The probe method of this driver calls clk_get(), but clk_put() is
missing from the remove callback.

Using the managed clk function is easier than fixing other parts.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Support command line parameters of the form:
earlycon=<name>,io|mmio|mmio32|mmio32be,<addr>,<options>

This commit seem to be needed even after commit:
serial: 8250: Add support for big-endian MMIO accesses
c627f2ce



Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

when the serial works as a bluetooth sink, due to audio realtime
requirement, the driver should have something similar with ALSA:
1. one big DMA buffer to easy the schedule jitter
2. split this big DMA buffer to multiple small periods, for each
period, we get a DMA interrupt, then push the data to userspace.
the small periods will easy the audio latency.

so ALSA generally uses a cyclic chained DMA.

but for sirfsoc, the dma hardware has the limitation: we have
only two loops in the cyclic mode, so we can only support two
small periods to switch. if we make the DMA buffer too big, we
get long latency, if we make the DMA buffer too little, we get
miss in scheduling for audio realtime.

so this patch moves to use a hrtimer to simulate the cyclic
DMA, then we can have a big buffer, and also have a timely
data push to users as the hrtimer can generate in small period
then actual HW interrupts.

with this patch, we also delete a lot of complex codes to handle
loop buffers, and RX timeout interrupt since the RX work can be
completely handled from hrtimer interrupt.

tests show using this way will make our bad audio streaming be-
come smooth.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

A corner case exists in the current driver. if an app opens the console
device, and before writing to console device, and there are huge kernel
ogs to print out, system will hang on
sirfsoc_uart_console_putchar:
while (rd_regl(port, ureg->sirfsoc_tx_fifo_status) &
	ufifo_st->ff_full(port->line))
	cpu_relax();
as in sirfsoc_uart_startup(), the driver assigns tx_fifo_op to 0 will stop
TX FIFO, this loop will be endless.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial8250_set_mctrl() is a void type function.  Returning something
does not look nice.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

RS-485 configuration is also done under the spinlock
so no blocking I/O allowed.

Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

.stop_rx/tx() are called in atomic context, we cannot use
blocking I/O. While at it correct the name of RX bit and
'*' placement in pointer declarations.

Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Convert md_proc into general async reconfiguration procedure.

Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Instead of spinning under port->lock let's just sleep
inside the kthread.  It should be equivalent as TX cannot
proceed when thread is blocked.

Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Convert workqueue usage to a real-time kworker.  The problem
with workqueues is that we cannot set real-time priorities on
our work and asynchronous reconfiguration can be blocked by
less important tasks.

We need kthread for the interrupt anyway and because we will
now be using single kthread for all TX-related operations we
can get rid of the port mutex.

Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

LSR_TEMT_BIT (LSR bit 6) provides us exactly the information
we need to determine if transmission is finished - FIFO level
and shift register empty.  We can save ourselves reading FIFO
level explicitly if we use this bit.

Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Without matching bus-specific strings driver will not be loaded
automatically.

Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Users of RS-485 can request via ioctl that RTS signals should
be activated selected number of milliseconds before the actual
data transmission or delay reception certain number of milli-
seconds after the transmission is finished.  In sc16is7xx,
however, RTS signalling is handled by the hardware and driver
has no way of providing this feature.

We still try to provide .delay_rts_before_send by delaying
transmission but without actual effect on the RTS line.

Note: this change will make the driver return -EINVAL when the
      feature is requested (.delay_rts_after_send is set).

Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Updated the documentation for spi interface.

Signed-off-by: Rama Kiran Kumar Indrakanti <indrakanti_ram@hotmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spi interface for sc16is7xx is added along with Kconfig flag
to enable spi or i2c, thus in a instance we can have either
spi or i2c or both, in sync to the hw.

Signed-off-by: Rama Kiran Kumar Indrakanti <indrakanti_ram@hotmail.com>
Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The header file, include/linux/serial_8250.h, contains references to
UART_LSR_BRK_ERROR_BITS and UART_MSR_ANY_DELTA that are defined in
<linux/serial_reg.h>.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 27a4c827

 ("fbcon: use the cursor blink interval provided by
vt") unconditionally removes the cursor blink timer. Unfortunately that
wreaks havoc under some circumstances. An easily reproducible way is to
use both the framebuffer console and a debug serial port as the console
output for kernel messages (e.g. "console=ttyS0 console=tty1" on the
kernel command-line. Upon boot this triggers a warning from within the
del_timer_sync() function because it is called from IRQ context:

	[    5.070096] ------------[ cut here ]------------
	[    5.070110] WARNING: CPU: 0 PID: 0 at ../kernel/time/timer.c:1098 del_timer_sync+0x4c/0x54()
	[    5.070115] Modules linked in:
	[    5.070120] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.1.0-rc4-next-20150519 #1
	[    5.070123] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
	[    5.070142] [] (unwind_backtrace) from [] (show_stack+0x10/0x14)
	[    5.070156] [] (show_stack) from [] (dump_stack+0x70/0xbc)
	[    5.070164] [] (dump_stack) from [] (warn_slowpath_common+0x74/0xb0)
	[    5.070169] [] (warn_slowpath_common) from [] (warn_slowpath_null+0x1c/0x24)
	[    5.070174] [] (warn_slowpath_null) from [] (del_timer_sync+0x4c/0x54)
	[    5.070183] [] (del_timer_sync) from [] (fbcon_del_cursor_timer+0x2c/0x40)
	[    5.070190] [] (fbcon_del_cursor_timer) from [] (fbcon_cursor+0x9c/0x180)
	[    5.070198] [] (fbcon_cursor) from [] (hide_cursor+0x30/0x98)
	[    5.070204] [] (hide_cursor) from [] (vt_console_print+0x2a8/0x340)
	[    5.070212] [] (vt_console_print) from [] (call_console_drivers.constprop.23+0xc8/0xec)
	[    5.070218] [] (call_console_drivers.constprop.23) from [] (console_unlock+0x498/0x4f0)
	[    5.070223] [] (console_unlock) from [] (vprintk_emit+0x1f0/0x508)
	[    5.070228] [] (vprintk_emit) from [] (vprintk_default+0x24/0x2c)
	[    5.070234] [] (vprintk_default) from [] (printk+0x70/0x88)

After which the system starts spewing all kinds of weird and seemingly
unrelated error messages.

This commit fixes this by restoring the condition under which the call
to fbcon_del_cursor_timer() happens.

Reported-by: Daniel Stone <daniel@fooishbar.org>
Reported-by: Kevin Hilman <khilman@kernel.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Scot Doyle <lkml14@scotdoyle.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Tested-by: Andrew Vagin <avagin@virtuozzo.com>
Tested-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add the necessary driver boilerplate to let the driver be used when
the respective ACPI table is discovered by the ACPI subsystem.

[Andre: change table name, add MODULE_DEVICE_TABLE entry and improve
	commit message]

Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The ARM Server Base System Architecture[1] document describes a
generic UART which is a subset of the PL011 UART.
It lacks DMA support, baud rate control and modem status line
control, among other things.
The idea is to move the UART initialization and setup into the
firmware (which does this job today already) and let the kernel just
use the UART for sending and receiving characters.

We use the recent refactoring to build a new struct uart_ops
variable which points to some new functions avoiding access to the
missing registers. We reuse as much existing PL011 code as possible.

In contrast to the PL011 the SBSA UART does not define any AMBA or
PrimeCell relations, so we go with a pretty generic probe function
which only uses platform device functions.
A DT binding is provided with this patch, ACPI support is added in a
separate one.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The SBSA UART has a fixed baud rate and flow control setting, which
cannot be changed or queried by software.
Add a vendor specific property to always return fixed values when
trying to read the console options.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The SBSA UART should not be enabled or disabled (it is always on),
and consequently the spec lacks the UART_CR register.
Add a vendor specific property to skip disabling or enabling of the
UART. This will be used later by the SBSA UART support.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

To avoid lines with more than 80 characters and to make the
pl011_int() function more readable, move the workaround out into a
separate function.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The PL011 register UART_MIS is actually a bitwise AND of the
UART_RIS and the UART_MISC register.
Since the SBSA UART does not include the _MIS register, use the
two separate registers to get the same behaviour. Since we are
inside the spinlock and we read the _IMSC register only once, there
should be no race issue.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently the pl011_probe() function is relying on some AMBA IDs
and a device tree node to initialize the driver and a port.
Both features are not necessarily required for the driver:
- we lack AMBA IDs in the ARM SBSA generic UART and
- we lack a DT node in ACPI systems.
So lets refactor the function to ease later reuse.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Split the pl011_set_termios() function into smaller chunks to allow
easier reuse later when adding SBSA support.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Split the pl011_shutdown() function into smaller chunks to allow
easier reuse later when adding SBSA support.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Split the pl011_startup() function into smaller chunks to allow
easier reuse later when adding SBSA support.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Although we care about not unregistering the driver if there are
still ports connected during the .remove callback, we do miss this
check in the pl011_probe function. So if the current port allocation
fails, but there are other ports already registered, we will kill
those.
So factor out the port removal into a separate function and use that
in the probe function, too.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If the mediatek serial port driver is built-in, but serial
console is disabled in Kconfig (e.g. when the serial driver
itself is a loadable module), we get this build error:

drivers/built-in.o: In function `early_mtk8250_setup':
undefined reference to `early_serial8250_setup'

To avoid that problem, this patch encloses the early_mtk8250_setup
function in #ifdef CONFIG_SERIAL_8250_CONSOLE, the same symbol
that guards the early_serial8250_setup function.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Eddie Huang <eddie.huang@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

A configuration that enables earlycon but not the core console
code causes a link error:

  drivers/built-in.o: In function `setup_earlycon':
  drivers/tty/serial/earlycon.c:70: undefined reference to `uart_parse_earlycon'

That error can be triggered by the newly added samsung earlycon support,
which is missing a 'select' statement.

As suggested by Peter Hurley, solves the problem by moving the
'select SERIAL_EARLYCON' statement to the samsung console driver
option, as it is done by all other console drivers.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: b94ba032

 ("serial: samsung: Add support for early console")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The platform_sysrq_reset_seq code was intended as a way for an embedded
platform to provide its own sysrq sequence at compile time. After over
two years, nobody has started using it in an upstream kernel, and
the platforms that were interested in it have moved on to devicetree,
which can be used to configure the sequence without requiring kernel
changes. The method is also incompatible with the way that most
architectures build support for multiple platforms into a single
kernel.

Now the code is producing warnings when built with gcc-5.1:

drivers/tty/sysrq.c: In function 'sysrq_init':
drivers/tty/sysrq.c:959:33: warning: array subscript is above array bounds [-Warray-bounds]
   key = platform_sysrq_reset_seq[i];

We could fix this, but it seems unlikely that it will ever be used,
so let's just remove the code instead. We still have the option to
pass the sequence either in DT, using the kernel command line,
or using the /sys/module/sysrq/parameters/reset_seq file.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 154b7a48

 ("Input: sysrq - allow specifying alternate reset sequence")
----
v2: moved sysrq_reset_downtime_ms variable to avoid introducing a compile
    warning when CONFIG_INPUT is disabled
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The function mctrl_gpio_init returns failure if the assignment to any
member of the gpio array results in an error pointer.  So there is no
need to check for such error values in the other functions.

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

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add DMA properties to all SCIF, SCIFA, SCIFB, and HSCIF device nodes.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add DMA properties to all SCIF, SCIFA, SCIFB, and HSCIF device nodes.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add DMA properties to all SCIF, SCIFA, SCIFB, and HSCIF device nodes.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The currently in-use port->startup and port->shutdown are "okay". The
startup part for instance does the tiny omap extra part and invokes
serial8250_do_startup() for the remaining pieces. The workflow in
serial8250_do_startup() is okay except for the part where UART_RX is
read without a check if there is something to read. I tried to
workaround it in commit 0aa525d1 ("tty: serial: 8250_core: read only
RX if there is something in the FIFO") but then reverted it later in
commit ca8bb4ae ("serial: 8250: Revert "tty: serial: 8250_core: read
only RX if there is something in the FIFO"").

This is the second attempt to get it to work on older OMAPs without
breaking other chips this time
Peter Hurley suggested to pull in the few needed lines from
serial8250_do_startup() and drop everything else that is not required
including making it simpler like using just request_irq() instead the
chain handler like it is doing now.
So lets try that.

Fixes: ca8bb4ae

 ("serial: 8250: Revert "tty: serial: 8250_core:
       read only RX if there is something in the FIFO"")
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If the call to dmaengine_slave_config() fails, then the DMA buffer will
not be freed/unmapped. Fix this by moving the code that stores the
address of the buffer in the tegra_uart_port structure to before the
call to dmaengine_slave_config().

Reported-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>