mtd: mtdchar: handle chips that have user otp but no factory otp

Before this patch mtd_read_fact_prot_reg was used to check availability
for both MTD_OTP_FACTORY and MTD_OTP_USER access. This made accessing
user otp for chips that don't have a factory otp area impossible. So use
the right wrapper depending on the intended area to be accessed.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/mtdchar.c

@@ -370,28 +370,30 @@ static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 {
 	struct mtd_info *mtd = mfi->mtd;
 	size_t retlen;
-	int ret = 0;
-
-	/*
-	 * Make a fake call to mtd_read_fact_prot_reg() to check if OTP
-	 * operations are supported.
-	 */
-	if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) == -EOPNOTSUPP)
-		return -EOPNOTSUPP;
 
 	switch (mode) {
 	case MTD_OTP_FACTORY:
+		if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
+				-EOPNOTSUPP)
+			return -EOPNOTSUPP;
+
 		mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 		break;
 	case MTD_OTP_USER:
+		if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
+				-EOPNOTSUPP)
+			return -EOPNOTSUPP;
+
 		mfi->mode = MTD_FILE_MODE_OTP_USER;
 		break;
-	default:
-		ret = -EINVAL;
 	case MTD_OTP_OFF:
+		mfi->mode = MTD_FILE_MODE_NORMAL;
 		break;
+	default:
+		return -EINVAL;
 	}
-	return ret;
+
+	return 0;
 }
 #else
 # define otp_select_filemode(f,m)	-EOPNOTSUPP