Commit Graph

53 Commits

Author SHA1 Message Date
Anatolij Gustschin
6acc683351 serial: mpc52xx_uart: re-enable mpc5121 PSC UART support
Currently the support for MPC5121 PSC UART in the mpc52xx_uart
driver is broken (only console pre-initialized by the bootloader
works). Re-enable it now by providing MPC5121 specific ops
for PSCx clock activation, FIFO controller init/uninit and
MPC5121 PSC FIFO shared interrupt handling functions.

Signed-off-by: John Rigby <jcrigby@gmail.com>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-02-16 22:30:03 -07:00
Julia Lawall
b7a8212cae drivers/serial/mpc52xx_uart.c: Use UPIO_MEM rather than SERIAL_IO_MEM
As in the commit 9b4a161777, use UPIO_MEM
rather than SERIAL_IO_MEM.  Both have the same value.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@has_sc@
@@

#include <linux/serial_core.h>

@depends on has_sc@
@@

- SERIAL_IO_MEM
+ UPIO_MEM
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2009-10-15 09:58:28 -06:00
Alan Cox
ebd2c8f6d2 serial: kill off uart_info
We moved this into uart_state, now move the fields out of the separate
structure and kill it off.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:28 -07:00
Wolfgang Denk
87c441e54d powerpc/5xxx: Add common mpc5xxx_get_bus_frequency() function
So far, MPC512x used mpc512x_find_ips_freq() to get the bus frequency,
while MPC52xx used mpc52xx_find_ipb_freq().  Despite the different
clock names (IPS vs. IPB) the code was identical.

Use common code for both processor families.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2009-06-17 00:30:22 -06:00
Roel Kluin
b898f4f869 drivers/serial/mpc52xx_uart.c: fix array overindexing check
The check for an overindexing of mpc52xx_uart_{ports,nodes} has an
off-by-one.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-29 08:40:02 -07:00
Grant Likely
d9f0c5f9bc powerpc/5200: Don't specify IRQF_SHARED in PSC UART driver
The MPC5200 PSC device is wired up to a dedicated interrupt line
which is never shared.  This patch removes the IRQF_SHARED flag
from the request_irq() call which eliminates the "IRQF_DISABLED
is not guaranteed on shared IRQs" warning message from the console
output.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
2009-02-04 11:23:56 -07:00
Grant Likely
3b5ebf8e1a powerpc/5200: Stop using device_type and port-number properties
There is no reason for the PSC UART driver or the Ethernet driver
to require a device_type property.  The compatible value is sufficient
to uniquely identify the device.  Remove it from the driver.

The whole 'port-number' scheme for assigning numbers to PSC uarts was
always rather half baked and just adds complexity.  Remove it from the
driver.  After this patch is applied, PSC UART numbers are simply
assigned from the order they are found in the device tree (just like
all the other devices).  Userspace can query sysfs to determine what
ttyPSC number is assigned to each PSC instance.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
2009-02-03 12:30:25 -07:00
Wolfram Sang
418441d9eb powerpc/mpc5200: fix error paths in PSC UART probe function
- error cases for mapbase and irq were unbundled
- mapped irq now gets disposed on error

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-12-21 02:54:32 -07:00
Wolfram Sang
aec739e010 powerpc/mpc5200: add rts/cts handling in PSC UART driver
Add RTS/CTS-support for the PSC of the MPC5200B. Tested with a Phytec
MPC5200B-IO.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-12-21 02:54:32 -07:00
René Bürgel
b65149880d powerpc/mpc5200: Make PSC UART driver update serial errors counters
This patch adds the capability to the mpc52xx-uart to report framing
errors, parity errors, breaks and overruns to userspace. These values
may be requested in userspace by using the ioctl TIOCGICOUNT.

Signed-off-by: René Bürgel <r.buergel@unicontrol.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-12-21 02:54:31 -07:00
Nick Andrew
c4f0124057 Fix incorrect use of loose in tty/serial drivers
[Folded together as one diff from 3]

It should be 'lose', not 'loose'.

Signed-off-by: Nick Andrew <nick@nick-andrew.net>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-05 13:40:52 -08:00
Kumar Gala
8d1fb8cbaa serial/mpc52xx_uart: remove code associated with !CONFIG_PPC_MERGE
Now that arch/ppc is gone we don't need CONFIG_PPC_MERGE anymore
remove the dead code associated with !CONFIG_PPC_MERGE.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-09-25 10:28:26 -05:00
Takashi Iwai
a88487c79b Fix compile errors in SGI console drivers (linux-next tree)
The below is the patch to replace blindly all possible places,
including Jack's fixes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
(Reviewed and checked rather than blindly added)
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-20 17:12:36 -07:00
Andrew Liu
fbe543b412 Fix a potential issue in mpc52xx uart driver
mpc52xx_uart_int and __uart_put_char both try to acquire the
port->lock. Therefore the function sequence of:

mpc52xx_uart_int--> ...-->flush_to_ldisc-->...-->__uart_put_char

can potentially trigger a deadlock. To avoid this deadlock a fix
similar to that found in the 8250.c serial driver is applied. The
deadlock is avoided by releasing the lock before pushing a buffer
and reacquiring it when completed.

Signed-off-by: Andrew Liu <shengping.liu@windriver.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-05-01 11:59:12 -06:00
Grant Likely
bc775eac63 [POWERPC] mpc5200: Fix unterminated of_device_id table
If CONFIG_PPC_MPC5121 is not set, then the of_device_id table for the
mpc5200 serial driver will not get terminated with a NULL entry.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-04-29 07:16:18 -06:00
Kay Sievers
e169c13964 serial: fix platform driver hotplug/coldplug
Since 43cc71eed1, the platform modalias is
prefixed with "platform:".  Add MODULE_ALIAS() to the hotpluggable serial
platform drivers, to re-enable auto loading.

NOTE that Kconfig for some of these drivers doesn't allow modular builds, and
thus doesn't match the driver source's unload support.  Presumably their
unload code is buggy and/or weakly tested...

[dbrownell@users.sourceforge.net: more drivers, registration fixes]
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-15 19:35:40 -07:00
Grant Likely
52b804829c [POWERPC] mpc52xx: fix compile error introduce when rebasing patch
When rebasing one of the mpc5200 psc UART patches I made a mistake and
damaged the patch.

This patch fixes the compile failure introduced in commit
25ae3a0739

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-02-06 22:29:25 -07:00
John Rigby
25ae3a0739 [POWERPC] mpc512x: Add MPC512x PSC support to MPC52xx psc driver
Add 512x support using the psc_ops framework established
with the previous patch.

All 512x PSCs share the same interrupt so add
IRQF_SHARED to irq flags.

Signed-off-by: John Rigby <jrigby@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-02-06 14:05:40 -07:00
John Rigby
599f030cc5 [POWERPC] mpc512x: Factor out 5200 dependencies from 52xx psc driver
PSC devices are different between the mpc5200 and the mpc5121
this patch localizes the differences in preparation for adding mpc5121
support to the psc uart driver.

Signed-off-by: John Rigby <jrigby@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-02-06 14:05:32 -07:00
Grant Likely
66ffbe490b [POWERPC] mpc5200: normalize compatible property bindings
Update MPC5200 drivers to also look for compatible properties in the
form "fsl,mpc5200-*" to better conform to open firmware generic names
recommended practice as published here:

http://www.openfirmware.org/1275/practice/gnames/gnamv14a.html

This patch should *not* break compatibility with older device trees
which do not use the 'fsl,' prefix.  The drivers will still bind against
the older names also.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-01-26 15:26:01 -07:00
John Rigby
406b7d4f7b [POWERPC] mpc5200: Cleanup checkpatch.pl problems in mpc52xx_uart.c
In preparation of adding MPC5121 support
cleanup some things that checkpatch.pl complains
about also some minor fixes suggested by
Stephen Rothwell.

Signed-off-by: John Rigby <jrigby@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-01-21 11:01:33 -07:00
John Rigby
94f389485e [POWERPC] Separate MPC52xx PSC FIFO registers from rest of PSC
This is in preparation for the addition of MPC512x
PSC support.  The main difference in the 512x is
in the fifo registers.

Signed-off-by: John Rigby <jrigby@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-01-21 11:01:32 -07:00
Grant Likely
283029d16a [POWERPC] Add of_find_matching_node() helper function
Similar to of_find_compatible_node(), of_find_matching_node() and
for_each_matching_node() allow you to iterate over the device tree
looking for specific nodes, except that they take of_device_id
tables instead of strings.

This also moves of_match_node() from driver/of/device.c to
driver/of/base.c to colocate it with the of_find_matching_node which
depends on it.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-17 14:53:22 +11:00
Grant Likely
5dd80d5d09 mpc52xx-uart: fix compile warning (format type mismatch)
Trivial compile warning fix

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-14 08:57:30 -07:00
John Rigby
af6a9aabc1 [POWERPC] 52xx: Fix mpc52xx_uart_of_assign to use correct index
Use idx as index into mpc52xx_uart_nodes instead of i

Signed-off-by: John Rigby <jrigby@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-09-14 08:54:05 -05:00
Grant Likely
a348119778 [POWERPC] Don't shutdown TX on mpc5200 serial port if it is a console
If the serial port gets shut down, then console output stalls.  9 out
of 10 kernel hackers agree, this is a bad thing.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-05-07 20:31:15 +10:00
Stephen Rothwell
40cd3a4564 [POWERPC] Rename get_property to of_get_property: drivers
These are all the remaining instances of get_property.  Simple rename of
get_property to of_get_property.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-05-02 20:04:32 +10:00
Sylvain Munaut
fc7900bb04 [POWERPC] Dispose irq mapping when done in mpc52xx_serial.c
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-02-17 18:20:18 +11:00
Grant Likely
e3aba81d15 [POWERPC] Fixup mp5200 drivers to match device tree changes
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-02-13 15:35:53 +11:00
Grant Likely
c98750c2eb [POWERPC] Fix mpc52xx serial driver to work for arch/ppc again
The mpc52xx_uart_of_enumerate() function was added when adding 52xx
support to arch/powerpc, but it must not be called for arch/ppc.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-01-09 17:03:02 +11:00
Alan Cox
606d099cdd [PATCH] tty: switch to ktermios
This is the grungy swap all the occurrences in the right places patch that
goes with the updates.  At this point we have the same functionality as
before (except that sgttyb() returns speeds not zero) and are ready to
begin turning new stuff on providing nobody reports lots of bugs

If you are a tty driver author converting an out of tree driver the only
impact should be termios->ktermios name changes for the speed/property
setting functions from your upper layers.

If you are implementing your own TCGETS function before then your driver
was broken already and its about to get a whole lot more painful for you so
please fix it 8)

Also fill in c_ispeed/ospeed on init for most devices, although the current
code will do this for you anyway but I'd like eventually to lose that extra
paranoia

[akpm@osdl.org: bluetooth fix]
[mp3@de.ibm.com: sclp fix]
[mp3@de.ibm.com: warning fix for tty3270]
[hugh@veritas.com: fix tty_ioctl powerpc build]
[jdike@addtoit.com: uml: fix ->set_termios declaration]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:57 -08:00
Grant Likely
b9272dfdfe [POWERPC] Add of_platform_bus support to mpc52xx psc uart driver
Needed to support mpc52xx boards in arch/powerpc.  This patch
retains the platform_bus support when compiling for arch/ppc,
but uses the of_platform bindings for arch/powerpc.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-12-05 09:53:07 +11:00
Grant Likely
9b9129e739 [POWERPC] typo fix and whitespace cleanup on mpc52xx-uart driver
Single typo fix and whitespace changes.  In preparation for heavy
changes to this driver when support for arch/powerpc is added.
Since the driver will be changing significantly anyway, then may
as well take the opportunity to clean it up first.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-12-05 09:53:07 +11:00
Jeff Garzik
c7bec5aba5 Various drivers' irq handlers: kill dead code, needless casts
- Eliminate casts to/from void*

- Eliminate checks for conditions that never occur.  These typically
  fall into two classes:

	1) Checking for 'dev_id == NULL', then it is never called with
	NULL as an argument.

	2) Checking for invalid irq number, when the only caller (the
	system) guarantees the irq handler is called with the proper
	'irq' number argument.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-10-06 15:00:58 -04:00
David Howells
7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00
Amol Lad
be618f550c [PATCH] ioremap balanced with iounmap for drivers/serial/mpc52xx_uart.c
ioremap must be balanced by an iounmap and failing to do so can result
in a memory leak.

Signed-off-by: Amol Lad <amol@verismonetworks.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:32 -07:00
Linus Torvalds
075395d228 Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-serial
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-serial:
  [SERIAL] Ensure 8250_pci quirks are not marked __devinit
  [SERIAL] Convert fifosize to an unsigned int
2006-07-03 21:31:05 -07:00
Thomas Gleixner
40663cc7f1 [PATCH] irq-flags: serial: Use the new IRQF_ constants
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-02 13:58:53 -07:00
Russell King
947deee890 [SERIAL] Convert fifosize to an unsigned int
Some UARTs have more than 255 bytes of FIFO, which can't be
represented by an unsigned char.  Change the kernel's internal
structure to be an unsigned int, but still export an unsigned char
via the TIOCGSERIAL ioctl.  If the TIOCSSERIAL ioctl provides a
fifo size of 0, assume this means "don't change" otherwise we'll
corrupt the larger fifo sizes.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-07-02 20:45:51 +01:00
Jörn Engel
6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Greg Kroah-Hartman
aa4148cfc7 [PATCH] devfs: Remove devfs support from the serial subsystem
Also fixes all serial drivers.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26 12:25:05 -07:00
Uwe Zeisberger
c30fe7f731 fix typos "wich" -> "which"
Signed-off-by: Uwe Zeisberger <zeisberg@informatik.uni-freiburg.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-03-24 18:23:14 +01:00
Russell King
d358788f3f [SERIAL] kernel console should send CRLF not LFCR
Glen Turner reported that writing LFCR rather than the more
traditional CRLF causes issues with some terminals.

Since this aflicts many serial drivers, extract the common code
to a library function (uart_console_write) and arrange for each
driver to supply a "putchar" function.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-20 20:00:09 +00:00
Alan Cox
33f0f88f1c [PATCH] TTY layer buffering revamp
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:59 -08:00
Sylvain Munaut
d62de3aa8a [PATCH] ppc32/serial: Change mpc52xx_uart.c to use the Low Density Serial port major
Before this patch we were just using the "classic" /dev/ttySx devices.
However when another on the system is loaded that uses those (like drivers for
serial PCMCIA), that creates a conflict for the minors.  Therefore, we now use
/dev/ttyPSC[0:5] (note the 0-based numbering !) with some minors we've been
assigned in the "Low Density Serial port major"

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:33:30 -08:00
Sylvain Munaut
2d8179c0b7 [PATCH] ppc32/serial: Fix compiler errors with GCC 4.x in mpc52xx_uart.c
Signed-off-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:33:30 -08:00
Andrey Volkov
38801e2e54 [SERIAL] Fix mpc52xx_uart.c
Fix copy-paste bug in mpc52xx_uart.c (pdev<->dev)

Signed-off-by: Andrey Volkov <avolkov@varma-el.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-12 22:04:06 +00:00
Russell King
3ae5eaec1d [DRIVER MODEL] Convert platform drivers to use struct platform_driver
This allows us to eliminate the casts in the drivers, and eventually
remove the use of the device_driver function pointer methods for
platform device drivers.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-11-09 22:32:44 +00:00
Russell King
d052d1beff Create platform_device.h to contain all the platform device details.
Convert everyone who uses platform_bus_type to include
linux/platform_device.h.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-29 19:07:23 +01:00
Russell King
9480e307cd [PATCH] DRIVER MODEL: Get rid of the obsolete tri-level suspend/resume callbacks
In PM v1, all devices were called at SUSPEND_DISABLE level.  Then
all devices were called at SUSPEND_SAVE_STATE level, and finally
SUSPEND_POWER_DOWN level.  However, with PM v2, to maintain
compatibility for platform devices, I arranged for the PM v2
suspend/resume callbacks to call the old PM v1 suspend/resume
callbacks three times with each level in order so that existing
drivers continued to work.

Since this is obsolete infrastructure which is no longer necessary,
we can remove it.  Here's an (untested) patch to do exactly that.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-28 09:52:56 -07:00