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 <[email protected]> Signed-off-by: Stephen Boyd <[email protected]>
jangid · Apr 23, 2019 · 3a72751 · 3a72751
1 parent 9427b71
commit 3a72751
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Showing 2 changed files with 23 additions and 3 deletions.
diff --git 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
@@ -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;