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path: root/drivers/tty/serial/xilinx_uartps.c
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2020-03-24serial: uartps: Add TACTIVE check in cdns_uart_tx_empty functionRaviteja Narayanam
Make sure that all bytes are transmitted out of Uart by monitoring CDNS_UART_SR_TACTIVE bit as well. Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xilinx.com> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Acked-by: Maarten Brock <m.brock@vanmierlo.com> Link: https://lore.kernel.org/r/e2514818af5973be291cc117d07739f068b71639.1584610774.git.shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-24serial: uartps: Remove unconditional wait inside set_termiosRaviteja Narayanam
set_termios function should not wait for the transmit FIFO empty (CDNS_UART_SR_TXEMPTY) unconditionally. The tty layer takes care of it based on the parameter passed (TCSANOW/TCSADRAIN/TCSAFLUSH). Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xilinx.com> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/536e190dd5bbb474007a67e6323c048288942a28.1584610774.git.shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14serial: xilinx_uartps: set_mctrl sets RTS and DTRMaarten Brock
set_mctrl now sets RTS and DTR. Signed-off-by: Maarten Brock <m.brock@vanmierlo.com> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/1574687731-21563-3-git-send-email-shubhrajyoti.datta@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14serial: xilinx_uartps: set_termios sets flowcontrolMaarten Brock
Let set_termios enable/disable automatic flow control. set_mctrl should not touch automatic flow control. Signed-off-by: Maarten Brock <m.brock@vanmierlo.com> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/1574687731-21563-2-git-send-email-shubhrajyoti.datta@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14serial: xilinx_uartps: Let get_mctrl return statusMaarten Brock
Some of the applications like microcom do not work if modem is disabled. To fix them we always return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR instead of 0 when using cts_override. Make get_mctrl return actual status when not using cts_override. Signed-off-by: Maarten Brock <m.brock@vanmierlo.com> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/1574687731-21563-1-git-send-email-shubhrajyoti.datta@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-18tty/serial: Migrate xilinx_uartps to use has_sysrqDmitry Safonov
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: Michal Simek <michal.simek@xilinx.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://lore.kernel.org/r/20191213000657.931618-53-dima@arista.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-04serial: uartps: Fix uartps_major handlingMichal Simek
There are two parts which should be fixed. The first one is to assigned uartps_major at the end of probe() to avoid complicated logic when something fails. The second part is initialized uartps_major number to 0 when last device is removed. This will ensure that on next probe driver will ask for new dynamic major number. Fixes: ab262666018d ("serial: uartps: Use the same dynamic major number for all ports") Reported-by: Paul Thomas <pthomas8589@gmail.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Link: https://lore.kernel.org/r/d2652cda992833315c4f96f06953eb547f928918.1570194248.git.michal.simek@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04xilinx_uartps.c: suppress "may be used uninitialised" warningStephen Rothwell
A powerpc allyesconfig build produces this warning: In file included from include/linux/radix-tree.h:16, from include/linux/idr.h:15, from include/linux/kernfs.h:13, from include/linux/sysfs.h:16, from include/linux/kobject.h:20, from include/linux/device.h:16, from include/linux/platform_device.h:13, from drivers/tty/serial/xilinx_uartps.c:16: drivers/tty/serial/xilinx_uartps.c: In function 'cdns_uart_console_write': include/linux/spinlock.h:288:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized] _raw_spin_unlock_irqrestore(lock, flags); \ ^~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/tty/serial/xilinx_uartps.c:1197:16: note: 'flags' was declared here unsigned long flags; ^~~~~ It looks like gcc just can't track the relationship between "locked" and "flags", and it is obvious that "flags" won't be used when "locked" is zero, so the simplest thing is to initialise flags. Cc: Jiri Slaby <jslaby@suse.com> Cc: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Link: https://lore.kernel.org/r/20190731160557.6a09c3e1@canb.auug.org.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: uartps: Remove useless return from cdns_uart_poll_put_charNava kishore Manne
There is no reason to call return at the end of function which should return void. The patch is also remove one checkpatch warning: WARNING: void function return statements are not generally useful + return; +} Fixes: 6ee04c6c5488 ("tty: xuartps: Add polled mode support for xuartps") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: uartps: Do not add a trailing semicolon to macroNava kishore Manne
This patch fixes this checkpatch warning: WARNING: macros should not use a trailing semicolon +#define to_cdns_uart(_nb) container_of(_nb, struct cdns_uart, \ + clk_rate_change_nb); Fixes: d9bb3fb12685 ("tty: xuartps: Rebrand driver as Cadence UART") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: uartps: Fix long line over 80 charsNava kishore Manne
Trivial patch which fixes one checkpatch warning: WARNING: line over 80 characters + !(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)) { Fixes: c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: uartps: Fix multiple line dereferenceNava kishore Manne
Trivial patch which fixes this checkpatch warning: WARNING: Avoid multiple line dereference - prefer 'port->state->xmit.tail' + port->state->xmit.buf[port->state->xmit. + tail], port->membase + CDNS_UART_FIFO); Fixes: c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: uartps: Use octal permission for module_param()Nava kishore Manne
Octal permission is preffered compare to symbolic one. This patch fixes checkpatch warnings: Symbolic permissions 'S_IRUGO' are not preferred. Consider using octal permissions '0444'. Fixes: 85baf542d54e ("tty: xuartps: support 64 byte FIFO size") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18serial: uartps: Use the same dynamic major number for all portsShubhrajyoti Datta
Let kernel to find out major number dynamically for the first device and then reuse it for other instances. This fixes the issue that each uart is registered with a different major number. After the patch: crw------- 1 root root 253, 0 Jun 10 08:31 /dev/ttyPS0 crw--w---- 1 root root 253, 1 Jan 1 1970 /dev/ttyPS1 Fixes: 024ca329bfb9 ("serial: uartps: Register own uart console and driver structures") Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-10serial: uartps: Add a timeout to the tx empty waitShubhrajyoti Datta
In case the cable is not connected then the target gets into an infinite wait for tx empty. Add a timeout to the tx empty wait. Reported-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-10serial: uartps: Move the spinlock after the read of the tx emptyShubhrajyoti Datta
Currently we are doing a read of the status register. Move the spinlock after that as the reads need not be spinlock protected. This patch prevents relaxing the cpu with spinlock held. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-29serial: uartps: Add support for cts-overrideShubhrajyoti Datta
Having flow is configurable. Add support for the same by checking for cts-override. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-01tty: xilinx_uartps: Correct return value in probeRajan Vaja
Existing driver checks for alternate clock if devm_clk_get() fails and returns error code for last clock failure. If xilinx_uartps is called before clock driver, devm_clk_get() returns -EPROBE_DEFER. In this case, probe should not check for alternate clock as main clock is already present in DTS and return -EPROBE_DEFER only. This patch fixes it by not checking for alternate clock when main clock get returns -EPROBE_DEFER. Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-19serial: uartps: Fix stuck ISR if RX disabled with non-empty FIFOAnssi Hannula
If RX is disabled while there are still unprocessed bytes in RX FIFO, cdns_uart_handle_rx() called from interrupt handler will get stuck in the receive loop as read bytes will not get removed from the RX FIFO and CDNS_UART_SR_RXEMPTY bit will never get set. Avoid the stuck handler by checking first if RX is disabled. port->lock protects against race with RX-disabling functions. This HW behavior was mentioned by Nathan Rossi in 43e98facc4a3 ("tty: xuartps: Fix RX hang, and TX corruption in termios call") which fixed a similar issue in cdns_uart_set_termios(). The behavior can also be easily verified by e.g. setting CDNS_UART_CR_RX_DIS at the beginning of cdns_uart_handle_rx() - the following loop will then get stuck. Resetting the FIFO using RXRST would not set RXEMPTY either so simply issuing a reset after RX-disable would not work. I observe this frequently on a ZynqMP board during heavy RX load at 1M baudrate when the reader process exits and thus RX gets disabled. Fixes: 61ec9016988f ("tty/serial: add support for Xilinx PS UART") Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19serial: uartps: Fix interrupt mask issue to handle the RX interrupts properlyNava kishore Manne
This patch Correct the RX interrupt mask value to handle the RX interrupts properly. Fixes: c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19serial: uartps: Fix error path when alloc failedMichal Simek
When cdns_uart_console allocation failed there is a need to also clear ID from ID list. Fixes: ae1cca3fa347 ("serial: uartps: Change uart ID port allocation") Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19serial: uartps: Check if the device is a consoleShubhrajyoti Datta
While checking for console_suspend_enabled also check if the device is a console. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19serial: uartps: Add the device_init_wakeupShubhrajyoti Datta
Initialise the device wakeup. The device_init_wakeup is needed for the wakeup to work by default. Uart can be configured as the primary wakeup source so it is good to enable wakeup by default. The same functionality is enabled also by 8250_omap, atmel_serial, omap-serial and stm32-usart. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-06Revert "tty: xilinx_uartps: Correct return value in probe"Greg Kroah-Hartman
This reverts commit eca42d4cf3c591c36312c52707e0a712e0c7256a. During review it was rejected, so drop it from the tree. Cc: Rajan Vaja <RAJANV@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty: xilinx_uartps: Correct return value in probeRajan Vaja
Existing driver checks for alternate clock if devm_clk_get() fails and returns error code for last clock failure. If xilinx_uartps is called before clock driver, devm_clk_get() returns -EPROBE_DEFER. In this case, probe should not check for alternate clock as main clock is already present in DTS and return -EPROBE_DEFER only. This patch fixes it by not checking for alternate clock when main clock get returns -EPROBE_DEFER. Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-09serial: set suppress_bind_attrs flag only if builtinAnders Roxell
When the test 'CONFIG_DEBUG_TEST_DRIVER_REMOVE=y' is enabled, arch_initcall(pl011_init) came before subsys_initcall(default_bdi_init). devtmpfs gets killed because we try to remove a file and decrement the wb reference count before the noop_backing_device_info gets initialized. [ 0.332075] Serial: AMBA PL011 UART driver [ 0.485276] 9000000.pl011: ttyAMA0 at MMIO 0x9000000 (irq = 39, base_baud = 0) is a PL011 rev1 [ 0.502382] console [ttyAMA0] enabled [ 0.515710] Unable to handle kernel paging request at virtual address 0000800074c12000 [ 0.516053] Mem abort info: [ 0.516222] ESR = 0x96000004 [ 0.516417] Exception class = DABT (current EL), IL = 32 bits [ 0.516641] SET = 0, FnV = 0 [ 0.516826] EA = 0, S1PTW = 0 [ 0.516984] Data abort info: [ 0.517149] ISV = 0, ISS = 0x00000004 [ 0.517339] CM = 0, WnR = 0 [ 0.517553] [0000800074c12000] user address but active_mm is swapper [ 0.517928] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 0.518305] Modules linked in: [ 0.518839] CPU: 0 PID: 13 Comm: kdevtmpfs Not tainted 4.19.0-rc5-next-20180928-00002-g2ba39ab0cd01-dirty #82 [ 0.519307] Hardware name: linux,dummy-virt (DT) [ 0.519681] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 0.519959] pc : __destroy_inode+0x94/0x2a8 [ 0.520212] lr : __destroy_inode+0x78/0x2a8 [ 0.520401] sp : ffff0000098c3b20 [ 0.520590] x29: ffff0000098c3b20 x28: 00000000087a3714 [ 0.520904] x27: 0000000000002000 x26: 0000000000002000 [ 0.521179] x25: ffff000009583000 x24: 0000000000000000 [ 0.521467] x23: ffff80007bb52000 x22: ffff80007bbaa7c0 [ 0.521737] x21: ffff0000093f9338 x20: 0000000000000000 [ 0.522033] x19: ffff80007bbb05d8 x18: 0000000000000400 [ 0.522376] x17: 0000000000000000 x16: 0000000000000000 [ 0.522727] x15: 0000000000000400 x14: 0000000000000400 [ 0.523068] x13: 0000000000000001 x12: 0000000000000001 [ 0.523421] x11: 0000000000000000 x10: 0000000000000970 [ 0.523749] x9 : ffff0000098c3a60 x8 : ffff80007bbab190 [ 0.524017] x7 : ffff80007bbaa880 x6 : 0000000000000c88 [ 0.524305] x5 : ffff0000093d96c8 x4 : 61c8864680b583eb [ 0.524567] x3 : ffff0000093d6180 x2 : ffffffffffffffff [ 0.524872] x1 : 0000800074c12000 x0 : 0000800074c12000 [ 0.525207] Process kdevtmpfs (pid: 13, stack limit = 0x(____ptrval____)) [ 0.525529] Call trace: [ 0.525806] __destroy_inode+0x94/0x2a8 [ 0.526108] destroy_inode+0x34/0x88 [ 0.526370] evict+0x144/0x1c8 [ 0.526636] iput+0x184/0x230 [ 0.526871] dentry_unlink_inode+0x118/0x130 [ 0.527152] d_delete+0xd8/0xe0 [ 0.527420] vfs_unlink+0x240/0x270 [ 0.527665] handle_remove+0x1d8/0x330 [ 0.527875] devtmpfsd+0x138/0x1c8 [ 0.528085] kthread+0x14c/0x158 [ 0.528291] ret_from_fork+0x10/0x18 [ 0.528720] Code: 92800002 aa1403e0 d538d081 8b010000 (c85f7c04) [ 0.529367] ---[ end trace 5a3dee47727f877c ]--- Rework to set suppress_bind_attrs flag to avoid removing the device when CONFIG_DEBUG_TEST_DRIVER_REMOVE=y. This applies for pic32_uart and xilinx_uartps as well. Co-developed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-15of: base: Change logic in of_alias_get_alias_list()Michal Simek
Check compatible string first before setting up bit in bitmap to also cover cases that allocated bitfield is not big enough. Show warning about it but let driver to continue to work with allocated bitfield to keep at least some devices (included console which is commonly close to serial0) to work. Fixes: b1078c355d76 ("of: base: Introduce of_alias_get_alias_list() to check alias IDs") Fixes: ae1cca3fa347 ("serial: uartps: Change uart ID port allocation") Signed-off-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-11serial: uartps: Do not allow use aliases >= MAX_UART_INSTANCESMichal Simek
Aliases >= MAX_UART_INSTANCES is no problem to find out and use but in error path is necessary skip clearing bits in bitmap to ensure that only bits in allocated bitmap are handled and nothing beyond that. Without this patch when for example serial90 alias is used then in error patch bit 90 is clear in 32bit wide bitmap. Fixes: ae1cca3fa347 ("serial: uartps: Change uart ID port allocation") Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-02serial: uartps: Fix missing unlock on error in cdns_get_id()Wei Yongjun
Add the missing unlock before return from function cdns_get_id() in the error handling case. Fixes: ae1cca3fa347 ("serial: uartps: Change uart ID port allocation") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Reviewed-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-20serial: uartps: Change uart ID port allocationMichal Simek
For IPs which have alias algorightm all the time using that alias and minor number. It means serial20 alias ends up as ttyPS20. If alias is not setup for probed IP instance the first unused position is used but that needs to be checked if it is really empty because another instance doesn't need to be probed at that time. of_alias_get_alias_list() fills alias bitmap which exactly shows which ID is free. If alias pointing to different not compatible IP, it is free to use. cdns_get_id() call is placed below structure allocation to simplify error path. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18serial: uartps: Enable automatic flow controlMichal Simek
Enable automatic flow control which should ensure that there is no mainteinance in connection for zcu100 BT case. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Acked-by: Nava kishore Manne <navam@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18serial: uartps: Move Port ID to device data structureMichal Simek
Record port ID in device data structure to be have it connected to certain instance. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18serial: uartps: Register own uart console and driver structuresMichal Simek
Every instance is registering own struct console and struct uart_driver with minor number which corresponds to alias ID (or 0 now) and with 1 uart port. The same alias ID is saved to tty_driver->name_base which is key field for creating ttyPSX name. Because name_base and minor number are setup already there is no need to setup any port->line number because 0 is the right value. Unfortunately this driver is setting up major number to 0 for using dynamic assignment and kernel is allocating different major numbers for every instance instead of using the same major and different minor number. ~# ls -la /dev/ttyPS* crw------- 1 root root 252, 0 Jan 1 03:36 /dev/ttyPS0 crw--w---- 1 root root 253, 1 Jan 1 00:00 /dev/ttyPS1 When major number is not 0. For example 252 then major/minor combinations are in expected form ~# ls -la /dev/ttyPS* crw------- 1 root root 252, 0 Jan 1 04:04 /dev/ttyPS0 crw--w---- 1 root root 252, 1 Jan 1 00:00 /dev/ttyPS1 Driver is not freeing struct cdns_uart_console in case that instance is not used as console. The reason is that console is incorrectly unregistred and "console [0] disabled" message will be shown. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18serial: uartps: Change logic how console_port is setupMichal Simek
Change logic how console_port is setup by using CON_ENABLED flag instead of index. There will be unique cdns_uart_console() structures that's why code can't use id for console_port assignment. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18serial: uartps: Fill struct uart_driver in probe()Michal Simek
This is preparation step for dynamic port allocation without CDNS_UART_NR_PORTS macro. Fill the structure only once at probe. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18serial: uartps: Move register to probe based on run time detectionMichal Simek
Register uart driver in probe to be able to register one device with unique major/minor separately. Also calculate number of instances of this driver to be able to call uart_unregister_driver() when there is no instance. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18serial: uartps: Move alias reading higher in probe()Michal Simek
This cosmetic change is done only for having next patch much easier to read. Moving id setup higher in probe is not affecting any usage of this driver and it also simplify error path. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18serial: uartps: Do not use static struct uart_driver out of probe()Michal Simek
cdns_uart_suspend()/resume() and remove() are using static reference to struct uart_driver. Assign this reference to private data structure as preparation step for dynamic struct uart_driver allocation. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18serial: uartps: Fix suspend functionalityNava kishore Manne
The driver's suspend/resume functions were buggy. If UART node contains any child node in the DT and the child is established a communication path with the parent UART. The relevant /dev/ttyPS* node will be not available for other operations. If the driver is trying to do any operations like suspend/resume without checking the tty->dev status it leads to the kernel crash/hang. This patch fix this issue by call the device_may_wake() with the generic parameter of type struct device. in the uart suspend and resume paths. It also fixes a race condition in the uart suspend path(i.e uart_suspend_port() should be called at the end of cdns_uart_suspend API this path updates the same) Signed-off-by: Nava kishore Manne <navam@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18serial: uartps: Do not initialize field to zero againMichal Simek
Writing zero and NULLs to already initialized fields is not needed. Remove this additional writes. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18serial: uartps: console_setup() can't be placed to init sectionMichal Simek
When console device is rebinded, console_setup() is called again. But marking it as __init means that function will be clear after boot is complete. If console device is binded again console_setup() is not found and error "Unable to handle kernel paging request at virtual address" is reported. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-28serial: xuartps: remove unnecessary register writeHelmut Grohne
This writel writes the exact same value as the previous writel and is thus unnecessary. It accidentally became unnecessary in e3538c37ee38 ("tty: xuartps: Beautify read-modify writes"), but the new behaviour is now expected. Link: https://www.spinics.net/lists/linux-serial/msg23168.html Signed-off-by: Helmut Grohne <h.grohne@intenta.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-28serial: xuartps: reduce hardware TX race conditionHelmut Grohne
After sending data to the uart, the driver was waiting until the TX FIFO was empty (for every single char written). After that, TX was disabled by writing the original TX state to the status register. At that time however, the state machine could still be shifting characters. Not waiting can result in strange hardware states, especially when coupled with calls to cdns_uart_set_termios, whose symptom generally is garbage characters being received from uart or a hang. According to UG585, the TACTIVE bit of the channel status register indicates the shifter operation and we should be waiting for that bit to clear. Sending characters does not require the TX FIFO to be empty, but merely to not be full. So cdns_uart_console_putchar is updated accordingly. During tests with an instrumented kernel and an oscilloscope, we could determine that the chance of a race is reduced by this patch. It is not removed entirely. On the oscilloscope, one can see that disabling the transmitter early can result in the transmission hanging in the middle of a character for a tiny duration. This hiccup is enough to desynchronize with a remote device for a sequence of characters until a data bit doesn't match the start or stop bits anymore. Link: https://www.spinics.net/lists/linux-serial/msg23156.html Link: https://www.spinics.net/lists/linux-serial/msg26139.html Signed-off-by: Helmut Grohne <h.grohne@intenta.de> Acked-by: Sören Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-28serial: xuartps: fix typo in cdns_uart_startupHelmut Grohne
The bit mask changes in commit 6e14f7c1f2c2 ("tty: xuartps: Improve startup function") doesn't do what the commit message advertises. The original behaviour was clearing the RX_DIS bit, but due to missing ~, that bit is now the only bit kept. Currently, the regression is harmless, because the previous write to the control register sets it to TXRST | RXRST. Thus the RX_DIS bit is previously cleared. The *RST bits are cleared by the hardware, so this commit does not currently change behaviour, but makes future changes less risky. Link: https://www.spinics.net/lists/linux-serial/msg23157.html Signed-off-by: Helmut Grohne <h.grohne@intenta.de> Fixes: 6e14f7c1f2c2 ("tty: xuartps: Improve startup function") Reviewed-by: Sören Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-30Merge 4.17-rc3 into tty-nextGreg Kroah-Hartman
We want the tty and serial driver fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-25serial: uartps: Remove static port arrayMichal Simek
Allocate uart port structure dynamically. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-25serial: uartps: Move cnds_uart_get_port to probeMichal Simek
c&p this function to probe as preparation for removing cdns_uart_port[] static array. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-25serial: uartps: Use dynamic array for console portMichal Simek
Driver console functions are using pointer to static array with fixed size. There can be only one serial console at the time which is found by register_console(). register_console() is filling cons->index to port->line value. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-25serial: uartps: Remove console_initcall from the driverMichal Simek
register_console() is called from uart_add_one_port()->uart_configure_port() that's why register_console() is called twice. This patch remove console_initcall to call register_console() only from one location. Also based on my tests cdns_uart_console_setup() is not called from the first register_console() call. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23tty: serial: xuartps: Setup early console when uartclk is also passedMichal Simek
Baudrate calculation depends on requested baudrate and uart clock. This patch is checking that uartclk is also passed. The same logic is used 8250_early.c/init_port function. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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