mfd: 88pm80x: Change chip id definition and detection

Change the chip id definition and detection and then:

1. We no longer need to add PM800_CHIP_XXX for the coming revision.
2. We no longer need to pass driver_data in i2c_device_id as we
   can distinguish the chips from the CHIP_ID register.

Signed-off-by: Chao Xie <chao.xie@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/88pm80x.c b/drivers/mfd/88pm80x.c
index f736a46..5e72f65 100644
--- a/drivers/mfd/88pm80x.c
+++ b/drivers/mfd/88pm80x.c
@@ -18,6 +18,23 @@
 #include <linux/uaccess.h>
 #include <linux/err.h>
 
+/* 88pm80x chips have same definition for chip id register. */
+#define PM80X_CHIP_ID			(0x00)
+#define PM80X_CHIP_ID_NUM(x)		(((x) >> 5) & 0x7)
+#define PM80X_CHIP_ID_REVISION(x)	((x) & 0x1F)
+
+struct pm80x_chip_mapping {
+	unsigned int	id;
+	int		type;
+};
+
+static struct pm80x_chip_mapping chip_mapping[] = {
+	/* 88PM800 chip id number */
+	{0x3,	CHIP_PM800},
+	/* 88PM805 chip id number */
+	{0x0,	CHIP_PM805},
+};
+
 /*
  * workaround: some registers needed by pm805 are defined in pm800, so
  * need to use this global variable to maintain the relation between
@@ -31,12 +48,13 @@
 };
 EXPORT_SYMBOL_GPL(pm80x_regmap_config);
 
-int pm80x_init(struct i2c_client *client,
-				 const struct i2c_device_id *id)
+
+int pm80x_init(struct i2c_client *client)
 {
 	struct pm80x_chip *chip;
 	struct regmap *map;
-	int ret = 0;
+	unsigned int val;
+	int i, ret = 0;
 
 	chip =
 	    devm_kzalloc(&client->dev, sizeof(struct pm80x_chip), GFP_KERNEL);
@@ -51,10 +69,6 @@
 		return ret;
 	}
 
-	chip->id = id->driver_data;
-	if (chip->id < CHIP_PM800 || chip->id > CHIP_PM805)
-		return -EINVAL;
-
 	chip->client = client;
 	chip->regmap = map;
 
@@ -64,6 +78,25 @@
 	dev_set_drvdata(chip->dev, chip);
 	i2c_set_clientdata(chip->client, chip);
 
+	ret = regmap_read(chip->regmap, PM80X_CHIP_ID, &val);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to read CHIP ID: %d\n", ret);
+		return ret;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(chip_mapping); i++) {
+		if (chip_mapping[i].id == PM80X_CHIP_ID_NUM(val)) {
+			chip->type = chip_mapping[i].type;
+			break;
+		}
+	}
+
+	if (i == ARRAY_SIZE(chip_mapping)) {
+		dev_err(chip->dev,
+			"Failed to detect Marvell 88PM800:ChipID[0x%x]\n", val);
+		return -EINVAL;
+	}
+
 	device_init_wakeup(&client->dev, 1);
 
 	/*