Add early console functionality to the Goldfish tty driver.

When 'earlycon' kernel command line parameter is used with no options,
the early console is determined by the 'stdout-path' property in device
tree's 'chosen' node. This is illustrated in the following device tree
source example:

Device tree example:

    chosen {
        stdout-path = "/goldfish_tty@1f004000";
    };

    goldfish_tty@1f004000 {
        interrupts = <0xc>;
        reg = <0x1f004000 0x0 0x1000>;
        compatible = "google,goldfish-tty";
    };
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Implement tty r/w operations using streaming DMA.

Goldfish tty for Ranchu platforms has been modified to use
streaming DMA mappings for read/write operations. This change
eliminates the need for snooping through the TLB in QEMU using
cpu_get_phys_page_debug() which does not guarantee that it will
return the valid va -> pa mapping.

The streaming DMA mapping is implemented using dma_map_single() per
transfer, while dma_unmap_single() is used for unmapping right after
the DMA transfer.

Using DMA API is the proper way for handling r/w transfers and
makes this driver more portable, thus effectively eliminating
the need for virt_to_page() and page_to_phys() conversions.

This change does not affect the old style Goldfish tty behaviour
which is still used by the Goldfish emulator. Version register has
been added and probed to see which platform is running this driver.
Reading from the new register GOLDFISH_TTY_REG_VERSION using the
Goldfish emulator will return 0 and driver will work with virtual
addresses. Whereas if run on Ranchu it returns 1, and thus DMA is
used.

(Goldfish and Ranchu are code names for the first and the second
generation of virtual boards used by Android emulator.)
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Classify constants GOLDFISH_TTY_xxx into two groups: command ids and
register offsets. Apply different naming for register offsets (add
'REG_' after 'GOLDFISH_TTY_' in constant names). Change implementation
to use preprocessor's '#define' statements instead of 'enum'
declaration (as this is more common way of implementation in such
cases).

This makes the driver code easier to follow and hopefully prevents
future bugs.
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

After switching to HR timers for RS485 the NULL checks for the object
inside timer functions become useless.

Remove them to avoid confusion to static analyzers.

Fixes 6e0a5de2 ("serial: 8250: Use hrtimers for rs485 delays")
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

For now baud field of earlycon structure device is't initialised at all
in of_setup_earlycon (in oppositе to register_earlycon).

So when I use stdout-path to point earlycon device
(like stdout-path = &serial or stdout-path = "serial:115200n8")
baud field of earlycon device structure remains uninitialised and
earlycon initialization is not performed correctly as
of_setup_earlycon is used.
When pass all arguments via bootargs
(like bootargs = "earlycon=uart8250,mmio32,0xf0005000,115200n8")
initialization is performed correctly as register_earlycon is used.

So initialise baud field of earlycon device structure by value of
"current-speed" property from device tree or from options
(if they exist) when we use of_setup_earlycon
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Make this const as it is not modified anywhere.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds "tty-index" field to /proc/PID/fdinfo/N if N
specifies /dev/ptmx. The field shows the index of associative
slave pts.

Though a minor number is given for each pts instance, ptmx is not.
It means there is no way in user-space to know the association between
file descriptors for pts/n and ptmx. (n = 0, 1, ...)

This is different from pipe. About pipe such association can be solved
by inode of pipefs.

Providing the way to know the association between pts/n and ptmx helps
users understand the status of running system. lsof can utilize this field.
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

To use this driver with 32 bit userspace applications on 64 bit
kernels a compat_ioctl is needed.
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vio_device_id are not supposed to change at runtime. All functions
working with vio_device_id provided by <asm/vio.h> work with
const vio_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vio_device_id are not supposed to change at runtime. All functions
working with vio_device_id provided by <asm/vio.h> work with
const vio_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mips_cdmm_device_id are not supposed to change at runtime.
mips_cdmm_driver is working with const 'id_table'. So mark
the non-const mips_cdmm_device_id structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch introduces the 8250_men_mcb driver for the MEN 16Z125
IP-Core. This is a 16550-type UART with a 60 byte FIFO.
Due to strange old hardware, every board using this IP core requires
different values for uartclk. A reasonable default is included in
addition to the support of three boards. Additional values for other
boards will be added later.

This v2 has some whitespace fixes, I screwed this up yesterday.
Signed-off-by: Michael Moese <michael.moese@men.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Introduce mcb_get_resource() as a common accessor to a mcb device's memory or
IRQ resources.
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The imx_transmit_buffer function should return if TX DMA has already
been started and not just skip over the buffer PIO write loop. (Which
did fix the initial problem, but could have unintentional side-effects)

Tested on an i.MX6Q board with half-duplex RS-485 and with RS-232.

Cc: Clemens Gruber <clemens.gruber@pqgruber.com>
Cc: Uwe-Kleine König <u.kleine-koenig@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Fixes: 514ab34d ("serial: imx: Prevent TX buffer PIO write when a DMA has been started")
Signed-off-by: Ian Jamison <ian.dev@arkver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If any key on console is pressed when board is suspended,
board hangs.

Driver's interrupt handler must be guaranteed not to run while
resume/suspend_noirq() are being executed. See include/linux/pm.h
for details.

Tested on i.MX6 based board.

The idea of this fix is based on commit in official i.MX kernel tree:
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git
commit 81e8e7d91d81 ("tty: serial: imx: disable irq after suspend")

Disable rx irq after suspend to avoid interrupt coming in early resume.
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Maxim Yu. Osipov <mosipov@ilbers.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add suspend/resume support for UniPhier serial driver.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The 8250 core uses the SCR as a canary to discover if the console has
been powered-off.

This hardware does not have SCR at offset 7, but an unused register
CHAR at a different offset.  As long as the character interrupt is
disabled, the register access has no impact, so it is useful as an
alternative scratch register.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial8250_register_8250_port() may allocate a different port index
than requested.  The driver needs to remember the returned value of
serial8250_register_8250_port() for later use.  Otherwise, the .remove
hook may unregister a different port.

Fixes: 1a8d2903 ("serial: 8250_uniphier: add UniPhier serial driver")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MediaTek BTIF controller is the serial interface similar to UART but it
works only as the digital device which is mainly used to communicate with
the connectivity module called CONNSYS inside the SoC which could be mostly
found on those MediaTek SoCs with Bluetooth feature such as MT7622 and
MT7623 SoCs.

And the controller is made as being compatible with the 8250 register
layout with extra registers such as DMA enablement so it tends to be
integrated with reusing 8250 OF driver. However, DMA mode is not being
supported yet in the current driver.
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Document the devicetree bindings in 8250.txt for MediaTek BTIF
controller which could be found on MT7622 and MT7623 SoC.
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When moving earlycon early_param handling to serial, the devicetree
earlycons enable condition changed slightly.

We used to only do that for 'console'/'earlycon', but now would also
for 'console='/'earlycon='.

Fix it by using the same condition like before.

Fixes: d503187b (of/serial: move earlycon early_param handling to serial)
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

These uart_ops structures are only stored in the ops field of a
uart_port structure and this fields is const, so the uart_ops
structures can also be const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

These uart_ops structures are only stored in the ops field of a
uart_port structure and this fields is const, so the uart_ops
structures can also be const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

These uart_ops structures are only stored in the ops field of a
uart_port structure and this fields is const, so the uart_ops
structures can also be const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

These uart_ops structures are only stored in the ops field of a
uart_port structure and this fields is const, so the uart_ops
structures can also be const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

These uart_ops structures are only stored in the ops field of a
uart_port structure and this fields is const, so the uart_ops
structures can also be const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

These uart_ops structures are only stored in the ops field of a
uart_port structure and this fields is const, so the uart_ops
structures can also be const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

These uart_ops structures are only stored in the ops field of a
uart_port structure and this fields is const, so the uart_ops
structures can also be const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

These uart_ops structures are only stored in the ops field of a
uart_port structure and this fields is const, so the uart_ops
structures can also be const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

These uart_ops structures are only stored in the ops field of a
uart_port structure and this fields is const, so the uart_ops
structures can also be const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Timur Tabi <timur@tabi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parisc_device_id are not supposed to change at runtime. All functions
working with parisc_device_id provided by <asm/parisc-device.h> work
with const parisc_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parisc_device_id are not supposed to change at runtime. All functions
working with parisc_device_id provided by <asm/parisc-device.h> work
with const parisc_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

66AK2G UART instances are not apart of the ALWAYS_ON power domain.
Therefore, pm_runtime calls must be made to properly insure the appropriate
power domains needed by UART are on. Keep legacy clk api calls since other
users of this driver may not support PM runtime.
Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use slightly more compact of_property_read_bool() calls for the boolean
properties instead of of_find_property() calls.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Previously the timers where based on the classic timers, giving a too
coarse resolution on systems with configs of less than 1000 HZ.

This patch changes the rs485 timers to hrtimers.
Signed-off-by: Rafael Gago Castano <rgc@hms.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Previously the rs485 settings weren't considered when setting the RTS
line, so e.g. closing and reopening a port made serial_core to drive
the line as if rs485 was disabled.

This patch fixes those issues.
Signed-off-by: Rafael Gago Castano <rgc@hms.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR
Signed-off-by: Himanshu Jha <himanshujha199640@gmail.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Document support for the (H)SCIF serial ports in the Renesas R-Car D3
(r8a77995) SoC.

No driver update is needed.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use more compact of_property_read_bool() call for a boolean property
instead  of of_find_property() call in sci_parse_dt().
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The UAPI has a global list of unique numbers for different port types.
The commit
	a2d6a987 ("serial: 8250: Add new port type for TI DA8xx/66AK2x")
introduced a new port type and brought the collision with two other port
types.

Reuse 95 for it instead.

Fixes: a2d6a987 ("serial: 8250: Add new port type for TI DA8xx/66AK2x")
Cc: David Lechner <david@lechnology.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>