i2c: sh_mobile: allow setup callback to return errno

The setup callback will be more generic and, thus, need to be able to
return error codes. Change the return type to 'int' for that.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index 1ac896e..a3a377a 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -149,7 +149,7 @@
 
 struct sh_mobile_dt_config {
 	int clks_per_count;
-	void (*setup)(struct sh_mobile_i2c_data *pd);
+	int (*setup)(struct sh_mobile_i2c_data *pd);
 };
 
 #define IIC_FLAG_HAS_ICIC67	(1 << 0)
@@ -749,7 +749,7 @@
  * r8a7740 chip has lasting errata on I2C I/O pad reset.
  * this is work-around for it.
  */
-static void sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd)
+static int sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd)
 {
 	iic_set_clr(pd, ICCR, ICCR_ICE, 0);
 	iic_rd(pd, ICCR); /* dummy read */
@@ -770,6 +770,8 @@
 	udelay(10);
 	iic_wr(pd, ICCR, ICCR_TRS);
 	udelay(10);
+
+	return 0;
 }
 
 static const struct sh_mobile_dt_config default_dt_config = {
@@ -881,8 +883,11 @@
 	if (config) {
 		pd->clks_per_count = config->clks_per_count;
 
-		if (config->setup)
-			config->setup(pd);
+		if (config->setup) {
+			ret = config->setup(pd);
+			if (ret)
+				return ret;
+		}
 	}
 
 	ret = sh_mobile_i2c_init(pd);