clk: sunxi-ng: Implement global pre-divider

Some clocks have a global pre-divider that applies to all their parents.

Since it might also apply to clocks that have a single parent, this is
merged in the ccu_common structure, unlike the other pre-divider settings
that are tied to a specific index, and thus a specific parent.

Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

2 files changed, 9 insertions, 1 deletions

diff --git a/drivers/clk/sunxi-ng/ccu_common.h b/drivers/clk/sunxi-ng/ccu_common.h
index b3d9abfbd721..cdd69eb2e0b9 100644
--- a/drivers/clk/sunxi-ng/ccu_common.h
+++ b/drivers/clk/sunxi-ng/ccu_common.h
@@ -21,6 +21,7 @@
 #define CCU_FEATURE_VARIABLE_PREDIV     BIT(1)
 #define CCU_FEATURE_FIXED_PREDIV        BIT(2)
 #define CCU_FEATURE_FIXED_POSTDIV       BIT(3)
+#define CCU_FEATURE_ALL_PREDIV          BIT(4)
 
 struct device_node;
 
@@ -56,6 +57,7 @@ struct device_node;
 struct ccu_common {
         void __iomem    *base;
         u16             reg;
+        u32             prediv;
 
         unsigned long   features;
         spinlock_t      *lock;
diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
index a43ad52a957d..858a48621631 100644
--- a/drivers/clk/sunxi-ng/ccu_mux.c
+++ b/drivers/clk/sunxi-ng/ccu_mux.c
@@ -25,9 +25,15 @@ void ccu_mux_helper_adjust_parent_for_prediv(struct ccu_common *common,
         int i;
 
         if (!((common->features & CCU_FEATURE_FIXED_PREDIV) ||
-              (common->features & CCU_FEATURE_VARIABLE_PREDIV)))
+              (common->features & CCU_FEATURE_VARIABLE_PREDIV) ||
+              (common->features & CCU_FEATURE_ALL_PREDIV)))
                 return;
 
+        if (common->features & CCU_FEATURE_ALL_PREDIV) {
+                *parent_rate = *parent_rate / common->prediv;
+                return;
+        }
+
         reg = readl(common->base + common->reg);
         if (parent_index < 0) {
                 parent_index = reg >> cm->shift;