clk: qcom: Fix clk_get_parent function return value

According to the common clock framework API, the clk_get_parent() function
should return u8. Currently we are returning negative values on error. Fix
this and use the default parent in case of an error.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
diff --git a/drivers/clk/qcom/clk-rcg.c b/drivers/clk/qcom/clk-rcg.c
index 466f30c..59a093e 100644
--- a/drivers/clk/qcom/clk-rcg.c
+++ b/drivers/clk/qcom/clk-rcg.c
@@ -47,15 +47,20 @@
 	struct clk_rcg *rcg = to_clk_rcg(hw);
 	int num_parents = __clk_get_num_parents(hw->clk);
 	u32 ns;
-	int i;
+	int i, ret;
 
-	regmap_read(rcg->clkr.regmap, rcg->ns_reg, &ns);
+	ret = regmap_read(rcg->clkr.regmap, rcg->ns_reg, &ns);
+	if (ret)
+		goto err;
 	ns = ns_to_src(&rcg->s, ns);
 	for (i = 0; i < num_parents; i++)
 		if (ns == rcg->s.parent_map[i])
 			return i;
 
-	return -EINVAL;
+err:
+	pr_debug("%s: Clock %s has invalid parent, using default.\n",
+		 __func__, __clk_get_name(hw->clk));
+	return 0;
 }
 
 static int reg_to_bank(struct clk_dyn_rcg *rcg, u32 bank)
@@ -70,21 +75,28 @@
 	int num_parents = __clk_get_num_parents(hw->clk);
 	u32 ns, reg;
 	int bank;
-	int i;
+	int i, ret;
 	struct src_sel *s;
 
-	regmap_read(rcg->clkr.regmap, rcg->bank_reg, &reg);
+	ret = regmap_read(rcg->clkr.regmap, rcg->bank_reg, &reg);
+	if (ret)
+		goto err;
 	bank = reg_to_bank(rcg, reg);
 	s = &rcg->s[bank];
 
-	regmap_read(rcg->clkr.regmap, rcg->ns_reg[bank], &ns);
+	ret = regmap_read(rcg->clkr.regmap, rcg->ns_reg[bank], &ns);
+	if (ret)
+		goto err;
 	ns = ns_to_src(s, ns);
 
 	for (i = 0; i < num_parents; i++)
 		if (ns == s->parent_map[i])
 			return i;
 
-	return -EINVAL;
+err:
+	pr_debug("%s: Clock %s has invalid parent, using default.\n",
+		 __func__, __clk_get_name(hw->clk));
+	return 0;
 }
 
 static int clk_rcg_set_parent(struct clk_hw *hw, u8 index)