From f77620c3f4cfcd1fc97dff9b1af78f2eb7166811 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Wed, 12 Aug 2015 16:13:55 +1000
Subject: [PATCH] mpu6000: check WHOAMI register

this prevents a mpu9250 being seen as a mpu6000
---
 src/drivers/mpu6000/mpu6000.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/drivers/mpu6000/mpu6000.cpp b/src/drivers/mpu6000/mpu6000.cpp
index 288ad579ab..7c7bc43d3e 100644
--- a/src/drivers/mpu6000/mpu6000.cpp
+++ b/src/drivers/mpu6000/mpu6000.cpp
@@ -147,6 +147,8 @@
 #define BIT_I2C_IF_DIS			0x10
 #define BIT_INT_STATUS_DATA		0x01
 
+#define MPU_WHOAMI_6000			0x68
+
 // Product ID Description for MPU6000
 // high 4 bits 	low 4 bits
 // Product Name	Product Revision
@@ -755,6 +757,13 @@ int MPU6000::reset()
 int
 MPU6000::probe()
 {
+	uint8_t whoami;
+	whoami = read_reg(MPUREG_WHOAMI);
+	if (whoami != MPU_WHOAMI_6000) {
+		DEVICE_DEBUG("unexpected WHOAMI 0x%02x", whoami);
+		return -EIO;
+
+	}
 
 	/* look for a product ID we recognise */
 	_product = read_reg(MPUREG_PRODUCT_ID);