The geni serial driver had a rule that we'd only use 1 byte per FIFO
word for the TX FIFO if we were being used for the serial console.
This is ugly and a bit of a pain.  It's not too hard to fix, so fix
it.
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NEvan Green <evgreen@chromium.org>
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200626125844.2.Iabd56347670b9e4e916422773aba5b27943d19ee@changeidSigned-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

The geni serial driver had the rather sketchy hack in it where it
would adjust the number of bytes per RX FIFO word from 4 down to 1 if
it detected that CONFIG_CONSOLE_POLL was enabled (for kgdb) and this
was a console port (defined by the kernel directing output to this
port via the "console=" command line argument).

The problem with that sketchy hack is that it's possible to run kgdb
over a serial port even if it isn't used for console.

Let's avoid the hack by simply handling the 4-bytes-per-FIFO word case
for kdb.  We'll have to have a (very small) cache but that should be
fine.

A nice side effect of this patch is that an agetty (or similar)
running on this port is less likely to drop characters.  We'll
have roughly 4 times the RX FIFO depth than we used to now.

NOTE: the character cache here isn't shared between the polling API
and the non-polling API.  That means that, technically, the polling
API could eat a few extra bytes.  This doesn't seem to pose a huge
problem in reality because we'll only get several characters per FIFO
word if those characters are all received at nearly the same time and
we don't really expect non-kgdb characters to be sent to the same port
as kgdb at the exact same time we're exiting kgdb.

ALSO NOTE: we still have the sketchy hack for setting the number of
bytes per TX FIFO word in place, but that one is less bad.  kgdb
doesn't have any problem with this because it always just sends 1 byte
at a time and waits for it to finish.  The TX FIFO hack is only really
needed for console output.  In any case, a future patch will remove
that hack, too.
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NEvan Green <evgreen@chromium.org>
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200626125844.1.I8546ecb6c5beb054f70c5302d1a7293484212cd1@changeidSigned-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

geni serial needs to express a perforamnce state requirement on CX
powerdomain depending on the frequency of the clock rates.
Use OPP table from DT to register with OPP framework and use
dev_pm_opp_set_rate() to set the clk/perf state.
Signed-off-by: NRajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Akash Asthana <akashast@codeaurora.org>
Cc: linux-serial@vger.kernel.org
Link: https://lore.kernel.org/r/1592222564-13556-2-git-send-email-rnayak@codeaurora.orgSigned-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Get the interconnect paths for Uart based Serial Engine device
and vote according to the baud rate requirement of the driver.
Signed-off-by: NAkash Asthana <akashast@codeaurora.org>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/1592908737-7068-5-git-send-email-akashast@codeaurora.orgSigned-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

QUP core clock is shared among all the SE drivers present on particular
QUP wrapper, the system will reset(unclocked access) if earlycon used after
QUP core clock is put to 0 from other SE drivers before real console comes
up.

As earlycon can't vote for it's QUP core need, to fix this add ICC
support to common/QUP wrapper driver and put vote for QUP core from
probe on behalf of earlycon and remove vote during earlycon exit call.
Signed-off-by: NAkash Asthana <akashast@codeaurora.org>
Reported-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/1592908737-7068-3-git-send-email-akashast@codeaurora.orgSigned-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Implement the read() function in the early console driver.  With
recent kgdb patches this allows you to use kgdb to debug fairly early
into the system boot.

We only bother implementing this if polling is enabled since kgdb
can't be enabled without that.
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20200507130644.v4.10.If2deff9679a62c1ce1b8f2558a8635dc837adf8c@changeidSigned-off-by: NDaniel Thompson <daniel.thompson@linaro.org>

To support BT use case over UART at baud rate of 3.2 Mbps,
we need SE clocks to run at 51.2MHz frequency. Previously this
frequency was not available in clk src, so, we were requesting
for 102.4 MHz and dividing it internally by 2 to get 51.2MHz.

As now 51.2MHz frequency is made available in clk src,
adding this frequency to UART frequency table.

We will save significant amount of power, if 51.2 is used
because it belongs to LowSVS range whereas 102.4 fall into
Nominal category.
Signed-off-by: Nsatya priya <skakit@codeaurora.org>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/1590747282-5487-1-git-send-email-skakit@codeaurora.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 3d9231e6

Rajendra writes:

	Greg, there are other patches in the series which have a
	dependency on this patch [1] would it be possible for you to
	drop this patch and instead ack it so it can be taken via the
	msm tree?

So dropping it from here.
Reported-by: NRajendra Nayak <rnayak@codeaurora.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Akash Asthana <akashast@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

geni serial needs to express a perforamnce state requirement on CX
powerdomain depending on the frequency of the clock rates.
Use OPP table from DT to register with OPP framework and use
dev_pm_opp_set_rate() to set the clk/perf state.
Signed-off-by: NRajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Akash Asthana <akashast@codeaurora.org>
Cc: linux-serial@vger.kernel.org
Link: https://lore.kernel.org/r/1588507469-31889-2-git-send-email-rnayak@codeaurora.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The geni serial driver's shutdown code had a special case to call
console_stop().  Grepping through the code, it was the only serial
driver doing something like this (the only other caller of
console_stop() was in serial_core.c).

As far as I can tell there's no reason to call console_stop() in the
geni code.  ...and a good reason _not_ to call it.  Specifically if
you have an agetty running on the same serial port as the console then
killing the agetty kills your console and if you start the agetty
again the console doesn't come back.

Fixes: c4f52879 ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200313134635.2.I3648fac6c98b887742934146ac2729ecb7232eb1@changeidSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On a board using qcom_geni_serial I found that I could no longer
interact with kdb if I got a crash after the "agetty" running on the
same serial port was killed.  This meant that various classes of
crashes that happened at reboot time were undebuggable.

Reading through the code, I couldn't figure out why qcom_geni_serial
felt the need to run so much code at port shutdown time.  All we need
to do is disable the interrupt.

After I make this change then a hardcoded kgdb_breakpoint in some late
shutdown code now allows me to interact with the debugger.  I also
could freely close / re-open the port without problems.

Fixes: c4f52879 ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200313134635.1.Icf54c533065306b02b880c46dfd401d8db34e213@changeidSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To fix the RX cancel command failure, rx_fifo buffer needs to be
flushed in stop_rx() by calling handle_rx().In handle_rx() the data
in rx_fifo buffer is read and then dropped, not sent to upper layers.

If set_termios is called before startup, by this time memory is not
allocated to port->rx_fifo buffer, which leads to a NULL pointer
dereference.

To avoid this NULL pointer dereference allocate memory to port->rx_fifo
in probe itself.
Signed-off-by: Nsatya priya <skakit@codeaurora.org>
Reported-by: NStephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1583477228-32231-2-git-send-email-skakit@codeaurora.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add capability to support RX-TX, CTS-RTS pins swap in HW.

Configure UART_IO_MACRO_CTRL register accordingly if RX-TX pair
or CTS-RTS pair or both pairs swapped.
Signed-off-by: NRoja Rani Yarubandi <rojay@codeaurora.org>
Reviewed-by: NStephen Boyd <swboyd@chromium.org>
Tested-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/20200304112203.408-1-rojay@codeaurora.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

RX cancel command fails when BT is switched on and off multiple times.

To handle this, poll for the cancel bit in SE_GENI_S_IRQ_STATUS register
instead of SE_GENI_S_CMD_CTRL_REG.

As per the HPG update, handle the RX last bit after cancel command
and flush out the RX FIFO buffer.
Signed-off-by: Nsatya priya <skakit@codeaurora.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1581415982-8793-1-git-send-email-skakit@codeaurora.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove code from the driver that create and maintain loopback sysfs node.
Instead use the ioctl TIOCMSET with TIOCM_LOOP argument to set HW to
loopback mode.
Signed-off-by: NAkash Asthana <akashast@codeaurora.org>
Reviewed-by: NStephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1578321905-25843-3-git-send-email-akashast@codeaurora.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch is the continuation of below mentioned commits which adds wakeup
feature over the UART RX line.
1)commit 3e4aaea7 ("tty: serial: qcom_geni_serial: IRQ cleanup")[v2]
2)commit 8b7103f3 ("tty: serial: qcom_geni_serial: Wakeup over UART
  RX")[v2]

The following cleanup is done based on upstream comment received on
subsequent versions of the above-mentioned commits to simplifying the code.
 - Use devm_kasprintf API in place of scnprintf.
 - Use dev_pm_set_dedicated_wake_irq API that will take care of
   requesting and attaching wakeup irqs for devices. Also, it sets wakeirq
   status to WAKE_IRQ_DEDICATED_ALLOCATED as a result enabling/disabling of
   wake irq will be managed by suspend/resume framework. We can remove the
   code for enabling and disabling of wake irq from the this driver.
 - Use platform_get_irq_optional API to get optional wakeup IRQ for
   device.
 - Move ISR registration later in probe after uart port gets register with
   serial core.

Patch link:
 - https://patchwork.kernel.org/patch/11189717/ (v3)
 - https://patchwork.kernel.org/patch/11227435/ (v4)
 - https://patchwork.kernel.org/patch/11241669/ (v5)
 - https://patchwork.kernel.org/patch/11258045/ (v6)
Signed-off-by: NAkash Asthana <akashast@codeaurora.org>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NStephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1578321905-25843-2-git-send-email-akashast@codeaurora.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The SUPPORT_SYSRQ ifdeffery is not nice as:
- May create misunderstanding about sizeof(struct uart_port) between
  different objects
- Prevents moving functions from serial_core.h
- Reduces readability (well, it's ifdeffery - it's hard to follow)

In order to remove SUPPORT_SYSRQ, has_sysrq variable has been added.
Initialise it in driver's probe and remove ifdeffery.

Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: linux-arm-msm@vger.kernel.org
Signed-off-by: NDmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-36-dima@arista.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add system wakeup capability over UART RX line for wakeup capable UART.
When system is suspended, RX line act as an interrupt to wakeup system
for any communication requests from peer.
Signed-off-by: NAkash Asthana <akashast@codeaurora.org>
Link: https://lore.kernel.org/r/1570700803-17566-1-git-send-email-akashast@codeaurora.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Move ISR registration from startup to probe function to avoid registering
it everytime when the port open is called for driver.
Signed-off-by: NAkash Asthana <akashast@codeaurora.org>
Link: https://lore.kernel.org/r/1570700763-17319-1-git-send-email-akashast@codeaurora.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use devm_platform_ioremap_resource() to simplify the code a bit.
This is detected by coccinelle.
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20190802130817.16220-1-yuehaibing@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For QUP IP versions 2.5 and above the oversampling rate is halved
from 32 to 16. Update this rate after reading hardware version
register, so that the clock divider value is correctly set to
achieve required baud rate.
Signed-off-by: NVivek Gautam <vivek.gautam@codeaurora.org>
Link: https://lore.kernel.org/r/20190801121153.10613-1-vivek.gautam@codeaurora.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.

// <smpl>
@@
expression ret;
struct platform_device *E;
@@

ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);

if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>

While we're here, remove braces on if statements that only have one
statement (manually).

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NStephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20190730181557.90391-45-swboyd@chromium.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When building with -Wsometimes-uninitialized, Clang warns:

drivers/tty/serial/qcom_geni_serial.c:1079:6: warning: variable 'baud'
is used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]

It's not wrong; when options is NULL, baud has no default value. Use
9600 as that is a sane default.

Link: https://github.com/ClangBuiltLinux/linux/issues/395Suggested-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The geni set/get_mctrl() functions currently do nothing unless
hardware flow control is enabled. Remove this arbitrary limitation.
Suggested-by: NJohan Hovold <johan@kernel.org>
Fixes: 8a8a66a1 ("tty: serial: qcom_geni_serial: Add support for flow control")
Signed-off-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use u32 rather than unsigned long for register variables for clarity and
consistency.
Signed-off-by: NRyan Case <ryandcase@chromium.org>
Reviewed-by: NStephen Boyd <swboyd@chromium.org>
Reviewed-by: NEvan Green <evgreen@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The driver only supports FIFO mode so setting and checking this variable
is unnecessary. If DMA support is ever added then such checks can be
introduced.
Signed-off-by: NRyan Case <ryandcase@chromium.org>
Reviewed-by: NEvan Green <evgreen@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The variables of tx_wm and rx_wm were set to the same define value in
all cases, never updated, and the define was sometimes used
interchangably. Remove the variables/function and use the fixed value.
Signed-off-by: NRyan Case <ryandcase@chromium.org>
Reviewed-by: NEvan Green <evgreen@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A frequent side comment has been to remove the use of writel_relaxed,
readl_relaxed, and mb. This reduces driver complexity and the _relaxed
variants were not known to provide any noticeable performance benefit.
Signed-off-by: NRyan Case <ryandcase@chromium.org>
Reviewed-by: NEvan Green <evgreen@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If a serial console write occured while a UART transmit command was
waiting for a done signal then no further data would be sent until
something new kicked the system into gear. If there is already data
waiting in the circular buffer we must re-enable the tx watermark so we
receive the expected interrupts.
Signed-off-by: NRyan Case <ryandcase@chromium.org>
Reviewed-by: NEvan Green <evgreen@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Before commit a1fee899 ("tty: serial: qcom_geni_serial: Fix
softlock") the size of TX transfers was limited to the TX FIFO size,
and wrap arounds of the UART circular buffer were split into two
transfers. With the commit wrap around are allowed within a transfer.
The TX FIFO of the geni serial port uses a word size of 4 bytes. In
case of a circular buffer wrap within a transfer the driver currently
may write an incomplete word to the FIFO, with some bytes containing
data from the circular buffer and others being zero. Since the
transfer isn't completed yet the zero bytes are sent as if they were
actual data.

Handle wrap arounds of the TX buffer properly and ensure that words
written to the TX FIFO always contain valid data (unless the transfer
is completed).

Fixes: a1fee899 ("tty: serial: qcom_geni_serial: Fix softlock")
Signed-off-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NEvan Green <evgreen@chromium.org>
Tested-by: NRyan Case <ryandcase@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Disable M_TX_FIFO_WATERMARK_EN after we've sent all data for a given
transaction so we don't continue to receive a flurry of free space
interrupts while waiting for the M_CMD_DONE notification. Re-enable the
watermark when establishing the next transaction.

Also clear the watermark interrupt after filling the FIFO so we do not
receive notification again prior to actually having free space.
Signed-off-by: NRyan Case <ryandcase@chromium.org>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Transfers were being divided into device FIFO sized (64 byte max)
operations which would poll for completion within a spin_lock_irqsave /
spin_unlock_irqrestore block. This both made things slow by waiting for
the FIFO to completely drain before adding further data and would also
result in softlocks on large transmissions.

This patch allows larger transfers with continuous FIFO additions as
space becomes available and removes polling from the interrupt handler.
Signed-off-by: NRyan Case <ryandcase@chromium.org>
Reviewed-by: NStephen Boyd <swboyd@chromium.org>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Let's take advantage of the new ("serial: core: Allow processing sysrq
at port unlock time") to handle sysrqs more cleanly.
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The geni serial driver already had some sysrq code in it, but since
SUPPORT_SYSRQ wasn't defined the code didn't do anything useful.
Let's make it useful by adding that define using the same formula
found in other serial drivers.

In order to prevent deadlock, we'll take a page from the
'msm_serial.c' where the spinlock is released around
uart_handle_sysrq_char().  This seemed better than copying from
'8250_port.c' where we skip locking in the console_write function
since the '8250_port.c' method can cause lockdep warnings when
dropping into kgdb.
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should get 'driver_data' from 'struct device' directly. Going via
platform_device is an unneeded step back and forth.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

UART driver checks for the PM state and denies suspend if state is ACTIVE.
This makes UART to deny suspend when client keeps port open which is not
correct. Instead follow framework and obey suspend-resume callbacks.
Signed-off-by: NMukesh Kumar Savaliya <msavaliy@codeaurora.org>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If you turn on CONFIG_KGDB then you'll get CONFIG_CONSOLE_POLL
selected.

If you have CONFIG_CONSOLE_POLL selected then the GENI serial driver
was setting RX_BYTES_PW to 1 for _all_ UART ports.

This doesn't seem like such a good idea.  Let's only set RX_BYTES_PW
to 1 for the console port.
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NMukesh Kumar Savaliya <msavaliy@codeaurora.org>
Reviewed-by: NStephen Boyd <swboyd@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As done treewide earlier, this catches several more open-coded
allocation size calculations that were added to the kernel during the
merge window. This performs the following mechanical transformations
using Coccinelle:

	kvmalloc(a * b, ...) -> kvmalloc_array(a, b, ...)
	kvzalloc(a * b, ...) -> kvcalloc(a, b, ...)
	devm_kzalloc(..., a * b, ...) -> devm_kcalloc(..., a, b, ...)
Signed-off-by: NKees Cook <keescook@chromium.org>

If you've got the "console" serial port setup to use just as a UART
(AKA there is no "console=ttyMSMX" on the kernel command line) then
certain initialization is skipped.  When userspace later tries to do
something with the port then things go boom (specifically, on my
system, some sort of exception hit that caused the system to reboot
itself w/ no error messages).

Let's cleanup / refactor the init so that we always run the same init
code regardless of whether we're using the console.

To make this work, we make rely on qcom_geni_serial_pm doing its job
to turn resources on.

For the record, here is a trace of the order of things (after this
patch) when console= is specified on the command line and we have an
agetty on the port:
  qcom_geni_serial_pm: 4 (undefined) => 0 (on)
  qcom_geni_console_setup
  qcom_geni_serial_port_setup
  qcom_geni_serial_console_write
  qcom_geni_serial_startup
  qcom_geni_serial_start_tx

...and here is the order of things (after this patch) when console= is
_NOT_ specified on the command line and we have an agetty port:
  qcom_geni_serial_pm: 4 => 0
  qcom_geni_serial_pm: 0 => 3
  qcom_geni_serial_pm: 3 => 0
  qcom_geni_serial_startup
  qcom_geni_serial_port_setup
  qcom_geni_serial_pm: 0 => 3
  qcom_geni_serial_pm: 3 => 0
  qcom_geni_serial_startup
  qcom_geni_serial_start_tx

Fixes: c4f52879 ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With gcc 4.1.2:

    drivers/tty/serial/qcom_geni_serial.c: In function ‘qcom_geni_serial_probe’:
    drivers/tty/serial/qcom_geni_serial.c:1261: warning: ‘drv’ may be used uninitialized in this function

Indeed, if dev.of_node is NULL, drv will be used uninitialized, and
dereferenced in uart_add_one_port().  However, as this driver supports
DT only, dev.of_node will always be valid.

Hence remove the useless check for dev.of_node, killing the warning as a
side effect.

Fixes: 8a8a66a1 ("tty: serial: qcom_geni_serial: Add support for flow control")
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>