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path: root/drivers/serial/s3c2410.c
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2006-10-05IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells
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)
2006-09-18[ARM] 3793/1: S3C2412: fix wrong serial info structBen Dooks
Patch from Ben Dooks The S3C2440 serial info struct is being passed through the S3C2412 serial info struct probe routine. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Thomas Glexiner <tglx@linutronix.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-26[PATCH] devfs: Remove devfs support from the serial subsystemGreg Kroah-Hartman
Also fixes all serial drivers. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-24[ARM] 3639/1: S3C2412: serial port supportBen Dooks
Patch from Ben Dooks Serial port support for the on-board UART blocks on the Samsung S3C2412 and S3C2413 UARTs. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-18[ARM] 3559/1: S3C2442: core and serial portBen Dooks
Patch from Ben Dooks Core support for the Samsung S3C2442, and the serial port driver update to allow the serial port blocks to be used. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-22Merge master.kernel.org:/home/rmk/linux-2.6-serialLinus Torvalds
* master.kernel.org:/home/rmk/linux-2.6-serial: [SERIAL] Merge avlab serial board entries in parport_serial [SERIAL] kernel console should send CRLF not LFCR
2006-03-20[PATCH] handle errors returned by platform_get_irq*()David Vrabel
platform_get_irq*() now returns on -ENXIO when the resource cannot be found. Ensure all users of platform_get_irq*() handle this error appropriately. Signed-off-by: David Vrabel <dvrabel@arcom.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-20[SERIAL] kernel console should send CRLF not LFCRRussell King
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>
2006-02-08[ARM] 3283/1: S3C2400 - defines the number of serial portsLucas Correia Villa Real
Patch from Lucas Correia Villa Real This patch defines the number of serial ports on the S3C2400. Signed-off-by: Lucas Correia Villa Real <lucasvr@gobolinux.org> Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-26[ARM] 3266/1: S3C2400 - adds macro S3C24XXLucas Correia Villa Real
Patch from Lucas Correia Villa Real This patch defines S3C2400 memory map and adds a S3C24XX macro for common resources between S3C2400, S3C2410 and S3C2440 cpus. Signed-off-by: Lucas Correia Villa Real <lucasvr@gobolinux.org> Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-10[PATCH] TTY layer buffering revampAlan Cox
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>
2006-01-07[ARM] Move asm/hardware/clock.h to linux/clk.hRussell King
This is needs to be visible to other architectures using the AMBA bus and peripherals. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-03[ARM] Remove clk_use()/clk_unuse()Russell King
It seems that clk_use() and clk_unuse() are additional complexity which isn't required anymore. Remove them from the clock framework to avoid the additional confusion which they cause, and update all ARM machine types except for OMAP. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-09[DRIVER MODEL] Convert platform drivers to use struct platform_driverRussell King
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>
2005-10-29Create platform_device.h to contain all the platform device details.Russell King
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>
2005-10-28[PATCH] DRIVER MODEL: Get rid of the obsolete tri-level suspend/resume callbacksRussell King
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>
2005-10-12[ARM] 2976/1: S3C2410: add static to functions in serial driverBen Dooks
Patch from Ben Dooks The s3c2410 serial driver is missing static declerations on several functions that are not exported, and have no need of being exported outside the driver Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-10-10[ARM] 2964/1: S3C2410 - serial: add .owner to driverBen Dooks
Patch from Ben Dooks Initialise the driver's .owner field so that the device driver can be referenced to the module that owns it Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-09-30Merge master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds
2005-09-29[ARM] Don't include mach-types.h unnecessarilyRussell King
It's pointless to include mach-types.h if you're not going to use anything from it. These references were removed as a result of: grep -lr 'asm/mach-types\.h' . | xargs grep -L 'machine_is_\|MACH_TYPE_\|MACHINE_START\|machine_type' Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-09-25[ARM] 2933/1: S3C2410 - fix serial port warningsBen Dooks
Patch from Ben Dooks Fix the following warnings produced from drivers/char/s3c2410.c. drivers/serial/s3c2410.c:757: warning: 'clk' may be used uninitialized drivers/serial/s3c2410.c:756: warning: 'clksrc' may be used uninitialized Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-08-31[SERIAL] Clean up and fix tty transmission start/stopingRussell King
The start_tx and stop_tx methods were passed a flag to indicate whether the start/stop was from the tty start/stop callbacks, and some drivers used this flag to decide whether to ask the UART to immediately stop transmission (where the UART supports such a feature.) There are other cases when we wish this to occur - when CTS is lowered, or if we change from soft to hard flow control and CTS is inactive. In these cases, this flag was false, and we would allow the transmitter to drain before stopping. There is really only one case where we want to let the transmitter drain before disabling, and that's when we run out of characters to send. Hence, re-jig the start_tx and stop_tx methods to eliminate this flag, and introduce new functions for the special "disable and allow transmitter to drain" case. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-07-03[PATCH] ARM: 2785/1: S3C24XX - serial calls request_irq() with IRQs disabledBen Dooks
Patch from Ben Dooks The request_irq() function is called by s3c24xx uart driver with the local IRQs disabled. The request_irq() function can allocate memory via kmalloc(), and this may sleep causing a warning about sleeping in an invalid context. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-06-23[PATCH] ARM: 2728/1: S3C2410 - fix constant warning on serial device nameBen Dooks
Patch from Ben Dooks Remove warning of casting `const char *` to a `char *` type. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-05-09[PATCH] Serial: Add uart_insert_char()Russell King
Add uart_insert_char(), which handles inserting characters into the flip buffer. This helper function handles the correct semantics for handling overrun in addition to inserting normal characters. Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-26[PATCH] Serial: Ensure error paths are marked with unlikely()Russell King
Ensure ARM serial driver error paths are marked with the unlikely() compiler hint. Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-16[PATCH] fix u32 vs. pm_message_t in drivers/Pavel Machek
-rc2-mm1 still contains few places where u32 and pm_message_t. This fixes drivers/serial [should change no code]. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!