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>
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>
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>
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>
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: ab26266601 ("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>
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>
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: 6ee04c6c54 ("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>
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: d9bb3fb126 ("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>
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: 024ca329bf ("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>
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>
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>
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>
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>
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: 61ec901698 ("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>
This patch Correct the RX interrupt mask value to handle the
RX interrupts properly.
Fixes: c8dbdc842d ("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>
When cdns_uart_console allocation failed there is a need to also clear
ID from ID list.
Fixes: ae1cca3fa3 ("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>
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>
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>
This reverts commit eca42d4cf3.
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>
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>
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: b1078c355d ("of: base: Introduce of_alias_get_alias_list() to check alias IDs")
Fixes: ae1cca3fa3 ("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>
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: ae1cca3fa3 ("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>
Add the missing unlock before return from function cdns_get_id()
in the error handling case.
Fixes: ae1cca3fa3 ("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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
This writel writes the exact same value as the previous writel and is
thus unnecessary. It accidentally became unnecessary in e3538c37ee
("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>
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>
The bit mask changes in commit 6e14f7c1f2 ("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: 6e14f7c1f2 ("tty: xuartps: Improve startup function")
Reviewed-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
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>
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>
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>
