[Blackfin] serial driver: rework break flood anomaly handling to be more robust/realistic about what we can actually work around
Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

[Blackfin] serial driver: fix bug - cache the bits of the LSR on systems where the LSR is read-to-clear

Cache the bits of the LSR on systems where the LSR is read-to-clear
so that we can safely read the LSR in random places.  this fixes
older parts where break/framing/parity/overflow was not being detected
at all in PIO mode, and this fixes newer parts where
break/framing/parity/overflow was being reported all the time
without being cleared.
Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

[Blackfin] serial driver: Fix bug serial driver in DMA mode spams history to console on shell restart

http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=2920
Fix by increasing buffer tail immediately before starting tx dma.
Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Kernel crash for the serial driver in DMA mode:
http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=3679Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Start next TX DMA in tx dma handler instead of rx timer handler.
Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Output as many bytes as possible in PIO tx handler.
This reduce the number of tx interrupts and shorten the delay to handle
rx interrupt. So, rx overrun disappears.
Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

We should only return IRQ_HANDLED when we actually found something to
handle. This is important since the USART interrupt handler may be
shared with the timer interrupt on some chips.
Pointed-out-by: Nmichael <trimarchi@gandalf.sssup.it>
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

asm/hardware.h doesn't exist any more, and the definitions sh-sci.h
depended on are provided through asm/cpu/addrspace.h these days.
Kill off the bogus include.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This patch adds sh7366 cpu supports. Just the most basic things like interrupt
controller, clocks and serial port are included at this point.
Signed-off-by: NMagnus Damm <damm@igel.co.jp>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

There is an outdated comment in serial_core.c also fixed.
Signed-off-by: NDenis Cheng <crquan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When possible, pass the tty name to request_irq() so that the user can easily
distinguish the different serial ports in /proc/interrupts.
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Tested-by: NMarc Pignat <marc.pignat@hevs.ch>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As pointed out by David Brownell, we really ought to be using container_of
when converting from "struct uart_port *" to "struct atmel_uart_port *".
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Tested-by: NMarc Pignat <marc.pignat@hevs.ch>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Introduced by atmel_serial-split-the-interrupt-handler.patch.

Thanks to michael <trimarchi@gandalf.sssup.it> for spotting it.
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch is based on the DMA-patch by Chip Coldwell for the AT91/AT32 serial
USARTS, with some tweaks to make it apply neatly on top of the other patches
in this series.

The RX and TX code has been moved to a tasklet and reworked a bit.  Instead of
depending on the ENDRX and TIMEOUT bits in CSR, we simply grab as much data as
we can from the DMA buffers.  I think this closes a race where the ENDRX bit
is set after we read CSR but before we read RPR, although I haven't confirmed
this.

Similarly, the two TX handlers (ENDTX and TXBUFE) have been combined into one.
 Since the current code only uses a single TX buffer, there's no point in
handling those interrupts separately.

This also fixes a DMA sync bug in the original patch.

[linux@bohmer.net: rebased onto irq-splitup patch]
[hskinnemoen@atmel.com: moved to tasklet, fixed dma bug, misc cleanups]
[hskinnemoen@atmel.com: atmel_serial dma: Misc fixes and cleanups]
Signed-off-by: NRemy Bohmer <linux@bohmer.net>
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Tested-by: NMarc Pignat <marc.pignat@hevs.ch>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Split up the interrupt handler of the serial port into a interrupt top-half
and a tasklet.

The goal is to get the interrupt top-half as short as possible to minimize
latencies on interrupts.  But the old code also does some calls in the
interrupt handler that are not allowed on preempt-RT in IRQF_NODELAY context.
This handler is executed in this context because of the interrupt sharing with
the timer interrupt.  The timer interrupt on Preempt-RT runs in IRQF_NODELAY
context.

The tasklet takes care of handling control status changes, pushing incoming
characters to the tty layer, handling break and other errors.  It also handles
pushing TX data into the data register.

Reading the complete receive queue is still done in the top-half because we
never want to miss any incoming character.

[hskinnemoen@atmel.com: misc cleanups and simplifications]
Signed-off-by: NRemy Bohmer <linux@bohmer.net>
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Tested-by: NMarc Pignat <marc.pignat@hevs.ch>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When an error happens in probe(), the clocks should be disabled, but
only if the port isn't already used as a console.

In remove(), the port struct shouldn't be freed because it's defined
statically.
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Tested-by: NMarc Pignat <marc.pignat@hevs.ch>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If BRGR is zero, the baud rate generator isn't running, so the boot loader
can't have initialized the port.
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: NAndrew Victor <linux@maxim.org.za>
Tested-by: NMarc Pignat <marc.pignat@hevs.ch>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace two instances of barrier() with cpu_relax() since that's the right
thing to do when busy-waiting.  This does not actually change anything since
cpu_relax() is defined as barrier() on both ARM and AVR32.
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: NAndrew Victor <linux@maxim.org.za>
Tested-by: NMarc Pignat <marc.pignat@hevs.ch>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Clean up the atmel_serial driver to conform the coding rules.  It contains no
functional change.
Signed-off-by: NRemy Bohmer <linux@bohmer.net>
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: NAndrew Victor <linux@maxim.org.za>
Tested-by: NMarc Pignat <marc.pignat@hevs.ch>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a set of changes to implement proper resource management in the
driver, including iomem space reservation and operating on physical
addresses ioremap()ped appropriately using accessory functions rather than
unportable direct assignments.

Some adjustments to code are made to reflect the architecture of the
interface, which is a centrally controlled multiport (or, as referred to
from DEC documentation, a serial line multiplexer, going up to 8 lines
originally) rather than a bundle of separate ports.

Types are changed, where applicable, to specify the width of hardware
registers explicitly.  The interrupt handler is now managed in the
->startup() and ->shutdown() calls for consistency with other drivers and
also in preparation to handle the handover from the initial firmware-based
console gracefully.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace all casts from "struct uart_port *" to "struct dz_port *" with a
construct based on container_of().  This makes the conversion work
irrespective of where the former struct is located within the latter.

By popular request I have implemented it as an inline function rather than
a macro this time.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A set of changes to the way termios settings are propagated to the serial
port hardware.  The DZ11 only supports a selection of fixed baud settings,
so some requests may not be fulfilled.  Keep the old setting in such a case
and failing that resort to 9600bps.  Also add a missing update of the
transmit timeout.  And remove the explicit encoding of the line selected
from writes to the Line Parameters Register as it has been preencoded by
the ->set_termios() call already.  Finally, remove a duplicate macro for
the Receiver Enable bit.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Handle the read and ignore status masks correctly.  Handle the BREAK condition
as expected: a framing error with a null character is a BREAK, any other
framing error is a framing error indeed.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ->start_tx(), ->stop_tx() and ->stop_rx() backends are called with the
port's lock already taken.  Remove locking from within them and wrap around
calls as necessary.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rename the serial console structure so that `modpost' does not complain about
a reference to an "init" section -- "_console" is magic.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Reformat the Kconfig entries and update descriptions for accuracy.  Select the
driver by default for configurations of interest.  For the curious: 32BIT
means only 32-bit DECstations support the device, not that the driver is not
64-bit clean; I have not checked that either though.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Sort the header inclusions, add a few that are needed but pulled indirectly
only and remove ones that are not really used.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Well, panic() is a little bit undue if request_irq() fails; there is probably
no need to justify it any further.  Handle the case gracefully, by
unregistering the driver.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Polled transmission is tricky enough with the DZ11 design.  While "loop" is
set to a high value, conceptually you are not allowed to transmit without
checking whether the device offers the right transmission line (yes, it is the
device that selects the line -- the driver has no control over it other than
disabling the transmitter offered if it is the wrong one), so the loop has to
be run at least once.

Well, the '1977 or PDP11 view of how serial lines should be handled...  Except
that the serial interface used to be quite an impressive board back then
rather than chip.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove unused module function prototypes that would not even build if enabled.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>