[PATCH 4.9 49/60] iio: imu: inv_mpu6050: add accel lpf setting for chip >= MPU6500

Greg Kroah-Hartman
2017-06-19T15:30:36Z

From: Jean-Baptiste Maneyrol <JManeyrol@invensense.com>

commit 948588e25b8af5e66962ed3f53e1cae1656fa5af upstream.

Starting from MPU6500, accelerometer dlpf is set in a separate
register named ACCEL_CONFIG_2.
Add this new register in the map and set it for the corresponding
chips.

Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 39 ++++++++++++++++++++++++++---
drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h | 3 ++
2 files changed, 39 insertions(+), 3 deletions(-)

--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -41,6 +41,7 @@ static const int accel_scale[] = {598, 1
static const struct inv_mpu6050_reg_map reg_set_6500 = {
.sample_rate_div = INV_MPU6050_REG_SAMPLE_RATE_DIV,
.lpf = INV_MPU6050_REG_CONFIG,
+ .accel_lpf = INV_MPU6500_REG_ACCEL_CONFIG_2,
.user_ctrl = INV_MPU6050_REG_USER_CTRL,
.fifo_en = INV_MPU6050_REG_FIFO_EN,
.gyro_config = INV_MPU6050_REG_GYRO_CONFIG,
@@ -205,6 +206,37 @@ int inv_mpu6050_set_power_itg(struct inv
EXPORT_SYMBOL_GPL(inv_mpu6050_set_power_itg);

/**
+ * inv_mpu6050_set_lpf_regs() - set low pass filter registers, chip dependent
+ *
+ * MPU60xx/MPU9150 use only 1 register for accelerometer + gyroscope
+ * MPU6500 and above have a dedicated register for accelerometer
+ */
+static int inv_mpu6050_set_lpf_regs(struct inv_mpu6050_state *st,
+ enum inv_mpu6050_filter_e val)
+{
+ int result;
+
+ result = regmap_write(st->map, st->reg->lpf, val);
+ if (result)
+ return result;
+
+ switch (st->chip_type) {
+ case INV_MPU6050:
+ case INV_MPU6000:
+ case INV_MPU9150:
+ /* old chips, nothing to do */
+ result = 0;
+ break;
+ default:
+ /* set accel lpf */
+ result = regmap_write(st->map, st->reg->accel_lpf, val);
+ break;
+ }
+
+ return result;
+}
+
+/**
* inv_mpu6050_init_config() - Initialize hardware, disable FIFO.
*
* Initial configuration:
@@ -227,8 +259,7 @@ static int inv_mpu6050_init_config(struc
if (result)
return result;

- d = INV_MPU6050_FILTER_20HZ;
- result = regmap_write(st->map, st->reg->lpf, d);
+ result = inv_mpu6050_set_lpf_regs(st, INV_MPU6050_FILTER_20HZ);
if (result)
return result;

@@ -531,6 +562,8 @@ error_write_raw:
* would be alising. This function basically search for the
* correct low pass parameters based on the fifo rate, e.g,
* sampling frequency.
+ *
+ * lpf is set automatically when setting sampling rate to avoid any aliases.
*/
static int inv_mpu6050_set_lpf(struct inv_mpu6050_state *st, int rate)
{
@@ -546,7 +579,7 @@ static int inv_mpu6050_set_lpf(struct in
while ((h < hz[i]) && (i < ARRAY_SIZE(d) - 1))
i++;
data = d[i];
- result = regmap_write(st->map, st->reg->lpf, data);
+ result = inv_mpu6050_set_lpf_regs(st, data);
if (result)
return result;
st->chip_config.lpf = data;
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
@@ -28,6 +28,7 @@
* struct inv_mpu6050_reg_map - Notable registers.
* @sample_rate_div: Divider applied to gyro output rate.
* @lpf: Configures internal low pass filter.
+ * @accel_lpf: Configures accelerometer low pass filter.
* @user_ctrl: Enables/resets the FIFO.
* @fifo_en: Determines which data will appear in FIFO.
* @gyro_config: gyro config register.
@@ -47,6 +48,7 @@
struct inv_mpu6050_reg_map {
u8 sample_rate_div;
u8 lpf;
+ u8 accel_lpf;
u8 user_ctrl;
u8 fifo_en;
u8 gyro_config;
@@ -187,6 +189,7 @@ struct inv_mpu6050_state {
#define INV_MPU6050_FIFO_THRESHOLD 500

/* mpu6500 registers */
+#define INV_MPU6500_REG_ACCEL_CONFIG_2 0x1D
#define INV_MPU6500_REG_ACCEL_OFFSET 0x77

/* delay time in milliseconds */