clk: mux: add explicit big endian support

Add a clock specific flag to switch register accesses to big endian, to
allow runtime configuration of big endian mux clocks.

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

2 files changed, 23 insertions, 3 deletions

diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c
index 2ad2df2e8909..61ad331b7ff4 100644
--- a/drivers/clk/clk-mux.c
+++ b/drivers/clk/clk-mux.c
@@ -23,6 +23,22 @@
  * parent - parent is adjustable through clk_set_parent
  */
 
+static inline u32 clk_mux_readl(struct clk_mux *mux)
+{
+        if (mux->flags & CLK_MUX_BIG_ENDIAN)
+                return ioread32be(mux->reg);
+
+        return clk_readl(mux->reg);
+}
+
+static inline void clk_mux_writel(struct clk_mux *mux, u32 val)
+{
+        if (mux->flags & CLK_MUX_BIG_ENDIAN)
+                iowrite32be(val, mux->reg);
+        else
+                clk_writel(val, mux->reg);
+}
+
 int clk_mux_val_to_index(struct clk_hw *hw, u32 *table, unsigned int flags,
                          unsigned int val)
 {
@@ -73,7 +89,7 @@ static u8 clk_mux_get_parent(struct clk_hw *hw)
         struct clk_mux *mux = to_clk_mux(hw);
         u32 val;
 
-        val = clk_readl(mux->reg) >> mux->shift;
+        val = clk_mux_readl(mux) >> mux->shift;
         val &= mux->mask;
 
         return clk_mux_val_to_index(hw, mux->table, mux->flags, val);
@@ -94,12 +110,12 @@ static int clk_mux_set_parent(struct clk_hw *hw, u8 index)
         if (mux->flags & CLK_MUX_HIWORD_MASK) {
                 reg = mux->mask << (mux->shift + 16);
         } else {
-                reg = clk_readl(mux->reg);
+                reg = clk_mux_readl(mux);
                 reg &= ~(mux->mask << mux->shift);
         }
         val = val << mux->shift;
         reg |= val;
-        clk_writel(reg, mux->reg);
+        clk_mux_writel(mux, reg);
 
         if (mux->lock)
                 spin_unlock_irqrestore(mux->lock, flags);
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 0bc6d6f80b1a..4ae2257b63c6 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -509,6 +509,9 @@ void clk_hw_unregister_divider(struct clk_hw *hw);
  *      indicate changing mux bits.
  * CLK_MUX_ROUND_CLOSEST - Use the parent rate that is closest to the desired
  *      frequency.
+ * CLK_MUX_BIG_ENDIAN - By default little endian register accesses are used for
+ *      the mux register.  Setting this flag makes the register accesses big
+ *      endian.
  */
 struct clk_mux {
         struct clk_hw   hw;
@@ -527,6 +530,7 @@ struct clk_mux {
 #define CLK_MUX_HIWORD_MASK             BIT(2)
 #define CLK_MUX_READ_ONLY               BIT(3) /* mux can't be changed */
 #define CLK_MUX_ROUND_CLOSEST           BIT(4)
+#define CLK_MUX_BIG_ENDIAN              BIT(5)
 
 extern const struct clk_ops clk_mux_ops;
 extern const struct clk_ops clk_mux_ro_ops;