clk: imx: Add correct failure handling for clk based helpers

If the clk_hw based API returns an error, trying to return the clk from
hw will end up in a NULL pointer dereference. So adding the to_clk
checker and using it inside every clk based macro helper we handle that
case correctly.

This to_clk is also temporary and will go away along with the clk based
macro helpers once there is no user that need them anymore.
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

drivers/clk/imx/clk.h

@@ -55,48 +55,48 @@ extern struct imx_pll14xx_clk imx_1443x_pll;
 extern struct imx_pll14xx_clk imx_1443x_dram_pll;
 
 #define imx_clk_cpu(name, parent_name, div, mux, pll, step) \
-	imx_clk_hw_cpu(name, parent_name, div, mux, pll, step)->clk
+	to_clk(imx_clk_hw_cpu(name, parent_name, div, mux, pll, step))
 
 #define clk_register_gate2(dev, name, parent_name, flags, reg, bit_idx, \
 				cgr_val, clk_gate_flags, lock, share_count) \
-	clk_hw_register_gate2(dev, name, parent_name, flags, reg, bit_idx, \
-				cgr_val, clk_gate_flags, lock, share_count)->clk
+	to_clk(clk_hw_register_gate2(dev, name, parent_name, flags, reg, bit_idx, \
+				cgr_val, clk_gate_flags, lock, share_count))
 
 #define imx_clk_pllv3(type, name, parent_name, base, div_mask) \
-	imx_clk_hw_pllv3(type, name, parent_name, base, div_mask)->clk
+	to_clk(imx_clk_hw_pllv3(type, name, parent_name, base, div_mask))
 
 #define imx_clk_pfd(name, parent_name, reg, idx) \
-	imx_clk_hw_pfd(name, parent_name, reg, idx)->clk
+	to_clk(imx_clk_hw_pfd(name, parent_name, reg, idx))
 
 #define imx_clk_gate_exclusive(name, parent, reg, shift, exclusive_mask) \
-	imx_clk_hw_gate_exclusive(name, parent, reg, shift, exclusive_mask)->clk
+	to_clk(imx_clk_hw_gate_exclusive(name, parent, reg, shift, exclusive_mask))
 
 #define imx_clk_fixed_factor(name, parent, mult, div) \
-	imx_clk_hw_fixed_factor(name, parent, mult, div)->clk
+	to_clk(imx_clk_hw_fixed_factor(name, parent, mult, div))
 
 #define imx_clk_divider2(name, parent, reg, shift, width) \
-	imx_clk_hw_divider2(name, parent, reg, shift, width)->clk
+	to_clk(imx_clk_hw_divider2(name, parent, reg, shift, width))
 
 #define imx_clk_gate_dis(name, parent, reg, shift) \
-	imx_clk_hw_gate_dis(name, parent, reg, shift)->clk
+	to_clk(imx_clk_hw_gate_dis(name, parent, reg, shift))
 
 #define imx_clk_gate2(name, parent, reg, shift) \
-	imx_clk_hw_gate2(name, parent, reg, shift)->clk
+	to_clk(imx_clk_hw_gate2(name, parent, reg, shift))
 
 #define imx_clk_gate2_flags(name, parent, reg, shift, flags) \
-	imx_clk_hw_gate2_flags(name, parent, reg, shift, flags)->clk
+	to_clk(imx_clk_hw_gate2_flags(name, parent, reg, shift, flags))
 
 #define imx_clk_gate2_shared2(name, parent, reg, shift, share_count) \
-	imx_clk_hw_gate2_shared2(name, parent, reg, shift, share_count)->clk
+	to_clk(imx_clk_hw_gate2_shared2(name, parent, reg, shift, share_count))
 
 #define imx_clk_gate3(name, parent, reg, shift) \
-	imx_clk_hw_gate3(name, parent, reg, shift)->clk
+	to_clk(imx_clk_hw_gate3(name, parent, reg, shift))
 
 #define imx_clk_gate4(name, parent, reg, shift) \
-	imx_clk_hw_gate4(name, parent, reg, shift)->clk
+	to_clk(imx_clk_hw_gate4(name, parent, reg, shift))
 
 #define imx_clk_mux(name, reg, shift, width, parents, num_parents) \
-	imx_clk_hw_mux(name, reg, shift, width, parents, num_parents)->clk
+	to_clk(imx_clk_hw_mux(name, reg, shift, width, parents, num_parents))
 
 struct clk *imx_clk_pll14xx(const char *name, const char *parent_name,
 		 void __iomem *base, const struct imx_pll14xx_clk *pll_clk);
@@ -199,6 +199,13 @@ struct clk_hw *imx_clk_hw_fixup_mux(const char *name, void __iomem *reg,
 			      u8 shift, u8 width, const char * const *parents,
 			      int num_parents, void (*fixup)(u32 *val));
 
+static inline struct clk *to_clk(struct clk_hw *hw)
+{
+	if (IS_ERR_OR_NULL(hw))
+		return ERR_CAST(hw);
+	return hw->clk;
+}
+
 static inline struct clk *imx_clk_fixed(const char *name, int rate)
 {
 	return clk_register_fixed_rate(NULL, name, NULL, 0, rate);