Certain I2C based GPIO expanders could be used in sleepable context,
this results in:
[  115.890569] ------------[ cut here ]------------
[  115.895422] WARNING: CPU: 0 PID: 1115 at drivers/gpio/gpiolib.c:1370 gpiod_set_raw_value+0x40/0x4c()
[  115.905024] Modules linked in:
[  115.908229] CPU: 0 PID: 1115 Comm: sh Tainted: G        W      3.18.0-rc7-next-20141203-dirty #1
[  115.917461] Hardware name: Generic DRA74X (Flattened Device Tree)
[  115.923876] [<c0015368>] (unwind_backtrace) from [<c00119f4>] (show_stack+0x10/0x14)
[  115.932013] [<c00119f4>] (show_stack) from [<c05b78e8>] (dump_stack+0x78/0x94)
[  115.939594] [<c05b78e8>] (dump_stack) from [<c003de28>] (warn_slowpath_common+0x7c/0xb4)
[  115.948094] [<c003de28>] (warn_slowpath_common) from [<c003de7c>] (warn_slowpath_null+0x1c/0x24)
[  115.957315] [<c003de7c>] (warn_slowpath_null) from [<c03461e8>] (gpiod_set_raw_value+0x40/0x4c)
[  115.966457] [<c03461e8>] (gpiod_set_raw_value) from [<c04866f4>] (set_fan_speed+0x4c/0x64)
[  115.975145] [<c04866f4>] (set_fan_speed) from [<c04868a8>] (set_rpm+0x98/0xac)
[  115.982742] [<c04868a8>] (set_rpm) from [<c039fb4c>] (dev_attr_store+0x18/0x24)
[  115.990426] [<c039fb4c>] (dev_attr_store) from [<c01b0a28>] (sysfs_kf_write+0x4c/0x50)
[  115.998742] [<c01b0a28>] (sysfs_kf_write) from [<c01afe1c>] (kernfs_fop_write+0xbc/0x19c)
[  116.007333] [<c01afe1c>] (kernfs_fop_write) from [<c0148cc4>] (vfs_write+0xb0/0x1a0)
[  116.015461] [<c0148cc4>] (vfs_write) from [<c0148fbc>] (SyS_write+0x44/0x84)
[  116.022881] [<c0148fbc>] (SyS_write) from [<c000e5c0>] (ret_fast_syscall+0x0/0x48)
[  116.030833] ---[ end trace 3a0b636123acab82 ]---

So, switch over to sleepable GPIO operations as there is no mandatory
need for non-sleepable gpio operations in the fan driver.

This allows the fan driver to be used with i2c based gpio expanders such
as palmas_gpio.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

On platforms with sizeof(int) < sizeof(unsigned long), writing a rpm value
larger than MAXINT will result in unpredictable limit values written to the
chip. Avoid auto-conversion from unsigned long to int to fix the problem.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Cc: stable@vger.kernel.org
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

This simplifies the code a bit and also ensures the attribute groups are
properly removed from sysfs when unload the module.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Since commit 648cd48c
The hwmon name attributes must not include '-' so the name must be
rename from gpio-fan to gpio_fan
Signed-off-by: NJulien D'Ascenzio <jdascenzio@yahoo.fr>
Reviewed-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Make of_device_id array const, because all OF functions
handle it as const.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

'of_match_ptr' is defined in linux/of.h. Include it explicitly.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

get_fan_speed_index() returns -EINVAL in case of errors, only to have it
ignored and replaced with -ENODEV. Make it return -ENODEV and use it.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Simplify code and reduce object size by more than 300 bytes (x86_64).

Cc: Jamie Lentin <jm@lentin.co.uk>
Cc: Simon Guinot <simon.guinot@sequanux.org>
Tested-by: NSimon Guinot <simon.guinot@sequanux.org>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Fix:

ERROR: Macros with complex values should be enclosed in parenthesis

when it is seen due to complex code and not due to multi-line variable
declarations.

Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Alistair John Strachan <alistair@devzero.co.uk>
Acked-by: NAlistair John Strachan <alistair@devzero.co.uk>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

This patch replaces the horribly coded of_count_named_gpios() with a
call to of_count_phandle_with_args() which is far more efficient. This
also changes the return value of of_gpio_count() & of_gpio_named_count()
from 'unsigned int' to 'int' so that it can return an error code. All
the users of that function are fixed up to correctly handle a negative
return value.

v2: Split GPIO portion into a separate patch
Tested-by: NAndreas Larsson <andreas@gaisler.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>

CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Alistair John Strachan <alistair@devzero.co.uk>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Juerg Haefliger <juergh@gmail.com>
Cc: Andreas Herrmann <herrmann.der.user@googlemail.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Rudolf Marek <r.marek@assembler.cz>
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: "Mark M. Hoffman" <mhoffman@lightlink.com>
Cc: Roger Lucas <vt8231@hiddenengine.co.uk>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CONFIG_HOTPLUG is going away as an option so __devinitdata is no
longer needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Jean Delvare <khali@linux-fr.org>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Alistair John Strachan <alistair@devzero.co.uk>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Juerg Haefliger <juergh@gmail.com>
Cc: Andreas Herrmann <herrmann.der.user@googlemail.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Rudolf Marek <r.marek@assembler.cz>
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: "Mark M. Hoffman" <mhoffman@lightlink.com>
Cc: Roger Lucas <vt8231@hiddenengine.co.uk>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Alistair John Strachan <alistair@devzero.co.uk>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Juerg Haefliger <juergh@gmail.com>
Cc: Andreas Herrmann <herrmann.der.user@googlemail.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Rudolf Marek <r.marek@assembler.cz>
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: "Mark M. Hoffman" <mhoffman@lightlink.com>
Cc: Roger Lucas <vt8231@hiddenengine.co.uk>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The following fixes build errors on sparc. Without any DT support,
of_match_ptr is NULL and the below is a no-op. However, if just
CONFIG_OF is defined then so is of_match_ptr.

All useful parts of the gpio-fan DT support rely on CONFIG_OF_GPIO
anyway, so of_match_table should too.
Signed-off-by: NJamie Lentin <jm@lentin.co.uk>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Allow a gpio-fan to be defined in devicetree, see binding documentation
for details.
Signed-off-by: NJamie Lentin <jm@lentin.co.uk>
Acked-by: NAndrew Lunn <andrew@lunn.ch>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NJason Cooper <jason@lakedaemon.net>

Make the gpio-fan driver define its PM callbacks through
a struct dev_pm_ops object rather than by using legacy PM hooks
in struct platform_driver.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
[linux@roeck-us.net: CONFIG_PM->CONFIG_PM_SLEEP, and remove unnecessary ()]
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Convert to use devm_ functions to reduce code size and simplify the code.

Cc: Simon Guinot <sguinot@lacie.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Acked-by: NSimon Guinot <sguinot@lacie.com>

replaced strict_strtol with kstrtol and
replaced strict_strtuol with kstrtuol

This satisfies checkpatch -f
Compile tested only: no warnings or errors given
Signed-off-by: NFrans Meulenbroeks <fransmeulenbroeks@gmail.com>
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>

This patch converts the drivers in drivers/hwmon/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Cc: Donggeun Kim <dg77.kim@samsung.com>
Cc: Simon Guinot <sguinot@lacie.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Ben Dooks <ben@simtec.co.uk>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: J Keerthy <j-keerthy@ti.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>

Scripted with coccinelle.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

In current implementation, the sysfs entries is not removed before return -ENODEV.

Creating the sysfs attribute should be the last thing done by the function,
after all the rest has been successful.
Otherwise there is a small window during which user-space can access the attribute
but the driver isn't ready to deal with the requests.

Fix it by moving sysfs_create_group to be the last thing done by the function.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NSimon Guinot <sguinot@lacie.com>
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>

This patch adds hwmon support for fans connected to GPIO lines.

Platform specific information such as GPIO pinout and speed conversion array
(rpm from/to GPIO value) are passed to the driver via platform_data.
Signed-off-by: NSimon Guinot <sguinot@lacie.com>
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>