Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6:
  regulator: fix kernel-doc warnings
  regulator: catch some registration errors
  regulator: Add basic DocBook manual
  regulator: Fix some kerneldoc rendering issues
  regulator: Add missing kerneldoc
  regulator: Clean up kerneldoc warnings
  regulator: Remove extraneous kerneldoc annotations
  regulator: init/link earlier
  regulator: move set_machine_constraints after regulator device initialization
  regulator: da903x: make da903x_is_enabled return 0 or 1
  regulator: da903x: add '\n' to error messages
  regulator: sysfs attribute reduction (v2)
  regulator: code shrink (v2)
  regulator: improved mode error checks
  regulator: enable/disable refcounting
  regulator: struct device - replace bus_id with dev_name(), dev_set_name()

9 files changed, 746 insertions, 272 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-regulator b/Documentation/ABI/testing/sysfs-class-regulator
index 3731f6f29bc..873ef1fc156 100644
--- a/Documentation/ABI/testing/sysfs-class-regulator
+++ b/Documentation/ABI/testing/sysfs-class-regulator
@@ -3,8 +3,9 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
-		state. This holds the regulator output state.
+		Some regulator directories will contain a field called
+		state. This reports the regulator enable status, for
+		regulators which can report that value.
 
 		This will be one of the following strings:
 
@@ -18,7 +19,8 @@ Description:
 		'disabled' means the regulator output is OFF and is not
 		supplying power to the system..
 
-		'unknown' means software cannot determine the state.
+		'unknown' means software cannot determine the state, or
+		the reported state is invalid.
 
 		NOTE: this field can be used in conjunction with microvolts
 		and microamps to determine regulator output levels.
@@ -53,9 +55,10 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		microvolts. This holds the regulator output voltage setting
-		measured in microvolts (i.e. E-6 Volts).
+		measured in microvolts (i.e. E-6 Volts), for regulators
+		which can report that voltage.
 
 		NOTE: This value should not be used to determine the regulator
 		output voltage level as this value is the same regardless of
@@ -67,9 +70,10 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		microamps. This holds the regulator output current limit
-		setting measured in microamps (i.e. E-6 Amps).
+		setting measured in microamps (i.e. E-6 Amps), for regulators
+		which can report that current.
 
 		NOTE: This value should not be used to determine the regulator
 		output current level as this value is the same regardless of
@@ -81,8 +85,9 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
-		opmode. This holds the regulator operating mode setting.
+		Some regulator directories will contain a field called
+		opmode. This holds the current regulator operating mode,
+		for regulators which can report it.
 
 		The opmode value can be one of the following strings:
 
@@ -92,7 +97,7 @@ Description:
 		'standby'
 		'unknown'
 
-		The modes are described in include/linux/regulator/regulator.h
+		The modes are described in include/linux/regulator/consumer.h
 
 		NOTE: This value should not be used to determine the regulator
 		output operating mode as this value is the same regardless of
@@ -104,9 +109,10 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		min_microvolts. This holds the minimum safe working regulator
-		output voltage setting for this domain measured in microvolts.
+		output voltage setting for this domain measured in microvolts,
+		for regulators which support voltage constraints.
 
 		NOTE: this will return the string 'constraint not defined' if
 		the power domain has no min microvolts constraint defined by
@@ -118,9 +124,10 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		max_microvolts. This holds the maximum safe working regulator
-		output voltage setting for this domain measured in microvolts.
+		output voltage setting for this domain measured in microvolts,
+		for regulators which support voltage constraints.
 
 		NOTE: this will return the string 'constraint not defined' if
 		the power domain has no max microvolts constraint defined by
@@ -132,10 +139,10 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		min_microamps. This holds the minimum safe working regulator
 		output current limit setting for this domain measured in
-		microamps.
+		microamps, for regulators which support current constraints.
 
 		NOTE: this will return the string 'constraint not defined' if
 		the power domain has no min microamps constraint defined by
@@ -147,10 +154,10 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		max_microamps. This holds the maximum safe working regulator
 		output current limit setting for this domain measured in
-		microamps.
+		microamps, for regulators which support current constraints.
 
 		NOTE: this will return the string 'constraint not defined' if
 		the power domain has no max microamps constraint defined by
@@ -185,7 +192,7 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		requested_microamps. This holds the total requested load
 		current in microamps for this regulator from all its consumer
 		devices.
@@ -204,125 +211,102 @@ Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_mem_microvolts. This holds the regulator output
 		voltage setting for this domain measured in microvolts when
-		the system is suspended to memory.
-
-		NOTE: this will return the string 'not defined' if
-		the power domain has no suspend to memory voltage defined by
-		platform code.
+		the system is suspended to memory, for voltage regulators
+		implementing suspend voltage configuration constraints.
 
 What:		/sys/class/regulator/.../suspend_disk_microvolts
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_disk_microvolts. This holds the regulator output
 		voltage setting for this domain measured in microvolts when
-		the system is suspended to disk.
-
-		NOTE: this will return the string 'not defined' if
-		the power domain has no suspend to disk voltage defined by
-		platform code.
+		the system is suspended to disk, for voltage regulators
+		implementing suspend voltage configuration constraints.
 
 What:		/sys/class/regulator/.../suspend_standby_microvolts
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_standby_microvolts. This holds the regulator output
 		voltage setting for this domain measured in microvolts when
-		the system is suspended to standby.
-
-		NOTE: this will return the string 'not defined' if
-		the power domain has no suspend to standby voltage defined by
-		platform code.
+		the system is suspended to standby, for voltage regulators
+		implementing suspend voltage configuration constraints.
 
 What:		/sys/class/regulator/.../suspend_mem_mode
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_mem_mode. This holds the regulator operating mode
 		setting for this domain when the system is suspended to
-		memory.
-
-		NOTE: this will return the string 'not defined' if
-		the power domain has no suspend to memory mode defined by
-		platform code.
+		memory, for regulators implementing suspend mode
+		configuration constraints.
 
 What:		/sys/class/regulator/.../suspend_disk_mode
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_disk_mode. This holds the regulator operating mode
-		setting for this domain when the system is suspended to disk.
-
-		NOTE: this will return the string 'not defined' if
-		the power domain has no suspend to disk mode defined by
-		platform code.
+		setting for this domain when the system is suspended to disk,
+		for regulators implementing suspend mode configuration
+		constraints.
 
 What:		/sys/class/regulator/.../suspend_standby_mode
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_standby_mode. This holds the regulator operating mode
 		setting for this domain when the system is suspended to
-		standby.
-
-		NOTE: this will return the string 'not defined' if
-		the power domain has no suspend to standby mode defined by
-		platform code.
+		standby, for regulators implementing suspend mode
+		configuration constraints.
 
 What:		/sys/class/regulator/.../suspend_mem_state
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_mem_state. This holds the regulator operating state
-		when suspended to memory.
-
-		This will be one of the following strings:
+		when suspended to memory, for regulators implementing suspend
+		configuration constraints.
 
-		'enabled'
-		'disabled'
-		'not defined'
+		This will be one of the same strings reported by
+		the "state" attribute.
 
 What:		/sys/class/regulator/.../suspend_disk_state
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_disk_state. This holds the regulator operating state
-		when suspended to disk.
-
-		This will be one of the following strings:
+		when suspended to disk, for regulators implementing
+		suspend configuration constraints.
 
-		'enabled'
-		'disabled'
-		'not defined'
+		This will be one of the same strings reported by
+		the "state" attribute.
 
 What:		/sys/class/regulator/.../suspend_standby_state
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_standby_state. This holds the regulator operating
-		state when suspended to standby.
-
-		This will be one of the following strings:
+		state when suspended to standby, for regulators implementing
+		suspend configuration constraints.
 
-		'enabled'
-		'disabled'
-		'not defined'
+		This will be one of the same strings reported by
+		the "state" attribute.
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index 0a08126d309..dc3154e4927 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -12,7 +12,7 @@ DOCBOOKS := z8530book.xml mcabook.xml \
 	    kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
 	    gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
 	    genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml \
-	    mac80211.xml debugobjects.xml sh.xml
+	    mac80211.xml debugobjects.xml sh.xml regulator.xml
 
 ###
 # The build process is as follows (targets):
diff --git a/Documentation/DocBook/regulator.tmpl b/Documentation/DocBook/regulator.tmpl
new file mode 100644
index 00000000000..53f4f8d3b81
--- /dev/null
+++ b/Documentation/DocBook/regulator.tmpl
@@ -0,0 +1,304 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
+	"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
+
+<book id="regulator-api">
+ <bookinfo>
+  <title>Voltage and current regulator API</title>
+
+  <authorgroup>
+   <author>
+    <firstname>Liam</firstname>
+    <surname>Girdwood</surname>
+    <affiliation>
+     <address>
+      <email>lrg@slimlogic.co.uk</email>
+     </address>
+    </affiliation>
+   </author>
+   <author>
+    <firstname>Mark</firstname>
+    <surname>Brown</surname>
+    <affiliation>
+     <orgname>Wolfson Microelectronics</orgname>
+     <address>
+      <email>broonie@opensource.wolfsonmicro.com</email>
+     </address>
+    </affiliation>
+   </author>
+  </authorgroup>
+
+  <copyright>
+   <year>2007-2008</year>
+   <holder>Wolfson Microelectronics</holder>
+  </copyright>
+  <copyright>
+   <year>2008</year>
+   <holder>Liam Girdwood</holder>
+  </copyright>
+
+  <legalnotice>
+   <para>
+     This documentation is free software; you can redistribute
+     it and/or modify it under the terms of the GNU General Public
+     License version 2 as published by the Free Software Foundation.
+   </para>
+
+   <para>
+     This program is distributed in the hope that it will be
+     useful, but WITHOUT ANY WARRANTY; without even the implied
+     warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+     See the GNU General Public License for more details.
+   </para>
+
+   <para>
+     You should have received a copy of the GNU General Public
+     License along with this program; if not, write to the Free
+     Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+     MA 02111-1307 USA
+   </para>
+
+   <para>
+     For more details see the file COPYING in the source
+     distribution of Linux.
+   </para>
+  </legalnotice>
+ </bookinfo>
+
+<toc></toc>
+
+  <chapter id="intro">
+    <title>Introduction</title>
+    <para>
+	This framework is designed to provide a standard kernel
+	interface to control voltage and current regulators.
+    </para>
+    <para>
+	The intention is to allow systems to dynamically control
+	regulator power output in order to save power and prolong
+	battery life.  This applies to both voltage regulators (where
+	voltage output is controllable) and current sinks (where current
+	limit is controllable).
+    </para>
+    <para>
+	Note that additional (and currently more complete) documentation
+	is available in the Linux kernel source under
+	<filename>Documentation/power/regulator</filename>.
+    </para>
+
+    <sect1 id="glossary">
+       <title>Glossary</title>
+       <para>
+	The regulator API uses a number of terms which may not be
+	familiar:
+       </para>
+       <glossary>
+
+         <glossentry>
+	   <glossterm>Regulator</glossterm>
+	   <glossdef>
+	     <para>
+	Electronic device that supplies power to other devices.  Most
+	regulators can enable and disable their output and some can also
+	control their output voltage or current.
+	     </para>
+	   </glossdef>
+         </glossentry>
+
+	 <glossentry>
+	   <glossterm>Consumer</glossterm>
+	   <glossdef>
+	     <para>
+	Electronic device which consumes power provided by a regulator.
+	These may either be static, requiring only a fixed supply, or
+	dynamic, requiring active management of the regulator at
+	runtime.
+	     </para>
+	   </glossdef>
+	 </glossentry>
+
+	 <glossentry>
+	   <glossterm>Power Domain</glossterm>
+	   <glossdef>
+	     <para>
+	The electronic circuit supplied by a given regulator, including
+	the regulator and all consumer devices.  The configuration of
+	the regulator is shared between all the components in the
+	circuit.
+	     </para>
+	   </glossdef>
+	 </glossentry>
+
+	 <glossentry>
+	   <glossterm>Power Management Integrated Circuit</glossterm>
+	   <acronym>PMIC</acronym>
+	   <glossdef>
+	     <para>
+	An IC which contains numerous regulators and often also other
+	subsystems.  In an embedded system the primary PMIC is often
+	equivalent to a combination of the PSU and southbridge in a
+	desktop system.
+	     </para>
+	   </glossdef>
+	 </glossentry>
+	</glossary>
+     </sect1>
+  </chapter>
+
+  <chapter id="consumer">
+     <title>Consumer driver interface</title>
+     <para>
+       This offers a similar API to the kernel clock framework.
+       Consumer drivers use <link
+       linkend='API-regulator-get'>get</link> and <link
+       linkend='API-regulator-put'>put</link> operations to acquire and
+       release regulators.  Functions are
+       provided to <link linkend='API-regulator-enable'>enable</link>
+       and <link linkend='API-regulator-disable'>disable</link> the
+       reguator and to get and set the runtime parameters of the
+       regulator.
+     </para>
+     <para>
+       When requesting regulators consumers use symbolic names for their
+       supplies, such as "Vcc", which are mapped into actual regulator
+       devices by the machine interface.
+     </para>
+     <para>
+	A stub version of this API is provided when the regulator
+	framework is not in use in order to minimise the need to use
+	ifdefs.
+     </para>
+
+     <sect1 id="consumer-enable">
+       <title>Enabling and disabling</title>
+       <para>
+         The regulator API provides reference counted enabling and
+	 disabling of regulators. Consumer devices use the <function><link
+	 linkend='API-regulator-enable'>regulator_enable</link></function>
+	 and <function><link
+	 linkend='API-regulator-disable'>regulator_disable</link>
+	 </function> functions to enable and disable regulators.  Calls
+	 to the two functions must be balanced.
+       </para>
+       <para>
+         Note that since multiple consumers may be using a regulator and
+	 machine constraints may not allow the regulator to be disabled
+	 there is no guarantee that calling
+	 <function>regulator_disable</function> will actually cause the
+	 supply provided by the regulator to be disabled. Consumer
+	 drivers should assume that the regulator may be enabled at all
+	 times.
+       </para>
+     </sect1>
+
+     <sect1 id="consumer-config">
+       <title>Configuration</title>
+       <para>
+         Some consumer devices may need to be able to dynamically
+	 configure their supplies.  For example, MMC drivers may need to
+	 select the correct operating voltage for their cards.  This may
+	 be done while the regulator is enabled or disabled.
+       </para>
+       <para>
+	 The <function><link
+	 linkend='API-regulator-set-voltage'>regulator_set_voltage</link>
+	 </function> and <function><link
+	 linkend='API-regulator-set-current-limit'
+	 >regulator_set_current_limit</link>
+	 </function> functions provide the primary interface for this.
+	 Both take ranges of voltages and currents, supporting drivers
+	 that do not require a specific value (eg, CPU frequency scaling
+	 normally permits the CPU to use a wider range of supply
+	 voltages at lower frequencies but does not require that the
+	 supply voltage be lowered).  Where an exact value is required
+	 both minimum and maximum values should be identical.
+       </para>
+     </sect1>
+
+     <sect1 id="consumer-callback">
+       <title>Callbacks</title>
+       <para>
+	  Callbacks may also be <link
+	  linkend='API-regulator-register-notifier'>registered</link>
+	  for events such as regulation failures.
+       </para>
+     </sect1>
+   </chapter>
+
+   <chapter id="driver">
+     <title>Regulator driver interface</title>
+     <para>
+       Drivers for regulator chips <link
+       linkend='API-regulator-register'>register</link> the regulators
+       with the regulator core, providing operations structures to the
+       core.  A <link
+       linkend='API-regulator-notifier-call-chain'>notifier</link> interface
+       allows error conditions to be reported to the core.
+     </para>
+     <para>
+       Registration should be triggered by explicit setup done by the
+       platform, supplying a <link
+       linkend='API-struct-regulator-init-data'>struct
+       regulator_init_data</link> for the regulator containing
+       <link linkend='machine-constraint'>constraint</link> and
+       <link linkend='machine-supply'>supply</link> information.
+     </para>
+   </chapter>
+
+   <chapter id="machine">
+     <title>Machine interface</title>
+     <para>
+       This interface provides a way to define how regulators are
+       connected to consumers on a given system and what the valid
+       operating parameters are for the system.
+     </para>
+
+     <sect1 id="machine-supply">
+       <title>Supplies</title>
+       <para>
+         Regulator supplies are specified using <link
+	 linkend='API-struct-regulator-consumer-supply'>struct
+	 regulator_consumer_supply</link>.  This is done at
+	 <link linkend='driver'>driver registration
+	 time</link> as part of the machine constraints.
+       </para>
+     </sect1>
+
+     <sect1 id="machine-constraint">
+       <title>Constraints</title>
+       <para>
+	 As well as definining the connections the machine interface
+	 also provides constraints definining the operations that
+	 clients are allowed to perform and the parameters that may be
+	 set.  This is required since generally regulator devices will
+	 offer more flexibility than it is safe to use on a given
+	 system, for example supporting higher supply voltages than the
+	 consumers are rated for.
+       </para>
+       <para>
+	 This is done at <link linkend='driver'>driver
+	 registration time</link> by providing a <link
+	 linkend='API-struct-regulation-constraints'>struct
+	 regulation_constraints</link>.
+       </para>
+       <para>
+         The constraints may also specify an initial configuration for the
+         regulator in the constraints, which is particularly useful for
+         use with static consumers.
+       </para>
+     </sect1>
+  </chapter>
+
+  <chapter id="api">
+    <title>API reference</title>
+    <para>
+      Due to limitations of the kernel documentation framework and the
+      existing layout of the source code the entire regulator API is
+      documented here.
+    </para>
+!Iinclude/linux/regulator/consumer.h
+!Iinclude/linux/regulator/machine.h
+!Iinclude/linux/regulator/driver.h
+!Edrivers/regulator/core.c
+  </chapter>
+</book>
diff --git a/drivers/Makefile b/drivers/Makefile
index e121b66ef08..6326f4dbbda 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -18,6 +18,9 @@ obj-$(CONFIG_ARM_AMBA)		+= amba/
 
 obj-$(CONFIG_XEN)		+= xen/
 
+# regulators early, since some subsystems rely on them to initialize
+obj-$(CONFIG_REGULATOR)		+= regulator/
+
 # char/ comes before serial/ etc so that the VT console is the boot-time
 # default.
 obj-y				+= char/
@@ -101,5 +104,4 @@ obj-$(CONFIG_PPC_PS3)		+= ps3/
 obj-$(CONFIG_OF)		+= of/
 obj-$(CONFIG_SSB)		+= ssb/
 obj-$(CONFIG_VIRTIO)		+= virtio/
-obj-$(CONFIG_REGULATOR)		+= regulator/
 obj-$(CONFIG_STAGING)		+= staging/
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 02a774424e8..f511a406fca 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -29,7 +29,7 @@ static DEFINE_MUTEX(regulator_list_mutex);
 static LIST_HEAD(regulator_list);
 static LIST_HEAD(regulator_map_list);
 
-/**
+/*
  * struct regulator_dev
  *
  * Voltage / Current regulator class device. One for each regulator.
@@ -56,7 +56,7 @@ struct regulator_dev {
 	void *reg_data;		/* regulator_dev data */
 };
 
-/**
+/*
  * struct regulator_map
  *
  * Used to provide symbolic supply names to devices.
@@ -79,7 +79,7 @@ struct regulator {
 	int uA_load;
 	int min_uV;
 	int max_uV;
-	int enabled; /* client has called enabled */
+	int enabled; /* count of client enables */
 	char *supply_name;
 	struct device_attribute dev_attr;
 	struct regulator_dev *rdev;
@@ -174,6 +174,16 @@ static int regulator_check_current_limit(struct regulator_dev *rdev,
 /* operating mode constraint check */
 static int regulator_check_mode(struct regulator_dev *rdev, int mode)
 {
+	switch (mode) {
+	case REGULATOR_MODE_FAST:
+	case REGULATOR_MODE_NORMAL:
+	case REGULATOR_MODE_IDLE:
+	case REGULATOR_MODE_STANDBY:
+		break;
+	default:
+		return -EINVAL;
+	}
+
 	if (!rdev->constraints) {
 		printk(KERN_ERR "%s: no constraints for %s\n", __func__,
 		       rdev->desc->name);
@@ -232,6 +242,7 @@ static ssize_t regulator_uV_show(struct device *dev,
 
 	return ret;
 }
+static DEVICE_ATTR(microvolts, 0444, regulator_uV_show, NULL);
 
 static ssize_t regulator_uA_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
@@ -240,6 +251,7 @@ static ssize_t regulator_uA_show(struct device *dev,
 
 	return sprintf(buf, "%d\n", _regulator_get_current_limit(rdev));
 }
+static DEVICE_ATTR(microamps, 0444, regulator_uA_show, NULL);
 
 static ssize_t regulator_name_show(struct device *dev,
 			     struct device_attribute *attr, char *buf)
@@ -257,12 +269,8 @@ static ssize_t regulator_name_show(struct device *dev,
 	return sprintf(buf, "%s\n", name);
 }
 
-static ssize_t regulator_opmode_show(struct device *dev,
-				    struct device_attribute *attr, char *buf)
+static ssize_t regulator_print_opmode(char *buf, int mode)
 {
-	struct regulator_dev *rdev = dev_get_drvdata(dev);
-	int mode = _regulator_get_mode(rdev);
-
 	switch (mode) {
 	case REGULATOR_MODE_FAST:
 		return sprintf(buf, "fast\n");
@@ -276,12 +284,17 @@ static ssize_t regulator_opmode_show(struct device *dev,
 	return sprintf(buf, "unknown\n");
 }
 
-static ssize_t regulator_state_show(struct device *dev,
-				   struct device_attribute *attr, char *buf)
+static ssize_t regulator_opmode_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
 {
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
-	int state = _regulator_is_enabled(rdev);
 
+	return regulator_print_opmode(buf, _regulator_get_mode(rdev));
+}
+static DEVICE_ATTR(opmode, 0444, regulator_opmode_show, NULL);
+
+static ssize_t regulator_print_state(char *buf, int state)
+{
 	if (state > 0)
 		return sprintf(buf, "enabled\n");
 	else if (state == 0)
@@ -290,6 +303,15 @@ static ssize_t regulator_state_show(struct device *dev,
 		return sprintf(buf, "unknown\n");
 }
 
+static ssize_t regulator_state_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = dev_get_drvdata(dev);
+
+	return regulator_print_state(buf, _regulator_is_enabled(rdev));
+}
+static DEVICE_ATTR(state, 0444, regulator_state_show, NULL);
+
 static ssize_t regulator_min_uA_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)
 {
@@ -300,6 +322,7 @@ static ssize_t regulator_min_uA_show(struct device *dev,
 
 	return sprintf(buf, "%d\n", rdev->constraints->min_uA);
 }
+static DEVICE_ATTR(min_microamps, 0444, regulator_min_uA_show, NULL);
 
 static ssize_t regulator_max_uA_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)
@@ -311,6 +334,7 @@ static ssize_t regulator_max_uA_show(struct device *dev,
 
 	return sprintf(buf, "%d\n", rdev->constraints->max_uA);
 }
+static DEVICE_ATTR(max_microamps, 0444, regulator_max_uA_show, NULL);
 
 static ssize_t regulator_min_uV_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)
@@ -322,6 +346,7 @@ static ssize_t regulator_min_uV_show(struct device *dev,
 
 	return sprintf(buf, "%d\n", rdev->constraints->min_uV);
 }
+static DEVICE_ATTR(min_microvolts, 0444, regulator_min_uV_show, NULL);
 
 static ssize_t regulator_max_uV_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)
@@ -333,6 +358,7 @@ static ssize_t regulator_max_uV_show(struct device *dev,
 
 	return sprintf(buf, "%d\n", rdev->constraints->max_uV);
 }
+static DEVICE_ATTR(max_microvolts, 0444, regulator_max_uV_show, NULL);
 
 static ssize_t regulator_total_uA_show(struct device *dev,
 				      struct device_attribute *attr, char *buf)
@@ -347,6 +373,7 @@ static ssize_t regulator_total_uA_show(struct device *dev,
 	mutex_unlock(&rdev->mutex);
 	return sprintf(buf, "%d\n", uA);
 }
+static DEVICE_ATTR(requested_microamps, 0444, regulator_total_uA_show, NULL);
 
 static ssize_t regulator_num_users_show(struct device *dev,
 				      struct device_attribute *attr, char *buf)
@@ -374,153 +401,106 @@ static ssize_t regulator_suspend_mem_uV_show(struct device *dev,
 {
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
 
-	if (!rdev->constraints)
-		return sprintf(buf, "not defined\n");
 	return sprintf(buf, "%d\n", rdev->constraints->state_mem.uV);
 }
+static DEVICE_ATTR(suspend_mem_microvolts, 0444,
+		regulator_suspend_mem_uV_show, NULL);
 
 static ssize_t regulator_suspend_disk_uV_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
 
-	if (!rdev->constraints)
-		return sprintf(buf, "not defined\n");
 	return sprintf(buf, "%d\n", rdev->constraints->state_disk.uV);
 }
+static DEVICE_ATTR(suspend_disk_microvolts, 0444,
+		regulator_suspend_disk_uV_show, NULL);
 
 static ssize_t regulator_suspend_standby_uV_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
 
-	if (!rdev->constraints)
-		return sprintf(buf, "not defined\n");
 	return sprintf(buf, "%d\n", rdev->constraints->state_standby.uV);
 }
-
-static ssize_t suspend_opmode_show(struct regulator_dev *rdev,
-	unsigned int mode, char *buf)
-{
-	switch (mode) {
-	case REGULATOR_MODE_FAST:
-		return sprintf(buf, "fast\n");
-	case REGULATOR_MODE_NORMAL:
-		return sprintf(buf, "normal\n");
-	case REGULATOR_MODE_IDLE:
-		return sprintf(buf, "idle\n");
-	case REGULATOR_MODE_STANDBY:
-		return sprintf(buf, "standby\n");
-	}
-	return sprintf(buf, "unknown\n");
-}
+static DEVICE_ATTR(suspend_standby_microvolts, 0444,
+		regulator_suspend_standby_uV_show, NULL);
 
 static ssize_t regulator_suspend_mem_mode_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
 
-	if (!rdev->constraints)
-		return sprintf(buf, "not defined\n");
-	return suspend_opmode_show(rdev,
-		rdev->constraints->state_mem.mode, buf);
+	return regulator_print_opmode(buf,
+		rdev->constraints->state_mem.mode);
 }
+static DEVICE_ATTR(suspend_mem_mode, 0444,
+		regulator_suspend_mem_mode_show, NULL);
 
 static ssize_t regulator_suspend_disk_mode_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
 
-	if (!rdev->constraints)
-		return sprintf(buf, "not defined\n");
-	return suspend_opmode_show(rdev,
-		rdev->constraints->state_disk.mode, buf);
+	return regulator_print_opmode(buf,
+		rdev->constraints->state_disk.mode);
 }
+static DEVICE_ATTR(suspend_disk_mode, 0444,
+		regulator_suspend_disk_mode_show, NULL);
 
 static ssize_t regulator_suspend_standby_mode_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
 
-	if (!rdev->constraints)
-		return sprintf(buf, "not defined\n");
-	return suspend_opmode_show(rdev,
-		rdev->constraints->state_standby.mode, buf);
+	return regulator_print_opmode(buf,
+		rdev->constraints->state_standby.mode);
 }
+static DEVICE_ATTR(suspend_standby_mode, 0444,
+		regulator_suspend_standby_mode_show, NULL);
 
 static ssize_t regulator_suspend_mem_state_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
 
-	if (!rdev->constraints)
-		return sprintf(buf, "not defined\n");
-
-	if (rdev->constraints->state_mem.enabled)
-		return sprintf(buf, "enabled\n");
-	else
-		return sprintf(buf, "disabled\n");
+	return regulator_print_state(buf,
+			rdev->constraints->state_mem.enabled);
 }
+static DEVICE_ATTR(suspend_mem_state, 0444,
+		regulator_suspend_mem_state_show, NULL);
 
 static ssize_t regulator_suspend_disk_state_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
 
-	if (!rdev->constraints)
-		return sprintf(buf, "not defined\n");
-
-	if (rdev->constraints->state_disk.enabled)
-		return sprintf(buf, "enabled\n");
-	else
-		return sprintf(buf, "disabled\n");
+	return regulator_print_state(buf,
+			rdev->constraints->state_disk.enabled);
 }
+static DEVICE_ATTR(suspend_disk_state, 0444,
+		regulator_suspend_disk_state_show, NULL);
 
 static ssize_t regulator_suspend_standby_state_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
 
-	if (!rdev->constraints)
-		return sprintf(buf, "not defined\n");
-
-	if (rdev->constraints->state_standby.enabled)
-		return sprintf(buf, "enabled\n");
-	else
-		return sprintf(buf, "disabled\n");
+	return regulator_print_state(buf,
+			rdev->constraints->state_standby.enabled);
 }
+static DEVICE_ATTR(suspend_standby_state, 0444,
+		regulator_suspend_standby_state_show, NULL);
 
+
+/*
+ * These are the only attributes are present for all regulators.
+ * Other attributes are a function of regulator functionality.
+ */
 static struct device_attribute regulator_dev_attrs[] = {
 	__ATTR(name, 0444, regulator_name_show, NULL),
-	__ATTR(microvolts, 0444, regulator_uV_show, NULL),
-	__ATTR(microamps, 0444, regulator_uA_show, NULL),
-	__ATTR(opmode, 0444, regulator_opmode_show, NULL),
-	__ATTR(state, 0444, regulator_state_show, NULL),
-	__ATTR(min_microvolts, 0444, regulator_min_uV_show, NULL),
-	__ATTR(min_microamps, 0444, regulator_min_uA_show, NULL),
-	__ATTR(max_microvolts, 0444, regulator_max_uV_show, NULL),
-	__ATTR(max_microamps, 0444, regulator_max_uA_show, NULL),
-	__ATTR(requested_microamps, 0444, regulator_total_uA_show, NULL),
 	__ATTR(num_users, 0444, regulator_num_users_show, NULL),
 	__ATTR(type, 0444, regulator_type_show, NULL),
-	__ATTR(suspend_mem_microvolts, 0444,
-		regulator_suspend_mem_uV_show, NULL),
-	__ATTR(suspend_disk_microvolts, 0444,
-		regulator_suspend_disk_uV_show, NULL),
-	__ATTR(suspend_standby_microvolts, 0444,
-		regulator_suspend_standby_uV_show, NULL),
-	__ATTR(suspend_mem_mode, 0444,
-		regulator_suspend_mem_mode_show, NULL),
-	__ATTR(suspend_disk_mode, 0444,
-		regulator_suspend_disk_mode_show, NULL),
-	__ATTR(suspend_standby_mode, 0444,
-		regulator_suspend_standby_mode_show, NULL),
-	__ATTR(suspend_mem_state, 0444,
-		regulator_suspend_mem_state_show, NULL),
-	__ATTR(suspend_disk_state, 0444,
-		regulator_suspend_disk_state_show, NULL),
-	__ATTR(suspend_standby_state, 0444,
-		regulator_suspend_standby_state_show, NULL),
 	__ATTR_NULL,
 };
 
@@ -675,7 +655,8 @@ static void print_constraints(struct regulator_dev *rdev)
 
 /**
  * set_machine_constraints - sets regulator constraints
- * @regulator: regulator source
+ * @rdev: regulator source
+ * @constraints: constraints to apply
  *
  * Allows platform initialisation code to define and constrain
  * regulator circuits e.g. valid voltage/current ranges, etc.  NOTE:
@@ -750,8 +731,8 @@ out:
 
 /**
  * set_supply - set regulator supply regulator
- * @regulator: regulator name
- * @supply: supply regulator name
+ * @rdev: regulator name
+ * @supply_rdev: supply regulator name
  *
  * Called by platform initialisation code to set the supply regulator for this
  * regulator. This ensures that a regulators supply will also be enabled by the
@@ -778,9 +759,9 @@ out:
 
 /**
  * set_consumer_device_supply: Bind a regulator to a symbolic supply
- * @regulator: regulator source
- * @dev:       device the supply applies to
- * @supply:    symbolic name for supply
+ * @rdev:         regulator source
+ * @consumer_dev: device the supply applies to
+ * @supply:       symbolic name for supply
  *
  * Allows platform initialisation code to map physical regulator
  * sources to symbolic names for supplies for use by devices.  Devices
@@ -795,6 +776,20 @@ static int set_consumer_device_supply(struct regulator_dev *rdev,
 	if (supply == NULL)
 		return -EINVAL;
 
+	list_for_each_entry(node, &regulator_map_list, list) {
+		if (consumer_dev != node->dev)
+			continue;
+		if (strcmp(node->supply, supply) != 0)
+			continue;
+
+		dev_dbg(consumer_dev, "%s/%s is '%s' supply; fail %s/%s\n",
+				dev_name(&node->regulator->dev),
+				node->regulator->desc->name,
+				supply,
+				dev_name(&rdev->dev), rdev->desc->name);
+		return -EBUSY;
+	}
+
 	node = kmalloc(sizeof(struct regulator_map), GFP_KERNEL);
 	if (node == NULL)
 		return -ENOMEM;
@@ -963,16 +958,13 @@ void regulator_put(struct regulator *regulator)
 	if (regulator == NULL || IS_ERR(regulator))
 		return;
 
-	if (regulator->enabled) {
-		printk(KERN_WARNING "Releasing supply %s while enabled\n",
-		       regulator->supply_name);
-		WARN_ON(regulator->enabled);
-		regulator_disable(regulator);
-	}
-
 	mutex_lock(&regulator_list_mutex);
 	rdev = regulator->rdev;
 
+	if (WARN(regulator->enabled, "Releasing supply %s while enabled\n",
+			       regulator->supply_name))
+		_regulator_disable(rdev);
+
 	/* remove any sysfs entries */
 	if (regulator->dev) {
 		sysfs_remove_link(&rdev->dev.kobj, regulator->supply_name);
@@ -1034,29 +1026,26 @@ static int _regulator_enable(struct regulator_dev *rdev)
  * regulator_enable - enable regulator output
  * @regulator: regulator source
  *
- * Enable the regulator output at the predefined voltage or current value.
+ * Request that the regulator be enabled with the regulator output at
+ * the predefined voltage or current value.  Calls to regulator_enable()
+ * must be balanced with calls to regulator_disable().
+ *
  * NOTE: the output value can be set by other drivers, boot loader or may be
  * hardwired in the regulator.
- * NOTE: calls to regulator_enable() must be balanced with calls to
- * regulator_disable().
  */
 int regulator_enable(struct regulator *regulator)
 {
-	int ret;
-
-	if (regulator->enabled) {
-		printk(KERN_CRIT "Regulator %s already enabled\n",
-		       regulator->supply_name);
-		WARN_ON(regulator->enabled);
-		return 0;
-	}
+	struct regulator_dev *rdev = regulator->rdev;
+	int ret = 0;
 
-	mutex_lock(&regulator->rdev->mutex);
-	regulator->enabled = 1;
-	ret = _regulator_enable(regulator->rdev);
-	if (ret != 0)
-		regulator->enabled = 0;
-	mutex_unlock(&regulator->rdev->mutex);
+	mutex_lock(&rdev->mutex);
+	if (regulator->enabled == 0)
+		ret = _regulator_enable(rdev);
+	else if (regulator->enabled < 0)
+		ret = -EIO;
+	if (ret == 0)
+		regulator->enabled++;
+	mutex_unlock(&rdev->mutex);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_enable);
@@ -1100,27 +1089,31 @@ static int _regulator_disable(struct regulator_dev *rdev)
  * regulator_disable - disable regulator output
  * @regulator: regulator source
  *
- * Disable the regulator output voltage or current.
- * NOTE: this will only disable the regulator output if no other consumer
- * devices have it enabled.
- * NOTE: calls to regulator_enable() must be balanced with calls to
+ * Disable the regulator output voltage or current.  Calls to
+ * regulator_enable() must be balanced with calls to
  * regulator_disable().
+ *
+ * NOTE: this will only disable the regulator output if no other consumer
+ * devices have it enabled, the regulator device supports disabling and
+ * machine constraints permit this operation.
  */
 int regulator_disable(struct regulator *regulator)
 {
-	int ret;
-
-	if (!regulator->enabled) {
-		printk(KERN_ERR "%s: not in use by this consumer\n",
-			__func__);
-		return 0;
-	}
+	struct regulator_dev *rdev = regulator->rdev;
+	int ret = 0;
 
-	mutex_lock(&regulator->rdev->mutex);
-	regulator->enabled = 0;
-	regulator->uA_load = 0;
-	ret = _regulator_disable(regulator->rdev);
-	mutex_unlock(&regulator->rdev->mutex);
+	mutex_lock(&rdev->mutex);
+	if (regulator->enabled == 1) {
+		ret = _regulator_disable(rdev);
+		if (ret == 0)
+			regulator->uA_load = 0;
+	} else if (WARN(regulator->enabled <= 0,
+			"unbalanced disables for supply %s\n",
+			regulator->supply_name))
+		ret = -EIO;
+	if (ret == 0)
+		regulator->enabled--;
+	mutex_unlock(&rdev->mutex);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_disable);
@@ -1196,7 +1189,13 @@ out:
  * regulator_is_enabled - is the regulator output enabled
  * @regulator: regulator source
  *
- * Returns zero for disabled otherwise return number of enable requests.
+ * Returns positive if the regulator driver backing the source/client
+ * has requested that the device be enabled, zero if it hasn't, else a
+ * negative errno code.
+ *
+ * Note that the device backing this regulator handle can have multiple
+ * users, so it might be enabled even if regulator_enable() was never
+ * called for this particular source.
  */
 int regulator_is_enabled(struct regulator *regulator)
 {
@@ -1219,7 +1218,7 @@ EXPORT_SYMBOL_GPL(regulator_is_enabled);
  *
  * NOTE: If the regulator is shared between several devices then the lowest
  * request voltage that meets the system constraints will be used.
- * NOTE: Regulator system constraints must be set for this regulator before
+ * Regulator system constraints must be set for this regulator before
  * calling this function otherwise this call will fail.
  */
 int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
@@ -1493,7 +1492,8 @@ int regulator_set_optimum_mode(struct regulator *regulator, int uA_load)
 	mode = rdev->desc->ops->get_optimum_mode(rdev,
 						 input_uV, output_uV,
 						 total_uA_load);
-	if (ret <= 0) {
+	ret = regulator_check_mode(rdev, mode);
+	if (ret < 0) {
 		printk(KERN_ERR "%s: failed to get optimum mode for %s @"
 			" %d uA %d -> %d uV\n", __func__, rdev->desc->name,
 			total_uA_load, input_uV, output_uV);
@@ -1501,7 +1501,7 @@ int regulator_set_optimum_mode(struct regulator *regulator, int uA_load)
 	}
 
 	ret = rdev->desc->ops->set_mode(rdev, mode);
-	if (ret <= 0) {
+	if (ret < 0) {
 		printk(KERN_ERR "%s: failed to set optimum mode %x for %s\n",
 			__func__, mode, rdev->desc->name);
 		goto out;
@@ -1516,7 +1516,7 @@ EXPORT_SYMBOL_GPL(regulator_set_optimum_mode);
 /**
  * regulator_register_notifier - register regulator event notifier
  * @regulator: regulator source
- * @notifier_block: notifier block
+ * @nb: notifier block
  *
  * Register notifier block to receive regulator events.
  */
@@ -1531,7 +1531,7 @@ EXPORT_SYMBOL_GPL(regulator_register_notifier);
 /**
  * regulator_unregister_notifier - unregister regulator event notifier
  * @regulator: regulator source
- * @notifier_block: notifier block
+ * @nb: notifier block
  *
  * Unregister regulator event notifier block.
  */
@@ -1697,9 +1697,9 @@ EXPORT_SYMBOL_GPL(regulator_bulk_free);
 
 /**
  * regulator_notifier_call_chain - call regulator event notifier
- * @regulator: regulator source
+ * @rdev: regulator source
  * @event: notifier block
- * @data:
+ * @data: callback-specific data.
  *
  * Called by regulator drivers to notify clients a regulator event has
  * occurred. We also notify regulator clients downstream.
@@ -1713,10 +1713,122 @@ int regulator_notifier_call_chain(struct regulator_dev *rdev,
 }
 EXPORT_SYMBOL_GPL(regulator_notifier_call_chain);
 
+/*
+ * To avoid cluttering sysfs (and memory) with useless state, only
+ * create attributes that can be meaningfully displayed.
+ */
+static int add_regulator_attributes(struct regulator_dev *rdev)
+{
+	struct device		*dev = &rdev->dev;
+	struct regulator_ops	*ops = rdev->desc->ops;
+	int			status = 0;
+
+	/* some attributes need specific methods to be displayed */
+	if (ops->get_voltage) {
+		status = device_create_file(dev, &dev_attr_microvolts);
+		if (status < 0)
+			return status;
+	}
+	if (ops->get_current_limit) {
+		status = device_create_file(dev, &dev_attr_microamps);
+		if (status < 0)
+			return status;
+	}
+	if (ops->get_mode) {
+		status = device_create_file(dev, &dev_attr_opmode);
+		if (status < 0)
+			return status;
+	}
+	if (ops->is_enabled) {
+		status = device_create_file(dev, &dev_attr_state);
+		if (status < 0)
+			return status;
+	}
+
+	/* some attributes are type-specific */
+	if (rdev->desc->type == REGULATOR_CURRENT) {
+		status = device_create_file(dev, &dev_attr_requested_microamps);
+		if (status < 0)
+			return status;
+	}
+
+	/* all the other attributes exist to support constraints;
+	 * don't show them if there are no constraints, or if the
+	 * relevant supporting methods are missing.
+	 */
+	if (!rdev->constraints)
+		return status;
+
+	/* constraints need specific supporting methods */
+	if (ops->set_voltage) {
+		status = device_create_file(dev, &dev_attr_min_microvolts);
+		if (status < 0)
+			return status;
+		status = device_create_file(dev, &dev_attr_max_microvolts);
+		if (status < 0)
+			return status;
+	}
+	if (ops->set_current_limit) {
+		status = device_create_file(dev, &dev_attr_min_microamps);
+		if (status < 0)
+			return status;
+		status = device_create_file(dev, &dev_attr_max_microamps);
+		if (status < 0)
+			return status;
+	}
+
+	/* suspend mode constraints need multiple supporting methods */
+	if (!(ops->set_suspend_enable && ops->set_suspend_disable))
+		return status;
+
+	status = device_create_file(dev, &dev_attr_suspend_standby_state);
+	if (status < 0)
+		return status;
+	status = device_create_file(dev, &dev_attr_suspend_mem_state);
+	if (status < 0)
+		return status;
+	status = device_create_file(dev, &dev_attr_suspend_disk_state);
+	if (status < 0)
+		return status;
+
+	if (ops->set_suspend_voltage) {
+		status = device_create_file(dev,
+				&dev_attr_suspend_standby_microvolts);
+		if (status < 0)
+			return status;
+		status = device_create_file(dev,
+				&dev_attr_suspend_mem_microvolts);
+		if (status < 0)
+			return status;
+		status = device_create_file(dev,
+				&dev_attr_suspend_disk_microvolts);
+		if (status < 0)
+			return status;
+	}
+
+	if (ops->set_suspend_mode) {
+		status = device_create_file(dev,
+				&dev_attr_suspend_standby_mode);
+		if (status < 0)
+			return status;
+		status = device_create_file(dev,
+				&dev_attr_suspend_mem_mode);
+		if (status < 0)
+			return status;
+		status = device_create_file(dev,
+				&dev_attr_suspend_disk_mode);
+		if (status < 0)
+			return status;
+	}
+
+	return status;
+}
+
 /**
  * regulator_register - register regulator
- * @regulator: regulator source
- * @reg_data: private regulator data
+ * @regulator_desc: regulator to register
+ * @dev: struct device for the regulator
+ * @driver_data: private regulator data
  *
  * Called by regulator drivers to register a regulator.
  * Returns 0 on success.
@@ -1761,45 +1873,37 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
 	/* preform any regulator specific init */
 	if (init_data->regulator_init) {
 		ret = init_data->regulator_init(rdev->reg_data);
-		if (ret < 0) {
-			kfree(rdev);
-			rdev = ERR_PTR(ret);
-			goto out;
-		}
-	}
-
-	/* set regulator constraints */
-	ret = set_machine_constraints(rdev, &init_data->constraints);
-	if (ret < 0) {
-		kfree(rdev);
-		rdev = ERR_PTR(ret);
-		goto out;
+		if (ret < 0)
+			goto clean;
 	}
 
 	/* register with sysfs */
 	rdev->dev.class = &regulator_class;
 	rdev->dev.parent = dev;
-	snprintf(rdev->dev.bus_id, sizeof(rdev->dev.bus_id),
-		 "regulator.%d", atomic_inc_return(&regulator_no) - 1);
+	dev_set_name(&rdev->dev, "regulator.%d",
+		     atomic_inc_return(&regulator_no) - 1);
 	ret = device_register(&rdev->dev);
-	if (ret != 0) {
-		kfree(rdev);
-		rdev = ERR_PTR(ret);
-		goto out;
-	}
+	if (ret != 0)
+		goto clean;
 
 	dev_set_drvdata(&rdev->dev, rdev);
 
+	/* set regulator constraints */
+	ret = set_machine_constraints(rdev, &init_data->constraints);
+	if (ret < 0)
+		goto scrub;
+
+	/* add attributes supported by this regulator */
+	ret = add_regulator_attributes(rdev);
+	if (ret < 0)
+		goto scrub;
+
 	/* set supply regulator if it exists */
 	if (init_data->supply_regulator_dev) {
 		ret = set_supply(rdev,
 			dev_get_drvdata(init_data->supply_regulator_dev));
-		if (ret < 0) {
-			device_unregister(&rdev->dev);
-			kfree(rdev);
-			rdev = ERR_PTR(ret);
-			goto out;
-		}
+		if (ret < 0)
+			goto scrub;
 	}
 
 	/* add consumers devices */
@@ -1811,10 +1915,7 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
 			for (--i; i >= 0; i--)
 				unset_consumer_device_supply(rdev,
 					init_data->consumer_supplies[i].dev);
-			device_unregister(&rdev->dev);
-			kfree(rdev);
-			rdev = ERR_PTR(ret);
-			goto out;
+			goto scrub;
 		}
 	}
 
@@ -1822,12 +1923,19 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
 out:
 	mutex_unlock(&regulator_list_mutex);
 	return rdev;
+
+scrub:
+	device_unregister(&rdev->dev);
+clean:
+	kfree(rdev);
+	rdev = ERR_PTR(ret);
+	goto out;
 }
 EXPORT_SYMBOL_GPL(regulator_register);
 
 /**
  * regulator_unregister - unregister regulator
- * @regulator: regulator source
+ * @rdev: regulator to unregister
  *
  * Called by regulator drivers to unregister a regulator.
  */
@@ -1846,7 +1954,7 @@ void regulator_unregister(struct regulator_dev *rdev)
 EXPORT_SYMBOL_GPL(regulator_unregister);
 
 /**
- * regulator_suspend_prepare: prepare regulators for system wide suspend
+ * regulator_suspend_prepare - prepare regulators for system wide suspend
  * @state: system suspend state
  *
  * Configure each regulator with it's suspend operating parameters for state.
@@ -1882,7 +1990,7 @@ EXPORT_SYMBOL_GPL(regulator_suspend_prepare);
 
 /**
  * rdev_get_drvdata - get rdev regulator driver data
- * @regulator: regulator
+ * @rdev: regulator
  *
  * Get rdev regulator driver private data. This call can be used in the
  * regulator driver context.
@@ -1919,7 +2027,7 @@ EXPORT_SYMBOL_GPL(regulator_set_drvdata);
 
 /**
  * regulator_get_id - get regulator ID
- * @regulator: regulator
+ * @rdev: regulator
  */
 int rdev_get_id(struct regulator_dev *rdev)
 {
diff --git a/drivers/regulator/da903x.c b/drivers/regulator/da903x.c
index 773b29cec8b..fe77730a7ed 100644
--- a/drivers/regulator/da903x.c
+++ b/drivers/regulator/da903x.c
@@ -102,7 +102,7 @@ static int da903x_set_ldo_voltage(struct regulator_dev *rdev,
 	uint8_t val, mask;
 
 	if (check_range(info, min_uV, max_uV)) {
-		pr_err("invalid voltage range (%d, %d) uV", min_uV, max_uV);
+		pr_err("invalid voltage range (%d, %d) uV\n", min_uV, max_uV);
 		return -EINVAL;
 	}
 
@@ -159,7 +159,7 @@ static int da903x_is_enabled(struct regulator_dev *rdev)
 	if (ret)
 		return ret;
 
-	return reg_val & (1 << info->enable_bit);
+	return !!(reg_val & (1 << info->enable_bit));
 }
 
 /* DA9030 specific operations */
@@ -172,7 +172,7 @@ static int da9030_set_ldo1_15_voltage(struct regulator_dev *rdev,
 	int ret;
 
 	if (check_range(info, min_uV, max_uV)) {
-		pr_err("invalid voltage range (%d, %d) uV", min_uV, max_uV);
+		pr_err("invalid voltage range (%d, %d) uV\n", min_uV, max_uV);
 		return -EINVAL;
 	}
 
@@ -199,7 +199,7 @@ static int da9030_set_ldo14_voltage(struct regulator_dev *rdev,
 	int thresh;
 
 	if (check_range(info, min_uV, max_uV)) {
-		pr_err("invalid voltage range (%d, %d) uV", min_uV, max_uV);
+		pr_err("invalid voltage range (%d, %d) uV\n", min_uV, max_uV);
 		return -EINVAL;
 	}
 
@@ -248,7 +248,7 @@ static int da9034_set_dvc_voltage(struct regulator_dev *rdev,
 	int ret;
 
 	if (check_range(info, min_uV, max_uV)) {
-		pr_err("invalid voltage range (%d, %d) uV", min_uV, max_uV);
+		pr_err("invalid voltage range (%d, %d) uV\n", min_uV, max_uV);
 		return -EINVAL;
 	}
 
@@ -273,7 +273,7 @@ static int da9034_set_ldo12_voltage(struct regulator_dev *rdev,
 	uint8_t val, mask;
 
 	if (check_range(info, min_uV, max_uV)) {
-		pr_err("invalid voltage range (%d, %d) uV", min_uV, max_uV);
+		pr_err("invalid voltage range (%d, %d) uV\n", min_uV, max_uV);
 		return -EINVAL;
 	}
 
diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h
index afdc4558bb9..801bf77ff4e 100644
--- a/include/linux/regulator/consumer.h
+++ b/include/linux/regulator/consumer.h
@@ -104,10 +104,10 @@ struct regulator;
 /**
  * struct regulator_bulk_data - Data used for bulk regulator operations.
  *
- * @supply   The name of the supply.  Initialised by the user before
- *           using the bulk regulator APIs.
- * @consumer The regulator consumer for the supply.  This will be managed
- *           by the bulk API.
+ * @supply:   The name of the supply.  Initialised by the user before
+ *            using the bulk regulator APIs.
+ * @consumer: The regulator consumer for the supply.  This will be managed
+ *            by the bulk API.
  *
  * The regulator APIs provide a series of regulator_bulk_() API calls as
  * a convenience to consumers which require multiple supplies.  This
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index e37d8056198..2dae05705f1 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -24,7 +24,33 @@ struct regulator_init_data;
 /**
  * struct regulator_ops - regulator operations.
  *
- * This struct describes regulator operations.
+ * This struct describes regulator operations which can be implemented by
+ * regulator chip drivers.
+ *
+ * @enable: Enable the regulator.
+ * @disable: Disable the regulator.
+ * @is_enabled: Return 1 if the regulator is enabled, 0 otherwise.
+ *
+ * @set_voltage: Set the voltage for the regulator within the range specified.
+ *               The driver should select the voltage closest to min_uV.
+ * @get_voltage: Return the currently configured voltage for the regulator.
+ *
+ * @set_current_limit: Configure a limit for a current-limited regulator.
+ * @get_current_limit: Get the limit for a current-limited regulator.
+ *
+ * @set_mode: Set the operating mode for the regulator.
+ * @get_mode: Get the current operating mode for the regulator.
+ * @get_optimum_mode: Get the most efficient operating mode for the regulator
+ *                    when running with the specified parameters.
+ *
+ * @set_suspend_voltage: Set the voltage for the regulator when the system
+ *                       is suspended.
+ * @set_suspend_enable: Mark the regulator as enabled when the system is
+ *                      suspended.
+ * @set_suspend_disable: Mark the regulator as disabled when the system is
+ *                       suspended.
+ * @set_suspend_mode: Set the operating mode for the regulator when the
+ *                    system is suspended.
  */
 struct regulator_ops {
 
@@ -75,6 +101,15 @@ enum regulator_type {
 /**
  * struct regulator_desc - Regulator descriptor
  *
+ * Each regulator registered with the core is described with a structure of
+ * this type.
+ *
+ * @name: Identifying name for the regulator.
+ * @id: Numerical identifier for the regulator.
+ * @ops: Regulator operations table.
+ * @irq: Interrupt number for the regulator.
+ * @type: Indicates if the regulator is a voltage or current regulator.
+ * @owner: Module providing the regulator, used for refcounting.
  */
 struct regulator_desc {
 	const char *name;
diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h
index c6d69331a81..3794773b23d 100644
--- a/include/linux/regulator/machine.h
+++ b/include/linux/regulator/machine.h
@@ -44,6 +44,10 @@ struct regulator;
  * struct regulator_state - regulator state during low power syatem states
  *
  * This describes a regulators state during a system wide low power state.
+ *
+ * @uV: Operating voltage during suspend.
+ * @mode: Operating mode during suspend.
+ * @enabled: Enabled during suspend.
  */
 struct regulator_state {
 	int uV;	/* suspend voltage */
@@ -55,6 +59,30 @@ struct regulator_state {
  * struct regulation_constraints - regulator operating constraints.
  *
  * This struct describes regulator and board/machine specific constraints.
+ *
+ * @name: Descriptive name for the constraints, used for display purposes.
+ *
+ * @min_uV: Smallest voltage consumers may set.
+ * @max_uV: Largest voltage consumers may set.
+ *
+ * @min_uA: Smallest consumers consumers may set.
+ * @max_uA: Largest current consumers may set.
+ *
+ * @valid_modes_mask: Mask of modes which may be configured by consumers.
+ * @valid_ops_mask: Operations which may be performed by consumers.
+ *
+ * @always_on: Set if the regulator should never be disabled.
+ * @boot_on: Set if the regulator is enabled when the system is initially
+ *           started.
+ * @apply_uV: Apply the voltage constraint when initialising.
+ *
+ * @input_uV: Input voltage for regulator when supplied by another regulator.
+ *
+ * @state_disk: State for regulator when system is suspended in disk mode.
+ * @state_mem: State for regulator when system is suspended in mem mode.
+ * @state_standby: State for regulator when system is suspended in standby
+ *                 mode.
+ * @initial_state: Suspend state to set by default.
  */
 struct regulation_constraints {
 
@@ -93,6 +121,9 @@ struct regulation_constraints {
  * struct regulator_consumer_supply - supply -> device mapping
  *
  * This maps a supply name to a device.
+ *
+ * @dev: Device structure for the consumer.
+ * @supply: Name for the supply.
  */
 struct regulator_consumer_supply {
 	struct device *dev;	/* consumer */
@@ -103,6 +134,16 @@ struct regulator_consumer_supply {
  * struct regulator_init_data - regulator platform initialisation data.
  *
  * Initialisation constraints, our supply and consumers supplies.
+ *
+ * @supply_regulator_dev: Parent regulator (if any).
+ *
+ * @constraints: Constraints.  These must be specified for the regulator to
+ *               be usable.
+ * @num_consumer_supplies: Number of consumer device supplies.
+ * @consumer_supplies: Consumer device supply configuration.
+ *
+ * @regulator_init: Callback invoked when the regulator has been registered.
+ * @driver_data: Data passed to regulator_init.
  */
 struct regulator_init_data {
 	struct device *supply_regulator_dev; /* or NULL for LINE */