The UART_DUMMY_DR_RX status bit is equal to (1 << 16), so a u16 is too small
to hold that value. The result is that UART_DUMMY_DR_RX is never passed
to uart_insert_char(). This means that we're always accepting characters,
even when CREAD (in termios) is not set.
Signed-off-by: Timur Tabi <timur@codeaurora.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 534e14e229 as with
this patch the serial console is broken on lots of platforms.
Reported-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jun Nie <jun.nie@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 7b753f318d as with
this patch the serial console is broken on lots of platforms.
Reported-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jun Nie <jun.nie@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 2c096a9eed as with
this patch the serial console is broken on lots of platforms.
Reported-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jun Nie <jun.nie@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 09dcc7dfc0 as with
this patch the serial console is broken on lots of platforms.
Reported-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jun Nie <jun.nie@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 8cd90e50d1 as with
this patch the serial console is broken on lots of platforms.
Reported-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jun Nie <jun.nie@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Support ZTE uart with some registers differing offset.
Probe as platform device for not AMBA IP ID is
available on ZTE uart.
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Improve LCRH register access decision as ARM PL011 lcrh
register serve as both TX and RX, while other SOC may
implement TX and RX function with separated register.
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce register look up table as different SOC venders
may have different register offset for the some register.
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce register accessor to ease loop up table access
in later patch.
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Rename regs with enumeration to generalize register names.
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Value returned by devm_ioremap_resource() was checked for non-NULL but
devm_ioremap_resource() returns IOMEM_ERR_PTR, not NULL. In case of
error this could lead to dereference of ERR_PTR.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Cc: <stable@vger.kernel.org>
Fixes: 3873e2d7f6 ("drivers: PL011: refactor pl011_probe()")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the necessary driver boilerplate to let the driver be used when
the respective ACPI table is discovered by the ACPI subsystem.
[Andre: change table name, add MODULE_DEVICE_TABLE entry and improve
commit message]
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ARM Server Base System Architecture[1] document describes a
generic UART which is a subset of the PL011 UART.
It lacks DMA support, baud rate control and modem status line
control, among other things.
The idea is to move the UART initialization and setup into the
firmware (which does this job today already) and let the kernel just
use the UART for sending and receiving characters.
We use the recent refactoring to build a new struct uart_ops
variable which points to some new functions avoiding access to the
missing registers. We reuse as much existing PL011 code as possible.
In contrast to the PL011 the SBSA UART does not define any AMBA or
PrimeCell relations, so we go with a pretty generic probe function
which only uses platform device functions.
A DT binding is provided with this patch, ACPI support is added in a
separate one.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The SBSA UART has a fixed baud rate and flow control setting, which
cannot be changed or queried by software.
Add a vendor specific property to always return fixed values when
trying to read the console options.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The SBSA UART should not be enabled or disabled (it is always on),
and consequently the spec lacks the UART_CR register.
Add a vendor specific property to skip disabling or enabling of the
UART. This will be used later by the SBSA UART support.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To avoid lines with more than 80 characters and to make the
pl011_int() function more readable, move the workaround out into a
separate function.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The PL011 register UART_MIS is actually a bitwise AND of the
UART_RIS and the UART_MISC register.
Since the SBSA UART does not include the _MIS register, use the
two separate registers to get the same behaviour. Since we are
inside the spinlock and we read the _IMSC register only once, there
should be no race issue.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the pl011_probe() function is relying on some AMBA IDs
and a device tree node to initialize the driver and a port.
Both features are not necessarily required for the driver:
- we lack AMBA IDs in the ARM SBSA generic UART and
- we lack a DT node in ACPI systems.
So lets refactor the function to ease later reuse.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Split the pl011_set_termios() function into smaller chunks to allow
easier reuse later when adding SBSA support.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Split the pl011_shutdown() function into smaller chunks to allow
easier reuse later when adding SBSA support.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Split the pl011_startup() function into smaller chunks to allow
easier reuse later when adding SBSA support.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Although we care about not unregistering the driver if there are
still ports connected during the .remove callback, we do miss this
check in the pl011_probe function. So if the current port allocation
fails, but there are other ports already registered, we will kill
those.
So factor out the port removal into a separate function and use that
in the probe function, too.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit 02730d3c05
(Merge 4.1-rc4 into tty-next), git mismerged some lines,
reintroducing a reference to the removed field
uart_amba_port.tx_irq_seen. This causes a build failure.
This patch removes the mismerged lines, restoring the code to what
was in tty-next (which was the intention).
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit f2ee6dfa0e.
Jakub Kiciński observed that this patch can cause the pl011
driver to hang if if the only process with a pl011 port open is
killed by a signal, pl011_shutdown() can get called with an
arbitrary amount of data still in the FIFO.
Calling _shutdown() with the TX FIFO non-empty is questionable
behaviour and my itself be a bug.
Since the affected patch was speculative anyway, and brings limited
benefit, the simplest course is to remove the assumption that TXIS
will always be left asserted after the port is shut down.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 734745c serial/amba-pl011: Activate TX IRQ passively
adds some complexity and overhead in the form of a softirq
mechanism for transmitting in the absence of interrupts.
This patch simplifies the code flow to reduce the reliance on
subtle behaviour and avoid fragility under future maintenance.
To this end, the TX softirq mechanism is removed and instead
pl011_start_tx() will now simply stuff the FIFO until full
(guaranteeing future TX IRQs), or until there are no more chars
to write (in which case we don't care whether an IRQ happens).
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit f2ee6dfa0e.
Jakub Kiciński observed that this patch can cause the pl011
driver to hang if if the only process with a pl011 port open is
killed by a signal, pl011_shutdown() can get called with an
arbitrary amount of data still in the FIFO.
Calling _shutdown() with the TX FIFO non-empty is questionable
behaviour and my itself be a bug.
Since the affected patch was speculative anyway, and brings limited
benefit, the simplest course is to remove the assumption that TXIS
will always be left asserted after the port is shut down.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Unacceptable levels of debug info will happen when the DMA driver defined in
the DT/ACPI is a blacklisted module.
Another cause for log polution would be the defer probing of the DMA driver
taking too long - in which case the message that this commit removes would be
cluttering the logs due to the init daemons activity.
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix a race condition that happens when device_initcall(pl011_dma_initicall)
is executed before all the devices have been probed - this issue was observed on
a hisi_6220 SoC (HiKey board from Linaro).
The deferred driver probing framework relies on late_initcall to trigger
deferred probes so it is just possible that, even with a valid DMA driver ready
to be loaded, we fail to synchronize with it.
The proposed implementation delays probing the DMA until dma_startup.
As this is invoked on port startup and port resume - but DMA probing is only
required once - we avoid calling multiple times using a new field in
uart_amba_port to track this scenario.
This commit allows for subsequent attempts to associate an external DMA if the
DMA driver itself is not available (but present in the deferred probe pending
list).
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Getting the TX IRQ re-asserted from scratch can be inefficient in
some setups.
This patch avoids clearing the TX IRQ across pl011_shutdown()...
pl011_startup(), so that if the port is closed and reopened, the
IRQ will still work afterwards without having to bootstrap it again.
The TX IRQ continues to be masked in IMSC when the UART is not in
use.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current PL011 driver transmits a dummy character when the UART
is opened, to assert the TX IRQ for the first time
(see pl011_startup()). The UART is put in loopback mode temporarily,
so the receiver presumably shouldn't see anything.
However...
At least some platforms containing a PL011 send characters down the
wire even when loopback mode is enabled. This means that a
spurious NUL character may be seen at the receiver when the PL011 is
opened through the TTY layer.
The current code also temporarily sets the baud rate to maximum and
the character width to the minimum, to that the dummy TX completes
as quickly as possible. If this is seen by the receiver it will
result in a framing error and can knock the receiver out of sync --
turning subsequent output into garbage until synchronisation
is reestablished. (Particularly problematic during boot with systemd.)
To avoid spurious transmissions, this patch removes assumptions about
whether the TX IRQ will fire until at least one TX IRQ has been seen.
Instead, the UART will unmask the TX IRQ and then slow-start via
polling and timer-based soft IRQs initially. If the TTY layer writes
enough data to fill the FIFO to the interrupt threshold in one go,
the TX IRQ should assert, at which point the driver changes to
fully interrupt-driven TX.
In this way, the TX IRQ is activated as a side-effect instead of
being done deliberately.
This should also mean that the driver works on the SBSA Generic
UART[1] (a cut-down PL011) without invasive changes. The Generic
UART lacks some features needed for the dummy TX approach to work
(FIFO disabling and loopback).
[1] Server Base System Architecture (ARM-DEN-0029-v2.3)
http://infocenter.arm.com/
(click-thru required :/)
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add equivalent attributes to those provided in the platform data
for use when RX DMA is enabled.
Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the DMA engine doesn't support residue processing then the RX DMA
handling won't work terribly well if polling is enabled. So, disable
RX DMA if residue handling isn't available.
Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The DMA engines on some systems require that the dma_length is set
when using scatter gather lists.
Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The existing code assumed that PL011_DMA_BUFFER_SIZE == UART_XMIT_SIZE,
which may not always be the case. This allows for these two being
different sizes and not copying too much data.
Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allocating with __GFP_DMA avoids the need for bounce buffers
Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 479e9b94fd ("serial: Refactor uart_flush_buffer() from
uart_close") refactored the uart_flush_buffer() in uart_close() into
those drivers that define a flush_buffer() method. However, in the
amba-pl011 driver configured without CONFIG_DMA_ENGINE, flush_buffer()
is a NULL method, so the direct call fails to compile.
Check and call the flush_buffer() method through the ops table instead.
Reported-by: Fengguang Wu <fengguang.wu@intel.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>
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>
Universally adopt container_of() for all pointer conversion from
uart_port to uart_amba_port.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The label 'out' is only used to return the error code. We can return the
error code directly and remove 'out' label.
Signed-off-by: Tushar Behera <tushar.b@samsung.com>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If IGNBRK is set without either BRKINT or PARMRK set, some uart
drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the
line discipline, when it should send either nothing or the TTYBREAK flag
set. This happens because the read_status_mask masks out the BI
condition, which uart_insert_char() then interprets as a normal 0x00 byte.
SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General
Terminal Interface - Input Modes, states:
"If IGNBRK is set, a break condition detected on input shall be ignored;
that is, not put on the input queue and therefore not read by any
process."
Fix read_status_mask to include the BI bit if IGNBRK is set; the
lsr status retains the BI bit if a BREAK is recv'd, which is
subsequently ignored in uart_insert_char() when masked with the
ignore_status_mask.
Affected drivers:
8250 - all
serial_txx9
mfd
amba-pl010
amba-pl011
atmel_serial
bfin_uart
dz
ip22zilog
max310x
mxs-auart
netx-serial
pnx8xxx_uart
pxa
sb1250-duart
sccnxp
serial_ks8695
sirfsoc_uart
st-asc
vr41xx_siu
zs
sunzilog
fsl_lpuart
sunsab
ucc_uart
bcm63xx_uart
sunsu
efm32-uart
pmac_zilog
mpsc
msm_serial
m32r_sio
Unaffected drivers:
omap-serial
rp2
sa1100
imx
icom
Annotated for fixes:
altera_uart
mcf
Drivers without break detection:
21285
xilinx-uartps
altera_jtaguart
apbuart
arc-uart
clps711x
max3100
uartlite
msm_serial_hs
nwpserial
lantiq
vt8500_serial
Unknown:
samsung
mpc52xx_uart
bfin_sport_uart
cpm_uart/core
Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag'
Reported-by: Ivan <athlon_@mail.ru>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Enable DT based earlycon initialization for the pl011 uart.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Acked-by: Grant Likely <grant.likely@linaro.org>
Add earlycon support for the pl011 serial port. This allows enabling
the pl011 for console when early_params are processed. This is based
on the arm64 earlyprintk support and is intended to replace it.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A recent commit ef2889f7ff "serial: pl011:
Move uart_register_driver call to device probe" introduced a regression,
causing the pl011 driver to Oops if more than 1 port have been probed. Fix
the Oops by only calling uart_unregister_driver() once after the last port
has been removed.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The amba-pl011.c driver sets DMA burst size equal to FIFO trigger level.
If now exactly DMA burst size bytes are received, the DMAC will retrieve
them all and no Rx timeout interrupt will be generated. To fix that set
the burst size to half the FIFO trigger level.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uart_register_driver call binds the driver to a specific device
node through tty_register_driver call. This should typically happen
during device probe call.
In a multiplatform scenario, it is possible that multiple serial
drivers are part of the kernel. Currently the driver registration fails
if multiple serial drivers with same default major/minor numbers are
included in the kernel.
A typical case is observed with amba-pl011 and samsung-uart drivers.
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When falling back from DMA to interrupt mode the receive interrupt has to
be re-enabled to catch new incoming data.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In pl011_rx_chars() if pl011_dma_rx_trigger_dma() succeeds it will disable
the receive interrupt, no need to do this again.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During initialisation, a UART may already be in use for a console, so
take care to preserve things like baud rate and data format to avoid
corrupting console output.
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The code to cope with a split tx/rx LCR_H register is non-trivial
so put it into it's own function to avoid duplication.
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the pl011 is being used for a console, pl011_console_write forces
the control register (CR) to enable the UART for transmission and then
restores this to the original value afterwards. It does this while
holding the port lock.
Unfortunately, when the uart is started or shutdown - say in response to
userland using the serial device for a terminal - then this updates the
control register without any locking.
This means we can have
pl011_console_write Save CR
pl011_startup Initialise CR, e.g. enable receive
pl011_console_write Restore old CR with receive not enabled
this result is a serial port which doesn't respond to any input.
A similar race in reverse could happen when the device is shutdown.
We can fix these problems by taking the port lock when updating CR.
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 17438217a6 on request
of Linus Walleij:
Greg can you please drop or revert
commit 17438217a6
"serial: pl011: use DMA RX polling by default"
from the TTY tree until this has been sorted out?
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Making DMA RX polling optional when DMA is on was just
over-cautious: there is one single system in the kernel tree
using this facility, Ux500 and after some testing I turned
this on also for Ux500, which means it should simply be on
by default if DMA is enabled.
Cc: Jongsung Kim <neidhard.kim@lge.com>
Cc: Chanho Min <chanho.min@lge.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert to modern PM ops and use the SIMPLE_DEV_PM_OPS macro to set up
the PM callbacks.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This early amba_ports declaration was introduced by commit c16d51a32 (amba
pl011: workaround for uart registers lockup) for use in the pl011_lockup_wa()
routine. This routine was later removed by commit 4fd0690bb (serial: pl011:
implement workaround for CTS clear event issue).
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Driver core clears the driver data to NULL after device_release
or on probe failure, so just remove it from here.
Driver core change:
"device-core: Ensure drvdata = NULL when no driver is bound"
(sha1: 0998d06310)
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- A large slew of improvements of the Genric pin configuration
support, and deployment in four different platforms:
Rockchip, Super-H PFC, ABx500 and TZ1090. Support BIAS_BUS_HOLD,
get device tree parsing and debugfs support into shape.
- We also have device tree support with generic naming conventions
for the generic pin configuration.
- Delete the unused and confusing direct pinconf API. Now state
transitions is *the* way to control pins and multiplexing.
- New drivers for Rockchip, TZ1090, and TZ1090 PDC.
- Two pin control states related to power management are now
handled in the device core: "sleep" and "idle", removing a lot
of boilerplate code in drivers. We do not yet know if this is
the final word for pin PM, but it already make things a lot
easier to handle.
- Handle sparse GPIO ranges passing a list of disparate pins, and
utilize these in the new BayTrail (x86 Atom SoC) driver.
- Make the sunxi (AllWinner) driver handle external interrupts.
- Make it possible for pinctrl-single to handle the case where
several pins are managed by a single register, and augment it to
handle sleep modes.
- Cleanups and improvements for the abx500 drivers.
- Move Sirf pin control drivers to their own directory, support
save/restore of context and add support for the SiRFatlas6 SoC.
- PMU muxing for the Dove pinctrl driver.
- Finalization and support for VF610 in the i.MX6 pinctrl driver.
- Smoothen out various Exynos rough edges.
- Generic cleanups of various kinds.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.10 (GNU/Linux)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=EbAf
-----END PGP SIGNATURE-----
Merge tag 'pinctrl-for-v3.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull pin control changes from Linus Walleij:
- A large slew of improvements of the Genric pin configuration support,
and deployment in four different platforms: Rockchip, Super-H PFC,
ABx500 and TZ1090. Support BIAS_BUS_HOLD, get device tree parsing
and debugfs support into shape.
- We also have device tree support with generic naming conventions for
the generic pin configuration.
- Delete the unused and confusing direct pinconf API. Now state
transitions is *the* way to control pins and multiplexing.
- New drivers for Rockchip, TZ1090, and TZ1090 PDC.
- Two pin control states related to power management are now handled in
the device core: "sleep" and "idle", removing a lot of boilerplate
code in drivers. We do not yet know if this is the final word for
pin PM, but it already make things a lot easier to handle.
- Handle sparse GPIO ranges passing a list of disparate pins, and
utilize these in the new BayTrail (x86 Atom SoC) driver.
- Make the sunxi (AllWinner) driver handle external interrupts.
- Make it possible for pinctrl-single to handle the case where several
pins are managed by a single register, and augment it to handle sleep
modes.
- Cleanups and improvements for the abx500 drivers.
- Move Sirf pin control drivers to their own directory, support
save/restore of context and add support for the SiRFatlas6 SoC.
- PMU muxing for the Dove pinctrl driver.
- Finalization and support for VF610 in the i.MX6 pinctrl driver.
- Smoothen out various Exynos rough edges.
- Generic cleanups of various kinds.
* tag 'pinctrl-for-v3.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (82 commits)
pinctrl: vt8500: wmt: remove redundant dev_err call in wmt_pinctrl_probe()
pinctrl: remove bindings for pinconf options needing more thought
pinctrl: remove slew-rate parameter from tz1090
pinctrl: set unit for debounce time pinconfig to usec
pinctrl: more clarifications for generic pull configs
pinctrl: rip out the direct pinconf API
pinctrl-tz1090-pdc: add TZ1090 PDC pinctrl driver
pinctrl-tz1090: add TZ1090 pinctrl driver
pinctrl: samsung: Staticize drvdata_list
pinctrl: rockchip: Add missing irq_gc_unlock() call before return error
pinctrl: abx500: rework error path
pinctrl: abx500: suppress hardcoded value
pinctrl: abx500: factorize code
pinctrl: abx500: fix abx500_gpio_get()
pinctrl: abx500: fix abx500_pin_config_set()
pinctrl: abx500: Add device tree support
sh-pfc: Guard DT parsing with #ifdef CONFIG_OF
pinctrl: add Intel BayTrail GPIO/pinctrl support
pinctrl: fix pinconf_ops::pin_config_dbg_parse_modify kerneldoc
pinctrl: Staticize local symbols
...
Conflicts:
drivers/net/ethernet/ti/davinci_mdio.c
drivers/pinctrl/Makefile
This augments the PL011 UART driver to utilize the new pinctrl
core PM helpers to transition the driver to default and sleep
states, cutting away some boilerplate code.
Cc: Hebbar Gururaja <gururaja.hebbar@ti.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
It's completely feasible that platform data will be empty i.e. when
booting with Device Tree with no device AUXDATA. So we must protect
it's use in these use-cases, or risk a kernel Oops.
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch replaces the ugly bit-operations with the convenient
amba_rev macro from the get_fifosize_arm function. The type of
get_fifosize member function is also slightly changed to take
a pointer to the amba_device.
Signed-off-by: Jongsung Kim <neidhard.kim@lge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
These are cleanups and smaller changes that either depend on earlier
feature branches or came in late during the development cycle.
We normally try to get all cleanups early, so these are the exceptions:
- A follow-up on the clocksource reworks, hopefully the last time
we need to merge clocksource subsystem changes through arm-soc.
A first set of patches was part of the original 3.10 arm-soc cleanup
series because of interdependencies with timer drivers now moved out
of arch/arm.
- Migrating the SPEAr13xx platform away from using auxdata for DMA
channel descriptions towards using information in device tree,
based on the earlier SPEAr multiplatform series
- A few follow-ups on the Atmel SAMA5 support and other changes
for Atmel at91 based on the larger at91 reworks.
- Moving the armada irqchip implementation to drivers/irqchip
- Several OMAP cleanups following up on the larger series already
merged in 3.10.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)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=HWfp
-----END PGP SIGNATURE-----
Merge tag 'cleanup-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC late cleanups from Arnd Bergmann:
"These are cleanups and smaller changes that either depend on earlier
feature branches or came in late during the development cycle. We
normally try to get all cleanups early, so these are the exceptions:
- A follow-up on the clocksource reworks, hopefully the last time we
need to merge clocksource subsystem changes through arm-soc.
A first set of patches was part of the original 3.10 arm-soc
cleanup series because of interdependencies with timer drivers now
moved out of arch/arm.
- Migrating the SPEAr13xx platform away from using auxdata for DMA
channel descriptions towards using information in device tree,
based on the earlier SPEAr multiplatform series
- A few follow-ups on the Atmel SAMA5 support and other changes for
Atmel at91 based on the larger at91 reworks.
- Moving the armada irqchip implementation to drivers/irqchip
- Several OMAP cleanups following up on the larger series already
merged in 3.10."
* tag 'cleanup-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (50 commits)
ARM: OMAP4: change the device names in usb_bind_phy
ARM: OMAP2+: Fix mismerge for timer.c between ff931c82 and da4a686a
ARM: SPEAr: conditionalize SMP code
ARM: arch_timer: Silence debug preempt warnings
ARM: OMAP: remove unused variable
serial: amba-pl011: fix !CONFIG_DMA_ENGINE case
ata: arasan: remove the need for platform_data
ARM: at91/sama5d34ek.dts: remove not needed compatibility string
ARM: at91: dts: add MCI DMA support
ARM: at91: dts: add i2c dma support
ARM: at91: dts: set #dma-cells to the correct value
ARM: at91: suspend both memory controllers on at91sam9263
irqchip: armada-370-xp: slightly cleanup irq controller driver
irqchip: armada-370-xp: move IRQ handler to avoid forward declaration
irqchip: move IRQ driver for Armada 370/XP
ARM: mvebu: move L2 cache initialization in init_early()
devtree: add binding documentation for sp804
ARM: integrator-cp: convert use CLKSRC_OF for timer init
ARM: versatile: use OF init for sp804 timer
ARM: versatile: add versatile dtbs to dtbs target
...
I changed the prototype of the function earlier but only
in the section for CONFIG_DMA_ENGINE, not the alternative.
This makes the driver build again, e.g. for vexpress_defconfig.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The latest r1p5-revision of the ARM PL011 UART has 32-byte FIFOs,
while all earlier ones have 16-byte FIFOs. This patch suggests
a way to set the FIFO-size correctly & flexibly by using a member
function named get_fifosize, rather than using the fifosize member
variable. The function takes the UARTPeriphID, and returns the
correct FIFO size.
Signed-off-by: Jongsung Kim <neidhard.kim@lge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Following patch will fix build error if CONFIG_DMA_ENGINE is unset.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Chanho Min <chanho.min@lge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In DMA support, The received data is not pushed to tty until the DMA buffer
is filled. But some megabyte rate chips such as BT expect fast response and
data should be pushed immediately. In order to fix this issue, We suggest
the use of the timer for polling DMA buffer.
In our test, no data loss occurred at high-baudrate as compared with interrupt-
driven (We tested with 3Mbps).
We changes:
- We add timer for polling. If we set poll_timer to 10, every 10ms,
timer handler checks the residue in the dma buffer and transfer data
to the tty. Also, last_residue is updated for the next polling.
- poll_timeout is used to prevent the timer's system cost.
If poll_timeout is set to 3000 and no data is received in 3 seconds,
we inactivate poll timer and driver falls back to interrupt-driven.
When data is received again in FIFO and UART irq is occurred, we switch
back to DMA mode and start polling.
- We use consistent DMA mappings to avoid from the frequent cache operation
of the timer function for default.
- pl011_dma_rx_chars is modified. the pending size is recalculated because
data can be taken by polling.
- the polling time is adjusted if dma rx poll is enabled but no rate is
specified. Ideal polling interval to push 1 character at every interval
is the reciprocal of 'baud rate / 10 line bits per character / 1000 ms
per sec'. But It is very aggressive to system. Experimentally,
'10000000 / baud' is suitable to receive dozens of characters. the poll rate
can be specified statically by dma_rx_poll_rate of the platform data as well.
Changes compared to v1:
- Use of consistent DMA mappings.
- Added dma_rx_poll_rate in platform data to specify the polling interval.
- Added dma_rx_poll_timeout in platform data to specify the polling timeout.
Changes compared to v2:
- Use of consistent DMA mappings for default.
- Added dma_rx_poll_enable in platform data to adjust the polling time
according to the baud rate.
- remove unnecessary lock from the polling function.
Signed-off-by: Chanho Min <chanho.min@lge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With the new OF DMA binding, it is possible to completely avoid the
need for platform_data for configuring a DMA channel. In cases where the
platform has already been converted, calling dma_request_slave_channel
should get all the necessary information from the device tree.
This also adds a binding document specific to the pl011 controller,
and extends the generic primecell binding to mention "dmas" and other
common properties.
Like the patch that converts the dw_dma controller, this is completely
untested and is looking for someone to try it out.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.
IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.
Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
tty_insert_flip_string this time.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This switches a bunch of allocation and remapping to use the
devm_* garbage collected methods and cleans up the error
path and remove() paths consequently.
devm_ioremap() is only in <linux/io.h> so fix up the
erroneous <asm/*> include as well.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Domenico Andreoli <domenico.andreoli@linux.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We need to quiesce interrupts in the poll_get_char routine, otherwise,
if used with KGDB NMI debugger, we'll keep reentering the NMI.
Quiescing interrupts is pretty straightforward, except for TXIM
interrupt. The interrupt has "ready to transmit" meaning, so it's
almost always raised, and the only way to silence it is to mask it. But
that's OK, ops->start_tx will unmask it.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The callback is used to initialize the hardware, nothing else should be
done, i.e. we should not request interrupts (but we can and do unmask
some of them, as they might be useful for NMI entry).
As a side-effect, the patch also fixes a division by zero[1] when booting
with kgdboc options specified (e.g. kgdboc=ttyAMA0,115200n8). The issue
happens because serial core calls set_termios callback, but the driver
doesn't know clock frequency, and thus cannot calculate proper baud rate
values.
[1]
WARNING: at drivers/tty/serial/serial_core.c:400 uart_get_baud_rate+0xe8/0x14c()
Modules linked in:
[<c0018e50>] (unwind_backtrace+0x0/0xf0) from [<c0020ae8>] (warn_slowpath_common+0x4c/0x64)
[<c0020ae8>] (warn_slowpath_common+0x4c/0x64) from [<c0020b1c>] (warn_slowpath_null+0x1c/0x24)
[<c0020b1c>] (warn_slowpath_null+0x1c/0x24) from [<c0185ed8>] (uart_get_baud_rate+0xe8/0x14c)
[<c0185ed8>] (uart_get_baud_rate+0xe8/0x14c) from [<c0187078>] (pl011_set_termios+0x48/0x278)
[<c0187078>] (pl011_set_termios+0x48/0x278) from [<c01850b0>] (uart_set_options+0xe8/0x114)
[<c01850b0>] (uart_set_options+0xe8/0x114) from [<c0185de4>] (uart_poll_init+0xd4/0xe0)
[<c0185de4>] (uart_poll_init+0xd4/0xe0) from [<c016da8c>] (tty_find_polling_driver+0x100/0x17c)
[<c016da8c>] (tty_find_polling_driver+0x100/0x17c) from [<c0188538>] (configure_kgdboc+0xc8/0x1b8)
[<c0188538>] (configure_kgdboc+0xc8/0x1b8) from [<c00088a4>] (do_one_initcall+0x30/0x168)
[<c00088a4>] (do_one_initcall+0x30/0x168) from [<c033784c>] (do_basic_setup+0x94/0xc8)
[<c033784c>] (do_basic_setup+0x94/0xc8) from [<c03378e0>] (kernel_init+0x60/0xf4)
[<c03378e0>] (kernel_init+0x60/0xf4) from [<c00144a0>] (kernel_thread_exit+0x0/0x8)
---[ end trace 7d41c9186f342c40 ]---
Division by zero in kernel.
[<c0018e50>] (unwind_backtrace+0x0/0xf0) from [<c014546c>] (Ldiv0+0x8/0x10)
[<c014546c>] (Ldiv0+0x8/0x10) from [<c0187098>] (pl011_set_termios+0x68/0x278)
[<c0187098>] (pl011_set_termios+0x68/0x278) from [<c01850b0>] (uart_set_options+0xe8/0x114)
[<c01850b0>] (uart_set_options+0xe8/0x114) from [<c0185de4>] (uart_poll_init+0xd4/0xe0)
[<c0185de4>] (uart_poll_init+0xd4/0xe0) from [<c016da8c>] (tty_find_polling_driver+0x100/0x17c)
[<c016da8c>] (tty_find_polling_driver+0x100/0x17c) from [<c0188538>] (configure_kgdboc+0xc8/0x1b8)
[<c0188538>] (configure_kgdboc+0xc8/0x1b8) from [<c00088a4>] (do_one_initcall+0x30/0x168)
[<c00088a4>] (do_one_initcall+0x30/0x168) from [<c033784c>] (do_basic_setup+0x94/0xc8)
[<c033784c>] (do_basic_setup+0x94/0xc8) from [<c03378e0>] (kernel_init+0x60/0xf4)
[<c03378e0>] (kernel_init+0x60/0xf4) from [<c00144a0>] (kernel_thread_exit+0x0/0x8)
Division by zero in kernel.
[<c0018e50>] (unwind_backtrace+0x0/0xf0) from [<c014546c>] (Ldiv0+0x8/0x10)
[<c014546c>] (Ldiv0+0x8/0x10) from [<c0183a98>] (uart_update_timeout+0x4c/0x5c)
[<c0183a98>] (uart_update_timeout+0x4c/0x5c) from [<c01870f8>] (pl011_set_termios+0xc8/0x278)
[<c01870f8>] (pl011_set_termios+0xc8/0x278) from [<c01850b0>] (uart_set_options+0xe8/0x114)
[<c01850b0>] (uart_set_options+0xe8/0x114) from [<c0185de4>] (uart_poll_init+0xd4/0xe0)
[<c0185de4>] (uart_poll_init+0xd4/0xe0) from [<c016da8c>] (tty_find_polling_driver+0x100/0x17c)
[<c016da8c>] (tty_find_polling_driver+0x100/0x17c) from [<c0188538>] (configure_kgdboc+0xc8/0x1b8)
[<c0188538>] (configure_kgdboc+0xc8/0x1b8) from [<c00088a4>] (do_one_initcall+0x30/0x168)
[<c00088a4>] (do_one_initcall+0x30/0x168) from [<c033784c>] (do_basic_setup+0x94/0xc8)
[<c033784c>] (do_basic_setup+0x94/0xc8) from [<c03378e0>] (kernel_init+0x60/0xf4)
[<c03378e0>] (kernel_init+0x60/0xf4) from [<c00144a0>] (kernel_thread_exit+0x0/0x8)
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This works around a few glitches in the ST version of the PL011
serial driver when using very high baud rates, as we do in the
Ux500: 3, 3.25, 4 and 4.05 Mbps.
Problem Observed/rootcause:
When using high baud-rates, and the baudrate*8 is getting close to
the provided clock frequency (so a division factor close to 1), when
using bursts of characters (so they are abutted), then it seems as if
there is not enough time to detect the beginning of the start-bit which
is a timing reference for the entire character, and thus the sampling
moment of character bits is moving towards the end of each bit, instead
of the middle.
Fix:
Increase slightly the RX baud rate of the UART above the theoretical
baudrate by 5%. This will definitely give more margin time to the
UART_RX to correctly sample the data at the middle of the bit period.
Also fix the ages old copy-paste error in the very stressed comment,
it's referencing the registers used in the PL010 driver rather than
the PL011 ones.
Signed-off-by: Guillaume Jaunet <guillaume.jaunet@stericsson.com>
Signed-off-by: Christophe Arnal <christophe.arnal@stericsson.com>
Signed-off-by: Matthias Locher <matthias.locher@stericsson.com>
Signed-off-by: Rajanikanth HV <rajanikanth.hv@stericsson.com>
Cc: stable <stable@vger.kernel.org>
Cc: Bibek Basu <bibek.basu@stericsson.com>
Cc: Par-Gunnar Hjalmdahl <par-gunnar.hjalmdahl@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The bug flag .interrupt_may_hang is not used since commit
4fd0690bb0
"serial: pl011: implement workaround for CTS clear event issue"
so delete it.
Cc: Rajanikanth H.V <rajanikanth.hv@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the order of UART nodes is changed in the device tree, then tty dev
devices are attached to different serial ports causing the console to
be directed to a different physical serial port. The "serial" aliases
in the device tree should prevent this.
This patch ensures that the UART driver creates tty devices that
honour these aliases if a device tree is present.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Clk_prepare_enable and clk_disable_unprepare combine clk_prepare and
clk_enable, and clk_disable and clk_unprepare. The9 make the code more
concise, and ensure that clk_unprepare is called when clk_enable fails.
A simplified version of the semantic patch that introduces calls to these
functions is as follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
expression e;
@@
- clk_prepare(e);
- clk_enable(e);
+ clk_prepare_enable(e);
@@
expression e;
@@
- clk_disable(e);
- clk_unprepare(e);
+ clk_disable_unprepare(e);
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This handles the merge issue in:
arch/um/drivers/line.c
arch/um/drivers/line.h
And resolves the duplicate patches that were in both trees do to the
tty-next branch not getting merged into 3.6-rc1.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is to pick up the serial port and tty changes in Linus's tree to allow
everyone to sync up.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The PL011 driver has a number of symbols referring to "pl01x"
(probably once shared with the pl010 driver) and some even named
"pl010" (probably a pure copy-paste artifact). Lets name all
local static functions with the prefix pl011_* for clarity.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We had a boot regression in Ux500 in the merge window because
two orthogonal pin control schemes for the PL011 were merged
at the same time:
- One using the .init() and .exit() hooks into the platform
for Ux500 putting the pins into default vs sleep state
respectively as the port was started/stopped.
commit a09806607f
"ARM: ux500: switch to using pinctrl for uart0"
- One hogging the default setting at PL011 probe()
commit 258e055111
"serial: amba-pl011: adopt pinctrl support"
To get a solution that works for both let's scrap the stuff
in the platform callbacks, instead have the driver itself
select default and sleep states when the port is
started/stopped. Hopefully this works for all clients.
Platform callbacks are bad for device tree migration anyway,
so this rids us of another problem in Ux500.
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Reported-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here's the big TTY/serial driver pull request for the 3.5-rc1 merge window.
Nothing major in here, just lots of incremental changes from Alan and
Jiri reworking some tty core things to behave better and to get a more
solid grasp on some of the nasty tty locking issues.
There are a few tty and serial driver updates in here as well.
All of this has been in the linux-next releases for a while with no problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.18 (GNU/Linux)
iEYEABECAAYFAk+7rBoACgkQMUfUDdst+ykXsgCfeDKx6ZgLidYy3H40Y2Pt3XEO
TicAn1fcdGwOmMR/mowa+kTA68D/J6i2
=S7tG
-----END PGP SIGNATURE-----
Merge tag 'tty-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull TTY updates from Greg Kroah-Hartman:
"Here's the big TTY/serial driver pull request for the 3.5-rc1 merge
window.
Nothing major in here, just lots of incremental changes from Alan and
Jiri reworking some tty core things to behave better and to get a more
solid grasp on some of the nasty tty locking issues.
There are a few tty and serial driver updates in here as well.
All of this has been in the linux-next releases for a while with no
problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
* tag 'tty-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (115 commits)
serial: bfin_uart: Make MMR access compatible with 32 bits bf609 style controller.
serial: bfin_uart: RTS and CTS MMRs can be either 16-bit width or 32-bit width.
serial: bfin_uart: narrow the reboot condition in DMA tx interrupt
serial: bfin_uart: Adapt bf5xx serial driver to bf60x serial4 controller.
Revert "serial_core: Update buffer overrun statistics."
tty: hvc_xen: NULL dereference on allocation failure
tty: Fix LED error return
tty: Allow uart_register/unregister/register
tty: move global ldisc idle waitqueue to the individual ldisc
serial8250-em: Add DT support
serial8250-em: clk_get() IS_ERR() error handling fix
serial_core: Update buffer overrun statistics.
tty: drop the pty lock during hangup
cris: fix missing tty arg in wait_event_interruptible_tty call
tty/amiserial: Add missing argument for tty_unlock()
tty_lock: Localise the lock
pty: Lock the devpts bits privately
tty_lock: undo the old tty_lock use on the ctty
serial8250-em: Emma Mobile UART driver V2
Add missing call to uart_update_timeout()
...
Problem Observed:
- interrupt status is set by rising or falling edge on CTS line
- interrupt status is cleared on a .0. to .1. transition of the
interrupt-clear register bit 1.
- interrupt-clear register is reset by hardware once the interrupt
status is .0..
Remark: It seems not possible to read this register back by the
CPU though, but internally this register exists.
- when simultaneous set and reset event on the interrupt status
happens, then the set-event has priority and the status remains
.1.. As a result the interrupt-clear register is not reset to
.0., and no new .0. to .1. transition can be detected on it when
writing a .1. to it.
This implies race condition, the clear must be performed at least
one UARTCLK the riding edge of CTS RIS interrupt.
Fix:
Instead of resetting UART as done in commit
c16d51a32b
"amba pl011: workaround for uart registers lockup" do the
following:
write .0. and then .1. to the interrupt-clear register to make
sure that this transition is detected. According to the datasheet
writing a .0. does not have any effect, but actually it allows to
reset the internal interrupt-clear register.
Take into account:
The .0. needs to last at least for one clk_uart clock period
(~ 38 MHz, 26.08ns)
This way we can do away with the tasklet and keep only a tiny
fix triggered by the variant flag introduced in this patch.
Signed-off-by: Guillaume Jaunet <guillaume.jaunet@stericsson.com>
Signed-off-by: Christophe Arnal <christophe.arnal@stericsson.com>
Signed-off-by: Matthias Locher <Matthias.Locher@stericsson.com>
Signed-off-by: Rajanikanth H.V <rajanikanth.hv@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 360f748b204275229f8398cb2f9f53955db1503b
"serial: PL011: clear pending interrupts"
attempts to clear interrupts by writing to a
yet-unassigned memory address. This fixes the issue.
The breaking patch is marked for stable so should be
carried along with the other patch.
Cc: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: stable <stable@vger.kernel.org>
Cc: Nicolas Pitre <nico@fluxnic.net>
Reported-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull slave-dmaengine update from Vinod Koul:
"This includes the cookie cleanup by Russell, the addition of context
parameter for dmaengine APIs, more arm dmaengine driver cleanup by
moving code to dmaengine, this time for imx by Javier and pl330 by
Boojin along with the usual driver fixes."
Fix up some fairly trivial conflicts with various other cleanups.
* 'next' of git://git.infradead.org/users/vkoul/slave-dma: (67 commits)
dmaengine: imx: fix the build failure on x86_64
dmaengine: i.MX: Fix merge of cookie branch.
dmaengine: i.MX: Add support for interleaved transfers.
dmaengine: imx-dma: use 'dev_dbg' and 'dev_warn' for messages.
dmaengine: imx-dma: remove 'imx_dmav1_baseaddr' and 'dma_clk'.
dmaengine: imx-dma: remove unused arg of imxdma_sg_next.
dmaengine: imx-dma: remove internal structure.
dmaengine: imx-dma: remove 'resbytes' field of 'internal' structure.
dmaengine: imx-dma: remove 'in_use' field of 'internal' structure.
dmaengine: imx-dma: remove sg member from internal structure.
dmaengine: imx-dma: remove 'imxdma_setup_sg_hw' function.
dmaengine: imx-dma: remove 'imxdma_config_channel_hw' function.
dmaengine: imx-dma: remove 'imxdma_setup_mem2mem_hw' function.
dmaengine: imx-dma: remove dma_mode member of internal structure.
dmaengine: imx-dma: remove data member from internal structure.
dmaengine: imx-dma: merge old dma-v1.c with imx-dma.c
dmaengine: at_hdmac: add slave config operation
dmaengine: add context parameter to prep_slave_sg and prep_dma_cyclic
dmaengine/dma_slave: introduce inline wrappers
dma: imx-sdma: Treat firmware messages as warnings instead of erros
...
Add inline wrappers for device_prep_slave_sg() and device_prep_dma_cyclic()
interfaces to hide new parameter from current users of affected interfaces.
Convert current users to use new wrappers instead of direct calls.
Suggested by Russell King [https://lkml.org/lkml/2012/2/3/269].
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Chanho Min reported that when the boot loader transfers
control to the kernel, there may be pending interrupts
causing the UART to lock up in an eternal loop trying to
pick tokens from the FIFO (since the RX interrupt flag
indicates there are tokens) while in practice there are
no tokens - in fact there is only a pending IRQ flag.
This patch address the issue with a combination of two
patches suggested by Russell King that clears and mask
all interrupts at probe() and clears any pending error
and RX interrupts at port startup time.
We suspect the spurious interrupts are a side-effect of
switching the UART from FIFO to non-FIFO mode.
Cc: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Reported-by: Chanho Min <chanho0207@gmail.com>
Suggested-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Jong-Sung Kim <neidhard.kim@lge.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In DMA-operated uart, I found that rx data can be taken by the UART
interrupts during the DMA irq handler. pl011_int is occurred just
before it goes inside spin_lock_irq. When it returns to the callback,
DMA buffer already has been flushed. Then, pl011_dma_rx_chars gets
invalid data. So I add check for the residue as the patch bellow.
Signed-off-by: Chanho Min <chanho.min@lge.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
.device_fc is added in struct dma_slave_config recently. All user drivers, which
want DMA to be the flow controller must pass this field as false. As earlier
driver don't look to use this feature, mark it false for now.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Protect against pl011_console_write() and the interrupt for
the console UART running concurrently on different CPUs.
Otherwise the console_write could spin for a long time
waiting for the UART to become not busy, while the other
CPU continuously services UART interrupts and keeps the
UART busy.
The checks for sysrq and oops_in_progress are taken
from 8250.c.
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Reviewed-by: Bibek Basu <bibek.basu@stericsson.com>
Reviewed-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In present driver, shutdown clears RTS and DTR in CR register. But the
documentation "Documentation/serial/driver" suggests not to disable
RTS and DTR in shutdown(). Also RTS and DTR is preserved between shutdown
and startup calls, i.e. these are restored in startup if they were enabled
while doing shutdown. So that if RTS and DTR are set using pl011_set_mctrl
then it should continue even after shutdown->startup sequence.
For throttling/unthrottling user should call pl011_set_mctrl.
Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Timur Tabi
Greg Kroah-Hartman
Jun Nie
Krzysztof Kozlowski
Graeme Gregory
Andre Przywara
Dave Martin
Jorge Ramirez-Ortiz
Andrew Jackson
Peter Hurley
Daniel Thompson
Tushar Behera
Rob Herring
Guennadi Liakhovetski
Tushar Behera
Jon Medhurst
Linus Walleij
Ulf Hansson
Baruch Siach
Michal Simek
Fabio Estevam
Jingoo Han
Linus Torvalds
Lee Jones
Jongsung Kim
Arnd Bergmann
Chanho Min
Jiri Slaby
Anton Vorontsov
Matthew Leach
Julia Lawall
Russell King
Alessandro Rubini
Shawn Guo
Rajanikanth H.V
Alexandre Bounine
Chanho Min
Viresh Kumar
Rabin Vincent
Shreshtha Kumar Sahu
Dave Martin
Vinod Koul