clk: introduce clk_set_phase function & callback

A common operation for a clock signal generator is to shift the phase of
that signal. This patch introduces a new function to the clk.h API to
dynamically adjust the phase of a clock signal. Additionally this patch
introduces support for the new function in the common clock framework
via the .set_phase call back in struct clk_ops.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 411dd7eb2653..201a6195a3eb 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -129,6 +129,10 @@ struct dentry;
  *              set then clock accuracy will be initialized to parent accuracy
  *              or 0 (perfect clock) if clock has no parent.
  *
+ * @set_phase:  Shift the phase this clock signal in degrees specified
+ *              by the second argument. Valid values for degrees are
+ *              0-359. Return 0 on success, otherwise -EERROR.
+ *
  * @init:       Perform platform-specific initialization magic.
  *              This is not not used by any of the basic clock types.
  *              Please consider other ways of solving initialization problems
@@ -177,6 +181,7 @@ struct clk_ops {
                                     unsigned long parent_rate, u8 index);
         unsigned long   (*recalc_accuracy)(struct clk_hw *hw,
                                            unsigned long parent_accuracy);
+        int             (*set_phase)(struct clk_hw *hw, int degrees);
         void            (*init)(struct clk_hw *hw);
         int             (*debug_init)(struct clk_hw *hw, struct dentry *dentry);
 };