Commit Graph

18 Commits

Author SHA1 Message Date
Uwe Kleine-König
0b336cea56 w1-gpio: handle of_get_gpio() returning -EPROBE_DEFER better
of_get_gpio() might return -EPROBE_DEFER meaning that the driver
providing the gpio isn't ready yet. If that happens for the first gpio
the resulting kernel output without this patch is:

	w1-gpio somename: Failed to parse DT
	platform somename: Driver w1-gpio requests probe deferral

The first message is misleading and so is suppressed with this patch.

Further if determining the gpio to switch the external pullup yields
-EPROBE_DEFER this error should be passed back to the caller instead of
just continuing without pullup.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-15 12:08:38 -08:00
Evgeny Boger
3089a4c8d3 drivers/w1/masters/w1-gpio.c: add strong pullup emulation
Strong pullup is emulated by driving pin logic high after write command
when using tri-state push-pull GPIO.

Signed-off-by: Evgeny Boger <boger@contactless.ru>
Cc: Greg KH <greg@kroah.com>
Acked-by: David Fries <david@fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:37:04 -08:00
Jingoo Han
c853b167e6 drivers/w1/masters/w1-gpio.c: use dev_get_platdata()
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.  This is a cosmetic change to make
the code simpler and enhance the readability.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:21 +09:00
Markus Pargmann
d27f25c9c2 w1-gpio: Use devm_* functions
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29 16:58:18 -07:00
Markus Pargmann
7cf1a122b2 w1-gpio: Detect of_gpio_error for first gpio
The first DT gpio is necessary for this driver, but errors returned for
of_get_gpio are ignored.

This patch adds a return value check for the first of_get_gpio.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29 16:58:18 -07:00
Fabio Estevam
5e6e78e27a w1-gpio: Let device core handle pinctrl
Since commit ab78029 (drivers/pinctrl: grab default handles from device core)
we can rely on device core for handling pinctrl, so remove
devm_pinctrl_get_select_default() from the driver.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-21 10:07:54 -07:00
Johan Hovold
34ccd8738e w1-gpio: fix unused variable warning
Commit 8a1861d997 ("w1-gpio: Simplify & get rid of defines") removed the
compile guards from the device-tree id table, thereby generating a
warning when building without device-tree support.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-12 16:20:46 -07:00
Johan Hovold
01230551e7 w1-gpio: remove erroneous __exit and __exit_p()
Commit 8a1861d997 ("w1-gpio: Simplify & get rid of defines") changed
(apparently unknowingly) the driver to a hotpluggable platform-device
driver but did not not update the section markers for probe and remove
(to __devinit/exit, which have since been removed). A later commit fixed
the section mismatch for probe, but left remove marked with __exit.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Cc: stable <stable@vger.kernel.org> # 3.8
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-12 16:20:46 -07:00
Hauke Mehrtens
06a8f1feb9 w1-gpio: fix section mismatch
This fixes the following section mismatch:

WARNING: drivers/w1/masters/w1-gpio.o(.data+0x188): Section mismatch in
reference from the variable w1_gpio_driver to the function
.init.text:w1_gpio_probe()
The variable w1_gpio_driver references
the function __init w1_gpio_probe()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-30 00:06:06 -05:00
Pantelis Antoniou
8a1861d997 w1-gpio: Simplify & get rid of defines
There's no reason to have the OF defines; it complicates the driver.
There's also no need for the funky platform_driver_probe.

Add a few warnings in case there's a failure; helps us find out
what went wrong.

Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-26 16:16:35 -08:00
Pantelis Antoniou
277ed0d542 w1-gpio: Pinctrl-fy
Enable pinctrl for w1-gpio.

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-26 16:16:25 -08:00
Daniel Mack
d2323cf773 onewire: w1-gpio: add ext_pullup_enable pin in platform data
In the process of porting boards to devicetree implemenation, we should
keep information about external circuitry where they belong - the
individual drivers.

This patch adds a way to specify a GPIO to drive the (optional) external
pull-up logic, rather than using a function pointer for that.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Acked-by: Ville Syrjälä <syrjala@sci.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16 10:02:33 -07:00
Daniel Mack
5f3d1382e3 onewire: w1-gpio: add DT bindings
This patch add DT bindings to the w1-gpio driver, along with some
documentation on how to use them.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Acked-by: Ville Syrjälä <syrjala@sci.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16 10:00:23 -07:00
Mark Brown
e250b34e57 w1: Use linux/gpio.h rather than asm/gpio.h
Direct inclusion of the asm header has long been deprecated by the
introduction of gpiolib.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-09 08:36:05 -08:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Daniel Mack
c8a06c1ef0 w1-gpio: add external pull-up enable callback
On embedded devices, sleep mode conditions can be tricky to handle,
Especially when processors tend to pull-down the w1 bus during sleep.  Bus
slaves (such as the ds2760) may interpret this as a reason for power-down
conditions and entirely switch off the device.

This patch adds a callback function pointer to let users switch on and off
the external pull-up resistor.  This lets the outside world know whether
the processor is currently actively driving the bus or not.

When this callback is not provided, the code behaviour won't change.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Acked-by: Ville Syrjala <syrjala@sci.fi>
Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:58 -07:00
Daniel Mack
8d0df7a3d1 drivers/w1/masters/w1-gpio.c: fix read_bit()
W1 master implementations are expected to return 0 or 1 from their
read_bit() function.  However, not all platforms do return these values
from gpio_get_value() - namely PXAs won't.  Hence the w1 gpio-master needs
to break the result down to 0 or 1 itself.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Ville Syrjala <syrjala@sci.fi>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-12 16:20:23 -07:00
Ville Syrjala
ad8dc96e3b w1-gpio: add GPIO w1 bus master driver
Add a GPIO 1-wire bus master driver.  The driver used the GPIO API to
control the wire and the GPIO pin can be specified using platform data
similar to i2c-gpio.  The driver was tested with AT91SAM9260 + DS2401.

Signed-off-by: Ville Syrjala <syrjala@sci.fi>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:41:15 -08:00