There are three natural ways in which devices may be wired to the system:
little endian (device receives correctly ordered bits of a word written
by little-endian CPU to its register, but big-endian CPU needs to swap
bytes of a word before writing it), big endian (same, but with big-endian
CPU in more favourable position) and native endian (CPU of either
endianness may do word-sized I/O without need for byteswapping).

Adding an option for native endianness allows using single kernel command
line for boards with native-endian serial ports on bi-endian
architectures. This goes in parallel with 'native-endian' DTS attribute.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

These drivers doesn't claim the serial device to be wakeup source. Even
if it is, it needs to use enable_irq_wake or other related PM wakeup
APIs to enable it.

This patch removes yet another misuse of IRQF_NO_SUSPEND.

Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: kernel@stlinux.com
Cc: linux-serial@vger.kernel.org
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since the FD interrupt handler can discern spurious IRQs and it is
shared with timer interrupt, use IRQF_COND_SUSPEND instead of
IRQF_NO_SUSPEND.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The function can return negative values.

The problem has been detected using proposed semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2038576Signed-off-by: NAndrzej Hajda <a.hajda@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: NLuis de Bethencourt <luisbg@osg.samsung.com>
Acked-by: NTimur Tabi <timur@tabi.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: NLuis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: NLuis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: NLuis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some SoCs, including Ralink/Mediatek and Alchemy Au1xxx, have a
16550-like UART with a non-standard register layout.  These are
supported by a simple mapping table in 8250_port.c  Rather than
list every SoC type using this access mode in the ifdefs there,
allow selecting the SERIAL_8250_RT288X Kconfig option with any
system and default it to y for the known cases needing it.  The
help text is reworded accordingly.

This change simplifies adding support for other SoCs also using
the same UART.

The name of the option is a little misleading, but not knowing
the true origin of this UART, it is as good a choice as any.
Signed-off-by: NMans Rullgard <mans@mansr.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This allows to reduce the per-driver boiler plate considerably.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg 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: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit also fixes compiler warnings and errors seen when building
on x86_64.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The RX bytecount was only updated in the PIO path and thus
the device erroneously reported a value of 0 if DMA is in
use.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The commit enabling DMA support even if no flow control is present
was reverted on the grounds that it uncovered a number of bugs in
the code that lead to hanging tty devices and/or missing characters.

After tracking down the issues it is clear that those were generic
bugs and had nothing to do with flow control being present or not,
only that allowing DMA without hardware flow control increased
the exposure of that code a lot.

Now that those bugs are fixed, it should be safe to re-enable DMA
support.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The reference manual states that idle condition detect should not be used
with DMA transfers, as the ROM SDMA scripts don't check those conditions.

The RAM SDMA scripts worked around this, but the change broke compatibility
with the ROM scripts.

The previous commits fixed the DMA burst sizes, so that the aging timer is
now working as described in the reference manual. With this fixed we can
remove the hack of using the idle condition detect to stop the DMA transfer
if there are no new characters incoming.

This should work with both the ROM and RAM SDMA scripts.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Triggering the DMA engine for every byte is horribly inefficient.
Also it doesn't allow to use the aging timer for the RX FIFO as this
requires the DMA engine to leave one byte remaining in the FIFO when
doing a normal burst transfer.

Adjust watermark levels so that the DMA engine can do at least 8 byte
burst transfers. This is a conservative value, as the both TX and RX
FIFOs are able to contain 32 bytes.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Simplify the DMA restart logic to always queue up the next transfer
immediately if there is at least one more byte available in the FIFO,
so that the transfer will finish in a limited time.

This way the driver stops to rely on zero length transfers to signal
transfers ends. Those will go away when the idle detect DMA requests
are disabled.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The DMA transfer is only started once we are sure it will finish
in a limited time, i.e. only after we received a RRDY interrupt.

In order to allow the watermark level to be raised the aging
timer and the corresponding interrupt need to be set up as an
additional trigger, so that the transfer is also started if the
incoming amount of bytes never reach the watermark.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This function currently doesn't use its parameter.

Change prototype to pass in watermark levels, so we can reuse this
function in the DMA setup paths. Also relocate to be near the calling
functions.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

serial8250_register_8250_port adds it to all ports it
registers. No need to set it separately.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Using the same style of declaring variables as used in the
other functions of the driver. Passing uart_port to the
function instead of uart_8250_port, as it is the one mostly
needed.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove the extra return.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Adding comment where the purpose of the function is
explained.

The dma parameters are not used, so removing them, and also
moving the assignment of the function to the same place
where the other dw8250_data structures members are being set
in dw8250_probe.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If the DW_apb_uart is configured with UART_16550_COMPATIBLE
configuration parameter set, then the Busy Functionality is
not available. These UARTs will never generate the Busy
detect indication interrupt, and therefore don't need
handling for it.

This creates a small optimization for the DW_apb_uarts
configured without the busy functionality, but more
importantly, it removes the small but real risk of hitting
potential issues caused by busy functionality handling when
no busy functionality exist.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Merging the DT and ACPI specific probe functions into
dw8250_quirks. Those functions did not have that much code
any more and some of the quirks need to be shared. This
will also allow platforms without DT or ACPI to use the
driver.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds a flag "skip_autocfg" that the platforms that do
not have the ADDITIONAL_FEATURES implemented can use to skip
the port setup. It's then enough to call dw8250_setup_port
just from dw8250_probe based on that flag.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Instead of assigning the dma member in dw8250_probe_of and
dw8250_probe_acpi separately, assigning it in dw8250_probe.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This makes the properties available for all types of
platforms instead of just the ones using DT.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For convenience, adding separate pointer for the "port"
member of struct uart_8250_port that is being filled in the
probe function.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This allows earlycon to be used without needing to specify the I/O
address on the kernel command line, if linux,stdout-path is specified
in the chosen node.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Earlycon allows to have an early debugging console that doesn't need
to be statically configured in the kernel config, like earlyprintk,
but is set up through the stdout-path DT property.

This allows to have the early debugging always built into the
kernel and enabled on demand without clashing between different boards
or architectures.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add support for debug communications channel based
hvc console for arm64 cpus.
Signed-off-by: NAbhimanyu Kapur <abhimany@codeaurora.org>
Signed-off-by: NTimur Tabi <timur@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

hvc_instantiate() and hvc_alloc() return errors if they fail, so don't
ignore them.
Signed-off-by: NTimur Tabi <timur@codeaurora.org>
Signed-off-by: NGreg 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: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If the 8250 driver is compiled as a module then
CONFIG_SERIAL_8250_MODULE is defined and not CONFIG_SERIAL_8250.

This results in all those code sections that require CONFIG_SERIAL_8250
to be defined are not included.

This patch fixes the situation and allows 8250 and of-serial to
be compiled as a module with the same functionality as when
compiled into the kernel.
Signed-off-by: NMartin Sperl <kernel@martin.sperl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use of_property_read_u32 instead of of_get_property with return value
checks and endianness conversion. Also remove the !CONFIG_OF
implementation of altera_uart_get_of_uartclk as of_property_read_u32
will return a non-zero value for !CONFIG_OF.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add these variants of the UART as compatible strings
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>

blah
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Enable the TX/RX FIFOs present on UARTs in Ingenic SoCs.
FIFO sizes vary per device so match these based on
the OF compatible string

Enabling the FIFOs permits much faster transfer with
lower CPU overhead.

Tested on Ingenic JZ4780 on the MIPS Ci20 Creator board
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Ingenic UART is similar to a standard 16550, but hardware flow control
requires setting a couple of additional, non-standard bits in the MCR.

The non-standard "modem control enable" and "hardware flow control
mode" bits are set when writing to the MCR register, based
on whether the modem control interrupt is active.

Additionally the non-16550 compliant parts of the uart need to be
masked from higher layers.

Tested on Ingenic JZ4780 on MIPS Creator Ci20 board
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>