iio: imu: mpu6050: Fix FIFO layout for ICM20602

[ Upstream commit 1615fe41a1959a2ee2814ba62736b2bb54e9802a ]

The MPU6050 driver has recently gained support for the
ICM20602 IMU, which is very similar to MPU6xxx. However,
the ICM20602's FIFO data specifically includes temperature
readings, which were not present on MPU6xxx parts. As a
result, the driver will under-read the ICM20602's FIFO
register, causing the same (partial) sample to be returned
for all reads, until the FIFO overflows.

Fix this by adding a table of scan elements specifically
for the ICM20602, which takes the extra temperature data
into consideration.

While we're at it, fix the temperature offset and scaling
on ICM20602, since it uses different scale/offset constants
than the rest of the MPU6xxx devices.

Signed-off-by: Steve Moskovchenko <stevemo@skydio.com>
Fixes: 22904bdff978 ("iio: imu: mpu6050: Add support for the ICM 20602 IMU")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
index ea099523e0355cab124c6ec929880a4ea3dd22d9..baba8e5459d00a0bd119b84ce1ff596b243e7626 100644 (file)
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -479,7 +479,10 @@ inv_mpu6050_read_raw(struct iio_dev *indio_dev,
                        return IIO_VAL_INT_PLUS_MICRO;
                case IIO_TEMP:
                        *val = 0;
-                       *val2 = INV_MPU6050_TEMP_SCALE;
+                       if (st->chip_type == INV_ICM20602)
+                               *val2 = INV_ICM20602_TEMP_SCALE;
+                       else
+                               *val2 = INV_MPU6050_TEMP_SCALE;
 
                        return IIO_VAL_INT_PLUS_MICRO;
                default:
@@ -488,7 +491,10 @@ inv_mpu6050_read_raw(struct iio_dev *indio_dev,
        case IIO_CHAN_INFO_OFFSET:
                switch (chan->type) {
                case IIO_TEMP:
-                       *val = INV_MPU6050_TEMP_OFFSET;
+                       if (st->chip_type == INV_ICM20602)
+                               *val = INV_ICM20602_TEMP_OFFSET;
+                       else
+                               *val = INV_MPU6050_TEMP_OFFSET;
 
                        return IIO_VAL_INT;
                default:
@@ -853,6 +859,32 @@ static const struct iio_chan_spec inv_mpu_channels[] = {
        INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_Z, INV_MPU6050_SCAN_ACCL_Z),
 };
 
+static const struct iio_chan_spec inv_icm20602_channels[] = {
+       IIO_CHAN_SOFT_TIMESTAMP(INV_ICM20602_SCAN_TIMESTAMP),
+       {
+               .type = IIO_TEMP,
+               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW)
+                               | BIT(IIO_CHAN_INFO_OFFSET)
+                               | BIT(IIO_CHAN_INFO_SCALE),
+               .scan_index = INV_ICM20602_SCAN_TEMP,
+               .scan_type = {
+                               .sign = 's',
+                               .realbits = 16,
+                               .storagebits = 16,
+                               .shift = 0,
+                               .endianness = IIO_BE,
+                            },
+       },
+
+       INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_X, INV_ICM20602_SCAN_GYRO_X),
+       INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_Y, INV_ICM20602_SCAN_GYRO_Y),
+       INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_Z, INV_ICM20602_SCAN_GYRO_Z),
+
+       INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_Y, INV_ICM20602_SCAN_ACCL_Y),
+       INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_X, INV_ICM20602_SCAN_ACCL_X),
+       INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_Z, INV_ICM20602_SCAN_ACCL_Z),
+};
+
 /*
  * The user can choose any frequency between INV_MPU6050_MIN_FIFO_RATE and
  * INV_MPU6050_MAX_FIFO_RATE, but only these frequencies are matched by the
@@ -1053,8 +1085,14 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
                indio_dev->name = name;
        else
                indio_dev->name = dev_name(dev);
-       indio_dev->channels = inv_mpu_channels;
-       indio_dev->num_channels = ARRAY_SIZE(inv_mpu_channels);
+
+       if (chip_type == INV_ICM20602) {
+               indio_dev->channels = inv_icm20602_channels;
+               indio_dev->num_channels = ARRAY_SIZE(inv_icm20602_channels);
+       } else {
+               indio_dev->channels = inv_mpu_channels;
+               indio_dev->num_channels = ARRAY_SIZE(inv_mpu_channels);
+       }
 
        indio_dev->info = &mpu_info;
        indio_dev->modes = INDIO_BUFFER_TRIGGERED;

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
index e56c1d191ae4605ffe3c942e4744d6cce609e107..6ef872f97c175ceb0f660fc5b1e316524676d6f8 100644 (file)
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
@@ -208,6 +208,9 @@ struct inv_mpu6050_state {
 #define INV_MPU6050_BYTES_PER_3AXIS_SENSOR   6
 #define INV_MPU6050_FIFO_COUNT_BYTE          2
 
+/* ICM20602 FIFO samples include temperature readings */
+#define INV_ICM20602_BYTES_PER_TEMP_SENSOR   2
+
 /* mpu6500 registers */
 #define INV_MPU6500_REG_ACCEL_CONFIG_2      0x1D
 #define INV_MPU6500_REG_ACCEL_OFFSET        0x77
@@ -229,6 +232,9 @@ struct inv_mpu6050_state {
 #define INV_MPU6050_GYRO_CONFIG_FSR_SHIFT    3
 #define INV_MPU6050_ACCL_CONFIG_FSR_SHIFT    3
 
+#define INV_ICM20602_TEMP_OFFSET            8170
+#define INV_ICM20602_TEMP_SCALE                     3060
+
 /* 6 + 6 round up and plus 8 */
 #define INV_MPU6050_OUTPUT_DATA_SIZE         24
 
@@ -270,7 +276,7 @@ struct inv_mpu6050_state {
 #define INV_ICM20608_WHOAMI_VALUE              0xAF
 #define INV_ICM20602_WHOAMI_VALUE              0x12
 
-/* scan element definition */
+/* scan element definition for generic MPU6xxx devices */
 enum inv_mpu6050_scan {
        INV_MPU6050_SCAN_ACCL_X,
        INV_MPU6050_SCAN_ACCL_Y,
@@ -281,6 +287,18 @@ enum inv_mpu6050_scan {
        INV_MPU6050_SCAN_TIMESTAMP,
 };
 
+/* scan element definition for ICM20602, which includes temperature */
+enum inv_icm20602_scan {
+       INV_ICM20602_SCAN_ACCL_X,
+       INV_ICM20602_SCAN_ACCL_Y,
+       INV_ICM20602_SCAN_ACCL_Z,
+       INV_ICM20602_SCAN_TEMP,
+       INV_ICM20602_SCAN_GYRO_X,
+       INV_ICM20602_SCAN_GYRO_Y,
+       INV_ICM20602_SCAN_GYRO_Z,
+       INV_ICM20602_SCAN_TIMESTAMP,
+};
+
 enum inv_mpu6050_filter_e {
        INV_MPU6050_FILTER_256HZ_NOLPF2 = 0,
        INV_MPU6050_FILTER_188HZ,

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
index 4f9c2765aa23f4ba556e7b3976627c497d73c93e..0e54f2d54bd70cc75815dbf2f7c2c7a33eaad2a2 100644 (file)
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
@@ -204,6 +204,9 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
        if (st->chip_config.gyro_fifo_enable)
                bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR;
 
+       if (st->chip_type == INV_ICM20602)
+               bytes_per_datum += INV_ICM20602_BYTES_PER_TEMP_SENSOR;
+
        /*
         * read fifo_count register to know how many bytes are inside the FIFO
         * right now