extcon: max8997: Check the pointer of platform data to protect null pointer error

This patch check the pointer of platform data to protect
kernel panic when platform data is not used and code clean.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
diff --git a/drivers/extcon/extcon-max8997.c b/drivers/extcon/extcon-max8997.c
index e636d95..69641bc 100644
--- a/drivers/extcon/extcon-max8997.c
+++ b/drivers/extcon/extcon-max8997.c
@@ -712,29 +712,45 @@
 		goto err_irq;
 	}
 
-	/* Initialize registers according to platform data */
 	if (pdata->muic_pdata) {
-		struct max8997_muic_platform_data *mdata = info->muic_pdata;
+		struct max8997_muic_platform_data *muic_pdata
+			= pdata->muic_pdata;
 
-		for (i = 0; i < mdata->num_init_data; i++) {
-			max8997_write_reg(info->muic, mdata->init_data[i].addr,
-					mdata->init_data[i].data);
+		/* Initialize registers according to platform data */
+		for (i = 0; i < muic_pdata->num_init_data; i++) {
+			max8997_write_reg(info->muic,
+					muic_pdata->init_data[i].addr,
+					muic_pdata->init_data[i].data);
 		}
-	}
 
-	/*
-	 * Default usb/uart path whether UART/USB or AUX_UART/AUX_USB
-	 * h/w path of COMP2/COMN1 on CONTROL1 register.
-	 */
-	if (pdata->muic_pdata->path_uart)
-		info->path_uart = pdata->muic_pdata->path_uart;
-	else
+		/*
+		 * Default usb/uart path whether UART/USB or AUX_UART/AUX_USB
+		 * h/w path of COMP2/COMN1 on CONTROL1 register.
+		 */
+		if (muic_pdata->path_uart)
+			info->path_uart = muic_pdata->path_uart;
+		else
+			info->path_uart = CONTROL1_SW_UART;
+
+		if (muic_pdata->path_usb)
+			info->path_usb = muic_pdata->path_usb;
+		else
+			info->path_usb = CONTROL1_SW_USB;
+
+		/*
+		 * Default delay time for detecting cable state
+		 * after certain time.
+		 */
+		if (muic_pdata->detcable_delay_ms)
+			delay_jiffies =
+				msecs_to_jiffies(muic_pdata->detcable_delay_ms);
+		else
+			delay_jiffies = msecs_to_jiffies(DELAY_MS_DEFAULT);
+	} else {
 		info->path_uart = CONTROL1_SW_UART;
-
-	if (pdata->muic_pdata->path_usb)
-		info->path_usb = pdata->muic_pdata->path_usb;
-	else
 		info->path_usb = CONTROL1_SW_USB;
+		delay_jiffies = msecs_to_jiffies(DELAY_MS_DEFAULT);
+	}
 
 	/* Set initial path for UART */
 	 max8997_muic_set_path(info, info->path_uart, true);
@@ -751,10 +767,6 @@
 	 * driver should notify cable state to upper layer.
 	 */
 	INIT_DELAYED_WORK(&info->wq_detcable, max8997_muic_detect_cable_wq);
-	if (pdata->muic_pdata->detcable_delay_ms)
-		delay_jiffies = msecs_to_jiffies(pdata->muic_pdata->detcable_delay_ms);
-	else
-		delay_jiffies = msecs_to_jiffies(DELAY_MS_DEFAULT);
 	schedule_delayed_work(&info->wq_detcable, delay_jiffies);
 
 	return 0;