Merge remote-tracking branch 'upstream/master' into queue

Merging critical fixes from upstream required for development.

* upstream/master: (809 commits)
  libata: Add a space to " 2GB ATA Flash Disk" DMA blacklist entry
  Revert "powerpc: Update g5_defconfig"
  powerpc/perf: Use pmc_overflow() to detect rolled back events
  powerpc: Fix VMX in interrupt check in POWER7 copy loops
  powerpc: POWER7 copy_to_user/copy_from_user patch applied twice
  powerpc: Fix personality handling in ppc64_personality()
  powerpc/dma-iommu: Fix IOMMU window check
  powerpc: Remove unnecessary ifdefs
  powerpc/kgdb: Restore current_thread_info properly
  powerpc/kgdb: Bail out of KGDB when we've been triggered
  powerpc/kgdb: Do not set kgdb_single_step on ppc
  powerpc/mpic_msgr: Add missing includes
  powerpc: Fix null pointer deref in perf hardware breakpoints
  powerpc: Fixup whitespace in xmon
  powerpc: Fix xmon dl command for new printk implementation
  xfs: check for possible overflow in xfs_ioc_trim
  xfs: unlock the AGI buffer when looping in xfs_dialloc
  xfs: fix uninitialised variable in xfs_rtbuf_get()
  powerpc/fsl: fix "Failed to mount /dev: No such device" errors
  powerpc/fsl: update defconfigs
  ...

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 25 insertions, 6 deletions

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 8fc3808d7a3..90c5c7357a5 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -1,12 +1,31 @@
 menuconfig PWM
-	bool "PWM Support"
+	bool "Pulse-Width Modulation (PWM) Support"
 	depends on !MACH_JZ4740 && !PUV3_PWM
 	help
-	  This enables PWM support through the generic PWM framework.
-	  You only need to enable this, if you also want to enable
-	  one or more of the PWM drivers below.
-
-	  If unsure, say N.
+	  Generic Pulse-Width Modulation (PWM) support.
+
+	  In Pulse-Width Modulation, a variation of the width of pulses
+	  in a rectangular pulse signal is used as a means to alter the
+	  average power of the signal. Applications include efficient
+	  power delivery and voltage regulation. In computer systems,
+	  PWMs are commonly used to control fans or the brightness of
+	  display backlights.
+
+	  This framework provides a generic interface to PWM devices
+	  within the Linux kernel. On the driver side it provides an API
+	  to register and unregister a PWM chip, an abstraction of a PWM
+	  controller, that supports one or more PWM devices. Client
+	  drivers can request PWM devices and use the generic framework
+	  to configure as well as enable and disable them.
+
+	  This generic framework replaces the legacy PWM framework which
+	  allows only a single driver implementing the required API. Not
+	  all legacy implementations have been ported to the framework
+	  yet. The framework provides an API that is backward compatible
+	  with the legacy framework so that existing client drivers
+	  continue to work as expected.
+
+	  If unsure, say no.
 
 if PWM