Instead of storing fifo rate in Hz, store the chip internal sample
rate divider. This will be more useful for timestamping. There
are both equivalent.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@xxxxxxxxxxxxxx>
---
drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 18 +++++++++++-------
drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h | 16 +++++++++++++---
2 files changed, 24 insertions(+), 10 deletions(-)
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
index 1e7e750294fc..2c3e666aa970 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -82,7 +82,7 @@ static const struct inv_mpu6050_reg_map reg_set_6050 = {
static const struct inv_mpu6050_chip_config chip_config_6050 = {
.fsr = INV_MPU6050_FSR_2000DPS,
.lpf = INV_MPU6050_FILTER_20HZ,
- .fifo_rate = INV_MPU6050_INIT_FIFO_RATE,
+ .divider = INV_MPU6050_FIFO_RATE_TO_DIVIDER(INV_MPU6050_INIT_FIFO_RATE),
.gyro_fifo_enable = false,
.accl_fifo_enable = false,
.accl_fs = INV_MPU6050_FS_02G,
@@ -278,7 +278,7 @@ static int inv_mpu6050_init_config(struct iio_dev *indio_dev)
if (result)
goto error_power_off;
- d = INV_MPU6050_ONE_K_HZ / INV_MPU6050_INIT_FIFO_RATE - 1;
+ d = INV_MPU6050_FIFO_RATE_TO_DIVIDER(INV_MPU6050_INIT_FIFO_RATE);
result = regmap_write(st->map, st->reg->sample_rate_div, d);
if (result)
goto error_power_off;
@@ -628,7 +628,7 @@ static ssize_t
inv_mpu6050_fifo_rate_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
- s32 fifo_rate;
+ int fifo_rate;
u8 d;
int result;
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
@@ -644,8 +644,13 @@ inv_mpu6050_fifo_rate_store(struct device *dev, struct device_attribute *attr,
if (result)
return result;
+ /* compute the chip sample rate divider */
+ d = INV_MPU6050_FIFO_RATE_TO_DIVIDER(fifo_rate);
+ /* compute back the fifo rate to handle truncation cases */
+ fifo_rate = INV_MPU6050_DIVIDER_TO_FIFO_RATE(d);
+
mutex_lock(&st->lock);
- if (fifo_rate == st->chip_config.fifo_rate) {
+ if (d == st->chip_config.divider) {
result = 0;
goto fifo_rate_fail_unlock;
}
@@ -653,11 +658,10 @@ inv_mpu6050_fifo_rate_store(struct device *dev, struct device_attribute *attr,
if (result)
goto fifo_rate_fail_unlock;
- d = INV_MPU6050_ONE_K_HZ / fifo_rate - 1;
result = regmap_write(st->map, st->reg->sample_rate_div, d);
if (result)
goto fifo_rate_fail_power_off;
- st->chip_config.fifo_rate = fifo_rate;
+ st->chip_config.divider = d;
result = inv_mpu6050_set_lpf(st, fifo_rate);
if (result)
@@ -685,7 +689,7 @@ inv_fifo_rate_show(struct device *dev, struct device_attribute *attr,
unsigned fifo_rate;
mutex_lock(&st->lock);
- fifo_rate = st->chip_config.fifo_rate;
+ fifo_rate = INV_MPU6050_DIVIDER_TO_FIFO_RATE(st->chip_config.divider);
mutex_unlock(&st->lock);
return scnprintf(buf, PAGE_SIZE, "%u\n", fifo_rate);
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
index a92ddd45586c..a1130b9a420c 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
@@ -86,7 +86,7 @@ enum inv_devices {
* @accl_fs: accel full scale range.
* @accl_fifo_enable: enable accel data output
* @gyro_fifo_enable: enable gyro data output
- * @fifo_rate: FIFO update rate.
+ * @divider: chip sample rate divider (sample rate divider - 1)
*/
struct inv_mpu6050_chip_config {
unsigned int fsr:2;
@@ -94,7 +94,7 @@ struct inv_mpu6050_chip_config {
unsigned int accl_fs:2;
unsigned int accl_fifo_enable:1;
unsigned int gyro_fifo_enable:1;
- u16 fifo_rate;
+ u8 divider;
u8 user_ctrl;
};
@@ -228,7 +228,17 @@ struct inv_mpu6050_state {
#define INV_MPU6050_INIT_FIFO_RATE 50
#define INV_MPU6050_MAX_FIFO_RATE 1000
#define INV_MPU6050_MIN_FIFO_RATE 4
-#define INV_MPU6050_ONE_K_HZ 1000
+
+/* chip internal frequency: 1KHz */
+#define INV_MPU6050_INTERNAL_FREQ_HZ 1000
+/* return the frequency divider (chip sample rate divider + 1) */
+#define INV_MPU6050_FREQ_DIVIDER(st) \
+ ((st)->chip_config.divider + 1)
+/* chip sample rate divider to fifo rate */
+#define INV_MPU6050_FIFO_RATE_TO_DIVIDER(fifo_rate) \
+ ((INV_MPU6050_INTERNAL_FREQ_HZ / (fifo_rate)) - 1)
+#define INV_MPU6050_DIVIDER_TO_FIFO_RATE(divider) \
+ (INV_MPU6050_INTERNAL_FREQ_HZ / ((divider) + 1))
#define INV_MPU6050_REG_WHOAMI 117
--
2.17.0
--
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