iio: imu: inv_mpu6050: add support of MPU9150 magnetometer

Add support for driving MPU9150 magnetometer (AK8975) from mpu.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/inv_mpu6050/inv_mpu_core.c

@@ -914,6 +914,33 @@ static const unsigned long inv_mpu_scan_masks[] = {
 		.ext_info = inv_ext_info,				\
 	}
 
+static const struct iio_chan_spec inv_mpu9150_channels[] = {
+	IIO_CHAN_SOFT_TIMESTAMP(INV_MPU9X50_SCAN_TIMESTAMP),
+	/*
+	 * Note that temperature should only be via polled reading only,
+	 * not the final scan elements output.
+	 */
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW)
+				| BIT(IIO_CHAN_INFO_OFFSET)
+				| BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = -1,
+	},
+	INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_X, INV_MPU6050_SCAN_GYRO_X),
+	INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_Y, INV_MPU6050_SCAN_GYRO_Y),
+	INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_Z, INV_MPU6050_SCAN_GYRO_Z),
+
+	INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_X, INV_MPU6050_SCAN_ACCL_X),
+	INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_Y, INV_MPU6050_SCAN_ACCL_Y),
+	INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_Z, INV_MPU6050_SCAN_ACCL_Z),
+
+	/* Magnetometer resolution is 13 bits */
+	INV_MPU9X50_MAGN_CHAN(IIO_MOD_X, 13, INV_MPU9X50_SCAN_MAGN_X),
+	INV_MPU9X50_MAGN_CHAN(IIO_MOD_Y, 13, INV_MPU9X50_SCAN_MAGN_Y),
+	INV_MPU9X50_MAGN_CHAN(IIO_MOD_Z, 13, INV_MPU9X50_SCAN_MAGN_Z),
+};
+
 static const struct iio_chan_spec inv_mpu9250_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(INV_MPU9X50_SCAN_TIMESTAMP),
 	/*
@@ -1323,21 +1350,16 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
 		inv_mpu_bus_setup(indio_dev);
 
 	switch (chip_type) {
+	case INV_MPU9150:
+		indio_dev->channels = inv_mpu9150_channels;
+		indio_dev->num_channels = ARRAY_SIZE(inv_mpu9150_channels);
+		indio_dev->available_scan_masks = inv_mpu9x50_scan_masks;
+		break;
 	case INV_MPU9250:
 	case INV_MPU9255:
-		/*
-		 * Use magnetometer inside the chip only if there is no i2c
-		 * auxiliary device in use.
-		 */
-		if (!st->magn_disabled) {
-			indio_dev->channels = inv_mpu9250_channels;
-			indio_dev->num_channels = ARRAY_SIZE(inv_mpu9250_channels);
-			indio_dev->available_scan_masks = inv_mpu9x50_scan_masks;
-		} else {
-			indio_dev->channels = inv_mpu_channels;
-			indio_dev->num_channels = ARRAY_SIZE(inv_mpu_channels);
-			indio_dev->available_scan_masks = inv_mpu_scan_masks;
-		}
+		indio_dev->channels = inv_mpu9250_channels;
+		indio_dev->num_channels = ARRAY_SIZE(inv_mpu9250_channels);
+		indio_dev->available_scan_masks = inv_mpu9x50_scan_masks;
 		break;
 	case INV_ICM20602:
 		indio_dev->channels = inv_icm20602_channels;
@@ -1350,6 +1372,15 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
 		indio_dev->available_scan_masks = inv_mpu_scan_masks;
 		break;
 	}
+	/*
+	 * Use magnetometer inside the chip only if there is no i2c
+	 * auxiliary device in use. Otherwise Going back to 6-axis only.
+	 */
+	if (st->magn_disabled) {
+		indio_dev->channels = inv_mpu_channels;
+		indio_dev->num_channels = ARRAY_SIZE(inv_mpu_channels);
+		indio_dev->available_scan_masks = inv_mpu_scan_masks;
+	}
 
 	indio_dev->info = &mpu_info;
 	indio_dev->modes = INDIO_BUFFER_TRIGGERED;

drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c

@@ -77,6 +77,7 @@ static bool inv_mpu_i2c_aux_bus(struct device *dev)
 	case INV_ICM20602:
 		/* no i2c auxiliary bus on the chip */
 		return false;
+	case INV_MPU9150:
 	case INV_MPU9250:
 	case INV_MPU9255:
 		if (st->magn_disabled)
@@ -102,6 +103,7 @@ static int inv_mpu_magn_disable(struct iio_dev *indio_dev)
 	struct device_node *mux_node;
 
 	switch (st->chip_type) {
+	case INV_MPU9150:
 	case INV_MPU9250:
 	case INV_MPU9255:
 		mux_node = of_get_child_by_name(dev->of_node, "i2c-gate");

drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c

@@ -12,7 +12,9 @@
 #include "inv_mpu_magn.h"
 
 /*
- * MPU9250 magnetometer is an AKM AK8963 chip on I2C aux bus
+ * MPU9xxx magnetometer are AKM chips on I2C aux bus
+ * MPU9150 is AK8975
+ * MPU9250 is AK8963
  */
 #define INV_MPU_MAGN_I2C_ADDR		0x0C
 
@@ -33,10 +35,10 @@
 #define INV_MPU_MAGN_BITS_MODE_PWDN	0x00
 #define INV_MPU_MAGN_BITS_MODE_SINGLE	0x01
 #define INV_MPU_MAGN_BITS_MODE_FUSE	0x0F
-#define INV_MPU_MAGN_BIT_OUTPUT_BIT	0x10
+#define INV_MPU9250_MAGN_BIT_OUTPUT_BIT	0x10
 
-#define INV_MPU_MAGN_REG_CNTL2		0x0B
-#define INV_MPU_MAGN_BIT_SRST		0x01
+#define INV_MPU9250_MAGN_REG_CNTL2	0x0B
+#define INV_MPU9250_MAGN_BIT_SRST	0x01
 
 #define INV_MPU_MAGN_REG_ASAX		0x10
 #define INV_MPU_MAGN_REG_ASAY		0x11
@@ -48,6 +50,7 @@
 static bool inv_magn_supported(const struct inv_mpu6050_state *st)
 {
 	switch (st->chip_type) {
+	case INV_MPU9150:
 	case INV_MPU9250:
 	case INV_MPU9255:
 		return true;
@@ -61,6 +64,7 @@ static int inv_magn_init(struct inv_mpu6050_state *st)
 {
 	uint8_t val;
 	uint8_t asa[3];
+	int32_t sensitivity;
 	int ret;
 
 	/* check whoami */
@@ -71,12 +75,19 @@ static int inv_magn_init(struct inv_mpu6050_state *st)
 	if (val != INV_MPU_MAGN_BITS_WIA)
 		return -ENODEV;
 
-	/* reset chip */
-	ret = inv_mpu_aux_write(st, INV_MPU_MAGN_I2C_ADDR,
-				INV_MPU_MAGN_REG_CNTL2,
-				INV_MPU_MAGN_BIT_SRST);
-	if (ret)
-		return ret;
+	/* software reset for MPU925x only */
+	switch (st->chip_type) {
+	case INV_MPU9250:
+	case INV_MPU9255:
+		ret = inv_mpu_aux_write(st, INV_MPU_MAGN_I2C_ADDR,
+					INV_MPU9250_MAGN_REG_CNTL2,
+					INV_MPU9250_MAGN_BIT_SRST);
+		if (ret)
+			return ret;
+		break;
+	default:
+		break;
+	}
 
 	/* read fuse ROM data */
 	ret = inv_mpu_aux_write(st, INV_MPU_MAGN_I2C_ADDR,
@@ -97,6 +108,25 @@ static int inv_magn_init(struct inv_mpu6050_state *st)
 	if (ret)
 		return ret;
 
+	/*
+	 * Sensor sentivity
+	 * 1 uT = 0.01 G and value is in micron (1e6)
+	 * sensitvity = x uT * 0.01 * 1e6
+	 */
+	switch (st->chip_type) {
+	case INV_MPU9150:
+		/* sensor sensitivity is 0.3 uT */
+		sensitivity = 3000;
+		break;
+	case INV_MPU9250:
+	case INV_MPU9255:
+		/* sensor sensitivity in 16 bits mode: 0.15 uT */
+		sensitivity = 1500;
+		break;
+	default:
+		return -EINVAL;
+	}
+
 	/*
 	 * Sensitivity adjustement and scale to Gauss
 	 *
@@ -104,16 +134,11 @@ static int inv_magn_init(struct inv_mpu6050_state *st)
 	 * Factor simplification:
 	 * Hadj = H * ((ASA + 128) / 256)
 	 *
-	 * Sensor sentivity
-	 * 0.15 uT in 16 bits mode
-	 * 1 uT = 0.01 G and value is in micron (1e6)
-	 * sensitvity = 0.15 uT * 0.01 * 1e6
-	 *
-	 * raw_to_gauss = Hadj * 1500
+	 * raw_to_gauss = Hadj * sensitivity
 	 */
-	st->magn_raw_to_gauss[0] = (((int32_t)asa[0] + 128) * 1500) / 256;
-	st->magn_raw_to_gauss[1] = (((int32_t)asa[1] + 128) * 1500) / 256;
-	st->magn_raw_to_gauss[2] = (((int32_t)asa[2] + 128) * 1500) / 256;
+	st->magn_raw_to_gauss[0] = (((int32_t)asa[0] + 128) * sensitivity) / 256;
+	st->magn_raw_to_gauss[1] = (((int32_t)asa[1] + 128) * sensitivity) / 256;
+	st->magn_raw_to_gauss[2] = (((int32_t)asa[2] + 128) * sensitivity) / 256;
 
 	return 0;
 }
@@ -129,6 +154,7 @@ static int inv_magn_init(struct inv_mpu6050_state *st)
  */
 int inv_mpu_magn_probe(struct inv_mpu6050_state *st)
 {
+	uint8_t val;
 	int ret;
 
 	/* quit if chip is not supported */
@@ -179,10 +205,17 @@ int inv_mpu_magn_probe(struct inv_mpu6050_state *st)
 	if (ret)
 		return ret;
 
-	/* add 16 bits mode */
-	ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_DO(1),
-			   INV_MPU_MAGN_BITS_MODE_SINGLE |
-			   INV_MPU_MAGN_BIT_OUTPUT_BIT);
+	/* add 16 bits mode for MPU925x */
+	val = INV_MPU_MAGN_BITS_MODE_SINGLE;
+	switch (st->chip_type) {
+	case INV_MPU9250:
+	case INV_MPU9255:
+		val |= INV_MPU9250_MAGN_BIT_OUTPUT_BIT;
+		break;
+	default:
+		break;
+	}
+	ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_DO(1), val);
 	if (ret)
 		return ret;
 
@@ -237,6 +270,7 @@ int inv_mpu_magn_set_orient(struct inv_mpu6050_state *st)
 
 	/* fill magnetometer orientation */
 	switch (st->chip_type) {
+	case INV_MPU9150:
 	case INV_MPU9250:
 	case INV_MPU9255:
 		/* x <- y */

drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c

@@ -50,6 +50,7 @@ static void inv_scan_query(struct iio_dev *indio_dev)
 	struct inv_mpu6050_state *st = iio_priv(indio_dev);
 
 	switch (st->chip_type) {
+	case INV_MPU9150:
 	case INV_MPU9250:
 	case INV_MPU9255:
 		return inv_scan_query_mpu9x50(indio_dev);