linux-toradex.git/drivers/serial/8250.c, branch tegra-10.11.0

U6715 16550A serial driver support

2010-08-10T20:47:46+00:00

UART Features extract from STEricsson U6715 data-sheet (arm926 SoC for mobile phone):
* Fully compatible with industry standard 16C550 and 16C450 from various
manufacturers
* RX and TX 64 byte FIFO reduces CPU interrupts
* Full double buffering
* Modem control signals include CTS, RTS, (and DSR, DTR on UART1 only)
* Automatic baud rate selection
* Manual or automatic RTS/CTS smart hardware flow control
* Programmable serial characteristics:
– Baud rate generation (50 to 3.25M baud)
– 5, 6, 7 or 8-bit characters
– Even, odd or no-parity bit generation and detection
– 1, 1.5 or 2 stop bit generation
* Independent control of transmit, receive, line status, data set interrupts and FIFOs
* Full status-reporting capabilities
* Separate DMA signaling for RX and TX
* Timed interrupt to spread receive interrupt on known duration
* DMA time-out interrupt to allow detection of end of reception
* Carkit pulse coding and decoding compliant with USB carkit control interface [40]

In 16550A auto-configuration, if the fifo size is 64 then it's an U6 16550A port
Add set_termios hook & export serial8250_do_set_termios to change uart
clock following baudrate

Signed-off-by: Philippe Langlais 
Acked-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

8250: fix set_ldisc operation

2010-08-10T20:47:44+00:00

The ldisc number now gets passed into ->set_ldisc.

Signed-off-by: Arnd Bergmann 
Cc: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

serial: add UART_CAP_EFR and UART_CAP_SLEEP flags to 16C950 UARTs definition

2010-08-10T20:47:38+00:00

Adding UART_CAP_EFR and UART_CAP_SLEEP flags will enable sleep mode
and automatic CTS flow control for 16C950 UARTs. It will also avoid
capabilities detection warning like this:

"ttyS0: detected caps 00000700 should be 00000100"

Signed-off-by: Yegor Yefremov 
Signed-off-by: Greg Kroah-Hartman

SERIAL: 8250: Remove SERIAL_8250_AU1X00

2010-08-05T12:26:07+00:00

Remove the SERIAL_8250_AU1X00 config symbol.  Instead, use the MIPS_ALCHEMY
one which is always defined when building an Au1x00-based platform.

Signed-off-by: Manuel Lauss 
To: Linux-MIPS 
Cc: Linux-serial 
Patchwork: https://patchwork.linux-mips.org/patch/1461/
Signed-off-by: Ralf Baechle 

This one depends on a previous patch (which removes SOC_AU1X00 and changes
MACH_ALCHEMY) to apply cleanly (and then actually work), so I'd love for
this to go in via the mips tree.

kgdb,8250,pl011: Return immediately from console poll

2010-05-21T02:04:22+00:00

The design of the kdb shell requires that every device that can
provide input to kdb have a polling routine that exits immediately if
there is no character available.  This is required in order to get the
page scrolling mechanism working.

Changing the kernel debugger I/O API to require all polling character
routines to exit immediately if there is no data allows the kernel
debugger to process multiple input channels.

NO_POLL_CHAR will be the return code to the polling routine when ever
there is no character available.

CC: linux-serial@vger.kernel.org
Signed-off-by: Jason Wessel

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32+00:00

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo 
Guess-its-ok-by: Christoph Lameter 
Cc: Ingo Molnar 
Cc: Lee Schermerhorn

serial 8250: enable PPS support

2010-03-12T23:52:43+00:00

Automagically function serial8250_enable_ms() is called when PPS ldisc
is selected.

Signed-off-by: Rodolfo Giometti 
Cc: David Woodhouse 
Cc: Greg KH 
Cc: Alan Cox 
Cc: Alexander Gordeev 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

serial: copy UART properties of UPF_FIXED_TYPE ports provisioned using early_serial_setup

2010-03-02T22:43:07+00:00

Augment the UPF_FIXED_TYPE logic, which currently applies to UART ports
provisioned using platform_device_register.

The suggested patch applies same logic into 'serial8250_register_ports',
making UART ports provisioned using early_serial_setup inherit their
properties from the uart_config entry.

Signed-off-by: Shmulik Ladkani 
Cc: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

SERIAL 8250: Fixes for Alchemy UARTs.

2010-02-27T11:52:57+00:00

Limit the amount of address space claimed for Alchemy serial ports to
0x1000.  On the Au1300, ports are only 0x1000 apart, and the registers
only extend to 0x110 at most on all supported alchemy models.

On the Au1300 the autodetect logic no longer works and this makes it
necessary to specify the port type through platform data.  Because of
this the MSR quirk needs to be moved outside the autoconfig() function
which will no longer be called when UPF_FIXED_TYPE is specified.

Signed-off-by: Manuel Lauss 
Cc: Andrew Morton ,
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle

serial: 8250: add serial transmitter fully empty test

2010-02-16T23:55:51+00:00

When controlling an industrial radio modem it can be necessary to
manipulate the handshake lines in order to control the radio modem's
transmitter, from userspace.

The transmitter should not be turned off before all characters have been
transmitted.  serial8250_tx_empty() was reporting that all characters were
transmitted before they actually were.

===

Discovered in parallel with more testing and analysis by Kees Schoenmakers
as follows:

I ran into an NetMos 9835 serial pci board which behaves a little
different than the standard.  This type of expansion board is very common.

"Standard" 8250 compatible devices clear the 'UART_LST_TEMT" bit together
with the "UART_LSR_THRE" bit when writing data to the device.

The NetMos device does it slightly different

I believe that the TEMT bit is coupled to the shift register.  The problem
is that after writing data to the device and very quickly after that one
does call serial8250_tx_empty, it returns the wrong information.

My patch makes the test more robust (and solves the problem) and it does
not affect the already correct devices.

Alan:

  We may yet need to quirk this but now we know which chips we have a
  way to do that should we find this breaks some other 8250 clone with
  dodgy THRE.

Signed-off-by: Dick Hollenbeck 
Signed-off-by: Alan Cox 
Cc: Kees Schoenmakers 
Signed-off-by: Andrew Morton 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman