clk: add clk_ignore_unused option to keep boot clocks on

This is primarily useful when there's a driver that doesn't claim clocks
properly, but the bootloader leaves them on. It's not expected to be used
in normal cases, but for bringup and debug it's very useful to have the
option to not gate unclaimed clocks that are still on.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed up trivial merge issue]

1 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 4609e81dbc37..9aa5562fed9c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -44,6 +44,7 @@ parameter is applicable:
         AVR32   AVR32 architecture is enabled.
         AX25    Appropriate AX.25 support is enabled.
         BLACKFIN Blackfin architecture is enabled.
+        CLK     Common clock infrastructure is enabled.
         DRM     Direct Rendering Management support is enabled.
         DYNAMIC_DEBUG Build in debug messages and enable them at runtime
         EDD     BIOS Enhanced Disk Drive Services (EDD) is enabled
@@ -465,6 +466,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
         cio_ignore=     [S390]
                         See Documentation/s390/CommonIO for details.
+        clk_ignore_unused
+                        [CLK]
+                        Keep all clocks already enabled by bootloader on,
+                        even if no driver has claimed them. This is useful
+                        for debug and development, but should not be
+                        needed on a platform with proper driver support.
+                        For more information, see Documentation/clk.txt.
 
         clock=          [BUGS=X86-32, HW] gettimeofday clocksource override.
                         [Deprecated]