clk: Add a function to retrieve phase

The current phase API doesn't look into the actual hardware to get the phase
value, but will rather get it from a variable only set by the set_phase
function.

This will cause issue when the client driver will never call the set_phase
function, where we can end up having a reported phase that will not match what
the hardware has been programmed to by the bootloader or what phase is
programmed out of reset.

Add a new get_phase function for the drivers to implement so that we can get
this value.

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, 10 insertions, 0 deletions

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index d87661af0c72..113d75db371d 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1934,6 +1934,16 @@ int __clk_init(struct device *dev, struct clk *clk)
 		clk->accuracy = 0;
 
 	/*
+	 * Set clk's phase.
+	 * Since a phase is by definition relative to its parent, just
+	 * query the current clock phase, or just assume it's in phase.
+	 */
+	if (clk->ops->get_phase)
+		clk->phase = clk->ops->get_phase(clk->hw);
+	else
+		clk->phase = 0;
+
+	/*
 	 * Set clk's rate.  The preferred method is to use .recalc_rate.  For
 	 * simple clocks and lazy developers the default fallback is to use the
 	 * parent's rate.  If a clock doesn't have a parent (or is orphaned)