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path: root/drivers/tty/serial/fsl_lpuart.c
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2021-05-13serial: fsl_lpuart: split sysrq handlingMichael Walle1-6/+6
Instead of uart_handle_sysrq_char() use uart_prepare_sysrq_char() and uart_unlock_and_check_sysrq(). This will call handle_sysrq() without holding the port lock, which in turn let us drop the spin_trylock hack. Suggested-by: Johan Hovold <johan@kernel.org> Signed-off-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20210512141255.18277-5-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13serial: fsl_lpuart: don't restore interrupt state in ISRMichael Walle1-14/+8
>From commit 75f4e830fa9c ("serial: do not restore interrupt state in sysrq helper"): Since commit 81e2073c175b ("genirq: Disable interrupts for force threaded handlers") interrupt handlers that are not explicitly requested as threaded are always called with interrupts disabled and there is no need to save the interrupt state when taking the port lock. Apply this also to fsl_lpuart in prepartion for sysrq handling with uart_unlock_and_check_sysrq(). Signed-off-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20210512141255.18277-4-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13serial: fsl_lpuart: use UARTDATA_MASK macroMichael Walle1-2/+2
Use the corresponding macro instead of the magic number. While at it, drop the useless cast to "unsigned char". Signed-off-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20210512141255.18277-3-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13serial: fsl_lpuart: don't modify arbitrary data on lpuart32Michael Walle1-1/+1
lpuart_rx_dma_startup() is used for both the 8 bit and the 32 bit version of the LPUART. Modify the UARTCR only for the 8 bit version. Fixes: f4eef224a09f ("serial: fsl_lpuart: add sysrq support when using dma") Signed-off-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20210512141255.18277-2-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13tty: serial: fsl_lpuart: fix the potential risk of division or modulo by zeroSherry Sun1-0/+3
We should be very careful about the register values that will be used for division or modulo operations, althrough the possibility that the UARTBAUD register value is zero is very low, but we had better to deal with the "bad data" of hardware in advance to avoid division or modulo by zero leading to undefined kernel behavior. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20210427021226.27468-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-20serial: fsl_lpuart: Use of_device_get_match_data()Fabio Estevam1-3/+1
The retrieval of driver data via of_device_get_match_data() can make the code simpler. Use of_device_get_match_data() to simplify the code. Signed-off-by: Fabio Estevam <festevam@gmail.com> Link: https://lore.kernel.org/r/20210118124447.1632092-1-festevam@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-28tty: serial: fsl_lpuart: LS1021A has a FIFO size of 16 words, like LS1028AVladimir Oltean1-6/+7
Prior to the commit that this one fixes, the FIFO size was derived from the read-only register LPUARTx_FIFO[TXFIFOSIZE] using the following formula: TX FIFO size = 2 ^ (LPUARTx_FIFO[TXFIFOSIZE] - 1) The documentation for LS1021A is a mess. Under chapter 26.1.3 LS1021A LPUART module special consideration, it mentions TXFIFO_SZ and RXFIFO_SZ being equal to 4, and in the register description for LPUARTx_FIFO, it shows the out-of-reset value of TXFIFOSIZE and RXFIFOSIZE fields as "011", even though these registers read as "101" in reality. And when LPUART on LS1021A was working, the "101" value did correspond to "16 datawords", by applying the formula above, even though the documentation is wrong again (!!!!) and says that "101" means 64 datawords (hint: it doesn't). So the "new" formula created by commit f77ebb241ce0 has all the premises of being wrong for LS1021A, because it relied only on false data and no actual experimentation. Interestingly, in commit c2f448cff22a ("tty: serial: fsl_lpuart: add LS1028A support"), Michael Walle applied a workaround to this by manually setting the FIFO widths for LS1028A. It looks like the same values are used by LS1021A as well, in fact. When the driver thinks that it has a deeper FIFO than it really has, getty (user space) output gets truncated. Many thanks to Michael for pointing out where to look. Fixes: f77ebb241ce0 ("tty: serial: fsl_lpuart: correct the FIFO depth size") Suggested-by: Michael Walle <michael@walle.cc> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20201023013429.3551026-1-vladimir.oltean@nxp.com Reviewed-by:Fugang Duan <fugang.duan@nxp.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05serial: fsl_lpuart: add sysrq support when using dmaAngelo Dureghello1-0/+57
Add handling of magic sysrq keys when using dma/edma. Tested by sending BREAK followed by a sysrq command inside a 5 secs time window, by: echo 1 > /proc/sys/kernel/sysrq BREAK + h, t, e, b, c Tested also sending a command after 5 secs after BREAK, that's properly ignored. Signed-off-by: Angelo Dureghello <angelo.dureghello@timesys.com> Link: https://lore.kernel.org/r/20201004161144.1307174-1-angelo.dureghello@timesys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-30tty: serial: fsl_lpuart: fix lpuart32_poll_get_charPeng Fan1-1/+1
The watermark is set to 1, so we need to input two chars to trigger RDRF using the original logic. With the new logic, we could always get the char when there is data in FIFO. Suggested-by: Fugang Duan <fugang.duan@nxp.com> Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/20200929095509.21680-1-peng.fan@nxp.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-30tty: serial: lpuart: fix lpuart32_write usagePeng Fan1-8/+6
The 2nd and 3rd parameter were wrongly used, and cause kernel abort when doing kgdb debug. Fixes: 1da17d7cf8e2 ("tty: serial: fsl_lpuart: Use appropriate lpuart32_* I/O funcs") Cc: stable <stable@vger.kernel.org> Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/20200929091920.22612-1-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-28serial: fsl_lpuart: Fix typo in "transfer"Fabio Estevam1-2/+2
Fix two occurrences where "transfer" is spelled incorrectly. Signed-off-by: Fabio Estevam <festevam@gmail.com> Link: https://lore.kernel.org/r/20200818224457.16507-1-festevam@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-27tty: serial: fsl_lpuart: minimum baud rate supportVabhav Sharma1-0/+3
The formula for the baud rate is baud rate = "baud clock / ((OSR+1) × SBR) Algorithm used in function lpuart32_serial_setbrg() only changes the SBR. Even with maxmum value put in, OSR stays at 0x7 and the lowest baud rate would be ~ 2600 bps Update the algorithm to allow driver operation at 1200,2400 or 600 bps Signed-off-by: Vabhav Sharma <vabhav.sharma@nxp.com> Link: https://lore.kernel.org/r/1593170434-13524-1-git-send-email-vabhav.sharma@oss.nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-15tty: serial: fsl_lpuart: Use __maybe_unused instead of #if CONFIG_PM_SLEEPAnson Huang1-4/+2
Use __maybe_unused for power management related functions to simplify the code. Signed-off-by: Anson Huang <Anson.Huang@nxp.com> Link: https://lore.kernel.org/r/1589547481-25932-1-git-send-email-Anson.Huang@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-15serial: Allow uart_get_rs485_mode() to return errnoLukas Wunner1-1/+4
We're about to amend uart_get_rs485_mode() to support a GPIO pin for rs485 bus termination. Retrieving the GPIO descriptor may fail, so allow uart_get_rs485_mode() to return an errno and change all callers to check for failure. The GPIO descriptor is going to be stored in struct uart_port. Pass that struct to uart_get_rs485_mode() in lieu of a struct device and struct serial_rs485, both of which are directly accessible from struct uart_port. A few drivers call uart_get_rs485_mode() before setting the struct device pointer in struct uart_port. Shuffle those calls around where necessary. [Heiko Stuebner did the ar933x_uart.c portion, hence his Signed-off-by.] Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/271e814af4b0db3bffbbb74abf2b46b75add4516.1589285873.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-23serial: fsl_lpuart: Change DMA failure messages to debug levelFabio Estevam1-6/+6
Currently the following messages are seen when booting i.MX8QXP: fsl-lpuart 5a060000.serial: DMA tx channel request failed, operating without tx DMA (-19) fsl-lpuart 5a060000.serial: DMA rx channel request failed, operating without rx DMA (-19) It is not really useful to have such messages on every boot, so change them to debug level instead. Signed-off-by: Fabio Estevam <festevam@gmail.com> Link: https://lore.kernel.org/r/20200416153453.18825-1-festevam@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16tty: serial: fsl_lpuart: make coverity happyMichael Walle1-3/+1
Coverity reports the following: var_compare_op: Comparing chan to null implies that chan might be null. 1234 if (chan) 1235 dmaengine_terminate_all(chan); 1236 Dereference after null check (FORWARD_NULL) var_deref_op: Dereferencing null pointer chan. 1237 dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); Technically, this is correct. But lpuart_dma_rx_free() is guarded by lpuart_dma_rx_use which is only true if there is a dma channel, see lpuart_rx_dma_startup(). In any way, this looks bogus. So remove the superfluous "if (chan)" check and make coverity happy. Fixes: a092ab25fdaa ("tty: serial: fsl_lpuart: fix DMA mapping") Signed-off-by: Michael Walle <michael@walle.cc> Reported-by: Colin Ian King <colin.king@canonical.com> Acked-by: Jiri Slaby <jslaby@suse.cz> Reviewed-by: Fabio Estevam <festevam@gmail.com> Link: https://lore.kernel.org/r/20200403174942.9594-1-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-26tty: serial: fsl_lpuart: fix return value checkingMichael Walle1-1/+1
The return value of lpuart_dma_tx_request() is an negative errno on failure and zero on success. Fixes: 159381df1442f ("tty: serial: fsl_lpuart: fix DMA operation when using IOMMU") Reported-by: Leonard Crestez <leonard.crestez@nxp.com> Signed-off-by: Michael Walle <michael@walle.cc> Reviewed-by: Fugang Duan <fugang.duan@nxp.com> Link: https://lore.kernel.org/r/20200325090658.25967-2-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-26tty: serial: fsl_lpuart: move dma_request_chan()Michael Walle1-13/+23
Move dma_request_chan() out of the atomic context. First this call should not be in the atomic context at all and second the dev_info_once() may cause a hang because because the console takes this spinlock, too. Fixes: 159381df1442f ("tty: serial: fsl_lpuart: fix DMA operation when using IOMMU") Reported-by: Leonard Crestez <leonard.crestez@nxp.com> Signed-off-by: Michael Walle <michael@walle.cc> Reviewed-by: Fugang Duan <fugang.duan@nxp.com> Tested-by: Leonard Crestez <leonard.crestez@nxp.com> Link: https://lore.kernel.org/r/20200325090658.25967-1-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-12tty: serial: fsl_lpuart: add LS1028A earlycon supportMichael Walle1-8/+43
Add a early_console_setup() for the LS1028A SoC with 32bit, little endian access. If the bootloader does a fixup of the clock-frequency node the baudrate divisor register will automatically be set. Signed-off-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20200306214433.23215-5-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-12tty: serial: fsl_lpuart: add LS1028A supportMichael Walle1-2/+25
The LS1028A uses little endian register access and has a different FIFO size encoding. Signed-off-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20200306214433.23215-4-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-12tty: serial: fsl_lpuart: fix DMA mappingMichael Walle1-20/+28
Use the correct device to request the DMA mapping. Otherwise the IOMMU doesn't get the mapping and it will generate a page fault. The error messages look like: [ 19.012140] arm-smmu 5000000.iommu: Unhandled context fault: fsr=0x402, iova=0xbbfff800, fsynr=0x3e0021, cbfrsynra=0x828, cb=9 [ 19.023593] arm-smmu 5000000.iommu: Unhandled context fault: fsr=0x402, iova=0xbbfff800, fsynr=0x3e0021, cbfrsynra=0x828, cb=9 This was tested on a custom board with a LS1028A SoC. Signed-off-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20200306214433.23215-3-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-12tty: serial: fsl_lpuart: fix DMA operation when using IOMMUMichael Walle1-31/+57
The DMA channel might not be available at probe time. This is esp. the case if the DMA controller has an IOMMU mapping. There is also another caveat. If there is no DMA controller at all, dma_request_chan() will also return -EPROBE_DEFER. Thus we cannot test for -EPROBE_DEFER in probe(). Otherwise the lpuart driver will fail to probe if, for example, the DMA driver is not enabled in the kernel configuration. To workaround this, we request the DMA channel in _startup(). Other serial drivers do it the same way. Signed-off-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20200306214433.23215-2-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-06tty: serial: fsl_lpuart: free IDs allocated by IDAMichael Walle1-15/+24
Since commit 3bc3206e1c0f ("serial: fsl_lpuart: Remove the alias node dependence") the port line number can also be allocated by IDA, but in case of an error the ID will no be removed again. More importantly, any ID will be freed in remove(), even if it wasn't allocated but instead fetched by of_alias_get_id(). If it was not allocated by IDA there will be a warning: WARN(1, "ida_free called for id=%d which is not allocated.\n", id); Move the ID allocation more to the end of the probe() so that we still can use plain return in the first error cases. Fixes: 3bc3206e1c0f ("serial: fsl_lpuart: Remove the alias node dependence") Signed-off-by: Michael Walle <michael@walle.cc> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200303174306.6015-3-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-06Revert "tty: serial: fsl_lpuart: drop EARLYCON_DECLARE"Michael Walle1-0/+2
This reverts commit a659652f6169240a5818cb244b280c5a362ef5a4. This broke the earlycon on LS1021A processors because the order of the earlycon_setup() functions were changed. Before the commit the normal lpuart32_early_console_setup() was called. After the commit the lpuart32_imx_early_console_setup() is called instead. Fixes: a659652f6169 ("tty: serial: fsl_lpuart: drop EARLYCON_DECLARE") Signed-off-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20200303174306.6015-2-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-06tty: serial: fsl_lpuart: drop earlycon entry for i.MX8QXPPeng Fan1-1/+0
i.MX8QXP lpuart is compatible with i.MX7ULP, so no need an extra entry for i.MX8QXP. Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/1576822230-23125-4-git-send-email-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-06tty: serial: fsl_lpuart: support UPIO_MEM32 for lpuart32Peng Fan1-1/+3
"earlycon" no need to specify the value string since it uses stdout-path parameters. However when earlycon and normal console are not using the same uart port, we need specify value string to earlycon, this is what we need to do when support dual linux using jailhouse hypervisor. The 2nd linux will use the uart of the 1st linux as earlycon. earlycon=lpuart32,mmio32,0x5a060010,115200 not work for i.MX8QXP. It is because lpuart32_early_console_setup not support little endian. Since the original code is to support UPIO_MEM32BE, so if not UPIO_MEM32, we still take it as UPIO_MEM32BE Acked-by: Fugang Duan <fugang.duan@nxp.com> Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/1576822230-23125-3-git-send-email-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-06tty: serial: fsl_lpuart: drop EARLYCON_DECLAREPeng Fan1-2/+0
EARLYCON_DECLARE is just a wrapper of OF_EARLYCON_DECLARE, since we already have OF_EARLYCON_DECLARE for lpuart and lpuart32, so no need EARLYCON_DECLARE. Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/1576822230-23125-2-git-send-email-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-18tty/serial: Migrate fsl_lpuart to use has_sysrqDmitry Safonov1-8/+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. Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://lore.kernel.org/r/20191213000657.931618-19-dima@arista.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-05tty: serial: fsl_lpuart: use the sg count from dma_map_sgPeng Fan1-2/+2
The dmaengine_prep_slave_sg needs to use sg count returned by dma_map_sg, not use sport->dma_tx_nents, because the return value of dma_map_sg is not always same with "nents". When enabling iommu for lpuart + edma, iommu framework may concatenate two sgs into one. Fixes: 6250cc30c4c4e ("tty: serial: fsl_lpuart: Use scatter/gather DMA for Tx") Cc: <stable@vger.kernel.org> Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/1572932977-17866-1-git-send-email-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-04tty: serial: lpuart: Add RS485 support for 32-bit uart flavourPhilippe Schenker1-2/+63
This commits adds RS485 support for LPUART hardware that uses 32-bit registers. These are typically found in i.MX8 processors. Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com> Reviewed-by: Fugang Duan <fugang.duan@nxp.com> Link: https://lore.kernel.org/r/20191017141428.10330-3-philippe.schenker@toradex.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-04tty: serial: lpuart: Use defines that correspond to correct registerPhilippe Schenker1-2/+2
Use define from the 32-bit register description UARTMODIR_* instead of UARTMODEM_*. The value is the same, so there is no functional change. Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com> Reviewed-by: Stefan Agner <stefan.agner@toradex.com> Reviewed-by: Fugang Duan <fugang.duan@nxp.com> Link: https://lore.kernel.org/r/20191017141428.10330-2-philippe.schenker@toradex.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-04tty: serial: lpuart: Remove unnecessary code from set_mctrlPhilippe Schenker1-11/+0
Currently flow control is not working due to lpuart32_set_mctrl that is clearing TXCTSE bit in all cases. This bit gets earlier setup by lpuart32_set_termios. As I read in Documentation set_mctrl is also not meant for hardware flow control rather than gpio setting and clearing a RTS signal. Therefore I guess it is safe to remove the whole code in lpuart32_set_mctrl. This was tested with console on a i.MX8QXP SoC. Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com> Reviewed-by: Fugang Duan <fugang.duan@nxp.com> Link: https://lore.kernel.org/r/20191017141428.10330-1-philippe.schenker@toradex.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-07tty: serial: fsl_lpuart: Fix lpuart_flush_buffer()Andrey Smirnov1-1/+1
Fix incorrect read-modify-write sequence in lpuart_flush_buffer() that was reading from UARTPFIFO and writing to UARTCFIFO instead of operating solely on the latter. Fixes: 9bc19af9dacb ("tty: serial: fsl_lpuart: Flush HW FIFOs in .flush_buffer") Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Reported-by: Vivien Didelot <vivien.didelot@gmail.com> Tested-by: Vivien Didelot <vivien.didelot@gmail.com> Tested-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Fabio Estevam <festevam@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Jiri Slaby <jslaby@suse.com> Link: https://lore.kernel.org/r/20191004215537.5308-1-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Ignore TX/RX interrupts if DMA is enabledAndrey Smirnov1-2/+2
In a mixed DMA/IRQ use-case (e.g.: DMA for TX, IRQ for RX), interrupt handler might try to handle Rx/Tx condition it shouldn't. Change the code to only handle TX/RX event if corresponding path isn't being handled by DMA. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190805185701.22863-7-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Don't enable TIE in .startup() or .resume()Andrey Smirnov1-1/+1
Enabling TIE in .startup() callback causes the driver to start (or at least try) to transmit data before .start_tx() is called. Which, while harmless (since TIE handler will immediately disable it), is a no-op and shouldn't really happen. Drop UARTCR2_TIE from list of bits set in lpuart_startup(). This change will also not enable TIE in .resume(), but it seems that, similart to .startup(), transmit interrupt shouldn't be enabled there either. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190805185701.22863-6-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Introduce lpuart*_setup_watermark_enable()Andrey Smirnov1-22/+28
Most users of lpuart*_setup_watermark() enable identical set of flags right after the call, so combine those two action into a subroutine and make use of it. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190805185701.22863-5-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Introduce lpuart32_configure()Andrey Smirnov1-27/+21
Code doing final steps of TX/RX configuration in lpuart32_startup() and lpuart_resume() is identical, so move it into a standalone subroutine. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190805185701.22863-4-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Introduce lpuart_rx_dma_startup()Andrey Smirnov1-23/+17
Code doing initial DMA RX configuration in lpuart_startup() and lpuart32_startup() is exactly the same, so move it into a standalone subroutine. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190805185701.22863-3-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Introduce lpuart_tx_dma_startup()Andrey Smirnov1-30/+23
Code configure DMA TX path in lpuart_startup(), lpuart32_startup() and lpuart_resume() is doing exactly the same thing, so move it into a standalone subroutine. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190805185701.22863-2-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: Remove dev_err() usage after platform_get_irq()Stephen Boyd1-3/+1
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>
2019-09-04tty: serial: fsl_lpuart: Introduce lpuart_dma_shutdown()Andrey Smirnov1-24/+18
Last steps of .shutdown() code are identical for lpuart and lpuart32 cases, so move it all into a standalone subroutine. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190729195226.8862-19-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Drop unnecessary lpuart*_stop_tx()Andrey Smirnov1-4/+0
By the time lpuart_shutdown() calls lpuart_stop_tx() UARTCR2_TE and UARTCR2_TIE (which the latter will clear) are already cleared, so that function call should effectively be a no-op. Moreso, lpuart_stop_tx() is expected to be executed with port spinlock held, which the caller doesn't. Given all that, drop the call to lpuart_stop_tx() in lpuart_shutdown(). In case of lpuart32_shutdown()/lpuart32_stop_tx(), TIE won't even be set if lpuart_dma_tx_use is true. Drop it there as well. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190729195226.8862-18-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Introduce lpuart_stopped_or_empty()Andrey Smirnov1-7/+10
The check for uart_circ_empty(xmit) || uart_tx_stopped(&sport->port) appears in multiple places in the driver. Move it into a helper function. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190729195226.8862-17-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Use cpu_relax() instead of barrier()Andrey Smirnov1-2/+2
Use cpu_relax() instead of barrier() in a tight polling loops to make them a bit more idiomatic. Should also improve things on ARM64 a bit since cpu_relax() will expand into "yield" instruction there. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190729195226.8862-16-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Introduce lpuart_wait_bit_set()Andrey Smirnov1-20/+22
Busy polling on a bit in a register is used in multiple places in the driver. Move it into a shared function. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190729195226.8862-15-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Use appropriate lpuart32_* I/O funcsAndrey Smirnov1-14/+14
When dealing with 32-bit variant of LPUART IP block appropriate I/O helpers have to be used to properly deal with endianness differences. Change all of the offending code to do that. Fixes: a5fa2660d787 ("tty/serial/fsl_lpuart: Add CONSOLE_POLL support for lpuart32.") Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190729195226.8862-14-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Clear CSTOPB unconditionallyAndrey Smirnov1-2/+1
Clearing CSTOPB bit if it is set is functionally equivalent to jsut clearing it unconditionally. Drop unnecessary check. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190729195226.8862-13-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Drop unnecessary extra parenthesisAndrey Smirnov1-10/+10
Drop unnecessary extra parenthesis in the driver. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190729195226.8862-12-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fsl_lpuart: Drop no-op bit opearationAndrey Smirnov1-4/+2
The check for termios->c_cflag & CRTSCTS ensure that if we reach else branch, CRTSCTS in termios->c_cflag is already going to be cleard. Doing so explicitly there is not necessary. Drop it. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190729195226.8862-11-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: serial: fls_lpuart: Split shared TX IRQ handler into twoAndrey Smirnov1-26/+35
While sharing code for Tx interrupt handler between 8 and 32 bit variant of the peripheral saves a bit of code duplication it also adds quite a number of lpuart_is_32() checks which makes it harder to understand. Move shared bits back into corresponding lpuart*_transmit_buffer functions, split lpuart_txint into lpuart_txint and lpuart32_txint so we can drop all extra lpuart_is_32() check and make the code flow more linear. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Cc: Chris Healy <cphealy@gmail.com> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-imx@nxp.com Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/20190729195226.8862-10-andrew.smirnov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>