On Tue, 22 May 2018 16:18:19 +0200
Jean-Baptiste Maneyrol <jmaneyrol@xxxxxxxxxxxxxx> wrote:
> 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>
Applied, thanks
Jonathan
> ---
> 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
>
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