The runtime PM of sh-sci devices is enabled when sci_probe() returns,
so the pm_runtime_put_sync() executed by driver_probe_device()
attempts to suspend the device.  Then, in some situations, a
diagnostic message is printed to the console by one of the runtime
suspend routines handling the sh-sci device, which causes synchronous
runtime resume to be started from the device's own runtime suspend
callback.  This causes rpm_resume() to be run eventually, which sees
the RPM_SUSPENDING status set by rpm_suspend() and waits for it to
change.  However, the device's runtime PM status cannot change at
that point, because the routine that has set it waits for the
rpm_suspend() to return.  A deadlock occurs as a result.

To avoid that make sci_init_single() increment the device's
runtime PM usage counter, so that it cannot be suspended by
driver_probe_device().  That counter has to be decremented
eventually, so make sci_startup() do that before starting to
actually use the device and make sci_shutdown() increment it
again before returning to balance the incrementation carried out by
sci_startup().
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Tested-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This adds initial support for requesting the various GPIO functions
necessary for certain ports. This just plugs in dumb request/free logic,
but serves as a building block for migrating off of the ->init_pins mess
to a wholly gpiolib backed solution (primarily parts with external
RTS/CTS pins, but will also allow us to clean up RXD pin testing).
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

When toggling the MCE support we don't want to concern ourselves with the
FIFO state, so ensure that the clearing bits are masked out when updating
the MCE state.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The bulk of the ports do not support any sort of modem control, so
blindly twiddling the MCE bit doesn't accomplish much. We now require
ports to manually specify which line supports modem control signals.

While at it, tidy up the RTS/CTSIO handling in SCSPTR parts so it's a bit
more obvious what's going on (and without clobbering other configurations
in the process).
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This plugs in loopback control for SCFCR-enabled ports and plugs it in
via the TIOCM_LOOP control, as others do.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

At the moment things like CTS/RTS are reported for all ports, while the
vast majority of them do not implement support at all (and others
implement support entirely in hardware). Fix up the ->get_mctrl()
reporting to simply assert DSR/CAR as other drivers without control
lines do.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Technically there's nothing we can do for either of these, so update the
comments to reflect this, rather than infering that there's additional
work to be done.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Presently the icount stats are only adjusted for the rx/tx case, this
makes sure that they're updated appropriately for the non-tx/rx cases,
too (specifically overruns, breaks, as well as frame and parity errors).
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Presently there are a few places that make assumptions about the
existence of SCFCR, which doesn't hold true for several port types. While
generally harmless, this does lead to bogus reads/writes in both the
termios/runtime PM cases that are better off simply never being made in
the first place.

While we're at it, also get rid of a straggling PORT_SCI check that
infers all non-SCI ports contain SCFCR. This doesn't presently have any
impact, but as we're now able to test for the existence of registers
without defering to the port type we future proof for additional port
types.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This fixes up support for SH-2(A) SCIFs by introducing a new regtype. As
expected, it's close to the SH-4A SCIF with fifodata, but still different
enough to warrant its own type.

Fixes up a number of FIFO overflows and similar for both SH7203/SH7264.
Signed-off-by: NPhil Edworthy <phil.edworthy@renesas.com>
Tested-by: NFederico Fuga <fuga@studiofuga.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

fixup usage of dma direction by introducing dma_transfer_direction,
this patch moves spi, serial drivers to use new enum
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: NMika Westerberg <mika.westerberg@iki.fi>

Since commit [e58aa3d2: genirq: Run irq handlers with interrupts disabled],
We run all interrupt handlers with interrupts disabled
and we even check and yell when an interrupt handler
returns with interrupts enabled (see commit [b738a50a:
genirq: Warn when handler enables interrupts]).

So now this flag is a NOOP and can be removed.
Signed-off-by: NYong Zhang <yong.zhang0@gmail.com>
Acked-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

On some sh-mobile systems there are more than one DMA controllers, that
can be used for serial ports. Specifying a DMA device in sh-sci platform
data unnecessarily restricts the driver to only use one DMA controller.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
[Fixed the trivial conflict in include/linux/serial_sci.h]
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

sh-sci.c sets hardware up and then let the HW do all flow controls.
There is no software code, nor needs to get/set real CTS signal.

But, when turning CRTSCTS on through termios, uart_set_termios() in
serial_core.c checks CTS, and stops TX if it is inactive at the moment.

Because sci_get_mctrl() returns a fixed value DTR|RTS|DSR but CTS,
the sequence
  open -> set CRTSCTS -> write
hit the case and stop working, no more outputs.

This patch makes sci_get_mctrl() report CTS in addition.
Signed-off-by: NTakashi YOSHII <takashi.yoshii.zj@renesas.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Since sci_port_enable() and sci_port_disable() may be run with
interrupts off and they execute pm_runtime_get_sync() and
pm_runtime_put_sync(), respectively, the SCI device's
power.irq_safe flag has to be set to indicate that it is safe
to execute runtime PM callbacks for this device with interrupts off.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NMagnus Damm <damm@opensource.se>

Commit d006199e72a9 ("serial: sh-sci: Regtype probing doesn't need to be
fatal.") made sci_init_single() return when sci_probe_regmap() succeeds,
although it should return when sci_probe_regmap() fails.  This causes
systems using the serial sh-sci driver to crash during boot.

Fix the problem by using the right return condition.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add Runtime PM context save/restore support to
the SCIF driver. Tested on the AP4EVB console.
Signed-off-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Include dma-mapping.h to fix build of the sh-sci driver on
SH-Mobile ARM (sh73a0) when CONFIG_SERIAL_SH_SCI_DMA=y:

drivers/tty/serial/sh-sci.c: In function 'sci_rx_dma_release':
drivers/tty/serial/sh-sci.c:1182:3: error: implicit declaration of function 'dma_free_coherent'
drivers/tty/serial/sh-sci.c: In function 'work_fn_tx':
drivers/tty/serial/sh-sci.c:1333:2: error: implicit declaration of function 'dma_sync_sg_for_device'
drivers/tty/serial/sh-sci.c: In function 'sci_request_dma':
drivers/tty/serial/sh-sci.c:1498:3: error: implicit declaration of function 'dma_map_sg'
drivers/tty/serial/sh-sci.c:1527:3: error: implicit declaration of function 'dma_alloc_coherent'
drivers/tty/serial/sh-sci.c:1527:10: warning: assignment makes pointer from integer without a cast
make[3]: *** [drivers/tty/serial/sh-sci.o] Error 1
make[2]: *** [drivers/tty/serial] Error 2
make[1]: *** [drivers/tty] Error 2
make: *** [drivers] Error 2
Signed-off-by: NMagnus Damm <damm@opensource.se>
Tested-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Presently the default regtype probing inadvertently bails out due to an
inverted error check. This fixes it up, and gets platforms without
explicit regtype specifications working again.
Reported-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Presently these were all using the same static string with no regard to
dev_name() and the like. This implements a bit of rework to name the IRQ
dynamically, as it should have been doing all along anyways.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Ultimately we want everything to be going through the clock framework and
runtime pm, so kill off the per-port callbacks that enabled ports to
bypass the common infrastructure.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This was using a BUG_ON(), but it's not strictly necessary, so relax the
constraints a bit.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

For all ports with a valid SCLSR register we can use the generic FIFO
overrun detection logic. Test the validity of the SCLSR register rather
than depending explicitly on port type, which can be ambiguous for the
SCIFA/B types.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This consolidates all of the TX/RX fill/room nonsense in to a single set
of fairly heavyweight definitions. The implementation goes in descending
order of complexity, testing the register map for capabilities until we
run out of options and do it the legacy SCI way. Masks are derived
directly from the per-port FIFO size, meaning that platforms with FIFO
sizes not matching the standard port types will still need to manually
fix them up.

This also fixes up a number of issues such as tx_empty being completely
bogus for SCI and IrDA ports, some ports using masks smaller or greater
than their FIFO size, and so forth.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This takes a bit of a sledgehammer to the horribly CPU subtype
ifdef-ridden header and abstracts all of the different register layouts
in to distinct types which in turn can be overriden on a per-port basis,
or permitted to default to the map matching the port type at probe time.

In the process this ultimately fixes up inumerable bugs with mismatches
on various CPU types (particularly the legacy ones that were obviously
broken years ago and no one noticed) and provides a more tightly coupled
and consolidated platform for extending and implementing generic
features.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Non-SCI parts do not have the special port reg necessary for cases where
the RX and SCI pins are muxed and need to be manually polled, so these
like always fall back on the normal FIFO processing paths. SH7760 is in a
class in and of itself with regards to mapping its SIM card interface via
the SCI port class despite not having any of the RXD lines wired up and
so implicitly behaving more like a SCIF in this regard. Out of the other
CPUs, some support the port check via the same block while others do it
through an external SuperI/O, so it's not even possible to perform the
check relative to the ioremapped cookie offset, so the separate read
semantics are preserved here, too.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This consolidates all of the broken out overrun handling and ensures that
we have sensible defaults per-port type, in addition to making sure that
overruns are flagged appropriately in the error mask for parts that
haven't explicitly disabled support for it.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

h8300 has never been updated upstream to support the conversion to the
driver model (which happened mid-2.5), and it doesn't seem likely that it
ever will. Kill off the remaining bitrotted support to reduce the
maintenance burden going forward.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This patch adds wakeup support to the sh-sci driver. The serial
core deals with all details but defaults to wakeup disabled. So
to make use of this feature enable wakeup in sysfs:

echo enabled > /sys/class/tty/ttySC0/power/wakeup
Signed-off-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Add support for Runtime PM in the sh-sci driver.
Signed-off-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

remove invalid location line in each file header after location
moved from driver/char to driver/tty
Signed-off-by: NJovi Zhang <bookjovi@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

The driver is initialized in a state with an unknown value by
serial_console_setup. And initialization fails.

This is caused by the initialization by sci_console_init.
This function does not seem to be necessary for the present sh-sci driver.
Signed-off-by: NNobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Commit 906b17dc introduced a condition
where the kernel will crash unless a earlyprintk parameter is specified.

Without this parameter, sci_console_init is called during early console
setup without any port being initialized, and the kernel crashes a
little bit later when uart_set_options attemps to invoke set_termios on a
port with an ops member equal to NULL.

This patch just checks in sci_console_init that the port is properly
initialized, and aborts the early console setup if it is not.
Signed-off-by: NAlexandre Courbot <gnurou@gmail.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

S3 sleep invokes the shutdown callback of the sh-sci driver, which
suspends the clocks until they are reactivated by a call to startup.
However, before the latter is invoked, sci_set_termios may be called on
the port by uart_resume_port. In such cases it will endlessly wait for
the TEND bit to raise, which will never happen since the clocks are
disabled.

This patch ensures that clocks are enabled when ports registers are
manipulated within sci_set_termios.
Signed-off-by: NAlexandre Courbot <gnurou@gmail.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The serial drivers are really just tty drivers, so move them to
drivers/tty/ to make things a bit neater overall.

This is part of the tty/serial driver movement proceedure as proposed by
Arnd Bergmann and approved by everyone involved a number of months ago.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl>
Cc: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This fixes up the port_rx_irq_mask() REIE flag definition as well as a
debug printk blowing up on the SCSCR_INIT having gone away.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

SCIFB ports have a slightly different register layout and a different FIFO
size from SCIFA ports, in DMA mode they have to be treated just like SCIFA.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Fix an Oops, triggering, if the DMA buffer allocation for the Rx channel in
sh-sci.c fails.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>