iio: mma8452: add support for FXLS8471Q

This adds support for Freescale's (now NXP's) FXLS8471Q accelerometer.

We use MMA8451Q's configuration because for what the driver supports,
FXLS8471Q is the same.

Support for FXLS8471Q's features (fast SPI interface and a larger FIFO,
among others) can be added to this driver anytime.

See it's datasheet for the details:
http://cache.nxp.com/files/sensors/doc/data_sheet/FXLS8471Q.pdf

Signed-off-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Documentation/devicetree/bindings/iio/accel/mma8452.txt

@@ -1,4 +1,4 @@
-Freescale MMA8451Q, MMA8452Q, MMA8453Q, MMA8652FC or MMA8653FC
+Freescale MMA8451Q, MMA8452Q, MMA8453Q, MMA8652FC, MMA8653FC or FXLS8471Q
 triaxial accelerometer
 
 Required properties:
@@ -9,6 +9,7 @@ Required properties:
     * "fsl,mma8453"
     * "fsl,mma8652"
     * "fsl,mma8653"
+    * "fsl,fxls8471"
 
   - reg: the I2C address of the chip
 

drivers/iio/accel/Kconfig

@@ -143,7 +143,8 @@ config MMA8452
 	select IIO_TRIGGERED_BUFFER
 	help
 	  Say yes here to build support for the following Freescale 3-axis
-	  accelerometers: MMA8451Q, MMA8452Q, MMA8453Q, MMA8652FC, MMA8653FC.
+	  accelerometers: MMA8451Q, MMA8452Q, MMA8453Q, MMA8652FC, MMA8653FC,
+	  FXLS8471Q.
 
 	  To compile this driver as a module, choose M here: the module
 	  will be called mma8452.

drivers/iio/accel/mma8452.c

@@ -6,6 +6,7 @@
  * MMA8453Q (10 bit)
  * MMA8652FC (12 bit)
  * MMA8653FC (10 bit)
+ * FXLS8471Q (14 bit)
  *
  * Copyright 2015 Martin Kepplinger <martin.kepplinger@theobroma-systems.com>
  * Copyright 2014 Peter Meerwald <pmeerw@pmeerw.net>
@@ -92,6 +93,7 @@
 #define MMA8453_DEVICE_ID			0x3a
 #define MMA8652_DEVICE_ID			0x4a
 #define MMA8653_DEVICE_ID			0x5a
+#define FXLS8471_DEVICE_ID			0x6a
 
 #define MMA8452_AUTO_SUSPEND_DELAY_MS		2000
 
@@ -1055,6 +1057,7 @@ enum {
 	mma8453,
 	mma8652,
 	mma8653,
+	fxls8471,
 };
 
 static const struct mma_chip_info mma_chip_info_table[] = {
@@ -1146,6 +1149,22 @@ static const struct mma_chip_info mma_chip_info_table[] = {
 		.ev_ths_mask = MMA8452_FF_MT_THS_MASK,
 		.ev_count = MMA8452_FF_MT_COUNT,
 	},
+	[fxls8471] = {
+		.chip_id = FXLS8471_DEVICE_ID,
+		.channels = mma8451_channels,
+		.num_channels = ARRAY_SIZE(mma8451_channels),
+		.mma_scales = { {0, 2394}, {0, 4788}, {0, 9577} },
+		.ev_cfg = MMA8452_TRANSIENT_CFG,
+		.ev_cfg_ele = MMA8452_TRANSIENT_CFG_ELE,
+		.ev_cfg_chan_shift = 1,
+		.ev_src = MMA8452_TRANSIENT_SRC,
+		.ev_src_xe = MMA8452_TRANSIENT_SRC_XTRANSE,
+		.ev_src_ye = MMA8452_TRANSIENT_SRC_YTRANSE,
+		.ev_src_ze = MMA8452_TRANSIENT_SRC_ZTRANSE,
+		.ev_ths = MMA8452_TRANSIENT_THS,
+		.ev_ths_mask = MMA8452_TRANSIENT_THS_MASK,
+		.ev_count = MMA8452_TRANSIENT_COUNT,
+	},
 };
 
 static struct attribute *mma8452_attributes[] = {
@@ -1275,6 +1294,7 @@ static const struct of_device_id mma8452_dt_ids[] = {
 	{ .compatible = "fsl,mma8453", .data = &mma_chip_info_table[mma8453] },
 	{ .compatible = "fsl,mma8652", .data = &mma_chip_info_table[mma8652] },
 	{ .compatible = "fsl,mma8653", .data = &mma_chip_info_table[mma8653] },
+	{ .compatible = "fsl,fxls8471", .data = &mma_chip_info_table[fxls8471] },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, mma8452_dt_ids);
@@ -1312,6 +1332,7 @@ static int mma8452_probe(struct i2c_client *client,
 	case MMA8453_DEVICE_ID:
 	case MMA8652_DEVICE_ID:
 	case MMA8653_DEVICE_ID:
+	case FXLS8471_DEVICE_ID:
 		if (ret == data->chip_info->chip_id)
 			break;
 	default:
@@ -1518,6 +1539,7 @@ static const struct i2c_device_id mma8452_id[] = {
 	{ "mma8453", mma8453 },
 	{ "mma8652", mma8652 },
 	{ "mma8653", mma8653 },
+	{ "fxls8471", fxls8471 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, mma8452_id);