I found a problem of handling of modem status of atmel_serial driver.
With the commit 1ecc26 ("atmel_serial: split the interrupt handler"),
handling of modem status signal was splitted into two parts. The
atmel_tasklet_func() compares new status with irq_status_prev, but
irq_status_prev is not correct if signal status was changed while the port
is closed.
Here is a sequence to cause problem:
1. Remote side sets CTS (and DSR).
2. Local side close the port.
3. Local side clears RTS and DTR.
4. Remote side clears CTS and DSR.
5. Local side reopen the port. hw_stopped becomes 1.
6. Local side sets RTS and DTR.
7. Remote side sets CTS and DSR.
Then CTS change interrupt can be received, but since CTS bit in
irq_status_prev and new status is same, uart_handle_cts_change() will not
be called (so hw_stopped will not be cleared, i.e. cannot send any data).
I suppose irq_status_prev should be initialized at somewhere in open
sequence.
Itai Levi pointed out that we need to initialize atmel_port->irq_status
as well here. His analysis is as follows:
> Regarding the second part of the patch (which resets irq_status_prev),
> it turns out that both versions of the patch (mine and Atsushi's)
> still leave enough room for faulty behavior when opening the port.
>
> This is because we are not resetting both irq_status_prev and
> irq_status in atmel_startup() to CSR, which leads faulty behavior in
> the following sequences:
>
> First case:
> 1. closing the port while CTS line = 1 (TX not allowed)
> 2. setting CTS line = 0 (TX allowed)
> 3. opening the port
> 4. transmitting one char
> 5. Cannot transmit more chars, although CTS line is 0
>
> Second case:
> 1. closing the port while CTS line = 0 (TX allowed)
> 2. setting CTS line = 1 (TX not allowed)
> 3. opening the port
> 4. receiving some chars
> 5. Now we can transmit, although CTS line is 1
>
> This reason for this is that the tasklet is scheduled as a result of
> TX or RX interrupts (not a status change!), in steps 4 above. Inside
> the tasklet, the atmel_port->irq_status (which holds the value from
> the previous session) is compared to atmel_port->irq_status_prev.
> Hence, a status-change of the CTS line is faultily detected.
>
> Both cases were verified on 9260 hardware.
[haavard.skinnemoen@atmel.com: folded with patch from Itai Levi]
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Remy Bohmer <linux@bohmer.net>
Cc: Marc Pignat <marc.pignat@hevs.ch>
Cc: Itai Levi <itai.levi.devel@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following problem, related to hardware flow control (CTS/RTS):
Transmitting while CTS line is asserted in DMA mode, due to not checking
for tx-stopped condition.
We found these problems while testing the UARTs with hardware
flow-control.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: "Andrew Victor" <avictor.za@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The atmel_serial driver is mismanaging its clock by leaving it on at all
times ... the whole point of clock management is to leave it off unless
it's actively needed, which conserves power!!
Although the kernel doesn't actually hang without my fix, it does
discard quite a lot of early console output.
The result still looks correct:
usart users= 1 on 35000000 Hz, for atmel_usart.0
usart users= 0 off 35000000 Hz, for atmel_usart.2
when using ttyS0 as serial console.
[haavard.skinnemoen@atmel.com: Make sure clock is enabled early for console]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This problem seems to be unnoticed so far:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b3b708fa2780cd2b5d8266a8f0c3a1cab364d4d2
has changed the serial core behavior to not to suspend the port if the
device is enabled as a wakeup source. If the AT91 system goes to slow
clock mode, the port should be suspended always and the clocks should be
switched off. The patch attached updates the atmel_serial driver to match
the changes in serial core.
Also, the interrupts are disabled when the clock is disabled. If we
disable the clock with interrupts enabled, an interrupt may get stuck. If
this is the DBGU interrupt, this blocks the OR logic at system controller
and thus all other sysc interrupts.
Signed-off-by: Anti Sullin <anti.sullin@artecdesign.ee>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Michael Trimarchi <trimarchimichael@yahoo.it>
Cc: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The tty pointer has been moved into a tty_port field, so we need to use
->info->port.tty instead of just ->info->tty. Fixes these build errors:
David Brownell <david-b@pacbell.net> wrote:
> drivers/serial/atmel_serial.c: In function 'atmel_rx_from_ring':
> drivers/serial/atmel_serial.c:665: error: 'struct uart_info' has no member named 'tty'
> drivers/serial/atmel_serial.c: In function 'atmel_rx_from_dma':
> drivers/serial/atmel_serial.c:672: error: 'struct uart_info' has no member named 'tty'
> drivers/serial/atmel_serial.c: In function 'atmel_startup':
> drivers/serial/atmel_serial.c:797: error: 'struct uart_info' has no member named 'tty'
> make[2]: *** [drivers/serial/atmel_serial.o] Error 1
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Avoid dumping garbage to the serial port when the tty is flushed. This
tends to happen when rebooting from a serial console.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Funny things may happen if we stop the USART clock before the shifter is
empty. Prevent this from happening by waiting until the shifter is
completely drained before allowing suspend to continue.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
AVR32 doesn't have at91_suspend_entering_slow_clock(). Just assume the
clock will keep running for now.
David has a better solution for this, but this works for now. Leaving
the USART clock running won't prevent the PM code from entering deep
power-down modes anyway.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Andrew Victor <linux@maxim.org.za>
I made a change to u-boot that used the FP (Fractional Part) field of BRGR
to achieve more accurate baud rate generation. Unfortunately, the
atmel_serial driver looks at the whole BRGR register when trying to detect
the baud rate that the port is currently running at, so setting FP to a
nonzero value breaks the baud rate detection.
I'll sit on the u-boot patch for a while longer, but this is clearly a
bug in the atmel_serial driver which should be fixed.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Strange chars appear on the serial port when a printk and a printf
happens at the same time. This is caused by the pdc sending chars while
atmel_console_write (called from printk) is executing
Concurent access of uart and console to the same port leads to corrupted
data to be transmitted, so disable tx dma (PDC) while writing to the
console.
Signed-off-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I found a problem related to losing data during pdc transmission in
atmel_serial: connect ttyS1 with ttyS2 using a loopback cable, send 30
byte of packet from one to the other and waiting for 30 byte. On the
other side just read and echo the data received.
We always call atmel_tx_dma() from the tasklet regardless of what interrupt
triggered it.
Signed-off-by: michael <trimarchi@gandalf.sssup.it>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We should only return IRQ_HANDLED when we actually found something to
handle. This is important since the USART interrupt handler may be
shared with the timer interrupt on some chips.
Pointed-out-by: michael <trimarchi@gandalf.sssup.it>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When possible, pass the tty name to request_irq() so that the user can easily
distinguish the different serial ports in /proc/interrupts.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Tested-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As pointed out by David Brownell, we really ought to be using container_of
when converting from "struct uart_port *" to "struct atmel_uart_port *".
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Tested-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduced by atmel_serial-split-the-interrupt-handler.patch.
Thanks to michael <trimarchi@gandalf.sssup.it> for spotting it.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is based on the DMA-patch by Chip Coldwell for the AT91/AT32 serial
USARTS, with some tweaks to make it apply neatly on top of the other patches
in this series.
The RX and TX code has been moved to a tasklet and reworked a bit. Instead of
depending on the ENDRX and TIMEOUT bits in CSR, we simply grab as much data as
we can from the DMA buffers. I think this closes a race where the ENDRX bit
is set after we read CSR but before we read RPR, although I haven't confirmed
this.
Similarly, the two TX handlers (ENDTX and TXBUFE) have been combined into one.
Since the current code only uses a single TX buffer, there's no point in
handling those interrupts separately.
This also fixes a DMA sync bug in the original patch.
[linux@bohmer.net: rebased onto irq-splitup patch]
[hskinnemoen@atmel.com: moved to tasklet, fixed dma bug, misc cleanups]
[hskinnemoen@atmel.com: atmel_serial dma: Misc fixes and cleanups]
Signed-off-by: Remy Bohmer <linux@bohmer.net>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Tested-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Split up the interrupt handler of the serial port into a interrupt top-half
and a tasklet.
The goal is to get the interrupt top-half as short as possible to minimize
latencies on interrupts. But the old code also does some calls in the
interrupt handler that are not allowed on preempt-RT in IRQF_NODELAY context.
This handler is executed in this context because of the interrupt sharing with
the timer interrupt. The timer interrupt on Preempt-RT runs in IRQF_NODELAY
context.
The tasklet takes care of handling control status changes, pushing incoming
characters to the tty layer, handling break and other errors. It also handles
pushing TX data into the data register.
Reading the complete receive queue is still done in the top-half because we
never want to miss any incoming character.
[hskinnemoen@atmel.com: misc cleanups and simplifications]
Signed-off-by: Remy Bohmer <linux@bohmer.net>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Tested-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When an error happens in probe(), the clocks should be disabled, but
only if the port isn't already used as a console.
In remove(), the port struct shouldn't be freed because it's defined
statically.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Tested-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If BRGR is zero, the baud rate generator isn't running, so the boot loader
can't have initialized the port.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Tested-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace two instances of barrier() with cpu_relax() since that's the right
thing to do when busy-waiting. This does not actually change anything since
cpu_relax() is defined as barrier() on both ARM and AVR32.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Tested-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Clean up the atmel_serial driver to conform the coding rules. It contains no
functional change.
Signed-off-by: Remy Bohmer <linux@bohmer.net>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Tested-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently early kernel messages, i.e., those from uncompression, go to the
debugging UART. And if it is enabled in the platform configuration, but
not initialized by the bootloader, the machine hangs, waiting for UART
status change. Besides, having those messages on another UART - typically
the console UART - may be preferrable. This patch allows selecting the
UART in kernel configuration.
Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Remove annoying build warnings about unused variables in atmel_serial,
which afflict both AT91 and AVR32 builds.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The RXBRK field in the AT91/AT32 USART status register has the
following definition according to e.g. the AT32AP7000 data sheet:
RXBRK: Break Received/End of Break
0: No Break received or End of Break detected since the last RSTSTA.
1: Break Received or End of Break detected since the last RSTSTA.
Thus, for each break, the USART sets the RXBRK bit twice. This patch
modifies the driver to report the break event to the serial core only
once by keeping track of whether a break condition is currently
active. The break_active flag is reset as soon as a character is
received, so even if we miss the start-of-break interrupt this should
do the right thing.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <andrew@sanpeople.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ivan Kuten <ivan.kuten@promwad.com>
Cc: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Cc: Patrice Vilchez <patrice.vilchez@rfo.atmel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow slower serial baud-rates by switching the UART clock from MCK to
MCK/8.
Based on patches by Mike Wolfram and Russell King.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (117 commits)
[ARM] 4058/2: iop32x: set ->broken_parity_status on n2100 onboard r8169 ports
[ARM] 4140/1: AACI stability add ac97 timeout and retries
[ARM] 4139/1: AACI record support
[ARM] 4138/1: AACI: multiple channel support for IRQ handling
[ARM] 4211/1: Provide a defconfig for ns9xxx
[ARM] 4210/1: base for new machine type "NetSilicon NS9360"
[ARM] 4222/1: S3C2443: Remove reference to missing S3C2443_PM
[ARM] 4221/1: S3C2443: DMA support
[ARM] 4220/1: S3C24XX: DMA system initialised from sysdev
[ARM] 4219/1: S3C2443: DMA source definitions
[ARM] 4218/1: S3C2412: fix CONFIG_CPU_S3C2412_ONLY wrt to S3C2443
[ARM] 4217/1: S3C24XX: remove the dma channel show at startup
[ARM] 4090/2: avoid clash between PXA and SA1111 defines
[ARM] 4216/1: add .gitignore entries for ARM specific files
[ARM] 4214/2: S3C2410: Add Armzone QT2410
[ARM] 4215/1: s3c2410 usb device: per-platform vbus_draw
[ARM] 4213/1: S3C2410 - Update definition of ADCTSC_XY_PST
[ARM] 4098/1: ARM: rtc_lock only used with rtc_cmos
[ARM] 4137/1: Add kexec support
[ARM] 4201/1: SMP barriers pair needed for the secondary boot process
...
Fix up conflict due to typedef removal in sound/arm/aaci.h
Access to chip-internal registers should always be native-endian. This is
especially important for AVR32 since it's a big-endian architecture and the
non-raw readl() and writel() macros are defined to do little-endian
accesses.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The Atmel AT91 and AVR32 processor architectures share many of the same
peripherals. The PDC (Peripheral Data Controller) registers are also
implemented within in a number of the on-chip peripherals (eg, USART,
MMC, SPI, SSC, etc).
In a attempt not to duplicate the register definitions in each
peripheral, or in each architecture, the at91_pdc.h header in
asm-arm/arch-at91 and asm-avr32/arch-at32ap has been replaced with
linux/atmel_pdc.h.
The definitions have also been renamed from AT91_PDC_* to ATMEL_PDC_*,
and the drivers updated accordingly.
Original patch from Nicolas Ferre.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch fixes the unbalanced calls to enable_irq_wake() and
disable_irq_wake() in the AT91 (and AVR32) serial driver.
It should resolve these kernel messages:
Unbalanced IRQ x wake disable
BUG: warning at kernel/irq/manage.c:167/set_irq_wake()
Original patch from Marc Pignat.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
A couple of whitespace cleanups, mainly in the AT91 header files.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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>
1. The CPU identification has moved from <system.h> to <cpu.h>.
2. AT91RM9200_BASE_US0 is only defined if we are compiling in support
for the AT91RM9200. Therefore we need to replace the CONFIG_ARM ifdef
with CONFIG_ARCH_AT91RM9200
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch updates the drivers (and other files) which include the
hardware headers. This fixes the breakage introduced in patches 3950/1
and 3951/1 (those patches were getting big).
The AVR32 architecture uses the same serial driver and had its own copy
of at91rm9200_pdc.h. Renamed it to at91_pdc.h
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch replaces the arch_identify() in system.h with a set of
cpu_is_XXX() macro's. This allows for compile-time checking of the
target AT91 processor.
Original patch from David Brownell.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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)
The atmel_console_get_options() function initializes the baud,
parity and bits settings from the actual hardware setup, in
case it has been initialized by a e.g. boot loader.
The baud rate, however, is not necessarily exactly equal to one of
the standard baud rates (115200, etc.) This means that the baud rate
calculated by this function may be slightly higher or slightly lower
than one of the standard baud rates.
If the baud rate is slightly lower than the target, this causes
problems when uart_set_option() tries to match the detected baud rate
against the standard baud rate, as it will always select a baud rate
that is lower or equal to the target rate. For example if the
detected baud rate is slightly lower than 115200, usart_set_options()
will select 57600.
This patch fixes the problem by subtracting 1 from the value in BRGR
when calculating the baud rate. The detected baud rate will thus
always be higher than the nearest standard baud rate, and
uart_set_options() will end up doing the right thing.
Tested on ATSTK1000 and AT91RM9200-EK boards. Both are broken without
this patch.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make CONFIG_SERIAL_ATMEL selectable on AVR32 and #ifdef out some ARM-
specific code in the driver.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In order to initialize the serial console early, the atmel_serial
driver had to do a hack where it compared the physical address of the
port with an address known to be permanently mapped, and used it as a
virtual address. This got around the limitation that ioremap() isn't
always available when the console is being initalized.
This patch removes that hack and replaces it with a new "regs" field
in struct atmel_uart_data that the board-specific code can initialize
to a fixed virtual mapping for platform devices where this is possible.
It also initializes the DBGU's regs field with the address the driver
used to check against.
On AVR32, the "regs" field is initialized from the physical base
address when this it can be accessed through a permanently 1:1 mapped
segment, i.e. the P4 segment.
If regs is NULL, the console initialization is delayed until the "real"
driver is up and running and ioremap() can be used.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Rename at91_register_uart_fns and associated structs and variables
to make it consistent with the atmel_ prefix used by the rest of
the driver.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The at91_serial driver can be used with both AT32 and AT91 devices
from Atmel and has therefore been renamed atmel_serial. The only
thing left is to rename PORT_AT91 PORT_ATMEL.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Prefix all internal functions and variables with atmel_ instead of
at91_.
The at91_register_uart_fns() stuff is left as is since I can't find
any actual users of it.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
