mfd: MAX77693: Fix NULL pointer error when initializing irqs

This patch initialize register map of MUIC device because mfd driver
of Maxim MAX77693 use regmap-muic instance of MUIC device when irqs of
Maxim MAX77693 is initialized before call max77693-muic probe() function.
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reported-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/extcon/extcon-max77693.c

@@ -669,13 +669,18 @@ static int __devinit max77693_muic_probe(struct platform_device *pdev)
 	}
 	info->dev = &pdev->dev;
 	info->max77693 = max77693;
-	info->max77693->regmap_muic = regmap_init_i2c(info->max77693->muic,
-					 &max77693_muic_regmap_config);
-	if (IS_ERR(info->max77693->regmap_muic)) {
-		ret = PTR_ERR(info->max77693->regmap_muic);
-		dev_err(max77693->dev,
-			"failed to allocate register map: %d\n", ret);
-		goto err_regmap;
+	if (info->max77693->regmap_muic)
+		dev_dbg(&pdev->dev, "allocate register map\n");
+	else {
+		info->max77693->regmap_muic = devm_regmap_init_i2c(
+						info->max77693->muic,
+						&max77693_muic_regmap_config);
+		if (IS_ERR(info->max77693->regmap_muic)) {
+			ret = PTR_ERR(info->max77693->regmap_muic);
+			dev_err(max77693->dev,
+				"failed to allocate register map: %d\n", ret);
+			goto err_regmap;
+		}
 	}
 	platform_set_drvdata(pdev, info);
 	mutex_init(&info->mutex);

drivers/mfd/max77693.c

@@ -152,6 +152,20 @@ static int max77693_i2c_probe(struct i2c_client *i2c,
 	max77693->haptic = i2c_new_dummy(i2c->adapter, I2C_ADDR_HAPTIC);
 	i2c_set_clientdata(max77693->haptic, max77693);
 
+	/*
+	 * Initialize register map for MUIC device because use regmap-muic
+	 * instance of MUIC device when irq of max77693 is initialized
+	 * before call max77693-muic probe() function.
+	 */
+	max77693->regmap_muic = devm_regmap_init_i2c(max77693->muic,
+					 &max77693_regmap_config);
+	if (IS_ERR(max77693->regmap_muic)) {
+		ret = PTR_ERR(max77693->regmap_muic);
+		dev_err(max77693->dev,
+			"failed to allocate register map: %d\n", ret);
+		goto err_regmap;
+	}
+
 	ret = max77693_irq_init(max77693);
 	if (ret < 0)
 		goto err_irq;