linux-toradex.git/drivers/gpio/gpiolib.c, branch v2.6.31.4

gpio: gpio_{request,free}() now required (feature removal)

2009-04-03T02:04:51+00:00

We want to phase out the GPIO "autorequest" mechanism in gpiolib and
require all callers to use gpio_request().

 - Update feature-removal-schedule
 - Update the documentation now
 - Convert the relevant pr_warning() in gpiolib to a WARN()
   so folk using this mechanism get a noisy stack dump

Some drivers and board init code will probably need to change.
Implementations not using gpiolib will still be fine; they are already
required to implement gpio_{request,free}() stubs.

Signed-off-by: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

gpiolib: allow GPIOs to be named

2009-04-03T02:04:51+00:00

Allow GPIOs in GPIOLIB chips to be named.  This name is then used when the
GPIO is exported to sysfs, although it could be used elsewhere if deemed
useful.

Signed-off-by: Daniel Silverstone 
Cc: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

gpiolib: fix request related issue

2009-01-30T02:04:43+00:00

Fix request-already-requested handling in gpio_request().

Signed-off-by: Magnus Damm 
Acked-by: David Brownell 
Cc: 		[2.6.28.x]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

gpio: struct device - replace bus_id with dev_name(), dev_set_name()

2009-01-06T18:44:42+00:00

Signed-off-by: Kay Sievers 
Signed-off-by: Greg Kroah-Hartman

gpiolib: extend gpio label column width in debugfs file

2008-11-20T02:49:57+00:00

There are already various drivers having bigger label than 12 bytes.  Most
of them fit well under 20 bytes but make column width exact so that
oversized labels don't mess up output alignment.

Signed-off-by: Jarkko Nikula 
Acked-by: David Brownell 
Cc: 		[2.6.26.x, 2.6.26.x, 2.6.27.x]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'genirq-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2008-10-20T20:23:01+00:00

This merges branches irq/genirq, irq/sparseirq-v4, timers/hpet-percpu
and x86/uv.

The sparseirq branch is just preliminary groundwork: no sparse IRQs are
actually implemented by this tree anymore - just the new APIs are added
while keeping the old way intact as well (the new APIs map 1:1 to
irq_desc[]).  The 'real' sparse IRQ support will then be a relatively
small patch ontop of this - with a v2.6.29 merge target.

* 'genirq-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (178 commits)
  genirq: improve include files
  intr_remapping: fix typo
  io_apic: make irq_mis_count available on 64-bit too
  genirq: fix name space collisions of nr_irqs in arch/*
  genirq: fix name space collision of nr_irqs in autoprobe.c
  genirq: use iterators for irq_desc loops
  proc: fixup irq iterator
  genirq: add reverse iterator for irq_desc
  x86: move ack_bad_irq() to irq.c
  x86: unify show_interrupts() and proc helpers
  x86: cleanup show_interrupts
  genirq: cleanup the sparseirq modifications
  genirq: remove artifacts from sparseirq removal
  genirq: revert dynarray
  genirq: remove irq_to_desc_alloc
  genirq: remove sparse irq code
  genirq: use inline function for irq_to_desc
  genirq: consolidate nr_irqs and for_each_irq_desc()
  x86: remove sparse irq from Kconfig
  genirq: define nr_irqs for architectures with GENERIC_HARDIRQS=n
  ...

gpiolib: fix oops in gpio_get_value_cansleep()

2008-10-20T15:52:36+00:00

We can get the following oops from gpio_get_value_cansleep() when a GPIO
controller doesn't provide a get() callback:

 Unable to handle kernel paging request for instruction fetch
 Faulting instruction address: 0x00000000
 Oops: Kernel access of bad area, sig: 11 [#1]
 [...]
 NIP [00000000] 0x0
 LR [c0182fb0] gpio_get_value_cansleep+0x40/0x50
 Call Trace:
 [c7b79e80] [c0183f28] gpio_value_show+0x5c/0x94
 [c7b79ea0] [c01a584c] dev_attr_show+0x30/0x7c
 [c7b79eb0] [c00d6b48] fill_read_buffer+0x68/0xe0
 [c7b79ed0] [c00d6c54] sysfs_read_file+0x94/0xbc
 [c7b79ef0] [c008f24c] vfs_read+0xb4/0x16c
 [c7b79f10] [c008f580] sys_read+0x4c/0x90
 [c7b79f40] [c0013a14] ret_from_syscall+0x0/0x38

It's OK to request the value of *any* GPIO; most GPIOs are bidirectional,
so configuring them as outputs just enables an output driver and doesn't
disable the input logic.

So the problem is that gpio_get_value_cansleep() isn't making the same
sanity check that gpio_get_value() does: making sure this GPIO isn't one
of the atypical "no input logic" cases.

Reported-by: Anton Vorontsov 
Signed-off-by: David Brownell 
Cc: 		[2.6.27.x, 2.6.26.x, 2.6.25.x]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

gpio: modify sysfs gpio export so that "value" displays as 0 or 1

2008-10-20T15:52:36+00:00

gpiolib can export GPIOs to userspace via sysfs.  This patch modifies the
gpio_value_show() so that any non-zero value is explicitly printed as "1",
rather than whatever numerical value the lower-level driver returns.

Signed-off-by: Steve Falco 
Signed-off-by: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

gpiolib: request/free hooks

2008-10-16T18:21:40+00:00

Add a new internal mechanism to gpiolib to support low power
operations by letting gpio_chip instances see when their GPIOs
are in use.  When no GPIOs are active, chips may be able to
enter lower powered runtime states by disabling clocks and/or
power domains.

Signed-off-by: David Brownell 
Cc: "Magnus Damm" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

gpiolib: gpio_to_irq() hooks

2008-10-16T18:21:40+00:00

Add a new gpiolib mechanism: gpio_chip instances can provide mappings
between their (input) GPIOs and any associated IRQs.  This makes it easier
for platforms to support IRQs that are provided by board-specific external
chips instead of as part of their core (such as SOC-integrated GPIOs).

Also update the irq_to_gpio() description, saying to avoid it because it's
not always supported.

Signed-off-by: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds