: imx: Add support for RS485 RX_DURING_TX output GPIO") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-2-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: Convert to platform remove callback returning voidUwe Kleine-König2023-11-231-4/+2
| | | | | | | | | | | | | | | | | | | 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/20231110152927.70601-43-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: Use port lock wrappersThomas Gleixner2023-09-181-19/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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> Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20230914183831.587273-65-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: add support for break controlErwan Le Ray2023-09-181-1/+12
| | | | | | | | | | Add support for break control to the stm32 serial driver. Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230906151547.840302-1-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: synchronize RX DMA channel in shutdownAmelie Delaunay2023-08-221-1/+3
| | | | | | | | | | | | | In shutdown, RX DMA channel is terminated. If the DMA RX callback is scheduled but not yet executed, while a new RX DMA transfer is started, the callback can be executed, and then disturb the ongoing RX DMA transfer. To avoid such a case, call dmaengine_synchronize in shutdown, after the DMA RX channel is terminated. Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20230808161906.178996-7-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: replace access to DMAR bit by dmaengine_pause/resumeValentin Caron2023-08-221-94/+106
| | | | | | | | | | | | | | | | | | | | | | It's rather advised to rely on DMA pause / resume instead of clearing/setting DMA request enable bit for the same purpose. Some DMA request/acknowledge race may encountered by doing so. We prefer to use dmaengine_pause and resume instead to pause a dma transfer when it is necessary. Create two new functions (stm32_usart_rx_dma_pause, stm32_usart_rx_dma _resume) to handle dma error when pausing/resuming. And rename stm32_usart_start_rx_dma_cyclic() to stm32_usart_rx_dma_start_or_resume() and use this function to resume an rx dma transfer. If resume fail, stm32_usart_rx_dma_start_or_resume can create a new transfer to continue. It is also safer to close DMA before reset DMAR in stm32_usart_shutdown. Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20230808161906.178996-6-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: group dma pause/resume error handling into single functionValentin Caron2023-08-221-45/+82
| | | | | | | | | | | | | Create new function "stm32_usart_dma_pause_resume" that called dmaengine_ pause/resume and in case of error, terminate dma transaction. Two other functions are created to facilitate the use of stm32_usart_dma _pause_resume : stm32_usart_tx_dma_pause, stm32_usart_tx_dma_resume. Equivalent functions for rx will be added in future patch. Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20230808161906.178996-5-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: modify parameter and rename stm32_usart_rx_dma_enabledValentin Caron2023-08-221-8/+8
| | | | | | | | | | | | Rename stm32_usart_rx_dma_enabled to stm32_usart_rx_dma_started in order to match with stm32_usart_tx_dma_started. Modify argument of stm32_usart_rx_dma_started from uart_port structure to stm32_port structure to match with stm32_usart_tx_dma_started. Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20230808161906.178996-4-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: use DMAT as a configuration bitValentin Caron2023-08-221-5/+3
| | | | | | | | | | | | DMAT is a configuration bit so it should be set at the startup of uart port and not when a DMA transfer begins. This patch move set of DMAT into set_termios and remove DMAT reset except in shutdown. Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20230808161906.178996-3-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: avoid clearing DMAT bit during transferValentin Caron2023-08-221-32/+44
| | | | | | | | | | | | | | It's rather advised to rely on DMA pause / resume instead of clearing/setting DMA request enable bit for the same purpose. Some DMA request/acknowledge race may encountered by doing so. We prefer to use dmaengine_pause and resume instead to pause a dma transfer when it is necessary. It is also safer to close DMA before reset DMAT in stm32_usart_shutdown. Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20230808161906.178996-2-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: drivers: switch ch and flag to u8Jiri Slaby2023-07-251-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the serial layer explicitly expects 'u8' for flags and characters, propagate this type to drivers' (RX) routines. Note that amba-pl011's, clps711x's and st-asc's 'ch' are left unchanged because 'ch' contains not only a character, but whole status. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Tobias Klauser <tklauser@distanz.ch> 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@microchip.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@orcam.me.uk> Cc: Taichi Sugaya <sugaya.taichi@socionext.com> Cc: Takao Orito <orito.takao@socionext.com> 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: Kevin Cernekee <cernekee@gmail.com> 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: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.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: Hammer Hsieh <hammerh0314@gmail.com> Acked-by: Richard GENOUD <richard.genoud@gmail.com> Acked-by: Tobias Klauser <tklauser@distanz.ch> Acked-by: Thierry Reding <treding@nvidia.com> Acked-by: Maciej W. Rozycki <macro@orcam.me.uk> Link: https://lore.kernel.org/r/20230712081811.29004-11-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: Ignore return value of uart_remove_one_port() in .remove()Uwe Kleine-König2023-05-131-4/+1
| | | | | | | | | | | | | | | | | | | Returning early from stm32_usart_serial_remove() results in a resource leak as several cleanup functions are not called. The driver core ignores the return value and there is no possibility to clean up later. uart_remove_one_port() only returns non-zero if there is some inconsistency (i.e. stm32_usart_driver.state[port->line].uart_port == NULL). This should never happen, and even if it does it's a bad idea to exit early in the remove callback without cleaning up. This prepares changing the prototype of struct platform_driver::remove to return void. See commit 5c5a7680e67b ("platform: Provide a remove callback that returns no value") for further details about this quest. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20230512173810.131447-2-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: Re-assert RTS/DE GPIO in RS485 mode only if more data are ↵Marek Vasut2023-03-091-2/+3
| | | | | | | | | | | | | | | | | | | | | | transmitted The stm32_usart_transmit_chars() may be called with empty or stopped transmit queue, and no XON/OFF character pending. This can happen at the end of transmission, where this last call is used to either handle the XON/XOFF x_char, or disable TX interrupt if queue is empty or stopped. If that occurs, do not assert the RS485 RTS/DE GPIO anymore, as the GPIO would remain asserted past the end of transmission and that would block the RS485 bus after the transmission. Only assert the RS485 RTS/DE GPIO if there is either pending XON/XOFF x_char, or at least one character in running transmit queue. Fixes: d7c76716169d ("serial: stm32: Use TC interrupt to deassert GPIO RTS in RS485 mode") Signed-off-by: Marek Vasut <marex@denx.de> Link: https://lore.kernel.org/r/20230223042252.95480-2-marex@denx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: Remove unused struct stm32_port txdone elementMarek Vasut2023-03-091-1/+0
| | | | | | | | The txdone element is only ever assigned, once, and never used. Drop it. Signed-off-by: Marek Vasut <marex@denx.de> Link: https://lore.kernel.org/r/20230223042252.95480-1-marex@denx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge 6.2-rc7 into tty-nextGreg Kroah-Hartman2023-02-061-28/+5
|\ | | | | | | | | | | We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handlerMarek Vasut2023-01-311-28/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Requesting an interrupt with IRQF_ONESHOT will run the primary handler in the hard-IRQ context even in the force-threaded mode. The force-threaded mode is used by PREEMPT_RT in order to avoid acquiring sleeping locks (spinlock_t) in hard-IRQ context. This combination makes it impossible and leads to "sleeping while atomic" warnings. Use one interrupt handler for both handlers (primary and secondary) and drop the IRQF_ONESHOT flag which is not needed. Fixes: e359b4411c283 ("serial: stm32: fix threaded interrupt handling") Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Valentin Caron <valentin.caron@foss.st.com> # V3 Signed-off-by: Marek Vasut <marex@denx.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230120160332.57930-1-marex@denx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: stm32: Add support for rs485 RX_DURING_TX output GPIOChristoph Niedermaier2023-01-191-1/+5
|/ | | | | | | | | | | If a RX_DURING_TX GPIO is defined by the DT property "rs485-rx-during-tx-gpios" this patch switches this GPIO accordingly to the RS485 flag RX_DURING_TX in user space. Controlled by this GPIO, now the hardware is responsible for connecting or disconnecting RX during TX. Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com> Link: https://lore.kernel.org/r/20221202104127.122761-4-cniedermaier@dh-electronics.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: move dma_request_chan() before clk_prepare_enable()Valentin Caron2022-11-221-24/+23
| | | | | | | | | | | | | | | | If dma_request_chan() returns a PROBE_DEFER error, clk_disable_unprepare() will be called and USART clock will be disabled. But early console can be still active on the same USART. While moving dma_request_chan() before clk_prepare_enable(), the clock won't be taken in case of a DMA PROBE_DEFER error, and so it doesn't need to be disabled. Then USART is still clocked for early console. Fixes: a7770a4bfcf4 ("serial: stm32: defer probe for dma devices") Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20221118170602.1057863-1-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: Use uart_xmit_advance()Ilpo Järvinen2022-11-031-4/+3
| | | | | | | | Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-35-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: Fix unused-variable warningRen Zhijie2022-09-301-3/+3
| | | | | | | | | | | | | | | | | | | | | | | If CONFIG_SERIAL_EARLYCON and CONFIG_OF are both not set, gcc warns about unused variable: drivers/tty/serial/stm32-usart.c:83:32: error: ‘stm32h7_info’ defined but not used [-Werror=unused-variable] static struct stm32_usart_info stm32h7_info = { ^~~~~~~~~~~~ drivers/tty/serial/stm32-usart.c:61:32: error: ‘stm32f7_info’ defined but not used [-Werror=unused-variable] static struct stm32_usart_info stm32f7_info = { ^~~~~~~~~~~~ drivers/tty/serial/stm32-usart.c:40:32: error: ‘stm32f4_info’ defined but not used [-Werror=unused-variable] static struct stm32_usart_info stm32f4_info = { ^~~~~~~~~~~~ cc1: all warnings being treated as errors Mark these variables as __maybe_unused to fix this. Fixes: c7039ce904c0 ("serial: stm32: make info structs static to avoid sparse warnings") Signed-off-by: Ren Zhijie <renzhijie2@huawei.com> Link: https://lore.kernel.org/r/20220926025826.44145-1-renzhijie2@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: Deassert Transmit Enable on ->rs485_config()Lukas Wunner2022-09-221-47/+53
| | | | | | | | | | | | | | | | | | | | | | | The STM32 USART can control RS-485 Transmit Enable in hardware. Since commit 7df5081cbf5e ("serial: stm32: Add RS485 RTS GPIO control"), it can alternatively be controlled in software. That was done to allow RS-485 even if the RTS pin is unavailable because it's pinmuxed to a different function. However the commit neglected to deassert Transmit Enable upon invocation of the ->rs485_config() callback. Fix it. Avoid forward declarations by moving stm32_usart_tx_empty(), stm32_usart_rs485_rts_enable() and stm32_usart_rs485_rts_disable() further up in the driver. Fixes: 7df5081cbf5e ("serial: stm32: Add RS485 RTS GPIO control") Cc: stable@vger.kernel.org # v5.9+ Cc: Marek Vasut <marex@denx.de> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/6059eab35dba394468335ef640df8b0050fd9dbd.1662886616.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Make ->set_termios() old ktermios constIlpo Järvinen2022-08-301-1/+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>
* Merge tag 'tty-6.0-rc1' of ↵Linus Torvalds2022-08-081-1/+78
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial driver updates from Greg KH: "Here is the big set of tty and serial driver changes for 6.0-rc1. It was delayed from last week as I wanted to make sure the last commit here got some good testing in linux-next and elsewhere as it seemed to show up only late in testing for some reason. Nothing major here, just lots of cleanups from Jiri and Ilpo to make the tty core cleaner (Jiri) and the rs485 code simpler to use (Ilpo). Also included in here is the obligatory n_gsm updates from Daniel Starke and lots of tiny driver updates and minor fixes and tweaks for other smaller serial drivers. All of these have been in linux-next for a while with no reported problems" * tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (186 commits) tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements tty: amiserial: Fix comment typo tty: serial: document uart_get_console() tty: serial: serial_core, reformat kernel-doc for functions Documentation: serial: link uart_ops properly Documentation: serial: move GPIO kernel-doc to the functions Documentation: serial: dedup kernel-doc for uart functions Documentation: serial: move uart_ops documentation to the struct dt-bindings: serial: snps-dw-apb-uart: Document Rockchip RV1126 serial: mvebu-uart: uart2 error bits clearing tty: serial: fsl_lpuart: correct the count of break characters serial: stm32: make info structs static to avoid sparse warnings serial: fsl_lpuart: zero out parity bit in CS7 mode tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate. serial: 8250_bcm2835aux: Add missing clk_disable_unprepare() tty: vt: initialize unicode screen buffer serial: remove VR41XX serial driver serial: 8250: lpc18xx: Remove redundant sanity check for RS485 flags serial: 8250_dwlib: remove redundant sanity check for RS485 flags dt_bindings: rs485: Correct delay values ...
| * serial: stm32: make info structs static to avoid sparse warningsBen Dooks2022-07-281-0/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The info structs are local only to the stm32-usart.c driver and are triggering sparse warnings about being undecalred. Move these into the main driver code and make them static to avoid the following warnings: drivers/tty/serial/stm32-usart.h:42:25: warning: symbol 'stm32f4_info' was not declared. Should it be static? drivers/tty/serial/stm32-usart.h:63:25: warning: symbol 'stm32f7_info' was not declared. Should it be static? drivers/tty/serial/stm32-usart.h:85:25: warning: symbol 'stm32h7_info' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben-linux@fluff.org> Link: https://lore.kernel.org/r/20220721212430.453192-1-ben-linux@fluff.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: Embed rs485_supported to uart_portIlpo Järvinen2022-07-081-1/+1
| | | | | | | | | | | | | | | | | | | | Embed rs485_supported to uart_port to allow serial core to tweak it as needed. Reviewed-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220704094515.6831-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: take termios_rwsem for ->rs485_config() & pass termios as paramIlpo Järvinen2022-06-271-1/+1
| | | | | | | | | | | | | | | | | | To be able to alter ADDRB within ->rs485_config(), take termios_rwsem before calling ->rs485_config() and pass termios. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220624204210.11112-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: stm32: Fill in rs485_supportedIlpo Järvinen2022-06-101-0/+8
| | | | | | | | | | | | | | | | Add information on supported serial_rs485 features. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220606100433.13793-22-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: stm32: Clear prev values before setting RTS delaysIlpo Järvinen2022-06-301-0/+2
|/ | | | | | | | | | | | | The code lacks clearing of previous DEAT/DEDT values. Thus, changing values on the fly results in garbage delays tending towards the maximum value as more and more bits are ORed together. (Leaving RS485 mode would have cleared the old values though). Fixes: 1bcda09d2910 ("serial: stm32: add support for RS485 hardware control mode") Cc: stable <stable@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220627150753.34510-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32-usart: Correct CSIZE, bits, and parityIlpo Järvinen2022-05-191-3/+12
| | | | | | | | | | | | | | | | | Add CSIZE sanitization for unsupported CSIZE configurations. In addition, if parity is asked for but CSx was unsupported, the sensible result is CS8+parity which requires setting USART_CR1_M0 like with 9 bits. Incorrect CSIZE results in miscalculation of the frame bits in tty_get_char_size() or in its predecessor where the roughly the same code is directly within uart_update_timeout(). Fixes: c8a9d043947b (serial: stm32: fix word length configuration) Cc: Erwan Le Ray <erwan.leray@st.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220519081808.3776-9-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: Use TC interrupt to deassert GPIO RTS in RS485 modeMarek Vasut2022-05-051-2/+40
| | | | | | | | | | | | | | | | | | 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>
* serial: stm32: Factor out GPIO RTS toggling into separate functionMarek Vasut2022-05-051-21/+38
| | | | | | | | | | | | | | | | | 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>
* serial: stm32: add earlycon supportValentin Caron2022-04-221-0/+51
| | | | | | | | | 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>
* serial: stm32: add KGDB supportValentin Caron2022-04-221-2/+35
| | | | | | | | | | | 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>
* serial: stm32: remove infinite loop possibility in putchar functionValentin Caron2022-04-221-3/+9
| | | | | | | | | 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>
* serial: stm32: remove redundant code in rs485_configLino Sanfilippo2022-04-151-7/+2
| | | | | | | | | | | | | In uart_set_rs485_config() the serial core already ensures that only one of both options RTS on send or RTS after send is set. It also assigns the passed serial_rs485 struct to the uart port. So remove the check and the assignment from the drivers rs485_config() function to avoid redundancy. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Link: https://lore.kernel.org/r/20220410104642.32195-4-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: make uart_console_write->putchar()'s character an unsigned charJiri Slaby2022-03-031-1/+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>
* serial: stm32: enable / disable wake irqs for mcrtl_gpio wakeup sourcesErwan Le Ray2022-02-081-1/+2
| | | | | | | | | | Enable mctrl_gpio wake_irq if device_may_wakeup when usart is suspended, and disable mctrl_gpios wake_irq if device_may_wakeup when usart is resumed. Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Link: https://lore.kernel.org/r/20220203171644.12231-3-erwan.leray@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: fix software flow control transferValentin Caron2022-01-261-1/+1
| | | | | | | | | | | | | x_char is ignored by stm32_usart_start_tx() when xmit buffer is empty. Fix start_tx condition to allow x_char to be sent. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Cc: stable <stable@vger.kernel.org> Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220111164441.6178-3-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: prevent TDR register overwrite when sending x_charValentin Caron2022-01-261-0/+12
| | | | | | | | | | | | | | | | When sending x_char in stm32_usart_transmit_chars(), driver can overwrite the value of TDR register by the value of x_char. If this happens, the previous value that was present in TDR register will not be sent through uart. This code checks if the previous value in TDR register is sent before writing the x_char value into register. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Cc: stable <stable@vger.kernel.org> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220111164441.6178-2-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: correct loop for dma error handlingValentin Caron2022-01-061-3/+2
| | | | | | | | | | | | In this error handling, "transmit_chars_dma" function will call "transmit_chars_pio" once per characters. But "transmit_chars_pio" will continue to send characters while xmit buffer is not empty. Remove this useless loop, one call is sufficient. Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220104182445.4195-5-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: fix flow control transfer in DMA modeValentin Caron2022-01-061-0/+3
| | | | | | | | | | | | If flow control is enabled, framework will call stop_tx to pause transfer and then call start_tx to resume transfer. Clear USART_CR3_DMAT bit in stop_tx ops to pause DMA transfer. Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220104182445.4195-4-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: stm32: rework TX DMA state conditionValentin Caron2022-01-061-18/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | TX DMA state condition is handled by tx_dma_busy boolean. This boolean is set when dma descriptor is requested and reset when dma channel is stopped (dma_terminate). In stm32_usart_serial_remove(), stm32_usart_stop_tx() and stm32_usart_transmit_chars_dma() fallback error case, DMA channel is stopped but tx_dma_busy is not handled. Rework the driver by using two new functions to solve this issue: - stm32_usart_tx_dma_started return true if DMA TX have a descriptor. - stm32_usart_tx_dma_enabled return true if DMAT bit is set. stm32_usart_tx_dma_started uses tx_dma_busy flag to prevent dual DMA transaction at the same time. This flag is set when a DMA transaction begins and is unset when dmaengine_terminate_async function is called. A new DMA transaction cannot be created if this flag is set. Create a new function "stm32_usart_tx_dma_terminate" to be sure the flag is unset after each call of dmaengine_terminate_async. Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220104182445.4195-3-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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