It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/tty files files with the correct SPDX license
identifier based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Jiri Slaby <jslaby@suse.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Joachim Eastwood <manabian@gmail.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Alexander Shiyan <shc_work@mail.ru>
Cc: Baruch Siach <baruch@tkos.co.il>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: "Uwe Kleine-König" <kernel@pengutronix.de>
Cc: Pat Gefre <pfg@sgi.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: Sylvain Lemieux <slemieux.tyco@gmail.com>
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: David Brown <david.brown@linaro.org>
Cc: "Andreas Färber" <afaerber@suse.de>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Timur Tabi <timur@tabi.org>
Cc: Tony Prisk <linux@prisktech.co.nz>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Move the request_irq() call to the end of the msm_startup(),
so that we don't handle interrupts while msm_startup() is
running. This avoids potential races while initialization
is in progress. For example, consider below scenario
where rx handler reads the intermediate value of dma->chan,
set in msm_request_rx_dma(), and tries to do dma mapping,
which results in data abort.

uart_port_startup()
  msm_startup()
   request_irq()
   ...
   msm_request_rx_dma()
    ...
    dma->chan = dma_request_slave_channel_reason(dev, "rx");
    <UART RX IRQ>
     msm_uart_irq()
      msm_handle_rx_dm()
       msm_start_rx_dma()
        dma->desc = dma_map_single()
         <data abort>
Signed-off-by: NNeeraj Upadhyay <neeraju@codeaurora.org>
Reviewd-by: NAndy Gross <andy.gross@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.

Export the module alias information using the MODULE_DEVICE_TABLE() macro.

Before this patch:

$ modinfo drivers/tty/serial/msm_serial.ko | grep alias
$

After this patch:

$ modinfo drivers/tty/serial/msm_serial.ko | grep alias
alias:          of:N*T*Cqcom,msm-uartdmC*
alias:          of:N*T*Cqcom,msm-uartdm
alias:          of:N*T*Cqcom,msm-uartC*
alias:          of:N*T*Cqcom,msm-uart
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The msm_stop_dma() is not exported from the driver, so make
it static to stop the following warning:

drivers/tty/serial/msm_serial.c:84:6: warning: symbol 'msm_stop_dma' was not declared. Should it be static?
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Acked-by: NAndy Gross <andy.gross@linaro.org>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For dm uarts in pio mode tx data is transferred to the fifo register 4
bytes at a time, but care is not taken when these 4 bytes spans the end
of the xmit buffer so the loop might read up to 3 bytes past the buffer
and then skip the actual data at the beginning of the buffer.

Fix this by, analogous to the DMA case, make sure the chunk doesn't
wrap the xmit buffer.

Fixes: 3a878c43 ("tty: serial: msm: Add TX DMA support")
Cc: Ivan Ivanov <iivanov.xz@gmail.com>
Cc: stable@vger.kernel.org
Reported-by: NFrank Rowand <frowand.list@gmail.com>
Reported-by: NNicolas Dechesne <nicolas.dechesne@linaro.org>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: NAndy Gross <andy.gross@linaro.org>
Tested-by: NFrank Rowand <frank.rowand@am.sony.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Avoid data corruption issues that result in CRC errors during file
transfers over serial ports at higher baud rates.

The current msm_serial driver masks the FIFO Rx interrupts in
msm_start_rx_dma() since Rx FIFO interrupts are not required in DMA
mode. However, msm_complete_rx_dma() re-enables the Rx FIFO interrupts
which could cause RXSTALE event to be processed when a TXLEV interrupt
occurs.

The following is the sequence of events that could occur resulting in
data corruption.

msm_start_rx_dma -> msm_complete_rx_dma -->
spin_unlock_irqrestore(&port->lock) -->
msm_uart_irq()(For TXLEV interrupt) -->  msm_handle_rx_dm() (Read from
FIFO resulting in data corruption)

The patch fixes the issue by not restoring the RXLEV and RXSTALE
interrupts in msm_complete_rx_dma(). These interrupts are required only
in FIFO mode.
Signed-off-by: NCharanya Venkatraman <charanya@codeaurora.org>
Acked-by: NAndy Gross <andy.gross@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The hrtimer include isn't used and neither is serial. Drop those
ones. The irq.h header really should be interrupt.h because this
is an interrupt user and not an interrupt chip. Finally add
wait.h for the wake_up*() usage in this driver and kernel.h for
container_of().
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NAndy Gross <andy.gross@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The registers that msm_serial_set_mnd_regs() writes only exist on
the non-uartdm hardware, so let's return early here if this
function is called on uartdm hardware. This also prevents us from
messing up the uartclk variable if the uartclk rate happens to be
19.2 or 4.8 MHz.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NAndy Gross <andy.gross@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This header file is only used by the driver, so let's merge the
two together to reduce files and make it easier to see the whole
driver without flipping through two files. This also makes it
easier to use the structures defined in msm_serial.c in the
functions that are defined in msm_serial.h by placing them in the
proper locations.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NAndy Gross <andy.gross@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The msm_find_best_baud() function is written with the assumption
that the port->uartclk rate is fixed to a particular rate at boot
time, but now this driver changes that clk rate at runtime when
the baud is changed.

The way the hardware works is that an input clk rate comes from
the clk controller into the uart hw block. That rate is typically
1843200 or 3686400 Hz. That rate can then be divided by an
internal divider in the hw block to achieve a particular baud on
the serial wire. msm_find_best_baud() is looking for that divider
value.

A few things are wrong with the way the code is written. First,
it assumes that the maximum baud that the uart can support if the
clk rate is fixed at boot is 460800, which would correspond to an
input clk rate of 230400 * 16 == 3686400 Hz.  Except some devices
have a boot rate of 1843200 Hz or max baud of 115200, so
achieving 230400 on those devices doesn't work at all because we
don't increase the clk rate unless max baud is 460800.

Second, we can't achieve bauds higher than 460800 that require
anything besides a divisor of 1, because we always call
msm_find_best_baud() with a fixed port->uartclk rate that will
eventually be changed after we calculate the divisor. So if we
need to get a baud of 500000, we'll just multiply that by 16 and
hope that the clk can give us 500000 * 16 == 8000000 Hz, which it
typically can't do. To really achieve 500000 baud, we need to get
an input clk rate of 24000000 Hz and then divide that by 3 inside
the uart hardware.

Finally, we return success for bauds even when we can't actually
achieve them. This means that when the user asks for 500000 baud,
we actually get 921600 right now, but the user doesn't know that.

Fix all of this by searching through the divisor and clk rate
space with a combination of clk_round_rate() and baud
calculations, keeping track of the best clk rate and divisor we
find if we can't get an exact match. Typically we can get an
exact match with a divisor of 1, but sometimes we need to keep
track and try more frequencies. On my msm8916 device, this
results in all standard bauds in baud_table being supported
except for 1800, 576000, 1152000, and 4000000.

Fixes: 850b37a7 ("tty: serial: msm: Remove 115.2 Kbps maximum baud rate limitation")
Cc: "Ivan T. Ivanov" <iivanov.xz@gmail.com>
Cc: Matthew McClintock <mmcclint@codeaurora.org>
Signed-off-by: NStephen Boyd <stephen.boyd@linaro.org>
Tested-by: NSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: NAndy Gross <andy.gross@linaro.org>
Acked-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Tested-by: NCristian Prundeanu <cprundea@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The issue with setting up a fixed clock rate at probe is that it would
overwrite the console rate set by the bootloader for its console device.
This would result in serial out corruption or missing log when we system
is booted with earlycon. This is not a issue if we boot system without
earlycon.

This setup is at least not required with the mainline driver, this code
used to be required because the clk_enable() call would fail if
clk_set_rate() wasn't called first.

Originally the issue was noticed on DB410c which is based on APQ8016
chipset.

Without this patch the console log with earlycon would look like:
...
[    0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=64, nr_cpu_ids=1
[    0.000000] NR_IRQS:64 nr_irqs:64 0
����+HH��0.699378] console [ttyMSM0] enabled
[    0.699378] console [ttyMSM0] enabled
[    0.702003] bootconsole [uart0] disabled
[    0.702003] bootconsole [uart0] disabled
...

with this patch I can see all the skipped lines on the console
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: NAndy Gross <andy.gross@linaro.org>
Tested-by: NPramod Gurav <gpramod@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use a single common table of struct earlycon_id for both command line
and devicetree. Re-define OF_EARLYCON_DECLARE() macro to instance a
unique earlycon declaration (the declaration is only guaranteed to be
unique within a compilation unit; separate compilation units must still
use unique earlycon names).

The semantics of OF_EARLYCON_DECLARE() is different; it declares an
earlycon which can matched either on the command line or by devicetree.
EARLYCON_DECLARE() is semantically unchanged; it declares an earlycon
which is matched by command line only. Remove redundant instances of
EARLYCON_DECLARE().

This enables all earlycons to properly initialize struct console
with the appropriate name and index, which improves diagnostics and
enables direct earlycon-to-console handoff.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

UART controller is capable to perform transfers up to 4 Mbps.
Remove artificial 115.2 Kbps limitation.
Signed-off-by: NIvan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add receive DMA support for UARTDM type of controllers.

Tested on APQ8064, which have UARTDM v1.3 and ADM DMA engine
and APQ8016, which have UARTDM v1.4 and BAM DMA engine.
Signed-off-by: NIvan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add transmit DMA support for UARTDM type of controllers.

Tested on APQ8064, which have UARTDM v1.3 and ADM DMA engine
and APQ8016, which have UARTDM v1.4 and BAM DMA engine.
Signed-off-by: NIvan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make function naming consistent across this driver.
Also rename msm_irq to msm_uart_irq. No functional changes.
Signed-off-by: NIvan T. Ivanov <ivan.ivanov@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The bit masks for RFR_LEVEL1 and STALE_TIMEOUT_MSB values in MR1 and
IPR registers respectively are different for UART and UART_DM hardware
cores. We have been using UART core mask values for these. Add the same
for UART_DM core.

There is no bit setting as UART_IPR_RXSTALE_LAST for UART_DM core so do
it only for UART core.
Signed-off-by: NPramod Gurav <gpramod@codeaurora.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NIvan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

unregister_console() will be called from uart_remove_one_port() while
removing the platform driver. So not necessary to call it in driver
exit path.
Signed-off-by: NPramod Gurav <pramod.gurav@smartplayin.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The change does following:
 - baud, flow, bits, parity were being overwritten as they were
   being reinitialized after parsing.  Initialize them when they are
   declared so that user provided setting are not overwritten.
 - msm_set_baud_rate() is anyway called in uart_set_options when it calls
   msm_set_termios(). msm_reset() is called when we change the baud rate.
   Hence doing away with both of these calls.
 - CR_CMD_PROTECTION_EN and CR_TX_ENABLE settings are done in msm_set_baud_rate.
   So do away with this here.
Signed-off-by: NPramod Gurav <pramod.gurav@smartplayin.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If there isn't a DT alias then of_alias_get_id() will return
-ENODEV. This will cause the msm_serial driver to fail probe,
when we want to keep the previous behavior where we generated a
dynamic line number at probe time. Restore this behavior by
generating a dynamic id if the line number is still negative
after checking for an alias or in the non-DT case looking at the
.id field of the platform device.
Reported-by: NKevin Hilman <khilman@kernel.org>
Tested-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We rely on probe order of this driver to determine the line number for
the uart port. This makes it impossible to know the line number
when these devices are populated via DT. Use the DT alias
mechanism to assign the line based on the aliases node.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We need to issue a reset if we ever change the value of the IPR
register on DM hardware. If we don't reset the hardware the RX
stale interrupt never triggers and the only way to trigger an RX
handling event is by filling up the fifo. This causes things like
getty to not work so well considering it might change the baud
rate a few times. Fix this by moving the reset on startup and any
reprogramming required after the reset to be after we change the
baud rate.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To properly support sysrq on uartDM hardware we need to properly
handle break characters. With the DM hardware the fifo can pack 4
characters at a time, where a break is indicated by an all zero
byte. Unfortunately, we can't differentiate between an all zero
byte for a break and an all zero byte of data, so try and do as
best we can. First unmask the RX break start interrupt and record
the interrupt when it arrives. Then while processing the fifo,
detect the break by searching for an all zero character as long
as we recently received an RX break start interrupt. This should
make sysrq work fairly well.

Cc: Frank Rowand <frank.rowand@sonymobile.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The handle_rx() path calls uart_handle_sysrq_char() with the port
lock held. This causes a spinlock recursion. Release and
reacquire the lock here to avoid this.

BUG: spinlock recursion on CPU#0, swapper/0
 lock: msm_uart_ports+0x1e0/0x2d0, .magic: dead4ead, .owner: swapper/0, .owner_cpu: 0
CPU: 0 PID: 0 Comm: swapper Not tainted 3.17.0-rc7-00012-gb38ee8265941 #69
[<c0013964>] (unwind_backtrace) from [<c0011f74>] (show_stack+0x10/0x14)
[<c0011f74>] (show_stack) from [<c004ed1c>] (do_raw_spin_lock+0x11c/0x13c)
[<c004ed1c>] (do_raw_spin_lock) from [<c02d44c0>] (msm_console_write+0x78/0x188)
[<c02d44c0>] (msm_console_write) from [<c0052880>] (call_console_drivers.constprop.22+0xb4/0x144)
[<c0052880>] (call_console_drivers.constprop.22) from [<c0053570>] (console_unlock+0x27c/0x4ac)
[<c0053570>] (console_unlock) from [<c0053bb4>] (vprintk_emit+0x1f4/0x5a8)
[<c0053bb4>] (vprintk_emit) from [<c04ad0ac>] (printk+0x30/0x40)
[<c04ad0ac>] (printk) from [<c02c2990>] (__handle_sysrq+0x58/0x1b8)
[<c02c2990>] (__handle_sysrq) from [<c02d41b0>] (msm_irq+0x694/0x6f8)
[<c02d41b0>] (msm_irq) from [<c0055740>] (handle_irq_event_percpu+0x58/0x270)
[<c0055740>] (handle_irq_event_percpu) from [<c0055994>] (handle_irq_event+0x3c/0x5c)
[<c0055994>] (handle_irq_event) from [<c0057e84>] (handle_level_irq+0x9c/0x138)
[<c0057e84>] (handle_level_irq) from [<c005509c>] (generic_handle_irq+0x24/0x38)
[<c005509c>] (generic_handle_irq) from [<c000f730>] (handle_IRQ+0x44/0xb0)
[<c000f730>] (handle_IRQ) from [<c0008518>] (msm_vic_handle_irq+0x44/0x64)
[<c0008518>] (msm_vic_handle_irq) from [<c04b5ac4>] (__irq_svc+0x44/0x7c)
Exception stack(0xc0719f68 to 0xc0719fb0)
9f60:                   00000001 00000001 00000000 c0722938 c0718000 c0769acc
9f80: 00000000 c0720098 c0769305 4117b362 c0769acc 00000000 01000000 c0719fb0
9fa0: c004cab0 c000f880 20000013 ffffffff
[<c04b5ac4>] (__irq_svc) from [<c000f880>] (arch_cpu_idle+0x20/0x30)
[<c000f880>] (arch_cpu_idle) from [<c004691c>] (cpu_startup_entry+0xf4/0x23c)
[<c004691c>] (cpu_startup_entry) from [<c06d8b70>] (start_kernel+0x32c/0x394)

Cc: Frank Rowand <frank.rowand@sonymobile.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A platform_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Add support for DT based and command line based early console on platforms
with the msm serial hardware.

Cc: Rob Herring <robh@kernel.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Frank reports that after continuing in kgdb the RX stale event
doesn't occur until after the RX fifo is filled up with exactly
the amount of characters programmed for the RX watermark (in this
case it's 48). To read a single character from the uartdm
hardware we force a stale event so that any characters in the RX
packing buffer are flushed into the RX fifo immediately instead
of waiting for a stale timeout or for the fifo to fill. Forcing
that stale event asserts the stale interrupt but we never clear
that interrupt via UART_CR_CMD_RESET_STALE_INT in the polling
functions. So when kgdb continues the stale interrupt is left
pending in the hardware and we don't timeout with a stale event,
like we usually would if a user typed one character on the
console, until the reset stale interrupt and stale event commands
are sent. Frank could get things working again by running
handle_rx_dm(). By putting enough characters into the fifo he
could trigger a watermark interrupt, and thus cause
handle_rx_dm() to run finally resetting the stale interrupt
and enabling the stale event so that single characters would
cause timeouts again.

The fix is to just do what the interrupt routine was doing all
along and clear the stale interrupt and enable the event again.
Doing this also smooths over any differences in the fifo behavior
between v1.3 and v1.4 hardware allowing us to skip forcing the
uart into single character mode.
Reviewed-by: NFrank Rowand <frank.rowand@sonymobile.com>
Tested-by: NFrank Rowand <frank.rowand@sonymobile.com>
Fixes: f7e54d7a "msm_serial: Add support for poll_{get,put}_char()"
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

fixed below checkpatch.pl warning:

WARNING: void function return statements are not generally useful
Signed-off-by: NKiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

fixed below checkpatch.pl warning:

WARNING: else is not generally useful after a break or return
Signed-off-by: NKiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

fixed below checkpatch.pl warning:

WARNING: Prefer [subsystem eg: netdev]_err([subsystem]dev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

WARNING: Prefer [subsystem eg: netdev]_info([subsystem]dev, ... then dev_info(dev, ... then pr_info(...  to printk(KERN_INFO ...
Signed-off-by: NKiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes below checkpatch.pl warning and it remove extra blank lines:

WARNING: Missing a blank line after declarations
Signed-off-by: NKiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

fixed below checkpatch.pl warning:

WARNING: braces {} are not necessary for any arm of this statement
Signed-off-by: NKiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make of_device_id array const, because all OF functions handle it as const.
Signed-off-by: NKiran Padwal <kiran.padwal@smartplayin.com>
Acked-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To support big-endian CPUs use the string versions of the io
read/write macros on the TX/RX fifos and the non-raw variants of
the readl/writel macros throughout. This way we don't byteswap
the characters coming from the fifos but we properly deal with
the little-endian nature of the serial hardware while controlling
it.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is a risk that the variable will be used without being initialized.

This was largely found by using a static code analysis program called cppcheck.
Signed-off-by: NRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If IGNBRK is set without either BRKINT or PARMRK set, some uart
drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the
line discipline, when it should send either nothing or the TTYBREAK flag
set. This happens because the read_status_mask masks out the BI
condition, which uart_insert_char() then interprets as a normal 0x00 byte.

SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General
Terminal Interface - Input Modes, states:
  "If IGNBRK is set, a break condition detected on input shall be ignored;
   that is, not put on the input queue and therefore not read by any
   process."

Fix read_status_mask to include the BI bit if IGNBRK is set; the
lsr status retains the BI bit if a BREAK is recv'd, which is
subsequently ignored in uart_insert_char() when masked with the
ignore_status_mask.

Affected drivers:
8250 - all
serial_txx9
mfd
amba-pl010
amba-pl011
atmel_serial
bfin_uart
dz
ip22zilog
max310x
mxs-auart
netx-serial
pnx8xxx_uart
pxa
sb1250-duart
sccnxp
serial_ks8695
sirfsoc_uart
st-asc
vr41xx_siu
zs
sunzilog
fsl_lpuart
sunsab
ucc_uart
bcm63xx_uart
sunsu
efm32-uart
pmac_zilog
mpsc
msm_serial
m32r_sio

Unaffected drivers:
omap-serial
rp2
sa1100
imx
icom

Annotated for fixes:
altera_uart
mcf

Drivers without break detection:
21285
xilinx-uartps
altera_jtaguart
apbuart
arc-uart
clps711x
max3100
uartlite
msm_serial_hs
nwpserial
lantiq
vt8500_serial

Unknown:
samsung
mpc52xx_uart
bfin_sport_uart
cpm_uart/core

Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag'
Reported-by: NIvan <athlon_@mail.ru>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

WARNING: drivers/tty/built-in.o(.data+0x3544): Section mismatch in
reference from the variable msm_platform_driver to the function
.init.text:msm_serial_probe()
The variable msm_platform_driver references
the function __init msm_serial_probe()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console
Signed-off-by: NKumar Gala <galak@codeaurora.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

This patch removes direct access of the GSBI registers.  GSBI configuration
should be done through the GSBI driver directly.
Signed-off-by: NAndy Gross <agross@codeaurora.org>
Signed-off-by: NKumar Gala <galak@codeaurora.org>

Implement the polling functionality for the MSM serial driver.
This allows us to use KGDB on this hardware.

Cc: David Brown <davidb@codeaurora.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We recently added support to send more than one character at a
time for UARTDM hardware but we didn't add the same support in
the console code path. Add support here to speed up console
messages on UARTDM hardware.

Cc: David Brown <davidb@codeaurora.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>