Commit Graph

71 Commits

Author SHA1 Message Date
Julia Lawall
f098a0ae62 tty: xuartps: constify uart_ops structures
Check for uart_ops structures that are only stored in the ops field of a
uart_port structure.  This field is declared const, so uart_ops structures
that have this property can be declared as const also.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r disable optional_qualifier@
identifier i;
position p;
@@
static struct uart_ops i@p = { ... };

@ok@
identifier r.i;
struct uart_port e;
position p;
@@
e.ops = &i@p;

@bad@
position p != {r.p,ok.p};
identifier r.i;
struct uart_ops e;
@@
e@i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
 struct uart_ops i = { ... };
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-02 15:01:16 +02:00
Shubhrajyoti Datta
210417ce83 tty: xuartps: disable clocks when not used
Currently the clocks are enabled at probe and disabled
at remove. Instead enable the clocks when used.

Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25 13:50:53 -07:00
Michal Simek
93d7bbaa65 serial: xuartps: Enable OF earlycon support
Support early console setup via DT for all listed compatible strings.
Remove EARLYCON_DECLARE which was done by:
"Use common framework for earlycon declarations"
(sha1: 2eaa790989)
when OF_EARLYCON_DECLARE is defined.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-07 16:11:14 -08:00
Soren Brinkmann
07986580d0 tty: xuartps: Consolidate TX handling
start_tx and the ISR used largely identical code to transmit data.
Consolidate that in one place.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:23 -08:00
Soren Brinkmann
a8df6a5160 tty: xuartps: Remove '_OFFSET' suffix from #defines
Remove the _OFFSET suffix from all register defines which makes code a
little easier to read and avoids a few line breaks.

Suggested-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:23 -08:00
Soren Brinkmann
74ea66d4ca tty: xuartps: Improve sysrq handling
Handling magic sysrq included dropping a lock to avoid a deadlock that
happened when cdns_uart_console_write tried to acquire a lock in the
from the sysrq code path. By making the acquisition of the lock in
cdns_uart_console_write depending on port->sysrq, cdns_uart_handle_rx can be
simplified to simply call uart_handle_sysrq.

Suggested-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:23 -08:00
Soren Brinkmann
354fb1a7d7 tty: xuartps: Cleanup: Reformat if-else
Convert an if-else into the more common early return on error, reducing
the indent level of the happy path.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:23 -08:00
Soren Brinkmann
373e882f9e tty: xuartps: Refactor IRQ handling
The system could deadlock handling RX IRQs when RX-related IRQ
conditions became true while the receiver was disabled. To avoid this,
enable/disable the RX/TX IRQs together with the receiver/transmitter.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:23 -08:00
Soren Brinkmann
55861d11c5 tty: xuartps: Move request_irq to after setting up the HW
Request_irq() should be _after_ h/w programming, otherwise an
interrupt could be triggered and in-progress before the h/w has been
setup.

Reported-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:23 -08:00
Soren Brinkmann
5ede4a5cde tty: xuartps: Move RX path into helper function
Move RX-related IRQ handling into a helper function.
Fixes a problem where every char received after a parity or frame error
in the current isr will also be tagged as a parity or frame error.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
a19eda0f49 tty: xuartps: Acquire port lock for shutdown
Shutting down the UART port can happen while console operations are in
progress. Holding the port lock serializes these operations and avoids
the UART HW to be disabled in the middle of console prints.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
4c0b92ed9e tty: xuartps: Keep lock for whole ISR
The RX path in the interrupt handler released a lock unnecessarily.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
6e14f7c1f2 tty: xuartps: Improve startup function
The startup function is supposed to initialize the UART for receiving.
Hence, don't enable the TX part. Also, protect HW accesses with the port
lock.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
aea8f3ddcf tty: xuartps: Clear interrupt status register in shutdown
When shutting down the UART, clear the interrupt status register. Bits
in the ISR are cleared by writing them as '1'.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
ea8dd8e585 tty: xuartps: Don't consider circular buffer when enabling transmitter
Restarting the transmitter even if the circ buffer is empty may be
necessary to push out remaining data when the port is restarted after
being stopped.

Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
f0f54a806b tty: xuartps: Use spinlock to serialize HW access
Instead of disabling the IRQ, use the spin lock to serialize accesses to
the HW. This protects the driver from interference of non-IRQ callbacks
with each other and makes the driver more consistent in its
serialization method.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
e3538c37ee tty: xuartps: Beautify read-modify writes
Non-functional, formatting changes to ease reading the code.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Masahiro Yamada
54585ba036 serial: xuartps: add __init to earlycon write method
Early console functions are only used during the early boot stage.
This change just saves a small amount of memory footprint.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10 19:10:08 +02:00
Michal Simek
5c90c07b98 serial: xilinx: Use platform_get_irq to get irq description structure
For systems with CONFIG_SERIAL_OF_PLATFORM=y and device_type =
"serial"; property in DT of_serial.c driver maps and unmaps IRQ (because
driver probe fails). Then a driver is called but irq mapping is not
created that's why driver is failing again in again on request_irq().
Based on this use platform_get_irq() instead of platform_get_resource()
which is doing irq_desc allocation and driver itself can request IRQ.

Fix both xilinx serial drivers in the tree.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-28 14:26:21 +02:00
Thomas Betker
136debf707 serial: xuartps: Fix check in console_setup().
cdns_uart_console_setup() checks port->mapbase != 0, but the port may
not be initialized yet even if this condition is met [e.g., ioremap()
may have failed]. Check port->membase != NULL instead, similar to
cdns_early_console_setup().

Signed-off-by: Thomas Betker <thomas.betker@rohde-schwarz.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26 22:55:18 +01:00
Thomas Betker
19f22efdb6 serial: xuartps: Get rid of register access macros.
Get rid of cdns_uart_readl() and cdns_uart_writel() and just call
readl() and writel() directly.

Most of the patch was created by search-and-replace (I had to convert a
few lines manually, and break some lines longer than 80 columns):
* s/cdns_uart_readl(/readl(port->membase + /g
* s/cdns_uart_writel(\([^,]*\),/writel(\1, port->membase +/g

Signed-off-by: Thomas Betker <thomas.betker@rohde-schwarz.com>
Acked-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26 22:54:07 +01:00
Thomas Betker
0c39a467e7 serial: xuartps: Fix iobase use.
cdns_uart_get_port() sets port->iobase = 1 to "mark port in use", but
this "in use" condition is not checked anywhere else in the code. So
remove the line, keeping port->iobase = 0 (which also makes more sense).

Signed-off-by: Thomas Betker <thomas.betker@rohde-schwarz.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26 22:52:30 +01:00
Thomas Betker
6db6df0e4a serial: xuartps: Fix cdns_uart_port[] definition.
The code assumes that the array cdns_uart_port[] has dimension
CDNS_UART_NR_PORTS, so let us define it this way.

Signed-off-by: Thomas Betker <thomas.betker@rohde-schwarz.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26 22:52:29 +01:00
Thomas Betker
9646e4fee4 serial: xuartps: Fix register space size.
The register space size is 0x1000, and this value [not 0xfff] should be
provided to request_mem_region(), ioremap(), etc.

Signed-off-by: Thomas Betker <thomas.betker@rohde-schwarz.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26 22:52:29 +01:00
Fabian Frederick
ed0bb2323c tty: constify of_device_id array
of_device_id is always used as const.
(See driver.of_match_table and open firmware functions)

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Timur Tabi <timur@tabi.org>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26 22:49:10 +01:00
Peter Crosthwaite
f6415491c5 tty: serial: xilinx_uartps: Use Macro for ttyPS0
All instances of "ttyPS" use this macro except for this one. Convert
it.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07 03:28:57 +01:00
Nathan Rossi
6ecde472b0 tty: xuartps: Fix RX hang, and TX corruption in termios call
The implementation of flushing the RX FIFO breaks in a number of cases,
it is impossible to ensure an complete flush of the RX FIFO due to the
hardware not allowing the use of the FIFOs when the receiver is disabled
(Reading from the FIFO register does not remove it from the FIFO when
the RX_EN=0 or RX_DIS=1). Additionally during an initial set_termios
call where RX_DIS=1 causes a hang waiting forever for the RX FIFO to
empty. On top of this the FIFO will be cleared by the use of the RXRST
bits on the Control Register, making the RX flush pointless (as it does
not preserve the data read anyway).

Due to the TXRST the TX FIFO and transmitter can be interrupted during
frame trasmission, causing corruption and additionally data lost in the
FIFO. Most other serial drivers do not flush or clear the FIFOs during
a termios configuration change and as such do not have issues with
corruption. For this UART controller is it required that the TXRST/RXRST
bit be flagged during the change, this means that the data in the FIFO
will be dropped when changing configuration. In order to prevent data
loss and corruption of the transmitted data, wait until the TX FIFO is
empty before changing the configuration. The performance of this may
cause the set_termios call to take a longer amount of time especially
on lower baud rates, however it is comparable to the same performance
hit that a console_write call costs.

Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>
Acked-by: Anirudha Sarangi <anirudh@xilinx.com>
Acked-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Lars-Peter Clausen
19038ad9f0 tty: xuartps: Add support for setting modem control signals
Add support for setting the state of the DTR and RTS signals.

Acked-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 14:57:27 -08:00
Michal Simek
6fa62fc46e serial: cadence: Add generic earlycon support
Add earlycon support for the cadence serial port.
This is based on recent patches:
"tty/serial: pl011: add generic earlycon support"
(sha1: 0d3c673e78)
"tty/serial: add arm/arm64 semihosting earlycon"
(sha1: d50d7269eb)

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:32:37 -04:00
Greg Kroah-Hartman
882ebfc28c Merge 3.17-rc5 into tty-next
We want those fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-14 22:17:40 -07:00
Lars-Peter Clausen
6731af573a tty: xuartps: Fix tx_emtpy() callback
The tx_empty() callback currently checks the TXEMPTY bit in the interrupt
status register to decided whether the FIFO should be reported as empty or
not. The bit in this register gets set when the FIFO state transitions from
non-empty to empty but is cleared again in the interrupt handler. This means
it is not suitable to be used to decided whether the FIFO is currently empty
or not. Instead use the TXEMPTY bit from the status register which will be
set as long as the FIFO is empty.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-08 16:33:56 -07:00
Michal Simek
4ebe786554 tty: serial: xuartps: Remove .owner field for driver
There is no need to init .owner field.

Based on the patch from Peter Griffin <peter.griffin@linaro.org>
"mmc: remove .owner field for drivers using module_platform_driver"

This patch removes the superflous .owner field for drivers which
use the module_platform_driver API, as this is overriden in
platform_driver_register anyway."

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-08 16:09:13 -07:00
Alexander Shiyan
8b152f1096 serial: treewide: Remove empty implementations of enable_ms()
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-09 17:29:38 -07:00
Soren Brinkmann
d9bb3fb126 tty: xuartps: Rebrand driver as Cadence UART
Zynq's UART is Cadence IP. Make this visible in the prompt in kconfig
and additional comments in the driver.
This also renames functions and symbols, as far as possible without
breaking user space API, to reflect the Cadence origin. This is achieved
through simple search and replace:
 - s/XUARTPS/CDNS_UART/g
 - s/xuartps/cdns_uart/g
The only exceptions are PORT_XUARTPS and the driver name, which stay as is,
due to their exposure to user space. As well as the - no legacy -
compatibility string 'xlnx,xuartps'

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-24 16:21:51 -07:00
Soren Brinkmann
b494a5fae4 tty: xuartps: Don't write IRQ disable register to enable interrupts
A comment states, that, according to the data sheet, to enable
interrupts the disable register should be written, but the enable
register could be left untouched. And it suspsects a HW bug requiring
to write both.
Reviewing the data sheet, these statements seem wrong. Just as one would
expect. Writing to the enable/disable register enables/disables
interrupts.
Hence the misleading comment and needless write to the disable register
are removed from the enable sequence.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-24 16:21:51 -07:00
Soren Brinkmann
35dc5a538f tty: xuartps: Refactor read-modify-writes
A lot of read-modify-write sequences used a one-line statement which
nests a readl() within a writel(). Convert this into code sequences that
make the three steps more obvious.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-24 16:21:51 -07:00
Soren Brinkmann
5ce15d2d1e tty: xuartps: Print warning in clock notifier
Print a warning if the clock notifier rejects a clock frequency change
to facilitate debugging (see:
http://thread.gmane.org/gmane.linux.ports.arm.kernel/304329/focus=304379)

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-24 16:21:50 -07:00
Soren Brinkmann
e555a21149 tty: xuartps: Clean up
This is all white space and comment clean up. Mostly reformatting
comments.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-24 16:21:50 -07:00
Michal Simek
928e926349 tty: xuartps: Initialize ports according to aliases
Register port numbers according to order in DT aliases.
If aliases are not defined, order in DT is used.
If aliases are defined, register port id based
on that.
This patch ensures proper ttyPS0/1 assignment.

[soren]: Combined integer declarations in probe(), removed warning message
if no alias is found.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-24 16:21:50 -07:00
Michal Simek
489810a1a6 tty: xuartps: Fix kernel-doc errors in the driver
No functional changes.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-24 16:21:50 -07:00
Soren Brinkmann
c2db11eca0 tty: xuartps: Properly guard sysrq specific code
Commit 'tty: xuartps: Implement BREAK detection, add SYSRQ support'
(0c0c47bc40) introduced sysrq support
without properly guarding sysrq specific code which results in build
errors when sysrq is disabled:
	DNAME=KBUILD_STR(xilinx_uartps)" -c -o
	drivers/tty/serial/.tmp_xilinx_uartps.o
	drivers/tty/serial/xilinx_uartps.c
	drivers/tty/serial/xilinx_uartps.c: In function 'xuartps_isr':
	drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port'
	has no member named 'sysrq'
	drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port'
	has no member named 'sysrq'
	drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port'
	has no member named 'sysrq'
	make[3]: *** [drivers/tty/serial/xilinx_uartps.o] Error 1

Reported-by: Masanari Iida <standby24x7@gmail.com>
Cc: Vlad Lungu <vlad.lungu@windriver.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-17 16:02:25 -08:00
Soren Brinkmann
7ac57347c2 tty: xuartps: Fix build error when COMMON_CLK is not set
Clock notifiers are only available when CONFIG_COMMON_CLK is enabled.
Hence all notifier related code has to be protected by corresponsing
ifdefs.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29 09:26:11 -07:00
Soren Brinkmann
d3641f64bc tty: xuartps: Fix build error due to missing forward declaration
If CONFIG_PM_SLEEP is enabled and CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
is not, a forward declaration of the uart_driver struct is not
included, leading to a build error due to an undeclared variable.
Fixing this by moving the definition of the struct uart_driver before
the definition of the suspend/resume callbacks.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29 09:26:11 -07:00
Soren Brinkmann
d54b181ea6 tty: xuartps: Fix "may be used uninitialized" build warning
Initialize varibles for which a 'may be used uninitalized' warning is
issued.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29 09:26:11 -07:00
Soren Brinkmann
37cd940b20 tty: xuartps: Update copyright information
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:38 -07:00
Soren Brinkmann
4b47d9aa1e tty: xuartps: Implement suspend/resume callbacks
Implement suspend and resume callbacks in order to support system
suspend/hibernation.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:38 -07:00
Soren Brinkmann
c4b0510cc1 tty: xuartps: Dynamically adjust to input frequency changes
Add a clock notifier to dynamically handle frequency changes of the
input clock by reprogramming the UART in order to keep the baud rate
constant.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:38 -07:00
Soren Brinkmann
e6b39bfd0d tty: xuartps: Updating set_baud_rate()
The original algorithm to find the best baud rate dividers does not necessarily
find the best set of dividers. And in the worst case may even write illegal
values to the hardware.
The new function should make better use of the hardware capabilities and be able
to provide valid settings for a wider range of baud rates and also input clocks.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:38 -07:00
Lars-Peter Clausen
d3755f5e6c tty: xuartps: Force enable the UART in xuartps_console_write
It is possible that under certain circumstances xuartps_console_write is entered
while the UART disabled. When this happens the code will busy loop in
xuartps_console_putchar, since the character is never written and the TXEMPTY
flag is never set. The result is a system lockup. This patch force enables the
UART for the duration of xuartps_console_write to avoid this.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: John Linn <john.linn@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:38 -07:00
Suneel
85baf542d5 tty: xuartps: support 64 byte FIFO size
Changes to use the 64 byte FIFO depth and fix the issue
by clearing the txempty interrupt in isr status for tx
after filling in data in start_tx function

Signed-off-by: Suneel Garapati <suneelg@xilinx.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:37 -07:00