All call sites for serial8250_handle_port() acquired the port spinlock
and released it afterwards. This is a needless duplication of code.
Move the spinlocking inside serial8250_handle_port().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reading the MSR register on 8250-compatible UARTs results in any
modem status interrupts being cleared. To avoid missing any
status changes, arrange for get_mctrl() to read the current
status via check_modem_status(), which will process any pending
state changes for us.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch marks a few serial data structures const, moving them to
.rodata where they won't false-share cachelines with things that get
written to.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
xscale-type UARTs have an extra bit (UUE) in the IER register that has
to be written as 1 to enable the UART. At the end of autoconfig() in
drivers/serial/8250.c, the IER register is unconditionally written as
zero, which turns off the UART, and makes any subsequent printch() hang
the box.
Since other 8250-type UARTs don't have this enable bit and are thus
always 'enabled' in this sense, it can't hurt to enable xscale-type
serial ports all the time as well. The attached patch changes the
autoconfig() exit path to see if the port has an UUE enable bit, and if
yes, to write UUE=1 instead of just putting a zero into IER, using the
same test as is used at the beginning of serial8250_console_write().
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This allows us to eliminate the casts in the drivers, and eventually
remove the use of the device_driver function pointer methods for
platform device drivers.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Large console spews from IRQ or local_irq_disable() sections can cause the NMI
watchdog to go off.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The offsets of the registers are in a different place, and
some parts cannot handle a full set of modem control signals.
Signed-off-by: Pantelis Antoniou <pantelis@embeddedalley.ocm>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Convert everyone who uses platform_bus_type to include
linux/platform_device.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
In PM v1, all devices were called at SUSPEND_DISABLE level. Then
all devices were called at SUSPEND_SAVE_STATE level, and finally
SUSPEND_POWER_DOWN level. However, with PM v2, to maintain
compatibility for platform devices, I arranged for the PM v2
suspend/resume callbacks to call the old PM v1 suspend/resume
callbacks three times with each level in order so that existing
drivers continued to work.
Since this is obsolete infrastructure which is no longer necessary,
we can remove it. Here's an (untested) patch to do exactly that.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Rather than hard-coding the platform device IDs, enumerate them.
We don't particularly care about the actual ID we get, just as
long as they're unique.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Sascha Hauer
This patch adds support for setting and getting RTS / CTS via
set_mtctrl / get_mctrl functions.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The start_tx and stop_tx methods were passed a flag to indicate
whether the start/stop was from the tty start/stop callbacks, and
some drivers used this flag to decide whether to ask the UART to
immediately stop transmission (where the UART supports such a
feature.)
There are other cases when we wish this to occur - when CTS is
lowered, or if we change from soft to hard flow control and CTS
is inactive. In these cases, this flag was false, and we would
allow the transmitter to drain before stopping.
There is really only one case where we want to let the transmitter
drain before disabling, and that's when we run out of characters
to send.
Hence, re-jig the start_tx and stop_tx methods to eliminate this
flag, and introduce new functions for the special "disable and
allow transmitter to drain" case.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If CONFIG_SERIAL_8250_NR_UARTS is smaller than the array size in
asm/serial.h, we trampled on memory which wasn't ours. Take our
big boots away by limiting the number of ports initialised to the
smaller of ...NR_UARTS and the array size.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Remove legacy ISA serial ports for Accent, Boca, Fourport, Hub6 and MCA
from the architecture specific serial.h include.
The only ports which remain in asm-*/serial.h are the platform specific
entries. These should really be converted by platform maintainers to
use a platform device, such as can be found in
arch/arm/mach-footbridge/isa.c
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Disable the transmitter whenever we want to prevent characters
being transmitted by flow control. However, if we run out of
characters to send and want to only disable the TX interrupt,
allow that scenario.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch changes the way serial ports are locked when getting modem
status. This change is necessary because we will need to atomically
read the modem status and take action depending on the CTS status.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add separate files for the different 8250 ISA-based serial boards.
Looking across all the various architectures, it seems reasonable that
we can key the availability of the configuration options for these
beasts to the bus-related symbols (iow, CONFIG_ISA). We also standardise
the base baud/uart clock rate for these boards - I'm sure that isn't
architecture specific, but is solely dependent on the crystal fitted
on the board (which should be the same no matter what type of machine
its fitted into.)
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Use the existing macros instead.
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The Mobility 16550A serial ports don't behave the same as standard
16550A ports, and need a helping hand to get them going once the
transmitter has drained and been disabled.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
For some 8250 port types, we used to check the type of the port, and
then determine whether the chip revision means the device is buggy.
Instead, introduce a bit array, and set the appropriate bit(s) when
we discover a buggy device.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
with high-speed mode enabled, we switch it to high-speed mode so that
baud_base becomes 921600. However, we also need to multiply the baud
divisor by 8 at the same time, in case it's already in use as a console.
Signed-off-by: David Woodhouse
Acked-by: Tom Rini
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add uart_insert_char(), which handles inserting characters into the
flip buffer. This helper function handles the correct semantics
for handling overrun in addition to inserting normal characters.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Another large rollup of various patches from Adrian which make things static
where they were needlessly exported.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix the formatting of some comments in 8250.c, and add a note that the
register_serial / unregister_serial shouldn't be used in new code.
We do this here in preference to adding to linux/serial.h, since that is used
by a number of non-8250 drivers which pretend to be 8250. It is not known
whether it would be appropriate to do so.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Russell King
Arjan van de Ven
Lennert Buytenhek
Andrew Morton
Pantelis Antoniou
Russell King
Sascha Hauer
David Woodhouse
Adrian Bunk
Russell King
Linus Torvalds