This patch adds functionality to the gpio-lib subsystem to make it
possible to enable the gpio-lib code even if the architecture code didn't
request to get it built in.
The archtitecture code does still need to implement the gpiolib accessor
functions in its asm/gpio.h file. This patch adds the implementations for
x86 and PPC.
With these changes it is possible to run generic GPIO expansion cards on
every architecture that implements the trivial wrapper functions. Support
for more architectures can easily be added.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Brownell <david-b@pacbell.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Samuel Ortiz <sameo@openedhand.com>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds a simple sysfs interface for GPIOs.
/sys/class/gpio
/export ... asks the kernel to export a GPIO to userspace
/unexport ... to return a GPIO to the kernel
/gpioN ... for each exported GPIO #N
/value ... always readable, writes fail for input GPIOs
/direction ... r/w as: in, out (default low); write high, low
/gpiochipN ... for each gpiochip; #N is its first GPIO
/base ... (r/o) same as N
/label ... (r/o) descriptive, not necessarily unique
/ngpio ... (r/o) number of GPIOs; numbered N .. N+(ngpio - 1)
GPIOs claimed by kernel code may be exported by its owner using a new
gpio_export() call, which should be most useful for driver debugging.
Such exports may optionally be done without a "direction" attribute.
Userspace may ask to take over a GPIO by writing to a sysfs control file,
helping to cope with incomplete board support or other "one-off"
requirements that don't merit full kernel support:
echo 23 > /sys/class/gpio/export
... will gpio_request(23, "sysfs") and gpio_export(23);
use /sys/class/gpio/gpio-23/direction to (re)configure it,
when that GPIO can be used as both input and output.
echo 23 > /sys/class/gpio/unexport
... will gpio_free(23), when it was exported as above
The extra D-space footprint is a few hundred bytes, except for the sysfs
resources associated with each exported GPIO. The additional I-space
footprint is about two thirds of the current size of gpiolib (!). Since
no /dev node creation is involved, no "udev" support is needed.
Related changes:
* This adds a device pointer to "struct gpio_chip". When GPIO
providers initialize that, sysfs gpio class devices become children of
that device instead of being "virtual" devices.
* The (few) gpio_chip providers which have such a device node have
been updated.
* Some gpio_chip drivers also needed to update their module "owner"
field ... for which missing kerneldoc was added.
* Some gpio_chips don't support input GPIOs. Those GPIOs are now
flagged appropriately when the chip is registered.
Based on previous patches, and discussion both on and off LKML.
A Documentation/ABI/testing/sysfs-gpio update is ready to submit once this
merges to mainline.
[akpm@linux-foundation.org: a few maintenance build fixes]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This mirrors the functionality that driver_for_each_device has as well.
We add a start variable, and all callers of the function are fixed up at
the same time.
The block layer will be using this new functionality in a follow-on
patch.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The new-style max6875 driver implements the optional detect() callback
to cover the use cases of the legacy driver. I'm curious if anyone
really needs this though, so it might be removed in the feature.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style pca9539 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Warning: users will now have to use the force module parameter to get
the driver to attach to their device. That's not a bad thing as these
devices can't be detected anyway.
Note that this doesn't change the fact that this driver is deprecated
in favor of gpio/pca953x.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style pcf8575 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Warning: users will now have to use the force module parameter to get
the driver to attach to their device. That's not a bad thing as these
devices can't be detected anyway.
Note that this doesn't change the fact that this driver is deprecated
in favor of gpio/pcf857x.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style pcf8574 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Warning: users will now have to use the force module parameter to get
the driver to attach to their device. That's not a bad thing as these
devices can't be detected anyway.
Note that this doesn't change the fact that this driver is deprecated
in favor of gpio/pcf857x.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style pcf8591 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style eeprom driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Clear i2c_adapter.dev on adapter removal. This makes it possible to
re-add the adapter at a later point, which some drivers
(i2c-amd756-s4882, i2c-nforce2-s4985) actually do.
This fixes a bug reported by John Stultz here:
http://lkml.org/lkml/2008/7/15/720
and by Ingo Molar there:
http://lkml.org/lkml/2008/7/16/78
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6: (56 commits)
i2c: Add detection capability to new-style drivers
i2c: Call client_unregister for new-style devices too
i2c: Clean up old chip drivers
i2c-ibm_iic: Register child nodes
i2c: New-style EEPROM driver using device IDs
i2c: Export the i2c_bus_type symbol
i2c-au1550: Fix PM support
i2c-dev: Delete empty detach_client callback
i2c: Drop stray references to lm_sensors
i2c: Check for ACPI resource conflicts
i2c-ocores: basic PM support
i2c-sibyte: SWARM I2C board initialization
i2c-i801: Fix handling of error conditions
i2c-i801: Rename local variable temp to status
i2c-i801: Properly report bus arbitration loss
i2c-i801: Remove verbose debugging messages
i2c-algo-pcf: Drop unused struct members
i2c-algo-pcf: Multi-master lost-arbitration improvement
i2c: Deprecate the legacy gpio drivers
i2c-pxa: Initialize early
...
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (241 commits)
[ARM] 5171/1: ep93xx: fix compilation of modules using clocks
[ARM] 5133/2: at91sam9g20 defconfig file
[ARM] 5130/4: Support for the at91sam9g20
[ARM] 5160/1: IOP3XX: gpio/gpiolib support
[ARM] at91: Fix NAND FLASH timings for at91sam9x evaluation kits.
[ARM] 5084/1: zylonite: Register AC97 device
[ARM] 5085/2: PXA: Move AC97 over to the new central device declaration model
[ARM] 5120/1: pxa: correct platform driver names for PXA25x and PXA27x UDC drivers
[ARM] 5147/1: pxaficp_ir: drop pxa_gpio_mode calls, as pin setting
[ARM] 5145/1: PXA2xx: provide api to control IrDA pins state
[ARM] 5144/1: pxaficp_ir: cleanup includes
[ARM] pxa: remove pxa_set_cken()
[ARM] pxa: allow clk aliases
[ARM] Feroceon: don't disable BPU on boot
[ARM] Orion: LED support for HP mv2120
[ARM] Orion: add RD88F5181L-FXO support
[ARM] Orion: add RD88F5181L-GE support
[ARM] Orion: add Netgear WNR854T support
[ARM] s3c2410_defconfig: update for current build
[ARM] Acer n30: Minor style and indentation fixes.
...
This includes PXA work up to the SPI changes for the initial merge,
since e172274ccc depends on the SPI
tree being merged.
Conflicts:
arch/arm/configs/em_x270_defconfig
arch/arm/configs/xm_x270_defconfig
Add a mechanism to let new-style i2c drivers optionally autodetect
devices they would support on selected buses and ask i2c-core to
instantiate them. This is a replacement for legacy i2c drivers, much
cleaner.
Where drivers had to implement both a legacy i2c_driver and a
new-style i2c_driver so far, this mechanism makes it possible to get
rid of the legacy i2c_driver and implement both enumerated and
detected device support with just one (new-style) i2c_driver.
Here is a quick conversion guide for these drivers, step by step:
* Delete the legacy driver definition, registration and removal.
Delete the attach_adapter and detach_client methods of the legacy
driver.
* Change the prototype of the legacy detect function from
static int foo_detect(struct i2c_adapter *adapter, int address, int kind);
to
static int foo_detect(struct i2c_client *client, int kind,
struct i2c_board_info *info);
* Set the new-style driver detect callback to this new function, and
set its address_data to &addr_data (addr_data is generally provided
by I2C_CLIENT_INSMOD.)
* Add the appropriate class to the new-style driver. This is
typically the class the legacy attach_adapter method was checking
for. Class checking is now mandatory (done by i2c-core.) See
<linux/i2c.h> for the list of available classes.
* Remove the i2c_client allocation and freeing from the detect
function. A pre-allocated client is now handed to you by i2c-core,
and is freed automatically.
* Make the detect function fill the type field of the i2c_board_info
structure it was passed as a parameter, and return 0, on success. If
the detection fails, return -ENODEV.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
We call adapter->client_register for both legacy and new-style i2c
devices, however we only call adapter->client_unregister for legacy
drivers. This doesn't make much sense. Usually, drivers will undo
in client_unregister what they did in client_register, so we should
call neither or both for every given i2c device.
In order to ease the transition from legacy to new-style devices, it
seems preferable to actually call both.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>
Clean up old i2c chip drivers:
* Name the i2c_client "client" instead of "new_client".
* Drop useless initializations to 0.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This patch completes the conversion of the IBM IIC driver to an
of-platform driver.
It removes the index from the IBM IIC driver and makes it an unnumbered
driver. It then calls of_register_i2c_devices to properly register all
the child nodes in the DTS.
Signed-off-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Add a new-style driver for most I2C EEPROMs, giving sysfs read/write
access to their data. Tested with various chips and clock rates.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Export the root of the i2c bus so that PowerPC device tree code can
iterate over devices on the i2c bus.
Signed-off-by: Jon Smirl <jonsmirl@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Fix driver power management:
- suspend the PSC while driver is idle.
- move PSC init/deinit to separate functions, as PSC must be
initialized/shutdown on resume/suspend.
Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Implementing detach_client is optional, so there is no point in
an empty implementation.
Likewise, i2c driver IDs are optional, and we don't need one.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Check for ACPI resource conflicts in i2c bus drivers. I've included
all recent SMBus master drivers for PC hardware.
I've voluntarily left out:
* Drivers that don't run on PCs: they can't conflict with ACPI.
* Bit-banged bus device drivers: it's very unlikely that ACPI would
deal with such buses.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Basic PM support: reinit the core on resume, disable it on suspend.
Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The standard rtc-m41t80.c driver cannot be used with the SWARM as it is,
because the board does not provide setup information for the I2C core.
As a result the bus and the address to probe for the M41T80 chip is not
known.
Here is a set of changes that fix the problem:
1. swarm-i2c.c -- SWARM I2C board setup, currently for the M41T80 chip on
the bus #1 only (there is a MAX6654 temperature sensor on the bus #0
which may be added in the future if we have a driver for that chip).
2. The i2c-sibyte.c BCM1250A SMBus controller driver now registers its
buses as numbered so that board setup is correctly applied.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Move the check of pre-transaction and post-transaction conditions to
separate functions, and adjust them a bit. Having dedicated functions
for that ensures that errors are handled in a consistent way.
Bit HOST_BUSY of the status register is read-only, so writing to it is
certainly not going to clear it. If this bit is set then we simply
don't want to start the transaction, as it means that somebody else
(ACPI, SMM?) is already using the controller.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Bit BUS_ERR of the status register means that the ICH host controller
lost the arbitration. Report this event as such.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Dumping the register values before and after every transaction was
useful during driver development but now it's only spamming the log.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Struct members udelay and timeout aren't used anywhere, so drop them.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Eric Brower <ebrower@gmail.com>
Improve lost-arbitration handling of PCF8584. This is necessary for
support of a currently out-of-kernel driver for Sun Microsystems E250
environmental management; perhaps others.
Signed-off-by: Eric Brower <ebrower@gmail.com>
Acked-by: Dan Smolik <marvin@mydatex.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The legacy pcf8574 and pcf8575 drivers should be avoided
on systems using the new gpiolib code, and generally deprecated
in the same way the legacy pca9539 driver is deprecated.
Also, correct the pca9539 deprecation to match the current name
of the preferred driver: pca953x, supporting several more chips.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Initialize the pxa i2c bus during subsystem initialization to make it
available during driver initialization (e.g. display powerup for pxafb).
Signed-off-by: Uli Luckas <u.luckas@road.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Enable the IBM I2C driver for all PPC4xx variants by adding
"ibm,iic" to the compatible list. This way all currently available
arch/powerpc 4xx ports can make use of this driver without any changes.
Additionally all "other" compatible entries are removed since they are
not needed anymore.
Currently all 4xx PPC's have the same compatible I2C macro. If at some
time an incompatibility is detected we can take care of this with an
additional property.
Signed-off-by: Stefan Roese <sr@denx.de>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The deprecated OCP style driver part is used by the "old" arch/ppc
platform. This platform is scheduled for removal in June/July this year.
This patch now removes the OCP driver part from the IBM I2C driver.
Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
When I2C block reads are not supported by the underlying adapter, use
SMBus read word transactions instead of consecutive byte reads.
Reasons for this change are:
* The consecutive byte read approach is not safe on multi-master buses.
* While consecutive byte reads have less overhead if you only count the
bytes on the bus, it takes more than twice as many transactions as
with SMBus read word transactions, and each transaction has a cost:
taking and releasing the adapter mutex, and for polling drivers,
waiting for the transaction to complete.
This change yields a significant performance boost at HZ=250 with
EEPROMs on an Intel 82801 bus (basically twice as fast.)
SMBus read word transactions are widely supported so I don't expect
compatibility issues.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Let general purpose I2C/SMBus bus drivers add SPD to their class. Once
this is done, we will be able to tell the eeprom driver to only probe
for SPD EEPROMs and similar on these buses.
Note that I took a conservative approach here, adding I2C_CLASS_SPD to
many drivers that have no idea whether they can host SPD EEPROMs or not.
This is to make sure that the eeprom driver doesn't stop probing buses
where SPD EEPROMs or equivalent live.
So, bus driver maintainers and users should feel free to remove the SPD
class from drivers those buses never have SPD EEPROMs or they don't
want the eeprom driver to bind to them. Likewise, feel free to add the
SPD class to any bus driver I might have missed.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Bugfixes to the i2c-cpm driver
- enable correct interrupts (I2CER_TXE instead of I2CER_BUSY)
- replace forgotten iic with i2c
- prefix debug-output on init with 0x and add frequency
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This driver uses the port of 2.4 code from Vitaly Bordug
<vitb@kernel.crashing.org> and the actual algorithm used by the i2c
driver of the DBox code on cvs.tuxboc.org from Felix Domke
(tmbinc@gmx.net) and Gillem (htoa@gmx.net) converted to an
of_platform_driver. Tested on CPM1 (MPC823 on dbox2 hardware) and
CPM2 (MPC8272).
Signed-off-by: Jochen Friedrich <jochen@scram.de>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This is part of the effort to get rid of the BKL.
[JD: In fact i2c-dev doesn't need more locking than is already done
for the other i2c drivers, so we can simply switch to unlocked_ioctl.]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
New i2c bus driver for the Intel SCH chipsets (AF82US15W, AF82US15L,
AF82UL11L).
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Use list_for_each_entry_safe() in i2c_del_adapter() and i2c_del_driver().
Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
