Commit graph

2560 commits

Author SHA1 Message Date
Tobias Klauser
2fbe6c5e3e serial: altera_jtaguart: Fix putchar function passed to uart_console_write()
Commit 3d1c90d48c ("serial: altera_jtaguart: Adpot
uart_console_write()") introduced the usage of uart_console_write() but
didn't change the signature of altera_jtaguart_console_putc() to take a
pointer to struct uart_port instead of struct console, breaking the
driver's console support and leading to the following warning:

>    drivers/tty/serial/altera_jtaguart.c: In function 'altera_jtaguart_console_write':
> >> drivers/tty/serial/altera_jtaguart.c:350:2: warning: passing argument 4 of 'uart_console_write' from incompatible pointer type [enabled by default]
>      uart_console_write(port, s, count, altera_jtaguart_console_putc);
>      ^
>    In file included from drivers/tty/serial/altera_jtaguart.c:25:0:
>    include/linux/serial_core.h:317:6: note: expected 'void (*)(struct uart_port *, int)' but argument is of type 'void (*)(struct console *, int)'
>     void uart_console_write(struct uart_port *port, const char *s,

Fix this by adjusting the signature of altera_jtaguart_console_putc()
accordingly.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-22 16:34:33 -07:00
Yoshihiro YUNOMAE
aef9a7bd9b serial/uart/8250: Add tunable RX interrupt trigger I/F of FIFO buffers
Add tunable RX interrupt trigger I/F of FIFO buffers.

Serial devices are used as not only message communication devices but control
or sending communication devices. For the latter uses, normally small data
will be exchanged, so user applications want to receive data unit as soon as
possible for real-time tendency. If we have a sensor which sends a 1 byte data
each time and must control a device based on the sensor feedback, the RX
interrupt should be triggered for each data.

According to HW specification of serial UART devices, RX interrupt trigger
can be changed, but the trigger is hard-coded. For example, RX interrupt trigger
in 16550A can be set to 1, 4, 8, or 14 bytes for HW, but current driver sets
the trigger to only 8bytes.

This patch makes some devices change RX interrupt trigger from userland.

<How to use>
- Read current setting
 # cat /sys/class/tty/ttyS0/rx_trig_bytes
 8

- Write user setting
 # echo 1 > /sys/class/tty/ttyS0/rx_trig_bytes
 # cat /sys/class/tty/ttyS0/rx_trig_bytes
 1

<Support uart devices>
- 16550A and Tegra (1, 4, 8, or 14 bytes)
- 16650V2 (8, 16, 24, or 28 bytes)
- 16654 (8, 16, 56, or 60 bytes)
- 16750 (1, 16, 32, or 56 bytes)

<Change log>
Changes in V9:
 - Use attr_group instead of dev_spec_attr_group of uart_port structure

Changes in V8:
 - Divide this patch from V7's patch based on Greg's comment

Changes in V7:
 - Add Documentation
 - Change I/F name from rx_int_trig to rx_trig_bytes because the name
   rx_int_trig is hard to understand how users specify the value

Changes in V6:
 - Move FCR_RX_TRIG_* definition in 8250.h to include/uapi/linux/serial_reg.h,
   rename those to UART_FCR_R_TRIG_*, and use UART_FCR_TRIGGER_MASK to
   UART_FCR_R_TRIG_BITS()
 - Change following function names:
    convert_fcr2val() => fcr_get_rxtrig_bytes()
    convert_val2rxtrig() => bytes_to_fcr_rxtrig()
 - Fix typo in serial8250_do_set_termios()
 - Delete the verbose error message pr_info() in bytes_to_fcr_rxtrig()
 - Rename *rx_int_trig/rx_trig* to *rxtrig* for several functions or variables
   (but UI remains rx_int_trig)
 - Change the meaningless variable name 'val' to 'bytes' following functions:
    fcr_get_rxtrig_bytes(), bytes_to_fcr_rxtrig(), do_set_rxtrig(),
    do_serial8250_set_rxtrig(), and serial8250_set_attr_rxtrig()
 - Use up->fcr in order to get rxtrig_bytes instead of rx_trig_raw in
   fcr_get_rxtrig_bytes()
 - Use conf_type->rxtrig_bytes[0] instead of switch statement for support check
   in register_dev_spec_attr_grp()
 - Delete the checking whether a user changed FCR or not when minimum buffer
   is needed in serial8250_do_set_termios()

Changes in V5.1:
 - Fix FCR_RX_TRIG_MAX_STATE definition

Changes in V5:
 - Support Tegra, 16650V2, 16654, and 16750
 - Store default FCR value to up->fcr when the port is first created
 - Add rx_trig_byte[] in uart_config[] for each device and use rx_trig_byte[]
   in convert_fcr2val() and convert_val2rxtrig()

Changes in V4:
 - Introduce fifo_bug flag in uart_8250_port structure
   This is enabled only when parity is enabled and UART_BUG_PARITY is enabled
   for up->bugs. If this flag is enabled, user cannot set RX trigger.
 - Return -EOPNOTSUPP when it does not support device at convert_fcr2val() and
   at convert_val2rxtrig()
 - Set the nearest lower RX trigger when users input a meaningless value at
   convert_val2rxtrig()
 - Check whether p->fcr is existing at serial8250_clear_and_reinit_fifos()
 - Set fcr = up->fcr in the begging of serial8250_do_set_termios()

Changes in V3:
 - Change I/F from ioctl(2) to sysfs(rx_int_trig)

Changed in V2:
 - Use _IOW for TIOCSFIFORTRIG definition
 - Pass the interrupt trigger value itself

Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:23:35 -07:00
Greg Kroah-Hartman
266dcff03e Serial: allow port drivers to have a default attribute group
Some serial drivers (like 8250), want to add sysfs files.  We need to do
so in a race-free way, so allow any port to be able to specify an
attribute group that should be added at device creation time.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:21:21 -07:00
Daniel Thompson
c8b29f049e tty: kgdb_nmi: Automatically manage tty enable
At present it is not possible to boot with the ttyNMI0 console treating
character input normally, instead character input triggers a prompt
telling the user how to trigger the knock detector and enter the
debugger. To use the console normally requires that kdb be entered and
the nmi_console command be used to enable the console (or if only kgdb
is present then gdb must directly manipulate the value of
kgdb_nmi_tty_enabled).

This patch automates the management of kgdb_nmi_tty_enabled by keeping
track of the number of file handles that are open for reading and using
that to determine how to tty should operate.

The approach means that:

1. Behaviour before init starts is unchanged.

2. If the userspace runs a getty or some other interactive process on
   /dev/console (or explicitly on /dev/ttyNMI0) the tty will treat
   character input like any other tty.

3. If the userspace doesn't use /dev/console or if it uses /dev/console
   only to log messages (O_WRONLY) then the user prompt is retained.

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:19:40 -07:00
Tobias Klauser
3d1c90d48c serial: altera_jtaguart: Adpot uart_console_write()
Follow commit 2970b7f5ea ("serial: altera: Adopt
uart_console_write()") and don't open code the LF to LFCR conversion in
altera_jtaguart either. Use uart_console_write() instead.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:19:40 -07:00
Naveen Krishna Chatradhi
4622eb6873 serial: samsung: improve code clarity by defining a variable
The of_node is derived from pdev for every usage, define a
device_node variable instead.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:18:22 -07:00
Naveen Krishna Chatradhi
3bcce591aa serial: samsung: correct the case and default order in switch
The cases should comes before default in a switch.

Even if we want the case and default to share same code.
Its good to define the case first followed by default.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:18:22 -07:00
Naveen Krishna Chatradhi
135f07c325 serial: samsung: get fifosize via device tree
UART modules on some SoCs only differ in the fifosize of each
UART channel. Its useless to duplicate the drv_data structure
or create a compatible name for such a change.

We can get fifosize via the device tree nodes (not mandating it).

Also updates the documentation.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:18:22 -07:00
Andy Shevchenko
b1261c86fe serial: 8250: introduce up_to_u8250p() helper
It helps to cast struct uart_port to struct uart_8250_port at runtime.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:16:23 -07:00
Jingchang Lu
380c966c09 tty: serial: fsl_lpuart: add 32-bit register interface support
This add the 32-bit register version LPUART support with big-endian
byte order.

Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:15:38 -07:00
Nobuhiro Iwamatsu
730c4e782c serial: sh-sci: Add calculation recive margin for HSCIF
When the error of the same bit rate is detected, we will need to select
the recive margin is large. Current code holds the minimum error, it does
not have to check the recive margin. This adds this calculation.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:14:44 -07:00
Nobuhiro Iwamatsu
bcb9973a60 serial: sh-sci: Fix range check of bit-rate for HSCIF
If bit-rate calculation result of HSCIF is expect 255 from 0,
driver does not calculate error bit. However, we need to round
the value to calculate error bit in the case of negative value.
This rounds the value of bit-rate using clamp(), and bit-rate is the
case of negative value, it enables the calculation of the error bit.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:14:44 -07:00
Nobuhiro Iwamatsu
b7d66397f4 serial: sh-sci: Updated calculation of bit error rate and bit rate
Currently, the decimal point is discarded calculation of BRR.
Therefore, it can not calculate a value close to the correct value.
This patch fixes this problem by using DIV_ROUND_CLOSEST.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:14:44 -07:00
Greg Kroah-Hartman
ca17749259 Merge 3.16-rc5 into tty-next.
We want those fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-13 15:52:12 -07:00
Rasmus Villemoes
07584d4a35 drivers: tty: Fix use-after-free in pty_common_install
In 2c964a2f "drivers: tty: Merge alloc_tty_struct and
initialize_tty_struct", I messed up the refactorization of
pty_common_install, causing use-after-free and NULL pointer derefs on
various error paths. This should fix it.

Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-12 17:21:47 -07:00
Rasmus Villemoes
2c964a2f41 drivers: tty: Merge alloc_tty_struct and initialize_tty_struct
The two functions alloc_tty_struct and initialize_tty_struct are
always called together. Merge them into alloc_tty_struct, updating its
prototype and the only two callers of these functions.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-11 17:54:28 -07:00
Geert Uytterhoeven
493671a2ce serial: pch_uart: Update error message for dmaengine_prep_slave_sg() API
Commit 16052827d9 ("dmaengine/dma_slave:
introduce inline wrappers") changed the code to use the new API, but forgot
to update an error message.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Jiri Kosina <trivial@kernel.org>
Cc: linux-serial@vger.kernel.org
--
v2:
  - New
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-11 17:49:46 -07:00
Vineet Gupta
f363ca2fc8 serial/arc: Fix warning with CONSOLE_POLL
| drivers/tty/serial/arc_uart.c:516:2: warning: (near initialization for 'arc_serial_pops.poll_put_char') [enabled by default]

This partially undoes "serial/arc: use uart_console_write() helper" by
restoring the prototpye of poll helper and use a different one in
uart_console_write()

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-11 17:49:46 -07:00
Daniel Thompson
2970b7f5ea serial: altera: Adopt uart_console_write()
This driver does not currently use uart_console_write() and instead
provides is own LF to LFCR conversion in it's console_write() method.
We should use the library function instead.

Cmopile tested only (with ARCH=arm).

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-11 17:49:46 -07:00
Uwe Kleine-König
d36f47fa84 serial: efm32: correct namespacing of location property
Olof Johansson pointed out that usually the company name is picked as
namespace prefix to specific properties. So expect "energymicro,location"
but fall back to the previously introduced name "efm32,location".

Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-11 17:49:46 -07:00
Peter Hurley
8bec751bd6 serial: imx: Fix build breakage
Fix breakage introduced by
commit c557d392fb,
'serial: Test for no tx data on tx restart'.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-11 17:43:13 -07:00
Peter Hurley
99ecb001f5 serial: arc_uart: Use uart_circ_empty() for open-coded comparison
Replace open-coded test for empty tx ring buffer with equivalent
helper function, uart_circ_empty(). No functional change.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:31:34 -07:00
Peter Hurley
c557d392fb serial: Test for no tx data on tx restart
Commit 717f3bbab3,
'serial_core: Fix conditional start_tx on ring buffer not empty'
exposes an incorrect assumption in several drivers' start_tx methods;
the tx ring buffer can, in fact, be empty when restarting tx while
performing flow control.

Affected drivers:
sunsab.c
ip22zilog.c
pmac_zilog.c
sunzilog.c
m32r_sio.c
imx.c

Other in-tree serial drivers either are not affected or already
test for empty tx ring buffer before transmitting.

Test for empty tx ring buffer in start_tx() method, after transmitting
x_char (if applicable).

Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Seth Bollinger <sethb@digi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Cc: stable <stable@vger.kernel.org> # 3.15
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:31:34 -07:00
Stephen Boyd
68252424a7 tty: serial: msm: Support big-endian CPUs
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: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:10:42 -07:00
Dan Carpenter
db3a1a43fb serial: txx9: remove duplicate TXX9_SIFCR_TDIL_MASK define
The TXX9_SIFCR_TDIL_MASK define is cut and pasted twice so we can delete
the second instance.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:10:42 -07:00
Peter Hurley
8bd67d7d2c serial: blackfin: Fix CTS flow control
blackfin uart port drivers mistakenly set the struct uart_port
flags bit UPF_BUG_THRE (which only has meaning to the 8250 core)
while trying to set ASYNC_CTS_FLOW.

Uart port drivers can override termios settings based on actual
hardware support in their .set_termios method; the serial core
sets the appropriate port flags based on the overrides.
Overriding only the initial termios settings is accomplished
by only perform those overrides if the old termios parameter is
NULL.

CC: Sonic Zhang <sonic.zhang@analog.com>
CC: adi-buildroot-devel@lists.sourceforge.net
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:07:46 -07:00
Peter Hurley
c18b55fd17 tty: serial: Fix termios/port flags mismatch
Uart port drivers may reconfigure termios settings based on available
hardware support; set/clear ASYNC_CTS_FLOW and ASYNC_CHECK_CD _after_
calling the port driver's .set_termios method.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:07:46 -07:00
Peter Hurley
7c6d340f4f tty: Call hangup method in modern style
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:07:46 -07:00
Peter Hurley
e359a4e38d tty: Remove tty_hung_up_p() tests from tty drivers' open()
Since at least before 2.6.30, it has not been possible to observe
a hung up file pointer in a tty driver's open() method unless/until
the driver open() releases the tty_lock() (eg., before blocking).

This is because tty_open() adds the file pointer while holding
the tty_lock() _and_ doesn't release the lock until after calling
the tty driver's open() method. [ Before tty_lock(), this was
lock_kernel(). ]

Since __tty_hangup() first waits on the tty_lock() before
enumerating and hanging up the open file pointers, either
__tty_hangup() will wait for the tty_lock() or tty_open() will
not yet have added the file pointer. For example,

CPU 0                          |  CPU 1
                               |
tty_open                       |  __tty_hangup
  ..                           |    ..
  tty_lock                     |    ..
  tty_reopen                   |    tty_lock  / blocks
  ..                           |
  tty_add_file(tty, filp)      |
  ..                           |
  tty->ops->open(tty, filp)    |
    tty_port_open              |
      tty_port_block_til_ready |
        ..                     |
        while (1)              |
          ..                   |
          tty_unlock           |    / unblocks
          schedule             |    for each filp on tty->tty_files
                               |      f_ops = tty_hung_up_fops;
                               |    ..
                               |    tty_unlock
          tty_lock             |
  ..                           |
  tty_unlock                   |

Note that since tty_port_block_til_ready() and similar drop
the tty_lock while blocking, when woken, the file pointer
must then be tested for having been hung up.

Also, fix bit-rotted drivers that used extra_count to track the
port->count bump.

CC: Mikael Starvik <starvik@axis.com>
CC: Samuel Ortiz <samuel@sortiz.org>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:06:49 -07:00
Peter Hurley
5fda7a0e71 serial: Use UPF_* constants with struct uart_port flags
Fix ASYNC_* constant usage that should be the corresponding UPF_*
constant.

CC: Grant Likely <grant.likely@linaro.org>
CC: Rob Herring <robh+dt@kernel.org>
CC: devicetree@vger.kernel.org
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:06:49 -07:00
Peter Hurley
01261cb943 tty: ipwireless: Remove tty->closing abort from ipw_open()
tty->closing cannot be set on ipw_open() because the ipwireless tty
driver does not call any functions that set tty->closing.

CC: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:06:49 -07:00
Peter Hurley
ddc7b758a6 tty: Move tty->closing from port lock critical section
tty->closing informs the line discipline that the hardware will
be shutting down imminently, and to disable further input other
than soft flow control (but to still allow additional output).

However, the tty lock is the necessary lock for preventing
concurrent changes to tty->closing. As shown by the call-tree
audit [1] of functions that modify tty->closing, the tty lock
is already held for those functions.

[1]
Call-tree audit of functions that modify tty->closing
* does not include call tree to tty_port_close(), tty_port_close_start(),
  or tty_port_close_end() which is already documented in
  'tty: Document locking for tty_port_close{,start,end}' that shows
  callers to those 3 functions hold the tty lock

tty_release()
  tty->ops->close() --+
                      |
__tty_hangup()        |
  tty->ops->close() --+
                      |
        mp_close():drivers/staging/sb105x/sb_pci_mp.c
        dngc_tty_close():drivers/staging/dgnc/dgnc_tty.c
        dgap_tty_close():drivers/staging/dgap/dgap_tty.c
        dgrp_tty_close():drivers/staging/dgrp/dgrp_tty.c
        rp_close():drivers/tty/rocket.c
        hvsi_close():drivers/tty/hvc/hvsi.c
        rs_close():drivers/tty/serial/68328serial.c
        rs_close():drivers/tty/serial/crisv10.c
        uart_close():drivers/tty/serial/serial_core.c
        isdn_tty_close():drivers/isdn/i4l/isdn_tty.c
        tty3215_close():drivers/s390/char/con3215.c

tty_open()
  tty_ldisc_setup() ----+
                        |
__tty_hangup()          |
  tty_ldisc_hangup() ---+
                        |
tty_set_ldisc() --------+
  tty_ldisc_restore() --+
                        |
                        +- tty_ldisc_open()
                             ld->ops->open() --+
                                               |
                                               +- n_tty_open()

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:06:48 -07:00
Peter Hurley
9c9928bded tty: Document locking for tty_port_hangup()
The tty lock is held when the tty driver's hangup() method is called
(from the lone call-site, __tty_hangup()). The call-tree audit [1]
of tty_port_hangup() is a closed graph of the callers of
tty_port_hangup(); ie., all callers originate only from __tty_hangup().

Of these callers, none drop the tty lock prior to calling
tty_port_hangup().

[1]
Call-tree audit of tty_port_hangup()

__tty_hangup()
  tty->ops->hangup() --+
                       |
        rs_hangup():arch/ia64/hp/sim/simserial.c
        line_hangup():arch/um/drivers/line.c
        gdm_tty_hangup():drivers/staging/gdm724x/gdm_tty.c
        fwtty_hangup():drivers/staging/fwserial/fwserial.c
        acm_tty_hangup():drivers/usb/class/cdc-acm.c
        serial_hangup():drivers/usb/serial/usb-serial.c
        ipoctal_hangup():drivers/ipack/devices/ipoctal.c
        cy_hangup():drivers/tty/cyclades.c
        isicom_hangup():drivers/tty/isicom.c
        rp_hangup():drivers/tty/rocket.c
        dashtty_hangup():drivers/tty/metag_da.c
        moxa_hangup():drivers/tty/moxa.c
        gsmtty_hangup():drivers/tty/n_gsm.c
        goldfish_tty_hangup():drivers/tty/goldfish.c
        ehv_bc_tty_hangup():drivers/tty/ehv_bytechan.c
        mxser_hangup():drivers/tty/mxser.c
        kgdb_nmi_tty_hangup():drivers/tty/serial/kgdb_nmi.c
        ifx_spi_hangup():drivers/tty/serial/ifx6x60.c
        ntty_hangup():drivers/tty/nozomi.c
        capinc_tty_hangup():drivers/isdn/capi/capi.c
        mgslpc_hangup():drivers/char/pcmcia/synclink_cs.c
        sdio_uart_hangup():drivers/mmc/card/sdio_uart.c
        rfcomm_tty_hangup():net/bluetooth/rfcomm/tty.c
                       |
                       +- tty_port_hangup()

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:05:19 -07:00
Peter Hurley
c590f6b6cf tty: Document locking for tty_port_block_til_ready()
The tty lock is held when the tty driver's open() method is called
(from tty_open()). The call-tree audit [1] of tty_port_block_til_ready()
is a closed graph of the callers of tty_port_block_til_ready();
ie., all callers originate only from tty_open().

Of these callers, none drop the tty lock.

Also, document tty_port_block_til_ready() may drop and reacquire
the tty lock when blocking, which means the tty or tty_port may have
changed state.

[1]
Call-tree audit of tty_port_block_til_ready()
* does not include call tree of tty_port_open() which is already
  documented in 'tty: Document locking from tty_port_open()'

tty_open()
  tty->ops->open() --+
                     |
        cy_open():drivers/tty/cyclades.c
        rp_open():drivers/tty/rocket.c
        rs_open():drivers/tty/amiserial.c
        moxa_open():drivers/tty/moxa.c
        gsmtty_open():drivers/tty/n_gsm.c
        rs_open():drivers/tty/serial/68328serial.c
        uart_open():drivers/tty/serial/serial_core.c
        isdn_tty_open():drivers/isdn/i4l/isdn_tty.c
        mgslpc_open():drivers/char/pcmcia/synclink_cs.c
                     |
                     +- tty_port_block_til_ready()

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:05:19 -07:00
Peter Hurley
addd4672bb tty: Document locking for tty_port_open()
The tty lock is held when the tty driver's open method is called
(from the lone call-site, tty_open()). The call-tree audit [1] of
tty_port_open() is a closed graph of the callers of tty_port_open();
ie., all callers originate from only tty_open().

Of these callers, none drop the tty lock.

Also, document that tty_port_block_til_ready() may drop and reacquire
the tty lock when blocking, which means the tty or tty_port may have
changed state.

[1]
Call-tree audit of tty_port_open()

tty_open()
  tty->ops->open() --+
                     |
        rs_open():arch/ia64/hp/sim/simserial.c
       *line_open():arch/um/drivers/line.c
        gdm_tty_open():drivers/staging/gdm724x/gdm_tty.c
        fwtty_open():drivers/staging/fwserial/fwserial.c
        acm_tty_open():drivers/usb/class/cdc-acm.c
        serial_open():drivers/usb/serial/usb-serial.c
        pti_tty_driver_open():drivers/misc/pti.c
        ipoctal_open():drivers/ipack/devices/ipoctal.c
        isicom_open():drivers/tty/isicom.c
        dashtty_open():drivers/tty/metag_da.c
        goldfish_tty_open():drivers/tty/goldfish.c
        ehv_bc_tty_open():drivers/tty/ehv_bytechan.c
        mxser_open():drivers/tty/mxser.c
        kgdb_nmi_tty_open():drivers/tty/serial/kgdb_nmi.c
        ifx_spi_open():drivers/tty/serial/ifx6x60.c
        smd_tty_open():drivers/tty/serial/msm_smd_tty.c
        ntty_open():drivers/tty/nozomi.c
        capinc_tty_open():drivers/isdn/capi/capi.c
        tpk_open():drivers/char/ttyprintk.c
        sdio_uart_open():drivers/mmc/card/sdio_uart.c
        rfcomm_tty_open():net/bluetooth/rfcomm/tty.c
                     |
                     +- tty_port_open()

* line_open() is the .open method for 2 um drivers
  declared in ./arch/um/drivers/stdio_console.c and
  in ./arch/um/drivers/ssl.c, and not called directly

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:05:19 -07:00
Peter Hurley
0733db91d0 tty: Document locking for tty_port_close{,start,end}()
The tty lock is held when the tty driver's .close method is called
(from the two lone call-sites of tty_release() and __tty_hangup()).
The call-tree audit[1] of tty_port_close(), tty_port_close_start,
and tty_port_close_end() is a closed graph of the callers of these
3 functions; ie., all callers originate from only tty_release()
or __tty_hangup().

Of these callers, none drop the tty lock.

Also, document tty_port_close_start() may drop and reacquire the
tty lock in tty_wait_until_sent_from_close(), which means the tty
or tty_port may have changed state (but not reopened or hung up).

[1]
Call-tree audit of tty_port_close, tty_port_close_start, and tty_port_close_end()

tty_release()
  tty->ops->close() --+
                      |
__tty_hangup()        |
  tty->ops->close() --+
                      |
                      +- rp_close():drivers/tty/rocket.c -------------------+
                      +- uart_close():drivers/tty/serial/serial_core.c -----+
                      |                                                     +- tty_port_close_start()
                      |
                      |
                      +- close():drivers/tty/synclinkmp.c ------------------+
                      +- rs_close():drivers/tty/amiserial.c ----------------+
                      +- gsmtty_close():drivers/tty/n_gsm.c ----------------+
                      +- mxser_close():drivers/tty/mxser.c -----------------+
                      +- close():drivers/tty/synclink_gt.c -----------------+
                      +- mgsl_close():drivers/tty/synclink.c ---------------+
                      +- isdn_tty_close():drivers/isdn/i4l/isdn_tty.c ------+
                      +- mgslpc_close():drivers/char/pcmcia/synclink_cs.c --+
                      +- ircomm_tty_close():net/irda/ircomm/ircomm_tty.c ---+
                      |                                                     |
        rs_close():arch/ia64/hp/sim/simserial.c                             |
       *line_close():arch/um/drivers/line.c                                 |
        gdm_tty_close():drivers/staging/gdm724x/gdm_tty.c
        fwtty_close():drivers/staging/fwserial/fwserial.c
        acm_tty_close():drivers/usb/class/cdc-acm.c
        serial_close():drivers/usb/serial/usb-serial.c
        pti_tty_driver_close():drivers/misc/pti.c
        ipoctal_close():drivers/ipack/devices/ipoctal.c
        cy_close():drivers/tty/cyclades.c
        isicom_close():drivers/tty/isicom.c
        dashtty_close():drivers/tty/metag_da.c
        moxa_close():drivers/tty/moxa.c
        goldfish_tty_close():drivers/tty/goldfish.c
        ehv_bc_tty_close():drivers/tty/ehv_bytechan.c
        kgdb_nmi_tty_close():drivers/tty/serial/kgdb_nmi.c
        ifx_spi_close():drivers/tty/serial/ifx6x60.c
        smd_tty_close():drivers/tty/serial/msm_smd_tty.c
        ntty_close():drivers/tty/nozomi.c
        capinc_tty_close():drivers/isdn/capi/capi.c
        tpk_close():drivers/char/ttyprintk.c
        sdio_uart_close():drivers/mmc/card/sdio_uart.c                      |
        rfcomm_tty_close():net/bluetooth/rfcomm/tty.c                       |
                      |                                                     |
                      +- tty_port_close():drivers/tty/tty_port.c -----------+
                                                                            |
                                                                            +- tty_port_close_start()
                                                                            +- tty_port_close_end()

* line_close() is the .close method for 2 um drivers,
  declared in ./arch/um/drivers/stdio_console.c and
  in ./arch/um/drivers/ssl.c, and not called directly

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:05:19 -07:00
Stefan Agner
ed9891bf09 serial: fsl_lpuart: calculate DMA burst
The DMA burst size must match the transmit FIFO depth in order
to make sure all character are transmitted. This patch calculates
DMA burst size by using FIFO depth rather than use the hardcoded
16 bytes. This is required since some UARTs (e.g. UART2 on Vybrid)
have a FIFO depth of 8 bytes.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:03:59 -07:00
Stefan Agner
90abef91c5 serial: fsl_lpuart: move DMA RX timeout calculation
The DMA RX timeout calculation is done based on FIFO buffer size and
port timeout when setting up DMA. However, both variables are not
necessarily initialized at DMA initialization time, which can lead
to a division by zero.

Move the timeout calculation to set_termios where both variables
are initialized.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:03:59 -07:00
Peter Hurley
ae84db9661 serial: core: Preserve termios c_cflag for console resume
When a tty is opened for the serial console, the termios c_cflag
settings are inherited from the console line settings.
However, if the tty is subsequently closed, the termios settings
are lost. This results in a garbled console if the console is later
suspended and resumed.

Preserve the termios c_cflag for the serial console when the tty
is shutdown; this reflects the most recent line settings.

Fixes: Bugzilla #69751, 'serial console does not wake from S3'
Reported-by: Valerio Vanni <valerio.vanni@inwind.it>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:55:32 -07:00
Pradeep Goudagunta
b31245b942 serial: tegra: ack the rx dma desc after transfer terminated
The Rx dma descriptor allocated without the DMA_ACK flags so that
once after tarnsfer done or terminated, client can ack the descriptor
to free it for later use.

If the Rx DMA is terminated for some reason then rx-dma descriptor
is not getting acked which causes the memory leak and list of usage
desc to grow continuously.

Hence, acknowledge the rx-dma descriptor once transfer is terminated
to avoid memory leak and desc list to grow.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:53:20 -07:00
Pradeep Goudagunta
5e3dbfca3b serial: tegra: update tx_circular buffer only when TX_DMA is in progress
When channel is require to stop transmit then update the Tx circular
buffer only when DMA based transfer is in progress. If there is no
DMA based transfer then no need to update the Tx buffer.

Signed-off-by: Pradeep Goudagunta <pgoudagunta@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:53:20 -07:00
Arnd Bergmann
080029b149 serial: lpc32xx uart module can't do console
Every uart driver that provides a console driver needs to
be built-in for the console code to work, we get a build
error for modular console drivers.

This changes the SERIAL_HS_LPC32XX_CONSOLE symbol to depend
on the SERIAL_HS_LPC32XX driver being built-in, just like
we do for all the other uart drivers.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:48:56 -07:00
Arnd Bergmann
2ee881b74e serial: pxa: fix build with !SERIAL_PXA_CONSOLE
When CONFIG_SERIAL_PXA_CONSOLE is disabled, the serial_pxa_get_poll_char
and serial_pxa_put_poll_char functions are not defined, and we can't
reference them.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:48:41 -07:00
Vineet Gupta
8c6abf7a9e serial/arc: Enable DT based earlycon
This allows a param less earlycon to pick up the earlyconsole from
chosen/stdout-path

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:45:30 -07:00
Vineet Gupta
8dbe1d5e09 serial/arc: inline the probe helper
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:45:30 -07:00
Vineet Gupta
91f1b62a9b serial/arc: remove last remanants of platform data
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:45:29 -07:00
Vineet Gupta
2e6fb7cbd0 serial/arc: remove earlyprintk support and switch to earlycon
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:43:27 -07:00
Vineet Gupta
27cfe4ec17 serial/arc: Use generic earlycon infrastructure
With this change both earlyprintk and earlycon coexist
We switch over to latter in next patch

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:43:27 -07:00
Vineet Gupta
5a56d59e85 serial/arc: Remove the workaround for legacy ISS
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:43:27 -07:00
Vineet Gupta
12d15e6f63 serial/arc: Refactor by referencing to uart_port where possible
The ARC UART MMIO helpers would take arc_uart_port and then reference
generic uart_port->membase member. So change them to difrectly refer to
uart_port and fix call sites accordingly.

This removes the need for to_arc_port() converion almost eveeywhere and
makes code a bit easier to read.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:43:27 -07:00