On Wed, 12 Feb 2020 18:40:36 +0100
Jean-Baptiste Maneyrol <jmaneyrol@xxxxxxxxxxxxxx> wrote:
> i2c auxiliary mux is done by analog switches. You do not need to
> set them for every i2c transfer.
> Just set i2c bypass bit at init and do noting in i2c de/select.
>
> Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@xxxxxxxxxxxxxx>
Fair enough. Given we are making the decision based on DT and that
can't change on reprobing etc so this change makes sense to me I think.
It does leave us making rather odd use of the mux code, so I'd
just like Peter to take a quick look at this before I apply it.
Jonathan
> ---
> drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c | 71 +++++++++--------------
> 1 file changed, 28 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c
> index 1363d3776523..24df880248f2 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c
> @@ -20,38 +20,6 @@ static const struct regmap_config inv_mpu_regmap_config = {
>
> static int inv_mpu6050_select_bypass(struct i2c_mux_core *muxc, u32 chan_id)
> {
> - struct iio_dev *indio_dev = i2c_mux_priv(muxc);
> - struct inv_mpu6050_state *st = iio_priv(indio_dev);
> - int ret;
> -
> - mutex_lock(&st->lock);
> -
> - ret = inv_mpu6050_set_power_itg(st, true);
> - if (ret)
> - goto error_unlock;
> -
> - ret = regmap_write(st->map, st->reg->int_pin_cfg,
> - st->irq_mask | INV_MPU6050_BIT_BYPASS_EN);
> -
> -error_unlock:
> - mutex_unlock(&st->lock);
> -
> - return ret;
> -}
> -
> -static int inv_mpu6050_deselect_bypass(struct i2c_mux_core *muxc, u32 chan_id)
> -{
> - struct iio_dev *indio_dev = i2c_mux_priv(muxc);
> - struct inv_mpu6050_state *st = iio_priv(indio_dev);
> -
> - mutex_lock(&st->lock);
> -
> - /* It doesn't really matter if any of the calls fail */
> - regmap_write(st->map, st->reg->int_pin_cfg, st->irq_mask);
> - inv_mpu6050_set_power_itg(st, false);
> -
> - mutex_unlock(&st->lock);
> -
> return 0;
> }
>
> @@ -79,19 +47,20 @@ static bool inv_mpu_i2c_aux_bus(struct device *dev)
> }
> }
>
> -/*
> - * MPU9xxx magnetometer support requires to disable i2c auxiliary bus support.
> - * To ensure backward compatibility with existing setups, do not disable
> - * i2c auxiliary bus if it used.
> - * Check for i2c-gate node in devicetree and set magnetometer disabled.
> - * Only MPU6500 is supported by ACPI, no need to check.
> - */
> -static int inv_mpu_magn_disable(struct iio_dev *indio_dev)
> +static int inv_mpu_i2c_aux_setup(struct iio_dev *indio_dev)
> {
> struct inv_mpu6050_state *st = iio_priv(indio_dev);
> struct device *dev = indio_dev->dev.parent;
> struct device_node *mux_node;
> + int ret;
>
> + /*
> + * MPU9xxx magnetometer support requires to disable i2c auxiliary bus.
> + * To ensure backward compatibility with existing setups, do not disable
> + * i2c auxiliary bus if it used.
> + * Check for i2c-gate node in devicetree and set magnetometer disabled.
> + * Only MPU6500 is supported by ACPI, no need to check.
> + */
> switch (st->chip_type) {
> case INV_MPU9150:
> case INV_MPU9250:
> @@ -107,7 +76,24 @@ static int inv_mpu_magn_disable(struct iio_dev *indio_dev)
> break;
> }
>
> + /* enable i2c bypass when using i2c auxiliary bus */
> + if (inv_mpu_i2c_aux_bus(dev)) {
> + ret = inv_mpu6050_set_power_itg(st, true);
> + if (ret)
> + return ret;
> + ret = regmap_write(st->map, st->reg->int_pin_cfg,
> + st->irq_mask | INV_MPU6050_BIT_BYPASS_EN);
> + if (ret)
> + goto error;
> + ret = inv_mpu6050_set_power_itg(st, false);
> + if (ret)
> + goto error;
> + }
> +
> return 0;
> +error:
> + inv_mpu6050_set_power_itg(st, false);
> + return ret;
> }
>
> /**
> @@ -151,7 +137,7 @@ static int inv_mpu_probe(struct i2c_client *client,
> }
>
> result = inv_mpu_core_probe(regmap, client->irq, name,
> - inv_mpu_magn_disable, chip_type);
> + inv_mpu_i2c_aux_setup, chip_type);
> if (result < 0)
> return result;
>
> @@ -160,8 +146,7 @@ static int inv_mpu_probe(struct i2c_client *client,
> /* declare i2c auxiliary bus */
> st->muxc = i2c_mux_alloc(client->adapter, &client->dev,
> 1, 0, I2C_MUX_LOCKED | I2C_MUX_GATE,
> - inv_mpu6050_select_bypass,
> - inv_mpu6050_deselect_bypass);
> + inv_mpu6050_select_bypass, NULL);
> if (!st->muxc)
> return -ENOMEM;
> st->muxc->priv = dev_get_drvdata(&client->dev);
