Prepare for 8250 split; separate RSA probe and resource management
from base port operations. Override base port operations for the
config_port(), request_port() and release_port() methods to
implement the optional RSA probe and resource management only in
the universal/legacy 8250 driver.

Introduce 'probe' flags for 8250 ports, which allows drivers higher
up the driver stack to enable optional probes.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The probe for Remote Supervisor Adapter is limited to port i/o
addresses which match one of the probe_rsa[] module parameter
addresses. Limit RSA resource acquire to matching i/o ports.

The result is a saner probe policy: only perform optional probes
when specified rather than by default.

NB: It is possible for userspace to set the port type == PORT_RSA
with ioctl(TIOCSSERIAL) and then autoconfig with ioctl(TIOCSERCONFIG),
which if it fails, may leave the port type set to PORT_RSA. Since
this may have previously resulted in a working RSA port, this behavior
is preserved.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Support for Remote Supervisor Adapter is conditional on
CONFIG_SERIAL_8250_RSA; only attempt RSA resource acquire if
defined.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Prepare for 8250 split; move default dma tx/rx handler initialization
into serial8250_set_defaults(), which allows default dma ops to
remain unexported from the base port operations module after the split.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Prepare for 8250 split; move fixed type initialization into
serial8250_set_defaults(). This enables uart_config[] array to remain
file scope in base port operations after the split.

NB: the call to serial8250_init_fixed_type_port() from
serial8250_register_ports() was added by commit b5d228cc
("serial: copy UART properties of UPF_FIXED_TYPE ports provisioned
using early_serial_setup") specifically to support ports initialized
by early_serial_setup(). Since serial8250_set_defaults() is called
from early_serial_setup(), fixed type initialization is now already
handled there before serial8250_register_ports() is called.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Prepare for 8250 split; introduce serial8250_set_defaults() to set default
port methods prior to driver override.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Prepare for 8250 split; introduce serial8250_init_port() to initialize
port fields uncoupled from port structure storage.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Prepare for 8250 split; decouple irq setup/teardown and handler from
core port operations.

Introduce setup_irq() and release_irq() 8250 driver methods; the 8250
core will use these methods to install and remove irq handling for
the given 8250 port.

Refactor irq chain linking/unlinking from 8250 core into
univ8250_setup_irq()/univ8250_release_irq() for the universal 8250 driver.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Prepare for 8250 core split; separate shared console interface from the
console definition of the universal driver.

Introduce 8250 shared console interface; serial8250_console_write() and
serial8250_console_setup() which decouples the console operation from
the port structure storage.

Rename existing serial8250_console* identifiers to univ8250_console*.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

setup_earlycon() will now match and register the desired earlycon
from the param string (as if 'earlycon=...' had been set on the
command line). Use setup_earlycon() from existing arch call sites
which start an earlycon directly.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Earlycon matching can only be triggered if 'earlycon=...' has been
specified on the kernel command line. To workaround this limitation
requires tight coupling between arches and specific serial drivers
in order to start an earlycon. Devicetree avoids this limitation
with a link table that contains the required data to match earlycons.

Mirror this approach for earlycon match by name. Re-purpose
EARLYCON_DECLARE to generate a table entry which associates name with
setup() function. Re-purpose setup_earlycon() to scan this table for
an earlycon match, which is registered if found.

Declare one "earlycon" early_param, which calls setup_earlycon().

This design allows setup_earlycon() to be called directly with a
param string (as if 'earlycon=...' had been set on the command line).
Re-registration (either directly or by early_param) is prevented.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Separate earlycon matching from registration; add register_earlycon
which initializes and registers the matched earlycon.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Earlycon param strings of the form
   earlycon=<name>
are rejected from parse_options() with an error (which, in turn,
results in a NULL argument for the setup() method options parameter).

Only pass non-empty string to parse_options(); this will enable
handling actual parse errors differently than expected and allow
formats.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Because setup_earlycon() continues to attempt console registration
if an error occurred parsing the option string, the actual value of
the error code from parse_options() is ignored.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If parsing failed to decode a valid uart addr, return -ENODEV instead
of success. Although setup_earlycon() will detect the failure anyway
(because the write() method has not been set), that behavior is not
obvious and should not be relied on.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The <baud><parity><bit> option string is not supplied if the earlycon
is started via devicetree and OF_EARLYCON_DECLARE(). The option string
is also not required if started via kernel command line parameters of
the form:
  earlycon=uart,mmio,<addr>
  console=uart,mmio,<addr>

If earlycon_device->baud is 0, then an option string was not supplied.
In this case, assume the uart has already been initialized by the
bootloader or firmware.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Initializing the ->uartclk field is not related to option parsing;
relocate from parse_options() to setup_earlycon() (which mirrors the
behavior of of_setup_earlycon()).
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

early_device was only required for serial8250_find_port_for_earlycon(),
which was replaced by extensible console matching.

Fixup early_serial8250_write() to get the earlycon_device * from
console->data (which is initialized by {of_}setup_earlycon()).
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

'/**' is required to start a kernel-doc comment block.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add match() method to struct console which allows the console to
perform console command line matching instead of (or in addition to)
default console matching (ie., by fixed name and index).

The match() method returns 0 to indicate a successful match; normal
console matching occurs if no match() method is defined or the
match() method returns non-zero. The match() method is expected to set
the console index if required.

Re-implement earlycon-to-console-handoff with direct matching of
"console=uart|uart8250,..." to the 8250 ttyS console.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Prepare for 8250 split; initialize the port flags based on the
"skip_txen_test" module param to use the existing flag test.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Prepare for 8250_core.c file split; move shared inline function
to local header file.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since uart->port.type has just reset to PORT_UNKNOWN, capabilities
are reset to uart_config[PORT_UNKNOWN].flags, which is 0.

Removes unnecessary dependency on uart_config[].
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

set_io_from_upio() already initializes ->handle_irq to
serial8250_default_handle_irq.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Prepare for 8250 split; calculate the ttyS index directly from
the port minor which avoids the global serial8250_reg reference
from base port operations.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

UART drivers that share ttyS namespace cannot trivially compute the
ttyS index from the port->line value since the minor_start may be
offset from minor 64. Further, to do so requires a pointer to the
uart driver since there is no back pointer from uart_port to
uart_driver.

Rather than have UART drivers computing the minor value by themselves,
encapsulate within the serial core at port registration time.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add irq disable and enable in bfin_serial_rx_dma_timeout in case of
system hang.

This reverts part of commit 9642dbe7 ("serial: bfin-uart: avoid
dead lock in rx irq handler in smp kernel").
Signed-off-by: NHao Liang <hliang1025@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We are dealing with CTS, not DSR here (we dealt with DSR a few lines
above), so set appropriate bits.
Reported-by: NKevin Cernekee <cernekee@chromium.org>
Signed-off-by: NDmitry Torokhov <dtor@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Trying to write console output from within the serial console driver
while the port->lock is held causes recursive deadlock:

  CPU 0
spin_lock_irqsave(&port->lock)
printk()
  console_unlock()
    call_console_drivers()
      serial8250_console_write()
        spin_lock_irqsave(&port->lock)
** DEADLOCK **

The 8250_dw i/o accessors try to write a console error message if the
LCR workaround was unsuccessful. When the port->lock is already held
(eg., when called from serial8250_set_termios()), this deadlocks.

Make the error message a FIXME until a general solution is devised.

Cc: Tim Kryger <tim.kryger@gmail.com>
Reported-by: NZhang Zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg 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: NJorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes the following sparse warnings:

drivers/tty/serial/8250/8250_core.c:3231:32: warning: incorrect type in assignment (different base types)
drivers/tty/serial/8250/8250_core.c:3231:32:    expected restricted upf_t [usertype] flags
drivers/tty/serial/8250/8250_core.c:3231:32:    got unsigned int const [unsigned] flags
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 17b8f2a3 ("serial: imx: add support for half duplex rs485")
introduced the following build warning:

drivers/tty/serial/imx.c: In function 'imx_set_termios':
drivers/tty/serial/imx.c:1301:7: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]

Add the suggested braces to avoid the build warning.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix the following build warnings:

drivers/tty/serial/serial_mctrl_gpio.c: In function 'mctrl_gpio_init':
drivers/tty/serial/serial_mctrl_gpio.c:110:4: warning: return makes pointer from integer without a cast
    return PTR_ERR(gpios->gpio[i]);
    ^
/home/build/work/batch/drivers/tty/serial/serial_mctrl_gpio.c:90:6: warning: unused variable 'err' [-Wunused-variable]
  int err;
      ^

Return ERR_CAST and remove the unused 'err' variable to fix them.

Fixes: 1d267ea6 ("serial: mctrl-gpio: simplify init routine")
Reported-by: NOlof's autobuilder <build@lixom.net>
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 343fda95 ("serial: mxs-auart: properly handle mctrl_gpio
failing") introduced the following build error:

  CC      drivers/tty/serial/mxs-auart.o
drivers/tty/serial/mxs-auart.c: In function 'mxs_auart_probe':
drivers/tty/serial/mxs-auart.c:1282:3: error: unknown type name 'got'

Fix it by providing a proper return code.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It is not recommened to use platform_get_resource(pdev, IORESOURCE_IRQ)
for requesting IRQ's resources any more, as they can be not ready yet in
case of DT-booting.

platform_get_irq() instead is a recommended way for getting IRQ even if
it was not retrieved earlier.

It also makes code simpler because we're getting "int" value right away
and no conversion from resource to int is required.
Signed-off-by: NAlexey Brodkin <abrodkin@synopsys.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Prepare to support console-defined matching; refactor the command
line parameter string processing from parse_options() into a
new core function, uart_parse_earlycon(), which decodes command line
parameters of the form:
   earlycon=<name>,io|mmio|mmio32,<addr>,<options>
   console=<name>,io|mmio|mmio32,<addr>,<options>
   earlycon=<name>,0x<addr>,<options>
   console=<name>,0x<addr>,<options>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg 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: NLeilei Zhao <leilei.zhao@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg 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: NLeilei Zhao <leilei.zhao@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg 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: NLeilei Zhao <leilei.zhao@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg 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: NLeilei Zhao <leilei.zhao@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>