The original code looks as follows:
if (sport->dma_is_enabled) {
... make sure TX DMA is running, i.e. .dma_is_txing = 1
}
if (sport->dma_is_txing)
return;
As .dma_is_txing can only be true if .dma_is_enabled is, the return can
go at the end of the first if body without an additional check.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Neither .dma_is_txing nor .dma_is_rxing can evaluate to true if
.dma_is_enabled evaluates to false:
The only function that sets .dma_is_txing to a non-zero value is
imx_dma_tx() which is only called if .dma_is_enabled is true. Same for
.dma_is_rxing and start_rx_dma(). And before .dma_is_enabled is set to 0
when imx_shutdown calls imx_disable_dma(), .dma_is_rxing and
.dma_is_txing are reset to zero before, too.
For this reason
sport->dma_is_enabled && sport->dma_is_rxing
has the same value as
sport->dma_is_rxing
which allows to simplify three if conditions.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reduces the amount of read accesses to the register space by
shadowing the values for five registers that only change on writing
them. There is a single bit in UCR2 that might change without being
written to it, this is handled accordingly.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This prepares implementing shadow copies for the control registers and
additionally provides a good place to hook in debug code to trace
register usage.
Most of this patch was done using pattern substitution:
perl -p -i -e '
s/\breadl(?:_relaxed)?\((?:sport->port\.|port->)membase \+/imx_uart_readl(sport,/;
s/\bwritel(?:_relaxed)?\(([^,]*), (sport->port\.|port->)membase \+/imx_uart_writel(sport, $1,/;
' drivers/tty/serial/imx.c
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Consistently indicate being called with irqs off and the port lock taken
for all functions that this applies to.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Only the reference manual for the i.MX1 (I have MC9328MX1RM/D Rev 5 from
2004) uses TDMAEN and RDMAEN for these. All reference manuals for the
newer chips use TXDMAEN and RXDMAEN. Update to the newer name with the
assumption that most imx users don't use an imx1 any more.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The imx_ports[] array is indexed using a value derived from the
"serialN" alias in DT, or from platform data, which may lead to an
out-of-bounds access.
Fix this by adding a range check.
Fixes: ff05967a07 ("serial/imx: add of_alias_get_id() reference back")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
imx_shutdown() calls imx_disable_dma if .dma_is_enabled. So after
imx_shudown() completes, .dma_is_enabled is zero. For this reason
.dma_is_enabled is also zero when imx_startup() is called. So the check
for this variable being zero can be dropped.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The .dma_is_inited member is only set to a value != 0 when the port's
startup function calls imx_uart_dma_init(). On shutdown of the port
imx_uart_dma_exit is called which sets the value back to 0. So
.dma_is_inited is always 0 when imx_startup() is called (assuming
.startup() and .shutdown() are correctly balanced) and the check for
!sport->dma_is_inited can go away.
This allows to replace .dma_is_inited by a variable local to
imx_startup.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Handling an irq that isn't enabled can have some undesired side effects.
Some of these are mentioned in the newly introduced code comment. Some
of the irq sources already had their handling right, some don't. Handle
them all in the same consistent way.
The change for USR1_RRDY and USR1_AGTIM drops the check for
dma_is_enabled. This is correct as UCR1_RRDYEN and UCR2_ATEN are always
off if dma is enabled.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now the variable holding the value of register USR1 is called usr1
instead of sts which is more straight forward. The same is also done for
sts2 which is called usr2 now.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The check sts & USR1_DTRD was just evaluated to true two lines above.
So this change doesn't have any effect on the semantic of the driver.
Fixes: 27e1650105 ("serial: imx: implement DSR irq handling for DTE mode")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This allows me to login after sending a break when service
serial-getty@ttymxc0.service is running
The "tty_insert_flip_char(port, 0, TTY_BREAK)" in clear_rx_errors
fixes this by allowing the higher layers to see a break.
Also, call uart_handle_break to handle possible
"secure attention key."
FYI: Martin said the ROM sdma firmware works with this patch,
but external sdma firmware still does not send breaks on a
i.mx6UL
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Tested-by: Martin Hicks <mort@bork.org>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Before we go into suspend mode, we enable the imx uart's interrupt for
the awake bit in the UART Status Register 1. If, for some reason, the
awake bit is already set before we enter suspend mode, we get an
interrupt immediately when we enable interrupts for awake. The uart's
clk_ipg is disabled at this point (unless there's an ongoing transfer).
We end up in the interrupt handler, which usually tries to clear the
awake bit. This doesn't work with the clock disabled. Therefore, we
keep getting interrupts forever, resulting in an endless loop.
Clear the awake bit before setting the awaken bit to signal that we want
an imx interrupt when the awake bit will be set. This ensures that we're
not woken up by events that happened before we started going into
suspend mode.
Change the clock handling so that suspend prepares and enables the clock
and suspend_noirq disables it. Revert these operations in resume_noirq and
resume.
With these preparations in place, we can now modify awake and awaken in
the suspend function when the actual imx interrupt is disabled and the
required clk_ipg is active.
Update the thaw and freeze functions to use the new clock handling since
we share the suspend_noirq function between suspend and hibernate.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The wakeup mechanism via RTSDEN bit relies on the system using the RTS/CTS
lines, so only allow such wakeup method when the system actually has
RTS/CTS support.
Fixes: bc85734b12 ("serial: imx: allow waking up on RTSD")
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Martin Kaiser <martin@kaiser.cx>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Invoke the ->rs485_config callback on probe to adjust the initial RTS
polarity based on the UART's device properties.
This implicitly fixes a bug: If RTS control is not available, rs485
should be disabled even if it was enabled through a device property.
Log an error when that occurs.
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a driver invokes the uart_get_rs485_mode() helper, set the RTS
polarity to active high by default unless the newly introduced
"rs485-rts-active-low" property was specified.
imx contains a line to set the default RTS polarity to active high,
it is now superfluous and hence deleted.
omap-serial historically defaults to active low and supports an
"rs485-rts-active-high" property to inverse the polarity.
Retain that behavior for compatibility.
Cc: Mark Jackson <mpfj@newflow.co.uk>
Cc: Michał Oleszczyk <oleszczyk.m@gmail.com>
Cc: Rafael Gago Castano <rgc@hms.se>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit ef838a81dd ("serial: Add common rs485 device tree parsing
function") consolidated retrieval of rs485 OF properties in a common
helper function but did not #ifdef it to CONFIG_OF. The function is
therefore included on ACPI platforms as well even though it's not used.
On the other hand ACPI platforms with rs485 do exist (e.g. Siemens
IOT2040) and they may leverage _DSD to store rs485 properties. Likewise,
UART platform devices instantiated from an MFD should be able to specify
rs485 properties. In fact, the tty subsystem maintainer had asked for
a "generic" function during review of commit ef838a81dd4d:
https://marc.info/?l=linux-serial&m=150143441725194&w=4
Thus, instead of constraining the helper to OF platforms, make it
platform-agnostic by converting it to device_property_*() functions
and renaming it accordingly.
In imx.c, move the invocation of uart_get_rs485_mode() from
serial_imx_probe_dt() to serial_imx_probe() so that it also gets called
for non-OF devices.
In omap-serial.c, move its invocation further up within
serial_omap_probe_rs485() so that the RTS polarity can be overridden
with the driver-specific "rs485-rts-active-high" property once we
introduce a generic "rs485-rts-active-low" property.
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since imx_disable_rx_int is only called by imx_startup,
let's integrate it into that function. Notice UCR2_ATEN is
never set by the driver. The bit is still cleaned to make
this patch a noop.
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Acked-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that the SPDX tag is in all tty files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be removed as it is no longer needed at all.
This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.
No copyright headers or other non-license-description text was removed.
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Joachim Eastwood <manabian@gmail.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Alexander Shiyan <shc_work@mail.ru>
Cc: Baruch Siach <baruch@tkos.co.il>
Cc: Pat Gefre <pfg@sgi.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: Sylvain Lemieux <slemieux.tyco@gmail.com>
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: David Brown <david.brown@linaro.org>
Cc: "Andreas Färber" <afaerber@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Timur Tabi <timur@tabi.org>
Cc: Tony Prisk <linux@prisktech.co.nz>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.
Update the drivers/tty files files with the correct SPDX license
identifier based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.
This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Joachim Eastwood <manabian@gmail.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Alexander Shiyan <shc_work@mail.ru>
Cc: Baruch Siach <baruch@tkos.co.il>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: "Uwe Kleine-König" <kernel@pengutronix.de>
Cc: Pat Gefre <pfg@sgi.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: Sylvain Lemieux <slemieux.tyco@gmail.com>
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: David Brown <david.brown@linaro.org>
Cc: "Andreas Färber" <afaerber@suse.de>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Timur Tabi <timur@tabi.org>
Cc: Tony Prisk <linux@prisktech.co.nz>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 4dec2f119e ("imx-serial: RX DMA startup latency")
the interrupt routine no longer will start rx dma.
imx_dma_rxint no longer needs to be called to try and start dma.
It won't start dma because dma_is_rxing is
already true meaning dma is already started.
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 4dec2f119e ("imx-serial: RX DMA startup latency")
the interrupt routine no longer will start rx dma.
So, we no longer need to enable this interrupt to start dma.
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During hibernation, freeze/thaw/restore dev_pm_ops are called instead of
suspend/resume. Hook up the hibernation ops. The _noirq parts are
identical, but suspend/resume are replaced with variants that do not
enable wakeup from i.MX UART. There is no need to restore register
contents in thaw_noirq.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The comment in imx_flush_buffer() states that the state of 4 registers
are to be saved/restored, then only saves and restores 3 registers. The
missing register (UBRC) is read only and thus can't be restored.
Update the comment to reflect reality.
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The variable "dma_is_txing" is an unsigned int, set as either "0" or "1"
in all but one location, where it is instead set to "false". For
consistency, set dma_is_txing to "0" in this location too.
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The imx serial driver uses PAGE_SIZE when allocating rx_buf, but then
uses RX_BUF_SIZE (which is currently defined as PAGE_SIZE) to describe
the length of the buffer when initialising the scatter gather list.
In order to ensure that this stays consistent, use RX_BUF_SIZE in both
locations.
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Acked-by: Uwe Kleine-König <u.kleine-könig@pengtronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The variable dma_is_rxing is currently set to 1 in imx_disable_rx_int().
This is problematic as:
- whilst imx_disable_rx_int() is currently always called before
start_rx_dma() this dependency isn't obvious.
- start_rx_dma() does error checking and might exit without
enabling DMA. Currently this will result in dma_is_rxing suggesting
that DMA is being used for recieving.
To avoid these issues, move the setting of dma_is_rxing to
start_rx_dma() when appropriate.
Signed-off-by: Romain Perier <romain.perier@collabora.com>
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use setup_timer function instead of initializing timer with the
function and data fields.
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UART core function uart_update_mctrl relies on a cached value of
modem control lines. This was used but not updated by local RTS
control functions within imx.c. These are used for RS485 line
driver enable signalling. Having an out-of-date value in the cached
mctrl can result in the transmitter being enabled when it shouldn't
be.
Fix this by updating the mctrl value before applying it.
Signed-off-by: Ian Jamison <ian.dev@arkver.com>
Origin: id:8195c96e674517b82a6ff7fe914c7ba0f86e702b.1505375165.git.ian.dev@arkver.com
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds support for the rs485 specific properties defined in
Documentation/devicetree/bindings/serial/rs485.txt.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Forwarded: id:20170913081833.2740-7-u.kleine-koenig@pengutronix.de (v5)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The i.MX driver defaulted to full duplex rs485 which is rather
unusual and doesn't match the default implemented in other drivers.
So change the default to half duplex.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The imx_transmit_buffer function should return if TX DMA has already
been started and not just skip over the buffer PIO write loop. (Which
did fix the initial problem, but could have unintentional side-effects)
Tested on an i.MX6Q board with half-duplex RS-485 and with RS-232.
Cc: Clemens Gruber <clemens.gruber@pqgruber.com>
Cc: Uwe-Kleine König <u.kleine-koenig@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Fixes: 514ab34dba ("serial: imx: Prevent TX buffer PIO write when a DMA has been started")
Signed-off-by: Ian Jamison <ian.dev@arkver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If any key on console is pressed when board is suspended,
board hangs.
Driver's interrupt handler must be guaranteed not to run while
resume/suspend_noirq() are being executed. See include/linux/pm.h
for details.
Tested on i.MX6 based board.
The idea of this fix is based on commit in official i.MX kernel tree:
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git
commit 81e8e7d91d81 ("tty: serial: imx: disable irq after suspend")
Disable rx irq after suspend to avoid interrupt coming in early resume.
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Maxim Yu. Osipov <mosipov@ilbers.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The wait queue was only initialized and then checked if it contains
active jobs but a job is never added. The last real user was removed
with commit 9d297239b8 ("serial: imx-serial - update UART IMX driver
to use cyclic DMA").
Further there is no need to release the lock for the check if the port
should be woken up, (and IMHO there never was) so drop the unlock/lock
pair in dma_tx_callback(), too.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Function imx_transmit_buffer starts a TX DMA if DMA is enabled, since
commit 91a1a909f9 ("serial: imx: Support sw flow control in DMA mode").
It also carries on and attempts to write the same TX buffer using PIO.
This results in TX data corruption and double-incrementing xmit->tail
with the knock-on effect of tail passing head and a page of garbage
being sent out.
This seems to be triggered mostly when using RS485 half duplex on SMP
systems, but is probably not limited to just those.
Tested locally on an i.MX6Q with an RS485 half duplex transceiver on
UART3, and also by Clemens Gruber.
Tested-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Ian Jamison <ian.dev@arkver.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit a3015affdf as there
are complaints that it is incorrect.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Nandor Han <nandor.han@ge.com>
Cc: Romain Perier <romain.perier@collabora.com>
Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
The size of the DMA buffer can affect the delta time between data being
produced and data being consumed. Basically the DMA system will move
data to tty buffer when a) DMA buffer is full b) serial line is idle.
The situation is visible when producer generates data continuously and
there is no possibility for idle line. At this point the DMA buffer is
directly affecting the delta time.
The patch will add the possibility to configure the DMA buffers in DT,
which case by case can be configured separately for every driver
instance. The DT configuration is optional and in case missing the
driver will use the 4096 buffer with 4 periods (as before), therefore no
clients are impacted by this change.
Signed-off-by: Nandor Han <nandor.han@ge.com>
Signed-off-by: Romain Perier <romain.perier@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, this IRQ is always enabled. Some devices might mux these pins
to other I/Os, like I2C. This could lead to spurious interrupts.
This commit makes this IRQ optional, by using the field have_rtscts.
Signed-off-by: Nandor Han <nandor.han@ge.com>
Signed-off-by: Romain Perier <romain.perier@collabora.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
IRDA support is gone since commit afe9cbb1a6 ("serial: imx: drop
support for IRDA"), so remove the remaining irda members from
imx_port structure.
While at it, also remove 'trcv_delay' which is also unused.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit e61c38d85b ("serial: imx: setup DCEDTE early and ensure DCD and
RI irqs to be off") has a flaw: While UCR3 and UFCR were modified using
read-modify-write before it switched to write register values
independent of the previous state. That's a good idea in principle (and
that's why I did it) but needs more care.
This patch reinstates read-modify-write for UFCR and for UCR3 ensures
that RXDMUXSEL and ADNIMP are set for post imx1.
Fixes: e61c38d85b ("serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Mika Penttilä <mika.penttila@nextfour.com>
Tested-by: Mika Penttilä <mika.penttila@nextfour.com>
Acked-by: Steve Twiss <stwiss.opensource@diasemi.com>
Tested-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
18a4208 introduced a change to reduce the RX DMA latency on the first reception
when the serial port was opened for reading. However it was claiming a hardirq
unsafe lock after a hardirq safe lock which is not allowed and causes lockdep
to complain verbosely.
This patch changes the code to always start RX DMA earlier, instead of
relying on the flags used to open the serial port removing the code that
was looking for the serial file flags.
Signed-off-by: Peter Senna Tschudin <peter.senna@collabora.com>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reduce RX DMA start latency for the first reception when port is opened
for reading. Instead of waiting for an interrupt signaling data on RX
FIFO or data too old on RX FIFO, start RX DMA immediately when the
serial port is opened for reading.
Before this patch, the average RX DMA latency for the first reception
was 42489 microseconds with a standard deviation of 25721 microseconds
in 36 samples.
After the patch the average RX DMA latency for the first reception, when
the serial port is opened for reading, is 653 microseconds with a
standard deviation of 294 microseconds in 36 samples.
Signed-off-by: Peter Senna Tschudin <peter.senna@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the UART is operated in DTE mode and UCR3_DCD or UCR3_RI are 1 (which
is the reset default) and the opposite side pulls the respective line to
its active level the irq triggers after it is requested in .probe.
These irqs were already disabled in .startup but this might be too late.
Also setup of the UFCR_DCEDTE bit (currently done in .set_termios) is
done very late which is critical as it also controls direction of some
pins.
So setup UFCR_DCEDTE earlier (in .probe) and also disable the broken
irqs in DTE mode there before requesting irqs.
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When userspace passes the SER_RS485_RTS_ON_SEND flag it means that the
CTS_B pin should go to logic level high before the transmission begins.
CTS_B goes to logic level high when both CTSC and CTS bits are cleared.
When userspace passes the SER_RS485_RTS_AFTER_SEND flag it means that the
CTS_B pin should go to logic level low after the transmission finishes.
CTS_B goes to logic level low when CTSC bit is cleared and CTS bit is set.
So fix the CTS_B polarity logic.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On a board that needs to drive RTS GPIO high in order to enable the
transmission of a RS485 transceiver the following description is
passed in the devide tree:
&uart4 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart4>;
rts-gpios = <&gpio6 2 GPIO_ACTIVE_HIGH>;
status = "okay";
};
and userspace configures the uart port as follows:
/* enable RS485 mode: */
rs485conf.flags |= SER_RS485_ENABLED;
/* set logical level for RTS pin equal to 1 when sending: */
rs485conf.flags |= SER_RS485_RTS_ON_SEND;
/* set logical level for RTS pin equal to 0 after sending: */
rs485conf.flags &= ~(SER_RS485_RTS_AFTER_SEND);
However the RTS GPIO polarity observed in the oscilloscope is inverted.
When the SER_RS485_RTS_ON_SEND flag is set the imx_port_rts_active()
function should be called and following the same logic when
SER_RS485_RTS_AFTER_SEND flag is cleared the imx_port_rts_inactive()
should be called.
Do such logic change so that RS485 communication in half duplex can
work successfully when the RTS GPIO pin is passed via device tree.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
According to Documentation/devicetree/bindings/serial/serial.txt the
generic 'rts-gpios' property can be used to specify the GPIO for RTS
functionality.
Currently it is not possible to use the imx UART port in rs485 mode when
the 'rts-gpios' property is passed in the device tree.
The imx uart driver only checks for the presence of the built-in RTS pin,
via 'uart-has-rtscts' property and disable the rs485 flag if this property
is absent.
So fix this logic by also checking if RTS pin has been passed via GPIO.
Tested on a imx6dl based board.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Tested-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The USR2_DCDIN bit is tested for in register usr1. As the name
suggests the usr2 register should be used instead. This fixes
reading the Carrier detect status.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Fixes: 90ebc48386 ("serial: imx: repair and complete handshaking")
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: <stable@vger.kernel.org> # 4.5+
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Uwe Kleine-König