Use uart_console() helper in instead of open coded variant.
Note, SERIAL_CORE_CONSOLE is selected by SERIAL_ATMEL_CONSOLE,
thus no functional changes expected.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Link: https://lore.kernel.org/r/20200310133057.86840-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nothing in this driver uses the symbols from these GPIO
includes so drop them. These are probably just historical
artifacts from befor mctrl_gpio was used.
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Razvan Stefanescu <razvan.stefanescu@microchip.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200229220941.205599-1-linus.walleij@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In atmel_shutdown() we call atmel_stop_rx() and atmel_stop_tx() functions.
Prevent the rx restart that is implemented in RS485 or ISO7816 modes when
calling atmel_stop_tx() by using the atomic information tasklet_shutdown
that is already in place for this purpose.
Fixes: 98f2082c3a ("tty/serial: atmel: enforce tasklet init and termination sequences")
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200210152053.8289-1-nicolas.ferre@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At this moment, TXEMPTY is checked before sending data on RS485 and ISO7816
modes. However, TXEMPTY is risen when FIFO (if used) or the Transmit Shift
Register are empty, even though TXRDY might be up and controller is able to
receive data. Since the controller sends data only when TXEMPTY is ready,
on RS485, when DMA is not used, the RTS pin is driven low after each byte.
With this patch, the characters will be transmitted when TXRDY is up and
so, RTS pin will remain high between bytes.
The performance improvement on RS485 is about 8% with a baudrate of 300.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Link: https://lore.kernel.org/r/20200107111656.26308-1-codrin.ciubotariu@microchip.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.
While at it, remove forward-declaration of atmel_console - it wasn't
needed even at the moment the driver was first time introduced:
commit 1e6c9c2878 ("[ARM] 3242/2: AT91RM9200 support for 2.6 (Serial)")
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-13-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 751d001733.
The wrong commit got added to the tty-next tree, the correct one is in
the tty-linus branch.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Engraf <david.engraf@sysgo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use MCK_DIV8 when the clock divider is > 65535. Unfortunately the mode
register was already written thus the clock selection is ignored.
Fix by doing the baud rate calulation before setting the mode.
Fixes: 5bf5635ac1 ("tty/serial: atmel: add fractional baud rate support")
Signed-off-by: David Engraf <david.engraf@sysgo.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191216085403.17050-1-david.engraf@sysgo.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use MCK_DIV8 when the clock divider is > 65535. Unfortunately the mode
register was already written thus the clock selection is ignored.
Fix by writing the mode register after calculating the baudrate.
Signed-off-by: David Engraf <david.engraf@sysgo.com>
Link: https://lore.kernel.org/r/20191211162954.8393-1-david.engraf@sysgo.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 18dfef9c7f ("serial: atmel: convert to irq handling
provided mctrl-gpio"), the GPIOs interrupts are handled by
mctrl_gpio_irq_handle().
So, atmel_get_lines_status() can be completely killed and replaced by :
atmel_uart_readl(port, ATMEL_US_CSR);
Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Link: https://lore.kernel.org/r/20190826071752.30396-1-richard.genoud@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When half-duplex RS485 communication is used, after RX is started, TX
tasklet still needs to be scheduled tasklet. This avoids console freezing
when more data is to be transmitted, if the serial communication is not
closed.
Fixes: 69646d7a36 ("tty/serial: atmel: RS485 HD w/DMA: enable RX after TX is stopped")
Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190813074025.16218-1-razvan.stefanescu@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Variable ret is initialized to a value that is never read and it
is re-assigned later. The initialization is redundant and can be
removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20190809174042.6276-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In half-duplex operation, RX should be started after TX completes.
If DMA is used, there is a case when the DMA transfer completes but the
TX FIFO is not emptied, so the RX cannot be restarted just yet.
Use a boolean variable to store this state and rearm TX interrupt mask
to be signaled again that the transfer finished. In interrupt transmit
handler this variable is used to start RX. A warning message is generated
if RX is activated before TX fifo is cleared.
Fixes: b389f173aa ("tty/serial: atmel: RS485 half duplex w/DMA: enable
RX after TX is done")
Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use a helper function to check that a port needs to use half duplex
communication, replacing several occurrences of multi-line bit checking.
Fixes: b389f173aa ("tty/serial: atmel: RS485 half duplex w/DMA: enable RX after TX is done")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When mode is set in atmel_config_iso7816() we backup last RS232 mode
for coming back to this mode if requested.
Also allow setup of T=0 and T=1 parameter and basic support in set_termios
function as well.
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
[ludovic.desroches@microchip.com: rebase, add check on fidi ratio, checkpatch fixes]
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch modifies the place where resources and device tree properties
are searched.
Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
I was puzzled while looking at /proc/interrupts and random things showed
up between reboots. This occurred more often but I realised it later. The
"correct" output should be:
|38: 11861 atmel-aic5 2 Level ttyS0
but I saw sometimes
|38: 6426 atmel-aic5 2 Level tty1
and accounted it wrongly as correct. This is use after free and the
former example randomly got the "old" pointer which pointed to the same
content. With SLAB_FREELIST_RANDOM and HARDENED I even got
|38: 7067 atmel-aic5 2 Level E=Started User Manager for UID 0
or other nonsense.
As it turns out the tty, pointer that is accessed in atmel_startup(), is
freed() before atmel_shutdown(). It seems to happen quite often that the
tty for ttyS0 is allocated and freed while ->shutdown is not invoked. I
don't do anything special - just a systemd boot :)
Use dev_name(&pdev->dev) as the IRQ name for request_irq(). This exists
as long as the driver is loaded so no use-after-free here.
Cc: stable@vger.kernel.org
Fixes: 761ed4a945 ("tty: serial_core: convert uart_close to use tty_port_close")
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On our at91sam9260 based board the usart0 and usart1 ports report
their versions (ATMEL_US_VERSION) as 0x10302. This version is not
included in the current checks in the driver.
Signed-off-by: Jonas Danielsson <jonas@orbital-systems.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: stable <stable@vger.kernel.org>
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 ef838a81dd:
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>
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>
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The atmel serial port driver reported the following warning on suspend:
atmel_usart f8020000.serial: ttyS1: Unable to drain transmitter
As the ATMEL_US_TXEMPTY status bit in ATMEL_US_CSR is always cleared
when the transmitter is disabled, we need to know the transmitter's
state to return the real fifo state. And as ATMEL_US_CR is write-only,
it is necessary to save the state of the transmitter in a local
variable, and update the variable when TXEN and TXDIS is written in
ATMEL_US_CR.
After those changes, atmel_tx_empty can return "empty" on suspend, the
warning in uart_suspend_port disappears, and suspending is 20ms shorter
for each enabled Atmel serial port.
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Tested-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We just got a common helper for parsing the rs485 specific
device tree properties. Use it and drop the open coded parser.
Note that there is a small difference between the removed and the now
used implementation: The former cleared flags to 0 if rs485-rts-delay
was given, the common helper clears SER_RS485_RX_DURING_TX and
SER_RS485_ENABLED only but always which makes more sense.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
[ukleinek: point out semantic change in commit log]
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that AVR32 is gone, platform_data are not used to initialize the driver
anymore, remove that path from the driver. Also remove the now unused
struct atmel_uart_data.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
atmel_default_console_device was only used by AVR32, in particular
arch/avr32/mach-at32ap/at32ap700x.c which is now gone. Remove it from the
driver.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
AVR32 is gone. Now it's time to clean up the driver by removing
leftovers that was used by AVR32 related code.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A side effect of 89d8232411 ("tty/serial: atmel_serial: BUG: stop DMA
from transmitting in stop_tx") is that the console can be called with
TX path disabled. Then the system would hang trying to push charecters
out in atmel_console_putchar().
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Fixes: 89d8232411 ("tty/serial: atmel_serial: BUG: stop DMA from transmitting
in stop_tx")
Cc: stable <stable@vger.kernel.org> #4.4+
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If uart_flush_buffer() is called between atmel_tx_dma() and
atmel_complete_tx_dma(), the circular buffer has been cleared, but not
atmel_port->tx_len.
That leads to a circular buffer overflow (dumping (UART_XMIT_SIZE -
atmel_port->tx_len) bytes).
Tested-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org> # 3.12+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
atmel_serial.h is only used by atmel_serial.c, so there's no need for
it to lie in include/linux.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
struct cache is only used in suspend/resume. Exclude it when PM is not
selected.
Suggested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The samx7 family uses the same UART/USART IP as the at91/sama5 families but
has 8 of those.
Suggested-by: Szemző András <sza@esh.hu>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The fractional baud rate generator is available when using the
asynchronous mode of Atmel USART controllers. It makes it possible to
use higher baudrates, in exchange for a less precise clock with a
variable duty cycle.
The existing code restricts its use to the normal mode of the USART
controller, following the recommendation from the datasheet for the
first chip embedding this type of controller. This recommendation has
been removed from the documentation for the newer chips. After
verification, all revisions of this controller should be able to use the
fractional baud rate generator with the different asynchronous modes.
Removing the condition on ATMEL_US_USMODE makes it possible to get
correct baudrates at high speed in more cases.
This was tested with a board using an Atmel SAMA5D2 chip and a TI
WL1831 WiFi/Bluetooth combo chip at 3 Mbauds, with hardware flow control
enabled.
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When going to suspend, the UART registers may be lost because the power to
VDDcore is cut. This is not an issue in the normal case but when
no_console_suspend is used, we need to restore the registers in order to
get a functional console.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Reviewed-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When using RS485 in half duplex, RX should be enabled when TX is
finished, and stopped when TX starts.
Before commit 0058f0871e ("tty/serial: atmel: fix RS485 half
duplex with DMA"), RX was not disabled in atmel_start_tx() if the DMA
was used. So, collisions could happened.
But disabling RX in atmel_start_tx() uncovered another bug:
RX was enabled again in the wrong place (in atmel_tx_dma) instead of
being enabled when TX is finished (in atmel_complete_tx_dma), so the
transmission simply stopped.
This bug was not triggered before commit 0058f0871e
("tty/serial: atmel: fix RS485 half duplex with DMA") because RX was
never disabled before.
Moving atmel_start_rx() in atmel_complete_tx_dma() corrects the problem.
Cc: stable@vger.kernel.org
Reported-by: Gil Weber <webergil@gmail.com>
Fixes: 0058f0871e
Tested-by: Gil Weber <webergil@gmail.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If we don't disable the transmitter in atmel_stop_tx, the DMA buffer
continues to send data until it is emptied.
This cause problems with the flow control (CTS is asserted and data are
still sent).
So, disabling the transmitter in atmel_stop_tx is a sane thing to do.
Tested on at91sam9g35-cm(DMA)
Tested for regressions on sama5d2-xplained(Fifo) and at91sam9g20ek(PDC)
Cc: <stable@vger.kernel.org> (beware, this won't apply before 4.3)
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After commit 1cf6e8fc83 ("tty/serial: at91: fix RTS line management
when hardware handshake is enabled"), the hardware handshake wasn't
functional anymore on Atmel platforms (beside SAMA5D2).
To understand why, one has to understand the flag ATMEL_US_USMODE_HWHS
first:
Before commit 1cf6e8fc83 ("tty/serial: at91: fix RTS line management
when hardware handshake is enabled"), this flag was never set.
Thus, the CTS/RTS where only handled by serial_core (and everything
worked just fine).
This commit introduced the use of the ATMEL_US_USMODE_HWHS flag,
enabling it for all boards when the user space enables flow control.
When the ATMEL_US_USMODE_HWHS is set, the Atmel USART controller
handles a part of the flow control job:
- disable the transmitter when the CTS pin gets high.
- drive the RTS pin high when the DMA buffer transfer is completed or
PDC RX buffer full or RX FIFO is beyond threshold. (depending on the
controller version).
NB: This feature is *not* mandatory for the flow control to work.
(Nevertheless, it's very useful if low latencies are needed.)
Now, the specifics of the ATMEL_US_USMODE_HWHS flag:
- For platforms with DMAC and no FIFOs (sam9x25, sam9x35, sama5D3,
sama5D4, sam9g15, sam9g25, sam9g35)* this feature simply doesn't work.
( source: https://lkml.org/lkml/2016/9/7/598 )
Tested it on sam9g35, the RTS pins always stays up, even when RXEN=1
or a new DMA transfer descriptor is set.
=> ATMEL_US_USMODE_HWHS must not be used for those platforms
- For platforms with a PDC (sam926{0,1,3}, sam9g10, sam9g20, sam9g45,
sam9g46)*, there's another kind of problem. Once the flag
ATMEL_US_USMODE_HWHS is set, the RTS pin can't be driven anymore via
RTSEN/RTSDIS in USART Control Register. The RTS pin can only be driven
by enabling/disabling the receiver or setting RCR=RNCR=0 in the PDC
(Receive (Next) Counter Register).
=> Doing this is beyond the scope of this patch and could add other
bugs, so the original (and working) behaviour should be set for those
platforms (meaning ATMEL_US_USMODE_HWHS flag should be unset).
- For platforms with a FIFO (sama5d2)*, the RTS pin is driven according
to the RX FIFO thresholds, and can be also driven by RTSEN/RTSDIS in
USART Control Register. No problem here.
(This was the use case of commit 1cf6e8fc83 ("tty/serial: at91: fix
RTS line management when hardware handshake is enabled"))
NB: If the CTS pin declared as a GPIO in the DTS, (for instance
cts-gpios = <&pioA PIN_PB31 GPIO_ACTIVE_LOW>), the transmitter will be
disabled.
=> ATMEL_US_USMODE_HWHS flag can be set for this platform ONLY IF the
CTS pin is not a GPIO.
So, the only case when ATMEL_US_USMODE_HWHS can be enabled is when
(atmel_use_fifo(port) &&
!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS))
Tested on all Atmel USART controller flavours:
AT91SAM9G35-CM (DMAC flavour), AT91SAM9G20-EK (PDC flavour),
SAMA5D2xplained (FIFO flavour).
* the list may not be exhaustive
Cc: <stable@vger.kernel.org> #4.4+ (beware, missing atmel_port variable)
Fixes: 1cf6e8fc83 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled")
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The problem with previous code was it rounded values in wrong
place and produced wrong baud rate in some cases.
Signed-off-by: Alexey Starikovskiy <aystarik@gmail.com>
[nicolas.ferre@atmel.com: port to newer kernel and add commit log]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 18dfef9c7f ("serial: atmel: convert to irq handling
provided mctrl-gpio"), interrupts from GPIOs are not disabled any more
when the serial port is closed, leading to an oops when the one of the
input pin is toggled (CTS/DSR/DCD/RNG).
This is only the case if those pins are used as GPIOs, i.e. declared
like that:
usart1: serial@f8020000 {
/* CTS and DTS will be handled by GPIO */
status = "okay";
rts-gpios = <&pioB 17 GPIO_ACTIVE_LOW>;
cts-gpios = <&pioB 16 GPIO_ACTIVE_LOW>;
dtr-gpios = <&pioB 14 GPIO_ACTIVE_LOW>;
dsr-gpios = <&pioC 31 GPIO_ACTIVE_LOW>;
rng-gpios = <&pioB 12 GPIO_ACTIVE_LOW>;
dcd-gpios = <&pioB 15 GPIO_ACTIVE_LOW>;
};
That's because modem interrupts used to be freed in atmel_shutdown().
After commit 18dfef9c7f ("serial: atmel: convert to irq handling
provided mctrl-gpio"), this code was just removed.
Calling atmel_disable_ms() disables the interrupts and everything works
fine again.
Tested on at91sam9g35-cm
(This patch doesn't apply on -stable kernels, fixes for 4.4 and 4.7 will
be sent after this one is applied.)
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Fixes: 18dfef9c7f ("serial: atmel: convert to irq handling provided mctrl-gpio")
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use of_property_read_bool to check for the existence of a property.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression e1,e2;
statement S2,S1;
@@
- if (of_get_property(e1,e2,NULL))
+ if (of_property_read_bool(e1,e2))
S1 else S2
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The USART device provides a fractional baud rate generator to get a more
accurate baud rate. It can be used only when the USART is configured in
'normal mode' and this feature is not available on AT91RM9200 SoC.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As some race conditions are identified in the termination process of tasklets,
enforce the atmel_shutdown() sequence. This way we make sure that no new
tasklets or software timer are scheduled during shutdown process.
An atomic flag is positioned to give this information throughout the code.
We also remove tasklet_disable() calls that were leading to deadlocks while
stopping the driver. A simpler init/kill sequence is used.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When using DMA, half duplex doesn't work properly because rx is not stopped
before starting tx. Ensure we call atmel_stop_rx() in the DMA case.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a macro named ATMEL_SERIAL_RINGSIZE which suggesting that it
corresponds to the real size of the ring buffer. Let warn people that
there is a factor of four since allocation size is
sizeof(struct atmel_uart_char) * ATMEL_SERIAL_RINGSIZE.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Split TX and RX paths to not schedule RX tasklet on TX events and vice versa.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The IRQ status check and related actions was done in the tasklet without
benefit. So, move it back to the IRQ context to simplify IRQ handling and
having the possibility to split the tasklet in two separated ones for
receive and transmit actions.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 1cf6e8fc83 ("tty/serial: at91: fix RTS line management when
hardware handshake is enabled") actually allowed to enable hardware
handshaking.
Before, the CRTSCTS flags was silently ignored.
As the DMA controller can't drive RTS (as explain in the commit message).
Ensure that hardware flow control stays disabled when DMA is used and FIFOs
are not available.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Fixes: 1cf6e8fc83 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled")
Cc: stable <stable@vger.kernel.org> # v4.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With SAMA5D2, the UART has hw timeout but the offset of the register to
define this value is not the same as the one for USART.
When using the new UART, the value of this register was 0 so we never
get timeout irqs. It involves that when using DMA, we were stuck until
the execution of the dma callback which happens when a buffer is full
(so after receiving 2048 bytes).
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit c39dfebc77, the modular support
code for atmel_serial was removed, as the driver cannot be built as a
module. Because no use case was proposed, the dynamic driver binding
support was removed as well.
The atmel_serial driver can manage up to 7 serial controllers, which are
multiplexed with other functions. For example, in the Atmel SAMA5D2, the
Flexcom controllers can work as USART, SPI or I2C controllers, and on
all Atmel devices serial lines can be reconfigured as GPIOs.
My use case uses GPIOs to transfer a firmware update using a custom
protocol on the lines used as a serial port during the normal life of
the device. If it is not possible to unbind the atmel_serial driver, the
GPIO lines remain reserved and prevent this case from working.
This patch reinstates the atmel_serial_remove function, and fixes it as
it failed to clear the "clk" field on removal, triggering an oops when
a device was bound again after being unbound.
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In all functions other than atmel_serial_probe_fifos,
atmel_serial_probe, and atmel_console_init, the name "port" is used to
refer to an instance of struct uart_port. In many of these functions,
"atmel_port" is used to refer to an instance of struct atmel_uart_port.
We make the use of the name "port" consistent by making
atmel_serial_probe_fifos, atmel_serial_probe, and atmel_console_init
use "atmel_port" to refer to an instance of struct atmel_uart_port
instead of the previous name of "port".
Signed-off-by: Jaeden Amero <jaeden.amero@ni.com>
Signed-off-by: Kyle Roeschley <kyle.roeschley@ni.com>
Acked-by: Karthik Manamcheri <karthik.manamcheri@ni.com>
[nicolas.ferre@atmel.com: fix typo in variable, adapt to newer kernel]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Starting with sama5d2, the new UART revision has an hardware timer. So, add it
to the IP detection code and set the "has_hw_timer" property for it.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Reported-by: David Mosberger <davidm@egauge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No functional change is associated with this patch.
A driver property depends on the Atmel serial IP revision. This property
is the way the rx timeout is handled: by an hardware or software timer.
So, change this property name and setup code so that it's easier to understand
and more future proof as the distinction of USART vs. UART is blurrier on newer
SoCs.
Variable names and debug comments are also adapted to make this code more obvious.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit c39dfebc77 ("drivers/tty/serial:
make serial/atmel_serial.c explicitly non-modular") we removed the code
relating to modular support since it currently only supports built in.
However, when redoing my build coverage for mips allmodconfig, which
sets CONFIG_OF, I noticed a remaining line that needs to be removed,
else we will get a build failure for an undefined module macro.
Unfortunately this didn't appear for any of the other arch I tested
more frequently, such as ARM.
Since MODULE_DEVICE_TABLE is a no-op for non-modular code, we can just
remove the offending line.
Fixes: c39dfebc77 ("drivers/tty/serial: make serial/atmel_serial.c explicitly non-modular")
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jiri Slaby <jslaby@suse.com>
Reported-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Kconfig currently controlling compilation of this code is:
drivers/tty/serial/Kconfig:config SERIAL_ATMEL
drivers/tty/serial/Kconfig: bool "AT91 / AT32 on-chip serial port support"
...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.
We explicitly disallow a driver unbind, since that doesn't have a
sensible use case anyway, and it allows us to drop the ".remove"
code for non-modular drivers.
Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.
We don't replace module.h with init.h since the file already has that.
We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a misplaced bracket in atmel_init_rs485 which sets
rs485-rx-during-tx and rs485-enabled-at-boot-time only if
rs485-rts-delay is set in of.
This is clearly a bug, so fix it by moving the bracket to the proper
place.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Elen Song <elen.song@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Turning on KVM and LPAE support on top of a multi_v7_defconfig will
produce a compiler warning in the Atmel serial driver:
drivers/tty/serial/atmel_serial.c: In function 'atmel_verify_port':
drivers/tty/serial/atmel_serial.c:2299:6: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
if ((void *)port->mapbase != ser->iomem_base)
^
Fix that by using the cast on the right hand side instead, as similar
code already does in other drivers.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We want the tty fixes and reverts in here as well so that people can
properly test and use it.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If atmel_init_gpios fails the port has already been marked as busy (in
line 2629), so this must be undone in the error path.
This bug was introduced because I created the patch that finally
became 722ccf416a ("serial: atmel: fix error handling when
mctrl_gpio_init fails") on top of 3.19 which didn't have commit
6fbb9bdf0f ("tty/serial: at91: fix error handling in
atmel_serial_probe()") yet.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Fixes: 722ccf416a ("serial: atmel: fix error handling when mctrl_gpio_init fails")
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is done before adding more functionality to the init function with
the existing name. As this new functionality conflicts with stuff
drivers are required to implement themselves up to I want to convert
them one by one to make reviewing and reverting more easy in case I
broke something.
Once mctrl_gpio_init is there and all drivers are converted
mctrl_gpio_init_noauto can be removed again.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit also fixes compiler warnings and errors seen when building
on x86_64.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move ATMEL_MAX_UART from platform_data/atmel.h to atmel_serial.c as this is
the only file using it and it is common practise from tty/serial drivers to
define it directly in the driver file.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes I/O accesses on the Receiver Holding Register and on the
Transmitter Holding Register. Indeed AVR32 can only perform 32bit I/O
accesses on registers: using 8bit I/O accesses would read or write garbage
data.
Fixes: commit b5199d4681 ("tty/serial: at91: add support to FIFOs")
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For now this improvement is only used with TX DMA transfers. The data
width must be set properly when configuring the DMA controller. Also
the FIFO configuration must be set to match the DMA transfer data
width:
TXRDYM (Transmitter Ready Mode) and RXRDYM (Receiver Ready Mode) must
be set into the FIFO Mode Register. These values are used by the
USART to trigger the DMA controller. In single data mode they are not
used and should be reset to 0.
So the TXRDYM bits are changed to FOUR_DATA; then USART triggers the
DMA controller when at least 4 data can be written into the TX FIFO
througth the THR. On the other hand the RXRDYM bits are left unchanged
to ONE_DATA.
Atmel eXtended DMA controller allows us to set a different data width
for each part of a scatter-gather transfer. So when calling
dmaengine_slave_config() to configure the TX path, we just need to set
dst_addr_width to the maximum data width. Then DMA writes into THR are
split into up to two parts. The first part carries the first data to
be sent and has a length equal to the greatest multiple of 4 (bytes)
lower than or equal to the total length of the TX DMA transfer. The
second part carries the trailing data (up to 3 bytes). The first part
is written by the DMA into THR using 32 bit accesses, whereas 8bit
accesses are used for the second part.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Depending on the hardware, TX and RX FIFOs may be available. The RX
FIFO can avoid receive overruns, especially when DMA transfers are
not used to read data from the Receive Holding Register. For heavy
system load, The CPU is likely not be able to fetch data fast enough
from the RHR.
In addition, the RX FIFO can supersede the DMA/PDC to control the RTS
line when the Hardware Handshaking mode is enabled. Two thresholds
are to be set for that purpose:
- When the number of data in the RX FIFO crosses and becomes lower
than or equal to the low threshold, the RTS line is set to low
level: the remote peer is requested to send data.
- When the number of data in the RX FIFO crosses and becomes greater
than or equal to the high threshold, the RTS line is set to high
level: the remote peer should stop sending new data.
- low threshold <= high threshold
Once these two thresholds are set properly, this new feature is
enabled by setting the FIFO RTS Control bit of the FIFO Mode Register.
FIFOs also introduce a new multiple data mode: the USART works either
in multiple data mode or in single data (legacy) mode.
If MODE9 bit is set into the Mode Register or if USMODE is set to
either LIN_MASTER, LIN_SLAVE or LON_MODE, FIFOs operate in single
data mode. Otherwise, they operate in multiple data mode.
In this new multiple data mode, accesses to the Receive Holding
Register or Transmit Holding Register slightly change.
Since this driver implements neither the 9bit data feature (MODE9 bit
set into the Mode Register) nor LIN modes, the USART works in
multiple data mode whenever FIFOs are available and enabled. We also
assume that data are 8bit wide.
In single data mode, 32bit access CAN be used to read a single data
from RHR or write a single data into THR.
However in multiple data mode, a 32bit access to RHR now allows us to
read four consecutive data from RX FIFO. Also a 32bit access to THR
now allows to write four consecutive data into TX FIFO. So we MUST
use 8bit access whenever only one data have to be read/written at a
time.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch replaces the UART_PUT_*, resp. UART_GET_*, macros by
atmel_uart_writel(), resp. atmel_uart_readl(), inline function calls.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In RS485 mode, we may want to set the delay_rts_after_send value to 0.
In the datasheet, the 0 value is said to "disable" the Transmitter Timeguard but
this is exactly the expected behavior if we want no delay...
Moreover, if the value was set to non-zero value by device-tree or earlier
ioctl command, it was impossible to change it back to zero.
Reported-by: Sami Pietikäinen <Sami.Pietikainen@wapice.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: stable@vger.kernel.org # 3.2+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Handle the changed flag of IRQ status in interruption
instead of handling it in tasklet due to the tasklet
may be scheduled more than once in one interruption.
Otherwise, the changed status may be processed more
than once which will lead to unexpected result. And
seriously, kernel will crash.
Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Maxburst was not set when doing the dma slave configuration. This value
is checked by the recently introduced xdmac. It causes an error when
doing the slave configuration and so prevents from using dma.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Cc: <stable@vger.kernel.org> # 3.12 and later
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The tasklet may be scheduled and executed after serial port
was shutdown, for example, DMA rx callback will schedule the
tasklet while serial port is shutting down, especially serial
port is sending and receiving data in a higher baud rate and
it's killed by external program. In this case, tasklet_kill
can only clear the current scheduling out, so tasklet should
be disabled to prevent being executed in later scheduling.
Otherwise, the tasklet executed after serial port was shutdown
can lead to kernel crash.
Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The property in device tree will be reading each time when tty is opened,
so the ops of serial port should be set after that instead of setting once
in probe. Otherwise, the ops of serial port is inconsistent with the state
of serial work manner. For example, the atmel serial driver can't work when
switching to PIO mode due to DMA channel is not available.
Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The function of atmel_init_property is to set the work manner of
atmel serial ports according to the property in device trees.
If DMA or PDC is not set or something goes wrong in getting property,
the work manner will switch to general PIO mode, thus there will
not be any failure case in this function. It's actually a procedure.
So changing the return type from int to void.
Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The buffer size set in DMA is inconsistent with its allocation.
So keep them consistent here. The structure atmel_uart_char is
used in PIO mode with its meaning. But here in DMA, all of the
buffer is treated as general char.
Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We only use buf of ring In DMA rx function while using buf of xmit
in DMA tx function. So in DMA rx we need definitively to check the
buf of ring which is corresponding to DMA rx function. And use macro
PAGE_ALIGNED to simplify the expression.
Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mctrl_gpio_init at present doesn't return NULL. (It might be used in the
future when no gpios are to be used indicating success.) Properly pass
error returned and also make driver probing fail on error.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The IRQ line connected to the DBGU UART is often shared with a timer device
which request the IRQ with IRQF_NO_SUSPEND.
Since the UART driver is correctly disabling IRQs when entering suspend
we can safely request the IRQ with IRQF_COND_SUSPEND so that irq core
will not complain about mixing IRQF_NO_SUSPEND and !IRQF_NO_SUSPEND.
Rework the interrupt handler to wake the system up when an interrupt
happens on the DEBUG_UART while the system is suspended.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch fixes many bugs in the code dealing with the hardware handshake.
As an example, in atmel_set_termios(), we used to test whether the CRTSCTS
c_cflag was set. If so, we selected the "Hardware Handshake" mode through the
Mode Register. However, few lines below the mode was reset to "Normal" (0).
So there was no way to select the "Hardware Handshake" mode. To fix this issue,
we moved the CRTSCRTS c_cflag test AFTER the mode has been reset to "Normal".
Also setting the RTSEN and RTSDIS bits in the Control Register has different
results whether the USART is set in "Normal" or "Hardware Handshake" mode:
1) "Normal" mode
- the RTSEN bit forces the RTS line to low level, which tells the remote peer
that we are ready to received new data.
- the RTSDIS bit forces the RTS line to high level, which tells the remote peer
to stop sending new data.
2) "Hardware Handshake" mode
- the RTSEN bit forces the RTS line to high level.
- the RTSDIS bit lets the hardware control the RTS line.
WARNING:
when FIFOs are not available or not enabled, the RTS line is controlled by the
PDC. This is why using the Hardware Handshake mode requires using the PDC
channel for reception. However the Hardware Handshake mode DOES NOT work with
DMA controller since it cannot control the RTS line.
Future designs with FIFOs will introduce a new feature: the RTS line will be
controlled by the RX FIFO using thresholds. This patch was tested with this new
design.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-EDEFER error wasn't handle properly by atmel_serial_probe().
As an example, when atmel_serial_probe() is called for the first time, we pass
the test_and_set_bit() test to check whether the port has already been
initalized. Then we call atmel_init_port(), which may return -EDEFER, possibly
returned before by clk_get(). Consequently atmel_serial_probe() used to return
this error code WITHOUT clearing the port bit in the "atmel_ports_in_use" mask.
When atmel_serial_probe() was called for the second time, it used to fail on
the test_and_set_bit() function then returning -EBUSY.
When atmel_serial_probe() fails, this patch make it clear the port bit in the
"atmel_ports_in_use" mask, if needed, before returning the error code.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: <stable@vger.kernel.org> # 3.12+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
atmel_serial_probe() calls atmel_init_port(). In turn, atmel_init_port() calls
clk_disable_unprepare() to disable the peripheral clock before returning.
Later atmel_serial_probe() accesses some I/O registers such as the Mode and
Control registers for RS485 support then the Name and Version registers, through a call to
atmel_get_ip_name(), but at that moment the peripheral clock was still
disabled.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: <stable@vger.kernel.org> # 3.12+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes, just
removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There are
some ath9k patches coming in through this tree that have been acked by
the wireless maintainers as they relied on the debugfs changes.
Everything has been in linux-next for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core update from Greg KH:
"Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes,
just removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There
are some ath9k patches coming in through this tree that have been
acked by the wireless maintainers as they relied on the debugfs
changes.
Everything has been in linux-next for a while"
* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
fs: debugfs: add forward declaration for struct device type
firmware class: Deletion of an unnecessary check before the function call "vunmap"
firmware loader: fix hung task warning dump
devcoredump: provide a one-way disable function
device: Add dev_<level>_once variants
ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
ath: use seq_file api for ath9k debugfs files
debugfs: add helper function to create device related seq_file
drivers/base: cacheinfo: remove noisy error boot message
Revert "core: platform: add warning if driver has no owner"
drivers: base: support cpu cache information interface to userspace via sysfs
drivers: base: add cpu_device_create to support per-cpu devices
topology: replace custom attribute macros with standard DEVICE_ATTR*
cpumask: factor out show_cpumap into separate helper function
driver core: Fix unbalanced device reference in drivers_probe
driver core: fix race with userland in device_add()
sysfs/kernfs: make read requests on pre-alloc files use the buffer.
sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
fs: sysfs: return EGBIG on write if offset is larger than file size
...
Introduce an homogeneous lock system between setting and using the rs485
data of the uart_port.
This patch should not be split into multiple ones in order to avoid
leaving the tree in an unstable state.
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Suggested-by: Alan Cox <alan@linux.intel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In order to unify all the rs485 ioctl handling.
Use the implementation of TIOC[GS]RS485 ioctl handling on serial_core.
Reviewed-by: Alan Cox <alan@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Switching to the N_PPS line discipline may require enabling
modem status interrupts; conversely switching from N_PPS may
require disabling modem status interrupts.
Affected drivers:
8250
amba-pl010
atmel
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Three UART drivers (8250, atmel & amba-pl010) directly call their
enable_ms() method; the uart port lock must be acquired before
any h/w programming.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UART drivers which enable modem status interrupts when switching
to N_PPS line discipline need to determine if modem status
interrupts should be disabled when switching from N_PPS.
Specifically, the set_ldisc() notification needs to evaluate
UART_ENABLE_MS() which requires termios->c_cflag.
Convert in-tree UART drivers to new interface.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We are removing the dmaengine_device_control API, that shouldn't even have been
exposed in the first place. Change the callers to use the proper API.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch swaps the use "tail" and "head" to fit the semantic of the linux
circular buffer documentation:
- head: the point at which the producer (the DMA controller) inserts items.
- tail: the point at which the consumer (the serial framework) finds the next
item.
Besides the former code of the rx ring buffer didn't manage the case where
head < tail, which might lead to loss of data. To fix this bug the data are now
sent from the DMA buffer to the serial framework in two steps:
1 - First, we test if head < tail. If so, we copy the data from tail to the end
of the DMA buffer then reset tail to zero.
2 - Finally, we copy data from tail to head then set tail to head.
In addition, since tty_insert_flip_string() may now be called twice,
atmel_flip_buffer_rx_dma() becomes less efficient than moving the calls
dma_sync_sg_for_cpu(), dma_sync_sg_for_device(), tty_insert_flip_string() and
tty_flip_buffer_push() directly into atmel_rx_from_dma().
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the context of the final tty & port close, flushing the tx
ring buffer after the hardware has already been shutdown and
the ring buffer freed is neither required nor desirable.
uart_flush_buffer() performs 3 operations:
1. Resets tx ring buffer indices, but the tx ring buffer has
already been freed and the indices are reset if the port is
re-opened.
2. Calls uart driver's flush_buffer() method
5 in-tree uart drivers define flush_buffer() methods:
amba-pl011, atmel-serial, imx, serial-tegra, timbuart
These have been refactored into the shutdown() method, if
required.
3. Kicks the ldisc for more writing, but this is undesirable.
The file handle is being released; any waiting writer will
will be kicked out by tty_release() with a warning. Further,
the N_TTY ldisc may generate SIGIO for a file handle which
is no longer valid.
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull slave-dmaengine updates from Vinod Koul:
"For dmaengine contributions we have:
- designware cleanup by Andy
- my series moving device_control users to dmanegine_xxx APIs for
later removal of device_control API
- minor fixes spread over drivers mainly mv_xor, pl330, mmp, imx-sdma
etc"
* 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (60 commits)
serial: atmel: add missing dmaengine header
dmaengine: remove FSLDMA_EXTERNAL_START
dmaengine: freescale: remove FSLDMA_EXTERNAL_START control method
carma-fpga: move to fsl_dma_external_start()
carma-fpga: use dmaengine_xxx() API
dmaengine: freescale: add and export fsl_dma_external_start()
dmaengine: add dmaengine_prep_dma_sg() helper
video: mx3fb: use dmaengine_terminate_all() API
serial: sh-sci: use dmaengine_terminate_all() API
net: ks8842: use dmaengine_terminate_all() API
mtd: sh_flctl: use dmaengine_terminate_all() API
mtd: fsmc_nand: use dmaengine_terminate_all() API
V4L2: mx3_camer: use dmaengine_pause() API
dmaengine: coh901318: use dmaengine_terminate_all() API
pata_arasan_cf: use dmaengine_terminate_all() API
dmaengine: edma: check for echan->edesc => NULL in edma_dma_pause()
dmaengine: dw: export probe()/remove() and Co to users
dmaengine: dw: enable and disable controller when needed
dmaengine: dw: always export dw_dma_{en,dis}able
dmaengine: dw: introduce dw_dma_on() helper
...
The atmel serial driver uses dmaengine APIs but never included the dmaengine
header as it was getting inculded thru one of driver headers.
commit 3d588f83e4 - "dmaengine: dw: split
dma-dw.h to platform and private parts" broke this as it moved headers
around. Fix this by doing the right thing to include the dmaengine header
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Fixes: 08f738be88 (serial: at91: add tx dma support)
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
