linux-toradex.git/drivers/gpio/gpiolib.c, branch v4.4.83

Revert "gpiolib: Split GPIO flags parsing and GPIO configuration"

2016-07-27T16:47:29+00:00

commit 85b03b3033fd4eba82665b3b9902c095a08cc52f upstream.

This reverts commit 923b93e451db876d1479d3e4458fce14fec31d1c.

Make sure consumers do not overwrite gpio flags for pins that have
already been claimed.

While adding support for gpio drivers to refuse a request using
unsupported flags, the order of when the requested flag was checked and
the new flags were applied was reversed to that consumers could
overwrite flags for already requested gpios.

This not only affects device-tree setups where two drivers could request
the same gpio using conflicting configurations, but also allowed user
space to clear gpio flags for already claimed pins simply by attempting
to export them through the sysfs interface. By for example clearing the
FLAG_ACTIVE_LOW flag this way, user space could effectively change the
polarity of a signal.

Reverting this change obviously prevents gpio drivers from doing sanity
checks on the flags in their request callbacks. Fortunately only one
recently added driver (gpio-tps65218 in v4.6) appears to do this, and a
follow up patch could restore this functionality through a different
interface.

Signed-off-by: Johan Hovold 
Signed-off-by: Linus Walleij 
Signed-off-by: Greg Kroah-Hartman

gpio: revert get() to non-errorprogating behaviour

2015-12-17T14:48:29+00:00

commit e20538b82f1f
("gpio: Propagate errors from chip->get()")
started to propagate errors from the .get() functions since
we can get errors from the infrastructure of e.g. slowbus
GPIO expanders.

However it turns out a bunch of drivers relied on the core
to clamp the value, so we need to revert to the old behaviour
and go over all drivers and fix them to conform to the
expectations of the core before we go back to propagating
the error code.

Cc: stable@vger.kernel.org # 4.3+
Cc: Bjorn Andersson 
Cc: Vladimir Zapolskiy 
Fixes: e20538b82f1f ("gpio: Propagate errors from chip->get()")
Reported-by: Michael Trimarchi 
Signed-off-by: Linus Walleij

gpiolib: fix oops, if gpio name is NULL

2015-11-29T21:17:40+00:00

Commit c0017ed71966 ("gpio: Introduce gpio descriptor 'name'") causes
OOPS on boot on LPC32xx boards:

    Unable to handle kernel NULL pointer dereference at virtual address 00000000
    CPU: 0 PID: 1 Comm: swapper Not tainted 4.3.0+ #707
    Hardware name: LPC32XX SoC (Flattened Device Tree)
    task: c381baa0 ti: c381e000 task.ti: c381e000
    PC is at strcmp+0x10/0x40
    LR is at gpiochip_add+0x3d0/0x4d4
    pc : [<>]    lr : [<>]    psr: a0000093
    sp : c381fd60  ip : c381fd70  fp : c381fd6c

    [snip]

    Backtrace:
    [<>] (strcmp) from [<>] (gpiochip_add+0x3d0/0x4d4)
    [<>] (gpiochip_add) from [<>] (lpc32xx_gpio_probe+0x44/0x60)
    [<>] (lpc32xx_gpio_probe) from [<>] (platform_drv_probe+0x40/0x8c)
    [<>] (platform_drv_probe) from [<>] (driver_probe_device+0x110/0x294)
    [<>] (driver_probe_device) from [<>] (__driver_attach+0x70/0x94)
    [<>] (__driver_attach) from [<>] (bus_for_each_dev+0x74/0x98)
    [<>] (bus_for_each_dev) from [<>] (driver_attach+0x20/0x28)
    [<>] (driver_attach) from [<>] (bus_add_driver+0xd4/0x1f0)
    [<>] (bus_add_driver) from [<>] (driver_register+0xa4/0xe8)
    [<>] (driver_register) from [<>] (__platform_driver_register+0x38/0x4c)
    [<>] (__platform_driver_register) from [<>] (lpc32xx_gpio_driver_init+0x18/0x20)
    [<>] (lpc32xx_gpio_driver_init) from [<>] (do_one_initcall+0x108/0x1c8)
    [<>] (do_one_initcall) from [<>] (kernel_init_freeable+0x10c/0x1d4)
    [<>] (kernel_init_freeable) from [<>] (kernel_init+0x10/0xec)
    [<>] (kernel_init) from [<>] (ret_from_fork+0x14/0x24)

This is caused by the fact that at the moment some GPIO names are set
to NULL, there is a hole in linear representation of one GPI bank, see
drivers/gpio/gpio-lpc32xx.c / gpi_p3_names[] for details.

The same problem most probably affects also gpio-cs5535.c, see
cs5535_gpio_names[].

Signed-off-by: Vladimir Zapolskiy 
Signed-off-by: Linus Walleij

Merge tag 'pm+acpi-4.4-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2015-11-05T02:10:13+00:00

Pull power management and ACPI updates from Rafael Wysocki:
"Quite a new features are included this time.

First off, the Collaborative Processor Performance Control interface
(version 2) defined by ACPI will now be supported on ARM64 along with
a cpufreq frontend for CPU performance scaling.

Second, ACPI gets a new infrastructure for the early probing of IRQ
chips and clock sources (along the lines of the existing similar
mechanism for DT).

Next, the ACPI core and the generic device properties API will now
support a recently introduced hierarchical properties extension of the
_DSD (Device Specific Data) ACPI device configuration object. If the
ACPI platform firmware uses that extension to organize device
properties in a hierarchical way, the kernel will automatically handle
it and make those properties available to device drivers via the
generic device properties API.

It also will be possible to build the ACPICA's AML interpreter
debugger into the kernel now and use that to diagnose AML-related
problems more efficiently. In the future, this should make it
possible to single-step AML execution and do similar things.
Interesting stuff, although somewhat experimental at this point.

Finally, the PM core gets a new mechanism that can be used by device
drivers to distinguish between suspend-to-RAM (based on platform
firmware support) and suspend-to-idle (or other variants of system
suspend the platform firmware is not involved in) and possibly
optimize their device suspend/resume handling accordingly.

In addition to that, some existing features are re-organized quite
substantially.

First, the ACPI-based handling of PCI host bridges on x86 and ia64 is
unified and the common code goes into the ACPI core (so as to reduce
code duplication and eliminate non-essential differences between the
two architectures in that area).

Second, the Operating Performance Points (OPP) framework is
reorganized to make the code easier to find and follow.

Next, the cpufreq core's sysfs interface is reorganized to get rid of
the "primary CPU" concept for configurations in which the same
performance scaling settings are shared between multiple CPUs.

Finally, some interfaces that aren't necessary any more are dropped
from the generic power domains framework.

On top of the above we have some minor extensions, cleanups and bug
fixes in multiple places, as usual.

Specifics:

- ACPICA update to upstream revision 20150930 (Bob Moore, Lv Zheng).

The most significant change is to allow the AML debugger to be
built into the kernel. On top of that there is an update related
to the NFIT table (the ACPI persistent memory interface) and a few
fixes and cleanups.

- ACPI CPPC2 (Collaborative Processor Performance Control v2) support
along with a cpufreq frontend (Ashwin Chaugule).

This can only be enabled on ARM64 at this point.

- New ACPI infrastructure for the early probing of IRQ chips and
clock sources (Marc Zyngier).

- Support for a new hierarchical properties extension of the ACPI
_DSD (Device Specific Data) device configuration object allowing
the kernel to handle hierarchical properties (provided by the
platform firmware this way) automatically and make them available
to device drivers via the generic device properties interface
(Rafael Wysocki).

- Generic device properties API extension to obtain an index of
certain string value in an array of strings, along the lines of
of_property_match_string(), but working for all of the supported
firmware node types, and support for the "dma-names" device
property based on it (Mika Westerberg).

- ACPI core fix to parse the MADT (Multiple APIC Description Table)
entries in the order expected by platform firmware (and mandated by
the specification) to avoid confusion on systems with more than 255
logical CPUs (Lukasz Anaczkowski).

- Consolidation of the ACPI-based handling of PCI host bridges on x86
and ia64 (Jiang Liu).

- ACPI core fixes to ensure that the correct IRQ number is used to
represent the SCI (System Control Interrupt) in the cases when it
has been re-mapped (Chen Yu).

- New ACPI backlight quirk for Lenovo IdeaPad S405 (Hans de Goede).

- ACPI EC driver fixes (Lv Zheng).

- Assorted ACPI fixes and cleanups (Dan Carpenter, Insu Yun, Jiri
Kosina, Rami Rosen, Rasmus Villemoes).

- New mechanism in the PM core allowing drivers to check if the
platform firmware is going to be involved in the upcoming system
suspend or if it has been involved in the suspend the system is
resuming from at the moment (Rafael Wysocki).

This should allow drivers to optimize their suspend/resume handling
in some cases and the changes include a couple of users of it (the
i8042 input driver, PCI PM).

- PCI PM fix to prevent runtime-suspended devices with PME enabled
from being resumed during system suspend even if they aren't
configured to wake up the system from sleep (Rafael Wysocki).

- New mechanism to report the number of a wakeup IRQ that woke up the
system from sleep last time (Alexandra Yates).

- Removal of unused interfaces from the generic power domains
framework and fixes related to latency measurements in that code
(Ulf Hansson, Daniel Lezcano).

- cpufreq core sysfs interface rework to make it handle CPUs that
share performance scaling settings (represented by a common cpufreq
policy object) more symmetrically (Viresh Kumar).

This should help to simplify the CPU offline/online handling among
other things.

- cpufreq core fixes and cleanups (Viresh Kumar).

- intel_pstate fixes related to the Turbo Activation Ratio (TAR)
mechanism on client platforms which causes the turbo P-states range
to vary depending on platform firmware settings (Srinivas
Pandruvada).

- intel_pstate sysfs interface fix (Prarit Bhargava).

- Assorted cpufreq driver (imx, tegra20, powernv, integrator) fixes
and cleanups (Bai Ping, Bartlomiej Zolnierkiewicz, Shilpasri G
Bhat, Luis de Bethencourt).

- cpuidle mvebu driver cleanups (Russell King).

- OPP (Operating Performance Points) framework code reorganization to
make it more maintainable (Viresh Kumar).

- Intel Broxton support for the RAPL (Running Average Power Limits)
power capping driver (Amy Wiles).

- Assorted power management code fixes and cleanups (Dan Carpenter,
Geert Uytterhoeven, Geliang Tang, Luis de Bethencourt, Rasmus
Villemoes)"

* tag 'pm+acpi-4.4-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (108 commits)
cpufreq: postfix policy directory with the first CPU in related_cpus
cpufreq: create cpu/cpufreq/policyX directories
cpufreq: remove cpufreq_sysfs_{create|remove}_file()
cpufreq: create cpu/cpufreq at boot time
cpufreq: Use cpumask_copy instead of cpumask_or to copy a mask
cpufreq: ondemand: Drop unnecessary locks from update_sampling_rate()
PM / Domains: Merge measurements for PM QoS device latencies
PM / Domains: Don't measure ->start|stop() latency in system PM callbacks
PM / clk: Fix broken build due to non-matching code and header #ifdefs
ACPI / Documentation: add copy_dsdt to ACPI format options
ACPI / sysfs: correctly check failing memory allocation
ACPI / video: Add a quirk to force native backlight on Lenovo IdeaPad S405
ACPI / CPPC: Fix potential memory leak
ACPI / CPPC: signedness bug in register_pcc_channel()
ACPI / PAD: power_saving_thread() is not freezable
ACPI / PM: Fix incorrect wakeup IRQ setting during suspend-to-idle
ACPI: Using correct irq when waiting for events
ACPI: Use correct IRQ when uninstalling ACPI interrupt handler
cpuidle: mvebu: disable the bind/unbind attributes and use builtin_platform_driver
cpuidle: mvebu: clean up multiple platform drivers
...

Merge branch 'device-properties'

2015-10-25T21:51:48+00:00

* device-properties:
  ACPI / property: Fix subnode lookup scope for data-only subnodes
  acpi-dma: Add support for "dma-names" device property
  device property: Add fwnode_property_match_string()
  ACPI / property: Extend device_get_next_child_node() to data-only nodes
  ACPI / gpio: Split acpi_get_gpiod_by_index()
  ACPI / property: Extend fwnode_property_* to data-only subnodes
  ACPI / property: Expose data-only subnodes via sysfs
  ACPI / property: Add support for data-only subnodes
  ACPI / property: Add routine for extraction of _DSD properties

gpiolib: Add and use OF_GPIO_SINGLE_ENDED flag

2015-10-16T20:49:26+00:00

The flag matches the DT GPIO_SINGLE_ENDED flag and allows drivers to
parse and use the DT flag to handle single-ended (open-drain or
open-source) GPIOs.

Signed-off-by: Laurent Pinchart 
Signed-off-by: Linus Walleij

gpiolib: Split GPIO flags parsing and GPIO configuration

2015-10-16T20:46:46+00:00

When requesting a GPIO through the legacy or the gpiod_* API the
gpiochip request operation is first called and then the GPIO flags are
parsed and the GPIO is configured. This prevents the gpiochip from
rejecting the request if the flags are not supported by the device.

To fix this split the parse-and-configure operation in two and parse
flags before requesting the GPIO.

Signed-off-by: Laurent Pinchart 
Signed-off-by: Linus Walleij

gpiolib: provide generic request/free implementations

2015-10-16T20:11:16+00:00

Provide generic request/free implementations that pinctrl aware gpio
drivers can use instead of open coding if they use a 1:1 pin to gpio
signal mapping.

Signed-off-by: Jonas Gorski 
Signed-off-by: Linus Walleij

gpio: gpiolib: don't compare an unsigned for >= 0

2015-10-02T11:19:35+00:00

The parameter offset is an unsigned, so it makes no sense to compare
it for >= 0. Fix the compiler warning regarding this by removing this
comparison.

As the macro GPIO_OFFSET_VALID is only used at this single place, simplify
the code by dropping the macro completely and dropping the invert, too.

No functional change.

Signed-off-by: Dirk Behme 
Acked-by: Alexandre Courbot 
Signed-off-by: Linus Walleij

gpio: keep the GPIO line names internal

2015-09-24T17:48:53+00:00

This refactors the changes to the GPIO line naming mechanism to
not have so widespread effects, instead we conclude the patch series
by having created a name attribute in the GPIO descriptor, that need
not be globally unique, and it will be initialized from the old
.names array in struct gpio_chip if it exists, then used in the legacy
sysfs code like the array was used previously.

The associated changes to name lines from the device tree are
controversial and need to stand alone from this. Resulting changes:

1. Remove the export and the header for the gpio_name_to_desc() as so
far the only use is inside gpiolib.c. Staticize gpio_name_to_desc()
and move it above the only function using it.

2. Only print a warning if there are two GPIO lines with the same name.
The reason is to preserve current behaviour: before the previous
changes to the naming mechanism this would not reject probing the
driver, instead the error would occur when trying to export the line
in sysfs, so restore this behaviour, but print a friendly warning
if names collide.

Cc: Johan Hovold 
Cc: Markus Pargmann 
Signed-off-by: Linus Walleij